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:
Dec. 11, 1990
Filed:
Jul. 10, 1989
Applicant:
Inventors:
Jan-Gunnar Hedlund, Sandviken, SE;
Bengt A Asberg, Gavle, SE;
Assignee:
Sandvik AB, Sandviken, SE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E21B / ; E21C / ;
U.S. Cl.
CPC ...
299 81 ; 175393 ;
Abstract
A tool is mounted in a holder, the holder including a fluid passage for discharging drilling fluid toward a cutting zone. Fluid flow is regulated by a valve in the holder. The valve includes a housing and a valve element movable in the housing. The valve element opens the valve in response to rearward displacement of the tool relative to the holder. The housing of the valve is also rearwardly displaceable relative to the holder whenever rearward forces transmitted from the tool are excessive, thereby avoiding the occurrence of damage to the valve. The valve housing is yiealdably biased forwardly by fluid pressure in the conduit.