Patent ID: 6715253
Filing Date: 2004-04-06
Classification: E04F

Abstract:
A locking system for mechanical joining of floorboards having a core and opposite first and second joint edge portions, adjoining floorboards in the mechanically joined position having their first and second joint edge portions joined at a vertical joint plane, said locking system comprisinga) for vertical joining of the first joint edge portion of a first floorboard and the second joint edge portion of an adjoining second floorboard, mechanical cooperating means, and b) for horizontal joining of the first and second joint edge portions, mechanical cooperating means which comprise a locking groove formed in the underside of said second floorboard and extending parallel with and at a distance from the vertical joint plane at said second joint edge portion and having a downward directed opening, and a strip integrally formed with the core of said first floorboard, which strip at said first joint edge portion projects from said vertical joint plane and at a distance from the joint plane has a locking element which projects towards a plane containing an upper side of said first floorboard and which has at least one operative locking surface for coaction with said locking groove, the locking groove, seen in the plane of the floorboards and away from the vertical joint plane, having a greater width than said locking element, said at least one operative locking surface of the locking element is essentially planar and located at an upper part of the locking element at a distance from an upper side of the projecting strip and faces the joint plane, the locking groove has at least one essentially planar operative locking surface which is located in the locking groove at a distance from the opening of the locking groove and which is designed to cooperate with said locking surface of the locking element in the joined position, the locking groove at a lower edge closest to the joint plane has an inclined or rounded guiding part which extends from the locking surface of the locking groove and to the opening of the locking groove and which is adapted to guide the locking element into the locldng groove by engaging a portion of the locking element which is positioned above the locking surface of the locking element or adjacent to its upper edge, that said operative locking surfaces of the locking element and the locking groove make a locking angle of at least 50Â° to the upper side of the boards.