Patent ID: 7793553

Claim:
A specimen grip assembly for use in a materials testing machine comprising: first and second specimen grips for securely holding an end portion of a test specimen therebetween, the first and second grips respectively having first and second outwardly located surfaces, each of the first and second surfaces being inclined at a first predefined angle; and a grip shell having first and second internal inclined surfaces, each of the first and second internal inclined surfaces of the grip shell being inclined at a predefined angle complementary to the first predefined angle at which the first and second surfaces, respectively, of the specimen grips are inclined, the grip shell being positioned around the specimen grips such that the first and second surfaces of the specimen grips abuttingly mate with and slide against the first and second inclined surfaces, respectively, of the grip shell so as to define a wedge-like interface between each specimen grip and the grip shell; wherein, once the specimen grip assembly is fixedly secured within a jaw of the testing machine, a subsequent tensile or compressive force applied through the jaw and the grip assembly and sufficient to deform the test specimen will not generate any appreciable and noticeable compliance in the first and second specimen grips.