Patent attributes
A plug-in coupling for removably interconnecting a first structural member and a second structural member comprises a resiliently deformable female coupling part adapted to be inserted into a socket at the first structural member such that it is retained therein. The female coupling part comprises a ball-shaped cup, an intermediate annular wall integral with said ball-shaped cup and serving as a guide portion, and a tubular external wall integral with said annular intermediate wall. The external wall surrounds at least a part of the ball-shaped cup in spaced relation thereto and engages a peripheral wall of the socket when the female coupling part is inserted into the socket. A male coupling part comprises a ball-shaped head and a fixing portion for securing the male coupling part to the second structural member. The intermediate annular wall of the female coupling part is of an undulated shape at least in a certain area thereof.