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:
Nov. 17, 1992
Filed:
Sep. 27, 1991
Applicant:
Inventors:
Faisal J Yousef, Houston, TX (US);
Robert F Kane, Houston, TX (US);
Joel Ham, Cypress, TX (US);
David Mildren, Houston, TX (US);
Assignee:
Sandvik Rock Tools, Inc., Bristol, VA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E21B / ; F16B / ;
U.S. Cl.
CPC ...
175320 ; 175415 ; 285334 ; 411366 ; 411414 ;
Abstract
A driver sub and a case for enclosing a piston chamber of a percussion drill are threadedly connected by respective identical male and female screw threads. Each of the identical male and female screw threads includes a root portion, the shape of which is defined by portions of two axially overlapping ellipses interconnected by a flat.