US 7,458,759 B2
Threaded fastener with dual reinforcing leads for facilitating manufacture of the fastener, thread rolling die for forming the threaded fastener, and method of manufacturing the threaded fastener
Kenneth R. LeVey, West Chicago, Ill. (US)
Assigned to Illinois Tool Works Inc., Glenview, Ill. (US)
Filed on Dec. 18, 2002, as Appl. No. 10/323,265.
Prior Publication US 2004/0120790 A1, Jun. 24, 2004
Int. Cl. F16B 33/02 (2006.01)
U.S. Cl. 411—412 7 Claims
OG exemplary drawing
 
1. A threaded fastener formed from a blank member by means of thread rolling dies manipulated in accordance with a thread rolling process, comprising:
a shank portion having an axial extent defined around a longitudinal axis;
a first, primary thread lead defined upon said shank portion and comprising a plurality of first, primary threads which are successively defined upon said shank portion at positions which are spaced from each other by first predetermined axially spaced pitch distances, wherein each one of said first, primary threads also has a predetermined root diameter and a predetermined crest diameter; and
a dual set of second, auxiliary thread leads defined upon said shank portion and comprising a plurality of pairs of second, auxiliary threads which are disposed adjacent to each other, wherein said pairs of second, auxiliary threads are successively defined upon said shank portion at positions which are interposed between said successive ones of said plurality of first, primary threads, wherein said pairs of second, auxiliary threads are spaced from each other by second predetermined axially spaced pitch distances, and wherein each one of said second, auxiliary threads is axially spaced from each other by a third predetermined axially spaced distance which is less than a fourth predetermined axially spaced distance, defined between each one of said second, auxiliary threads and an adjacent one of said first, primary threads, so as to facilitate the definition of said first, primary thread lead, comprising said plurality of first, primary threads, upon said shank portion, each one of said second, auxiliary threads also having a predetermined root diameter that is substantially the same as said predetermined root diameter of each one of said first, primary threads, and a crest diameter that is substantially less than said predetermined crest diameter of each one of said first, primary threads.