Patent ID: 8057122

Claim:
An assembly unit adapted to be attached to a base structure, said assembly unit comprising: at least one assembly part with a through opening, and at least one fastener with a radially expanded head and a shaft that is provided with a fastening section, that extends through the through opening and is held captive therein, wherein: the shaft is encircled by a sleeve and the head of the fastener projects in a radial direction over this sleeve, wherein the frontal surface of the sleeve is at a distance to the head and forms a support surface when in a fully assembled position, which allows the fastener to come to rest on the base structure, wherein a radial distance exists between the sleeve and the shaft, the shaft is captivated inside the sleeve with axial mobility, the sleeve has an outer circumferential surface that defines two stop elements projecting from the outer circumferential surface, the stop elements arranged at an axial distance relative to each other, the stop elements including a first stop element and at a shorter distance to the head a second stop element, wherein the first stop element and the second stop element are located at fixed axial positions on the sleeve, an axial catch projects from the wall of the through opening, the axial catch defining a smaller inside diameter than the outside diameter of the stop elements, wherein the axial catch engages with the two stop elements to retain the sleeve inside the through opening, and the axial catch defines a width along the axial direction that is less than the axial distance between the two stop elements to permit axial sliding of the sleeve while retained within the through opening, the axial catch and the stop elements are embodied such that they can be moved past each other in axial direction, under elastic or elastic and plastic deformation, the axial catch inside the through opening and the second stop element on the outer circumferential surface are respectively arranged in an axial position, which ensures that when in a pre-assembly position where the second stop element rests against a stop surface of the axial catch that is facing the head, the fastening section is arranged in a specific axial position relative to the surface of the assembly part that is facing away from the head and defines the assembly surface, when in the fully assembled position, the second stop element is located on the side of the axial catch that is facing away from the head.