Patent ID: 8608603

Claim:
A belt drive system comprising: a drive source for generating torque; a drive pulley, drivingly connected to the drive source, for outputting the torque of the drive source; at least one driven unit for performing a specified action upon input of the torque; a driven pulley, connected to the driven unit, for inputting the torque to the driven unit; a joint, interposed between the driven pulley and the driven unit to transmit the torque of the driven pulley to the driven unit, for stopping the torque transmission when receiving a load equal to or over a predetermined value, and wherein a belt contact surface of the driven pulley is covered with rubber that has been transferred to the driven pulley from the drive belt as a result of slippage between the drive belt and the driven pulley occurring from an increase in the input of torque required to drive the driven unit such that a coefficient of friction between the drive belt and the driven pulley increases due to a transfer of material from said contact surface of the drive belt to the driven pulley, thereby applying a load on the joint equal to or over the predetermined value necessary to stop the transmission of torque to the driven unit, and wherein the rubber is ethylene propylene diene terpolymer, and the rubber contains 10 to 20 vol % carbon.