Fuel system for combustion-powered, fastener-driving tool
US5263439A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 13, 1992 |
| Grant date | Nov 23, 1993 |
| Priority date | — |
| Expiry date | Nov 13, 2012 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB25C1/08
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
For use in a combustion-powered, fastener-driving tool having a combustion chamber, a source of a combustible fuel, and a switch that must be closed to enable the tool, a fuel system comprises a fuel injector, which includes a normally closed, solenoid-energized valve between the fuel source and the combustion chamber, and an electronic circuit responsive to the switch for energizing the solenoid to open the valve when the switch is closed and for deenergizing the solenoid after a time interval. A resistive-capacitive network defining the time interval includes a first resistor, a second resistor arranged to be selectively connected in parallel therewith, a thermistor connected in parallel therewith, and a variable resistor connected to the parallel resistors. Another network effects a time delay between closure of the switch and energization of the solenoid. Optionally, another network varies the time interval in response to ambient pressure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.