Contact indicator with direction dependent contact pairs - held open by return springs when indicator is at zero position for reliable switching

摘要

A contact indicator device has contact pairs closing dependent on the direction of rotation of the indicator and held open with return springs when the indicator is in the null position. This enables reliable signal reproduction with smallest possible reaction to the indicator displacement torque. The device ensures bounce free contact and reliable separation at the beginning and end of the indicator movement respectively. A friction plate is mounted concentric with the indicator rotation axis and has a two armed linkage with a rotation axis parallel to the indicator axis and eccentric to it. One arm is in contact with a stud on the indicator. The other arm rests against the plate via the return spring. Each contact pair has a part fixed to the plate and one fixed to the indicator.