Electric tool
US8449425B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 31, 2010 |
| Grant date | May 28, 2013 |
| Priority date | — |
| Expiry date | Apr 15, 2030 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB25F5/001
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
One aspect of the invention includes a speed changing device which can be switched from a high-speed low-torque output state to a low-speed high-torque output state. In the high-speed low-torque state, a second stage internal gear rotates together with a first stage carrier. The low-speed high-torque output state is caused as the second stage internal gear is disconnected from the first stage carrier so as to be restricted from rotating. The timing of resetting the speed changing device is shifted relative to the timing of stopping the electric motor by an OFF operation of the switch lever with a delay mechanism, so that the second stage internal gear is engaged with the first stage carrier after the rotation through inertia is stopped, whereby its impact is reduced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.