Abstract: A coupling between a linear motion drive shaft and a driven member, suitable for use in a linear motion potentiometer in which the driven member comprises a contact spring mounting block. An O-ring formed from a stiffly deformable, spring material is mounted on the drive shaft and held against a transverse wall on the driven member so as to absorb transverse and angular misalignments of the drive shaft and transmit to the driven member longitudinal drive shaft movements. The coupling exhibits low backlash when the motion of the drive shaft is reversed, and accommodates to both angular and transverse deviations of the shaft away from a linear drive orientation.