Patent ID: 6712574
Filing Date: 2004-03-30
Classification: F16B

Abstract:
A quick insertion fastener of the type having an internally threaded first member adapted to be quickly attached and tightened on an externally threaded second member inserted therein, wherein the first member comprises:(a) a casing having an internal surface at a front part thereof in a frusto-conical shape with a taper angle â€œ&agr;â€ , said front part of the casing being oriented toward the second member for insertion thereof; (b) a plurality of shell segments radially arranged on a fastener axis to form a displaceable shell assembly contained in said casing, each of said shell segments having a similar shape with an external surface at a front end thereof tapered in a frusto-conical shape with a taper angle â€œ&agr;â€  corresponding to the taper angle of the internal front surface of said casing and internal threads having a thread height â€œhâ€  and pitch â€œpâ€ ; (c) a spring member positioned at a rear part of said casing which is arranged to provide an elastic force to elastically retain rear ends of the shell segments to be axially moveable in said shell assembly; and (d) an end retainer provided at the rear part of said casing having a taper engaging the rear ends of the shell segments so as to displace them radially as they are moved axially such that the shell segments are spread apart radially to allow insertion of the second member past the internal threads of the shell segments upon insertion of the second member into the front part of said casing and toward the end retainer at the rear part of said casing.