Fastening device

Claim 1

An improved fastening device (70, 72, 74, 76, 78) for securement with an externally threaded member ("S"), said device of the type having a base member (12), an aperture (40) through the base member for receiving the threaded member, thread engaging means defined by marginal portions (16, 16a) of the aperture which extend outwardly from the base member for engagement with a lower surface (62, 62a) of a thread of the threaded member when initially inserted through the aperture, a pair of resilient finger portions (30, 32) made integral with and extending upwardly and angularly inwardly from the base member on opposite sides of the aperture, said finger portions extending radially inwardly towards one another in overhanging relationship relative to the thread engaging means and having free-ends (34, 36) respectively thereof that are spaced-apart from each other along an axis ("y--y") defined therebetween and are axially off-set relative to one another such that the free-end of the one of the finger portions is higher than the free-end of the other finger portion relative to the base member, said thread engaging means including an upwardly projecting generally frusto-conical projection (14) defining upper and lower generally helical edges (16, 16a) separated by a slot portion (38) formed radially relative to the aperture in the base member, said space between the finger portion free-ends and said base member aperture edges dimensionally adapted so that, upon turning the threaded member through the aperture, a force is imparted by the threaded member to intially draw the edges downwardly and axially into engagement with the lower thread surface and pivot the finger portions radially inwardly into engagement with an upper surface (60, 60a) of the threaded member so that a counter-force is imparted by the threaded member to pivot the finger portions in generally opposite directions and draw the edges downwardly and axially inwardly to urge the finger portions and the edges into tight gripping engagement with the root portions of the threaded member with the axial distance between corresponding axially aligned on the edges and the free-ends of the finger portions substantially greater than in the intially installed position thereof, said improvement characterized by the slot portion extending radially outwardly from the aperture along the base member and thence along the finger portion having the higher free-end relative the base member in a direction that is substantially transverse to the axis defined between the finger portion free-ends to provide the device with improved ability to receive and effectively secure the threaded-member without cocking or cross-threadably engaging the threads thereof.