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:
Sep. 22, 1992

Filed:

Sep. 27, 1991
Applicant:
Inventor:

Donald R Greenlee, Cedar Hill, TX (US);

Assignee:

Dresser Industries, Inc., Dallas, TX (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E21B / ; E21B / ;
U.S. Cl.
CPC ...
166134 ; 166140 ; 166216 ; 166217 ;
Abstract

A releasable boring mechanism for releasably securing a tool downhole in a well includes upper and lower sets of slip expandable radially outward from retracted positions into extended positions for engagement with the inside wall of a well casing when a mandrel attached to a tubing string casing, the anchoring mechanism is lifted to wedge upper and lower frustoconical heads between the mandrel and the slips. In releasing the slips from the well casing, the lower edge of a window in an upper slip cage first engages a primary release shoulder on the bottom of a first to release one of the slips to lift such slip through the application of compression forces from the casing well.


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