Apparatus for fatigue testing under random loads

Claim 1

TENSION APPARATUS FOR FATIGUE TESTING A PREDETERMINED SPECIMEN UNDER SELECTABLE LOADING, AND COMPRISING IN COMBINATION: A RIGID BASE FRAME; MEANS FOR RIGIDLY CLAMPING ONE END OF SAID SPECIMEN RELATIVE TO SAID BASE; A MOVEABLE CLAMP STRUCTURE ADAPTED TO CLAMP THE OTHER END OF SAID SPECIMEN; MEANS SUPPORTING SAID MOVEABLE CLAMP STRUCTURE ON SAID BASE FOR MOTION THEREOF IN THE DIRECTION OF THE LONGITUDINAL AXIS OF SAID SPECIMEN; A LOADING MEMBER EXTENDING FROM SAID MOVEABLE CLAMP STRUCTURE IN A DIRECTION OPPOSITE TO THE SPECIMEN CLAMPED THEREBY AND SUBSTANTIALLY IN ALIGNMENT WITH THE AXIS OF SAID SPECIMEN; A LOADING LEVER SUBSTANTIALLY PARALLEL TO SAID AXIS AND CONNECTED TO SAID LOADING MEMBER IN SUBSTANTIAL ALIGNMENT THEREWITH; MEANS HINGING ONE END OF SAID LEVER TO SAID FRAME AT A POINT SPACED FROM SAID AXIS BETWEEN SAID LEVER AND SAID MOVEABLE CLAMP STRUCTURE; MEANS FOR GENERATING A PREDETERMINED ELECTRICALLY APPLYING A RESPONDING TO SAID SIGNAL FOR MECHANICALLY APPLYING A LOAD TO THE OTHER END OF SAID LEVER AT SUBSTANTIALLY RIGHT ANGELES TO SAID AXIS IN A PLANE CONTAINING SAID AXIS AND HINGE, SAID LOAD VARYING IN AMPLITUDE AND FREQUENCY WITH THE RESPECTIVE AMPLITUDE AND FREQUENCY OF SAID SIGNAL; AND ADJUSTABLE SPRING MEANS EXTENDING BETWEEN SAID LEVER AND SAID BASE FOR LOADING SAID LEVER AND SAID SPECIMEN.