Material hardness testing apparatus
OwnerPaul Gilbertoinventor
Life of this patent
Estimating the term…
Abstract
The surface hardness of material is tested by the extent of penetration of a tool thereinto by moving the tool onto the surface from a low to a high value of compressive force and then back to the low value by reversible rotative movements with the penetration being determined from the difference between the two rotative movements, in which the movement may be related to incremental rotative steps with the difference in the number of steps determining the extent of penetration and in which the movement may be automatically performed. The improvements comprise differential thread means comprising a rotatable part and means for revolving the rotatable part to effect linear movement of the penetrating end, and flexure means allowing free axial motion but preventing rotation of the rod (21) therebetween.
Claims19
In an apparatus for testing the hardness of material comprising a rigid platform on which the material is adapted to be positioned, a frame spaced from the platform, means mounted on the frame for linear movement towards and away from the platform, said means comprising an end part (21) adjacent the platform and having a penetrating end (28) adapted to engage the surface of the material (14) and an other end (20) adjacent the frame 16, compressive force measuring means (26, 29) for indicating the force exerted by the penetrating end on the material, and penetrating motion measuring means (31, 32) for indicating the penetrating motion of the penetrating end into the material, the improvement comprising:
- differential thread means comprising a rotatable part (18) having a pair of coaxial threads (19, 19) of different pitches formed thereon;
- means (17) on the frame (16) engaging the threads of one pitch;
- means on the other end (20) of the end part (21) engaging the threads of another pitch;
- means (30) for revolving the rotatable part to effect linear movement of the penetrating end, and flexure means (23) connected between the frame 15 and the end part allowing free axial motion between said frame and said end part but preventing relative rotation therebetween.
Dependencies are inferred from the claim text.