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. 20, 1983
Filed:
Sep. 15, 1981
Applicant:
Inventor:
Edward S Mumby, Carmichael, CA (US);
Assignee:
Exploration Logging, Inc., Sacramento, CA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E21B / ;
U.S. Cl.
CPC ...
175 48 ; 251137 ;
Abstract
A monostable, solenoid-operated valve in a passage which bypasses the drilling fluid pressure drop across a drill bit at the lower end of a drill string in a well opens and closes in response to downhole conditions to create pressure pulses in the drilling fluid. The valve is urged toward a closed position by drilling fluid pumped through the drill string. A larger force is required to open the valve than to hold it open. Current supplied to the solenoid to open the valve is thereafter reduced to a value sufficient to hold the valve open. The solenoid is de-energized to close the valve.