Parallel motion displacement transducers

摘要

In a parallel motion finger probe, the parallel motion arm is rigidly connected to a shaft which is supported in a linear ball sleeve bearing, instead of by a parallel motion linkage as in prior finger probes. The parallel motion arm can be biassed in either of its two opposite directions of movement by a leaf spring, whose biassing force and direction can be adjusted by a control wheel having an eccentric groove co-operating with a pin on a spring control arm to which the spring is connected. The leaf spring also serves to prevent rotation of the parallel motion arm about the axis of the bearing. Displacement of the parallel motion arm is sensed by an inductive displacement transducer of the LVDT type.