Patent ID: RE39439

Claim:
A system for providing a joint between adjacent building panels, comprising: each of said building panels including a first edge and a second edge such that the first edge of each of said building panels forms a first mechanical connection with the second end of an adjacent one of the building panels locking the first and second edges of the building panels to each other in a first direction at right angles to a principal plane of the panels, and a locking device arranged on a rear side of the building panels forming a second mechanical connection locking the building panels to each other in a second direction parallel to the principal plane and at right angles to the first and second edges, said locking device fitting within a locking groove extending parallel to and spaced apart from the first edge of said building panels, and which locking groove is open at the rear side of the building panels, the locking device comprising a strip integrated with the second edge of each of said building panels, said strip extending throughout substantially an entire length of the second edge and being provided with a locking element projecting from the strip, such that when two adjacent building panels are joined together, the strip projects from the rear side of the second edge of the panels with its locking element received in the locking groove of an adjacent building panel, the building panels, when joined together, can occupy a relative position in said second direction where a play exists between the locking groove and a locking surface on the locking element that is facing the first and second edges and is operative in said second mechanical connection, the first and the second mechanical connections both allow mutual displacement of the building panels in a direction of the first and second edges, and the second mechanical connection enables the locking element to leave the locking groove if the respective building panel is turned about its first edge angularly away from the strip.