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:
Jul. 31, 2001
Filed:
Jun. 16, 1998
Applicant:
Inventors:
Franz-Josef Püttmann, Lennestadt, DE;
Gerhard Balve, Lennestadt, DE;
Assignee:
Tracto-Technik Paul Schmidt Spezialmaschinen, Lennestadt, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E21B 7/20 ;
U.S. Cl.
CPC ...
E21B 7/20 ;
Abstract
In apparatus for producing and expanding earth boreholes and for destroying and replacing underground pipelines or for driving in pipes, a feed drive and a rotary drive having a plug-in coupling comprising a chuck and a locking portion at the end of a string is located in a frame. The string comprises a plurality of sections or lengths having an internal screw thread at one end and an external screw thread on the locking portion at the other end, which at the same time is provided with a key face to hold fast said string section while it is screwed together with the next following string section.