Motor-driven hand tool with braking torque device
US4871033A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 23, 1989 |
| Grant date | Oct 3, 1989 |
| Priority date | — |
| Expiry date | Jan 23, 2009 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16D67/02
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
In a motor-driven hand tool, such as a drill, an inert mass is rotatably supported in a housing and is connected to the housing by a spring encircling a driven shaft mounted in the housing. The driven shaft is arranged to rotate a drill bit secured to the shaft. If the driven shaft is prevented from rotating and the housing rotates relative to the shaft, the spring tightens about and grips the driven shaft exerting a braking torque on it. The braking torque reduces the reaction torque required of the tool operator and affords a more rapid release of an overload clutch acting on the driven shaft. The overload clutch is formed by a collar, a gear wheel, a cup spring, and an adjustable ring nut, all located on the driven shaft.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.