Patent ID: 8876868

Claim:
A flange structure for guiding and advancing an inner member into an outer member having spaced arms along an axis in response to relative rotation between said inner member and said outer member about said axis and comprising: (a) an inner flange helically wound about and along said inner member; (b) a discontinuous outer flange helically wound about and along an opening in said outer member; (c) one of said inner and outer flanges being a lipped flange and having a lip projecting axially therefrom and extending therealong, said lip having an axial peak and a curvate surface; (d) the other of said flanges being a grooved flange and having a groove formed axially into said grooved flange and extending therealong, said groove having an axial trough and a curvate surface; and (e) said lipped flange and said grooved flange being configured in such a manner so as to radially interlock to resist radial splaying of the outer member arms relative to the inner member and so as to enable rotary joining of portions of said lip and said groove in response to said inner member being rotated relative to said outer member and being helically advanced into said outer member.