Demolition hammer and/or hammer-drill with a percussion device suitable for releasing clamped objects by striking
US6923269B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 8, 2002 |
| Grant date | Aug 2, 2005 |
| Priority date | — |
| Expiry date | May 8, 2022 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB25D17/086
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
The invention relates to a demolition hammer and/or hammer drill comprising a percussion generating device having a percussion piston moving axially back and forth. In a main percussion mode, the percussion piston impinges upon a tool which can move along a limited axial path straight into a main percussion direction. In a free percussion mode, the percussion piston indirectly impinges upon a percussion changing device, and by means thereof upon the tool, in a free percussion direction opposite to the main percussion direction. The impact surface of a tool shaft and the impact surface of a free percussion ram are placed opposite an impact surface of the percussion piston in such a way that the free percussion ram is removed from the effective area of the percussion piston by a return spring in the main percussion position. Under the effect of the return spring, the percussion ram is simultaneously supported on a gear member of the percussion changing device, which projects with an extension into the motion path of a stop surface provided in the tool. The stop surface reaches the extension when it has moved away from the effective area of the percussion piston in an idle running sta…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.