Hammer drill with camming hammer drive mechanism

US7350592B2 · kind B2 · utility

Assignee

• BLACK & DECKER INC. · US

Inventors

• Norbert Hahn · Franklin, US
• Ernst Staas · Limburg, DE
• Achim Buchholz · Limburg, DE
• Michael Stirm · Oberursel, DE
• Ralf Bernhart · Idstein, DE

Key dates

• Filing date: Feb 9, 2006
• Grant date: Apr 1, 2008
• Expiry date: Feb 9, 2026

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B25D2250/371
• WIPO field: Machine tools
• WIPO sector: Mechanical engineering

Abstract

A reciprocating drive mechanism for a striker in a hammer, a rotary hammer, or a power drill having a hammer action, includes a sinusoidal cam channel formed on a drive member and a cam follower, in the form of a ball bearing, attached to a driven member which, due to the interaction of the cam and cam follower, results in a reciprocating movement of the driven member. Both the drive member and driven member can be rotatingly driven by a motor, their relative speeds resulting in the reciprocating movement of the driven member. The driven member is connected to the striker either via a mechanical helical spring or an air spring.