Rotary hammer
US6227309A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 9, 2000 |
| Grant date | May 8, 2001 |
| Priority date | — |
| Expiry date | Feb 9, 2020 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB25D2250/365
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A rotary hammer which comprises a tool holder (2), an air cushion hammering mechanism which comprises a piston (9) and a beat piece (21) slideably located in a cylinder (8') so that reciprocation of the piston in the cylinder will cause the beat piece to hit a tool located in the tool holder; and means for causing the cylinder to rotate in addition to, or instead of, reciprocation of the piston in order to cause a tool located in the tool holder to rotate. The piston (9) is formed from a plastics material and is sealed in the cylinder (8') by an annular seal (27) that is located within an annular groove (26) in the piston. The annular seal has an inner diameter that is greater than the diameter of the radially outwardly directed surface of the groove, and the groove has an axial dimension that is greater than that of the annular seal, so that when the cylinder rotates about the piston (without reciprocation of the piston) the seal (26) will rotate with the cylinder (8').
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.