Floor panels with edge connectors

1. A floor panel, for forming a floor covering,

said floor panel having a panel thickness in the range of 5 to 15 mm;

said floor panel further including an upper side, an underside, and comprising a core material selected from the group consisting of medium density fiberboard and high density fiberboard;

said floor panel at least at the side edges of two opposite sides being provided with coupling parts substantially in the form of a tongue and a groove, said groove including an innermost point and being bordered by an upper lip and a lower lip, said coupling parts enabling two of such panels to be coupled to each other, said side edges including upper side edges adjacent the panel upper side;

wherein said lower lip extends distally beyond said upper lip;

wherein said locking elements comprise a recess in said lower lip and a protrusion at the lower side of said tongue, said recess and said protrusion having contact surfaces defining locking surfaces, which, in coupled condition of two of such panels with the tongue of one panel received in the groove of another panel, cooperate with each other to prevent separation of the panels in directions perpendicular to the related side edges and parallel to the underside of the coupled floor panels,

wherein the locking surface at said recess is located in the portion of said lower lip which extends beyond said upper lip;

wherein said coupling parts and said locking elements are formed in one piece from said core material

said upper side edges, coupling parts and locking elements being configured such that said coupling of a pair of panels is achievable by a turning movement wherein one panel by its side edge is angled-in to the side edge of the other panel until a tongue of one panel is fully received in the groove of the other panel with the locking surfaces in contact with each other, with the lower side of the tongue engaging and sliding along the upper side of the lower lip before the tongue is received fully in the groove;

said locking surfaces contacting each other when a pair of the panels are coupled by placement of the tongue of one panel into the groove of the other panel with the upper side edges of the panels adjoining each other, to thereby secure the upper side edges of said coupled panels in adjoined relationship while preventing unintentional separation between the upper side edges which would produce undesired gaps between the upper side edges in a direction perpendicular to the related side edges and parallel to the underside of the coupled floor panels;

wherein said tongue at its lower side proximally of its front edge and distally of the protrusion is provided with a curved surface acting as a guiding surface that guides the sliding movement of the tongue along the upper side of the lower lip when the panels are turned into each other;

wherein, upon coupling of two of the panels by turning one panel into the other and with the tongue fully received in the groove and the upper side edges adjoining each other, a first chamber is defined between the distal end of the tongue and the innermost point of the groove; and

the tongue, groove and the locking elements having a configuration such that in coupled condition of a pair of panels with the upper side edges adjoining each other and the locking surfaces in contact with each other, a second chamber is provided between the distal end of the lower lip of one panel and a portion of the other panel from which the tongue extends which faces said distal end of the lower lip.

2. The floor panel of claim 1 , wherein said floor panel is a laminated floor panel comprising a resin impregnated imprinted decor layer.

3. The floor panel of claim 1 , wherein the difference in length by which the lower upper lip extends beyond the upper lip, measured in the plane of the floor panel, is smaller than the thickness of the floor panel.

4. The floor panel of claim 1 , wherein the upper side of the tongue and a lower side of the upper lip are provided with corresponding flat contact surfaces which extend substantially parallel to a plane defined by the floor panel, said contact surfaces engaging and cooperating with each other when a pair of panels are coupled.

5. The floor panel of claim 1 , wherein the floor panel comprises a monolithic core of said medium density fiberboard and high density fiberboard.