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:
Sep. 16, 1980
Filed:
Jul. 19, 1979
Applicant:
Inventor:
Franz Chromy, Levis, AT;
Assignee:
Hilti Aktiengesellschaft, Schaan, LI;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B25D / ; B25D / ;
U.S. Cl.
CPC ...
173116 ; 173 14 ;
Abstract
In a hammer drill, a drive piston is reciprocated by a motor, and, over a pneumatic buffer, the reciprocating motion is transmitted to a percussion piston. A throttle valve regulates the flow of a fuel mixture to the motor for controlling its operation. A membrane switch connected to and operated by the pressure conditions within the pneumatic buffer controls the throttle valve.