The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 23, 1993
Filed:
Nov. 13, 1992
James E Doherty, Barrington, IL (US);
Ernest J Wendling, Algonquin, IL (US);
James W Robinson, Mundelein, IL (US);
Illinois Tool Works Inc., Glenview, IL (US);
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.