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:
May. 25, 1993
Filed:
Oct. 10, 1991
Hans Gschwend, Mauren, CH;
Markus Sprenger, Eschen, LI;
Hilti Aktiengesellschaft, , LI;
Abstract
A portable, internal combustion power operated working device, such as a setting tool for driving fastening elements into a receiving material, has a combustion chamber (9) for burning an air-fuel mixture. A piston (7, 7a), guided within a guide cylinder (8), is driven by the gas pressure generated by the combustion of the air-fuel mixture. The combustion chamber volume can be varied by at least one displaceable combustion chamber wall (11). To prepare the air-fuel mixture, a metering chamber (67) holds a predetermined quantity of gaseous fuel. Fuel from the metering chamber along with air is drawn into the combustion chamber by a negative pressure produced in the combustion chamber when the combustion chamber volume is increased by displacing the at least one combustion chamber wall (11).