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:
Sep. 22, 1987
Filed:
Jan. 22, 1986
John D Barr, Cheltenham, GB;
NL Petroleum Products Limited, Gloucestershire, GB;
Abstract
A method of manufacturing by a power metallurgy process a rotary drill bit including a bit body having an external surface on which are mounted a plurality of preform cutting elements, and an inner passage for supplying drilling fluid to at least one nozzle located in a socket at the external surface of the bit. The method includes the steps of forming a hollow mould for moulding the bit body, packing the mould with powdered material, such as tungsten carbide powder, and infiltrating the material with a metal alloy in a furnace to form a matrix. Before packing the mould with the powdered material, there is positioned in the interior surface of the mould at least one former which projects into the interior of the mould space at the desired location for a nozzle socket, the former having an external screw thread whereby the matrix material packed around the former becomes shaped with a corresponding internal screw thread. The former is so constructed that it may be removed from the bit body after formation thereof to leave in the matrix an internally threaded socket which may receive a separately formed, externally threaded nozzle. The internal threads in the socket are formed from the matrix material which surrounds and defines the socket.