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:
Jun. 07, 1983

Filed:

Dec. 08, 1980
Applicant:
Inventor:

Robert F Evans, La Habra, CA (US);

Assignee:

Other;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
E21B / ; E21B / ;
U.S. Cl.
CPC ...
175269 ; 175381 ; 175329 ; 175336 ;
Abstract

Abrasion cutting elements of a rotary drill bit are operatively connected to the bit body structure by means for yieldably supporting the abrasion cutting elements and for forcing them into a continuous drag mode of cutting contact with the earth formation. The drill bit may also employ compression or indentor cutting elements operatively attached in fixed operative positions. The yieldably supporting and force applying means may be hydraulically controlled by drilling fluid pressure and the cutting force applied on the abrasion cutting elements can be established independently of the axial cutting force transferred from the drill string and drill bit to the indentor cutting elements. Optimum performance of both the abrasion and indentor types of cutting elements is secured. The abrasion cutting elements are preferably retained for contacting and cutting the gage corner material. In drag bit applications, the means for yieldably supporting and applying force to the abrasion cutting elements may include a plurality of concentric removably retained sleeve members, each of which includes at least one ribbon spring leaf portion extending from the bottom of the sleeve member to support the abrasion cutting elements.


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