US 4,081,782 A · Combined rotary potentiometer and switch

Abstract

A potentiometer and switch combination including a rotatable control cap positioned over a potentiometer body to form a housing. The cap is provided with an annular flange which abuts an annular shoulder on the body, either the flange or the shoulder being formed from stiffly flexible, resilient material. The body holds the cap in place by means of a post having a chevron at its upper end which mates with a recess in the cap. The cap is positioned to deform the stiffly flexible, resilient material into frictional sealing relation with its abutting member and thereby seal the interior of the housing. The sealing arrangement also introduces a torque which opposes rotation of the cap. The switch includes a conductive strip held by the body, one portion of the strip forming a first contact and another portion forming a spring detent. A cantilever spring blade which holds a second contact adjacent to and radially inward from the first contact urges the contacts together, while a nonconductive blocking member projects downwardly from the cap to separate the contacts when the switch is off. Rotating the cap moves the blocking member out from between the contacts, permitting them to close, and also causes the spring detent to snap against the blocking member and give the operator a positive switch feel. The device is particularly suited for use in a hearing aid.

Claims18

Dependent claims

A rotary potentiometer, comprising:

a body portion having an annular shoulder around its periphery,
a resistance element and collector means secured to said body portion,
termination means associated with said resistance element and collector means,
a control cap rotatably positioned over said body portion and forming therewith a housing for said resistance element and collector means, said cap having an annular flange abutting said body portion shoulder,
means securing said cap to said body portion, and
electrically conductive wiper means controlled by rotation of said cap for electrically and mechanically coupling said resistance element to said collector means,
switch means including first and second contact means situate in said control cap,
dowel means for separating said first and second contact means in response to rotation of said control cap,
at least one of said body portion shoulder and cap flange being formed from a stiffly flexible, resilient material, said securing means holding said cap and body portion together with sufficient pressure to deform said stiffly flexible, resilient material and provide a frictional seal between said body shoulder and cap flange, thereby sealing the interior of said housing and introducing a counter torque to rotation of said cap.

6 more elements

In a rotary potentiometer having a housing forming an interior cavity, a resistance element and collector means held in said chamber, a control cap rotatably secured over said chamber, termination means associated with said resistance element and collector means, and means controlled by rotation of said cap for electrically and mechanically coupling said resistance element to said collector means, the improvement comprising a switch means which comprises:

a first switch contact means held in said chamber and spaced from the center thereof, a second switch contact means, terminals associated with each of said switch contact means, cantilever spring means holding said second contact means adjacent to and radially inward from said first contact means, said spring means urging said second contact means towards said first contact means, and a nonconductive blocking member projecting downwardly from said cap between said first and second contact means, said blocking member being moved out from between said two contact means by rotation of said cap to enable closing of said contact means, and thereafter returning to a position separating said contact means by counter-rotation of said cap.

Dependencies are inferred from the claim text.

Combined rotary potentiometer and switch

Life of this patent

Combined rotary potentiometer and switch

Life of this patent

Abstract

Claims18