US3858148A

US3858148A - Rectilinear potentiometer and switch

Info

Publication number: US3858148A
Application number: US00344275A
Authority: US
Inventors: E Hauenstine
Original assignee: PR Mallory and Co Inc
Current assignee: Duracell Inc USA; Emerson Electric Co
Priority date: 1973-03-23
Filing date: 1973-03-23
Publication date: 1974-12-31
Anticipated expiration: 1991-12-31
Also published as: CA996211A

Abstract

An electrically insulating means cooperates with at least one of a collector and resistance strip to provide a substantially continuous sliding surface for an electrical contact means to provide a switch in combination with a variable resistor. A housing of the potentiometer includes a cup-shaped member molded as a single unit from an electrically insulating material to provide structural support for the various elements of the resistor-switch combination.

Description

United States Patent [191 Hauenstine Dec. 31, 1974 1 RECTILINEAR POTENTIOMETER AND SWITCH [75] Inventor: Edgar F. Hauenstine, Frankfort, Ind.

[73] Assignee: P. R. Mallory & Co. Inc.,

Indianapolis, Ind.

[22] Filed: Mar. 23, 1973 [21] Appl. No.: 344,275

[52] U.S. Cl 338/178, 338/153, 338/183 [51] Int. Cl H010 9/08 [58] Field of Search 338/153, 176, 178, 179,

[56] References Cited UNITED STATES PATENTS 1,536,175 5/1925 Yaxley 338/173 X 2,976,507 3/1961 DiGirolamo et a1. 338/183 X 3,381,254 4/1968 Campbell 338/179 3,732,521 5/1973 Hauenstine et al 338/183 X Primary Examiner.1. V. Truhe Assistant E.raminer-David A. Tone Attorney, Agent, or FirmCharles W. Hoffmann; Robert F. Meyer; Donald W. Hanson [5 7 ABSTRACT An electrically insulating means cooperates with at least one of a collector and resistance strip to provide a substantially continuous sliding surface for an electrical contact means to provide a switch in combination with a variable resistor.

A housing of the potentiometer includes a cup-shaped member molded as a single unit from an electrically insulating material to provide structural support for the various elements of the resistor-switch combination.

10 Claims, 2 Drawing Figures '3 III RECTILINEAR POTENTIOMETER AND SWITCH Generally speaking, the present invention relates to a linear potentiometer switch combination which comprises a housing, apertures in opposed ends of said housing, a collector and resistance strip carried in the housing in spaced substantially parallel relationship, a slider extending through said apertures and movable between the collector and resistance strips, electrical contact means carried by the slider engaging the collector and resistance strips, and an electrical insulating means cooperating with at least one of said collector and resistance strips to provide a substantially continuous sliding surface for said electrical contact means, engagement of the electrical contact means with the electrical insulating means providing the switch of the linear potentiometer switch combination.

The housing is comprised of a rectangular shaped cup-shaped member molded of electrically insulative material as a single unit to include slots receiving collector and resistance strips, ribs supporting at least one of the collector and resistance strips along a side thereof, open ended slots at opposed ends of the cupshaped member receiving a slider carrying electrical contact means, a groove in the bottom of the cup shaped member maintaining alignment of the slider as it slides therein, apertures in the bottom of the cup shaped member through which electrical terminals connected to the collector and resistance strips extend, and posts extending from edges of walls of the cup shaped member at its open end, the housing further including a cover having apertures engaging the posts and being adapted to close said cup shaped member and aid in trapping the collector and resistance strips and the slider in place.

Potentiometers are being increasingly used where mechanical movements need to be transformed into electrical signals and, where occasion demands it because of styling, linear actuated potentiometers are preferred. Linear potentiometers also have a smooth rate of change in resistance.

There are also occasions when there is a need for a switching function in combination with a potentiometer. For example, in sewing machines, the operator varies the speed of the machine through a foot pedal which operates a potentiometer. It would be highly advantageous to combine a switching function with the potentiometer so that by operating the foot pedal the operator could not only vary the speed of the machine, but also turn it on or off.

in addition it is always desirable to provide a device that is easy to produce and therefore lower in cost.

A feature of the present inventon is, therefore to provide a linear potentiometer switch combination. Another feature of the invention is to provide a device that is easy to produce. Still another feature of the invention is to provide a linear potentiometer switch combination wherein an electrical insulating means cooperates with at least one of a collector strip and resistance strip to provide a substantially continuous sliding surface for an electrical contact means engaging the two strips. Yet another feature of the invention is to provide a linear potentiometer switch combination wherein an electrical insulating member is disposed juxtaposition a collector strip to provide a substantially continuous sliding surface therewith. Yet still another feature of the invention is to provide a housing for a linear potentiometer which includes a cup-shaped member and a cover closing same, the cup shaped member being molded from an electrically insulating material to include in a single unit structural support for the various elements of the resistor-switch combination. These and other features of the invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein:

FIG. 1 is an exploded view of a potentiometer showing the features of the invention; and

FIG. 2 is a top view of the potentiometer.

Referring now to the drawings there is shown a rectilinear potentiometer switch combination illustrating the features of the invention. In general the combination includes a housing 12 in which there is disposed a resistance strip 14, a collector strip 16, a slider 18 which slides between the two strips, an electrical contact means 20 carried by the slider, and an on-off switch 22.

Housing 12 includes a cup-shaped member 24 having an open end 26 which is closed by a cover 28. The cupshaped member is molded from a suitable electrically insulating material such as a plastic to provide as a single unit structural support for the elements of the potentiometer-switch combination.

Slots

29 and 30 are provided along an inner wall 32 receiving resistance strip 14. Also provided along inner wall 32 are a plurality of ribs 34 which bear against a side of the resistance strip to provide further support for the strip.

Slots

36 and 38 receive collector strip 16 along an opposed inner wall 40 to maintain the strips in spaced, substantially parallel relation.

Apertures

42 and 44, in the form of open ended slots, are provided for carrying slider 18, the slides being free to slide lengthwise between the collector and resistance strips. A groove 46 is formed in the bottom 48 of the cup-shaped member in which slider 18 slides through extension 50. A plurality of posts 52 extend from walls of the cup-shaped member at its open end to which cover 28 is attached through suitable apertures 51, the posts being flattened to hold the cover in place. The cover thus traps slider 18 in

slots

42 and 44 and also traps the collector and resistance strips in their slots. Thus cup-shaped member 24 provides, as a single molded unit, support for the elements of the potentiometer.

Slider 18 is comprised of a thin rectangular bar 18 having an aperture 56 disposed near its center section. The travel of the slide is limited by

lugs

58 and 60 engaging the walls of the housing.

Electrical contact means 20 includes a plurality of fingers 54 carried on a side of slider 18. Some of the fingers engage resistance strip 14, the others engaging collector strip 16 through aperture 56.

Electrical terminals

62 and 64 are electrically connected to resistance strip 14 through clips 62' and 64', the terminals extending through the bottom of the cupshaped member 24 through suitable holes. Clips 62' and 64 have a lip 62" which aids in placing the clips in place with respect to the resistance strip 14. More specifically, strip 14 is positioned in

slots

29 and 30 and then the terminals are placed over the strip with the terminal ends being fed through the holes in the bottom of cup-shaped member 24. The clip ends are then engaged over the strip and allowed to fill the thickness of the slots for good alignment. Terminal 66 is integrally formed with collector strip 16, the terminal also extending through the bottom of cup-shaped member 24 through a suitable hole 63.

Switch 22 includes an electrical insulating means 23 cooperating with collector strip 16 to provide a substantially continuous sliding surface 68 over which electrical contact means 22 may slide. In the illustrative embodiment, electrical insulating means comprises a land 70 formed as part of the inner wall 40 of the cupshaped member.

In operation, movement of slider 18 causes electrical contact means 22 to slide up and down the lengths of resistance and

collector strip

14 and 16, collector strip 16 serving as electrical ground. As the electrical contact means moves along resistance strip 14, the resistance output is varied accordingly. When electrical contact means 22 moves off collector strip 16 onto land 70, the electrical circuit is broken, so that the potentiometer also provides an on-off switching function.

The potentiometer-switch combination may be pivotly mounted through

posts

72 and 74 which may be pivotly mounted in a frame 76.

What is claimed is:

l. A combination linear potentiometer and switch comprising:

a. a housing,

b. apertures in opposed ends of said housing,

c. a collector strip and a resistance strip carried in said housing in spaced substantially parallel relationship,

d. a slider extending through said apertures and movable between said collector and resistance strips and having lugs engaging walls of said housing to limit the travel thereof,

e. electrical contact means carried by said slider engaging said collector and resistance strips, and

f. an electrical insulating means cooperating with at least one of said collector and resistance strips to provide a substantially continuous sliding surface for said electrical contact means, engagement of said electrical contact means with said electrical insulating means providing said switch.

2. The combination according to claim 1 wherein said electrically insulating means comprises a member in juxtaposition with said collector strip at one end thereof.

3. The combination according to claim 2 wherein said member comprises a portion ofa wall of said housmg.

4. The combination according to claim 1 wherein said slider comprises a thin bar, substantially rectangular in cross-section.

5. The combination according to claim 4 wherein there is an aperture in said bar and said electrical contact contact means includes a plurality of fingers carried by said bar, a number of said fingers engaging one of said collector and resistance strip, the other of said fingers extending through said aperture to engage the other of said strips.

6. The combination according to claim 1 wherein said housing includes a cup-shaped member and a cover closing same.

7. The combination according to claim 6 wherein said cup-shaped member includes slots provided in walls thereof trapping said collector and resistance strips, said apertures comprise slots, and said cover further traps said slider in said slots and further traps said collector and resistance strips in said slots.

8. The combination according to claim 1 further including posts extending from said housing for pivotly mounting said housing to a frame.

9. In a rectilinear potentiometer wherein an electrical contact means slideably engages spaced parallel collector and resistance strips, a rectangular shaped housing comprising:

a. a rectangular cup-shaped member molded of electrically insulative material as a single unit to include: slots receiving said collector and resistive strips, ribs supporting at least one of said collector and resistance strips along a side thereof,

open ended slots at opposed ends of said cupshaped member receiving a slider carrying said electrical contact means,

a groove in the bottom of said cup-shaped member maintaining alignment of said slider as it slides between said collector and resistance strips,

apertures in the bottom of said cup-shaped member through which electrical terminals, connected to said collector and resistance strips extend, and

posts extending from edges of walls of said cupshaped member at its open end,

b. a cover having apertures engaging said posts, said cover adapted to close said cup-shaped member and aid in trapping said collector and resistance strips and said slider in place.

10. In a rectilinear potentiometer according to claim 9 wherein said cup shaped member further includes a land in juxtaposition with and cooperating with said collector strip to provide a continuous sliding surface for said electrical contact means whereby a switch is provided in combination with said variable resistor.

Claims

1. A combination linear potentiometer and switch comprising: a. a housing, b. apertures in opposed ends of said housing, c. a collector strip and a resistance strip carried in said housing in spaced substantially parallel relationship, d. a slider extending through said apertures and movable between said collector and resistance strips and having lugs engaging walls of said housing to limit the travel thereof, e. electrical contact means carried by said slider engaging said collector and resistance strips, and f. an electrical insulating means cooperating with at least one of said collector and resistance strips to provide a substantially continuous sliding surface for said electrical contact means, engagement of said electrical contact means with said electrical insulating means providing said switch.

3. The combination according to claim 2 wherein said member comprises a portion of a wall of said housing.

9. In a rectilinear potentiometer wherein an electrical contact means slideably engages spaced parallel collector and resistance strips, a rectangular shaped housing comprising: a. a rectangular cup-shaped member molded of electrically insulative material as a single unit to include: slots receiving said collector and resistive strips, ribs supporting at least one of said collector and resistance strips along a side thereof, open ended slots at opposed ends of said cup-shaped member receiving a slider carrying said electrical contact means, a groove in the bottom of said cup-shaped member maintaining alignment of said slider as it slides between said collector and resistance strips, apertures in the bottom of said cup-shaped member through which electrical terminals, connected to said collector and resistance strips extend, and posts extending from edges of walls of said cup-shaped member at its open end, b. a cover having apertures engaging said posts, said cover adapted to close said cup-shaped member and aid in trapping said collector and resistance strips and said slider in place.

10. In a rectilinear potentiometer according to claim 9 wherein said cup - shaped member further includes a land in juxtaposition with and cooperating with said collector strip to provide a continuous sliding surface for said electrical contact means whereby a switch is provided in combination with said variable resistor.