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:
Aug. 10, 1993
Filed:
Mar. 12, 1992
Applicant:
Inventor:
Alfons Hesse, Lennestadt, DE;
Assignee:
Tracto-Technik Paul Schmidt Spezialmaschinen KG, Lennestadt, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
E21B / ;
U.S. Cl.
CPC ...
175 19 ; 173136 ;
Abstract
In a percussion mach in particular a self-propelled ram boring machine, with a percussion piston which is axially movable in the machine housing, has a hollow piston rod and is acted on by a pressure medium via a supply hose connected to the rear end of the housing, a piston rod bore communicates with the pressure medium supply when the percussion piston is in the front end position and communicates with a discharge opening when the percussion piston is in the rear end position.