US3659066A

US3659066A - Push-button electrical switches

Info

Publication number: US3659066A
Application number: US54193A
Authority: US
Inventors: William N Schink; Harry J Krol
Original assignee: Indak Manufacturing Corp
Current assignee: Indak Manufacturing Corp
Priority date: 1970-07-13
Filing date: 1970-07-13
Publication date: 1972-04-25
Anticipated expiration: 1989-04-25

Abstract

Each of the illustrated switches comprises a carriage in the form of a flat bar which is slidable through guide slots in a conductive body or bracket. A coil spring is mounted around the carriage and is connected between the carriage and the body. The contactor is secured to one side of the carriage and is engageable with the body. In one embodiment, the carriage is made of insulating material. In the second embodiment, an insulator is provided between the contactor and the carriage, which is made of metal. In both cases, the carriage can be made by an inexpensive stamping operation. The contactor is preferably in the form of a flat blade having a nose portion adapted to be moved into a slot in the body. The nose portion preferably has a pair of tapering edges which are engageable with the body at opposite sides of the slot. The wiping action between the tapering edges and the body insures that good electrical contact will be maintained between the contactor and the body. The contactor preferably has a terminal to which a flexible lead may be attached.

Description

United States Patent Schink et al. [451 Apr. 25, 1972 [5 PUSH-BUTTON ELECTRICAL Primary Examiner-J. V. Truhe SWITCHES Assistant Examiner-Gale R. Peterson 721 Inventors: William N. Schink, Crystal Lake; Harry J. Ammey aurme'ste" Palmauem Hamby Krol, Arlington Heights, both of ill.

[57] ABSTRACT Each of the illustrated switches comprises a carriage in the form of a flat bar which is slidable through guide slots in a conductive body or bracket. A coil spring is mounted around the carriage and is connected between the carriage and the body. The contactor is secured to one side of the carriage and is engageable with the body. in one embodiment, the carriage is made of insulating material. In the second embodiment, an insulator is provided between the contactor and the carriage, which is made of metal. In both cases, the carriage can be made by an inexpensive stamping operation. The contactor is preferably in the form of a flat blade having a nose portion adapted to be moved into a slot in the body. The nose portion preferably has a pair of tapering edges which are engageable with the body at opposite sides of the slot. The wiping action between the tapering edges and the body insures that good electrical contact will be maintained between the contactor and the body. The contactor preferably has a terminal to which a flexible lead may be attached.

6 Claims, 15 Drawing Figures PUSH-BUTTON ELECTRICAL SWITCHES This invention relates to electrical switches and is particularly applicable to automotive-type switches, for use on automobiles, trucks and other vehicles.

One object of the present invention is to provide a new and improved push-button switch which is extremely reliable and serviceable, yet is unusually inexpensive.

A further object is to provide a new and improved push-button switch in which the body, carriage and contactor can all be formed by inexpensive stamping operations.

A further object is to provide a new and improved push-button switch having a contactor in the form of a flat blade arranged to provide a wiping contact action with the body.

Generally, the present invention takes the form of a switch having a body with at least one guide opening therein. A carriage in the form of a flat bar is slidable in said opening. A contactor is secured to one side of the carriage and is engageable with the body adjacent the opening therein. A spring is provided to bias the carriage in one direction.

Preferably, the carriage is in the form of a flat blade having at least one tapering edge portion adapted to engage the body with a wiping action. It is preferred to provide a pair of oppositely tapering edges on the contactor, engageable with the body at opposite edges of the opening. The tapering edges are preferably formed on a nose portion of the contactor, such nose portion being movable into a portion of the opening.-

Preferably, the contactor includes a terminal adapted to receive a flexible lead. The opening in the body preferably comprises a larger portion for guiding the carriage and a smaller portion for receiving the nose portion of the contactor.

In one embodiment, the carriage is made of insulating material. In the second embodiment, an insulator is provided between the contactor and the carriage, which is made of metal. In both cases, the carriage can be made by an inexpensive stamping operation.

Further objects, advantages and features of the present invention will appear from the following description, taken with the accompanying drawings, in which:

FIG. 1 is an elevational view of a switch to be described as an illustrative embodiment of the present invention, the switch being shown in its closed position.

FIG. 2 is a view similar to FIG. 1, but showing the switch in its open position.

FIG. 3 is an elevational view showing the opposite side of the switch. 7

FIG. 4 is a plan view, taken as indicated by the line 4-4 in FIG. 3.

FIG. 5 is a view similar to FIG. 4, but showing the switch in its open position.

FIG. 6 is a fragmentary enlarged elevation, taken generally as indicated by the line 6-6 in FIG. 3.

FIG. 7 is a sectional view, taken along the line 77 in FIG. 2.

FIG. 8 is a fragmentary enlarged longitudinal section, taken generally along the line 8-8 in FIG. 4.

FIG. 9 is an elevational view, similar to FIG. 2 but showing a modified switch constituting another illustrative embodiment of the invention.

FIG. 10 is an elevational view showing the opposite side of the switch of FIG. 9.

FIG. 11 is a plan view, taken generally as indicated by the line l1ll in FIG. 10.

FIG. 12 is a fragmentary enlarged section, taken generally along the line I2-12 in FIG. 9.

FIG. 13 is a fragmentary enlarged section, taken generally along the line l313 in FIG. 9.

FIG. 14 is a view similar to a portion of FIG. 3, but showing a modified construction.

FIG. 15 is a section along the line l5l5 in FIG. 14.

It will be seen that FIGS. 1-8 illustrate a push-button switch which is especially well adapted for automotive service. Thus, for example, the switch 20 can be used as a warning light switch operable by a parking brake lever in such a manner that the light will be energized when the brake is set, so as to warn the driver to release the brake before the car is driven. The switch can also be used as a door operated switch to energize the dome light, or any other desired lights, when the door is opened. The illustrated switch 20 is of the normally closed type, but the invention is also applicable to push-button switches of the normally open type.

The switch 20 comprises a body of bracket 22 which supports a movable carriage 24. It will be seen that the carriage 24 is in the form of a flat bar. Thus, the carriage 24 can easily be made by an inexpensive stamping operation. In this case, the carriage 24 is made of an insulating material, such as a suitable resinous plastic material. However, the carriage 24 can also be made of metal, as will be disclosed in greater detail in connection with the second embodiment of FIGS. 9-13.

At least one guide slot or opening is formed in the body 22 to receive the carriage 24. In this case, the body 22 is formed with two

arms

26 and 28 having aligned slots 30 and 32. The carriage 24 is slidably received in the slots 30 and 32. The illustrated body 22 is made of sheet metal and can easily be formed by an inexpensive stamping operation.

The carriage 24 is biased in one direction by a spring 34 connected between the carriage 24 and the body 22. As illustrated, the spring 34 .is in the form of a compression coil spring, mounted around the carriage 24 and connected between the arm 28 and a shoulder 36 on the carriage. The shoulder 36 is formed by an enlarged end portion 38 of the carriage 24, serving as the operating push-button on the switch. The enlarged portion 38 is slidably received in the slot 30 formed in the arm 26.

A contactor 40 is mounted on the carriage 24 and is engageable with the body 22. At least the portion of the body 22 which is engageable by the contactor 40 is conductive to form contact means. In this case, the entire body 22 is made of sheet metal and hence is conductive. Normally, the body or bracket 22 is secured to some portion of the metal body or frame of an automobile, and hence is electrically grounded to the frame. In virtually all automobiles, one side of the electrical system is grounded to the frame. Thus, the switch 20 is particularly well adapted to perform a switching operation in the ground side of a lamp circuit or the like.

The illustrated contactor 40 is in the form of a flat plate or blade, secured to one side of the carriage 24 which insulates the contactor from the body 22 when the switch is in its open position, as shown in FIG. 2. The contactor 40 can be made very easily from sheet metal by an inexpensive stamping operation.

Various means may be employed to secure the contactor 40 to the carriage 24. As shown, the contactor 40 has four tabs or flanges 42 which are wrapped around the rear end portion of the bar-shaped carriage 24. The contactor 40 also has a locating lug 44 which extends through an opening 46 in the carriage 24. The lug 44 is preferably struck from the contactor 40 and bent at right angles thereto.

The contactor 40 is preferably formed with a flat terminal or lug 48 to which a flexible lead or wire 50 can be connected. A clip 52 is normally connected to the end of the lead 50 and is adapted to be mounted on the terminal 48. The lead 50 has sufficient length and flexibility to provide for the longitudinal sliding movement of the carriage 24.

The contactor 40 preferably has a nose portion 54 which is movable into a portion of one of the slots in the body 22. In this way, one or more edges of the nose portion 54 are engageable with the body 22 at the edges of the slot. As shown in FIG. 7, the slot 32 is formed with side portions 56 of reduced width to receive the nose portion 54. Thus, the carriage 24 is slidable in the larger or main portion of the slot 32, which the nose portion 54 is movable into one of the reduced portions 56. Two reduced portions 56 are provided so that the carriage 24 can be mounted in either of the two possible positions in the slot 32.

The nose portion 54 of the contactor 40 is preferably formed with at least one tapering edge, adapted to engage the body 22 with a wiping action. As shown, the nose portion 54 has a pair of oppositely tapering edges 58 which provide a balanced construction so that the nose portion 54 is self-centering in the reduced slot portion 56. It will be seen that the tapering edges 58 engage the body 22 at opposite edges of the slot portion 56. The nose portion 54, with its tapering edges 58, resembles a truncated arrowhead.

Due to the arrangement of the return spring 34, the pushbutton switch is normally closed, in that the tapering edges 58 of the contactor 40 engage the metal arm 28 of the body 22 at opposite edges of the slot portion 56. When the carriage 24 is pushed to the right, as shown in FIG. 2, the contactor 40 is moved out of the engagement with the body 22 so that the switch is opened. The carriage 24, being made of insulating material, insulates the contactor 40 from the body 22.

When the pressure is released from the push-button portion 38 of the carriage 24, the nose portion 54 enters the slot portion 56. The tapering edges 58 engage the arm 28 of the body 22 with a wiping action. The tapering edges 58 cause the nose portion 54 to center itself in the slot portion 56. Due to the wiping action, the contacting surfaces of the contactor 40 and the arm 28 are kept clean so that good electrical contact is maintained. Accordingly, the switch is extremely reliable and long-lived. The contactor 40 is normally made of brass or the like, but the body 22 can be made of ordinary sheet steel with zinc or cadmium plating. The carriage 24 can be stamped from a phenolic sheet-material. Thus, all of the components of the switch are extremely low in cost.

FIGS. 9-13 illustrate a modified switch 60 which utilizes essentially the same body 22 as already described. However, the switch 60 has a carriage 64 which is stamped from sheet steel or some other sheet metal. The spring 34 is also the same as before. It will be seen that the spring 34 is compressed between the arm 28 and a shoulder 66 on the carriage 64. As before, the shoulder 66 is formed by an enlarged end portion 68 on the carriage 64. The guide slots and 32 in the

arms

26 and 28 are the same as before, except that the slot 32 has only one reduced side portion 56.

The switch 60 comprises a contactor 70 which is very much the same as before, except that an insulator 72 is interposed between the contactor 70 and the carriage 64. In the illustrated construction, the insulator 72 is secured to the carriage 64, while the contactor 70 is secured to the insulator 72. Various means may be employed to make these connections. As shown, the carriage 64 is formed with a lug 74 which is struck from the carriage and bent at right angles thereto. The lug 74 extends through a slot 76 in the insulator 72. The end of the lug 74 is preferably staked to retain the insulator 72 thereon.

The illustrated contactor 70 is formed with two tabs 78 which extend through a pair of slots 80 in the insulator 72. The ends of the tabs 78 are preferably staked to anchor them on the insulator 72.

Except as otherwise described above, the switch 60 of FIGS. 9-13 is the same as the switch 20 of FIGS. 1-8. Similar components of the two switches have been given the same reference character, to avoid any need for repeating the details of the description.

FIGS. 14 and 15 illustrate a modified construction, similar to that of FIGS. 1-8, except that the lug 44 is replaced by a tubular extrusion or eyelet 144, formed from the metal of the contactor 40. The extrusion 144 extends through a circular locating hole 146 in the insulating carriage 24.

It will be evident that the switches of the present invention are especially well adapted for use on automobiles as brake switches or door switches. When one of the switches is used as a parking brake switch, it is held open by the brake lever, or some other control member, when the brake is released. When the lever is moved to its actuated position, the switch is allowed to close by its own spring action, so as to energize a warning light or the like. In the usual arrangement, the warning light is caused to flash, when energized, so as to warn the driver to release the brake before trying to drive the car. The

switch can also be arranged to operate by a brake pedal, so as to energize the stop lights when the pedal is depressed.

When the switch is used as a door switch, the dome light or any other lights in the automobile are energized when the corresponding door is opened. When the door is closed, it engages the carriage and moves the contactor out of engagement with the grounded body.

The illustrated switches are normally closed when the pushbutton is not actuated. However, the invention is also applicable to normally open push-button switches.

Various other modifications, alternative constructions and equivalents may be employed, as will be evident to those skilled in the art.

We claim:

1. An electrical switch,

comprising a body having a guide slot therein,

a flat bar-shaped carriage of rectangular cross-section slidable longitudinally in said slot,

a spring biasing said carriage in one direction,

said body having stationary conductive contact means with an opening therein adjacent said carriage,

and a thin flat contactor secured to one side of said carriage in parallel relation thereto and movable therewith,

said contactor having a thin flat blade-like nose portion of tapered width movable edgewise into said opening and having a pair of oppositely slanting edges engageable with said contact means at opposite sides of said opening, the opposite slant of said edges causing said nose portion to center itself in said opening to produce firm contact pressure between both slanting edges and said contact means,

the thin fiat construction of said nose portion and the edgewise engagement between said slating edge and said contact means producing enhanced contact pressure therebetween.

2. A switch according to claim 1,

in which said carriage is made of insulating material to insulate said contactor fromsaid contact means except when said contactor engages said contact means.

3. A switch according to claim 1,

including an insulator mounted between saidv carriage and said contactor,

said carriage being made of conductive material.

4. A switch according to claim 1,

including a thin plate-like insulator mounted between said carriage and said contactor,

said carriage being made of conductive material.

5. A switch according to claim 1,

in which said opening merges into one side of said guide slot in said body,

said opening having a width which is less than that of said guide slot.

6. An electrical switch,

comprising a body having a guide slot therein,

an elongated carriage slidable longitudinally in said slot,

a spring biasing said carriage in one direction,

and a thin flat contactor secured to said carriage and movable therewith,

said contactor having a thin flat blade-like nose portion of tapered width movable edgewise into said opening and having a pair of oppositely slanting edges engageable with said contact means at opposite sides of said opening,

the opposite slant of said edges causing said nose portion to center itself in said opening to produce firm contact pressure between both slanting edges and said contact means, the thin flat construction of said nose portion and the edgewise engagement between said slanting edges and said contact means producing enhanced contact pressure therebetween.

* i 1F t

Claims

1. An electrical switch, comprising a body having a guide slot therein, a flat bar-shaped carriage of rectangular cross-section slidable longitudinally in said slot, a spring biasing said carriage in one direction, said body having stationary conductive contact means with an opening therein adjacent said carriage, and a thin flat contactor secured to one side of said carriage in parallel relation thereto and movable therewith, said contactor having a thin flat blade-like nose portion of tapered width movable edgewise into said opening and having a pair of oppositely slanting edges engageable with said contact means at opposite sides of said opening, the opposite slant of said edges causing said nose portion to center itself in said opening to produce firm contact pressure between both slanting edges and said contact means, the thin flat construction of said nose portion and the edgewise engagement between said slating edge and said contact means producing enhanced contact pressure therebetween.

2. A switch according to claim 1, in which said carriage is made of insulating material to insulate said contactor from said contact means except when said contactor engages said contact means.

3. A switch according to claim 1, including an insulator mounted between said carriage and said contactor, said carriage being made of conductive material.

4. A switch according to claim 1, including a thin plate-like insulator mounted between said carriage and said contactor, said carriage being made of conductive material.

5. A switch according to claim 1, in which said opening merges into one side of said guide slot in said body, said opening having a width which is less than that of said guide slot.

6. An electrical switch, comprising a body having a guide slot therein, an elongated carriage slidable longitudinally in said slot, a spring biasing said carriage in one direction, said body having stationary conductive contact means with an opening therein adjacent said carriage, and a thin flat contactor secured to said carriage and movable therewith, said contactor having a thin flat blade-like nose portion of tapered width movable edgewise into said opening and having a pair of oppositely slanting edges engageable with said contact means at opposite sides of said opening, the opposite slant of said edges causing said nose portion to center itself in said opening to produce firm contact pressure between both slanting edges and said contact means, the thin flat construction of said nose portion and the edgewise engagement between said slanting edges and said contact means producing enhanced contact pressure therebetween.