Power-driven hammer drill having an improved operating mode switch-over mechanism
US6176321A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 14, 1999 |
| Grant date | Jan 23, 2001 |
| Priority date | — |
| Expiry date | Sep 14, 2019 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB25D2216/0038
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A power-driven hammer drill 1 includes a rotary lever 8 for transmitting and disabling the transmission of the rotation of a motor 5 to a tool bit 4 and a slide lever 9 for transmitting and disabling the transmission of hammer blows to the tool bit 4. The rotary lever 8 is formed with a chamfer 52, whereas the slide lever 9 is formed with a straight portion 54 and a cut-out 53 which conforms to the circular edge of the rotary lever 8. When the slide lever 9 is in the lowermost position with the rotary lever 8 fitted in the cut-out 53, the rotary lever 8 is in the position to disconnect the rotation of the motor 5 to the tool bit 4, and while in this position, the slide lever 9 cannot be slid to its uppermost position, in which hammer blows cannot be transmitted to the tool bit 4. When the slide lever 9 is located in the uppermost position and the chamfer 52 of the rotary lever 8 is in the rearmost position, in which hammer blows cannot be transmitted to the tool bit 4 but rotation can be transmitted to the tool bit 4, the straight portion 54 opposes the chamfer 52 across a narrow gap so that the rotary lever 8 cannot be rotated to the rotation disabling position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.