Rotary potentiometer, especially for use as a rotational position sensor to detect the angular position of a shaft

Claim 1

A rotary potentiometer adapted to receive and sense the rotational position of a shaft, the potentiometer having a first axis of rotation, the shaft having a second axis of rotation, said first and second axis being nominally aligned, said potentiometer and said shaft being subject to relative movement at which these axes exhibit relatively small misalignments, said potentiometer comprising: a casing having a central opening for receiving said shaft, the opening having an axis defining said first axis, the shaft having an axis defining the second axis; a resistor support held in fixed position within the casing, said support having an electrical resistance layer; a spring carrier adapted to be coupled to said shaft and disposed in the casing, said carrier being rotatable about a third axis, which when the shaft is not received in the opening is aligned with the first axis; a slider spring fastened in the casing at the spring carrier and being in sliding contact with said layer; and means disposed in the casing for coupling said carrier to said shaft in a connection at which when said first and second axis of rotation are relatively misaligned, the casing will pivot so that its third axis will intersect the second axis and define a small angle therewith, whereby contact pressure exerted by the spring upon the support remains essentially constant in the presence and absence of said misalignment.