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:
Apr. 24, 1979
Filed:
Oct. 28, 1977
Lloyd L Garner, San Clemente, CA (US);
George R Herrick, Irvine, CA (US);
Charles R Harris, Whittier, CA (US);
Smith International, Inc., Newport Beach, CA (US);
Abstract
A rock bit for drilling hard formations has a bit body with a plurality of rolling cone cutters mounted on it for rotation with rotation of the bit body. The cutters each have a plurality of recesses in their outer surfaces and a tungsten carbide insert is interference fitted into each of said recesses. A large diameter rock bit has such inserts larger than about 3/4 inch diameter and a cavity is provided in the cylindrical base of such an insert. The cavity has a volume in the range of from about 15 to 30% of the volume of the cylindrical base and extends into the cylindrical base a distance of at least about 40% of the diameter of the base. The depth of the recess is more than half of the length of the portion of the insert that grips the recess in which it is inserted. Large savings in expensive tungsten carbide can be made without decreasing performance of the tungsten carbide inserts.