US3591750A

US3591750A - Stopper plate mounting for pushbutton switch

Info

Publication number: US3591750A
Application number: US19976A
Authority: US
Inventors: Masao Ohkita
Original assignee: Alps Electric Co Ltd
Current assignee: Alps Alpine Co Ltd
Priority date: 1969-04-10
Filing date: 1970-03-16
Publication date: 1971-07-06
Anticipated expiration: 1988-07-06

Abstract

A pushbutton switch comprises a pushrod having communicating vertical and longitudinal channels, the stopper plate against which the biasing spring is adapted to operate having downwardly extending arms with inwardly extending parts, the inwardly extending parts being passable through the vertical channels and then being movable along the longitudinal channels to the ends thereof under the influence of the biasing spring.

Description

O Unlted States Patent 1 1 3,591,750

[72] Inventor 'MasaoOhkita [56] References Cited Java" UNITED STATES PATENTS Q12; g 6 m0 2,156,946 5/1939 ClOSSOl'I e161 200/169 PB [45] Patented luly'6 2,433,710 12/1947 Schleicher ..200/166 BC (X) 2,524,215 10/1950 Wegehoft.... 200/172 A 2,811,617 10/1957 Townsend 200/166 13c Y 3,172,985 3/1965 De Smidt 200/172A Pmmy 1969 5 244 847 4/1966 E 1 200/172 R x [33] {Japan rpe 31 44/112,695 Primary Examiner-H. 0. Jones Attorney-James and Franklin ABSTRACT: A pushbutton switch comprises a pushrod hav- [54] S :EZ PLATE MOUNTING FOR PUSHBUTTON ing communicating vertical and longitudinal channels, the WI D stopper plate against which the biasing spring is adapted to 8 Chums 6 raw'ng operate having downwardly extending anns with inwardly ex- [52] U.S.Cl. ZOO/172R tending parts, the inwardly extending parts being passable [51] lnt.Cl H0lh through the vertical channels and then being movable along Field of Search 200/172, the longitudinal channels to the ends thereof under the in- 166 BC, 169 PB, 159 R fluence of the biasing spring.

STOPPER PLATE MOUNTING FOR PUSIIBUTTON SWITCH This invention relates to a pushbutton switch and more particularly to improvements in the mounting of the stopper plate on the pushrod of that switch.

The conventional pushbutton switch has a pushrod which is adapted to be moved in and out to actuate the switch, a biasing spring being operatively connected to that pushrod so as normally to urge it to its outward position. That spring acts on the pushrod by means of a stopper plate which is mounted on the pushrod. In the past the mounting of the stopper plate on the pushrod has involved a resilient action during the time that the stopper plate and pushrod are being assembled together. The thus-necessitated resiliency of the stopper plate has led to excessive cost, since when the stopper plate is made of resilient material it must be more expensive than if it were made of some rigid material. In addition, the resiliency of the material of which the stopper plate was made was in itself disadvantageous, since it presented a somewhat unsteady backing for the biasing spring. Moreover, the actual mounting of the stopper plate on the pushrod required the application of appreciable force onthe stopper plate, and this gave. rise to distortion of parts during the assembly operation.

It is the prime object of the present invention to eliminate these disadvantages by providing a rigid stopper plate which can readily be mounted on the pushrod and which, when thus mounted, will provide a reliable and effective element for engagement with the biasing spring.

It is a further object of the present invention to provide a pushbutton switch which has a reliable and relatively inexpensive construction.

In order to perform the above objects, the pushrod of the switch is formed with substantially vertical side channels and with substantially longitudinally extending channels communicating therewith. The stopper plate is provided with depending arms with inwardly extending parts, those parts being vertically movable through the vertical channels to the longitudinal channels and then being slidable along the longitudinal channels to the end walls of those latter channels. The biasing spring which is compressed between the switch body and the stopper plate proper urges the stopper plate to the position in which the inwardly extending parts reach and are. pressed against the ends of the longitudinal channels. Thus assembly of the parts is easily accomplished, no particular force need be exerted on the parts when they are assembled, the stopper plate is rigid and therefore provides a very firm and effective backing for the biasing spring, and the stopper plate may be made of relatively inexpensive material because it can be rigid.

To the accomplishment of the'above, and to such other objects as may hereinafter appear, the present invention relates to the mounting of a stopper plate on the pushrod of a pushbutton switch, as defined in the appended claims and as described in this specification, taken together with the accompanying drawings, in which:

FIG. 1A is a three-quarter perspective view of a portion of a pushbutton switch pushrod and the stopper plate adapted to be associated therewith according to the prior art;

FIG. 1B is a cross-sectional view of the assembled prior art structure of FIG. 1A, taken along the line 18-18 of FIG. 1A;

FIG. 2 is a three-quarter perspective view of a pushbutton switch body, pushrod, stopper plate and biasing spring assembly in accordance with the present invention;

FIG. 3A is a cross-sectional view taken along the line 3A-3A of FIG. 2;

FIG. 3B is a cross-sectional view taken along the line 3B-3B of FIG. 2; and

FIG. 4 is an exploded view of the assembly of FIG. 2, showing the stopper plate in position ready to be assembled and mounted onto the pushrod.

A pushbutton switch of the type here under discussion comprises a body generally designated A within which the switching elements and contacts are received. The internal structure of the body A, and the electrical and mechanical arrangement therein, form no particular part of the present invention, and therefore no details thereof are shown. A pushrod generally designated 8 extends from the body A and is adapted to be moved into and out from that body, thereby selectively to actuate the parts within the body so as to cause one type or another of electrical connection to be effectuated. The pushrod B is normally urged outwardly by a biasing spring generally designated C, that spring beingcompressed between -the body A and a stopper plate generally designated D which is mounted on the pushrod B.

FIGS. 1A and lB illustrate the established prior art method of mounting the stopper plate D on the pushrod B. In accordance with the 'prior art the pushrod B is provided with a pair of vertically extending channels 2 extending from the top wall 4 to the bottom wall 6 thereof. The stopper plate D is provided with an upper body portion 8 and depending arms 10, the space between the arms being substantially equal to the width of the pushrod B between the vertical channels 2 thereof. At the lower ends of the depending arms 10 are inwardly extending projections 12 which, as may best be seen from FIG. 1B, are adapted to snap beneath the lower surface 6 of the pushrod B. Inorder for this to occur the stopper plate D must be sufficiently resilient so that the arms 10 may spread apart as the stopper plate D is pushed down onto the pushrod B from its position shown in FIG. 1A to its position shown in FIG. 1B. This necessary resiliencyof the stopper plate Dv requires that the plate be formed of a relatively expensive material. Moreover, it is not feasible to make only the arms 10 resilient, and consequently all of the plate D is resilient. As-a result, when the biasing spring C engages with the stopper plate D, the stopper plate D is somewhat distorted or resiliently bent by the action of the biasing spring C, thus giving rise to unreliability of operation.

In order to eliminate these disadvantages, and as illustrated in FIGS. 2-4, the pushrod B of the present invention is provided with substantially vertically extending channels 2 which, at their lower ends, communicate with substantially longitudinally extending channels 14 in the pushrod B, those longitu:

dinally extending channels 14 extending from the lower ends of the vertical channels 2 in a direction away from the switch body A, there to terminate in end walls 16.

The stopper plate I) .comprises a body portion 18 from which arms 20 depend, those arms having inwardly extending parts. 22. at their lower ends. In contradistinction to the inwardly extending parts 12 of the prior art embodiment illustrated in FIGS. 1A and 1B, the inwardly extending parts 22 of the stopper. plate of the present invention terminate in facing substantially vertical surfaces 24 which are of appreciable height and which are substantially vertical, these surfaces 24 being adapted to cooperate with the sidewalls 26 of the longitudinally extending channels 14. The spacing between the surfaces 24 is thus seen to be approximately the same as the width of the mounting portion of the pushrod B between thevertically extending channels 2, that being designated by the arrows 28 in FIG. 4. The spacing between the arms 20 above the inwardly extending parts 22 is approximately equal to the overall width of the mounting portion of the pushrod B, as-indicated by the arrows 30 in FIG. 4. The vertical spacing between the body portion 18 of the stopper plate D and the inwardly extending parts 22 is substantially equal to the spacing between the upper surface of the pushrodB and the upper surfaces 32 of the longitudinally extending channels 14.

The biasing spring C is preferably helical in nature and surrounds the pushrod B. One end thereof engages the front face 34 of the switch body- A, and the other end thereof engages portions of the stopper plate D which extend out beyond-the pushrod B. As will be seen from the description of the assembly of the parts which follows, the stopper plate D may be made of rigid material, and preferably is so constructed.

Hence, it provides a very effective backing or stop for the biasing spring C, and reliably transmits the biasing force of that spring to the pushrod B.

To assemble the parts the biasing spring C is first placed over the pushrod B, moved into engagement with the face 34 of the switch body A, and compressed until it has moved to the right (as viewed in FIG. 4) beyond the vertically extending channels 2 in the pushrod B. Then, while the biasing spring C is retained in that compressed condition, the stopper plate D is moved downwardly from its position shown in FIG. 4, the inwardly extending parts 22 thereof entering into and sliding down through the vertical channels 2, but without any distortion of the stopper plate D. When the stopper plate D has moved down as far as it can go, with its body portion 18 resting on the upper surface of the pushrod B, the inwardly extending parts 22 will be in registration with the right-hand ends of the longitudinally extending channels 14. At this point the biasing spring C may be released. [twill tend to expand and will engage the stopper plate D, pushing the latter to the left as viewed in FIG. 4. Under the action of the biasing spring C the stopper plate D will move to the left, its inwardly extending parts 22 sliding along the longitudinal channels 14 and its arm 20 sliding along the side surfaces of the pushrod B, until the inwardly extending parts 22 reach the end walls 16 of the longitudinal channels 14. At that point the spring-urged movement of the stopper plate D relative to the pushrod B will cease, and thereafter the resilient force of the biasing spring C will be exerted rigidly through the stopper plate D to the pushrod B, retaining that pushrod B in its outer position until it is manually pushed inwardly. The surfaces 24 of the inwardly extending parts 22 on the stopper plate D essentially mate with and ride along the surfaces 26 of the channels 14, thus steadying and guiding the stopper plate D on the pushrod B and preventing relative rotation of those parts.

From the above it will be seen that the stopper plate D of the present invention need not be, and preferably is not, resilient, and hence it may be manufactured at a lower cost than has previously been thought feasible. Moreover, the assembly of the parts is greatly facilitated, no force need be ex erted in the course of the assembly, and consequently damage to the parts and subsequent rejection of the assemblies is minimized.

While but a single embodiment of the present invention has been here specifically disclosed, it will be apparent that many variations may be made therein, all within the scope of the invention as defined in the following claims.

lclaimz.

1. A pushbutton switch comprising a body, a pushrod movable into and out from said body, said pushrod having a mounting portion comprising an upper section having a predetermined width and a lower section having a lesser width and defining with said upper section substantially longitudinally extending channels terminating in end walls at those ends of said longitudinal channels directed away from said body, said mounting portion having substantially vertical side channels open at the top and communicating with said longitudinally extendingchannels respectively at those ends of said longitumounted on and extending from said pushrod and having depending arms with inwardly extending parts, said arms being spaced from one another by a distance no less than said predetermined width, said parts being spaced from one another by a distance less than said predetermined width and no less than said lesser width, said vertical side channels being of a size to accommodate said inwardly extending parts, and a spring active between said body and said stopper plate and effective to urge said stopper plate away from said body, said inwardly extending parts then being urged into engagement with said end walls of said longitudinal channels.

2. The switch of claim 1, in which said stopper plate is essentially rigid.

3.'The switch of claim 2, in which the opposing portions of said inwardly extendin parts are defined by surfaces of appreciable height, said ongitudinally extending channels having walls of appreciable height against which said portion surfaces are engaged.

4. The switch of claim 1, in which the opposing portions of said inwardly extending parts are defined by surfaces of appreciable height, said longitudinally extending channels having walls of appreciable height against which said portion surfaces are engaged.

5. A pushbutton switch comprising a body, a pushrod movable into and out from said body, said pushrod having a pair of opposed open-topped vertically extending channels in opposite sides thereof, and a pair of longitudinal channels communicating with said vertical channels respectively at their lower ends, extending therefrom in a direction away from said body, and terminating in end walls, a stopper plate comprising a body portion adapted to extend from said pushrod, a pair of arms depending from said body portion and spaced from one another by a distance substantially equal to the width of said rod, and a pair of inwardly extending parts on said arms spaced below said body, said parts being passable through said vertical channels and slidable along said longitudinal channels while said body portion of said stopper plate is above said pushrod, and a spring active between said body and said stopper plate and effective to urge said stopper plate away from said body and said inwardly extending parts into engagement with said end walls of said longitudinal channels.

6. The switch of claim 5, in which said stopper plate is essentially rigid.

7. The switch of claim 6, in which the opposing portions of said inwardly extending parts are defined by surfaces of appreciable height, said longitudinally extending channels having walls of appreciable heightagainst which said portion surfaces are engaged.

8. The switch of claim 5, in which the opposing portions of said inwardly extending parts are defined by surfaces of appreciable height, said longitudinally extending channels having walls of appreciable height against which said portion surfaces are engaged.

Claims

1. A pushbutton switch comprising a body, a pushrod movable into and out from said body, said pushrod having a mounting portion comprising an upper section having a predetermined width and a lower section having a lesser width and defining with said upper section substantially longitudinally extending channels terminating in end walls at those ends of said longitudinal channels directed away from said body, said mounting portion having substantially vertical side channels open at the top and communicating with said longitudinally extending channels respectively at those ends of said longitudinal channels directed toward said body, a stopper plate mounted on and extending from said pushrod and having depending arms with inwardly extending parts, said arms being spaced from one another by a distance no less than said predetermined width, said parts being spaced from one another by a distance less than said predetermined width and no less than said lesser width, said vertical side channels being of a size to accommodate said inwardly extending parts, and a spring active between said body and said stopper plate and effective to urge said stopper plate away from said body, said inwardly extending parts then being urged into engagement with said end walls of said longitudinal channels.

2. The switch of claim 1, in which said stopper plate is essentially rigid.

3. The switch of claim 2, in which the opposing portions of said inwardly extending parts are defined by surfaces of appreciable height, said longitudinally extending channels having walls of appreciable height against which said portion surfaces are engaged.

6. The switch of claim 5, in which said stopper plate is essentially rigid.

7. The switch of claim 6, in which the opposing portions of said inwardly extending parts are defined by surfaces of appreciable height, said longitudinally extending channels having walls of appreciable height against which said portion surfaces are engaged.