Mechanical locking system for floor panels

Technical field

The invention generally relates to the field of mechanical locking systems for building panels, building panels and production methods for inserting a tongue into a groove.

Field of application of the invention

The embodiments of the invention are particularly adapted for use in floating floors that are formed of floor panels that are mechanically connected by a locking system integrated with the floor panel mounted in e.g. the factory, they are made of one or more upper layers of wood or wood veneer, decorative laminate, powder-based surface or decorative plastic material, an intermediate core of wood-based material or plastic material, and preferably a lower balancing layer on the bottom side of the core. Floor panels with a surface layer of cork, linoleum, rubber or soft wear layers, e.g. felt glued to the board, printed surface, as well as preferably varnished and floors with hard surfaces such as stone, tile or similar materials are included.

Embodiments of the invention can also be used to connect building panels that preferably contain board material, for example wall panels, ceilings, furniture components and the like.

Therefore, in the following description of the state of the art, with reference to the above, all problems in known systems as well as the objects and features of the invention will be given in this field of application as a non-limiting example, and in particular with respect to panels formed as rectangular floor panels with long and short edges intended for for mechanical joining together with both long and short edges.

Long and short edges are mainly used to simplify the description of embodiments of the invention. The panels can be square. The invention is preferably used on short edges. It should be emphasized that the invention can be used in any floor panel and can be combined with all types of known locking systems formed on long edges in which the floor panels are intended to be joined by

EP 2 744 952 using a mechanical locking system connecting the panels in horizontal and vertical directions on at least two adjacent sides.

State of the art

The laminate floor element usually comprises a core of 6-12 mm fiber board, an upper layer of decorative laminate surface 0.2-0.8 mm thick and a lower leveling layer of laminate, plastic, paper or similar material 0.1-1 mm thick 0.6 mm. The laminated surface contains melamine impregnated paper. The most common core material is fiberboard with high density and good stability, usually called

HDF - High Density Fibreboard. Sometimes MDF - Medium Density Fibreboard (also called Medium Density Fiberboard) is used as the core.

Laminate floor elements are mechanically connected by so-called mechanical locking systems. These systems contain locking means that lock the panels horizontally and vertically. Mechanical locking systems are usually formed by machining the panel core. The parts of the locking system can be differently formed from a separate material, e.g. aluminum or HDF, which is integrated with the floor panel, e.g. connected to the floor panel in connection with its manufacture.

The main benefits of floating floats with mechanical locking systems are that they are easy to install. They can also be easily re-collected and used again in another place.

Definitions of certain terms

In the following description, the visible surface of the installed floor panel is called the "front side", while the opposite side of the floor panel, facing the floor, is called the "rear side". The edge between the front and back is called the "joint edge". "Horizontal plane" is understood to mean a plane which extends parallel to the part of the outer surface layer.

The upper parts of two adjacent edges of the connection of two connected floor panels, which are directly connected to each other, define a "vertical plane" perpendicular to the horizontal plane. "Vertical blocking" means blocking parallel to the vertical plane. "Horizontal blocking" means blocking parallel to the horizontal plane.

EP 2 744 952 "Up" means towards the front side, "down" means towards the rear side, "inward" means mainly horizontally towards the inside and center of the panel, and "outward" means mainly horizontally from the center of the panel.

"Locking systems" means cooperative connecting elements that connect floor panels vertically and / or horizontally.

The state of the art and its problems

Several methods can be used to mechanically join long edges as well as short edges in the vertical direction and the first horizontal perpendicular to the edge. One of the most commonly used methods is the angle snap method. Long edges are fitted by angling. The panel is then moved to a locked position along the long side. Short edges are locked by horizontal snapping. The vertical connection is generally a tongue and a groove. During horizontal displacement, the strip with the locking element is bent, and when the edges are tangent, the strip will spring back and the locking element will enter the locking groove and lock the panels horizontally. This snap connection is complicated because it may be necessary to use a hammer and knock block to overcome the friction between the long edges and to bend the belt during the snap action.

Similar locking systems can also be made with a rigid strip and are connected in an angled way - angled in which both the short and long edges are angled to the locked position.

Recently, new and very efficient locking systems have been introduced with a separate flexible and movable integrated tongue on the short edge, which allows assembly by only angling, generally described as "vertical folding". Such a system is described in WO 2006/043893 (Valinge Innovation AB).

Several versions are used on the market. One of the most commonly used versions is shown in Figs. 1a-1d. During locking, the flexible tongue 30 is displaced in the horizontally running displacement groove 40 and into the tongue groove 20 of the adjacent panel. The displaceable tongue locks the edges vertically, and the strip 6 with the locking element that cooperates with the locking groove 14 locks the panels horizontally. Blocking is a combination

EP 2 744 952 vertical displacement and rotation similar to the operation of scissors. The tongue moves gradually inward during blocking from one inner edge to the outer edge, as seen in Fig. 1d, so that the tongue is bent in the longitudinal direction. Such systems are described as vertical latch systems and provide automatic locking during folding operations.

Although these systems are very efficient, there is still room for improvement.

A high locking force can only be applied with high locking resistance when the tongue is pressed in and bent in the longitudinal direction. This creates separation forces that appear to push the panels away from each other when folded. Blocking can lose its strength if the flexibility and pressure of the tongue decrease over time.

The flexibility must be significant and allow the flexible tongue to be displaced in two directions by about 1-2 mm. The material that is used to make the tongues is rather expensive and glass fibers are generally used to strengthen the flexible tongue.

The main benefit would be that the latch will be eliminated in a system that locks automatically when folded.

WO 2013/017575 A1 discloses a connection of panel-type components through a lock that acts along adjacent side edges of the components and in which a connection can be made by lowering the component relative to the component which has already been assembled. The profiled slide is introduced in a movable manner on one of the components and a locking joint can be made with a locking recess on another component for vertical blocking. The profiled shoe has a locking tab with a first guide surface that is arranged obliquely relative to the mounting plane and which comes in contact with the locking surface of the locking recess during the lowering process so that the force of the component is applied to the profiled shoe which causes movement from the detachable position to the position interlocking.

The essence of the invention

The main purpose of an embodiment of the invention is to provide a locking system for mainly rectangular floor panels with edges

EP 2 744 952 long and short, mounted in parallel rows, which allows the short edges can be locked together automatically without snapping action, which creates blocking resistance and separation forces for the short edges during folding and that it contains means preventing tongue slipping back into the groove after locking.

The specific purpose is to provide a locking system with a separate displaceable tongue that can be bent in the longitudinal direction with a lower separation force. The above objectives of the embodiment of the invention can be achieved in whole or in part by locking systems and floor panels according to the application. Embodiments of the invention are obvious from the description and figures.

An aspect of the invention are building panels provided with a locking system for vertical blocking of the first and second building panels by vertical displacement of the panels with respect to each other. The displaceable tongue is inserted into the side-open displacement groove provided on the edge of the first panel. The tongue works with a tongue groove provided on the adjacent edge of the second panel to lock the edge vertically. The strip extends below the displacement groove and outward beyond the upper edge portion, or below the tongue groove and outwardly beyond the upper portion of the adjacent edge. The displaceable tongue includes a pulling extension on its outer portion adapted to mate with a pulling tab formed on the edge of the adjacent panel so that the displaceable tongue is pulled out of the displacement groove and into the tongue groove when the edges of the panels are moved vertically relative to each other.

The pulling tab may be part of the tongue groove.

The pulling extension can be tilted relative to the main horizontal plane of the panels.

The pulling tab can be tilted relative to the main horizontal plane of the panels.

The displaceable tongue is provided with a locking hook that prevents the tongue from sliding back into the displacement groove after locking.

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The locking hook may lock on the outside of the displacement groove.

Short description of the figures

The application will then be described in conjunction with the embodiments and in more detail with reference to the attached exemplary figures, where:

Figures 1a-d show locking systems according to known technology. Figs. 2a-e show the short edge locking system.

Figs. 3a-c show a short edge locking system according to non-claimed embodiments.

Figs. 4a-c show non-claimed embodiments of short edge locking systems with a separate strip.

Fig. 5a-e shows a locking system according to the invention with a locking hook that prevents unblocking.

Figs. 6a-d show the tongue according to an embodiment of the invention with increased flexibility relative to bending in the longitudinal direction.

Figs. 7a-d show a method according to an embodiment of the invention for inserting a tongue into a groove.

Figures 8a-c show an embodiment of the invention.

Description of preferred embodiments of the invention

To enable understanding, several locking systems are schematically illustrated in the figures. It should be emphasized that improved and various functions can be achieved using a combination of embodiments.

All embodiments can be used alone or in combinations. Angles, dimensions, rounded parts, spaces between surfaces etc. are only examples that can be adjusted within the basic principles of the invention.

In fig. 2a-2e shows a short edge locking system provided with a flexible and displaceable tongue 30 at the edge of the first panel 1, inserted into the horizontally running displacement groove 40. The movable tongue 30 has a pulling extension 31 comprising a tongue pulling surface 32 and a tongue blocking surface 33. The second adjacent panel 1 'has a pulling tab 21 with a pulling surface 22 of the groove, which is also part of the tongue groove 20 comprising the locking surface 23 of the groove.

EP 2 744 952

The pulling faces 22, 32 cooperate during vertical displacement and pull the movable tongue 30 into the tongue groove 20. The pulling extension 31 includes a tongue locking surface 33 that locks on the groove locking surface 23 and prevents vertical displacement of the edge in the first vertical direction. The locking strip 6 and bottom 39 of the adjacent panel locks the edges in a second vertical direction. The locking element 8 and the locking groove 14 lock the edges horizontally together with the upper edges. Vertical connection can be used without horizontal blocking, as seen in fig. 2e. Short edges can be locked horizontally by, for example, friction between long edges.

The tongue may be secured in the displacement groove 40 formed on the panel containing the strip 6, the panel strip or on the panel containing the locking groove, the panel groove as seen in Figs. 3a-3c. The pulling tab 21 may extend upwards or downwards, and the displacement groove may be inclined relative to the horizontal plane HP.

Figures 4a-4c show that the strip 6 can be formed as a separate material. The pulling tab 21 can be flexible and thereby eliminates manufacturing tolerances and allows tongue 30 to be displaced into the tongue groove 20 during folding.

In fig. 5a-5e, it is shown that the displaceable tongue 30 may include a locking hook 34 that can serve as a friction connection preventing the tongue 30 from falling out of the groove 40, but also preventing the tongue from slipping out of the blockage. The blocking angle A1 is preferably about 45 degrees or more. The higher angle allows displacement to the tongue groove 20, but also displacement backwards. This can be prevented by a hook connection 34 which preferably locks on the top or bottom of the displacement groove 40. The hook connection is pressed into the groove through a hammer that inserts the tongue 30 into the groove 40 during production. The hook 34 slides along the bevel formed in the displacement groove 40, as seen in Fig. 5c. The upper part of the blocking element 8 is preferably arranged vertically below the tongue blocking surface 33, as seen in Fig. 5d. This gives a stronger blockage. The locking system may have a geometry that allows locking and unlocking by angling.

EP 2 744 952

In fig. 6a-6c show how the displaceable tongue 30 rotates and bends in the longitudinal direction during folding when the inner short edge of the tongue as seen in Fig. 6b, is in the locked position and the outer short edge of the tongue 30 is in the unlocked position, as seen in Fig. 6d. The locking function can be improved if the depressions 35 are formed on the movable tongue 30. Locking can also be improved if the locking surface 32 on the edge has a lower edge than the inner part as seen in Fig. 6b and 6c.

The recesses 35 may be formed on the tongue section, where the locking hooks 34 are formed. The displaceable tongue 30 preferably contains polymer material and is preferably formed by injection molding.

Figs. 7a-7d show that the locking hook 34 can include a hook part 34a that is used to press the hook connection upwards by inserting rails 36 when inserting the tongue

thirty to the displacement groove 40.

In fig. 8a-8c show how the locking hook 34 can be used to prevent unblocking in any locking system where the tongue is moved in a groove from an inner position to an outer position. The illustrated locking system comprises push tabs 38 disposed in push cavities 37. The push tabs slide on the locking element 8 and push the tongue 30 into the tongue groove 20. The locking element 8 is preferably arranged vertically below the cooperating locking surfaces 23, 33 of the tongue 30 and the tongue groove 20.

EP 2 744 952