Fastening device for use on threaded bolts or studs

A fastening device for connection to an associated threaded bolt comprising:

• a molded plastic body having an inwardly extending opening with an entrance end sized to receive the associated bolt;
• at least one resilient elastic catch projection member mounted on said opening adjacent said entrance end and extending radially and axially inward relative to said entrance end, said at least one catch projection member terminating in a free end lying at a diameter significantly less than the diameter of the associated bolt;
• a series of graduated forms formed on a radially inward facing surface of said catch projection member and adapted to engage between adjacent threads of the associated bolt as said bolt is moved axially into said opening and said catch projection is deflected radially outward;
• said graduated forms comprising step-like protuberances formed such that when said elastic catch projection member is in its undeflected position each successive protuberance inwardly of said entrance end lies progressively closer to the axis of said opening and is defined by a pair of intersecting faces which respectively lie in planes generally perpendicular and parallel to the axis of said opening;
• and,
• at least one guide rib formed in said opening to extend parallel to said at least one catch projection member.