Patent ID: 9664226
Date: 2017-05-30
CPC Classifications: F16B

Claim:
1. An assembly unit having an assembly part which is penetrated by a bore and is to be fixed on a basic structure, having a shank, a head which protrudes radially beyond the shank and overlaps a bore edge in a radial manner and, on its end remote from the head, a fastening means which comprises a fixing portion and is held in a captive manner in the bore so as to be movable between a first axial position and a second axial position, wherein in the first axial position the shank protrudes from a bearing surface of the assembly part remote from the head at a maximum protrusion which comprises at least part of the fixing portion, and wherein in the second axial position the fixing portion does not protrude from the assembly surface or protrudes, however, at a protrusion that is reduced compared to the first axial position, and having a spring, which holds the fastening means in a captive manner in the bore, is fixed with its one spring end, close to the head, on the shank and with its other spring end, remote from the head, on the assembly part, is formed from a wound spring wire and encompasses the shank, the spring wire thereof being wound helically in such a manner that windings thereof do not overlap in the radial direction with reference to the spring axis), characterized in that the spring is arranged at least in part inside the bore of the assembly part and—the length of the spring in the maximum shortened state is dimensioned such that, in a final assembly state in which the assembly part is clamped with the basic structure, the head of the fastening means acts upon the maximum shortened spring in an axial manner and in this case at least a predominant part of a prestressing force of the fastening means is directed into the basic structure in the main force load by means of the spring.