Tool fitted with jaw travel measurement device and associated method for force-travel measurement with amplified location resolution towards end of closure

摘要

The travel sensor takes the form of a strain gauge (23) and a piezoelectric element (24) located either side of a leaf spring. The spring is linked through a carrier (8) to a tool jaw (4) and rests on a lug (25) attached to the toggle drive (10) which operates the jaws. As the spring leaf flexes when the jaws close this modifies the electric characteristics of the sensor components. The method of mounting ensures that during the initial closing movement of the jaws the resultant electrical signal is relatively small but in the final stages relatively large