Patent CZ-304981-B6 (CZ)
Title: Floor system and floorboard for making the floor system
Inventor: PERVAN DARKO
IPC: E04F15/04
Filed: 2002-01-14
Abstract: In the present invention, there is disclosed a locking system for mechanical joining of floorboards (1, 1´) at a joint plane (VP), said floorboards (1, 1´) having a core (30), a front side (2, a rear side (34) and opposite joint edge portions (4a, 4b), of which one (4a, 4b) is formed as a tongue groove (36) which is defined by an upper lip (39) and a lower lip (40), and has a bottom end (48), and the other (4b) is formed as a tongue (38) with an upwardly directed portion (8) at its free outer end, the tongue groove (36), seen from the joint plane (VP), having the shape of an undercut groove (36) with an opening, an inner portion (35) and an inner locking surface (45), and at least parts of the lower lip (40) being formed integrally with the core (30) of the floorboard, and the tongue (38) having a locking surface (65) which is formed to co-act with the inner locking surface (45) in the tongue groove (36) of an adjoining floor board, when two such floorboards (1, 1´) are mechanically joined, so that their front sides (4a, 4b) are positioned in the same surface plane (HP) and meet at the joint plane (VP) directed perpendicular thereto, characterized in that at least the major part of the bottom end (48) of the tongue groove, seen parallel with the surface plane (HP), is positioned further away from the joint plane (VP) than is the outer end (69) of the tongue (38), that the inner locking surface (45) of the tongue groove (36) is formed on the upper lip (39) within the undercut portion (35) of the tongue groove for co-action with the corresponding locking surface (65) of the tongue (38), which locking surface is formed on the upwardly directed portion (8) of the tongue (38) to counteract pulling apart of two mechanically joined boards in a direction (D2) perpendicular to the joint plane (VP), that the lower lip (40) has a supporting surface (50) for co-action with a corresponding supporting surface (71) on the tongue (38) at a distance from the bottom end (36) of the undercut groove, said supporting surfaces being intended to co-act to counteract a relative displacement of two mechanically joined boards in a direction (D1) perpendicular to the surface plane (HP), that all parts of the portions of the lower lip (40) which are connected with the core, seen from the point (C) where the surface plane (HP) and the joint plane (VP) intersect, are located outside a plane (LP2) which is located further away from said point than a locking plane (LP1) which is parallel there with and which is tangent to the co-acting locking surfaces (45, 65) of the tongue groove (36) and the tongue (38) where said locking surfaces are most inclined relative to the surface plane (HP), and that the upper (39) and lower (40) lips and tongue (38) of the joint edge portions (4a, 4b) are designed to enable disconnection of two mechanically joined floorboards by upward pivoting of one floorboard relative to the other about a pivoting centre (C) close to a point of intersection between the surface plane (HP) and the joint plane (VP) for disconnection of the tongue (38) of one floorboard (1´) and the tongue groove (36) of the other floorboard (1). Such supporting surfaces are to be found at least in the bottom part of the tongue and on the lower lip of the tongue groove. In the upper part, the co-acting locking surfaces can serve as upper supporting surfaces, but the upper lip of the tongue groove and the tongue can advantageously also have separate upper supporting surfaces.