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. 14, 1993
Filed:
Jan. 07, 1992
Applicant:
Inventor:
Joseph F Dickson, Jefferson, MA (US);
Assignee:
Quamco, Inc., Holden, MA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B21H / ;
U.S. Cl.
CPC ...
72 88 ; 72469 ; 72103 ;
Abstract
A method of producing threaded fasteners, particularly screws characterized by a thread root which is substantially wider than the thread crest, which results in seam free threads. The method employs a rolling die with a novel double form thread profile geometry wherein the angle of divergence of the groove defining walls gradually varies between an obtuse pointing angle and an acute finish angle as the groove depth increases from a sorting depth to the finish depth. The finish form of the die is maintained for a length which is commensurate with at least two and one-half revolutions of the fastener which is being formed.