Torque limiting power screwdriver

US4458565A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Gunter Zilly · Echterdingen, DE
• Erich Borst · Echterdingen, DE
• Brigitte Hertell · Waldenbuch, DE
• Fritz Schadlich · Echterdingen, DE
• Heinz Walz
• Steffen Wunsch · Waldenbuch, DE

Key dates

• Filing date: Sep 29, 1982
• Grant date: Jul 10, 1984
• Expiry date: Sep 29, 2002

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B25B23/141
• WIPO field: Machine tools
• WIPO sector: Mechanical engineering

Abstract

A torque limiting power screwdriver includes a housing in which there is supported for rotation and axial displacement a screwdriver spindle. A transmission transmits power from a motor to the screwdriver spindle. A torque overload coupling and a separating coupling are interposed in the transmission, being operative for interrupting the transmission of torque from the motor to the screwdriver spindle. The separating coupling is coupled and uncoupled in response to axial displacement of the screwdriver spindle between its coupling and uncoupling positions. The axial movement of the spindle is accomplished by a trigger movably mounted on the housing and connected by a Bowden cable or a lever transmission to the spindle. The spindle is connected by an axially movable coupling with an output member, especially with a bevel gear transmission accommodated in an angular head housing portion. A switching trigger is used to energize and de-energize the motor. The trigger and the switching trigger can be combined into a trigger unit, thus making possible one-hand operation. The trigger and switching trigger are so constructed and arranged that they force the succession of energization of th…