Drill and/or impact hammer

US5337835A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Ulrich Bohne · Dessau, DE
• Wilfried Kabatnik · Echterdingen, DE
• Manfred Bleicher
• Joachim Hecht · Magstadt, DE
• Justus Lamprecht · Dußlingen, DE

Key dates

• Filing date: Jun 25, 1993
• Grant date: Aug 16, 1994
• Expiry date: Jun 25, 2013

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B25D2250/021
• WIPO field: Machine tools
• WIPO sector: Mechanical engineering

Abstract

An impact hammer has a housing, a motor accommodated in the housing, an impacting mechanism accommodated in the housing and having a driver and a striker which is displaced by the driver in an axial direction and periodically strikes a shaft of a tool with the driver being tiltable about a tilting axis, a driving element which drives the driver into a reciprocating motion and a shaft which rotates the driving element. The driving element is provided with two interengaging eccentric parts including a first eccentric part which is non-rotatably connected with the shaft and a second eccentric part which is axially displaceable relative to the shaft. The eccentric parts have ring surfaces each surrounding the shaft, arranged asymmetrically relative to one another and being in contact with one another. The ring surfaces are offset relative to the one another so that a resulting eccentricity of the driving element relative to the shaft, which eccentricity acts on the driver, is adjustable between zero and a maximal value.