Pedal crank mechanism for exerciser

Claim 1

A PEDAL CRANK OF THE TYPE FOR DRIVING THE FEET OR LEGS OF A PERSON ON A MOTOR-DRIVEN EXERCISING MACHINE, SAID CRANK HAVING A PLURALITY OF ALTERNATIVE SETTINGS OF LENGTH OF PEDAL STROKE, SAID PEDAL CRANK COMPRISING A MAIN PEDAL CRANK MEMBER AND A SHORTER EXTENSION LINK MEMBER, EACH HAVING AN END RING, SAID RINGS BEING IN FACE TO FACE ENGAGEMENT WITH EACH OTHER AND HAVING RESPECTIVELY A NUMBER OF INTERLOCKING TEETH AND DEPRESSIONS IN REGISTERING RELATION AT SAID CONTACTING FACES, AND A SCREW CLAMPING SAID RING TOGETHER, SAID SCREW HAVING A HEAD, A SEAT FOR SAID HEAD, NEAR THE OUTER FACE OF ONE OF SAID RINGS, AT LEAST THE OTHER OF SAID RINGS BEING TAPPED FOR ACCOMODATING THE CORRESPONDING THREADED LENGTH OF THE SCREW, ONE OF SAID JUXTAPOSED RING FACES HAVING FOUR EQUIDISTANT TEETH PROTRUDING LATERALLY THEREFROM AND THE OTHER HAVING FOUR CORRESPONDING DEPRESSIONS FOR ACCOMMODATION OF SAID TEETH, TO PERMIT ASSEMBLY OF THE LINK TO THE MAIN CRANK PEDAL MEMBER IN ANY OF FOUR POSITIONS, VIZ, (A) AS AN EXTENSION TO THE MAIN PEDAL CRANK MEMBER, (B) FOR PLACEMENT IN OPPOSITION TO THE DIRECTION OF EXTENSION, (C) IN POSITION EXTENDING LATERALLY OF THE LENGTH OF SAID MAIN CRANK PEDAL MEMBER TO THE RIGHT OR (D) IN POSITION EXTENDING LATERALLY OF THE LENGTH OF SAID MAIN CRANK MEMBER TO THE LEFT.