Operating device compreising friction clutch means, for sliding windows of motor vehicles

Claim 1

IN A DRIVING MECHANISM FOR A SLIDING WINDOW OF A MOTOR VEHICLE, SAID MECHANISM HAVING A DRIVE CABLE CONNECTED TO THE WINDOW, AND A DRIVING WHEEL IN DRIVING ENGAGEMENT WITH SAID CABLE TO DISPLACE THE SAME IN OPPOSITE DIRECTIONS TO RAISE AND LOWER THE WINDOW, THE IMPROVEMENT COMPRISING A DRIVING UNIT INCLUDING A REVERSIBLE MOTOR AND REDUCTION GEARING, A FIRST SHAFT DRIVEN BY SAID MOTOR VIA SAID GEARING IN OPPOSITE DIRECTIONS, A SECOND SHAFT, MEANS CONNECTING SAID DRIVING WHEEL TO SAID SECOND SHAFT IN DRIVING RELATION, ONE OF SAID SHAFTS BEING HOLLOW, THE OTHER OF SAID SHAFTS BEING INSERTED IN THE LATTER SHAFT, AND FRICTION CLUTCH MEANS CONSTITUTED OF FLEXIBLE SHEET MATERIAL IN THE FORM OF A HOLLOW CYLINDRICAL BODY INTERPOSED BETWEEN SAID SHAFT AND PRELOADED TO BEAR UNDER INITIAL RADIAL STRESS AGAINST THE HOLLOW SHAFT FOR FRICTIONAL ENGAGEMENT THEREWITH AND ADAPTED FOR DRIVING ENGAGEMENT WITH SAID OTHER SHAFT FOR TRANSMITTING TORQUE OF LIMITED MAGNITUDE IN EITHER DIRECTION BETWEEN SAID SHAFTS, SAID CYLINDRICAL BODY BEING CONSITUTED OF AT LEAST ONE WINDING OF SAID MATERIAL AND HAVING RADIAL TERMINAL FACES AT OPPOSITE ENDS OF THE CYLINDERICAL BODY, SAID CYLINDRICAL BODY HAVING A NORMAL OUTER DIAMETER EXCEEDING THE INNER DIAMI ETER OF THE HOLLOW SHAFT, SAID BODY BEING INSERTED WITHIN AND URGED OUTWARDLY AGAINST THE INNER SURFACE OF THE HOLLOW SHAFT IN FRICTIONAL ENGAGEMENT, AND MEANS ROTATABLY SECURED WITH THE SAID OTHER SHAFT FOR ENGAGING RESPECTIVELY OF SAID TERMINAL FACES, DEPENDENT UPON THE DIRECTION OF ROTATION OF SAID FIRST SHAFT, TO DRIVINGLY ENGAGE THE SAID OTHER SHAFT AND THE CYLINDRICAL BODY TOGETHER FOR TRANSMITTING TORQUE OF SAID LIMITED MAGNITUDE BETWEEN SAID SHAFTS, SAID CYLINDRICAL BODY TENDING TO EXPAND IN DIAMETER AS TORQUE IS TRANSMITTED BETWEEN SAID SHAFTS DUE TO THE WINDING OF SAID BODY.