Hand-held power tool

US4276941A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Karl Wanner · Echterdingen, DE
• Werner Lehmann · Leinfelden, DE
• Ulrich Ranger · Leinfelden, DE

Key dates

• Filing date: Aug 13, 1979
• Grant date: Jul 7, 1981
• Expiry date: Aug 13, 1999

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B25D2217/0088
• WIPO field: Machine tools
• WIPO sector: Mechanical engineering

Abstract

A hand-held power tool has a tool holder for holding a tool, a striking mechanism including a cylindrical sleeve, a drive piston reciprocable in the sleeve, and a striker actuated by the latter, and a drive motor located axially parallel with and laterally adjacent to the cylindrical sleeve. The drive motor transmits the movement to the striking mechanism through a crank drive which is a one-stage crank drive and has a drive train extending transversely to a longitudinal axis of the cylindrical sleeve. The crank drive includes a rotatable shaft, a bevel gear fixedly mounted on one end portion of the drive shaft and meshing with a drive pinion of the motor, and a crank lever mounted on the other end portion of the drive shaft and connected with the drive piston of the striking mechanism. A fan is mounted on the motor shaft and operative for aspirating air, so that air flows through the motor, then flows around the cylindrical sleeve of the striking mechanism and then discharges toward the tool holder.