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:
Jun. 09, 1981
Filed:
Jan. 09, 1979
David Grenell, Laurelton, NY (US);
Allen-Stevens Corp., Woodside, NY (US);
Abstract
An elongated rectilinear tool for formation of a threaded hole in ductile metal by the coining or flowing of the metal. The tool typically is employed to form through threaded holes in a piece of ductile metal, and features a working end having a boring tip or drill point and a spade section having a flat shank with grooves in its lateral edges. The spade section holds the drill point and extends back a short distance from the working end. The diameter of the tool then enlarges slightly at a small inclined section which is followed by a longer coining tap section. The coining (flowing) of metal forms a thread on the previously smooth wall of the drilled hole, with peaks or crests, and roots. The lateral grooving of the spade section tracks, i.e. fits, into the fully formed threading as the present tool is screwed out. If the lateral grooves or notches for the spade section were not provided, then during removal of the tool from the threaded hole, the spade section of the drill portion would shear away the crests of the threads.