Switch-brake interlock for chain saw
US4335514A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 8, 1980 |
| Grant date | Jun 22, 1982 |
| Priority date | — |
| Expiry date | Aug 8, 2000 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T83/099
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A shut-off device (104) controlling the operation of the motive means such as an electric motor which powers a tool such as a chain saw (12) having a housing (14) with a brake (34) therein operative to stop the chain saw (12). The shut-off device (104) includes a switch (54) biased off and shiftable on. A pivotable or shiftable trigger (72) is shifted toward but remains out of contact with the switch (54). A link (92) is caused to shift responsive to the brake (34) when the brake becomes operative, but the link is otherwise disposed intermediate the switch (54) and the trigger (72) to permit the trigger (72) movement to actuate the switch (54). However, on brake actuation the link is removed from a path of motion between the switch (54) and trigger (72) thereby to restore the switch (54) to "off" position. Once the link (92) is removed from the path of motion it cannot be reinserted therein until after the trigger (72) is released. The housing (14) may include a fulcrum (66) and/or a post (68) to guide the link (92) movement. The link (92) may include a bend (102) to permit limited deflection thereof, or have a second link or holding member (112) positioning the link (92) responsiv…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.