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. 04, 1992
Filed:
Aug. 03, 1990
Applicant:
Inventor:
Thomas A Newton, Jr, Houston, TX (US);
Assignee:
Other;
Primary Examiner:
Int. Cl.
CPC ...
E21B / ;
U.S. Cl.
CPC ...
175428 ; 175379 ; 175426 ; 407119 ;
Abstract
A preform cutting element for a rotary drill bit for use in drilling or coring holes in subsurface formations includes a cutting table 12, 13 of superhard material such as polycrystalline diamond. The rear face of the cutting table is bonded to a substrate 11 of less hard material, such as cemented tungsten carbide. A front portion 12 of the cutting table comprises a form of superhard material which is less wear-resistant than the superhard material forming the remainder 13 of the cutting table. The provision of the less wear-resistant superhard material at the front cutting faces reduces the tendency of the cutting table to spall.
Published as:
GB8917878D0; EP0411831A1; GB2234542A; IE902833A1; ZA906044B; US5135061A; GB2234542B; EP0411831B1; DE69007897D1; DE69007897T2; IE64060B1;