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. 26, 1989
Filed:
Jul. 22, 1988
J C Birdwell, Houston, TX (US);
Other;
Abstract
For use in a measuring while drilling (MWD) apparatus, a variable drilling fluid flow orifice including circular valve seat and valve element in the fashion of a plug is disclosed. The plug is positioned on a stem which connects with a piston in a chamber, the chamber divided into two portions. Pressure is applied on both sides of the piston to provide a pressure balance. Moreover, the flow to the chamber is determined by a pump connected with a first valve means. The first valve means has two outlet lines which connect through first and second feed lines to the piston and chamber. The pump is isolated within a housing surrounded by an annular fluid flow path for drilling fluid. In the housing, a sealed chamber is included for hydraulic fluid for operation of the pump, and the first valve means is controlled by an electrical solenoid connected with a valve stem for moving valve elements of the first valve means to control fluid flow and thereby move the plug in the circular valve seat.