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:
Feb. 17, 1981
Filed:
Mar. 30, 1979
Applicant:
Inventor:
Paul Schmidt, 5940 Lennestadt, DE;
Assignee:
Other;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
E21B / ;
U.S. Cl.
CPC ...
173 91 ; 175 19 ;
Abstract
A self-propelled pneumatic ram boring device for boring holes in the ground comprises a percussion piston which is reciprocable in a housing, and a control sleeve which controls the forward and rearward movement of the piston by passing over radial control ports in the piston. In order to control the device to move either forwards or rearwards, without having to twist a hose which supplies air to the device as is usual, the control sleeve is rigidly fixed in position in the housing and has control ports to which air is supplied or not under the control of valve members and which are themselves remotely controlled by a second compressed air supply to the device, or electrically.