Hearing aid volume control

Abstract

A potentiometer and switch combination suitable for use as a hearing aid volume control. A control cap positioned over the potentiometer body is provided with an integral cam which performs the function of switch actuation. Positive seal is provided by an O-ring formed from a flexible, resilient material. The body of the potentiometer holds the control cap in place by means of heat stakes over a lip on the housing and a post having a chevron at its upper end which mates with a recess in the control cap. The cap is positioned by heat staking to press the stiffly flexible, resilient material of the O-ring into frictional sealing relation with an abutting member and thereby seal the interior of the potentiometer housing. The sealing arrangement also introduces a torque which opposes the rotation of the control cap, thus providing positional stability and positive operating feel. The switch includes conductive strips held by the body, one strip forming a first contact surface and another strip forming a spring detent and a second contact surface. Rotating the cap moves the cam so as to actuate the switch, and also causes the spring detent to snap so as to give the operator a positive switching feel.

Dependencies are inferred from the claim text.