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. 07, 1992
Filed:
Sep. 14, 1990
Applicant:
Inventor:
Neil A Simpson, Aberdeen, GB;
Assignee:
Astec Developments Limited, Aberdeen, GB;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B21K / ; E21B / ;
U.S. Cl.
CPC ...
761082 ; 76DI / ; 76DI / ;
Abstract
A two-part investment casting process is described which involves first casting a hard material shell (32) such as stellite, which is threaded or profiled internally to allow attachment to a pre-machined shank (44) such that the advantages of a fluid and wear resistant investment casting of complex shape may be combined with a tough and machinable shank to allow attachment to the drill string.