Dual safety control means for a power tool
US3934657A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 1, 1974 |
| Grant date | Jan 27, 1976 |
| Priority date | — |
| Expiry date | Aug 1, 1994 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S415/904
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A safety control means for a portable power tool, such as a pneumatically driven hand grinder, wherein fluid supply and discharge passages are provided in the support handles of the tool and are respectively connected to the fluid inlet and outlet of the motor. First and second fluid control members are mounted in the handles on the upstream and downstream sides, respectively, of the fluid inlet and outlet of the motor. The first control member is movable to a first position preventing motive fluid from flowing through the supply passage and a second position permitting motive fluid to flow through the supply passage. The second control member is likewise movable to a first position preventing motive fluid from flowing through the discharge passage and a second position permitting flow through the discharge passage. A control lever is pivotally mounted on each of the tool support handles for effecting movement of the respective control members between their first and second positions. Start up and continuous operation of the tool is obtained only so long as both levers are grasped by the operator of the tool and retained in positions holding the control members in their second posi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.