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:
Jan. 11, 2000
Filed:
Oct. 30, 1998
David J Hicks, Tulsa, OK (US);
TDW Delaware, Inc., Wilmington, DE (US);
Abstract
A machine for use underwater and therefor subject to ambient hydrostatic pressure for tapping a pressurized pipeline has an elongated tubular tapping machine body with a boring bar therein that receives a cutter at its lower end. A passageway in a lower end portion of the tapping machine body senses the internal pressure of a pipeline after the pipeline is penetrated by the cutter, the passageway being connected to a pressure equalizer having communication with the interior of the tapping machine body to thereby balance hydraulic forces applied to the boring bar during a tapping operation. The machine has a gear case affixed to the tapping machine body to actuate the boring bar, the tapping machine body being sealed from the gear case, and including a fluid isolating equalizer supported to the tapping machine body and having a first communication with the interior of the gear box and a second communication with ambient hydrostatic pressure to thereby at least substantially equalize pressure in the gear box with the ambient hydrostatic pressure.