Raymond R Goulet

US Patent:

49413597, Jul 17, 1990

Filed:

Feb 2, 1989

Appl. No.:

7/306005

Inventors:

George D. Quinn - Watertown MA
Raymond L. Goulet - Norwood MA

Assignee:

The United States of America as represented by the Secretary of the Army - Washington DC

International Classification:

G01N 320

US Classification:

73851

Abstract:

An articulating fixture for the flexure testing of ceramics, having a lower structure for supporting the bottom of a specimen to be tested and an upper structure for placing a load into the top surface of the specimen. Each such structure includes at least one articulated cooperating assembly which allows rotation in the direction of the surface of the specimen whereby when the specimen is twisted, it will adapt to the twist and still properly apply the load to the specimen. In one arrangement, each of the structures includes two lines of pressure provided by two loading pins so that there are four such points in the fixture. In another arrangement, the upper structure includes one line of pressure provided by one loading pin, and the bottom structure includes two lines of pressure provided by two loading pins so that there are three such points in the fixture. The assembly for the lower structure includes a lower support cradle having an arcuate groove extending in the same direction as the specimen, and a swivel bearing support having a convex arcuate surface which mates with the surface of the groove so that the cradle and swivel bearing support are slidable with the swivel bearing support rotating within the groove to accommodate twisted specimens. The loading pin may contact the swivel bearing support on one side and the specimen at another side opposite the first side.