Specimen grip for tensile testing apparatus

Claim 1

A TENSILE TESTING APPARATUS SPECIMEN GRIP FOR ACCEPTING A SPECIMEN FROM THE FRONT, CLAMPING SAID SPECIMEN WITHOUT LONGITUDINALLY STRESSING IT, HOLDING SAID SPECIMEN SELF-TIGHTENINGLY DURING TENSILE TESTING THEREOF, AND RETAINING SAID SPECIMEN DESPITE TESTING TO FAILURE, WHICH COMPRISES: A FRAME WITH A PAIR OF GENERALLY LONGITUDINAL SLIDE PIECES AND A CROSS MEMBER CONNECTING SAID SLIDE PIECES AT CORRESPONDING ENDS THEREOF, SAID SIDE PIECES INCLUDING FACING SURFACES CONVERGING AWAY FROM SAID CROSS MEMBER, SYMMETRICALLY ABOUT A LONGITUDINAL PLANE, TO PROVIDE AN OPPOSED PAIR OF WEDGING SURFACES; A CORE EXTENDING LONGITUDINALLY THROUGH SAID CROSS MEMBER AND TERMINATING IN A MOUNTING END AND A JAWENGAGING END PORTION HAVING A GUIDE SURFACE; A PAIR OF JAWS, EACH JAW HAVING A WEDGING SURFACE, A GUIDE SURFACE, AND A GRIPPING SURFACE; BIASING MECHANISM URGING EACH OF THE JAW WEDGING SURFACES AGAINST ONE OF THE FRAME WEDGING SURFACES AND EACH OF THE JAW GUIDE SURFACES AGAINST THE CORE GUIDE SURFACE, THE GRIPPING SURFACES BEING EQUIDISTANT FROM SAID LONGITUDINAL PLANE ON OPPOSITE SIDES THEREOF AND BEING MOVED TRANSVERSELY RELATIVE TO EACH OTHER RESPONSIVE TO RELATIVE SLIDING MOVEMENT OF SAID JAW WEDGING SURFACES AND THE RESPECTIVE FRAME WEDGING SURFACES, THE MOVEMENT OF SAID GRIPPING SURFACES BEING FREE OF ANY LONGITUDINAL COMPONENT WHILE SAID JAW GUIDE SURFACES ARE AGAINST SAID CORE GUIDE SURFACE, SAID JAWS BEING LONGITUDINALLY MOVABLE AWAY FROM SAID CORE IN SAID TENSILE TESTING, RESPONSIVE TO TENSILE FORCES ON THE SPECIMEN WHICH OVERRIDE SAID BIASING MECHANISM; AND AN ACTUATOR MOUNTED ON SAID CORE INTERMEDIATELY OF THE ENDS THEREOF AND ENGAGING SAID FRAME TO PROVIDE SELECTIVE LONGITUDINAL MOVEMENT THEREOF AND TO HOLD SAID FRAME AGAINST LONGITUDINAL MOVEMENT DURING TENSILE TESTING, SAID FRAME BEING LONGITUDINALLY MOVABLE ON SAID CORE; WHEREBY A SPECIMEN LOADED BETWEEN SAID GRIPPING SURFACES FROM THE FRONT MAY BE CLAMPED BY ACTUATION OF SAID ACTUATOR WITHOUT LONGITUDINALLY STRESSING THE SPECIMEN, AND IS FIRMLY GRIPPED DESPITE THINNING IN TESTING BY ACCOMMODATING LONGITUDINAL MOVEMENT OF THE JAWS AWAY FROM THE CORE, AND WHEREBY SAID CORE AND GUIDE JAW SURFACES COOPERATE TO LIMIT THE TRANSVERSE DISTANCE BETWEEN SAID GRIPPING SURFACES UPON TESTING TO FAILURE TO THE INITIALLY CLAMPED TRANSVERSE DISTNCE, TO RETAIN ANY REMAINING PORTION OF THE SPECIMEN IN THE GRIP.