Abstract: A power tool includes a motor and a motor switch movable between on and off settings. A transmission connects the motor to the tool holder of the power tool. The transmission includes a torque-responsive clutch arrangement which transmits torque below a preselected value in a first manner and torque above the preselected value in a different and distinguishable second manner. The torque-responsive clutch means undergoes an automatic change of torque transmission manner in response to a rise of transmitted torque past the preselected value. A turn-off arrangement mechanically detects the automatic change of the manner in which the clutch arrangement transmits torque and in response thereto automatically moves the motor switch from the on to the off setting. An override device is activatable by the user of the power tool for mechanically preventing the automatic turn-off arrangement from turning off the motor.
Type:
Grant
Filed:
January 28, 1976
Date of Patent:
May 9, 1978
Assignee:
Robert Bosch GmbH
Inventors:
Karl Roll, Alfred Hettich, Hubert Stahl, Werner Keil