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.

Date of Patent:
May. 03, 2016

Filed:

Apr. 08, 2011
Applicant:

Franz-josef Püttmann, Lennestadt, DE;

Inventor:

Franz-Josef Püttmann, Lennestadt, DE;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
E21B 4/14 (2006.01); E21B 7/26 (2006.01); E21B 17/03 (2006.01); E21B 17/04 (2006.01);
U.S. Cl.
CPC ...
E21B 4/145 (2013.01); E21B 7/26 (2013.01); E21B 17/03 (2013.01); E21B 17/04 (2013.01);
Abstract

A ground-drilling device includes a basic body and a drill head movably mounted in relation thereto in the longitudinally axial direction, wherein a free space, which is variable in its size owing to the movable mounting, is formed between the drill head and the basic body, and a sealing element for sealing the free space with respect to the environment, wherein the sealing element is designed as a valve element which opens when an overpressure is present inside the clearance, in order to produce a pressure compensation, and which is closed when a negative pressure is present inside the clearance, in order to prevent a pressure compensation.


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