Torque limiting coil or spring clutch mechanisms

Claim 1

A NORMALLY DISENGAGED HELICAL COIL CLUTCH MECHANISM OPERABLE AS A STARTER UNIT, COMPRISING AN INPUT CLUTCH DRUM MEMBER FOR CONNECTION TO A STARTING PRIME MOVER, AN OUTPUT CLUTCH DRUM MEMBER AXIALLY ADJACENT THERETO AND COAXIAL THEREWITH FOR CONNECTION TO AN ENGINE OR SIMILAR LOAD TO BE STARTED, A MAIN HELICAL COIL SPRING CONNECTED AT ONE END TO TURN WITH THE INPUT DRUM MEMBER AND HAVING COILS DISPOSED INTERMEDIATELY OF ITS OPPOSITE ENDS AROUND BUT NORMALLY IN RADIALLY SPACED RELATIONSHIP TO A CLUTCH DRUM SURFACE OF THE OUTPUT DRUM MEMBER AND HAVING ONE OR MORE FREE END COILS EXTENDING AXIALLY BEYOND SUCH DRUM SURFACE IN A DIRECTION AWAY FROM THE INPUT DRUM MEMBER, A CONTROL COLLAR JOURNALLED TO TURN FREELY INDEPENDENTLY OF BOTH DRUM MEMBERS ABOUT SAID AXIS, THE CONTROL COLLAR HAVING A CIRCULAR DRUM SURFACE AGAINST WHICH SAID FREE END COIL OR COILS ARE PRELOADED RADIALLY TO DRIVE THE COLLAR WHILE PERMITTING OVERRUN OF SAID COIL OR COILS THEREON WHEN TORQUE IS APPLIED TO THE SPRING IN THE STARTING DIRECTION, AND CENTRIFUGAL CLUTCH MEANS BETWEEN THE CONTROL COLLAR AND THE OUTPUT DRUM MEMBER ARRANGED FOR OPERATION AT A CRITICAL PREDETERMINED SPEED OF THE INPUT DRUM MEMBER AND THE CONTROL COLLAR TO CAUSE THE CONTROL COLLAR TO LAG ANGULARLY BEHIND THE ROTATING INPUT DRUM MEMBER AND, VIA OVERRUNNING FRICTION OF THE PRELOADED FREE END COIL OR COILS OF THE MAIN CLUTCH SPRING ON THE CONTROL COLLAR, MOVE SAID INTERMEDIATELY DISPOSED COILS OF THE MAIN SPRING INTO GRIPPING CONTACT WITH THE CLUTCH DRUM SURFACE OF THE OUTPUT DRUM MEMBER.