US3789173A

US3789173A - Alternate action switch convertible to momentary by putting latch on different pivot

Info

Publication number: US3789173A
Application number: US00312901A
Authority: US
Inventors: G Bury
Original assignee: Illinois Tool Works Inc
Current assignee: Illinois Tool Works Inc
Priority date: 1972-12-07
Filing date: 1972-12-07
Publication date: 1974-01-29
Anticipated expiration: 1991-01-29
Also published as: JPS4988083A; CA970011A; BR7302669D0; CH589932A5; FR2209995A1; SU562224A3; IT992571B; GB1442590A; NL7304621A; DE2322798A1

Abstract

A switch has movable contacts that are actuated by a rotatable ratchet that is operated by push button-driven pawl. The ratchet cooperates with a spring-biased, pivoted lever for providing alternate switch operation in which the ratchet is moved with a toggle action to either of two positions and latched thereat. The pivot axis of the lever may be optionally shifted so that the lever will apply force against the ratchet in a manner to bias it to only one position to provide a momentary switch operation. The pawl is integral with a carrier and is joined there to by torsion spring connections at which the pawl rotates upon its actuation of the ratchet.

Description

linited States Patent 1191 Bury 1,916,360 7/1933 Crane 200/153 J UX Primary Examiner-Robert K. Schaefer Assistant ExaminerR0bert A. Vanderhye [75] Inventor: George John Bury, Lake Villa, Ill. Attorney, Agent or Firm Roy H. Olson et a]. [73] Assignee: Illinois Tool Works Inc, Chicago,

' I1]. [57] ABSTRACT [22] Filed; 7 1972 A switch has movable contacts that are actuated by a rotatable ratchet that is operated by push button- PP Flo-13121901 driven pawl. The ratchet cooperates with a springbiased, pivoted lever for providing alternate switch 52 us. (:1. 200/153 J in which the ratchet is mved with wggle 511 Int. Cl. 110111 13/60 achm either Positions and latched themat- [58] Field 01' Search 200/153 J 169 PB The Pivot axis lever may he Pfiha11Y Shifted that the lever will apply force against the ratchet in a 56] References Cited manner to bias it to only one position to provide a momentary switch operation. The pawl is integral with a UNITED'STATES PATENTS carrier and is joined there to by torsion spring conneci 'tions at which the pawl rotates upon its actuation of C a OW 3,274,354 9/1966 Stevens 200/153 J ux the ratchet 2 3,288,973 11/1966 Piber 200/153 J X 9 Claims, 9 Drawing Figures I: 45 15 I? J6 51? 74 2 74' 1 /Ag 0 I I: 54 r /6 2/ 5a GA m 0: gz n .105 /Z4 2 1100 2%19' c :II '7 5 c J L; 2 20 hi I" g ALTERNATE ACTION SWITCH CONVERTIBLE TO MOMENTARY BY PUTTING LATCH ON 1 DIFFERENT PIVOT BACKGROUND OF THE INVENTION This invention relates to an improvement in switches of the type capable of selectively providing either alternate or momentary switch operation.

A switch of the foregoing type is advantageous in that a single mechanism can be used, which mechanism can be placed in either of two operating modes. In one mode alternate operation is provided by a mechanism that can be toggled or snapped over-center upon depression of a push-button. In another mode momentary operation is provided in that the mechanism is biased to one position only. When the mechanism is shifted to the other position by the push-button, the mechanism stays in that position only so long as the push-button is held.

OBJECTS AND SUMMARY OF THE INVENTION An object of this invention is to provide a switch of the foregoing type in which the operating mode, namely alternate action or momentary action, can be changed by simply shifting the position of a lever that forms part of the switch contact actuating mechanism whereby the lever serves to latch the mechanism in the alternate action mode but is unlatched from the mechanism in the momentary action mode and tends to bias the mechanism to only one position.

A further object of this invention is to provide a switch that has a push button operated carrier that integrally includes a pawl for operation of a ratchet that forms part of the switch mechanism, the pawl being integrally connected to the carrier by spaced bridges of material that form torsion spring connections, whereby the pawl rotates about an axis passing through those bridges when the pawl engages the ratchet for operation of the same. a

A still further object of this invention is to provide a switch of the type and for the purpose stated in which a lamp is housed within the push button, and wherein the lamp is adapted to remain illuminated when the push button is either in its actuated or non-actuated position.

In accordance with the foregoing objects the switch comprises a housing with at least one fixed switch contact and at least one movable switch contact; however, in the form of the invention to be described there are four fixed and two movable contacts to provide two simultaneously operable double-pole, double-throw switches. A contact-actuating mechanism includes a ratchet rotatable in the housing and having a camming surface adapted to bear against the movable contact or contacts. A carrier is in the housing and has a pawl movable toward and away from the ratchet, the pawl being preferably T-shaped and being joined to said carrier by bridges of material that form torsion springs. A spring-biased lever in the housing is mounted in one operative position at which it is pivotally supported by spaced trunions. The lever has a latching nose for engagement with the ratchet at notched regions of the ratchet to latch the ratchet in either of two selected positions to which the ratchet may be shifted by a toggle action. The housing has an opening for access to the lever and by which the lever may be shifted to a second position of pivotal support on the trunions so that the latching nose of the lever may then engage the ratchet at other regions and in a non-latched condition. In this non-latched condition the lever biases the ratchet toward only one position, this bias being overcome only so long as the push button is depressed to rotate the ratchet to another position.

BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a perspective view of a switch constructed in accordance with and embodying the present invention;

FIG. 2 is a fragmentary sectional view, on an enlarged scale, taken along line 22 of FIG. 1;

FIG. 3 is a fragmentary perspective view of the carrier that forms part of the present invention and being shown with the lamp bulb terminals assembled therewith;

FIG. 4 is a fragmentary sectional view taken approximately along line 4l4 of FIG. 2;

FIG. 5 is an exploded perspective view of the base assembly and associated mechanism that forms part of the switch and with certain parts broken away for purposes of clarity;

FIG. 6 is a fragmentary sectional view of a part of the structure in FIG. 2 but on an enlarged scale and showing the mechanism set for operation in the alternate action mode and being in one of two positions thereof;

FIG. 7 is a view similar to FIG. 6 and showing the other position of the alternate action mode;

FIG. 8 is a sectional view similar to FIGS. 6 and 7 but showing the mechanism set for operation in the momentary action mode and with the push button and pawl retracted from the ratchet; and

FIG. 9 is a sectional view similar to FIG. 8 and showing the pawl engaging the ratchet as would be the case in the momentary action mode when the push button is depressed.

DETAILED DESCRIPTION Referring now in more detail to the drawings there is shown a switch 2 having a housing 4 that includes at its lower end a base 6. The base 6 is of generally rectangular configuration and has an upstanding ledge 8 that telescopes within the open bottom of the housing 4. The housing 4 and base 6 are each formed of a suitable plastic material, and the two may be secured together in any suitable manner. The housing 4 is of generally rectangular cross section but at its upper end there is a cylindrical stem 10. The stem 10 has an external thread for receiving a nut (not shown) so that the switch housing 4 may be mounted on a panel or the like.

Mounted in and projecting through the base 6 is a series of electrical terminals, there being eight such terminals in the present form of the invention. More particularly, adjacent to one edge of the base are three terminals l2, l4, l6, and adjacent to the opposite edge of the base are

similar terminals

12a, 14a, 16a. Each group of terminals provides a single-pole, double-throw switch. Terminal 16 is bent at one end to provide a fixed switch contact 18 while terminal 14 is bent at one end to provide another fixed switch contact 20. Terminal 12 carries a spring blade that serves as a movable contact 22 and which is actuated by mechanism hereinafter more fully described. Corresponding contacts are present on the terminals 12a, Ma, 16a. Also provided on the base 2 and intermediate the aforesaid groups of from the base. The

lamp terminal

24, 26 are connected to a lamp power supply for purposes presently more fully appearing.

Mounted for reciprocation within the upper end of the housing 4 is a push button 28 that includes a plunger 30 and a cap 32, the plunger 30 extending through the opening 34 in the upper end of the stem 10. As best seen in FIG. 2, the plunger 30 is formed with opposed longitudinal slots 36, 38, the slot 36 having a detent 40 near its upper end. The detent 40 is adapted to engage a shoulder 42 in the stem to retain the push button 28 assembled with the housing. In this regard it should be noted that the shank of the plunger 30 will, by reason of the presence of the slots 36, 38, be capable of being radially 60 to permit the leading tapered end of the plunger to be inserted into the 13 34 after which the plunger will resiliently expand to provide the radial overlap between the detent 40 and the shoulder 42.

Telescoped within the plunger 30 is a conventional lamp bulb 44 having

contacts

46, 48 which are in series with the filament within the lamp bulb. A resilient secondary lamp terminal 50 projects through the slot 38 and engages the annular lamp contact 46. An additional resilient secondary lamp terminal 52 of generally L-shape engages the central or axial lamp contact 48. The lower ends of the

terminals

50, 52 are in abutting engagement with push

button return springs

54, 56, the

return springs

54, 56 also receiving and being in abutting contact with the

lamp terminals

24, 26. Electrical continuity is maintained through the

springs

54, 56 to the lamp bulb 44 regardless of whether or not the push button 28 is in its depressed or released position so that the lamp bulb 44 will remain on as long as power is supplied to the

terminals

24, 26.

Also mounted within the housing 4 and below the stem 10 is a molded plastic carrier 58 that is of generally rectangular shape having a central downwardly opening cavity 60 (FIG. 4). The carrier 58 has opposed

side walls

62, 64 each of which has a slot 66 for receiving one of the

return springs

54, 56. As best seen in FIG. 3, the upper end of the slot 66 terminates in a widened part 68 that receives the terminal 50 and wherein the terminal bears against abutments 70. A thinned out tongue 72 of the terminal telescopes within the return spring. The top wall of the carrier 58 also has a slot 74 for receiving the terminal 50 whereby the terminal 50 is anchored in the carrier 58. The side wall 64 and the adjacent part of the top wall of the carrier is similarly constructed for receiving and retaining the terminal 52, and therefore includes a slot 74 (FIG. 3) in the top wall of the carrier and a widened part 68' (FIG. 2) for receiving the lower portion of the terminal 52.

The other pair of opposed side walls 76, 78 of the carrier are formed with

vertical slots

80, 80 that are received in

ribs

82, 82 that project inwardly from two opposed walls of the housing 4. This provides, in effect, a pair of opposed rails for guiding the reciprocating movement of the carrier 58 which, as will now be apparent, is movable with the push button 28 in opposition to the return springs 54, 56.

Depending from the end or top wall 83 of the carrier 58 is a pawl 84 which is joined to the top wall by spaced bridges 86, 86 (FIG. 4) of the plastic material of the carrier. These spaced bridges 86, 86 are effectively provided by reducing the thickness of the top wall as shown by the arcuate recesses 88 appearing in FIG. 4. In addition, the wall 83 is formed with slots 90, 90 (FIG. 3) on opposite sides of the pawl 84 and extending between the

bridges

86, 86. Thus, the pawl 84, as viewed in FIG. 4, is a generally T-shaped element with the ends of the T being joined to the carrier by the spaced bridges 86, 86. These bridges define torsion bars to provide a torsion spring connection between the pawl 84 and the carrier. When force is applied to the pawl 84 tending to bend it left or right (FIG. 2) the pawl will not be significantly bent transversely. On the contrary, the pawl will remain substantially straight as seen by the broken line position of the pawl in FIG. 2. However, the pawl will pivot about the axis 92 in opposition to the torsion springs formed by the

bridges

86, 86, and for purposes presently more fully appearing.

Integrally provided on the base 6 somewhat centrally thereof are

upstanding trunions

94, 94 for receiving a journal pin 96. A ratchet 98 rotates on the journal pin 96 for movement about the pin axis 100. The ratchet 98 has a central portion that lies between the

trunions

94, 94. This central portion has converging

surfaces

102, 104 and spaced apart ratchet

teeth

106, 108. Laterally outwardly of the

trunions

94, 94 the ratchet 98 has camming surfaces 110, for respective engagement with the

movable contacts

22, 22. In the form of the invention herein shown and described, the

movable contacts

22, 22 are, as a result of their normal spring bias, in engagement with the

contacts

18, 18 when the ratchet 98 is in the position shown in FIGS. 2, 6 and 8, and in which position the camming surfaces 110 are slightly spaced from the

movable contacts

22, 22. On the other hand, when the ratchet 98 is moved to the position shown in FIG. 7 or FIG. 9, the camming surfaces 110 depress the

movable contacts

22, 22 causing them to engage their

respective contacts

20, 20.

Positioned below the central portion of the ratchet 98 and intermediate the

trunions

94, 94 is a latching lever 112. At one end the latching lever 112 rigidly receives a pin 114 that extends laterally of the latching lever 112 for pivotal disposition in the

trunions

94, 94. For this purpose the

trunions

94, 94 have, as best seen in FIG. 5, two pairs of aligned

notches

116, 116 and 118, 118. The pin 114 is sized for rotatable seating selectively in either the

notches

116, 116 or the

notches

118, 118 for pivotally supporting the lever about spaced parallel axes, one axis being for each operative position. Adjacent to the forward end 120 of the lever 112 is a downwardly opening annular recess 122 for retentively receiving the end portion of a coil spring 124. The coil spring 124 also bears against the inside surface of the base 6 and tends to bias the latching lever 112 for clockwise rotation (as illustrated herein) about the axis of the pivot pin 114 whether the latter is in the

notches

116, 116 or in the

notches

118, 118.

In order to shift the position of the lever from one set of

notches

116, 116 to the other set of notches 118, 1 18 and/or back again, the base 6 has an elongated access opening or slot 126 for receiving a small diameter pin, wire, or other small tool. This tool can be inserted into a blind hole 128 in the bottom of the lever 112 for manipulation of the lever 112. Thus, with the tool in the hole 128 the lever can be lifted so that the pin 114 is removed from the notches 116 as in FIGS. 6 and 7, and shifted by the tool to the left for seating in the

notches

118, 118, as shown in FIGS. 8 and 9. The reverse procedure may be carried out in a like manner, and in each instance the lever is shifted with the coil spring 124. The pin 114 is readily reseated in the pair of notches to which it is shifted because the force of the lever 112 against the ratchet due to the spring 124 tends to urge the pin 124 downwardly toward the

notches

116, or 118, as the case may be.

The lever 112 has an upwardly presented, generally triangular latching nose 130 for engagement with the underside of the ratchet at predetermined regions depending upon whether or not the lever is in the notches 116 or the notches 118. This, in turn, determines whether or not the switch is in the alternate action mode or in the momentary action mode. FIGS. 6 and 7 show the mechanism in the alternate action mode, and in this mode the lever pin 114 is in the

notches

116, 116. The central part of the ratchet has two spaced apart latching

notches

132, 134 for engagement by the latching nose 130 in either of two positions in which the ratchet has been shifted by a toggle action. Thus, in FIG. 6 where the ratchet is in one position the latching nose 130 engages the notch 132; in the other position the latching nose 130 engages the notch 134.

If, however, the lever 112 is shifted so as to be seated in the

notches

118, 118, as shown in FIGS. 8 and 9, the lever 112 will be in a position such that the switch mechanism is in the momentary action mode. In such case one surface of the latching nose 130 will bear against an intermediate surface 136 (FIG. 8) on the ratchet that is located between the

notches

132, 134. As the ratchet 98 moves from the position shown in FIG. 8 to that shown in FIG. 9, the pointed end of the latching nose 130 initially engage the notch 134 and then engages the bottom surface portion 138 of the ratchet beyond the notch 134.

In operation in the alternate action mode, assume that the ratchet 98, the latching lever 112, and associated parts are in the positions shown in FIG. 6. As the push button 28 is depressed, the tapered end of the pawl 84 will engage the surface 102, pushing thereagainst until thhe pawl pivots about the axis of its torsion springs and finally engages the ratchet tooth 106. Pressure against the tooth 106 causes the ratchet to rotate counterclockwise about the pivot axis 100 until the ratchet is over center or over toggled with respect to the axis 100. Rotation of the ratchet 98 forces the latching nose 130 out of the latching notch 132. When the ratchet has rotated past dead center, the latching nose 130 will then be past the dead center apex 140 of the ratchet. Therefore, the spring 124 will cause the latching nose 130 to apply force to the ratchet along a line to the right (FIGS. 6 and 7) of the axis 100. This causes the ratchet to snap into the position shown in FIG. 7 and with the latching nose 130 now locking the ratchet by reason of engagement in the latching notch 134. The ratchet remains in the position shown in FIG. 7 after the push button is retracted. To shift the ratchet from the position shown in FIG. 7 back to the position shown in FIG. 6 the push button is depressed causing the pawl 84 to deflect as shown in broken lines (see FIG. 2) and engage the ratchet tooth 108. The ratchet is then toggled over center causing the latching nose 130 to apply force to the ratchet along a line to the left of the axis 100. The latching nose 130 then snaps into the latching notch 132 to lockthe ratchet in position.

With the mechanism in the momentary action mode, shown in FIGS. 8 and 9, the pawl 84 engages the surface 102 and ratchet tooth 106 each time the push button 28 is depressed. This always rotates the ratchet counterclockwise to move it to the position shown in FIG. 9. However, the line of force applied by the spring biased latching nose 130 is always to the left of the axis causing the ratchet to be biased in a counterclockwise direction. Thus, when the push button 28 is released, this counterbiasing of the spring 124 returns the ratchet to the position shown in FIG. 8.

The invention is claimed as follows:

1. In combination, switch contact actuating means, and means for effecting movement of said actuating means, said means comprising a carrier and a pawl integrally joined to said carrier and engageable with said actuating means, the integral joint of the pawl with the carrier constituting at least one bridge of resilient material that forrns a torsion spring and surrounds a pivot axis at which the pawl rotates without significant longitudinal bending upon engagement with said actuating means, a base; said actuating means including a ratchet pivotally mounted on said base and engaged by said pawl, and means cooperating with said ratchet to locate the ratchet for selective movement between two positions with a toggle action or optionally to locate the ratchet for movement between two positions with said ratchet being biased toward only one of said last-named two positions; said last-named means comprising a lever, and means for optionally mounting the lever for movement about either of two pivot axes relative to said base.

2. A switch having a switch contact with first and second positions, and actuating mechanism operable in a first mode for moving said contact from each position to the other position with a toggle action and operable in a second mode for moving said contact from the first position to the second position in opposition to a force tending to bias said contact to said first position; said mechanism including rotatable means operable in said first mode for toggling to each of two positions corresponding to said first and second contact positions, latching means operable in said first mode for engaging predetermined latching regions of said rotatable means for retaining said rotatable means in the position to which it has been toggled, and means by which the position of the latching means may be shifted for operation in said second mode, said latching means in said second mode engaging said rotatable means in other predetermined regions and at which said latching means remains unlatched from said rotatable member and imposes a force on said rotatable member tending to bias it only to its first position; said latching means comprising a lever, spring means biasing said lever against said rotatable means, and means forming discrete pivotal supports for different positions of the lever in the respective modes.

3. A switch comprising a housing, at least one fixed contact and at least one movable switch contact in said housing, a ratchet rotatable in said housing and having a camming portion for bearing against said movable contact, a carrier in said housing and having a pawl movable toward and away from said ratchet, a springbiased lever mounted in one operative position in said housing and having means for latching engagement with said ratchet at predetermined regions to latch the ratchet to either of two selected positions to which said ratchet has been shifted by said pawl and in which in one of said positions said camming portion has urged said movable contact into engagement with said fixed contact, means for mounting said lever in a second operative position in which the lever is wholly displaced from said one operative position, said lever in said second operative position having said latching means displaced from said predetermined regions for nonlatching engagement with said ratchet as the latter is shifted by said pawl to move said movable contact into engagement with said fixed contact such that the spring bias of the lever moves the movable contact away from the fixed contact upon retraction of said pawl from said ratchet.

4. A switch according to claim 3 in which said housing has an opening for access to said lever to shift the same selectively for mounting in either of its two operative positions.

5. A switch according to claim 4 in which said housing has means for pivotally supporting the lever for movement about spaced parallel axes, one axis being for each of said two operative positions.

6. A switch according to claim 3 in which said predetermined regions are notches in the ratchet and said means for latching is a nose member on said lever.

7. A switch according to claim 4 in which said lever has a hole exposed to said opening for engagement by a tool for manipulating said lever.

8. A switch according to claim 3 including a push button for actuating said carrier, spring means biasing said push button and carrier to a non-actuating position away from said ratchet, a lamp bulb within said push button, and lamp bulb terminals engaging said lamp to provide a circuit therethrough.

9. A switch according to claim 8 wherein said lamp bulb terminals are electrically connected to said spring means to maintain electrical continuity through said lamp bulb in the actuated or non-actuated position of the push button.

Claims

1. In combination, switch contact actuating means, and means for effecting movement of said actuating means, said means comprising a carrier and a pawl integrally joined to said carrier and engageable with said actuating means, the integral joint of the pawl with the carrier constituting at least one bridge of resilient material that forms a torsion spring and surrounds a pivot axis at which the pawl rotates without significant longitudinal bending upon engagement with said actuating means, a base; said actuating means including a ratchet pivotally mounted on said base and engaged by said pawl, and means cooperating with said ratchet to locate the ratchet for selective movement between two positions with a toggle action or optionally to locate the ratchet for movement between two positions with said ratchet being biased toward only one of said last-named two positions; said last-named means comprising a lever, and means for optionally mounting the lever for movement aBout either of two pivot axes relative to said base.

3. A switch comprising a housing, at least one fixed contact and at least one movable switch contact in said housing, a ratchet rotatable in said housing and having a camming portion for bearing against said movable contact, a carrier in said housing and having a pawl movable toward and away from said ratchet, a spring-biased lever mounted in one operative position in said housing and having means for latching engagement with said ratchet at predetermined regions to latch the ratchet to either of two selected positions to which said ratchet has been shifted by said pawl and in which in one of said positions said camming portion has urged said movable contact into engagement with said fixed contact, means for mounting said lever in a second operative position in which the lever is wholly displaced from said one operative position, said lever in said second operative position having said latching means displaced from said predetermined regions for non-latching engagement with said ratchet as the latter is shifted by said pawl to move said movable contact into engagement with said fixed contact such that the spring bias of the lever moves the movable contact away from the fixed contact upon retraction of said pawl from said ratchet.