Material testing machine for test piece jaws

摘要

PROBLEM TO BE SOLVED: To provide a testpiece grasping device for a material testing machine capable of grasping a testpiece by the optimum grasping force.;SOLUTION: The testpiece grasping device is equipped with an outer frame 203 falling by the energizing force of a compression spring and a grasping tooth 204 subjected to closing driving by the outer frame 203. The inclined surface 203a of the outer frame 203 and the inclined surface 204a of the grasping tooth 204 are brought into a taper contact state and a taper surface is formed into a shape so as to become narrow toward the pulling direction (upward in the figure) by the grasping tooth 204. The grasping tooth 204 is closed when the outer frame 203 falls but the grasping force of the grasping tooth 204 becomes constant because the energizing force of the outer frame 203 is constant. Further, a wedge effect is not brought about during a tensile test because the inclination direction of the taper surface is reverse to a conventional one and the grasping force caused by tensile force is not produced.;COPYRIGHT: (C)2005,JPO&NCIPI