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:
Jun. 02, 1987
Filed:
Dec. 13, 1985
Wolfgang Lippacher, Herrsching, DE;
Werner Theissig, Munich, DE;
Hilti Aktiengesellschaft, Furstentum, LI;
Abstract
An electropneumatic hammer drill includes a housing containing a guide cylinder in which an exciter piston and a percussion piston are displaceably mounted in spaced relation with an air cushion formed between them. A hollow shaft encircles the guide cylinder within the housing and transmits rotary motion to a tool mounted in the hammer drill. A crankshaft for reciprocating the exciter piston via a piston rod is supported in two bearings located in the guide cylinder. The percussion mechanism for the hammer drill made up of the guide cylinder, the exciter piston, the percussion piston, the crankshaft and the piston rod form a subassembly. The subassembly can be inserted into and removed from the hammer drill as a unit.