Releasable plug coupling with protective sleeve

Abstract

The releasable plug coupling is used for connecting fluid lines, particularly, fuel lines of motor vehicles. The plug coupling comprises a tubular plug-in part ( ) with an annular retaining lip ( ) as well as a coupling housing ( ) with a cylindrical receiving space ( ) for inserting the plug-in part ( ) and a separate retaining element ( ) with elastic retaining edges ( ) that project radially into the receiving space ( ) and that grip behind the retaining lip ( ) after the plug-in part ( ) is inserted into the receiving space ( ). The retaining edges ( ) are attached to support bodies ( ) that are connected at their ends by elastic connecting pieces ( ) that form a V to pressure plates ( ). These plates extend outwards through corresponding openings ( ) in the housing wall ( ) and are pressed together from the outside for releasing the coupling. On the head part ( ) of the coupling housing ( ) there is a protective sleeve ( ) that can move axially and that covers the pressure plates ( ) when the plug-in part ( ) is inserted in order to prevent unintentional release of the coupling. This protective sleeve ( ) is integrally connected by a radial connection ring ( ) to an inner guidance sleeve ( ) that, in turn, is connected at their free inner edge ( ) by two opposing connecting pieces ( ) to a ring ( ). This has the effect that the retaining lip ( ) pushes against the ring ( ) when the plug-in part ( ) is inserted and thus, the protective sleeve ( ) is automatically moved by the retaining ring ( ) over the pressure plate ( ). Between the connection ring ( ) and the front wall ( ) of the housing head ( ), there is a spiral spring ( ) that keeps the protective sleeve ( ) ready for movement.