Floor panels with edge connectors

1. A coupling system for joining panels, which panels are rectangular, including elongated or square, and which comprise a core, said core comprising a material selected from the group consisting of medium density fiberboard (MDF) and high density fiber board (HDF);

said panels comprising a decorative side, a back side opposite from the decorative side, a first pair of opposite side edges and a second pair of opposite side edges;

said coupling system comprising cooperating coupling parts provided at said first pair of opposite side edges enabling two of the panels to be coupled to each other without play;

wherein the coupling parts are substantially in the form of a tongue and a groove, said tongue and groove comprising an integral extension of said core material;

said groove closest to said decorative side being bordered by a first lip having a distal end and said groove closest to said back side being bordered by a second lip, said second lip also having a distal end, said second lip extending beyond said distal end of the first lip;

wherein the coupling parts are provided with integrated second lip and tongue mechanical locking elements which prevent unrestrained drifting apart of two coupled panels coupled without play in a direction perpendicular to the related side edges and parallel to a plane including the coupled panels;

said second lip and tongue locking elements defining contact surfaces, respectively at said second lip and said tongue, comprising second lip and tongue locking surfaces which in a coupled condition of two of such panels prevent said unrestrained drifting apart of the panels;

said second lip locking surface being located beyond the distal end of said first lip;

wherein said first lip is free of locking surfaces acting in the plane including two coupled panels;

wherein the coupling parts and locking elements enable two of such panels to be joined by means of a relative turning movement of one panel relative to the other panel along adjacent edges to be coupled;

wherein said coupling parts and locking elements are configured such that in the coupled condition of two of such panels without play, at least two intermediate spaces exist between the coupled side edges, including a first intermediate space and a second intermediate space;

said first intermediate space being located between the deepest point of the groove and the distal end of the tongue and extending at least partly between the second lip and the tongue; and

said second intermediate space being located between the distal end of the second lip of one of the coupled panels and a wall portion of the other of the coupled panels that is located in front of said distal end, said second intermediate space extending over an upper portion of the distal end of the second lip distally beyond and adjacent to said second lip locking surface.

2. The coupling system of claim 1 , wherein the length with which the second lip extends beyond the first lip, measured in the plane of the panel, is smaller than the thickness of the panel.

3. The coupling system of claim 1 , wherein said contact surfaces are configured so that a tangent line which is defined by said contact surfaces forms an angle with a plane of the coupled panels which is smaller than 90 degrees.

4. The coupling system of claim 1 , wherein said contact surfaces are planar.

5. The coupling system of claim 1 , wherein said second lip is provided with a recess, said recess being bordered distally by the locking portion of the second lip and wherein said groove, proximally from said recess, comprises a distinctly formed actual wall portion of the groove.

6. The coupling system of claim 1 , wherein the coupling parts and locking elements comprise cut profiles.

7. The coupling system of claim 1 , wherein said locking element at the tongue comprises a protrusion which cooperates with a recess in the second lip.