Abstract: An anti-unscrewing device for coupling the tubular ends of two components in fluid conveying or delivery systems by means of a threaded ring nut that can be screwed to one of said tubular ends to connect said ends, wherein said anti-unscrewing device comprises a connecting portion to connect the device to one of the components and at least one counter element provided with an engaging portion suitable to engage a corresponding engaging surface formed at said ring nut, such that the engaging portion can be displaced by means of a movement of the ring nut. There are further provided guide means dictating a movement path for the counter element, such that an unscrewing movement of the ring nut will cause the engaging portion to move to a locking position relative to the ring nut thereby preventing the ring nut from unscrewing.

Abstract: A fastener system for retaining a loose elongate fastener in a counterbore, including an elongate fastener, such as a bolt, having a head for being received and retained in a counterbore in a structure and in generally flush relation to a surface of the structure surrounding the counterbore, and a retaining member for being secured to the structure proximate the counterbore and overlapping the counterbore to trap the loose fastener in the counterbore.

Abstract: A two member threaded fastener includes integral ribs and/or locking fingers formed concentrically around threaded portions of the two members which make up each fastener. The ribs and/or locking fingers interferingly interengage one another as the two members are threadedly intermated to either removably or permanently lock the members together as desired for a given application. Preferably, the locking fastener members are formed of a polymeric resin and include concentric annular rings which are spaced from the threaded portions of the fastener members by interconnecting webs and define axially extending ribs. The ribs are rounded and preferably sinusoidal for removably locking fastener members and are serrated for permanently locking fastener members.