Trigger valve and safety mechanism for fastener driving tool
US5080273A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 19, 1989 |
| Grant date | Jan 14, 1992 |
| Priority date | — |
| Expiry date | Dec 19, 2009 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB25C1/043
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A pneumatically operated fastener driving tool having a pivotally mounted magazine. The displacement of the magazine is used to actuate the tool when the nosepiece is in engagement with a workpiece. With the magazine travel kept to a minimum, the magazine is coupled to a cam lever which amplifies the displacement of the magazine. One portion of the cam lever is in engagement with a trip lever which forms a bearing surface for the trigger valve cartridge, which enables the tool when the magazine is in a drive position. The geometry of the cam lever causes a relatively greater displacement of the trip lever than the displacement of the magazine. The fastener driving tool also includes a poppet valve for controlling the compressed air flow into the drive cylinder. The top portion of the poppet is subject to the compressed air reservoir within the tool. A poppet chamber disposed at the bottom of the poppet controls the opening and closing of the poppet valve. An important aspect of the invention are the throttling inlet and exhaust passageways to the poppet chamber which allow the pressure in the poppet chamber to be controlled, thus reducing poppet flutter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.