Family of electric drills and two-speed gear box therefor
US4710071A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 16, 1986 |
| Grant date | Dec 1, 1987 |
| Priority date | — |
| Expiry date | May 16, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T408/96
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A two-speed gear box for handheld electric drills and the like has the movable parts associated with gear changing on or associated with a lay shaft. Gear changing is preferably effected by moving a pair of dogs, slidably mounted in holes through a lay shaft gear, to drivingly engage in either of two dog clutch members on the lay shaft. A thin flexible arm, preferably including a ring around the lay shaft, mounted in cantilever fashion from a movable base effects movement of the dogs. Should the dogs not be in proper register with a respective dog clutch member when changing speed, then the arm flexes and urges the dogs into driving engagement when proper register occurs. A family of two-speed drills having different specialized functions, e.g. a drill, a hammer drill, a screwdriver/drill, a screwdriver, etc., can be produced with the maximum parts in common enabling greater manufacturing flexibility and lower cost of manufacturing the family. Essentially the only parts different for different members of the family need be the gear box output shaft and the specialized function parts associated directly therewith. Advantageously, a family of battery operated tools can be provided in…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.