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:
Aug. 28, 1990
Filed:
Jul. 28, 1989
Applicant:
Inventor:
Lars-Gunnar Lundell, Sandviken, SE;
Assignee:
Sandvik AB, Sandviken, SE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E21B / ;
U.S. Cl.
CPC ...
175410 ; 761082 ;
Abstract
A drill bit of the percussion type includes a bit body of steel, a front portion of which is provided with at least one slot in which an insert is attached by brazing. Brazed between the insert and side walls of the slot are side plates which are of uniform thickness while being thinner than the insert. The side plates are formed of cemented carbide or a metal alloy with a coefficient of linear expansion which for temperatures below 500.degree. C. is substantially smaller than that of steel and the braze metal while being approximately the same as that of the insert.