US20140159461A1 - Armrest - Google Patents
Armrest Download PDFInfo
- Publication number
- US20140159461A1 US20140159461A1 US14/237,266 US201214237266A US2014159461A1 US 20140159461 A1 US20140159461 A1 US 20140159461A1 US 201214237266 A US201214237266 A US 201214237266A US 2014159461 A1 US2014159461 A1 US 2014159461A1
- Authority
- US
- United States
- Prior art keywords
- unlocking
- manipulation
- outer race
- race
- armrest
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
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- A—HUMAN NECESSITIES
- A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
- A47C—CHAIRS; SOFAS; BEDS
- A47C7/00—Parts, details, or accessories of chairs or stools
- A47C7/54—Supports for the arms
- A47C7/543—Supports for the arms movable to inoperative position
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60N—SEATS SPECIALLY ADAPTED FOR VEHICLES; VEHICLE PASSENGER ACCOMMODATION NOT OTHERWISE PROVIDED FOR
- B60N2/00—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles
- B60N2/58—Seat coverings
- B60N2/60—Removable protective coverings
- B60N2/6018—Removable protective coverings attachments thereof
- B60N2/6027—Removable protective coverings attachments thereof by hooks, staples, clips, snap fasteners or the like
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60N—SEATS SPECIALLY ADAPTED FOR VEHICLES; VEHICLE PASSENGER ACCOMMODATION NOT OTHERWISE PROVIDED FOR
- B60N2/00—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles
- B60N2/58—Seat coverings
- B60N2/60—Removable protective coverings
- B60N2/6018—Removable protective coverings attachments thereof
- B60N2/6036—Removable protective coverings attachments thereof by hook and loop-type fasteners
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60N—SEATS SPECIALLY ADAPTED FOR VEHICLES; VEHICLE PASSENGER ACCOMMODATION NOT OTHERWISE PROVIDED FOR
- B60N2/00—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles
- B60N2/58—Seat coverings
- B60N2/60—Removable protective coverings
- B60N2/6018—Removable protective coverings attachments thereof
- B60N2/6063—Removable protective coverings attachments thereof by elastic means
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60N—SEATS SPECIALLY ADAPTED FOR VEHICLES; VEHICLE PASSENGER ACCOMMODATION NOT OTHERWISE PROVIDED FOR
- B60N2/00—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles
- B60N2/75—Arm-rests
- B60N2/753—Arm-rests movable to an inoperative position
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60N—SEATS SPECIALLY ADAPTED FOR VEHICLES; VEHICLE PASSENGER ACCOMMODATION NOT OTHERWISE PROVIDED FOR
- B60N2/00—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles
- B60N2/75—Arm-rests
- B60N2/763—Arm-rests adjustable
- B60N2/767—Angle adjustment
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60N—SEATS SPECIALLY ADAPTED FOR VEHICLES; VEHICLE PASSENGER ACCOMMODATION NOT OTHERWISE PROVIDED FOR
- B60N2/00—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles
- B60N2/90—Details or parts not otherwise provided for
- B60N2002/905—Details or parts not otherwise provided for the head-rest or seat used as an anchorage point, for an object not covered by groups in B60N, e.g. for a canvas
Definitions
- the present invention relates to an armrest, in particular to an armrest using a clutch which can be downsized in an axial direction.
- a seat may be provided with an armrest.
- a certain improved armrest is configured such that the rotation of the armrest in a downward direction is locked within an angle range of the armrest in a use state, but the armrest is allowed to rotate freely in upward and downward directions within the other angle range of the armrest in a non-use state.
- the armrest disclosed in Patent Literature 1 employs as a one-way clutch mechanism for locking the rotation of the armrest in the downward direction a structure including a shaft and a coil spring wound around the outer periphery of the shaft.
- This configuration utilizes the characteristic of the coil spring such that when the rotation is made in the same direction as that in which the coil spring is wound up, the rotation of the coil spring with respect to the shaft is locked, but the rotation made in the reverse direction in which the coil spring is unlocked is allowed.
- Patent Literature 1 Japanese Laid-open Patent Application, Publication No. 2009-261828
- a one-way clutch mechanism using a coil spring as disclosed in Patent Literature 1 has a problem that the size of the coil spring in its axial direction is large.
- the size of the one-way clutch mechanism can be made relatively smaller in the axial direction; however, there is no known structure for unlocking the one-way clutch function in a predetermined angle range only by rotating the inner race or the outer race with a predetermined rotating action.
- the present invention seeks to provide an armrest using a clutch which can be downsized in the axial direction.
- the present invention also seeks to provide an armrest which can be reduced in weight. Further, the present invention seeks to provide an armrest in which a locally weakened portion would be unlikely to be produced even if the weight is reduced.
- the present invention also seeks to provide an armrest in which the inner race or the outer race can be prevented from receiving an excessive radial load.
- the present invention also seeks to provide an armrest of which the unlocking operation can be performed easily so that improvement in the easy operability can be achieved.
- the present invention seeks to provide a one-way clutch, as a clutch used for an armrest, which one-way clutch can be downsized in the axial direction and can allow the inner race and the outer race to be disengaged by a predetermined operation, thereby making the inner race and the outer race rotatable relative to each other.
- the present invention also seeks to provide a one-way clutch in which the inner race and the outer race can be prevented from receiving an excessive radial load.
- the present invention also seeks to provide a one-way of which the unlocking operation can be performed easily so that improvement in the easy operability can be achieved.
- Another object of the present invention is to reduce the weight of each of the constituting elements for the one-way clutch as well as to improve the rigidity of these constituting elements. Further, the present invention seeks to provide a one-way clutch which can allow each of the constituting elements for the one-way clutch to be manufactured easily as well as to reduce the number of the constituent parts.
- an armrest attachable to a seat back, comprising: an arm frame; and a clutch through which the arm frame is rotatably supported by the seat back, wherein the clutch comprises: an inner member configured to be fixed to one of the arm frame and the seat back; an outer race provided radially outward of the inner member and spaced apart from the inner member, and configured to be fixed to the other one of the arm frame and the seat back; an unlocking member provided coaxially with the inner member and the outer race, and configured to be rotatable relative to both of the inner member and the outer race; and an unlocking manipulation mechanism configured to actuate the unlocking member to unlock a locked state.
- the inner member may be an inner race; and the armrest may comprise a movable piece received in a pocket which is located between the inner race and the outer race and includes a portion whose radial width decreases with distance toward one circumferential direction; the unlocking member may have an unlocking piece arranged adjacent to one side of the movable piece in the one circumferential direction; and the unlocking manipulation mechanism may be configured to actuate the unlocking member to unlock the locked state in which the movable piece is trapped by inner walls of the pocket.
- the movable piece received in the pocket enables locking without using a shaft and a coil spring, and the unlocking member and the unlocking manipulation mechanism can unlock the locked state. Accordingly, the size in the axial direction can be reduced.
- the clutch may be a one-way clutch; and the unlocking manipulation mechanism may include a first manipulation member configured to be engaged with or fixed to the unlocking member, and a switching member configured to be coaxial with and rotatable relative to both of the inner race and the outer race and having a circumferential surface; the first manipulation member may contact the circumferential surface of the switching member, and the circumferential surface of the switching member may include a small diameter portion and a large diameter portion having a diameter greater than that of the small diameter portion; one of the inner race and the outer race may have a rotation restricting portion engageable with the switching member to restrict a relative rotation thereof with respect to the switching member in a predetermined angular range; the circumferential surface may be provided with a return engagement portion protruding radially from the circumferential surface, and when the first manipulation member is brought into contact with one of the small diameter portion and the large diameter portion, the unlocking member is allowed to rotate in the one circumferential direction to cause the movable piece to be
- the switching member when one of the inner race and the outer race is rotated with respect to the other one of them, the switching member relatively rotates with respect to the first manipulation member in conjunction with the rotation of the one of the inner race and the outer race. For this reason, if one of the inner race and the outer race is rotated, a contacting point of the first manipulation member which contacts the circumferential surface of the switching member is switched between the large diameter portion and the small diameter portion in accordance with the phase (direction) of the switching member. Since the first manipulation member is engaged with or fixed to the unlocking member, the unlocking member slightly rotates in a circumferential direction. This can cause the unlocking piece of the unlocking member to rotate in one circumferential direction or in the other circumferential direction.
- the movable piece In the case of rotation in the one circumferential direction (i.e., direction in which the radial width of the pocket decreases), the movable piece is trapped and thus locked in the pocket. Namely, the inner race and the outer race are engaged with each other so that they are not rotatable relative to each other.
- the unlocking piece pushes the movable piece toward the direction in which the radial width of the pocket becomes larger to unlock the locked state. In other words, the inner race and the outer race become freely rotatable relative to each other.
- the armrest including the movable piece in the pocket can perform locking and locking operations by rotating the armrest.
- the inner race having the rotation restricting portion or the outer race having the rotation restricting portion can be freely rotatable relative to the switching member in the range where the rotation restricting portion does not restrict the relative rotation with respect to the switching member.
- the inner race having the rotation restricting portion or the outer race having the rotation restricting portion rotates together with the switching member.
- the switching member and one of the inner race and the outer race rotate together, the switching member and the first manipulation member rotate relatively to each other, so that the contacting point of the first manipulation member which contacts the circumferential surface of the switching member is switched between the small diameter portion and the large diameter portion.
- the first manipulation member which is in contact with the large diameter portion after rotating one of the inner race and the outer race to ride over the return engagement portion, can engage with the return engagement portion by the reverse rotation of one of the inner race and the outer race and cause the switching member to rotate in the reverse direction.
- the switching member since not only is the switching member rotatable relative to the inner race or the outer race in one direction but also rotatable in the reverse direction, one of the inner race and the outer race can be moved back and forth relative to the other one of them.
- the locked state and the unlocked state of the inner race and the outer race can be switched over in accordance with whether the first manipulation member contacts with the large diameter portion or the small diameter portion, both of which are provided on the circumferential surface of the switching member.
- the switching member relatively rotates with respect to the first manipulation member includes the case where, as viewed from outside, the first manipulation member is rotatable while the switching member is stationary. This is because, in this example too, the switching member rotates relatively with respect to the first manipulation member.
- the inner race may comprise a first metal part constituting a part of the inner walls of the pocket, and a first resin part; and a rugged portion formed on an inner periphery of the first metal part and a rugged portion formed on an outer periphery of the first resin part may be engaged with each other such that the first metal part and the first resin part are assembled together to prevent relative slippage in circumferential directions.
- the above-described armrest may further comprise an urging member arranged to urge the movable piece toward the one circumferential direction
- the inner race may comprise a first metal part constituting a part of the inner walls of the pocket, and a first resin part; a rugged portion formed on an inner periphery of the first metal part and a rugged portion formed on an outer periphery of the first resin part may be engaged with each other such that the first metal part and the first resin part are assembled together to prevent relative slippage in circumferential directions;
- the first metal part may have an urging member receiving recess which is recessed toward a center of the first metal part to receive the urging member; and the rugged portion of the first metal part may have a protrusive portion protruding toward the center of the first metal part, and the protrusive portion may be arranged radially inward of the urging member receiving recess.
- weight reduction can be achieved by using the first resin part while the strength required for the inner race is provided by the first metal part, and further the radial width of the first metal part is increased to avoid the presence of a locally weakened portion that would occur at the first metal part.
- the outer race may comprise a second metal part constituting a part of the inner walls of the pocket, and a second resin part, and a rugged portion formed on an outer periphery of the second metal part and a rugged portion formed on an inner periphery of the second resin part may be engaged with each other such that the second metal part and the second resin part are assembled together to prevent relative slippage in circumferential directions.
- the rugged portion of the second metal part has a protrusive portion protruding radially outward, and when the clutch is in the locked state, the protrusive portion is positioned radially outward of the movable piece.
- the contact pressure of the movable piece can be received by a high rigidity portion of the second metal part, which can ensure the strength of the second metal part.
- the unlocking member has an extension portion extending radially outward, and that the first manipulation member engages with the unlocking member at the extension portion, and the first manipulation member is arranged radially outward of the outer race in a region where the first manipulation member and the outer race overlap in an axial direction.
- the size in the axial direction is less likely to increase even if the first manipulation member is provided. In other words, the size in the axial direction can be reduced.
- the inner walls of the pocket have a projection at one side of the movable piece in the one circumferential direction, and when the inner race and the outer race are forcibly and relatively rotated in a locking direction, the projection contacts the movable piece.
- the unlocking manipulation mechanism may be engaged with or fixed to the unlocking member and include a second manipulation member extending toward a distal end of the arm frame, and when the second manipulation member is manipulated to rotate the unlocking member in the other circumferential direction, the movable piece may be allowed to be unlocked.
- the unlocking manipulation mechanism is engaged with or fixed to the unlocking member and includes a second manipulation member extending toward a distal end of the arm frame; that when the second manipulation member is manipulated to rotate the unlocking member in the other circumferential direction, the movable piece is allowed to be unlocked: that the first manipulation member is provided arcuately around an axis of rotation of the arm frame, and the second manipulation member is provided along a longitudinal direction of the arm flame; and that the first manipulation member and the second manipulation member are arranged so as not to overlap each other as viewed from an axial direction.
- the size in the axial direction is less likely to increase even if the first manipulation member and the second manipulation member are provided.
- the small diameter portion and the large diameter portion are formed as flanges extending from a peripheral edge of the switching member in an axial direction of the switching member.
- the flange constituting the small diameter portion and the flange constituting the large diameter portion are connected to each other. This can improve the rigidity of the switching member.
- the return engagement portion is integrally molded with the switching member. This can ease the manufacture of the return engagement portion, and the number of the constituent parts can be reduced.
- the extension portion is integrally molded with the unlocking member. This can ease the manufacture of the extension portion, and the number of the constituent parts can be reduced.
- a first attachment member is fixed to the inner race and a second attachment member is fixed to the outer race; that one of the first attachment member and the second attachment member has a stopper which protrudes toward the one-way clutch and is engageable with the inner race or the outer race fixed to the other one of the first attachment member and the second attachment member to restrict a rotation range of the one of the first attachment member and the second attachment member; and that the stopper is arranged in a region where the stopper and the extension portion overlap in the axial direction and where the stopper and the extension portion do not overlap as viewed from the axial direction.
- the extension portion and the stopper are arranged in a region where they do not overlap each other as viewed from the axial direction and where they overlap in the axial direction, the size of the armrest can be further reduced in the axial direction.
- a clutch used for the above-described armrest comprises: an inner race; an outer race provided radially outward of the inner race and spaced apart from the inner race; a movable piece received in a pocket which is located between the inner race and the outer race and includes a portion whose radial width decreases with distance toward one circumferential direction; an unlocking member provided coaxial with the inner race and the outer race and configured to be rotatable relative to both of the inner race and the outer race: a first manipulation member configured to be engaged with or fixed to the unlocking member; and a switching member configured to be relatively rotatable with respect to the first manipulation member in conjunction with rotation of one of the inner race and the outer race and having a circumferential surface, wherein the unlocking member has an unlocking piece arranged adjacent to one side of the movable piece in the one circumferential direction, wherein the first manipulation member contacts the circumferential surface of the switching member, and the circumferential surface of the switching member includes a small diameter portion and a large diameter portion having a
- the switching member when one of the inner race and the outer race is rotated with respect to the other one of them, the switching member relatively rotates with respect to the first manipulation member in conjunction with the rotation of the one of the inner race and the outer race. For this reason, if one of the inner race and the outer race is rotated, a contacting point of the first manipulation member which contacts the circumferential surface of the switching member is switched between the large diameter portion and the small diameter portion in accordance with the phase (direction) of the switching member. Since the first manipulation member is engaged with or fixed to the unlocking member, the unlocking member slightly rotates in a circumferential direction. This can cause the unlocking piece of the unlocking member to rotate in one circumferential direction or in the other circumferential direction.
- the movable piece In the case of rotation in the one circumferential direction (i.e., direction in which the radial width of the pocket decreases), the movable piece is trapped and thus locked in the pocket. Namely, the inner race and the outer race are engaged with each other so that they are not rotatable relative to each other.
- the unlocking piece pushes the movable piece toward the direction in which the radial width of the pocket becomes larger to unlock the locked state. In other words, the inner race and the outer race become freely rotatable relative to each other.
- the one-way clutch including the movable piece provided in the pocket can perform locking and locking operations by rotating one of the inner race and the outer race. Namely, the size of the one-way clutch can be reduced in the axial direction, and the one-way clutch can allow the engagement between the inner race and the outer race to be disengaged by a predetermined operation, thereby slipping the inner race and the outer race relative to each other.
- the switching member relatively rotates with respect to the first manipulation member includes the case where, as viewed from outside, the first manipulation member is rotatable while the switching member is stationary. This is because, in this example too, the switching member rotates relatively with respect to the first manipulation member.
- the switching member may be configured to be rotatable relative to both of the inner race and the outer race, and one of the inner race and the outer race may have a rotation restricting portion engageable with the switching member to restrict a relative rotation thereof with respect to the switching member in a predetermined angular range, and further the circumferential surface may be provided with a return engagement portion protruding radially outward from the circumferential surface.
- the inner race having the rotation restricting portion or the outer race having the rotation restricting portion can be freely rotatable relative to the switching member in the range where the rotation restricting portion does not restrict the relative rotation with respect to the switching member.
- the inner race having the rotation restricting portion or the outer race having the rotation restricting portion can rotate together with the switching member.
- the first manipulation member which is in contact with the large diameter portion after rotating one of the inner race and the outer race to ride over the return engagement portion, can engage with the return engagement portion by the reverse rotation of one of the inner race and the outer race and cause the switching member to rotate in the reverse direction.
- the switching member since not only is the switching member rotatable relative to the inner race or the outer race in one direction but also rotatable in the reverse direction, one of the inner race and the outer race can be moved back and forth relative to the other one of them.
- the locked state and the unlocked state of the inner race and the outer race can be switched in accordance with whether the first manipulation member contacts with the large diameter portion or the small diameter portion, both of which are provided on the circumferential surface of the switching member.
- the unlocking member has an extension portion extending radially outward, and that the first manipulation member engages with the unlocking member at the extension portion, and the first manipulation member is arranged radially outward of the outer race in a region where the first manipulation member and the outer race overlap in an axial direction.
- the size in the axial direction is less likely to increase even if the first manipulation member is provided. In other words, the size in the axial direction can be reduced.
- the inner walls of the pocket have a projection at one side of the movable piece in the one circumferential direction, and when the inner race and the outer race are forcibly and relatively rotated in a locking direction, the projection contacts the movable piece.
- the above-described one-way clutch may further comprise a second manipulation member engaged with or fixed to the unlocking member, and it is preferable that when the second manipulation member is manipulated to rotate the unlocking member in the other circumferential direction, the inner race and the outer race are allowed to be unlocked.
- the small diameter portion and the large diameter portion are formed as flanges extending from a peripheral edge of the switching member in an axial direction of the switching member.
- the flange constituting the small diameter portion and the flange constituting the large diameter portion are connected to each other. This can improve the rigidity of the switching member.
- the return engagement portion is integrally molded with the switching member. This can ease the manufacture of the return engagement portion, and the number of the constituent parts can be reduced.
- the extension portion is integrally molded with the unlocking member. This can ease the manufacture of the extension portion, and the number of the constituent parts can be reduced.
- a first attachment member is fixed to the inner race and a second attachment member is fixed to the outer race: that one of the first attachment member and the second attachment member has a stopper which protrudes toward the one-way clutch and is engageable with the inner race or the outer race fixed to the other one of the first attachment member and the second attachment member to restrict a rotation range of the one of the first attachment member and the second attachment member; and that the stopper is arranged in a region where the stopper and the extension portion overlap in the axial direction and where the stopper and the extension portion do not overlap as viewed from the axial direction.
- the extension portion and the stopper are arranged in a region where they do not overlap each other as viewed from the axial direction and where they overlap in the axial direction, the size of the one-way clutch can be further reduced in the axial direction.
- FIG. 1 is a perspective view of a seat with an armrest.
- FIG. 2 shows left-side views explaining the motion of the armrest, in which (a) shows a stowing operation, and (b) shows a folding out operation.
- FIG. 3 is an exploded perspective view of the armrest.
- FIG. 4 includes (a) a right-side view of an outer race, and (b) a cross-sectional view taken along the line IV-IV of (a).
- FIG. 5 is a view showing the inner structure of a one-way clutch.
- FIG. 6 shows views explaining the motion of a roller, in which (a) shows rotation in an unlocking direction, (b) shows rotation in a locking direction, and (c) shows the roller in an unlocked state.
- FIG. 7 includes view of the one-way clutch observed when the armrest is in a fold out position (position A), in which (a) shows a left-side view of the one-way clutch, and (b) shows a view of the one-way clutch as seen from below.
- FIG. 8 is a left-side view of the one-way clutch in a locked state when the armrest is located near the position B.
- FIG. 9 is a left-side view of the one-way clutch in an unlocked state when the armrest is located near the position B.
- FIG. 10 is a left-side view of the one-way clutch in an unlocked state when the armrest is in a stowed position (position C).
- FIG. 11 is a left-side view of the one-way clutch in the unlocked state when the armrest is rotated from the stowed position toward the fold out position and is located near the position A.
- FIG. 12 is an enlarged view showing the structure around the roller of the one-way clutch according to a modified embodiment.
- a seat S includes a seat back S 1 and a seat bottom S 2 , and an armrest (first attachment member) R is fixed to the seat back (second attachment member) S 1 through a one-way clutch 1 which is an example of a clutch.
- first attachment member first attachment member
- second attachment member second attachment member
- directions of front, rear, right, left, upper and lower are designated as from the view point of an occupant sitting on the seat S, and for example, a view of the armrest R as seen from left (e.g., FIG. 2 ) is referred to as a left-side view of the armrest R for convenience.
- the armrest R is rotatable between a fold out state (position A) in which the distal end of the armrest faces frontward and a stowed state (position C) in which the distal end of the armrest faces upward.
- position A a fold out state
- position C a stowed state
- the armrest R is allowed to rotate upward but is not allowed to rotate downward.
- the state in which the armrest is not allowed to rotate downward is referred to as being “locked” (locked state) in this specification.
- the armrest R is allowed to rotate both upward and downward in a range from the position B to the position C.
- This state is referred to as being unlocked (unlocked state).
- the armrest R is allowed to rotate both upward and downward during the folding out operation for moving the armrest R from the stowed position (position C) toward the fold out position (position A). In other words, the armrest R is in the unlocked state.
- the armrest R In the folding out operation, when the armrest R is completely rotated to the position A, it returns to the locked state. However, independent of the above operation, the armrest R can be unlocked in any posture by depressing a lower portion of a manipulation lever R 2 provided at the distal end of the armrest R.
- the armrest R includes an arm frame R 1 made of plastic resin; although not shown in the drawings, a cushion and a skin are provided outside the arm frame R 1 .
- the arm frame R 1 has a shape extending in the front-rear direction of FIG. 3 , and the rear end portion of the arm frame R 1 is rotatably attached to the seat back S 1 through the one-way clutch 1 using a bolt (not shown) or the like.
- an inner race 2 B made of plastic resin, which is an example of a first resinous member, is formed on the left side.
- a rugged shaped portion (rugged portion) 21 B having different outer diameters arranged at a constant pitch.
- stoppers R 4 protruding leftward (toward the one-way clutch 1 ) at two opposite positions across the plastic inner race 2 B.
- the stoppers R 4 are engageable with stoppers 38 of an outer race 3 (one of the inner race 2 and the outer race 3 fixed to the seat back S 1 ) to be described later in a circumferential direction, to thereby restrict a relative rotation range of the outer race 3 and the arm frame R 1 .
- the one-way clutch 1 includes the inner race 2 , the outer race 3 , rollers 71 as an example movable pieces, and springs 72 as an example of urging members.
- the one-way clutch 1 further includes, as an unlocking manipulation mechanism for unlocking a locked state in which each roller 71 is trapped by the inner walls of a pocket PK, an unlocking member 4 , a switching member 5 , and a manipulation rod 6 .
- the inner race 2 consists of an inner race 2 A made of metal which is an example of a first metal part, and the plastic inner race 2 B as described above.
- the metal inner race 2 A has a rugged shaped portion (rugged portion) 21 A at the inner periphery of a center through-hole thereof, and the rugged shaped portion 21 B of the plastic inner race 2 B and the rugged shaped portion 21 A of the metal inner race 2 A are engaged with each other such that the metal inner race 2 A and the plastic inner race 2 B are assembled together to prevent relative slippage in circumferential directions. Accordingly, the inner race 2 is fixed to the arm frame R 1 . Further, since the inner race 2 is made by assembling the metal inner race 2 A and the plastic inner race 2 B together, weight reduction can be achieved while ensuring the required strength.
- the metal inner race 2 A has three roller receiving portions 26 equiangularly arranged and protruding radially outward.
- the outer peripheral surface of each roller receiving portion 26 is provided with a recess which is recessed toward a center of the metal inner race 2 A, and the recess includes a slanted surface 22 whose radius gradually increases with distance in the clockwise direction of FIG. 5 (hereinafter, clockwise and anticlockwise directions are referred to based on the directions of FIG. 5 ), and an urging member receiving recess 23 which is adjacent to one end of the slanted surface 22 in the anticlockwise direction and recessed toward the center beyond the slanted surface 22 .
- a stopper portion 24 for regulating the positional relation between an unlocking piece 41 to be described later and the metal inner race 2 A is provided at an end of the slanted surface 22 in the clockwise direction. Further, a restriction wall 25 for restricting posture of a spring 72 is provided at one side of the urging member receiving recess 23 in the anticlockwise direction.
- the rugged shaped portion 21 A at the inner periphery of the metal inner race 2 A has protrusive portions (portions protruding radially inward; see reference numeral 21 X of FIG. 5 ), and the protrusive portions are arranged radially inward of the urging member receiving recesses 23 . This can increase the radial width of the metal inner race 2 A to avoid the presence of locally weakened portions that would occur at the metal inner race 2 A.
- the outer race 3 is provided radially outward of the inner race 2 (metal inner race 2 A) and spaced apart from the inner race 2 .
- the inner periphery 31 of the outer race 3 forms a circular cylindrical surface, and pockets PK each receiving a roller 71 and a spring 72 are formed between the slanted surface 22 of the metal inner race 2 A and the inner periphery 31 of the outer race 3 . Since the radius along the slanted surface 22 decreases with distance toward the clockwise direction while the inner periphery 31 of the outer race 3 has the circular cylindrical surface, each pocket PK includes a portion whose radial width decreases with distance toward one circumferential direction (i.e., clockwise direction).
- Each unlocking piece 41 is arranged in the pocket PK adjacent to one side of the roller 71 in the one circumferential direction (i.e., clockwise direction side).
- the unlocking member 4 has the unlocking pieces 41 .
- a spring 72 made of a substantially U-shaped leaf spring is arranged adjacent to the other side of the roller 71 in the one circumferential direction (i.e., anticlockwise direction side). As shown in an enlarged view in FIG. 6 ( a ), the spring 72 is received at its bent portion 72 A in the urging member receiving recess 23 such that one arm 72 B abuts on the restriction wall 25 and the other arm 72 C urges the roller 71 in the clockwise direction.
- the roller 71 By this urging force the roller 71 is brought into contact with the inner walls (i.e., the slanted surface 22 and the inner periphery 31 ) of the pocket PK to thereby prevent backlash. It should be noted that the urging force of the spring 72 is so weak as necessary and sufficient to prevent the backlash of the roller 71 , but not so strong that the roller 71 gets trapped in the inner walls of the pocket PK to lock the relative rotation between the inner race 2 and the outer race 3 .
- the outer race 3 consists of a metal outer race 3 A as an example of a second metal member and a plastic outer race 3 B as an example of a second resin member.
- the metal outer race 3 A has an inner periphery 31 in the form of a circular cylindrical surface, and an outer periphery thereof has a rugged shaped portion (rugged portion) 32 A having different outer diameters arranged at a constant pitch.
- the plastic outer race 3 B has an inner surface provided with a rugged shaped portion 32 B corresponding to the rugged shaped portion 32 A, and the rugged shaped portion 32 A of the metal outer race 3 A and the rugged shaped portion 32 B of the plastic outer race 3 B are engaged with each other such that the metal outer race 3 A and the plastic outer race 3 B are assembled together to prevent relative slippage in circumferential directions.
- the outer race 3 is made by assembling the metal outer race 3 A and the plastic outer race 3 B, weight reduction can be achieved while ensuring the required strength.
- the one-way clutch 1 is in a lockable state, that is in a range from the position A to the position B during the stowing operation of the armrest R as shown in FIG. 2 ( a )
- protrusive portions portions protruding radially outward
- the rugged portion 32 A formed on the outer periphery of the metal outer race 3 A are arranged radially outward of the rollers 71 . According to this configuration, the contact pressures of the rollers 71 can be received by high rigidity portions of the metal outer race 3 A, which can ensure the strength of the metal outer race 3 A.
- a circular support shaft 34 protrudes outward at the left-side surface of the plastic outer race 3 B.
- protrusions 39 are provided on the support shaft 34 ; the protrusions 39 are engageable with the seat back S 1 to prevent the rotation of the outer race 3 relative to the seat back S 1 .
- Two stoppers 38 protruding radially outward are provided on the outer periphery of the plastic outer race 3 B.
- a rotation restricting portion 35 is provided at an outer edge portion of the right-side surface of the plastic outer race 3 ; the rotation restricting portion 35 protrudes outward to restrict a relative rotation of the outer race 3 B with respect to the switching member 5 in a predetermined angular range.
- the unlocking member 4 is configured to unlock the locked state in which each roller 71 is trapped by the inner walls of the corresponding pocket PK.
- the unlocking member 4 is made of a plate-like ring member, and has an extension portion 42 extending radially outward (e.g., lower direction in FIG. 3 ).
- the extension portion 42 is integrally molded with the main body of the unlocking member 4 and thus can be easily manufactured and the number of constituent parts can be reduced.
- the unlocking member 4 is configured such that the extension portion 42 is positioned between the two stoppers R 4 when it is assembled with the plastic inner race 21 B.
- the extension portion 42 is provided in a region where the extension portion 42 and the stoppers R 4 overlap in the axial direction and where the extension portion 42 and the stoppers R 4 do not overlap as viewed from the axial direction as shown in FIG. 7 ( a ) and FIGS. 8-10 . Accordingly, the one-way clutch 1 (armrest R) can be downsized in the axial direction by effectively utilizing the space.
- the extension portion 42 is provided with an engagement projection 43 with which the manipulation rod 6 is engaged.
- An inner peripheral portion 44 of the unlocking member 4 has a diameter corresponding to the outer diameter of the plastic inner race 2 B, so that when the inner peripheral portion 44 is fitted onto the plastic inner race 2 B, the unlocking member 4 is coaxial with the inner race 2 and rotatable relative to the inner race 2 . Further, since the inner race 2 and the outer race 3 are rotatable relative to each other and they are not fixed to each other, the unlocking member 4 is coaxial with the inner race 2 and the outer race 3 and rotatable relative to both of the inner race 2 and the outer race 3 .
- the unlocking pieces 41 as described above are provided protrusively at the left-side surface of the unlocking member 4 corresponding to each of the rollers 71 .
- the switching member 5 is configured to cooperate with the manipulation rod 6 to switch over between the locked state and the unlocked state of the inner race 2 and the outer race 3 (rollers 71 ) actuated by the rotating action of the armrest R.
- the switching member 5 is made by a plate-like ring member, and rotatable relative to the outer race 3 because the circular inner peripheral portion 54 is engaged with the support shaft 34 of the outer race 3 .
- Restriction walls 56 , 57 protrude radially outward from the outer periphery of the switching member 5 at a position obliquely frontward and downward and at a position downward, respectively, and as seen in FIG.
- the rotation restricting portion 35 of the outer race 3 is located between the restriction wall 56 and the restriction wall 57 .
- the switching member 5 and the outer race 3 are relatively rotatable in a range from where the rotation restricting portion 35 contacts the restriction wall 56 to where the rotation restricting portion 35 contacts the restriction wall 57 .
- the switching member 5 is rotatable relative to both of the inner race 2 and the outer race 3 . It should be noted that while the rotation restricting portion 35 is in contact with the restriction wall 56 or the restriction wall 57 , the outer race 3 and the switching member 5 can rotate together in a corresponding rotating direction.
- the switching member 5 includes a small diameter portion 51 of which the outer peripheral surface extends from rear side to upper side in FIG. 3 coaxially with the inner peripheral portion 54 .
- the small diameter portion 51 is formed with a flange extending from the peripheral edge of the switching member 5 in the axial direction (leftward). With this configuration, while the weight of the switching member 5 can be reduced, it is ensured to enlarge the sliding contact surface of the switching member 5 in contact with the contacting portion 63 of a manipulation rod 6 to be described later.
- the switching member 5 includes a large diameter portion 52 of which the outer peripheral surface extends from rear side to the lower restriction wall 57 in FIG. 3 coaxially with the inner peripheral portion 54 and which has a diameter slightly greater than that of the small diameter portion 51 .
- the large diameter portion 52 is formed with a flange extending from the peripheral edge of the switching member 5 in the axial direction (leftward), so that the sliding contact surface in contact with the contacting portion 63 of the manipulation rod 6 is ensured.
- the flange of the small diameter portion 51 and the flange of the large diameter portion 52 are connected to each other, so that the peripheral portion of the switching member 5 has high rigidity.
- a return engagement portion 53 protruding radially outward and shaped as a small peaked projection.
- the return engagement portion 53 is integrally molded with the main body of the switching member 5 on the flange portions forming the small diameter portion 51 and the large diameter portion 52 . With this configuration, the return engagement portion 53 can be easily manufactured and the number of constituent parts can be reduced.
- restriction wall 57 is adjacent to one end of the large diameter portion 52 in the clockwise direction and protrudes radially outward beyond the large diameter portion 52 , so that when the contacting portion 63 slides on the large diameter portion 52 , the restriction wall 57 restricts the sliding range of the contacting portion 63 .
- the manipulation rod 6 is configured to cooperate with the switching member 5 to manipulate locking and unlocking of the rollers 71 in accordance with the rotating action of the armrest R and the manipulation of the user.
- the manipulation rod 6 is made of a metal rod having rigidity to allow a slight deformation thereof, and includes a first manipulation portion 61 which is an example of a first manipulation member and extends in a circular arc shape, and a second manipulation portion 62 which is an example of a second manipulation member and extends straight along the longitudinal direction of the arm frame R 1 from the front end of the first manipulation portion 61 toward the distal end of the arm frame R 1 .
- the first manipulation portion 61 and the second manipulation portion 62 are integrally formed, and they do not overlap as viewed from the axial direction of the armrest R. This can reduce the size of the armrest R in the axial direction. Further, since the second manipulation portion 62 is provided along the lower edge of the arm frame R 1 , and the extension portion 42 of the unlocking member 4 extends downward, it is possible to prevent the armrest R from bulging upward as compared with the configuration in which the second manipulation portion 62 and the extension portion 42 are provided at the upper side of the arm frame R 1 .
- An engagement hole 69 is formed in a connecting portion which connects the first manipulation portion 61 and the second manipulation portion 62 , and the engagement hole 69 is engaged with the engagement projection 43 provided on the extension portion 42 of the unlocking member 4 .
- the first manipulation portion 61 is arranged radially outward of the outer race 3 in a position such that the first manipulation portion 61 and the outer race 3 overlap in the axial direction (see FIG. 7 ( b )).
- the first manipulation portion 61 extends arcuately from a portion with the engagement hole 69 along the outer periphery of the outer race 3 , through 90 degrees from lower side to rear side of FIG. 7 ( a ), and the contacting portion 63 formed by bending the first manipulation portion 61 leftward at the distal end thereof contacts the outer peripheral surface of the switching member 5 (e.g., small diameter portion 51 in the example of FIG. 7 ( a )) from the radially outward side. Since the contacting portion 63 is provided by bending, the rigidity of the contacting portion 63 is enhanced.
- the position of the contacting portion 63 with respect to the engagement hole 69 is not limited to that in which it is separated by 90 degrees in phase about the center of rotation however, it is preferable that this position is separated away from the straight line connecting the engagement hole 69 and the center of the small diameter portion 51 and from the straight line connecting the engagement hole 69 and the center of the large diameter portion 52 as far as possible. Since the first manipulation portion 61 is engaged with the unlocking member 4 , and the unlocking member 4 is relatively rotatable with respect to the outer race 3 , the switching member 5 is relatively rotatable with respect to the first manipulation portion 61 in conjunction with the outer race 3 .
- an attachment hole 65 is formed at the front end of the second manipulation portion 62 .
- the manipulation lever R 2 swingable around a shaft R 3 is provided at the front end of the arm frame R 1 , and the front end of the second manipulation portion 62 is connected to the manipulation lever R 2 at a portion thereof below the shaft R 3 using the attachment hole 65 by a screw 68 . Accordingly, when the lower end portion of the manipulation lever R 2 is depressed rearward, the unlocking member 4 is caused to rotate in the anticlockwise direction of FIG. 7 ( a ) through the second manipulation portion 62 .
- the return engagement portion 53 protrudes from the small diameter portion 51 and the large diameter portion 52 , and when the switching member 5 and the rotation restricting portion 35 are not engaged with each other (i.e., when the rotation of the switching member 5 is not restricted by the engagement between the rotation restricting portion 35 and the restriction wall 56 or by the engagement between the rotation restricting portion 35 and the restriction wall 57 ), the switching member 5 can be rotated by the contacting portion 63 engaged with the switching member 5 .
- the return engagement portion 53 protrudes to such an extent that when the rotation of the switching member 5 is restricted by the engagement between the rotation restricting portion 35 and the restriction wall 56 or by the engagement between the rotation restricting portion 35 and the restriction wall 57 , the first manipulation portion 61 is caused to deform to allow the contacting portion 63 to ride over the return engagement portion 53 .
- the roller 71 When attention is focused on the roller 71 , the roller 71 is relatively moved toward a wider portion of a wedge-shaped space formed by the inner walls (slanted surface 22 and inner periphery 31 ) of the pocket PK; actually, the roller 71 does not move relatively in the pocket PK because the spring 72 urges the roller 71 . Accordingly, the contact pressure between the inner walls of the pocket PK and the roller 71 does not increase, and hence the roller 71 is allowed to rotate anticlockwise in FIG. 6 ( a ) and the inner race 2 can be rotated relatively with respect to the outer race 3 . The rotation in this direction is referred to as rotation in the unlocking direction.
- the roller 71 is trapped by the inner walls of the pocket PK and the contact pressure between the pocket PK and the roller 71 increases, which inhibits the roller 71 from rotating relative to the inner race 2 and the outer race 3 . In other words, the inner race 2 and the outer race 3 are locked.
- the armrest R operates as follows.
- the deformation amount of the first manipulation portion 61 (the moving distance of the contacting portion 63 in the radially outward direction if the engagement hole 69 is regarded as a stationary portion) is slightly smaller than the difference between the radius of the small diameter portion 51 and the radius of the large diameter portion 52 , and the sum of the moving distance of the contacting portion 63 resulting from the deformation of the first manipulation portion 61 and the moving distance of the contacting portion 63 resulting from the rotation of the unlocking member 4 substantially corresponds to the difference between the radius of the small diameter portion 51 and the radius of the large diameter portion 52 .
- each of the unlocking pieces 41 urges the roller 71 anticlockwise into the unlocked state.
- the inner race 2 arm frame R 1
- the contacting portion 63 is in contact with the large diameter portion 52 .
- the contacting portion 63 will not slide on the large diameter portion 52 , but instead the first manipulation portion 61 (contacting portion 63 ) and the switching member 5 together rotate anticlockwise, and the contacting portion 63 may slide on the large diameter portion 52 in the anticlockwise direction after the restriction wall 56 comes into contact with the rotation restricting portion 35 ; however, irrespective of the order of the motion of the contacting portion 63 , the contacting portion 63 moves into the state as shown in FIG. 11 . In the state shown in FIGS.
- FIG. 11 shows a state in which the arm frame R 1 is located slightly above the position A.
- the unlocking member 4 slightly rotates clockwise relative to the inner race 2 . This can cause each of the unlocking pieces 41 not to urge the roller 71 , and as described above with reference to FIGS. 6 ( a ) and ( b ), the inner race 2 and the outer race 3 return to the lockable state.
- the locked state and the unlocked state can be switched over by the predetermined rotating action of the armrest R (arm frame R 1 ). Further, since the one-way clutch 1 is not of the type using a coil spring wound around a shaft as in the case of the conventional armrest, and is configured to use rollers 71 received in wedge-shaped pockets PK, the size of the one-way clutch 1 can be reduced in the axial direction.
- the switching member 5 since the switching member 5 is rotatable relative to both of the inner race 2 and the outer race 3 , and the rotation range thereof is restricted by the rotation restricting portion 35 and the restriction walls 56 , 57 , and further the return engagement portion 53 is provided on the switching member 5 , the arm frame R 1 can be moved from up to down and from down to tip.
- depressing the lower end portion of the manipulation lever R 2 causes the unlocking member 4 to rotate anticlockwise through the second manipulation portion 62 .
- This can allow the user to unlock at any time irrespective of the orientation of the arm frame R 1 and/or the position of the contacting portion 63 in contact with the switching member 5 . In other words, the easy operability can be improved.
- al inner wall of a pocket PK may be provided with a projection 22 A at one side of the roller 71 in a direction where the radial width of the pocket PK decreases and adjacent to the roller 71 .
- the projection 22 A and the roller 71 are brought into contact so that the contact pressure between the roller 71 and the inner walls of the pocket PK does not increase any further. This can prevent the inner race 2 and the outer race 3 from receiving an excessive radial load.
- the projection may be provided on the inner periphery 31 of the outer race 3 .
- roller receiving portions 26 are provided in the above embodiment; however, the number of the roller receiving portions 26 is not limited as long as one or more roller receiving portion are provided.
- the more roller receiving portions 26 are preferable.
- the inner race 2 is fixed to the arm frame R 1 and the outer race 3 is fixed to the seat back S 1 ; however, the outer race 3 may be fixed to the arm frame R 1 and the inner race 2 may be fixed to the seat back S 1 instead.
- the orientation of the wedge-shaped pocket PK may be changed where appropriate.
- Locking and unlocking the inner race 2 and the outer race 3 in accordance with the rotation of the unlocking member 4 in either of the circumferential directions can be modified where necessary in consideration of the orientation of the wedge-shaped pockets PK.
- rollers 71 are exemplified as an example of movable pieces: however, the movable pieces may be balls. As long as the sliding property is properly set, block-shaped or wedge-shaped small pieces each of which does not roll over relative to the inner race 2 and the outer race 3 may be used.
- the first manipulation member may not be engaged with the unlocking member but may be fixed thereto. Even in this configuration, if the rigidity of the first manipulation member is set to allow the contacting portion of the first manipulation member to deform to ride over from the small diameter portion to the large diameter portion, the switching between locking and unlocking can be made by the rotation of the unlocking member. Similarly, the second manipulation portion may be fixed to the unlocking member.
- the inner periphery of the outer race 3 forms a circular cylindrical surface and recesses are formed in the outer periphery (roller receiving portions 26 ) of the inner race 2 to provide pockets PK; however, the outer periphery of the inner race 2 may form a circular cylindrical surface and recesses may be formed in the outer race 3 to provide pockets PK.
- the rotation restricting portion 35 is provided on the outer race 3 ; however, the rotation restricting portion 35 may be provided on the inner race 2 .
- the unlocked state is achieved when the contacting portion 63 is in contact with the large diameter portion 52
- the lockable state is achieved when the contacting portion is in contact with the small diameter portion 51
- the lockable state may be achieved when the contacting portion 63 is in contact with the large diameter portion 52
- the unlocked state may be achieved when the contacting portion is in contact with the small diameter portion 51
- the circumferential surface of the unlocking member 4 to which the contacting portion 63 contacts may be the inner peripheral surface instead of the outer peripheral surface. In this instance, the return engagement portion 53 protrudes inward.
- the switching member 5 is configured to be rotatable in conjunction with the outer race 3 ; however, the switching member 5 may be rotatable in conjunction with the inner race 2 .
- the return engagement portion 53 is provided at the connecting portion between the small diameter portion 51 and the large diameter portion 52 ; however, the return engagement portion 53 may be provided on the large diameter portion 52 or on the small diameter portion 51 .
- the spring 72 is exemplified as an example of the urging member; however, the urging member may be a rubber damper.
- the one-way clutch 1 is exemplified as an example of the clutch; however, the clutch may be a two-way clutch which is engageable (lockable) when the inner race and the outer race rotate in any directions.
- a movable piece (roller 71 ), a pocket PK, an unlocking piece 41 and the like may be provided symmetrically with respect to the spring 72 .
- the one-way clutch is exemplified to support the armrest.
- the use of the one-way clutch is not limited to this specific configuration.
- the one-way clutch according to the present invention is applicable to a movable lumbar support, a height adjustment mechanism of a seat, a tilt-angle adjustable headrest which is rotatable in forward and rearward directions, and a movable ottoman (footrest).
- the switching member 5 is configured to be rotatable relative to the outer race 3 ; however, the switching member may be configured not to be relatively rotatable (e.g., rotatable together) with respect to the outer race.
- the return engagement portion 53 is not provided (may be provided though it is not necessary) anywhere on the whole outer peripheral surface (whole range of 360 degrees) of the switching member, part of which may be formed as the large diameter portion 52 and the rest of which may be formed as the small diameter portion.
- a rotating member corresponding to the arm frame R 1 can rotate freely in a range where the contacting portion 63 is in contact with the large diameter portion 52 , and rotate only in one direction in a range where the contacting portion 63 is in contact with the small diameter portion 51 .
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Abstract
An armrest attachable to a seat back includes: an arm frame; and a clutch through which the arm frame is rotatably supported by the seat back. The clutch includes: an inner member (inner race) configured to be fixed to one of the arm frame and the seat back; an outer race provided radially outward of the inner member and spaced apart from the inner member, and configured to be fixed to the other one of the arm frame and the seat back; an unlocking member provided coaxially with the inner member and the outer race and configured to be rotatable relative to both of the inner member and the outer race; and an unlocking manipulation mechanism configured to actuate the unlocking member to unlock a locked state.
Description
- The present invention relates to an armrest, in particular to an armrest using a clutch which can be downsized in an axial direction.
- In some passenger cars, a seat may be provided with an armrest. As disclosed in
Patent Literature 1, a certain improved armrest is configured such that the rotation of the armrest in a downward direction is locked within an angle range of the armrest in a use state, but the armrest is allowed to rotate freely in upward and downward directions within the other angle range of the armrest in a non-use state. - The armrest disclosed in
Patent Literature 1 employs as a one-way clutch mechanism for locking the rotation of the armrest in the downward direction a structure including a shaft and a coil spring wound around the outer periphery of the shaft. This configuration utilizes the characteristic of the coil spring such that when the rotation is made in the same direction as that in which the coil spring is wound up, the rotation of the coil spring with respect to the shaft is locked, but the rotation made in the reverse direction in which the coil spring is unlocked is allowed. - Patent Literature 1: Japanese Laid-open Patent Application, Publication No. 2009-261828
- However, a one-way clutch mechanism using a coil spring as disclosed in
Patent Literature 1 has a problem that the size of the coil spring in its axial direction is large. In a roller-type one-way clutch mechanism including rollers disposed between an inner race and an outer race, the size of the one-way clutch mechanism can be made relatively smaller in the axial direction; however, there is no known structure for unlocking the one-way clutch function in a predetermined angle range only by rotating the inner race or the outer race with a predetermined rotating action. - In view of the above-background, the present invention seeks to provide an armrest using a clutch which can be downsized in the axial direction.
- Further, the present invention also seeks to provide an armrest which can be reduced in weight. Further, the present invention seeks to provide an armrest in which a locally weakened portion would be unlikely to be produced even if the weight is reduced.
- Further, the present invention also seeks to provide an armrest in which the inner race or the outer race can be prevented from receiving an excessive radial load.
- Further, the present invention also seeks to provide an armrest of which the unlocking operation can be performed easily so that improvement in the easy operability can be achieved.
- Further, the present invention seeks to provide a one-way clutch, as a clutch used for an armrest, which one-way clutch can be downsized in the axial direction and can allow the inner race and the outer race to be disengaged by a predetermined operation, thereby making the inner race and the outer race rotatable relative to each other.
- Further, the present invention also seeks to provide a one-way clutch in which the inner race and the outer race can be prevented from receiving an excessive radial load.
- Further, the present invention also seeks to provide a one-way of which the unlocking operation can be performed easily so that improvement in the easy operability can be achieved.
- Further, another object of the present invention is to reduce the weight of each of the constituting elements for the one-way clutch as well as to improve the rigidity of these constituting elements. Further, the present invention seeks to provide a one-way clutch which can allow each of the constituting elements for the one-way clutch to be manufactured easily as well as to reduce the number of the constituent parts.
- In order to solve the above-described problem, an armrest according to the present invention is an armrest attachable to a seat back, comprising: an arm frame; and a clutch through which the arm frame is rotatably supported by the seat back, wherein the clutch comprises: an inner member configured to be fixed to one of the arm frame and the seat back; an outer race provided radially outward of the inner member and spaced apart from the inner member, and configured to be fixed to the other one of the arm frame and the seat back; an unlocking member provided coaxially with the inner member and the outer race, and configured to be rotatable relative to both of the inner member and the outer race; and an unlocking manipulation mechanism configured to actuate the unlocking member to unlock a locked state.
- With this configuration of the armrest, since a shaft and a coil spring are not used, the size in the axial direction can be reduced.
- In the above-described armrest, the inner member may be an inner race; and the armrest may comprise a movable piece received in a pocket which is located between the inner race and the outer race and includes a portion whose radial width decreases with distance toward one circumferential direction; the unlocking member may have an unlocking piece arranged adjacent to one side of the movable piece in the one circumferential direction; and the unlocking manipulation mechanism may be configured to actuate the unlocking member to unlock the locked state in which the movable piece is trapped by inner walls of the pocket.
- With this configuration of the armrest, the movable piece received in the pocket enables locking without using a shaft and a coil spring, and the unlocking member and the unlocking manipulation mechanism can unlock the locked state. Accordingly, the size in the axial direction can be reduced.
- In the above-described armrest, the clutch may be a one-way clutch; and the unlocking manipulation mechanism may include a first manipulation member configured to be engaged with or fixed to the unlocking member, and a switching member configured to be coaxial with and rotatable relative to both of the inner race and the outer race and having a circumferential surface; the first manipulation member may contact the circumferential surface of the switching member, and the circumferential surface of the switching member may include a small diameter portion and a large diameter portion having a diameter greater than that of the small diameter portion; one of the inner race and the outer race may have a rotation restricting portion engageable with the switching member to restrict a relative rotation thereof with respect to the switching member in a predetermined angular range; the circumferential surface may be provided with a return engagement portion protruding radially from the circumferential surface, and when the first manipulation member is brought into contact with one of the small diameter portion and the large diameter portion, the unlocking member is allowed to rotate in the one circumferential direction to cause the movable piece to be trapped and thus locked by the inner walls of the pocket, whereas when the first manipulation member is brought into contact with the other one of the small diameter portion and the large diameter portion, the unlocking member is allowed to rotate in the other circumferential direction to unlock the locked state of the movable piece.
- With this configuration, when one of the inner race and the outer race is rotated with respect to the other one of them, the switching member relatively rotates with respect to the first manipulation member in conjunction with the rotation of the one of the inner race and the outer race. For this reason, if one of the inner race and the outer race is rotated, a contacting point of the first manipulation member which contacts the circumferential surface of the switching member is switched between the large diameter portion and the small diameter portion in accordance with the phase (direction) of the switching member. Since the first manipulation member is engaged with or fixed to the unlocking member, the unlocking member slightly rotates in a circumferential direction. This can cause the unlocking piece of the unlocking member to rotate in one circumferential direction or in the other circumferential direction. In the case of rotation in the one circumferential direction (i.e., direction in which the radial width of the pocket decreases), the movable piece is trapped and thus locked in the pocket. Namely, the inner race and the outer race are engaged with each other so that they are not rotatable relative to each other. On the other hand, when the unlocking member is rotated in the other circumferential direction, the unlocking piece pushes the movable piece toward the direction in which the radial width of the pocket becomes larger to unlock the locked state. In other words, the inner race and the outer race become freely rotatable relative to each other.
- As described above, according to the present invention, the armrest including the movable piece in the pocket can perform locking and locking operations by rotating the armrest.
- Further, the inner race having the rotation restricting portion or the outer race having the rotation restricting portion can be freely rotatable relative to the switching member in the range where the rotation restricting portion does not restrict the relative rotation with respect to the switching member. On the other hand, in the range where the rotation is restricted, the inner race having the rotation restricting portion or the outer race having the rotation restricting portion rotates together with the switching member. When the switching member and one of the inner race and the outer race rotate together, the switching member and the first manipulation member rotate relatively to each other, so that the contacting point of the first manipulation member which contacts the circumferential surface of the switching member is switched between the small diameter portion and the large diameter portion. In this configuration, since the circumferential surface is provided with the return engagement portion protruding radially outward from the circumferential surface, for example, the first manipulation member, which is in contact with the large diameter portion after rotating one of the inner race and the outer race to ride over the return engagement portion, can engage with the return engagement portion by the reverse rotation of one of the inner race and the outer race and cause the switching member to rotate in the reverse direction. Namely, since not only is the switching member rotatable relative to the inner race or the outer race in one direction but also rotatable in the reverse direction, one of the inner race and the outer race can be moved back and forth relative to the other one of them. In the back and forth motions, the locked state and the unlocked state of the inner race and the outer race can be switched over in accordance with whether the first manipulation member contacts with the large diameter portion or the small diameter portion, both of which are provided on the circumferential surface of the switching member.
- The expression “the switching member relatively rotates with respect to the first manipulation member” includes the case where, as viewed from outside, the first manipulation member is rotatable while the switching member is stationary. This is because, in this example too, the switching member rotates relatively with respect to the first manipulation member.
- In the above-described armrest, the inner race may comprise a first metal part constituting a part of the inner walls of the pocket, and a first resin part; and a rugged portion formed on an inner periphery of the first metal part and a rugged portion formed on an outer periphery of the first resin part may be engaged with each other such that the first metal part and the first resin part are assembled together to prevent relative slippage in circumferential directions.
- With this configuration, weight reduction can be achieved by using the first resin part while the strength required for the inner race is provided by the first metal part.
- Further, the above-described armrest may further comprise an urging member arranged to urge the movable piece toward the one circumferential direction, and the inner race may comprise a first metal part constituting a part of the inner walls of the pocket, and a first resin part; a rugged portion formed on an inner periphery of the first metal part and a rugged portion formed on an outer periphery of the first resin part may be engaged with each other such that the first metal part and the first resin part are assembled together to prevent relative slippage in circumferential directions; at the outer periphery of the first metal part, the first metal part may have an urging member receiving recess which is recessed toward a center of the first metal part to receive the urging member; and the rugged portion of the first metal part may have a protrusive portion protruding toward the center of the first metal part, and the protrusive portion may be arranged radially inward of the urging member receiving recess.
- With this configuration, weight reduction can be achieved by using the first resin part while the strength required for the inner race is provided by the first metal part, and further the radial width of the first metal part is increased to avoid the presence of a locally weakened portion that would occur at the first metal part.
- In the above-described armrest, the outer race may comprise a second metal part constituting a part of the inner walls of the pocket, and a second resin part, and a rugged portion formed on an outer periphery of the second metal part and a rugged portion formed on an inner periphery of the second resin part may be engaged with each other such that the second metal part and the second resin part are assembled together to prevent relative slippage in circumferential directions.
- With this configuration, weight reduction can be achieved by using the second metal part while the strength required for the outer race is provided by the second metal part.
- In the above-described armrest, it is preferable that the rugged portion of the second metal part has a protrusive portion protruding radially outward, and when the clutch is in the locked state, the protrusive portion is positioned radially outward of the movable piece.
- According to this configuration, the contact pressure of the movable piece can be received by a high rigidity portion of the second metal part, which can ensure the strength of the second metal part.
- In the above-described armrest, it is preferable that the unlocking member has an extension portion extending radially outward, and that the first manipulation member engages with the unlocking member at the extension portion, and the first manipulation member is arranged radially outward of the outer race in a region where the first manipulation member and the outer race overlap in an axial direction.
- With this configuration, since the first manipulation member is arranged radially outward of the outer race in a region where the first manipulation member and the outer race overlap in the axial direction, the size in the axial direction is less likely to increase even if the first manipulation member is provided. In other words, the size in the axial direction can be reduced.
- In the above-described armrest, it is preferable that the inner walls of the pocket have a projection at one side of the movable piece in the one circumferential direction, and when the inner race and the outer race are forcibly and relatively rotated in a locking direction, the projection contacts the movable piece.
- With this configuration, when the inner race and the outer race are forcibly rotated in the locking direction, the projection and the movable piece are brought into contact so that the movable piece is not strongly trapped by the er wall the inner walls the pocket any more. This can prevent the inner race or the outer race from receiving an excessive radial load.
- In the above-described armrest, the unlocking manipulation mechanism may be engaged with or fixed to the unlocking member and include a second manipulation member extending toward a distal end of the arm frame, and when the second manipulation member is manipulated to rotate the unlocking member in the other circumferential direction, the movable piece may be allowed to be unlocked.
- With this configuration, not only can locking and unlocking be performed by the predetermined relative rotation of the inner race and the outer race but also the unlocking can be performed by the manipulation of the second manipulation member. This can improve the easy operability.
- In the above-described armrest, it is preferable that: the unlocking manipulation mechanism is engaged with or fixed to the unlocking member and includes a second manipulation member extending toward a distal end of the arm frame; that when the second manipulation member is manipulated to rotate the unlocking member in the other circumferential direction, the movable piece is allowed to be unlocked: that the first manipulation member is provided arcuately around an axis of rotation of the arm frame, and the second manipulation member is provided along a longitudinal direction of the arm flame; and that the first manipulation member and the second manipulation member are arranged so as not to overlap each other as viewed from an axial direction.
- According to this configuration, since the first manipulation member and the second manipulation member are arranged so as not to overlap each other as viewed from the axis of rotation of the arm rest, the size in the axial direction is less likely to increase even if the first manipulation member and the second manipulation member are provided.
- In the above-described armrest, it is preferable that the small diameter portion and the large diameter portion are formed as flanges extending from a peripheral edge of the switching member in an axial direction of the switching member.
- With this configuration, while the weight of the switching member can be reduced, it is possible to enlarge the sliding contact surface contacting with the contacting portion.
- In this armrest, it is preferable that the flange constituting the small diameter portion and the flange constituting the large diameter portion are connected to each other. This can improve the rigidity of the switching member.
- Further, in the above-described armrest, it is preferable that the return engagement portion is integrally molded with the switching member. This can ease the manufacture of the return engagement portion, and the number of the constituent parts can be reduced.
- Further, in the above-described armrest, it is preferable that the extension portion is integrally molded with the unlocking member. This can ease the manufacture of the extension portion, and the number of the constituent parts can be reduced.
- In the above-described armrest, it is preferable that: a first attachment member is fixed to the inner race and a second attachment member is fixed to the outer race; that one of the first attachment member and the second attachment member has a stopper which protrudes toward the one-way clutch and is engageable with the inner race or the outer race fixed to the other one of the first attachment member and the second attachment member to restrict a rotation range of the one of the first attachment member and the second attachment member; and that the stopper is arranged in a region where the stopper and the extension portion overlap in the axial direction and where the stopper and the extension portion do not overlap as viewed from the axial direction.
- According to this configuration, since the extension portion and the stopper are arranged in a region where they do not overlap each other as viewed from the axial direction and where they overlap in the axial direction, the size of the armrest can be further reduced in the axial direction.
- Further, a clutch used for the above-described armrest comprises: an inner race; an outer race provided radially outward of the inner race and spaced apart from the inner race; a movable piece received in a pocket which is located between the inner race and the outer race and includes a portion whose radial width decreases with distance toward one circumferential direction; an unlocking member provided coaxial with the inner race and the outer race and configured to be rotatable relative to both of the inner race and the outer race: a first manipulation member configured to be engaged with or fixed to the unlocking member; and a switching member configured to be relatively rotatable with respect to the first manipulation member in conjunction with rotation of one of the inner race and the outer race and having a circumferential surface, wherein the unlocking member has an unlocking piece arranged adjacent to one side of the movable piece in the one circumferential direction, wherein the first manipulation member contacts the circumferential surface of the switching member, and the circumferential surface of the switching member includes a small diameter portion and a large diameter portion having a diameter greater than that of the small diameter portion, and wherein when the first manipulation member is brought into contact with one of the small diameter portion and the large diameter portion, the unlocking member is allowed to rotate in the one circumferential direction to cause the movable piece to be trapped and thus locked in the pocket, whereas when the first manipulation member is brought into contact with the other one of the small diameter portion and the large diameter portion, the unlocking member is allowed to rotate in the other circumferential direction to unlock the locked state of the movable piece.
- With this configuration, when one of the inner race and the outer race is rotated with respect to the other one of them, the switching member relatively rotates with respect to the first manipulation member in conjunction with the rotation of the one of the inner race and the outer race. For this reason, if one of the inner race and the outer race is rotated, a contacting point of the first manipulation member which contacts the circumferential surface of the switching member is switched between the large diameter portion and the small diameter portion in accordance with the phase (direction) of the switching member. Since the first manipulation member is engaged with or fixed to the unlocking member, the unlocking member slightly rotates in a circumferential direction. This can cause the unlocking piece of the unlocking member to rotate in one circumferential direction or in the other circumferential direction. In the case of rotation in the one circumferential direction (i.e., direction in which the radial width of the pocket decreases), the movable piece is trapped and thus locked in the pocket. Namely, the inner race and the outer race are engaged with each other so that they are not rotatable relative to each other. On the other hand, when the unlocking member is rotated in the other circumferential direction, the unlocking piece pushes the movable piece toward the direction in which the radial width of the pocket becomes larger to unlock the locked state. In other words, the inner race and the outer race become freely rotatable relative to each other.
- As described above, according to the present invention, the one-way clutch including the movable piece provided in the pocket can perform locking and locking operations by rotating one of the inner race and the outer race. Namely, the size of the one-way clutch can be reduced in the axial direction, and the one-way clutch can allow the engagement between the inner race and the outer race to be disengaged by a predetermined operation, thereby slipping the inner race and the outer race relative to each other.
- The expression “the switching member relatively rotates with respect to the first manipulation member” includes the case where, as viewed from outside, the first manipulation member is rotatable while the switching member is stationary. This is because, in this example too, the switching member rotates relatively with respect to the first manipulation member.
- In the above-described one-way clutch, the switching member may be configured to be rotatable relative to both of the inner race and the outer race, and one of the inner race and the outer race may have a rotation restricting portion engageable with the switching member to restrict a relative rotation thereof with respect to the switching member in a predetermined angular range, and further the circumferential surface may be provided with a return engagement portion protruding radially outward from the circumferential surface.
- With this configuration, the inner race having the rotation restricting portion or the outer race having the rotation restricting portion can be freely rotatable relative to the switching member in the range where the rotation restricting portion does not restrict the relative rotation with respect to the switching member. On the other hand, in the range where the rotation is restricted the inner race having the rotation restricting portion or the outer race having the rotation restricting portion can rotate together with the switching member. When the switching member and one of the inner race and the outer race rotate together, the switching member and the first manipulation member rotate relatively to each other, so that the contacting point of the first manipulation member which contacts the circumferential surface of the switching member is switched between the large diameter portion and the large diameter portion. In this configuration, since the circumferential surface is provided with the return engagement portion protruding radially outward from the circumferential surface, for example, the first manipulation member, which is in contact with the large diameter portion after rotating one of the inner race and the outer race to ride over the return engagement portion, can engage with the return engagement portion by the reverse rotation of one of the inner race and the outer race and cause the switching member to rotate in the reverse direction. Namely, since not only is the switching member rotatable relative to the inner race or the outer race in one direction but also rotatable in the reverse direction, one of the inner race and the outer race can be moved back and forth relative to the other one of them. In the back and forth motions, the locked state and the unlocked state of the inner race and the outer race can be switched in accordance with whether the first manipulation member contacts with the large diameter portion or the small diameter portion, both of which are provided on the circumferential surface of the switching member.
- In the above-described one-way clutch, it is preferable that the unlocking member has an extension portion extending radially outward, and that the first manipulation member engages with the unlocking member at the extension portion, and the first manipulation member is arranged radially outward of the outer race in a region where the first manipulation member and the outer race overlap in an axial direction.
- With this configuration, since the first manipulation member is arranged radially outward of the outer race in a region where the first manipulation member and the outer race overlap in the axial direction, the size in the axial direction is less likely to increase even if the first manipulation member is provided. In other words, the size in the axial direction can be reduced.
- In the above-described one-way clutch, it is preferable that the inner walls of the pocket have a projection at one side of the movable piece in the one circumferential direction, and when the inner race and the outer race are forcibly and relatively rotated in a locking direction, the projection contacts the movable piece.
- With this configuration, when the inner race and the outer race are forcibly rotated in the locking direction, the projection and the movable piece are brought into contact so that the movable piece is not strongly trapped by the inner walls of the pocket any more. This can prevent the inner race or the outer race from receiving an excessive radial load.
- The above-described one-way clutch may further comprise a second manipulation member engaged with or fixed to the unlocking member, and it is preferable that when the second manipulation member is manipulated to rotate the unlocking member in the other circumferential direction, the inner race and the outer race are allowed to be unlocked.
- With this configuration, not only can locking and unlocking be performed by the predetermined relative rotation of the inner race and the outer race but also the unlocking can be performed by the manipulation of the second manipulation member. This can improve the easy operability.
- In the above-described one-way clutch, it is preferable that the small diameter portion and the large diameter portion are formed as flanges extending from a peripheral edge of the switching member in an axial direction of the switching member.
- With this configuration while the weight of the switching member can be reduced, it is possible to enlarge the sliding contact surface contacting with the contacting portion.
- In this one-way clutch, it is preferable that the flange constituting the small diameter portion and the flange constituting the large diameter portion are connected to each other. This can improve the rigidity of the switching member.
- Further, in the above-described one-way clutch, it is preferable that the return engagement portion is integrally molded with the switching member. This can ease the manufacture of the return engagement portion, and the number of the constituent parts can be reduced.
- Further, in the above-described one-way clutch, it is preferable that the extension portion is integrally molded with the unlocking member. This can ease the manufacture of the extension portion, and the number of the constituent parts can be reduced.
- In the above-described one-way clutch, it is preferable that: a first attachment member is fixed to the inner race and a second attachment member is fixed to the outer race: that one of the first attachment member and the second attachment member has a stopper which protrudes toward the one-way clutch and is engageable with the inner race or the outer race fixed to the other one of the first attachment member and the second attachment member to restrict a rotation range of the one of the first attachment member and the second attachment member; and that the stopper is arranged in a region where the stopper and the extension portion overlap in the axial direction and where the stopper and the extension portion do not overlap as viewed from the axial direction.
- According to this configuration, since the extension portion and the stopper are arranged in a region where they do not overlap each other as viewed from the axial direction and where they overlap in the axial direction, the size of the one-way clutch can be further reduced in the axial direction.
-
FIG. 1 is a perspective view of a seat with an armrest. -
FIG. 2 shows left-side views explaining the motion of the armrest, in which (a) shows a stowing operation, and (b) shows a folding out operation. -
FIG. 3 is an exploded perspective view of the armrest. -
FIG. 4 includes (a) a right-side view of an outer race, and (b) a cross-sectional view taken along the line IV-IV of (a). -
FIG. 5 is a view showing the inner structure of a one-way clutch. -
FIG. 6 shows views explaining the motion of a roller, in which (a) shows rotation in an unlocking direction, (b) shows rotation in a locking direction, and (c) shows the roller in an unlocked state. -
FIG. 7 includes view of the one-way clutch observed when the armrest is in a fold out position (position A), in which (a) shows a left-side view of the one-way clutch, and (b) shows a view of the one-way clutch as seen from below. -
FIG. 8 is a left-side view of the one-way clutch in a locked state when the armrest is located near the position B. -
FIG. 9 is a left-side view of the one-way clutch in an unlocked state when the armrest is located near the position B. -
FIG. 10 is a left-side view of the one-way clutch in an unlocked state when the armrest is in a stowed position (position C). -
FIG. 11 is a left-side view of the one-way clutch in the unlocked state when the armrest is rotated from the stowed position toward the fold out position and is located near the position A. -
FIG. 12 is an enlarged view showing the structure around the roller of the one-way clutch according to a modified embodiment. - Hereinafter, a description will be given of one embodiment of an armrest as a movable member according to the present invention. As seen in
FIG. 1 , a seat S includes a seat back S1 and a seat bottom S2, and an armrest (first attachment member) R is fixed to the seat back (second attachment member) S1 through a one-way clutch 1 which is an example of a clutch. The following description will be given of the case in which, the armrest R provided at the right side of the seat back S1 as shown inFIG. 1 is seen from the left side. In this specification, directions of front, rear, right, left, upper and lower are designated as from the view point of an occupant sitting on the seat S, and for example, a view of the armrest R as seen from left (e.g.,FIG. 2 ) is referred to as a left-side view of the armrest R for convenience. - As seen in
FIGS. 2 (a) and (b), the armrest R is rotatable between a fold out state (position A) in which the distal end of the armrest faces frontward and a stowed state (position C) in which the distal end of the armrest faces upward. As seen inFIG. 2 (a), during the stowing operation for moving the armrest in a predetermined angle range from the fold out state toward the stowed state (in a range from the position A to the position B), the armrest R is allowed to rotate upward but is not allowed to rotate downward. The state in which the armrest is not allowed to rotate downward is referred to as being “locked” (locked state) in this specification. In contrast, during the stowing operation, the armrest R is allowed to rotate both upward and downward in a range from the position B to the position C. This state is referred to as being unlocked (unlocked state). Further, as seen inFIG. 2 (b), the armrest R is allowed to rotate both upward and downward during the folding out operation for moving the armrest R from the stowed position (position C) toward the fold out position (position A). In other words, the armrest R is in the unlocked state. - In the folding out operation, when the armrest R is completely rotated to the position A, it returns to the locked state. However, independent of the above operation, the armrest R can be unlocked in any posture by depressing a lower portion of a manipulation lever R2 provided at the distal end of the armrest R.
- The configuration for performing the above-described function of the armrest R will be described below.
- As seen in
FIG. 3 , the armrest R includes an arm frame R1 made of plastic resin; although not shown in the drawings, a cushion and a skin are provided outside the arm frame R1. The arm frame R1 has a shape extending in the front-rear direction ofFIG. 3 , and the rear end portion of the arm frame R1 is rotatably attached to the seat back S1 through the one-way clutch 1 using a bolt (not shown) or the like. At the rear end portion of the arm frame R1, aninner race 2B made of plastic resin, which is an example of a first resinous member, is formed on the left side. Provided on the outer periphery of the plasticinner race 2B is a rugged shaped portion (rugged portion) 21B having different outer diameters arranged at a constant pitch. - Provided radially outward of the plastic
inner race 2B are stoppers R4 protruding leftward (toward the one-way clutch 1) at two opposite positions across the plasticinner race 2B. The stoppers R4 are engageable withstoppers 38 of an outer race 3 (one of theinner race 2 and theouter race 3 fixed to the seat back S1) to be described later in a circumferential direction, to thereby restrict a relative rotation range of theouter race 3 and the arm frame R1. - The one-
way clutch 1 includes theinner race 2, theouter race 3,rollers 71 as an example movable pieces, and springs 72 as an example of urging members. The one-way clutch 1 further includes, as an unlocking manipulation mechanism for unlocking a locked state in which eachroller 71 is trapped by the inner walls of a pocket PK, an unlockingmember 4, a switchingmember 5, and amanipulation rod 6. - The
inner race 2 consists of aninner race 2A made of metal which is an example of a first metal part, and the plasticinner race 2B as described above. The metalinner race 2A has a rugged shaped portion (rugged portion) 21A at the inner periphery of a center through-hole thereof, and the rugged shapedportion 21B of the plasticinner race 2B and the rugged shapedportion 21A of the metalinner race 2A are engaged with each other such that the metalinner race 2A and the plasticinner race 2B are assembled together to prevent relative slippage in circumferential directions. Accordingly, theinner race 2 is fixed to the arm frame R1. Further, since theinner race 2 is made by assembling the metalinner race 2A and the plasticinner race 2B together, weight reduction can be achieved while ensuring the required strength. - As seen in
FIG. 5 , the metalinner race 2A has threeroller receiving portions 26 equiangularly arranged and protruding radially outward. The outer peripheral surface of eachroller receiving portion 26 is provided with a recess which is recessed toward a center of the metalinner race 2A, and the recess includes a slantedsurface 22 whose radius gradually increases with distance in the clockwise direction ofFIG. 5 (hereinafter, clockwise and anticlockwise directions are referred to based on the directions ofFIG. 5 ), and an urgingmember receiving recess 23 which is adjacent to one end of the slantedsurface 22 in the anticlockwise direction and recessed toward the center beyond the slantedsurface 22. Astopper portion 24 for regulating the positional relation between an unlockingpiece 41 to be described later and the metalinner race 2A is provided at an end of the slantedsurface 22 in the clockwise direction. Further, arestriction wall 25 for restricting posture of aspring 72 is provided at one side of the urgingmember receiving recess 23 in the anticlockwise direction. - It should be noted that the rugged shaped
portion 21A at the inner periphery of the metalinner race 2A has protrusive portions (portions protruding radially inward; seereference numeral 21X ofFIG. 5 ), and the protrusive portions are arranged radially inward of the urging member receiving recesses 23. This can increase the radial width of the metalinner race 2A to avoid the presence of locally weakened portions that would occur at the metalinner race 2A. - The
outer race 3 is provided radially outward of the inner race 2 (metalinner race 2A) and spaced apart from theinner race 2. Theinner periphery 31 of theouter race 3 forms a circular cylindrical surface, and pockets PK each receiving aroller 71 and aspring 72 are formed between theslanted surface 22 of the metalinner race 2A and theinner periphery 31 of theouter race 3. Since the radius along the slantedsurface 22 decreases with distance toward the clockwise direction while theinner periphery 31 of theouter race 3 has the circular cylindrical surface, each pocket PK includes a portion whose radial width decreases with distance toward one circumferential direction (i.e., clockwise direction). - Each unlocking
piece 41 is arranged in the pocket PK adjacent to one side of theroller 71 in the one circumferential direction (i.e., clockwise direction side). The unlockingmember 4 has the unlockingpieces 41. Aspring 72 made of a substantially U-shaped leaf spring is arranged adjacent to the other side of theroller 71 in the one circumferential direction (i.e., anticlockwise direction side). As shown in an enlarged view inFIG. 6 (a), thespring 72 is received at itsbent portion 72A in the urgingmember receiving recess 23 such that onearm 72B abuts on therestriction wall 25 and theother arm 72C urges theroller 71 in the clockwise direction. By this urging force theroller 71 is brought into contact with the inner walls (i.e., the slantedsurface 22 and the inner periphery 31) of the pocket PK to thereby prevent backlash. It should be noted that the urging force of thespring 72 is so weak as necessary and sufficient to prevent the backlash of theroller 71, but not so strong that theroller 71 gets trapped in the inner walls of the pocket PK to lock the relative rotation between theinner race 2 and theouter race 3. - As seen in
FIGS. 4 (a) and (b), theouter race 3 consists of a metalouter race 3A as an example of a second metal member and a plasticouter race 3B as an example of a second resin member. - As described above, the metal
outer race 3A has aninner periphery 31 in the form of a circular cylindrical surface, and an outer periphery thereof has a rugged shaped portion (rugged portion) 32A having different outer diameters arranged at a constant pitch. The plasticouter race 3B has an inner surface provided with a rugged shapedportion 32B corresponding to the rugged shapedportion 32A, and the rugged shapedportion 32A of the metalouter race 3A and the rugged shapedportion 32B of the plasticouter race 3B are engaged with each other such that the metalouter race 3A and the plasticouter race 3B are assembled together to prevent relative slippage in circumferential directions. Accordingly, since theouter race 3 is made by assembling the metalouter race 3A and the plasticouter race 3B, weight reduction can be achieved while ensuring the required strength. When the one-way clutch 1 is in a lockable state, that is in a range from the position A to the position B during the stowing operation of the armrest R as shown inFIG. 2 (a), it is preferable that protrusive portions (portions protruding radially outward) of therugged portion 32A formed on the outer periphery of the metalouter race 3A are arranged radially outward of therollers 71. According to this configuration, the contact pressures of therollers 71 can be received by high rigidity portions of the metalouter race 3A, which can ensure the strength of the metalouter race 3A. - As seen in
FIG. 3 , acircular support shaft 34 protrudes outward at the left-side surface of the plasticouter race 3B. Further,protrusions 39 are provided on thesupport shaft 34; theprotrusions 39 are engageable with the seat back S1 to prevent the rotation of theouter race 3 relative to the seat back S1. Twostoppers 38 protruding radially outward (seeFIG. 4 (a)) are provided on the outer periphery of the plasticouter race 3B. Further, arotation restricting portion 35 is provided at an outer edge portion of the right-side surface of the plasticouter race 3; therotation restricting portion 35 protrudes outward to restrict a relative rotation of theouter race 3B with respect to the switchingmember 5 in a predetermined angular range. - The unlocking
member 4 is configured to unlock the locked state in which eachroller 71 is trapped by the inner walls of the corresponding pocket PK. As seen inFIG. 3 , the unlockingmember 4 is made of a plate-like ring member, and has anextension portion 42 extending radially outward (e.g., lower direction inFIG. 3 ). Theextension portion 42 is integrally molded with the main body of the unlockingmember 4 and thus can be easily manufactured and the number of constituent parts can be reduced. The unlockingmember 4 is configured such that theextension portion 42 is positioned between the two stoppers R4 when it is assembled with the plasticinner race 21B. To be more specific, theextension portion 42 is provided in a region where theextension portion 42 and the stoppers R4 overlap in the axial direction and where theextension portion 42 and the stoppers R4 do not overlap as viewed from the axial direction as shown inFIG. 7 (a) andFIGS. 8-10 . Accordingly, the one-way clutch 1 (armrest R) can be downsized in the axial direction by effectively utilizing the space. - The
extension portion 42 is provided with anengagement projection 43 with which themanipulation rod 6 is engaged. An innerperipheral portion 44 of the unlockingmember 4 has a diameter corresponding to the outer diameter of the plasticinner race 2B, so that when the innerperipheral portion 44 is fitted onto the plasticinner race 2B, the unlockingmember 4 is coaxial with theinner race 2 and rotatable relative to theinner race 2. Further, since theinner race 2 and theouter race 3 are rotatable relative to each other and they are not fixed to each other, the unlockingmember 4 is coaxial with theinner race 2 and theouter race 3 and rotatable relative to both of theinner race 2 and theouter race 3. - The unlocking
pieces 41 as described above are provided protrusively at the left-side surface of the unlockingmember 4 corresponding to each of therollers 71. - The switching
member 5 is configured to cooperate with themanipulation rod 6 to switch over between the locked state and the unlocked state of theinner race 2 and the outer race 3 (rollers 71) actuated by the rotating action of the armrest R. The switchingmember 5 is made by a plate-like ring member, and rotatable relative to theouter race 3 because the circular innerperipheral portion 54 is engaged with thesupport shaft 34 of theouter race 3.Restriction walls member 5 at a position obliquely frontward and downward and at a position downward, respectively, and as seen inFIG. 7 (a), when the switchingmember 5 is assembled with theouter race 3, therotation restricting portion 35 of theouter race 3 is located between therestriction wall 56 and therestriction wall 57. In other words, the switchingmember 5 and theouter race 3 are relatively rotatable in a range from where therotation restricting portion 35 contacts therestriction wall 56 to where therotation restricting portion 35 contacts therestriction wall 57. Further, since theouter race 3 and theinner race 2 are relatively rotatable, and the switchingmember 5 is not engaged with theinner race 2, the switchingmember 5 is rotatable relative to both of theinner race 2 and theouter race 3. It should be noted that while therotation restricting portion 35 is in contact with therestriction wall 56 or therestriction wall 57, theouter race 3 and the switchingmember 5 can rotate together in a corresponding rotating direction. - The switching
member 5 includes asmall diameter portion 51 of which the outer peripheral surface extends from rear side to upper side inFIG. 3 coaxially with the innerperipheral portion 54. Thesmall diameter portion 51 is formed with a flange extending from the peripheral edge of the switchingmember 5 in the axial direction (leftward). With this configuration, while the weight of the switchingmember 5 can be reduced, it is ensured to enlarge the sliding contact surface of the switchingmember 5 in contact with the contactingportion 63 of amanipulation rod 6 to be described later. Further, the switchingmember 5 includes alarge diameter portion 52 of which the outer peripheral surface extends from rear side to thelower restriction wall 57 inFIG. 3 coaxially with the innerperipheral portion 54 and which has a diameter slightly greater than that of thesmall diameter portion 51. As seen inFIG. 7 (b), like thesmall diameter portion 51, thelarge diameter portion 52 is formed with a flange extending from the peripheral edge of the switchingmember 5 in the axial direction (leftward), so that the sliding contact surface in contact with the contactingportion 63 of themanipulation rod 6 is ensured. The flange of thesmall diameter portion 51 and the flange of thelarge diameter portion 52 are connected to each other, so that the peripheral portion of the switchingmember 5 has high rigidity. - Provided on the circumferential surface of the switching
member 5 at the connecting portion between thesmall diameter portion 51 and thelarge diameter portion 52 is areturn engagement portion 53 protruding radially outward and shaped as a small peaked projection. Thereturn engagement portion 53 is integrally molded with the main body of the switchingmember 5 on the flange portions forming thesmall diameter portion 51 and thelarge diameter portion 52. With this configuration, thereturn engagement portion 53 can be easily manufactured and the number of constituent parts can be reduced. Further, therestriction wall 57 is adjacent to one end of thelarge diameter portion 52 in the clockwise direction and protrudes radially outward beyond thelarge diameter portion 52, so that when the contactingportion 63 slides on thelarge diameter portion 52, therestriction wall 57 restricts the sliding range of the contactingportion 63. - The
manipulation rod 6 is configured to cooperate with the switchingmember 5 to manipulate locking and unlocking of therollers 71 in accordance with the rotating action of the armrest R and the manipulation of the user. Themanipulation rod 6 is made of a metal rod having rigidity to allow a slight deformation thereof, and includes afirst manipulation portion 61 which is an example of a first manipulation member and extends in a circular arc shape, and asecond manipulation portion 62 which is an example of a second manipulation member and extends straight along the longitudinal direction of the arm frame R1 from the front end of thefirst manipulation portion 61 toward the distal end of the arm frame R1. In this embodiment, thefirst manipulation portion 61 and thesecond manipulation portion 62 are integrally formed, and they do not overlap as viewed from the axial direction of the armrest R. This can reduce the size of the armrest R in the axial direction. Further, since thesecond manipulation portion 62 is provided along the lower edge of the arm frame R1, and theextension portion 42 of the unlockingmember 4 extends downward, it is possible to prevent the armrest R from bulging upward as compared with the configuration in which thesecond manipulation portion 62 and theextension portion 42 are provided at the upper side of the arm frame R1. - An
engagement hole 69 is formed in a connecting portion which connects thefirst manipulation portion 61 and thesecond manipulation portion 62, and theengagement hole 69 is engaged with theengagement projection 43 provided on theextension portion 42 of the unlockingmember 4. Thefirst manipulation portion 61 is arranged radially outward of theouter race 3 in a position such that thefirst manipulation portion 61 and theouter race 3 overlap in the axial direction (seeFIG. 7 (b)). With this configuration, the size of the one-way clutch 1 does not increase in the axial direction even if thefirst manipulation portion 61 is provided. Accordingly, the one-way clutch can be downsized in the axial direction. Thefirst manipulation portion 61 extends arcuately from a portion with theengagement hole 69 along the outer periphery of theouter race 3, through 90 degrees from lower side to rear side ofFIG. 7 (a), and the contactingportion 63 formed by bending thefirst manipulation portion 61 leftward at the distal end thereof contacts the outer peripheral surface of the switching member 5 (e.g.,small diameter portion 51 in the example ofFIG. 7 (a)) from the radially outward side. Since the contactingportion 63 is provided by bending, the rigidity of the contactingportion 63 is enhanced. The position of the contactingportion 63 with respect to theengagement hole 69 is not limited to that in which it is separated by 90 degrees in phase about the center of rotation however, it is preferable that this position is separated away from the straight line connecting theengagement hole 69 and the center of thesmall diameter portion 51 and from the straight line connecting theengagement hole 69 and the center of thelarge diameter portion 52 as far as possible. Since thefirst manipulation portion 61 is engaged with the unlockingmember 4, and the unlockingmember 4 is relatively rotatable with respect to theouter race 3, the switchingmember 5 is relatively rotatable with respect to thefirst manipulation portion 61 in conjunction with theouter race 3. - As seen in
FIG. 3 , anattachment hole 65 is formed at the front end of thesecond manipulation portion 62. The manipulation lever R2 swingable around a shaft R3 is provided at the front end of the arm frame R1, and the front end of thesecond manipulation portion 62 is connected to the manipulation lever R2 at a portion thereof below the shaft R3 using theattachment hole 65 by ascrew 68. Accordingly, when the lower end portion of the manipulation lever R2 is depressed rearward, the unlockingmember 4 is caused to rotate in the anticlockwise direction ofFIG. 7 (a) through thesecond manipulation portion 62. - The
return engagement portion 53 protrudes from thesmall diameter portion 51 and thelarge diameter portion 52, and when the switchingmember 5 and therotation restricting portion 35 are not engaged with each other (i.e., when the rotation of the switchingmember 5 is not restricted by the engagement between therotation restricting portion 35 and therestriction wall 56 or by the engagement between therotation restricting portion 35 and the restriction wall 57), the switchingmember 5 can be rotated by the contactingportion 63 engaged with the switchingmember 5. Further, thereturn engagement portion 53 protrudes to such an extent that when the rotation of the switchingmember 5 is restricted by the engagement between therotation restricting portion 35 and therestriction wall 56 or by the engagement between therotation restricting portion 35 and therestriction wall 57, thefirst manipulation portion 61 is caused to deform to allow the contactingportion 63 to ride over thereturn engagement portion 53. - Operation of the armrest R using the one-
way clutch 1 configured as described above will be described. - With reference to
FIG. 6 , description will be given of the operation of the one-way mechanism implemented with therollers 71 and the pockets PK as well as the unlocking operation implemented with the unlockingpieces 41. As seen inFIG. 6 (a), when theinner race 2 is rotated clockwise relative to theouter race 3, the space in a pocket PK rotates clockwise relative to theouter race 3, whereby a narrow portion in the pocket PK moves in a direction away from theroller 71 as far as the relation between the space in the pocket PK and theroller 71 is concerned. When attention is focused on theroller 71, theroller 71 is relatively moved toward a wider portion of a wedge-shaped space formed by the inner walls (slantedsurface 22 and inner periphery 31) of the pocket PK; actually, theroller 71 does not move relatively in the pocket PK because thespring 72 urges theroller 71. Accordingly, the contact pressure between the inner walls of the pocket PK and theroller 71 does not increase, and hence theroller 71 is allowed to rotate anticlockwise inFIG. 6 (a) and theinner race 2 can be rotated relatively with respect to theouter race 3. The rotation in this direction is referred to as rotation in the unlocking direction. - On the contrary, with reference to
FIG. 6 (b), when theinner race 2 is rotated anticlockwise relative to theouter race 3, the space in the pocket PK rotates anticlockwise relative to theouter race 3, whereby the narrow portion in the pocket PK moves in a direction toward theroller 71 as far as the relation between the space in the pocket PK and theroller 71 is concerned. When attention is focused on theroller 71, theroller 71 is relatively moved toward a narrower portion of the wedge-shaped space formed by the inner walls (slantedsurface 22 and inner periphery 31) of the pocket PK. Accordingly, theroller 71 is trapped by the inner walls of the pocket PK and the contact pressure between the pocket PK and theroller 71 increases, which inhibits theroller 71 from rotating relative to theinner race 2 and theouter race 3. In other words, theinner race 2 and theouter race 3 are locked. - With reference to
FIG. 6 (c), when an unlockingpiece 41 is rotated anticlockwise relative to theinner race 2, the unlockingpiece 41 comes into contact with theroller 71 to thereby urge theroller 71 anticlockwise. This can cause theroller 71 to be moved relatively toward the wider portion of the wedge-shaped space formed by the inner walls (slantedsurface 22 and inner periphery 31) of the pocket PK, whereby theroller 71 is disengaged from the inner walls of the pocket PK. In this state, theinner race 2 is allowed to rotate freely both clockwise and anticlockwise relative to theouter race 3. In other words, theinner race 2 and theouter race 3 are unlocked. - As described above, when the unlocking
piece 41 is not urging theroller 71 as shown inFIGS. 6 (a) and (b), theinner race 2 and theouter race 3 become non-rotatable relative to each other depending on the rotating direction of theinner race 2 and theouter race 3, and hence they are in a lockable state. In contrast, in the case shown inFIG. 6 (c), theinner race 2 can rotate relative to the outer race in any directions while slipping in theouter race 3, and hence they are in an unlocked state. - Based on the locking and unlocking principles as described above, the armrest R operates as follows.
- As seen in
FIG. 7 (a), when the arm frame R1 (armrest R) is located in the lowermost position, namely, when the armrest R is located in the position A in advance of the stowing operation, therotation restricting portion 35 of theouter race 3 is located in a position between therestriction wall 56 and therestriction wall 57 and closer to therestriction wall 56, and the contactingportion 63 of themanipulation rod 6 is positioned on thesmall diameter portion 51 of theouter race 3 at a position closest to thelarge diameter portion 52 and adjacent to thereturn engagement portion 53. In this position, the unlockingpiece 41 is not in contact with theroller 71, and as described above with reference toFIGS. 6 (a) and 6 (b), theinner race 2 and theouter race 3 are in the lockable state depending on their rotating direction. It should be noted that since theouter race 3 is fixed to the seat back S1 as described above, theouter race 3 is stationary inFIG. 7 (a) andFIGS. 8-11 . - When the arm frame R1 is rotated upward from the state shown in
FIG. 7 (a), the contactingportion 63 engages with a stepped portion (returnengagement portion 53 in this embodiment) formed between thelarge diameter portion 52 and thesmall diameter portion 51, whereby the switchingmember 5 is caused to rotate clockwise relative to theouter race 3 as it is pushed by the contactingportion 63. As seen inFIG. 8 , this rotation is permitted until therestriction wall 57 is brought into contact with therotation restricting portion 35. In this rotation range (from position A to position B), the unlockingpiece 41 is not in contact with theroller 71 and is in the lockable state; namely, the arm frame R1 can be rotated upward while the downward rotation thereof is inhibited. It should be noted that since the arm frame R1 rotates together with theinner race 2, theinner race 2 is rotated relatively with respect to theouter race 3 when the arm frame R1 is rotated upward. - When the arm frame R1 is rotated further upward, the rotation of the switching
member 5 in the clockwise direction is inhibited as therestriction wall 57 is in contact with therotation restricting portion 35 of theouter race 3, and as seen inFIG. 9 , the contactingportion 63 rides over thereturn engagement portion 53 and comes into contact with thelarge diameter portion 52. During this time, the contactingportion 63 is pulled toward the lower right direction ofFIG. 9 and theengagement hole 69 is also pulled slightly toward the lower right direction with the result that the unlockingmember 4 is relatively rotated anticlockwise with respect to theinner race 2. In this instance, although thefirst manipulation portion 61 slightly deforms outward, the deformation amount of the first manipulation portion 61 (the moving distance of the contactingportion 63 in the radially outward direction if theengagement hole 69 is regarded as a stationary portion) is slightly smaller than the difference between the radius of thesmall diameter portion 51 and the radius of thelarge diameter portion 52, and the sum of the moving distance of the contactingportion 63 resulting from the deformation of thefirst manipulation portion 61 and the moving distance of the contactingportion 63 resulting from the rotation of the unlockingmember 4 substantially corresponds to the difference between the radius of thesmall diameter portion 51 and the radius of thelarge diameter portion 52. - When the unlocking
member 4 is relatively rotated anticlockwise with respect to theinner race 2, as described above with reference toFIG. 6 (c), each of the unlockingpieces 41 urges theroller 71 anticlockwise into the unlocked state. Namely, the inner race 2 (arm frame R1) can be rotated in any arbitrary directions relative to theouter race 3 while the contactingportion 63 is in contact with thelarge diameter portion 52. - When the arm frame R1 is rotated further upward, the rotation of the switching
member 5 in the clockwise direction is inhibited as therestriction wall 57 is in contact with therotation restricting portion 35 of theouter race 3, and the contactingportion 63 slides on thelarge diameter portion 52 while the arm frame R1 is being rotated relative to theouter race 3. As seen inFIG. 10 , this rotation is permitted until the stopper R4 of the arm frame R1 is brought into contact with thestopper 38 of theouter race 3. When the stopper R4 of the arm frame R1 comes into contact with thestopper 38 of theouter race 3, the arm frame R1 has been rotated in the position C. In the range from the position ofFIG. 9 to the position ofFIG. 10 , the arm frame R1 can be rotated arbitrarily in both upward and downward directions. - When the arm frame R1 is rotated downward during the folding out operation from the state shown in
FIG. 10 toward the use position, the contactingportion 63 slides on thelarge diameter portion 52 in the anticlockwise direction and then engages with thereturn engagement portion 53 to cause the switchingmember 5 to rotate anticlockwise. As seen inFIG. 11 , the switchingmember 5 rotates until therestriction wall 56 comes into contact with therotation restricting portion 35. It should be noted that if the friction between the contactingportion 63 and thelarge diameter portion 52 is larger than the friction between the switchingmember 5 and theouter race 3, the contactingportion 63 will not slide on thelarge diameter portion 52, but instead the first manipulation portion 61 (contacting portion 63) and the switchingmember 5 together rotate anticlockwise, and the contactingportion 63 may slide on thelarge diameter portion 52 in the anticlockwise direction after therestriction wall 56 comes into contact with therotation restricting portion 35; however, irrespective of the order of the motion of the contactingportion 63, the contactingportion 63 moves into the state as shown inFIG. 11 . In the state shown inFIGS. 10 to 11 , the contactingportion 63 is in contact with thelarge diameter portion 52, and theinner race 2 and theouter race 3 are in the unlocked state. Therefore, the arm rest R1 can be rotated freely in both upward and downward directions. It should be noted thatFIG. 11 shows a state in which the arm frame R1 is located slightly above the position A. - When the arm frame R1 is rotated downward from the state shown in
FIG. 11 , the rotation of the switchingmember 5 in the anticlockwise direction is inhibited as therestriction wall 56 is in contact with therotation restricting portion 35, and the contactingportion 63 rides over thereturn engagement portion 53 while thefirst manipulation portion 61 is being deformed and then comes into contact with thesmall diameter portion 51. The contactingportion 63 then returns to the state shown inFIG. 7 (a). During this time, that position which the contactingportion 63 contacts the outer peripheral surface of the switchingmember 5 is switched from thelarge diameter portion 52 to thesmall diameter portion 51, and in contrast to the change from the state shown inFIG. 8 to the state shown inFIG. 9 , the unlockingmember 4 slightly rotates clockwise relative to theinner race 2. This can cause each of the unlockingpieces 41 not to urge theroller 71, and as described above with reference toFIGS. 6 (a) and (b), theinner race 2 and theouter race 3 return to the lockable state. - As described above, according to the one-
way clutch 1 in this embodiment, the locked state and the unlocked state can be switched over by the predetermined rotating action of the armrest R (arm frame R1). Further, since the one-way clutch 1 is not of the type using a coil spring wound around a shaft as in the case of the conventional armrest, and is configured to userollers 71 received in wedge-shaped pockets PK, the size of the one-way clutch 1 can be reduced in the axial direction. - Further, as describe above, since the switching
member 5 is rotatable relative to both of theinner race 2 and theouter race 3, and the rotation range thereof is restricted by therotation restricting portion 35 and therestriction walls return engagement portion 53 is provided on the switchingmember 5, the arm frame R1 can be moved from up to down and from down to tip. - Further, in addition to the above motions, depressing the lower end portion of the manipulation lever R2 causes the unlocking
member 4 to rotate anticlockwise through thesecond manipulation portion 62. This can allow the user to unlock at any time irrespective of the orientation of the arm frame R1 and/or the position of the contactingportion 63 in contact with the switchingmember 5. In other words, the easy operability can be improved. - Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment and various changes and modifications may be made where necessary.
- For example, as seen in
FIG. 12 , al inner wall of a pocket PK may be provided with aprojection 22A at one side of theroller 71 in a direction where the radial width of the pocket PK decreases and adjacent to theroller 71. With this configuration, when theinner race 2 and theouter race 3 are forcibly and relatively rotated in the locking direction, theprojection 22A and theroller 71 are brought into contact so that the contact pressure between theroller 71 and the inner walls of the pocket PK does not increase any further. This can prevent theinner race 2 and theouter race 3 from receiving an excessive radial load. It should be noted that the projection may be provided on theinner periphery 31 of theouter race 3. - Further, three
roller receiving portions 26 are provided in the above embodiment; however, the number of theroller receiving portions 26 is not limited as long as one or more roller receiving portion are provided. For smooth rotation of theinner race 2 and theouter race 3, the moreroller receiving portions 26, at least three or more, are preferable. - In the above embodiment, the
inner race 2 is fixed to the arm frame R1 and theouter race 3 is fixed to the seat back S1; however, theouter race 3 may be fixed to the arm frame R1 and theinner race 2 may be fixed to the seat back S1 instead. In this instance, it is to be understood, of course, that the orientation of the wedge-shaped pocket PK may be changed where appropriate. - Locking and unlocking the
inner race 2 and theouter race 3 in accordance with the rotation of the unlockingmember 4 in either of the circumferential directions can be modified where necessary in consideration of the orientation of the wedge-shaped pockets PK. - In the above embodiment,
rollers 71 are exemplified as an example of movable pieces: however, the movable pieces may be balls. As long as the sliding property is properly set, block-shaped or wedge-shaped small pieces each of which does not roll over relative to theinner race 2 and theouter race 3 may be used. - The first manipulation member may not be engaged with the unlocking member but may be fixed thereto. Even in this configuration, if the rigidity of the first manipulation member is set to allow the contacting portion of the first manipulation member to deform to ride over from the small diameter portion to the large diameter portion, the switching between locking and unlocking can be made by the rotation of the unlocking member. Similarly, the second manipulation portion may be fixed to the unlocking member.
- In the above embodiment, the inner periphery of the
outer race 3 forms a circular cylindrical surface and recesses are formed in the outer periphery (roller receiving portions 26) of theinner race 2 to provide pockets PK; however, the outer periphery of theinner race 2 may form a circular cylindrical surface and recesses may be formed in theouter race 3 to provide pockets PK. - In the above embodiment, the
rotation restricting portion 35 is provided on theouter race 3; however, therotation restricting portion 35 may be provided on theinner race 2. - In the above embodiment, the unlocked state is achieved when the contacting
portion 63 is in contact with thelarge diameter portion 52, whereas the lockable state is achieved when the contacting portion is in contact with thesmall diameter portion 51; however, using the same principle of switching the locked state and the lockable state by the rotation of the unlockingmember 4, the lockable state may be achieved when the contactingportion 63 is in contact with thelarge diameter portion 52, whereas the unlocked state may be achieved when the contacting portion is in contact with thesmall diameter portion 51. Further, the circumferential surface of the unlockingmember 4 to which the contactingportion 63 contacts may be the inner peripheral surface instead of the outer peripheral surface. In this instance, thereturn engagement portion 53 protrudes inward. - In the above embodiment, the switching
member 5 is configured to be rotatable in conjunction with theouter race 3; however, the switchingmember 5 may be rotatable in conjunction with theinner race 2. - In the above embodiment, the
return engagement portion 53 is provided at the connecting portion between thesmall diameter portion 51 and thelarge diameter portion 52; however, thereturn engagement portion 53 may be provided on thelarge diameter portion 52 or on thesmall diameter portion 51. - In the above embodiment, the
spring 72 is exemplified as an example of the urging member; however, the urging member may be a rubber damper. - In the above embodiment, the one-
way clutch 1 is exemplified as an example of the clutch; however, the clutch may be a two-way clutch which is engageable (lockable) when the inner race and the outer race rotate in any directions. For example, a movable piece (roller 71), a pocket PK, an unlockingpiece 41 and the like may be provided symmetrically with respect to thespring 72. - In the above embodiment, the one-way clutch is exemplified to support the armrest. However, the use of the one-way clutch is not limited to this specific configuration. For example, the one-way clutch according to the present invention is applicable to a movable lumbar support, a height adjustment mechanism of a seat, a tilt-angle adjustable headrest which is rotatable in forward and rearward directions, and a movable ottoman (footrest). Further, in the above embodiment, the switching
member 5 is configured to be rotatable relative to theouter race 3; however, the switching member may be configured not to be relatively rotatable (e.g., rotatable together) with respect to the outer race. In this instance, thereturn engagement portion 53 is not provided (may be provided though it is not necessary) anywhere on the whole outer peripheral surface (whole range of 360 degrees) of the switching member, part of which may be formed as thelarge diameter portion 52 and the rest of which may be formed as the small diameter portion. With this configuration, a rotating member corresponding to the arm frame R1 can rotate freely in a range where the contactingportion 63 is in contact with thelarge diameter portion 52, and rotate only in one direction in a range where the contactingportion 63 is in contact with thesmall diameter portion 51.
Claims (16)
1. An armrest attachable to a seat back, comprising:
an arm frame; and
a clutch through which the arm frame is rotatably supported by the seat back,
wherein the clutch comprises:
an inner member configured to be fixed to one of the arm frame and the seat back;
an outer race provided radially outward of the inner member and spaced apart from the inner member, and configured to be fixed to the other one of the arm frame and the seat back;
an unlocking member provided coaxially with the inner member and the outer race, and configured to be rotatable relative to both of the inner member and the outer race; and
an unlocking manipulation mechanism configured to actuate the unlocking member to unlock a locked state.
2. The armrest according to claim 1 , wherein the inner member is an inner race, wherein the armrest comprises a movable piece received in a pocket which is located between the inner race and the outer race and includes a portion whose radial width decreases with distance toward one circumferential direction, wherein the unlocking member has an unlocking piece arranged adjacent to one side of the movable piece in the one circumferential direction, and wherein the unlocking manipulation mechanism is configured to actuate the unlocking member to unlock the locked state in which the movable piece is trapped by inner walls of the pocket.
3. The armrest according to claim 2 , wherein the clutch is a one-way clutch, and the unlocking manipulation mechanism includes a first manipulation member configured to be engaged with or fixed to the unlocking member, and a switching member configured to be coaxial with and rotatable relative to both of the inner race and the outer race and having a circumferential surface, wherein the first manipulation member contacts the circumferential surface of the switching member, and the circumferential surface of the switching member includes a small diameter portion and a large diameter portion having a diameter greater than that of the small diameter portion, wherein one of the inner race and the outer race has a rotation restricting portion engageable with the switching member to restrict a relative rotation thereof with respect to the switching member in a predetermined angular range, wherein the circumferential surface is provided with a return engagement portion protruding radially from the circumferential surface, and wherein when the first manipulation member is brought into contact with one of the small diameter portion and the large diameter portion, the unlocking member is allowed to rotate in the one circumferential direction to cause the movable piece to be trapped and thus locked by the inner walls of the pocket, whereas when the first manipulation member is brought into contact with the other one of the small diameter portion and the large diameter portion, the unlocking member is allowed to rotate in the other circumferential direction to unlock the locked state of the movable piece.
4. The armrest according to claim 2 , wherein the inner race comprises a first metal part constituting a part of the inner walls of the pocket, and a first resin part, and wherein a rugged portion formed on an inner periphery of the first metal part and a rugged portion formed on an outer periphery of the first resin part are engaged with each other such that the first metal part and the first resin part are assembled together to prevent relative slippage in circumferential directions.
5. The armrest according to claim 2 , further comprising an urging member arranged to urge the movable piece toward the one circumferential direction, wherein the inner race comprises a first metal part constituting a part of the inner walls of the pocket, and a first resin part, wherein a rugged portion formed on an inner periphery of the first metal part and a rugged portion formed on an outer periphery of the first resin part are engaged with each other such that the first metal part and the first resin part are assembled together to prevent relative slippage in circumferential directions, wherein at the outer periphery of the first metal part, the first metal part has an urging member receiving recess which is recessed toward a center of the first metal part to receive the urging member, and wherein the rugged portion of the first metal part has a protrusive portion protruding toward the center of the first metal part, and the protrusive portion is arranged radially inward of the urging member receiving recess.
6. The armrest according to claim 2 , wherein the outer race comprises a second metal part constituting a part of the inner walls of the pocket, and a second resin part, and wherein a rugged portion formed on an outer periphery of the second metal part and a rugged portion formed on an inner periphery of the second resin part are engaged with each other such that the second metal part and the second resin part are assembled together to prevent relative slippage in circumferential directions.
7. The armrest according to claim 6 , wherein the rugged portion of the second metal part has a protrusive portion protruding radially outward, and when the clutch is in the locked state, the protrusive portion is positioned radially outward of the movable piece.
8. The armrest according to claim 2 , wherein the unlocking member has an extension portion extending radially outward, and wherein the first manipulation member engages with the unlocking member at the extension portion, and the first manipulation member is arranged radially outward of the outer race in a region where the first manipulation member and the outer race overlap in an axial direction.
9. The armrest according to claim 2 , wherein the inner walls of the pocket have a projection at one side of the movable piece in the one circumferential direction, and when the inner race and the outer race are forcibly and relatively rotated in a locking direction, the projection contacts the movable piece.
10. The armrest according to claim 2 , wherein the unlocking manipulation mechanism is engaged with or fixed to the unlocking member and includes a second manipulation member extending toward a distal end of the arm frame, and wherein when the second manipulation member is manipulated to rotate the unlocking member in the other circumferential direction, the movable piece is allowed to be unlocked.
11. The armrest according to claim 3 , wherein the unlocking manipulation mechanism is engaged with or fixed to the unlocking member and includes a second manipulation member extending toward a distal end of the arm frame, wherein when the second manipulation member is manipulated to rotate the unlocking member in the other circumferential direction, the movable piece is allowed to be unlocked, wherein the first manipulation member is provided arcuately around an axis of rotation of the arm frame, and the second manipulation member is provided along a longitudinal direction of the arm frame, and wherein the first manipulation member and the second manipulation member are arranged so as not to overlap each other as viewed from an axial direction.
12. The armrest according to claim 3 , wherein the small diameter portion and the large diameter portion are formed as flanges extending from a peripheral edge of the switching member in an axial direction of the switching member.
13. The armrest according to claim 12 , wherein the flange constituting the small diameter portion and the flange constituting the large diameter portion are connected to each other.
14. The armrest according to claim 3 , wherein the return engagement portion is integrally molded with the switching member.
15. The armrest according to claim 8 , wherein the extension portion is integrally molded with the unlocking member.
16. The armrest according to claim 8 , wherein a first attachment member is fixed to the inner race and a second attachment member is fixed to the outer race, wherein one of the first attachment member and the second attachment member has a stopper which protrudes toward the one-way clutch and is engageable with the inner race or the outer race fixed to the other one of the first attachment member and the second attachment member to restrict a rotation range of the one of the first attachment member and the second attachment member, and wherein the stopper is arranged in a region where the stopper and the extension portion overlap in the axial direction and where the stopper and the extension portion do not overlap as viewed from the axial direction.
Applications Claiming Priority (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2011175237A JP5739273B2 (en) | 2011-08-10 | 2011-08-10 | One way clutch |
JP2011-175237 | 2011-08-10 | ||
JP2011175234A JP2013035507A (en) | 2011-08-10 | 2011-08-10 | Armrest |
JP2011-175234 | 2011-08-10 | ||
PCT/JP2012/070032 WO2013021980A1 (en) | 2011-08-10 | 2012-08-07 | Armrest |
Publications (1)
Publication Number | Publication Date |
---|---|
US20140159461A1 true US20140159461A1 (en) | 2014-06-12 |
Family
ID=47668487
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/237,266 Abandoned US20140159461A1 (en) | 2011-08-10 | 2012-08-07 | Armrest |
Country Status (2)
Country | Link |
---|---|
US (1) | US20140159461A1 (en) |
WO (1) | WO2013021980A1 (en) |
Cited By (11)
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---|---|---|---|---|
US20140368017A1 (en) * | 2013-06-14 | 2014-12-18 | Joerg Girbinger | Motor-vehicle armrest |
FR3034724A1 (en) * | 2015-04-10 | 2016-10-14 | Eurostyle Systems | DEBRAYABLE JOINT ARRANGEMENT COMPRISING A PIECE SUCH AS AN ARMREST IN PARTICULAR OF A CENTRAL CONSOLE OF A MOTOR VEHICLE |
WO2018067192A1 (en) * | 2016-10-03 | 2018-04-12 | Porter Systems Inc. | Pawl and sector locking adjustable armrest |
US10080438B2 (en) | 2015-09-21 | 2018-09-25 | Stryker Corporation | Patient support apparatus |
US20180339627A1 (en) * | 2015-09-30 | 2018-11-29 | Grammer Ag | Seat armrest and seat with armrest |
US20190084458A1 (en) * | 2016-03-31 | 2019-03-21 | Ts Tech Co., Ltd. | Armrest |
DE202018105885U1 (en) * | 2018-10-15 | 2020-01-20 | Rollax Gmbh & Co. Kg | Adjustable armrest |
CN112140966A (en) * | 2019-06-28 | 2020-12-29 | 比亚迪股份有限公司 | Side keeps off handrail subassembly and vehicle |
US11027638B2 (en) * | 2018-09-21 | 2021-06-08 | Volvo Car Corporation | Locking mechanisms for a foldable armrest for a seat of a vehicle |
DE202020103917U1 (en) | 2020-07-07 | 2021-10-08 | Rollax Gmbh & Co. Kg | Locking device for a pivotable component |
CN114569263A (en) * | 2022-03-30 | 2022-06-03 | 宁波科艺医疗器械有限公司 | Automatic seat of electronic automatically controlled operation doctor |
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JPH0541458U (en) * | 1991-11-13 | 1993-06-08 | 株式会社アイテス | Armrest device |
JP2000000141A (en) * | 1998-06-17 | 2000-01-07 | Nhk Spring Co Ltd | Stepless adjustable reclining type arm rest device |
JP2002191465A (en) * | 2000-12-25 | 2002-07-09 | Tachi S Co Ltd | Movable armrest structure and one-way clutch for seat |
JP4989245B2 (en) * | 2007-02-07 | 2012-08-01 | キヤノン株式会社 | Image forming apparatus |
JP4222626B1 (en) * | 2008-05-29 | 2009-02-12 | 備前発条株式会社 | Armrest device |
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2012
- 2012-08-07 WO PCT/JP2012/070032 patent/WO2013021980A1/en active Application Filing
- 2012-08-07 US US14/237,266 patent/US20140159461A1/en not_active Abandoned
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US6050645A (en) * | 1998-03-04 | 2000-04-18 | Tachi-S Engineering U.S.A., Inc. | Clutching mechanism for an infinitely adjustable armrest |
US6209960B1 (en) * | 1998-03-04 | 2001-04-03 | Tachi-S Engineering Usa, Inc. | Clutching mechanism for an infinitely adjustable armrest |
Cited By (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20140368017A1 (en) * | 2013-06-14 | 2014-12-18 | Joerg Girbinger | Motor-vehicle armrest |
US9227538B2 (en) * | 2013-06-14 | 2016-01-05 | Grammer Ag | Motor-vehicle armrest |
FR3034724A1 (en) * | 2015-04-10 | 2016-10-14 | Eurostyle Systems | DEBRAYABLE JOINT ARRANGEMENT COMPRISING A PIECE SUCH AS AN ARMREST IN PARTICULAR OF A CENTRAL CONSOLE OF A MOTOR VEHICLE |
US10681982B2 (en) | 2015-09-21 | 2020-06-16 | Stryker Corporation | Patient support apparatus |
US11382811B2 (en) | 2015-09-21 | 2022-07-12 | Stryker Corporation | Patient support apparatus |
US10080438B2 (en) | 2015-09-21 | 2018-09-25 | Stryker Corporation | Patient support apparatus |
US11813213B2 (en) | 2015-09-21 | 2023-11-14 | Stryker Corporation | Patient support apparatus |
US20180339627A1 (en) * | 2015-09-30 | 2018-11-29 | Grammer Ag | Seat armrest and seat with armrest |
US11084407B2 (en) * | 2015-09-30 | 2021-08-10 | Grammer Ag | Seat armrest and seat with armrest |
US20190084458A1 (en) * | 2016-03-31 | 2019-03-21 | Ts Tech Co., Ltd. | Armrest |
US10906441B2 (en) * | 2016-03-31 | 2021-02-02 | Ts Tech Co., Ltd. | Rotably lockable armrest |
WO2018067192A1 (en) * | 2016-10-03 | 2018-04-12 | Porter Systems Inc. | Pawl and sector locking adjustable armrest |
US11027638B2 (en) * | 2018-09-21 | 2021-06-08 | Volvo Car Corporation | Locking mechanisms for a foldable armrest for a seat of a vehicle |
DE202018105885U1 (en) * | 2018-10-15 | 2020-01-20 | Rollax Gmbh & Co. Kg | Adjustable armrest |
DE102019121853B4 (en) | 2018-10-15 | 2023-06-15 | Rollax Gmbh & Co. Kg | Reclining armrest and reclining footrest |
CN112140966A (en) * | 2019-06-28 | 2020-12-29 | 比亚迪股份有限公司 | Side keeps off handrail subassembly and vehicle |
DE202020103917U1 (en) | 2020-07-07 | 2021-10-08 | Rollax Gmbh & Co. Kg | Locking device for a pivotable component |
CN114569263A (en) * | 2022-03-30 | 2022-06-03 | 宁波科艺医疗器械有限公司 | Automatic seat of electronic automatically controlled operation doctor |
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Date | Code | Title | Description |
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AS | Assignment |
Owner name: TS TECH CO., LTD., JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:MOCHIZUKI, HARUKI;ABE, RYUZABURO;SIGNING DATES FROM 20140128 TO 20140129;REEL/FRAME:032147/0274 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |