US3819891A

US3819891A - Push button switch

Info

Publication number: US3819891A
Application number: US00283645A
Authority: US
Inventors: G Miller; D Bull; N Rautiola
Original assignee: Nartron Corp
Current assignee: Nartron Corp
Priority date: 1972-08-25
Filing date: 1972-08-25
Publication date: 1974-06-25
Anticipated expiration: 1991-06-25

Abstract

A push button type electrical switch assembly has reparable body sections defining therebetween a chamber containing spaced fixed electrical contacts and spaced moveable electrical contacts carried by an arm which is resiliently restrained from moving the moveable contacts toward the fixed electrical contacts when as associated plunger-like actuator is depressed against the arm; after sufficient force is applied to the arm via the actuator the resilient resistance to the movement of the arm is overcome and the moveable contacts are permitted to snap into engagement with the fixed electrical contacts.

Description

United States Patent 1191 Miller et a1.

1 1 PUSH BUTTON SWITCH [75] Inventors: Gerald K. Miller; Dale L. Bull;

Norman A. Rautiola, all of Reed City, Mich.

[73] Assignee: Narton Corporation, Reed City,

Mich.

[22] Filed: Aug. 25, 1972 [21] Appl. No.: 283,645

[52] US. Cl. 200/67 D, 200/159 R, 200/168 G [51] Int. Cl. H01h 13/36 [58] Field of Search 200/67 D, 168 G, 159 R [56] References Cited UNITED STATES PATENTS 1,960,020 5/1934 McGall 200/67 D 2,181,068 11/1939 Riche 200/67 D 2,595,967 5/1952 McCloy 200/67 D 2,714,141 7/1955 Urey et a1. 200/67 D 2,813,943 11/1957 Winter ZOO/67 B 3,153,708 [0/1964 Guthrie 200/83 P June 25, 1974 3,183,333 5/1965 Golbeck 200/159 R 3,209,091 9/1965 Freathy et a1 1 200/51 R 3,588,423 6/1971 Hallerberg ZOO/168 G 3,612,793 10/1971 Roeser ZOO/168 G Primary Examiner-David Smith, Jr. Attorney, Agent, or Firm-Lon H. Romanski 5 7 ABSTRACT 4 Claims, 5 Drawing Figures PUSH BUTTON SWITCH BACKGROUND OF THE INVENTION The prior art has proposed various forms of normally open electrical switch assemblies; however, such have not been found to satisfy a great number of application requirements. For example, especially where relatively high electrical currents are to be experienced in the switch itself, any slow movement of one moveable electrical contact toward another will quickly result in deterioration of such electrical contacts because of electrical arcing which will take place between such contacts as they experience slow relative motion therebetween.

Attempts to, in turn, cause rapid motion of such moveable contacts as by the employment of manually actuated cam means have not proven to be satisfactory because, aside from the increased cost of such earns, the motion of the cam is still, in the main; directly inde pendent upon the rate of speed at which manual actuation is performed.

Other attempts at creating switch assemblies wherein a snap action is introduced into the movement of such moveable contacts have, to a functional degree, succeeded; however, such arrangements have usually required sensitive over-center type tripping mechanisms or other relatively complex and costly mechanisms. Further, in such prior art snap-acting switch assemblies it is usually impossible to attain such a snap-action movement when the total permissible travel of the related actuating member is very short.

Accordingly, the invention as herein disclosed and described is primarily directed to the solution of the above as well as other related problems.

SUMMARY OF THE INVENTION According to the invention, an electric switch assembly comprises at least first and second relatively fixed electrical conductor means spaced from each other, third electrical conductor means normally spaced from said first and second electrical conductor means, resilient restraining means operatively connected to said third electrical conductor means spaced from said first and second electrical conductor means, and actuator means effective for creating a force against said resilient restraining means so as to cause said third electrical conductor means to move toward said first and second electrical conductor means and thereby complete an electrical circuit thereacross.

Various general and specific objects and advantages of the invention will become apparent when reference is made to the following detailed description considered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, wherein for purposes of clarity certain details and elements may be omitted from one or more views:

FIG. I is a perspective view ofa switch assembly embodying the teachings of the invention;

FIG. 2 is an enlarged axial cross-sectional view taken generally on the line 22 of FIG. 1 and looking in the direction of the arrows;

FIG. 3 is a view similar to FIG. 2 but illustrating several of the elements in positions other than that illustrated in FIG. 2;

FIG. 4 is a cross-sectional view taken generally on the plane of line 44 of FIG. 2 and looking in the direction of the arrows; and

FIG. 5 is a fragmentary exploded view of basically two of the elements shown in each of FIGS. 2, 3, and 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now in greater detail to the drawings, FIG. 1 illustrates, in perspective, a switch assembly 10 embodying the teachings of the invention. Generally, as is shown in FIG. 1 and, more specifically in FIGS. 2 and 3, the switch assembly 10 comprises first and second electrically non-conductive body sections or portions 12 and 14 which when assembled, generally define a chamber 16 therebetween. An elastomeric type boot member 18, having a transverse wall 20, may be carried at one end of the body section 14 and secured thereto as by an outer housing 22 which has its one end 24 spun or otherwise formed over an annular portion 26 of boot 18 thereby holding the boot l8 and body or housing sections 12 and 14 in assembled relationship.

A plunger-like actuating member 28 has a first stem portion 30 slideably received within a guide passageway 32 formed in housing or body section 12 and a second stem portion 36 slideably received in a second guide passageway 38 of outer housing or container 22. Intermediate the

stem portions

30 and 36, the actuator 28 is provided with an enlarged cylindrical body 40 which is slideably received within both

cylindrical openings

42 and 44 respectively formed in outer housing 22 and housing section 12 and respectively terminating in radiating annular shoulders 46 and 48. The outer end of stem 36 may be provided with a buttonlike member 50, suitably secured thereto, as for manual engagement thereof.

The shank portion of outer housing 22 is preferably threaded as at 52 for threadable engagement with

cooperating nuts

54, 56 between which a lock-type washer 58 may be situated.

Nuts

54 and 56 may be employed for retaining the entire switch assembly 10 to a suitable related support structure, for example, fragmatairly illustrated at 57.

Body or housing section 12 is preferably provided with a tubular-like extension 60 which is slideably received within a cooperating cylindrical opening 62 in outer housing 22 and which also receives a compression spring 64 for operatively engaging the enlarged portion 40 of actuator 28 and thereby normally resiliantly maintaining the actuator 28 in the position shown with portion 40 abutting against stop shoulder 46. An annular space formed generally between axially spaced portions of outer housing 22 and stem 60 of body section 12, receives a suitable seal therein such as an O- ring 63.

Body or housing section 14, as shown in FIGS. 2, 3 and 4, provides various surfaces many of which are at varying planes or levels with respect to each other. For example, a first surface 66 is provided for securing thereto one end 68 of a switch contact-carrying arm 70 illustrated as being secured by a screw 72 so as to be, as viewed in FIG. 2, normally cantilevered from surface 66.

A second relatively larger surface 74 formed at a Ieval lower than surface 66, when reviewed in FIG. 4, carries a pair of electrically

conductive plates

76 and 78 which at their respective one ends have fixedly retained thereto

electrical contacts

80 and 82 and which at their respective opposite ends are secured to

terminal posts

84 and 86 as by staking the otherwise protruding ends 88 and 90 of

terminals

84 and 86 against or over

conductor plates

76 and 78.

Terminals

84 and 86 are, of course, rigidly secured to the housing or body section 14, in any manner as is well known in the art, thereby permitting the rapid and easy plug-in thereto of any related electrical connector socket (not shown) without causing any movement of any of the elements in the switch assembly which are connected to such terminal posts.

As is best seen in FIG. 4, the contact-carrying arm 70 has a generally medially disposed arm portion 92 and an integrally formed generally laterally extending contact-carrying portion 94 at the moveable end thereof. Also, as best seen in FIG. 4, the arm member 70 has a generally rectangular cut-out 96 formed therein to generally receive therethrough a vertically extending spring-retaining portion or perch 98. A finger-like or tab extension 100 is also carried by the laterial portion 94 in a manner as to be extending generally inwardly of the opening 96.

Finger 100 is adapted to be received within a cooperating aperture 102 formed in one leg 104 of a generally U-shaped spring 106 which has a flange-like portion 108 formed on its other leg 110.

A slot 112 formed in vertical extension or support 98 is adapted to receive therein flange or tab 108 of U- shaped spring 106 as well as a spring retainer 114 of generally L-shaped configuration with the foot portion thereof serving to engage the flange 108 of spring 106 and thereby hold it in the slot 112. With reference to FIG. 2, it can be seen that when the switch assembly is in a normal condition, that is, with plunger actuator 28 in the position shown, leg 104 of spring 106 contained and confined within the opening 96 is resiliently deflected toward the other leg 110 as well as toward the spring perch 98.

As illustrated in FIGS. 2, 3 and 4 in the preferred form, a relatively thicker plate-like electrical conductor 116 is carried atop the lateral portion 94 of arm member 70 and, in turn, is electrically connected to electrical contacts 118 and 120 which have their contacting portions disposed below the lateral portion 94 and so located as to be generally juxtaposed to

fixed contacts

80, 82, respectively.

In addition to the various internal surfaces already described, housing or body section 14 also carries a pedestal-like portion 122 defining a stop or abutment surface 124 which, in the embodiment shown, is at a level or elevation generally between surface 66 and surface 74.

OPERATION OF THE INVENTION As generally indicated in FIG. 1,

terminals

84 and 86 are adapted for connection to associated circuit means such as having terminal 86 placed in circuit with a grounded source of electrical potential 126 while terminal 84, through conductor means 128, is placed in circuit with electrically energizeable means 130 which, for example, may be an electrical starter system for an internal combustion engine.

In the normal condition of the switch assembly, the various elements comprising switch assembly 10 would assume positions as depicted in FIGS. 2 and 4. At this time the resilient force of the somewhat loaded U- shaped spring 106 causes the lever or arm member to assume a position which results in the lowest possible preload to exist in U-shaped spring 106. This, of course, causes arm member 70 to assume a position substantially as depicted in FIG. 2 with the result that upper moveable contacts 118 and 120, carried by lateral transverse portion 94, are held away from lower fixed electrical contacts and 82, respectively. In this condition, the electrical circuit through the switch assembly 10 is open.

When it is desired that the switch assembly complete or close an electrical circuit therethrough, the switch actuator 28 is depressed, against the resilient resistance of spring means 64 so as to thereby, through end 132 of electrically non-conductive plunger actuator 28, apply a force against the arm member generally in the vicinity of 134 of medial arm 92.

When a force is thusly applied, medial arm 92, be cause it is preferably resiliently deflectable, starts to move toward surface 124 of pedestal portion 122 in a somewhat bowed configuration. That is, the initial force applied as at 134 of medial arm 92 is not sufficient to overcome the resilient resistance of U-shaped spring 106 which must experience a degree of increased deflection before it will permit downward movement of the lateral portion 94 and electrical contacts 118 and 120 carried thereby.

Accordingly, as actuator plunger 28 continues to exert an increased downward force against the medial arm 74 causing it to bow to a greater extent, the U- shaped spring 106 experiences two directional resulting force components. One of such components causes leg 104 to be further deflected toward opposed leg while the other force component is generally parallel to the direction of movement of actuator means 28 tending to move or deflect the U-shaped spring 106 generally into the body recess 130. When such force components become sufficiently great, the U-shaped spring 106 in effect snaps to the position generally depicted in FIG. 3 (while still exhibiting a slight upward resilient force) permitting the lateral transverse portion 94 to correspondingly move downwardly and causing moveable contact 118 to engage fixed electrical contact 80 and simultaneously causing moveable contact to engage'fixed contact 82 thereby completing the electrical circuit from terminal 86, plate conductor 78, fixed contact 82, moveable contact 120, conductor plate 1 16 (as well as lateral portion 94 if it is conductive), moveable contact 118, fixed contact 80, plate conductor 76, and terminal 84.

Of course, when the external force applied to the actuator means 28 is removed, both the resilience of arm 70 and any existing resilience of spring 106 cause the arm 70 including the lateral transverse portion 94 thereof to again move upwardly assuming a position as generally depicted in FIG. 2.

Various modifications of the invention are contemplated. For example, in applications where a boot-type seal such as 18 is not necessary such boot 18 may be eliminated. Further, it is conceivable that the separate housing or body section 12 can in effect be eliminated by combining the functional aspects thereof with, for example, the outer housing 22. Obviously, the overall length of the switch assembly may be suitably altered to meet whatever requirements there may exist in terms of its application to related structure.

Other modifications include the possibility of eliminating the

fixed contacts

80, 82 and merely employing the surfaces of

plates

76 and 78 as the electrically contacting surfaces. Further, even though the transverse plate-type conductor 116 has been illustrated as being atop the lateral transverse portion 94, such plate-type conductor 116 may actually be positioned on the underside of lateral portion 94 and, in such case, of course, moveable contact 118 and 120 could also be eliminated thereby permitting the plate conductor 116 to serve as the contacting means. Also, even through the deflectable arm 70 has been illustrated as being formed of electrically conductive material (which may be any suitable metal such as, for example, beryllium copper) it may nevertheless be formed of nonconductive material as, for example, plastic.

Further, the switch assembly has been illustrated employing

male type terminals

84, 86. It should, of course, be apparent that other types of tenninal means could be employed among which, for example, would be female type socket terminals, ring type terminal forming a part of an associated wiring harness.

The invention also contemplates the modification of dispensing with the outer housing 22 and employing, for example, an annular retainer to hold body or housing sections 12 and 14 together. It would, of course, be possible to secure such a modified assembly to the related support structure as by a push-on type fastener, well known in the art, applied to the outer surface of extension 60 of housing section 12.

Although only one preferred embodiment of the invention has been disclosed and described, it is apparent that other embodiments and modifications of the invention are possible within the scope of the appended claims.

We claim:

1. A normally open electric switch assembly, comprising at least first and second relatively fixed electrical conductor means spaced from each other, third electrical conductor means normally spaced from said first and second electrical conductor means, resilient restraining means operatively connected to said third electrical conductor means and normally resiliently maintaining said third electrical conductor means spaced from said first and second electrical conductor means, manually engageable and actuatable electrically non-conductive actuator means effective for creating a force against said resilient restraining means so as to cause said third electrical conductor means to move simultaneously toward said first and second electrical conductor means for operative electrical contact therewith and thereby complete an electrical circuit from said first to said second electrical conductor means, an arm member, said arm member being supported in a manner providing for deflection of at least a portion thereof, said first electrical conductor means comprising a first fixed electrical contact portion, said second electrical conductor means comprising a second fixed electrical contact portion, said third electrical conductor means comprising a separate plate-like conductor secured to said arm portion and of a length effective for completing an electrical current path as between said first and second electrical contact portions, said actuator means being effective for operatively engaging said arm member for causing said third electrical conductor means to move toward an electrically closed position simultaneously against said first and second fixed electrical contact portions, first and second housing sections, said first housing section being effective for carrying said first and second electrical conductor means, said first housing section carrying said resilient restraining means in a manner as to be situated generally medially of said first and second electrical conductor means, said arm member being cantilevered from a portion of said first housing section, said first housing section further comprising an abutment portion formed in general juxtaposition to said arm member, said actuator means comprises a plunger-like member slideably received within said second housing section, said abutment portion being effective for providing a fixed stop for limiting the degree of deflection of said arm member by said plunger member, said abutment portion being so located as to be generally axially medially of said first housing section, said plunger-like member being so located as to be generally axially aligned with the axial medial portion of said second housing section, a pair of terminal members, each of said terminal members extending through and being secured to said first body section, one of said terminal members being connected to said first electrical conductor means and the other of said terminal members being connected to said second electrical conductor means, a first seal secured to said first body section as to cover an axial end face of said first body section and to annularly circumscribe and sealingly engage each of said pair of terminal members, said seal also including an annular portion generally circumscribing said first body section, a second seal operatively sealingly engaging said plunger-like member, and an outer housing effective for engaging said second housing section and said annular portion of said first seal to thereby hold said first and second housing sections in sealed assembled relationship and simultaneously be effective for containing said second seal in sealing engagement with said plunger-like member.

2. An electric switch assembly according to claim 1 wherein said third electrical conductor means also comprises first and second electrical contact members, wherein said separate plate-like conductor is carried by said portion of said arm member in a manner as to be disposed on a first side of said portion of said arm member which is opposite to a second side thereof juxtaposed to said first and second fixed electrical contact portions, said separate plate-like conductor being retained to said portion of said arm member by said first and second electrical contact members, each of said first and second electrical contact members being disposed on said second side of said portions of said arm member and extending through said portion of said arm member to retainingly engage said separate plate-like conductor and thereby contain said portion of said arm member generally between said first and second electrical contact members on one side thereof and said separate plate-like conductor on the other side thereof, and said first and second electrical contact members being spaced from each other as to be in generally respective juxtaposed relationship to said first and second fixed electrical contact portions.

3. An electric switch assembly according to claim 1 wherein said resilient restraining means comprises a U- shaped spring member having a first leg thereof secured directly to a fixed electrically non-conductive portion of said first housing section, wherein said arm member is formed to provide an opening therethrough, wherein a second leg of said U-shaped spring member extends through said opening, wherein said second leg includes an aperture formed therethrough, and wherein said arm member comprises a finger-like extension extending generally inwardly of said opening as to be thereby received within said aperture in said second leg whereby movement of said third electrical conductor means toward said first and second fixed electrical contact portions causes generally corresponding movement of said second leg of saidU-shaped spring member.

4. A normally open electric switch assembly, comprising at least first and second relatively fixed electrical conductor means spaced from each other, third electrical conductor means normally spaced from said first and second electrical conductor means, resilient restraining means operatively connected to said third electrical conductor means and normally resiliently maintaining said third electrical conductor means spaced from said first and second electrical conductor means, manually engageable and actuatable electrically non-conductive actuator means effective for creating a force against said resilient restraining means so as to cause said third electrical conductor means to move simultaneously toward said first and second electrical conductor means for operative electrical contact therewith and thereby complete an electrical circuit from said first to said second electrical conductor means, an arm member, said arm member being supported in a manner providing for deflection of at least a portion thereof, said first electrical conductor means comprising a first fixed electrical contact portion, said second electrical conductor means comprising a second fixed electrical contact portion, said third electrical conductor means comprising a separate plate-like conductor secured to said arm portion and of a length effective for completing an electrical current path as between said first and second electrical contact portions, said actuator means being effective for operatively engaging said arm member for causing said third electrical conductor means to move toward an electrically closed position simultaneously against said first and second fixed electrical contact portions, first and second housing sections, said first housing section being effective for carrying said first and second electrical conductor means, said first housing section carry ing said resilient restraining means in a manner as to be situated generally medially of said first and second electrical conductor means, said arm member being cantilevered from a portion of said first housing section, said first housing section further comprising an abutment portion formed in general juxtaposition to said arm member, said actuator means comprising a plunger-like member slideably received within said second housing section, said abutment portion being effective for providing a fixed stop for limiting the degree of deflection of said arm member by said plunger member, said abutment portion being so located as to be generally axially medially of said first housing section, said plunger-like member being so located as to be generally axially aligned with the axial medial portion of said second housing section, a pair of terminal members, each of said terminal members extending through and being secured to said first body section, one of said terminal members being connected to said first electrical conductor means and the other of said terminal members being connected to said second electrical conductor means, a seal operatively sealingly engaging said plunger-like member, and an outer housing effective for engaging said second housing section and said seal to thereby hold said first and second housing sections in assembled relationship and simultaneously be effective for containing said seal in sealing engagement with said plunger-like member.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3,319 ,891

DATED 1 June 25, 1974 INVENTOR(S) I Miller, G. K. Bull, Dale L. and Rautiola, Norman A.

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1,

lines

20 and 21, immediately after "directly" change "independent" to --dependent--.

Column 5, line 14, after "even" change "through" to -though--.

Claim 1, line 42 thereof, immediately after "actuator means" change "comprises" to ---comprising--.

Signed and sealed this 10th day of June 1975.

(SEAL) Attest:

v C. MARSHALL DANN RUTH C. MASON Commissioner of Patents Attesting Officer and Trademarks UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3,319 ,891

Column 1,

lines

20 and 21, immediately after "directly" change "independent" to --dependent--.

Column 5, line 14, after "even" change "through" to -though--.

Signed and sealed this 10th day of June 1975.

(SEAL) Attest:

v C. MARSHALL DANN RUTH C. MASON Commissioner of Patents Attesting Officer and Trademarks

Claims

3. An electric switch assembly according to claim 1 wherein said resilient restraining means comprises a U-shaped spring member having a first leg thereof secured directly to a fixed electrically non-conductive portion of said first housing section, wherein said arm member is formed to provide an opening therethrough, wherein a second leg of said U-shaped spring member extends through said opening, wherein said second leg includes an aperture formed therethrough, and wherein said arm member comprises a finger-like extension extending generally inwardly of said opening as to be thereby received within said aperture in said second leg whereby movement of said third electrical conductor means toward said first and second fixed electrical contact portions causes generally corresponding movement of said second leg of said U-shaped spring member.

4. A normally open electric switch assembly, comprising at least first and second relatively fixed electrical conductor means spaced from each other, third electrical conductor means normally spaced from said first and second electrical conductor means, resilient restraining means operatively connected to said third electrical conductor means and normally resiliently maintaining said third electrical conductor means spaced from said first and second electrical conductor means, manually engageable and actuatable electrically non-conductive actuator means effective for creating a force against said resilient restraining means so as to cause said third electrical conductor means to move simultaneously toward said first and second electrical conductor means for operative electrical contact therewith and thereby complete an electrical circuit from said first to said second electrical conductor means, an arm member, said arm member being supported in a manner providing for deflection of at least a portion thereof, said first electrical conductor means comprising a first fixed electrical contact portion, said second electrical conductor means comprising a second fixed electrical contact portion, said third electrical conductor means comprising a separate plate-like conductor secured to said arm portion and of a length effective for completing an electrical current path as between said first and second electrical contact portions, said actuator means being effective for operatively engaging said arm member for causing said third electrical conductor means to move toward an electrically closed position simultaneously against said first and second fixed electrical contact portions, first and second housing sections, said first housing section being effective for carrying said first and second electrical conductor means, said first housing section carrying said resilient restraining means in a manner as to be situated generally medially of said first and second elecTrical conductor means, said arm member being cantilevered from a portion of said first housing section, said first housing section further comprising an abutment portion formed in general juxtaposition to said arm member, said actuator means comprising a plunger-like member slideably received within said second housing section, said abutment portion being effective for providing a fixed stop for limiting the degree of deflection of said arm member by said plunger member, said abutment portion being so located as to be generally axially medially of said first housing section, said plunger-like member being so located as to be generally axially aligned with the axial medial portion of said second housing section, a pair of terminal members, each of said terminal members extending through and being secured to said first body section, one of said terminal members being connected to said first electrical conductor means and the other of said terminal members being connected to said second electrical conductor means, a seal operatively sealingly engaging said plunger-like member, and an outer housing effective for engaging said second housing section and said seal to thereby hold said first and second housing sections in assembled relationship and simultaneously be effective for containing said seal in sealing engagement with said plunger-like member.