Workpiece clamp and tool shielding device and combination thereof with a tool applying apparatus

摘要

A housing is detachably connected to one arm of the C-frame of a hardness tester. The arm carries a reciprocable plunger on one end of which is a penetrator. The other arm carries an adjustable anvil. The penetrator is forced by the plunger against a workpiece disposed on an anvil for testing hardness. The housing wall is in surrounding spaced relation to the plunger. The housing carries a workpiece clamping and tool shielding sleeve which is coaxial with the plunger and penetrator and which projects through the end of the housing adjacent the anvil so that the outer end of the sleeve can engage the workpiece over a substantial area in surrounding spaced relation to the point of application of the penetrator. The sleeve has at its inner end a wide outer radial flange which extends close to the side wall of the housing. An annular abutment plate is secured in the housing in coaxial relation with the flange by a snap ring. A compression coil biasing spring is interposed between the flange and the abutment plate and biases the sleeve to an extended position in which its outer end extends axially beyond the penetrator so that it can effect initial engagement with the workpiece when the sleeve is in its extended position and the plunger concurrently is in its retracted position. In this position the sleeve also surrounds and shields the penetrator. The spring applies sufficient biasing force to clamp the workpiece in fixed position on the anvil preparatory to and during penetration of the workpiece by the penetrator.