摘要 |
Disclosed is a blocked lens thickness gauge for measuring the thickness of a semi-finished lens that is blocked for surfacing of the concave side thereof. A lens contacting sensor shaft is supported between two sets of orthogonally mounted ball bearings and a needle shaft, the latter being supported on spring-loaded bearings such that the needle shaft is urged toward the lens contacting sensor shaft by the spring loading. A slipping clutch is also provided to allow the needle shaft to absorb inertia forces resulting from abnormal shocks. |