Patent ID: 7739919

Claim:
A test specimen holder, comprising: a cylinder body having a chamber, the cylinder body having first and second inclined surfaces facing each other; a first group of wedges and a second group of wedges, each group of wedges having a pair of wedges wherein each wedge has an inclined surface, wherein the inclined surfaces of the first group of wedges engages the first inclined surface of the cylinder body, and wherein the inclined surfaces of the second group of wedges engages the second inclined surface of the cylinder body; and a piston supporting the groups of wedges, the piston being disposed in the chamber, the cylinder body being operable with the piston and the wedges to urge the groups of wedges together with relative movement of the cylinder body with respect to the piston when the chamber is pressurized, wherein each of the wedges moves with respect to the piston and the cylinder body so as to engage a test specimen during relative movement of the cylinder body with respect to the piston when the chamber is pressurized, and wherein the first group of wedges move together and the second group of wedges move together.