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.

Date of Patent:
Jul. 04, 1995

Filed:

Oct. 12, 1993
Applicant:
Inventors:

Llewellan Anderson, Renton, WA (US);

Thomas C Whitehouse, Puyallup, WA (US);

Assignee:

The Robbins Company, Kent, WA (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E21C / ; E21B / ;
U.S. Cl.
CPC ...
175230 ; 1753253 ;
Abstract

A down reaming apparatus has an upper stabilizer which supports the down reaming apparatus in the bored hole. A plurality of shoe assemblies are radially attached to the hub of the upper stabilizer. The shoe assemblies are biased against a bored shaft wall by pressurized cylinders which allow limited return movement with resistance of the shoe assemblies. A weight assembly comprising a plurality of stacked plates is secured to the frame of the down reaming apparatus and has manways therethrough which allow passage of workers. A lower stabilizer provides additional support for the down reaming apparatus. The lower stabilizer also includes shoe assemblies that are biased against the bored shaft wall by a pressurized cylinder.


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