CN1863471B

CN1863471B - Backrest reclining apparatus

Info

Publication number: CN1863471B
Application number: CN2004800292593A
Authority: CN
Inventors: 堀木敏幸
Original assignee: Kokuyo Co Ltd
Current assignee: Kokuyo Co Ltd
Priority date: 2003-10-29
Filing date: 2004-10-29
Publication date: 2010-06-02
Anticipated expiration: 2024-10-29
Also published as: JP2005131047A; CN1863471A; JP4445244B2; WO2005039357A9; WO2005039357A1

Abstract

A backrest reclining apparatus for tiltably connecting the backrest of a chair or a seat for a vehicle to the seat thereof. To reduce a load on the hip portion or the waist and back portions of a seated person when the backrest is tilted, the rotating center (C) of the backrest (2) is set over the bearing surface (S1) of the seat and forward of the backrest surface (S2) of the backrest and on the side closer to the bearing surface (S1) and the backrest surface (S2) than the trochanterion (P2) of the seated person seating on the seat (3).

Description

Backrest reclining apparatus

Technical field

The present invention relates to backrest reclining apparatus.Again in detail, the present invention relates to the structure of the backrest reclining apparatus that the backrest at chair or used for vehicle seat can be connected with the seat with fascinating.

Background technology

In the past, can be connected swing chair or used for vehicle seat on the seat for backrest with fascinating, open flat 5-8676 number, spy and open flat 6-253943 number, real opening and go up for flat 6-64546 number like that as being disclosed in the disclosed spy in the Japan Patent Room, the pivot that makes backrest is arranged and be called the corresponding to technology of point that the side of femoral joint axle of the seated person of rotor point is seen.Fig. 7 is according to above-mentioned conventional art, represents with rotor point P2 to be that center back side rotates backrest 101 and the seated person before and after promptly fascinating that backrest 101 that double dot dash line is described and seated person are represented the state after the hypsokinesis.In the conventional art, pivot C by making backrest 101 and seated person above the waist with respect to the lower part of the body carry out crooked point be rotor point P2 consistent or be set in rotor point P2 near, and the track when seated person back is toppled over is roughly consistent with the track that fascinates of backrest 101, prevent to produce between backrest 101 and the seated person back and slide, prevent that the phenomenon of wrinkle from appearring in clothes, alleviates the sticky feeling for back.

But, as described in above-mentioned conventional art, in the pivot C that makes backrest 101 occasion consistent with rotor point P2, because following backrest 101 is that the center is rotated to the moving ischial tuberosity 102 of back side inclination with rotor point P2, and shown in Fig. 7 double dot dash line, desire forwards and than seat surface S101 more moves the below, therefore, sometimes ischial tuberosity 102 is pressed to seat surface S101 by brute force, to the buttocks effect of seated person stronger plus-pressure, seated person is caused sense of discomfort.In addition, the result that ischial tuberosity 102 is met seat surface S102, limited by seat surface S101 around the rotation of the ischial tuberosity 102 of rotor point P2, suppress the rearward rotation of seated person pelvis, it is antecurvature and make the seated person spine become case of bending, the seated person the small of the back is increased burden to encourage undue lumbar vertebrae.

In addition, return to initial position, generally use compression helical spring in order to make the backrest after fascinating.In this occasion, owing to rotatablely moving of backrest need be transformed into rectilinear motion and pass to the linkage of compression helical spring, so mechanism's complexity, part number and to assemble number more makes manufacturing expense etc. increase.And, use the long compression helical spring of total length, the problem that mechanism is maximized in the fascinate occasion of scope of bigger setting backrest.For the position of rotation with backrest changes the savings that is directly used in restoring force, though also can consider bar-shaped torsionspring is installed in scheme on the rotating shaft of backrest, but, must be that the shoulder breadth direction of seated person obtains bigger spring setting and uses the space at the width of chair because of bar-shaped torsionspring needs the length of length direction.In addition, the spring constant of compression helical spring and bar-shaped torsionspring is generally higher, sharply increases with respect to the counter-force of camber of spring.Thoughts and feelings when therefore, backrest being fascinated has to be felt not only heavily but also hard tendency.So there is burden to act on the anxiety of seated person back.Not only light but also soft usability when realizing that backrest fascinates, also can consider to use the rubber that spring constant is little to be installed in torsionspring between concentric shape cylinder element and the backrest rotating shaft, but this moment, must the elastomeric material sintering is integrated on metal cylinder element and rotating shaft, when discarded, metal material separates with elastomeric material is extremely difficult, causes environmental problem.

Summary of the invention

The objective of the invention is to, provide a kind of backrest when fascinating, can alleviate backrest reclining apparatus seated person buttocks and the small of the back burden.In addition, the objective of the invention is to, provide a kind of like this backrest reclining apparatus: can easily tackle the fascinate requirement of scope of bigger setting backrest, and not only light but also soft usability when realizing that backrest fascinates, also can solve with the elastomeric material sintering on metal material, produced discarded the time environmental problem.

For achieving the above object, backrest reclining apparatus of the present invention, backrest can be connected on the seat with fascinating, and the pivot of backrest is set in upper/lower positions: be positioned at the place ahead of forefront point with the top of seat surface consistent location or seat surface and the vertical central authorities on the surface of the backrest that is in initial position and than sitting in seated person rotor point on the seat more near a side of seat surface and more near a side of backrest surface.

The position of the rotor point in the relation of above-mentioned position, the position the when seated person that is meant average or desirable physique is taken one's seat very naturally.The position of this rotor point is to wait according to ergonomics and statistics to try to achieve as the conventional art of having narrated discloses.In addition, with the ischial tuberosity of the seated person that takes a seat with very natural posture on be called the ischial tuberosity point with the immediate point of seat surface.And the initial position of so-called backrest, the effect of being meant not makes the position of backrest of the state of the load that backrest fascinates.

The ischial tuberosity point of seated person is positioned at than more close seat surface of seated person rotor point and more close backrest face.Therefore, the pivot of the backrest of above-mentioned setting be set to the distance of ischial tuberosity point than to the short position of the distance of rotor point, that is to say, be set near the of ischial tuberosity point or with ischial tuberosity point consistent location.Therefore, follow that backrest fascinates and the ischial tuberosity of the seated person that rotates is heavy to the below of seat surface, can it be fascinated.Thus, the ischial tuberosity that can prevent to concentrate the seated person body weight is pressed against situation on the seat surface by brute force, and can alleviate the surface pressure that acts on the seated person buttocks from seat surface.In addition, owing to ischial tuberosity fascinates on seat surface naturally, so along with the back of seated person falls down, the pelvis of seated person is fulcrum rotation rearward naturally with the ischial tuberosity point also.Therefore, can prevent that undue lumbar vertebrae is antecurvature, prevent that promptly the spine of seated person from becoming the state of undue bending, also can alleviate burden the seated person the small of the back.

Here, in the inconsistent and occasion near the pivot of setting backrest ischial tuberosity point of the pivot of backrest and ischial tuberosity point, than the pivot with backrest be located at ischial tuberosity point the place ahead be seated person towards a side, preferably the pivot with backrest is set in the rear side that ischial tuberosity point rear is a seated person.If the pivot of backrest is in the place ahead of ischial tuberosity point, then when making the backrest hypsokinesis, because ischial tuberosity is desired more to move the below to seat surface, the bone ischial tuberosity presses against on the seat surface and plus-pressure is acted on the buttocks of seated person, but be set in the rear of ischial tuberosity point by pivot with backrest, ischial tuberosity is desired above seat surface to move when making the backrest hypsokinesis, can prevent that therefore ischial tuberosity from being pressed against situation on the seat surface by brute force, can alleviate the plus-pressure to the seated person buttocks.

In addition, for the pivot with backrest is set in above-mentioned position, 2 seat side arms that the revolute pair of the most handy formation backrest pivot will be extended upward from the both sides, seat are connected with 2 backrest side arm portions of forwards extending from the both sides of backrest.

By having the linkage of sliding pair and a plurality of revolute pairs etc., the rotating shaft of imaginary backrest can be set in position as purpose.On the other hand, as mentioned above, by the pivot of directly determining backrest that is connected by seat side arm and backrest side arm portion, the linkage of the complexity that realizes imaginary rotating shaft then needn't be set between seat and backrest, simplifying the structure of backrest reclining apparatus can be made, also the backrest reclining apparatus miniaturization can be made.In addition, owing to needn't guarantee the space that linkage is used is set between seat and backrest,, also can set seat surface lower so can improve the free degree of seat and backrest design.

In addition, counterforce device is installed in the coupling part that is preferably in described seat side arm and backrest side arm portion, to make this backrest return to the counterforce device of initial position at the backrest that fascinates.

In this occasion, needn't guarantee below the seat and the rear side of backrest etc. is provided with the space that counterforce device is used.Thus, more miniaturization of backrest reclining apparatus can be can further improve the free degree of seat and backrest design, also can set seat surface lower.

In addition, described counterforce device has preferably that an end is installed on the seat side arm, the other end is installed in the volute spring in the backrest side arm portion.

Because volute spring is the structure that produces elastic force by rolling-in,, can make the volute spring savings to the counter-force that backrest is returned to the direction of initial position so directly utilize the moment of torsion that rotation produced of backrest with respect to the seat.Thus, do not need backrest is transformed into the linkage that rectilinear motion is used with respect to rotatablely moving of seat, can help simplification, part number and the minimizing of assembling number and then the minimizing of manufacturing expense of mechanism.In addition.Volute spring is because of constituting concentric vortex, so can be to axially not outstanding as bar-shaped torsionspring and torsion-coil spring etc.Therefore, can suppress spring shared space occupancy and obtain required elastic force in counterforce device.And volute spring not only compactness is that space occupancy is less, and compares with bar-shaped torsionspring etc. with compression helical spring, and the scope of variable bit is big.Therefore, as compact structure, also can set the scope of fascinating of backrest significantly.In addition, the spring constant of volute spring is compared less with compression helical spring with bar-shaped torsionspring etc.In other words, the increase of its counter-force of volute spring is that the increase of backrest turning angle is less with respect to the increase of displacement, and backrest begins from fascinating to finishing to take place roughly certain counter-force.Therefore, burden can not act on the back of seated person when backrest fascinates, and can realize not only light but also soft comfortable usability.And, do not use elastomeric material just can realize aforesaid not only light but also soft backrest sensation, in discarded occasion etc., also incorporate elastomeric materials such as no-trump and the metal material this trouble of separating.

In addition, the periphery of the installation shaft that the vortex center side end of above-mentioned volute spring is installed, preferably constitute closed curve shape (except just the circle).In this occasion, can prevent situation about being close between the wire rod of volute spring volute spring when rolling-in, prevent that the elastic force of volute spring from descending, and can prevent that overload from acting on volute spring and making its damaged situation.

In addition, be provided with the connecting portion of disc-shape respectively with same outer diameter as in seat side arm portion and backrest side arm portion, the connecting portion of these dorsal parts can be rotated relatively with the chimeric one-tenth of the connecting portion of seat side, and be preferably in the dorsal part connecting portion after chimeric and the built-in above-mentioned volute spring in inner space of seat side connecting portion.In this occasion, can take in counterforce device in the coupling part of seat side arm portion and backrest side arm portion, can obtain the further miniaturization and the simplification of backrest reclining apparatus.In addition, owing to can't see the outward appearance of volute spring from the outside,, do not have the accident that hand or article are clamped by volute spring so outward appearance is good yet.

Adopt backrest reclining apparatus of the present invention, since with the pivot of backrest be set in to the distance of ischial tuberosity point than to rotor point apart from the position of lacking, in other words near ischial tuberosity point or with ischial tuberosity point consistent location, prevent that ischial tuberosity that the body weight of seated person concentrates from being pressed against situation on the seat surface by brute force, so can alleviate the plus-pressure that acts on the seated person buttocks from seat surface, and the spine that can prevent seated person becomes the state of undue bending, also can alleviate the burden to the seated person the small of the back.In addition, because the pelvis of seated person fascinates naturally according to fascinating of backrest, so than the pivot that the makes backrest occasion consistent with rotor point, can increase the angle of bend of the femoral joint that seated person fascinates with backrest slightly, can when backrest fascinates, give the bigger opening of seated person and feel.On the contrary,, obtain the backrest reclining apparatus of fully open sense in the time of also can being provided at backrest and fascinating, help the downsizing that the space is set at chair or used for vehicle seat even reduce the maximum inclination angle of backrest.In addition because backrest contact the amount of sliding with the back of seated person also little, so also can obtain with prevent clothes generation wrinkle phenomenon etc., and make backrest pivot and rotor put the identical effect of corresponding to occasion.

Description of drawings

Fig. 1 is the side view that expression is applied to backrest reclining apparatus of the present invention an embodiment behind the rotating chair.

Fig. 2 is the stereogram of the backrest of the above-mentioned chair of expression.

Fig. 3 is the stereogram that backrest side arm portion is amplified expression.

Fig. 4 is the stereogram that the seat side arm is amplified expression.

Fig. 5 is the side view of counterforce device that expression is assembled in the coupling part of seat side arm and backrest side arm portion.

Fig. 6 is that expression is center, the backrest of hypsokinesis front and back and the side view of seated person with the ischial tuberosity point.

Fig. 7 is the backrest reclining apparatus of representing in the past, is that expression is center, the backrest of hypsokinesis front and back and the side view of seated person with the rotor point.

Symbol description

The 1st, chair

The 2nd, backrest

The 3rd, the seat

The 5th, backrest reclining apparatus

The 6th, the seat side arm

6b is the seat side connecting portion

The 7th, backrest side arm portion

7b is the dorsal part connecting portion

The 13rd, counterforce device

The 14th, volute spring

C is the pivot of backrest

P1 is the ischial tuberosity point

P2 is the rotor point

S1 is seat surface (surface at seat)

S2 is backrest face (surface of backrest)

The specific embodiment

Embodiment shown in reference to the accompanying drawings describes formation of the present invention in detail below.

Fig. 1 to Fig. 6 represents an embodiment of backrest reclining apparatus of the present invention.In the present embodiment, the occasion that backrest reclining apparatus 5 of the present invention is applied to the rotating chair 1 that office that backrest can fascinate uses describes.And in this manual, so-called the place ahead is meant the face side of seated person, and the top is meant the upside of vertical.

Have backrest 2 can be connected in the chair 1 of the backrest reclining apparatus 5 on the seat 3 with fascinating, the pivot C of backrest 2 is set in following position, that is: with the top of seat surface S1 consistent location or seat surface S1 and on the surface of the backrest 2 that contacts with the back of seated person be backrest face S2 vertical central authorities the backrest face that is positioned at S2 forefront point (hereinafter referred to as the backrest point) the place ahead the position and also be in position than more close seat surface S1 of the rotor point P2 of the seated person that occupies seat 3 and more close backrest face S2.For example in the present embodiment as shown in Figure 1, with compare from the pivot C of backrest 2 to the distance of rotor point P2, the position that distance from the pivot C of backrest 2 to ischial tuberosity point P1 is short, in other words, near the ischial tuberosity point P1, more particularly, than ischial tuberosity point P1 after a while the side and slightly above the pivot C of set positions backrest 2.But, as shown in Figure 6, also can see the pivot C that sets backrest 2 with ischial tuberosity point P1 consistent location from the side.Here, when the pivot C that makes backrest 2 and tubercle point P1 inconsistent, and near ischial tuberosity point P1 during the pivot C of setting backrest 2, compare with the place ahead that pivot C is set in ischial tuberosity point P1, as present embodiment pivot C is set in the rear of ischial tuberosity point P1.If pivot C is in the place ahead of ischial tuberosity point P1, then when making backrest 2 hypsokinesis, ischial tuberosity 4 is just desired to move to the more below of seat surface S1, ischial tuberosity 4 can be pressed against on the seat surface S1, the buttocks of seated person is applied plus-pressure, if pivot C is set in the rear of ischial tuberosity point P1, then when making backrest 2 hypsokinesis, desire to make ischial tuberosity 4 to move, be pressed at full tilt on the seat surface S1, can alleviate plus-pressure the seated person buttocks so can prevent ischial tuberosity 4 to the top of seat surface S1.

Here, as shown in Figure 1, ischial tuberosity point P1 compares more close seat surface S1 and more close backrest face S2 with the rotor point P2 of seated person.Wait according to ergonomics and statistics to obtain the rotor point P2 of chair 1 as the average or desirable seated person of object, same, the ischial tuberosity point P1 of average or desirable seated person also can wait according to ergonomics and statistics and obtain.For example, chair 1 is projected to the left and right directions plane orthogonal on the time, promptly from the side of chair 1, distance at the above-below direction of point that will join with the plumb line of the axle quadrature of backrest 2 pivot C and vertical central authorities that 3 central longitudinal cross sections, seat are seat surface S1 and pivot C looks like to be made as shown in Figure 1 a, the point that will be positioned at the forefront on the central longitudinal cross section of the backrest 2 that is in initial position is that the distance picture of the fore-and-aft direction of backrest point and pivot C is made as b as shown in Figure 1, then a preferably makes about 0cm～7cm, and b preferably makes about 4cm～12cm.In addition, seat surface S1 and backrest face S2 need not to be the plane, from viewpoint of ergonomics and processing attractive in appearance etc., also can adopt suitable curve form etc.For example, the backrest face S2 of present embodiment forms to the outstanding curve form of seated person waist, and seat surface S1 is such as shown in phantom in Figure 1, and the part relative with the seated person buttocks forms the curve form of depression slightly.So, be not the occasion on plane at seat surface S1, when setting the pivot C of backrest 2, with vertical Central Line of seat surface S1 as benchmark.Therefore, the axis of imaginaries of the pivot C of backrest 2 just intersects with vertical Central Line of seat surface S1, or the top of the vertical Central Line by seat surface S1.

In addition, in the present embodiment, 3 both sides to 2 seat side arms 6 of the top of seat surface S1 extension and 2 backrest side arm portions 7 of extending to the place ahead of backrest face S2 respectively from backrest 2 both sides, connect with the revolute pair that constitutes backrest 2 pivot C respectively respectively from the seat.Sometimes also can backrest 2 be connected with seat 3 by linkage, at the above-mentioned imaginary rotating shaft of set positions that becomes backrest 2 pivot C, backrest 2 is fascinated around this imagination rotating shaft, but so constitute by present embodiment, the linkage of the complexity that for example has sliding pair or a plurality of revolute pairs etc. needn't be set between seat 3 and backrest 2, can make simplifying the structure of chair 1, obtain the miniaturization of backrest reclining apparatus 5.Thus, can improve the free degree of the designs such as shape of chair 1, also can set seat surface S1 lower.

The backrest 2 of present embodiment comprises: the backrest body 2a that for example forms backrest face S2; The inner jacket member 2b that backrest body 2a is supported from rear side; Cover the back of the body lid 2c at the inner jacket member 2b back side.One of each backrest side arm portion 7 distolaterally is provided with the fixing member 7a that use integratedly, and this is fixed with member 7a by the fastening bottom that is fixed on backrest 2 of screw.More particularly, as shown in Figure 3, will fix the dorsal part that is fastened on inner jacket member 2b lower end with member 7a by installing plate 8 usefulness bolts and nut, fastening after, will fix to cover and hide, and as shown in the figure, the back of the body covers 2c and is installed on the inner jacket member 2b with member 7a.Symbol 9 among Fig. 3 is that the fixing of backrest side arm portion 7 is fastened on the hole of using on the inner jacket member 2b with member 7a screw.In addition, cover to be formed with on the 2c at the back of the body and illustrate abridged card claw stop, be embedded in the hole, diagram abridged of being located at inner jacket member 2b, cover 2c and be installed on the inner jacket member 2b and will carry on the back by blocking claw stop.Each backrest side arm portion 7 forwards and slightly downwards extends after the left and right sides direction outside extension in a single day to the left and right of backrest 2 bottoms.Front end in each backrest side arm portion 7 is provided with dorsal part connecting portion 7b integratedly.

In addition, the seat 3 of present embodiment constitutes by the seat body 3a that for example forms seat surface S1 with to the seat supporting member 3b that this seat body 3a supports.At the lower surface of seat supporting member 3b the distolateral of rotatable pin axle 10, the distolateral pin blade 12 with castor 11 that is equipped with of another of pin axle 10 are installed.Seat side arm 6 comprises: be fixed on arm base portion 6a on the seat supporting member 3b with fixed forms such as welding; With the fastening installation portion 6c that is fixed on the arm base portion 6a of screw; Be set as seat side connecting portion 6b with installation portion 6c one.Arm base portion 6a extends after in a single day extend in the direction outside to the left and right from supporting member 3b two sides, seat upward and slightly rearward.At each front end of arm base portion 6a, fastening and will be fixed on installation portion 6c on the seat side connecting portion 6b and be inserted fixing by screw respectively.

Dorsal part connecting portion 7b and seat side connecting portion 6b form for example has same outer diameter as and inner disc-shape with space, and as shown in Figure 2, can be rotated relatively by the pivot C of chimeric one-tenth around backrest 2 mutually.And, in the present embodiment,, be seat side connecting portion 6b and dorsal part connecting portion 7b for example in the coupling part of seat side arm portion 6 and backrest side arm portion 7 as shown in Figure 5, packing into makes the backrest 2 that fascinates return to the counterforce device 13 of initial position.Occasion in this structure, owing to taken in counterforce device 13 with the coupling part of backrest side arm portion 7 in seat side arm portion 6, so needn't be below seat 3 and the dorsal part of backrest 2 etc. being provided with of counterforce device 13 be set use the space, the structure of chair 1 is more oversimplified, further improve the free degree of the designs such as shape of chair 1, also can set seat surface S1 lower.

In addition, for example in the present embodiment, above-mentioned counterforce device 13 uses an end to be installed on the seat side connecting portion 6b of seat side arm 6, and the other end is installed in the volute spring 14 on the dorsal part connecting portion 7b of backrest side arm portion 7.Elastic force owing to take place by rolling-in in volute spring 14, so can directly utilize the rotation torque that circular motion produced at backrest 2 relative seats 3, the counter-force that makes backrest 2 return to the direction of initial position is put aside in volute spring 14.Therefore, do not need backrest 2 rotatablely moving of relative seat 3 are transformed to the linkage that rectilinear motion is used, help the minimizing of simplification, part number and the assembling number of mechanism, and then reduce manufacturing expense etc.Also have, because volute spring 14 constitutes vortex shape, so it can be not outstanding to a direction as bar-shaped torsionspring or torsion-coil spring etc.Therefore, can suppress space occupancy and obtain required elastic force.And volute spring 14 not only compactness is that space occupancy is less, and compares with compression helical spring or bar-shaped torsionspring etc., and the scope of variable bit is also big.Therefore, as compact structure, also can set the scope of fascinating of backrest 2 bigger.In addition, compare with compression helical spring or bar-shaped torsionspring etc., the spring constant of volute spring 14 is also little.In other words, the counter-force that the increase of the displacement of volute spring 14 promptly increases with respect to backrest 2 turning angles increases less, begins to finishing to take place roughly certain counter-force from fascinating of backrest 2.Therefore, when backrest 2 fascinates, can not cause burden, can realize not only light but also soft comfortable usability the back of the body of seated person.And, owing to do not use elastomeric material just can realize aforesaid not only light but also soft backrest sensation, so in the occasion of discarding chair 1 etc., do not have the sort of problem that will be separated with incorporate rubber such as metal material.

Volute spring 14 is that the elasticity raw material with band shape are rolled into volute member.The both ends of volute spring 14 form hook-like, upward only to block by being hooked on seat side connecting portion 6b and dorsal part connecting portion 7b respectively.Below, the hook of the central side end that is formed at vortex is called interior hook 14a, the hook of the outer circumferential side end that is formed at vortex is called outer hook 14b.Interior hook 14a and outer hook 14b preferably do not have wedge angle and partly form circular curved surface shape and cause breakage because of preventing that stress is concentrated.The number of volute spring 14, material, size etc. also can suitably select to be used for obtaining number, material, size of required elastic force etc., for 1 couple of seat side connecting portion 6b and dorsal part connecting portion 7b, and the volute spring 14 more than 2 of also can packing into.For example in the present embodiment, the raw material of volute spring 14 use the hard steel wire rod, dispose 1 volute spring 14 at the seat side connecting portion 6b that is formed at after chimeric with dorsal part connecting portion 7b volume inside.Therefore, be respectively arranged with 1 in the left and right sides of chair 1 and add up to 2 volute springs 14.

As Fig. 3 and shown in Figure 5, dorsal part connecting portion 7b forms face one side relative with seat side connecting portion 6b discoid by open hollow, is formed with the 1st protuberance 15 to the inboard of dorsal part connecting portion 7b outer peripheral edges depression at the inner peripheral of dorsal part connecting portion 7b.The 1st protuberance 15 forms the circular-arc C of the being shape after a part of will justify cuts.Cut-away is as the space that the end (outer hook 14b) in volute spring 14 outsides is accommodated.In addition, the part of the 1st protuberance 15 is outstanding to the center of dorsal part connecting portion 7b inside, and this ledge constitutes rotation restriction portion 16.Central part in dorsal part connecting portion 7b inside is provided with installation shaft 17, and it has the groove 17a with the interior hook 14a hook of volute spring 14.

As shown in Figure 4, seat side connecting portion 6b also forms face one side relative with dorsal part connecting portion 7b discoid by open hollow, at the inner peripheral of seat side connecting portion 6b, be formed with the 2nd protuberance 18 in dorsal part connecting portion 7b is given prominence to and embeds in the outside of seat side connecting portion 6b outer peripheral edges.The 2nd protuberance 18 form will circle a part make circular-arc C shape after cutting.Be entrenched in by in the depressed part that is constituted between the 1st protuberance 15 of dorsal part connecting portion 7b and the surrounding edge thereof by the teat that constitutes by the 2nd protuberance 18, thereby be connected to rotatable.In addition, in the interior week of the 2nd protuberance 18, as shown in Figure 5, with chimeric the 1st restriction portion 19 of the rotation restriction portion 16 of dorsal part connecting portion 7b and the 2nd restriction portion 20 be formed on will 16 clampings of rotation restriction portion the position.And, be provided with spring hook portion 21 with the outer hook 14b hook of volute spring 14 at the inner peripheral of seat side connecting portion 6b.This spring hook portion 21 is set as: be hooked on the discontinuities office that outer hook 14b in the spring hook portion 21 is positioned at the 2nd protuberance 18 and the 1st protuberance 15, for example, be set as one with the 2nd restriction portion 20.In addition, the central part in seat side connecting portion 6b inside is provided with the hole 22 of rotatably chimeric installation shaft 17.

Therefore, when the interior hook 14a with volute spring 14 is hooked in the groove 17a of installation shaft 17, outer hook 14b is hooked in the spring hook portion 21, make the 2nd protuberance 18 and the 1st protuberance 15 chimeric, and pass through in installation shaft 17 patchholes 22, and make dorsal part connecting portion 7b and seat side connecting portion 6b chimeric, will ensconce by in dorsal part connecting portion 7b and the formed inner space of seat side connecting portion 6b in the volute spring 14.Owing to can't see volute spring 14 from the outside,, and do not have yet and point or accident that article are clamped by volute spring 14 so outward appearance is good.In addition, the anti-avulsion member is installed, to prevent the comes out of engagement of seat side connecting portion 6b and dorsal part connecting portion 7b reliably at installation shaft 17 end faces that run through the hole 22 that is located on the seat side connecting portion 6b.Specifically, on the limit of the groove 17a of installation shaft 17, be provided with 2 screw holes 30, the disc 31 of diameter greater than hole 22 be fixed on installation shaft 17 end faces that run through hole 22 by 2 screws that are screwed into described 2 screw holes 30.Thus, seated person even act on excessive load, also can prevent the phenomenon of the comes out of engagement of seat side connecting portion 6b and dorsal part connecting portion 7b reliably when backrest 2 is fascinated, and can avoid backrest 2 to throw off the danger of chair 1.

Distinguish chimeric dorsal part connecting portion 7b and seat side connecting portion 6b by the left and right sides, thereby backrest 2 rotatably is connected with seat 3, and forbid moving of this rotation backrest 2 in addition at chair 1.And as shown in Figure 5, utilize with the rotation restriction portion 16 of dorsal part connecting portion 7b one rotation, be set as the 1st restriction portion 19 and the 2nd restriction portion 20 of one, limit the rotating range of backrest 2 with seat side connecting portion 6b.That is, the elastic force that volute spring 14 produces makes rotation restriction portion 16 and the 2nd restriction portion 20 butts of dorsal part connecting portion 7b.The state of rotation restriction portion 16 and the 2nd restriction portion 20 butts becomes the state that backrest 2 is in initial position.On the other hand,, that is, make dorsal part connecting portion 7b relative seat connecting portion 6b rotation on one side if the elastic force that overcomes volute spring 14 fascinates backrest 2, rotate restriction portion 16 just with the 1st restriction portion 19 butts.The state of rotation restriction portion 16 and the 1st restriction portion 19 butts becomes the state that backrest 2 is the most rearward toppled over.

Here, when with volute spring 14 rolling-in, if be close between the wire rod of formation vortex, the inside part of then being close to part at it, because volute spring 14 does not play the effect of spring in fact, so can not obtain sufficient elastic force, and the 14 effect overloads of pair volute spring are arranged and make the anxiety of volute spring 14 breakages.Therefore in the present embodiment, the periphery of installation shaft 17 is made just be not circle but the roughly shape of closed curve, for example substantially elliptical shape.Thus, can prevent being close between the wire rod of volute spring 14, prevent above-mentioned the sort of unfavorable condition.

In addition, on the face of the opposition side of the face relative in seat side connecting portion 6b, for example put arm member 23 by fastening being equipped with of screw with dorsal part connecting portion 7b.Symbol 24 among Fig. 4 is to be used for being fastened on screw hole on the seat side connecting portion 6b with putting arm member 23 screws, and the symbol 25 among Fig. 2 is to be inlaid in the lid of putting on the arm member 23 after this screw is fastening.Constitute the material of each member of the chair 1 of above explanation, can suitably select to have must or the metal material of desirable mechanical strength, light weight, weather resistance, handling ease etc. or synthetic resin etc.For example in the present embodiment, by the casting die of using aluminium alloy that backrest side arm portion 7 is integrally formed, also that seat side connecting portion 6b and installation portion 6c is integrally formed by the casting die of using aluminium alloy.In addition, the inner jacket member 2b of backrest 2 is that polypropylene is made.For backrest body 2a and seat body 3a, use by skin members such as the cloth member that encases such as foamed resin such as urethane or fibrous padded coaming for example.

Adopt the chair 1 of present embodiment as constituted above, backrest 2 fascinates as following.That is, when seated person leaned against on the backrest 2 that is in initial position service load, backrest 2 was that the center is rotated with swinging to the rear with the C point just.The pivot C of backrest 2 be set in ischial tuberosity point P1 near.Here, it is that center back side rotation is backrest 2 and the seated person before and after the hypsokinesis that Fig. 6 represents with ischial tuberosity point P1, the state that backrest 2 that is drawn by double dot dash line and seated person are represented hypsokinesis.As shown in the drawing, be that the ischial tuberosity 4 of the seated person of center rotation can not desired to avale to the more below of seat surface S1 with ischial tuberosity point P1, and on seat surface S1, fascinate.Therefore, by the pivot C with backrest 2 be set in ischial tuberosity point P1 near, especially as present embodiment, pivot C is set in rear slightly than ischial tuberosity point P1, just can prevent that the ischial tuberosity 4 that supports the seated person body weight from being pushed hard situation about being pressed on the seat surface S1, can alleviate the face that comes from seat surface S1 that acts on the seated person buttocks and press.In addition, because ischial tuberosity 4 fascinates on seat surface S1 naturally, so along with seated person back is toppled over, the pelvis of seated person is a fulcrum and rearward rotating naturally with ischial tuberosity point P1 also.Therefore, can prevent that undue lumbar vertebrae is antecurvature, promptly prevent the undue crooked state of seated person spine, and can alleviate burden the seated person the small of the back.In addition, because the pelvis of seated person fascinates naturally according to fascinating of backrest 2, so compare with the prior art shown in Figure 7 that the pivot C that makes backrest 2 is consistent with rotor point P2, can increase the angle of bend that the femoral joint of seated person fascinates with backrest 2 slightly, when backrest 2 fascinates, can give seated person open sense.On the contrary, even reduce the maximum turning angle of backrest 2, the swing chair 1 that also can provide backrest 2 to obtain fully open sense when fascinating can be tackled the chair needs that the space downsizing is set.In addition, the occasion etc. that is set in the occasion of seat surface S1 below with pivot C with backrest 2 or is set in backrest face S2 rear is compared, because it is little that backrest 2 contact seated person back produce the quantitative change of sliding, thus can obtain to prevent to make clothes generation wrinkle phenomenon etc., with the identical effects such as occasion of pivot C that makes backrest 2 and rotor point P2 unanimity.

And along with backrest 2 relative seat 3 rearward rotations, also relative seat side arm 6 with installation shaft 17 of backrest side arm portion 7 and dorsal part connecting portion 7b and seat side connecting portion 6b are rotated, with volute spring 14 rolling-in.Thus, volute spring 14 desires to make backrest 2 to return to the counter-force of initial position.Here, volute spring 14 produces roughly certain counter-force owing to the increase of the counter-force that the turning angle with respect to backrest 2 increases is less, so can not cause burden to the back of the body of seated person, can give the not only light but also soft mood of seated person good sensation when backrest 2 fascinates.If the external force of backrest 2 hypsokinesis is removed, backrest 2 returns to initial position because of the restoring force of volute spring 14.Adopt the chair 1 of present embodiment, can not make seat 3 interlocks, only backrest 2 fascinates, and can realize not having the comfortable usability of sense of discomfort.

In addition, the above embodiments are preferable embodiment of the present invention, but are not limited to this, without departing from the spirit and scope of the present invention, can do various distortion.For example, in the above-described embodiment, illustrated backrest reclining apparatus 5 of the present invention be used to the to handle official business example of rotating chair 1 of usefulness, but the present invention can be used for other chairs certainly, for example operation with all chairs such as chair, medical chairs, also can be used for the present invention used for vehicle seats such as automobile with chair, nursing.In addition, in the above-described embodiment, packed into and used the counterforce device 13 of volute spring 14 in the coupling part of seat side arm 6 and backrest side arm portion 7, but not necessarily be limited to this example, for example, the motor etc. of also can packing in this coupling part fascinates by the electronic backrest 2 that makes.

In addition, in the above-described embodiment, be that revolute pair with the pivot C that constitutes backrest 2 couples together seat 3 and backrest 2, but also can backrest 2 be connected with seat 3, at the imaginary rotating shaft of set positions of the pivot C that becomes backrest 2 by linkage.In addition, adopt the present invention,, also can give the unexistent in the past mood of seated person good backrest sensation as described above even only backrest 2 fascinates, but also can be by with fascinating of backrest 2 linkage of seat 3 swings being connected backrest 2 with seat 3.In the above-described embodiment, the pivot C of backrest 2 is located at the top of seat surface S1, but also pivot C can be located at seat surface S1 consistent location.Here, for " with seat surface S1 consistent location ", also comprise consistent location roughly with seat surface S1.

In addition, in the above-described embodiment,, and used disc 31, used the structure of anti-avulsion with member but be not limited to as the anti-avulsion member for the phenomenon of the comes out of engagement that prevents seat side connecting portion 6b and dorsal part connecting portion 7b reliably.For example, seat side arm 6, backrest side arm portion 7 and installing plate 8 are for example made metal system, improve the rigidity of these members, when seated person fascinates backrest 2, prevent that seat side arm 6, backrest side arm portion 7 and inner jacket member 2b from producing deflection deformation.Thus, when seated person fascinates backrest 2, can prevent to make the comes out of engagement of seat side connecting portion 6b and dorsal part connecting portion 7b, can avoid backrest 2 to break away from the danger of chair 1 because of above-mentioned deflection deformation.

Claims

1. backrest reclining apparatus, backrest can be connected with the seat with fascinating, it is characterized in that, the pivot of described backrest is set in upper/lower positions: be positioned at described seat surface consistent location and be positioned at that that be positioned at the forefront than the vertical central authorities on the surface of the described backrest on the initial position put more the place ahead and than a side that sits in the more approaching described seat surface of seated person hip joint on the described seat and a side of more approaching described backrest surface; Perhaps be positioned at the top of described seat surface and be positioned at that that be positioned at the forefront than the vertical central authorities on the surface of the described backrest on the initial position put more the place ahead and than a side that sits in the more approaching described seat surface of seated person hip joint on the described seat and a side of more approaching described backrest surface.

2. backrest reclining apparatus as claimed in claim 1 is characterized in that, near the ischial tuberosity point of described seated person or with this ischial tuberosity point consistent location, be set with the pivot of described backrest.

3. backrest reclining apparatus as claimed in claim 1 is characterized in that, in the side than the more approaching described backrest surface of ischial tuberosity point of described seated person, is set with the pivot of described backrest.

4. backrest reclining apparatus as claimed in claim 1, it is characterized in that, 2 seat side arms that extend upward from the both sides at described seat and 2 backrest side arm portions of forwards extending from the both sides of described backrest, the revolute pair by the pivot that constitutes described backrest is connected respectively.

5. backrest reclining apparatus as claimed in claim 4 is characterized in that, in the coupling part of described seat side arm and described backrest side arm portion counterforce device is installed, so that the described backrest that fascinates returns to initial position.

6. backrest reclining apparatus as claimed in claim 5 is characterized in that, described counterforce device has that an end is installed on the described seat side arm, the other end is installed in the volute spring in the described backrest side arm portion.

7. backrest reclining apparatus as claimed in claim 6 is characterized in that, the periphery of the installation shaft that the vortex center side end of described volute spring is installed, be constitute closed curve, except the shape the circle just.

8. backrest reclining apparatus as claimed in claim 6, it is characterized in that, be provided with the connecting portion of disc-shape respectively with same outer diameter as in described seat side arm and described backrest side arm portion, the dorsal part connecting portion can be rotated relatively with the chimeric one-tenth of seat side connecting portion, and the described dorsal part connecting portion after chimeric and the built-in described volute spring in inner space of described seat side connecting portion.