Patent ID: 11883081
Assignee: RTG SCIENTIFIC, LLC
Field: Medical technology (Instruments)
Classification: CPC A  B | IPC A  B

Claim 7:
8. A fastener comprising:
a shaft comprising:
a minor diameter;
a proximal end;
a distal end; and
a longitudinal axis; and

a plurality of helical threads disposed about the shaft along the longitudinal axis between the proximal and distal ends of the shaft, the plurality of helical threads comprising:
a first helical thread comprising:
a first concave undercut surface open toward the proximal end of the shaft; and
a first convex undercut surface facing toward the distal end of the shaft; and

a second helical thread comprising:
a second concave undercut surface open toward the distal end of the shaft; and
a second convex undercut surface facing toward the proximal end of the shaft;

wherein, when the fastener is viewed in section along a plane containing the longitudinal axis of the shaft:
the first concave undercut surface and the first convex undercut surface of the first helical thread each extend from the minor diameter of the shaft to a first crest of the first helical thread;
the second concave undercut surface and the second convex undercut surface of the second helical thread each extend from the minor diameter of the shaft to a second crest of the second helical thread;
a first interlocking space is formed intermediate the first concave undercut surface and the second concave undercut surface;
a second interlocking space is formed intermediate the first convex undercut surface and the second convex undercut surface; and
at least one of:
the first helical thread does not have mirror symmetry with itself across any plane perpendicular to the longitudinal axis of the shaft; and
the second helical thread does not have mirror symmetry with itself across any plane perpendicular to the longitudinal axis of the shaft.