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. 21, 1999
Filed:
Apr. 29, 1997
Tracto-Technik Paul Schmidt Spezialmaschinen, Lennestadt, DE;
Abstract
In a percussion drill apparatus for soil drilling with a percussion piston which is moving to and fro within a housing, a control sleeve is mounted on a control tube which protrudes into the percussion piston chamber, the axial position of which determines the direction of movement of the apparatus. In order to make a reversal of movement possible a reversing chamber is connected with a control air line which runs inside the control tube and an approach chamber is connected by way of a drilling with the interior of a control tube which feeds the operating air into the percussion piston chamber. Consequently the control sleeve is moved into one direction with the aid of the control air and in the other direction with the aid of the operating air.