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:
Apr. 16, 2002
Filed:
Dec. 15, 1999
Applicant:
Inventors:
Alfons Hesse, Lennestadt, DE;
Franz-Josef Püttmann, Lennestadt, DE;
Assignee:
Tracto-Technik - Paul Schmidt - Spezialmaschinen, Lennestadt, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E21B 4/14 ;
U.S. Cl.
CPC ...
E21B 4/14 ;
Abstract
In a ram drilling tool for producing bores in the ground and having a percussion piston which is moved to and fro in a casing, a control sleeve is guided such that it can be displaced on a control pipe projecting into a percussion-piston chamber and whose axial position determines the direction of movement of the tool. In order to permit the movement to be reversed, a control chamber connected to a control-air line is arranged between the control pipe and the control sleeve, and its front end terminates flush with a collar at the front end of the control pipe.