Patent ID: 9746115
Date: 2017-08-29
CPC Classifications: F16L

Claim:
1. A plug-in connection system for fluid lines, fittings, or assemblies, comprising a first coupling part, a second coupling part, and a holding element, the second coupling part being plugged into a receiving opening of the first coupling part along a central axis defined by the first coupling part, the holding element engaging one of the first and second coupling parts and being configured to latch with a counter-holding element formed on the other of the first and second coupling parts, wherein the holding element has a spreading surface which, by sliding relative to a counter spreading surface of the counter-holding element, causes a spreading movement of the holding element transversely with respect to the central axis along a spreading path during plugging in of the second coupling part with the first coupling part along an installation path, the spreading surface having a spreading contour facing the counter spreading surface and adapted to a counter contour of the counter spreading surface, the counter contour and the spreading contour engaging one another during insertion of the second coupling part into the first coupling part during an installation phase, such that the spreading path of the holding element changes in a non-linear manner depending on its position along the installation path, wherein in the installation phase includes a main installation phase between an initial installation phase and final installation phase, the main installation phase having a length traversed by the second coupling part along the installation path that is greater than another length traversed by the second coupling part along the installation path during at least one of the initial and final installation phases, and wherein the spreading contour of the spreading surface is configured to create an installation force increasing up to a maximum installation force in the initial installation phase that is generally maintained in the main installation phase and greater than an installation force in the final installation phase.