Flexure assembly for vibration test apparatus

Claim 1

ELECTRODYNAMIC TEST APPARATUS COMPRISING A STATIONARY CORE STRUCTURE, AN ARMATURE MOVABLE WITH RESPECT TO THE CORE STRUCTURE, AND A FLEXURE ASSEMBLY INCLUDING THREE OR MORE FLEXURES INTERPOSED BETWEEN THE ARMATURE AND THE CORE STRUCTURE TO PERMIT FREEDOM OF MOVEMENT OF THE ARMATURE IN AN AXIAL DIRECTION WITH RESPECT TO THE CORE STRUCTURE, THE FLEXURES BEING SPACED CIRCUMFERENTIALLY ABOUT THE ARMATURE TO RESTRAIN THE ARMATURE RADIALLY OF ITS AXIS, EACH FLEXURE INCLUDING AN ARCUATE STRAP OF RESILIENT MATERIAL HAVING A SINGLE 180* PREFORMED BEND IN THE UNSTRESSED CONDITION SO THAT ITS ENDS ARE DIAMETRICALLY DISPOSED IN SPACED PARALLEL RELATIONSHIP TO EACH OTHER AND TO THE AXIS OF THE ARMATURE, THE WIDTH OF THE STRAP BEING SEVERAL TIMES GREATER THAN ITS RADIUS OF CURVATURE TO PROVIDE LATERAL STIFFNESS, AND ATTACHING MEANS FOR RIGIDLY FASTENING THE INNERMOST ENDS OF THE STRAPS TO THE ARMATURE, THE OTHER STRAP ENDS BEING FIXED TO THE CORE STRUCTURE, THE INNERMOST END OF EACH STRAP MOVING TANGENTIALLY TO ITS RADIUS OF CURVATURE WITH A DEFLECTION WHICH IS DIRECTLY PROPORTIONAL TO THE AXIAL FORCE APPLIED TO THE ARMATURE.