US3648004A

US3648004A - Auxiliary support means for electrical switch actuator

Info

Publication number: US3648004A
Application number: US118819A
Authority: US
Inventors: Robert C Williams
Original assignee: Cutler Hammer Inc
Current assignee: Cutler Hammer Inc
Priority date: 1971-02-25
Filing date: 1971-02-25
Publication date: 1972-03-07
Anticipated expiration: 1989-03-07
Also published as: GB1331926A

Abstract

A miniature precision snap action switch having a one-piece stressed blade contactor biased to a first position and operable to a second position by depression of an operator plunger, is provided with a lever actuator pivotally mounted in one of two recesses provided therefore in the housing to extend across the unused recess and the plunger to normally rest on the plunger. A resilient pad is positioned on the housing between the plunger and the pivoted end of the lever to support the lever in a position raised off the plunger whereby the pad must be initially compressed before the lever may engage the plunger. The pad is retained on the housing by a portion depending into the unused recess and shaped for retentive engagement therewith.

Description

United States Patent Inventor: Robert C. Williams, 111, Smithfield, N.C.

Cutler-Hammer, Inc., Milwaukee, Wis.

Feb. 25, 1971 Assignee:

Filed:

Appl. No.2

References Cited UNITED STATES PATENTS 8/1953 Lester ..74/107 X 11/1948 Repka..... 12/1970 Krieger ..200/67 D 6/1950 Kaminky et a1. ..200/172 A X Williams, 111 51 Mar. 7, 1972 i [54] AUXILIARY SUPPORT MEANS FOR 2,547,765 4/1951 Lund ..200/172 A ELECTRICAL swr'rcii ACTUATOR 2,817,725 12/1957 Rochfort etal ..200/47 Primary Examinerl-l. 0. Jones Attorney-Hugh R. Rather and William A. Autio [57] ABSTRACT A miniature precision snap action switch having a one-piece stressed blade contactor biased to a first position and operable to a second position by depression of an operator plunger, is provided with a lever actuator pivotally mounted in one of two recesses provided therefore in the housing to extend across the unused reees and the plunger to normally rest on the plunger. A resilient pad is positioned on the housing betwem the plunger and the pivoted end of the lever to support the lever in a position raised off the plunger whereby the pad must be initially compressed before the lever may engage the plunger. The pad is retained on the housing by a portion depending into the unused recess and shaped for retentive engagement therewith.

2 Claims, 3 Drawing Figures AUXILIARY SUPPORT MEANS FOR ELECTRICAL SWITCH ACTUATOR BACKGROUND OF THE INVENTION This invention relates to integral switch actuators for miniature precision snap action switches. More particularly this invention relates to auxiliary means for supporting such switch actuators.

Miniature precision snap action switches of the type described and claimed in the A. W. Krieger US. Pat. No. 3,548,]32 dated Dec. 15, 1970 and assigned to the assignee herein, comprise an overcenter snap action contact mechanism operable in response to very small increments of movement of an operator plunger. As denoted by the term miniature, the switches are physically small and their operator plungers and operating forces are accordingly small. To afford greater utility to the switches, various actuators are provided to increase the operator responsive area, to establish greater amounts of overtravel and to alter the operating force. A common actuator is a lever pivotally mounted to the housing to bear upon the plunger. The length of the lever may vary physically or it may be changed by relocating the pivot, or mounting point on the housing relative to the plunger and to this end a plurality of mounting points are often provided on the switch housing. Occasionally the actuator force requirements of an application are greater than may be achieved by moving the lever to the furthest mounting point from the plunger. Additionally, the actuating motion on the lever may be such as to impart a relatively sharp impact and release to cause the lever to vibrate freely wherein it may strike the operator sufficiently hard to cause false contact operation. The present invention provides a direct and economical solution to these problems.

SUMMARY OF THE INVENTION It is therefore a primary object of this invention to provide a means for increasing the actuator force ofa lever actuator for a miniature precision snap action switch.

It is a further object of this invention to provide a means for damping the motion of a lever actuator for a miniature precision snap action switch to prevent false contact operation by vibration of the lever actuator. It is still a further object of this invention to provide a resilient means having a portion thereof interengaging with a portion of the housing of a lever actuated miniature precision snap action switch to position said resilient means under the lever to increase the actuating force and dampen the vibratory motion of the lever.

These and other objects and advantages of this invention will become more apparent in the following specification and claims, when read in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is an isometric view of the resilient auxiliary support of this invention;

FIG. 2 is a side elevational view of a lever actuated miniature precision snap action switch having the cover removed therefrom and showing the auxiliary support member of FIG. 1 positioned below the lever actuator; and

FIG. 3 is a view identical to FIG. 2 but showing the switch in the actuated position.

DESCRIPTION OF THE PREFERRED EMBODIMENT The auxiliary support member 2 of this invention is shown isometrically in FIG. 1. The member 2 is formed of a resilient material such as rubber or the like and comprises a block, or main body portion 2a having a bevelled upper surface 2b. A leg portion 20 depends from the main body 2a at the lower end thereof, the leg portion 20 terminating in a foot portion 2d formed along its lower edge.

In FIG. 2, the auxiliary support member 2 is shown mounted on a miniature precision snap action switch 4. The latter includes a housing comprising an insulating base 6 from which an insulating cover has been removed to expose an internal cavity of the base 6 defined by end walls 6a and 6b and upper and

lower walls

6c and 6d, respectively.

Switch 4 is a single pole double throw device and has a pair of

terminals

8 and 10 mounted in the end wall 6b. The inner ends of

terminals

8 and 10 have contact elements 80 and10a, respectively secured to the adjacent surfaces thereof in vertical alinement. A- common terminal 12 is mounted in the lower wall 6d and is further secured at its upper end within a groove in the interior of upper wall 66. A one-piece stressed blade contactor 14 has a pair of contact elements 140 attached to the opposite sides at one end thereof, that end being positioned between the

contacts

8a and 10a. A pair oflateral compression elements 14b (only one of which may be seen in the drawings) are formed upwardly from the contactor blade to extend toward the left in FIG. 2 and the left-hand end of the contactor blade is formed in a reverse bent compression portion 140.

The contactor is attached to the common terminal 12 by bowing the compression elements 14b to enable the free ends thereof to seat within cooperating notches in terminal 12 at a point P while the free end of compression portion 14c is formed with a small projection to be received in a cooperating opening in terminal 12 to position the end of portion 140 against the terminal 12. The contactor 14 is shown in the nor mal assembled conditioned in FIG. 2 wherein the contactor blade lies above the point P to bias the right-hand end of the contactor. upwardly, effecting engagement between upper contact element 14a and contact element 8a.

An operator plunger 16 is positioned within an opening in upper wall 60 of base 6 to rest upon the left-hand end of contactor l4. Inward movement of the plunger 16 drives the lefthand end of contactor l4 downward to move the blade below the point P, thereby causing the right-hand end of the contactor to move downward with a snap action to effect engagement of the contact element 14a with contact element 10a as seen in FIG. 3. As may be seen when comparing FIGS. 2 and 3, the contact operation takes place in response to a relatively small amount of plunger travel, and that an equal or greater amount of plunger travel remains as permissable overtravel before the plunger would be stopped by ledge 6e in the base 6 and a similar ledge in the cover.

Switches of the aforedescribecl type are often provided with an integral lever actuator to provide greater actuator area, vary the actuating force required to operate the contact mechanism and generally broaden the utility of the switch. To this end, a pair of

identical recesses

6f and 6g are provided in the upper wall 60 of base 6, the recesses having a reduced area opening to the upper exterior surface of the base. A depression 6): is provided in the sidewall of each recess and similar depressions are provided in the housing cover to receive the outwardly projecting tabs 18a ofa lever 18 to pivotally mount the lever 18 to the switch housing in assembly of the switch.

As seen in the drawings, the lever 18 extends upwardly through the reduced area opening of the recesses 6g and then is formed over to project beyond the left-hand end of the switch housing, overlying the operator plunger 16. The plurality of

recesses

6f and 6g permits a choice of lever locations I in assembly of the switch, the recess 6g furthest from the operator providing an actuator requiring greater actuating force than that of the same lever mounted in the recess 6f nearest the operator plunger.

Occasionally switch applications require a greater actuator force then may be obtained with the lever 18 mounted in the recess 6 but the economics of the application place severe limitations upon the solutions. The auxiliary support member 2 provides a direct and inexpensive solution to this situation. As can be seen in FIG. 2 the member 2 supports the lever 18 upon the bevelled upper surface 2b of main body portion 2a in a position wherein the lever is raised off the plunger 16, thereby requiring initial compression of theresilient body portion 2a before the operator plunger is depressed and further compression during depression of the plunger to the switch operated position shown in FIG. 3. The amount of force to be added by the compression of the auxiliary support 2 may be varied by selecting materials having different resilient qualities for the support member.

The support member 2 solves the economic problems of the application particularly well in that it utilizes entirely an existing feature of the switch for attachment thereto and does not require additional fastening procedures or apparatus. The leg portion 2c and integral foot portion 2d may be seen to be complementally shaped to the outline of

recesses

6f and 6g to firmly retain the support member 2 to the switch housing when the leg portion and foot portion 2d are pressed into the recess 6f.

Support member 2 also solves another application problem wherein the actuating force imparted to the lever is severe and is followed by a quick release of the lever to cause the lever to vibrate freely. Since contact operation occurs at a relatively small amount of operator plunger travel, vibration of the lever can depress the plunger an amount sufficient to cause a false contact operation. By initially supporting the lever 18 in a raised position off the plunger 16, the support member 2 further moves to absorb the vibration of the lever without permitting it to touch the plunger 16 Thus there is provided herein an auxiliary support member for a lever actuated miniature precision snap action switch which may be readily attached to the switch to provide additional actuating force for the lever actuator and to dampen the vibration of the actuator and thereby prevent false contact operation due to such vibration. The amount of additional force to be provided may be readily varied by selecting a material of greater or lesser resiliency for the support member.

l claim:

1. In a miniature precision snap action switch, the combination comprising:

insulating housing means;

snap action contact means in said housing means;

operator means extending through one side of said housing means to operate said contact means; a plurality of recesses in said one side of said housing means in serially spaced relationship from said operator means;

lever actuator means pivotally mounted to said housing means in one of said recesses and overlying said operator means;

auxiliary support means for said lever actuator means, said Support means having an integral portion extending into one of said recesses between said operator means and the recess in which said lever actuator means is mounted, said integral portion being in retentive engagement with portions of said housing means defining said recess to attach said support means to said housing means; and

wherein said support means is formed ofa resilient material and extends above said one side of said housing means to support said lever actuator means in a raised position relative to said operator means and require and support means be initially compressed by said lever actuator means before the latter engages said operator means.

2. The combination according to claim 1 wherein said recesses are formed to have a reduced area opening to said one side relative to the inner portion of the respective recess and said integral portion of said support means is formed to have an enlarged lower portion which in the noncompressed state is larger than the reduced area opening of the respective recess.

Claims

1. In a miniature precision snap action switch, the combination comprising: insulating housing means; snap action contact means in said housing means; operator means extending through one side of said housing means to operate said contact means; a plurality of recesses in said one side of said housing means in serially spaced relationship from said operator means; lever actuator means pivotally mounted to said housing means in one of said recesses and overlying said operator mEans; auxiliary support means for said lever actuator means, said support means having an integral portion extending into one of said recesses between said operator means and the recess in which said lever actuator means is mounted, said integral portion being in retentive engagement with portions of said housing means defining said recess to attach said support means to said housing means; and wherein said support means is formed of a resilient material and extends above said one side of said housing means to support said lever actuator means in a raised position relative to said operator means and require and support means be initially compressed by said lever actuator means before the latter engages said operator means.