Such fastening elements are known from German Utility Models 1 997 148 and 76 36 365. These are so-called captive screws, which are to be inserted through a hole in a component and secured against falling out of the hole and being lost if the associated nut is lost. The elastic element is disposed behind the rear end of the threaded part and thus cooperates not with the associated nut but rather with the hole in the component.
The invention, by comparison, has to do with the assembly operation in making a screw connection. This term is understood very generally to mean screw connections, threaded pin connections, screw bolt connections, and the like. It also encompasses combinations and mixed forms of these fastening elements. A wide range of such threaded fastening elements are known from the prior art and are used to fasten or join parts to other parts, such as to join connectors, flanges or the like.
In the sense of the present invention, the threaded part is an axial portion of the fastening element having at least one male or female thread. The thread is a helical profiling of the circumferential surface of a pinlike or boltlike element or in a bore or opening, such as in a nut. The threads may for instance be trapezoidal, sawtooth, round or pointed threads or may have some arbitrary other profile cross section, and are used for fastening purposes and to transmit force and/or motion.
One problem in making threaded connections is that the pinlike fastening element, such as a screw, can slip out of the opening, such as the threaded bore, unless the first thread courses have entered into engagement. This is especially problematic if to make a connection, fastening or the like both hands are needed to hold parts, if tools are used, or if the assembly is done at places hard to access, with especially small fastening elements, or against gravity.