US 12,320,378 B2
Shortened fastener with locally controlled thread height
Michael Garver, Glen Arbor, MI (US)
Assigned to MATHREAD INC., Wixom, MI (US)
Filed by MATHREAD INC., Wixom, MI (US)
Filed on Nov. 13, 2023, as Appl. No. 18/507,996.
Application 17/151,290 is a division of application No. 16/245,856, filed on Jan. 11, 2019, granted, now 10,927,877.
Application 18/507,996 is a continuation of application No. 17/151,290, filed on Jan. 18, 2021, granted, now 11,815,121.
Prior Publication US 2024/0077100 A1, Mar. 7, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. F16B 39/02 (2006.01); F16B 35/04 (2006.01)
CPC F16B 35/047 (2013.01) 12 Claims
OG exemplary drawing
 
1. A male anti-cross threading fastener comprising:
a substantially round shank having a lead end, a torque end, and a plurality of male threads around a circumference of the shank, the plurality of male threads comprising:
a standard thread around at least a portion of the circumference of the shank and having a standard thread contour defined by troughs at a minimum diameter, a flat crest at a major diameter, and flat flanks from the troughs to the crest having a width at a pitch diameter and a thread angle of about sixty degrees, wherein the major diameter of the standard thread is between a lower major diameter limit and a higher major diameter limit;
a transitional thread forming a continuous helix with the standard thread around at least a portion of the circumference of the shank and comprising a transitional thread contour defined by troughs, a flat crest, and flat flanks from the troughs to the crest and a thread angle of about sixty degrees and a height no higher than the lower major diameter limit of the standard thread contour, wherein the transitional thread winds less than about five-eighths of a turn (225 degrees) around the shank; and
an anti-cross thread forming a continuous helix with the transitional thread around at least a portion of the circumference of the shank and having an anti-cross thread contour comprising an outside diameter approximately the same as the pitch diameter of the standard thread, and wherein the anti-cross thread contour comprises a shape defined by a curve extending from a curve at a trough to about the outer diameter,
wherein the transitional thread contour has a crest that widens as the height transitions from the lower major diameter limit of the standard thread to the outside diameter of the anti-cross thread.