SE526596C2 - Floating floor with mechanical locking system that allows movement between the floorboards - Google Patents

Abstract

Floorboards with a mechanical locking system that allows movement between the floorboards when they are joined to form a floating floor.

Description

35 526 596 2 consisting of melamine-impregnated paper pressed together under pressure and heat. "Horizontal plane" means a plane parallel to the outer part of the surface layer. "Vertical plane" means a plane perpendicular to the horizontal plane.

The outer parts of the floorboard at the edge of the floorboard between the front and back are called the "joint edge". The "joint edge section" refers to a part of the joint edge of the floorboard.

"Joint" or "locking system" refers to cooperating coupling means that connect the floorboards vertically and/or horizontally. "Mechanical locking system" refers to the fact that the joining can be done without glue. Mechanical locking systems can also be joined with glue in many cases. "Vertical locking" refers to locking parallel to the vertical plane. Vertical locking is usually done with a tongue that interacts with a groove. "Horizontal locking" refers to locking parallel to the horizontal plane. "Joint opening" refers to a groove that is delimited by two joint edges of two joined floorboards and that is open to the floor surface. "Joint gap" refers to the minimum distance between two joint edge portions of two joined floorboards within an area that is limited by the floor surface and the upper part of the tongue closest to the floor surface. "Visible joint gap" refers to a joint gap that is visible to the naked eye from the front when a person walks on the floor.

Background of the invention Traditional laminate and parquet floors are usually laid floating on an existing subfloor. The joint edges of the floorboards are joined to form a floor surface and the entire floor surface can move in relation to the subfloor. As the floorboards shrink or swell in connection with the relative humidity RH varying during the year, the entire floor surface will change shape.

Floating floors of this type are usually joined by means of glued tongue and groove joints. When laying, the boards are joined together horizontally, whereby a protruding tongue along the joint edge of one board is inserted into a tongue groove along the joint edge of an adjacent board. The tongue and groove joint positions and locks the floorboards vertically and the glue locks the boards horizontally. The same method is used on both the long and short sides, and the boards are usually laid in parallel rows, long side to long side and short side to short side.

In addition to such traditional floating floors, which are joined together using glued tongue and groove joints, floorboards have been developed in recent years that do not require the use of glue but are instead joined mechanically using so-called mechanical locking systems. These systems contain locking elements that lock the boards mechanically horizontally and vertically without glue. The mechanical locking systems can be formed by machining the board core.

Alternatively, parts of the locking system can be formed from a separate material that is integrated with the floorboard, i.e. joined to the floorboard already in connection with its manufacture in the factory. The floorboards can be connected mechanically, through various combinations of angular movement, snapping, vertical position change and insertion along the joint edge.

Wood and laminate floors are also joined by gluing or nailing to the subfloor. This gluing/nailing counteracts moisture movement and keeps the floorboards joined together. The movement of the floorboards occurs around a center point in each floorboard. Swelling and shrinkage can occur by only changing the shape of each floorboard and thus not the entire floor surface.

Floorboards that are glued/nailed together do not need to have any locking systems at all. However, they may have traditional tongue and groove joints that facilitate vertical positioning. They may also have mechanical locking systems that lock and position the floorboards vertically and/or horizontally during installation.

Known technology and problems with this The advantage of floating floors is that shape changes due to different humidity RH can occur hidden under skirting boards and the floorboards can, despite swelling and shrinking, be joined together without visible joint gaps.

Installation can be done quickly and easily, especially with mechanical locking systems, and the floor can be taken up and relaid on another site. The disadvantage is that the continuous floor area must usually be limited even in cases where the floor consists of relatively dimensionally stable floorboards such as laminate flooring with a wood fiber core or wood flooring composed of several layers with different fiber directions.

The reason is that such dimensionally stable floors usually have a dimensional change of about 0.1%, corresponding to about 1 mm per meter, when RH varies between 25% in winter and 85% in summer. For example, such a floor will shrink and swell about 10 mm over a distance of ten meters. A large floor area must be divided into smaller areas with expansion strips, for example every ten or fifteen meters. If such a division does not take place, there is a risk that the floor will change shape during shrinkage so that it is no longer covered by skirting boards. The load on the locking system will also be large because large loads must be moved when a large interconnected surface moves.

The load becomes particularly great when passing through different room units.

Unstable floors such as homogeneous wooden floors can exhibit even greater deformation. The factors that primarily influence the deformation of homogeneous wooden floors are 10 15 20 25 30 526 596 5 grain direction and wood type. A homogeneous oak floor is very stable along the grain direction, i.e. in the longitudinal direction of the floorboard. In the width direction, the movement can be 3%, corresponding to 30 mm per meter or more, as the RH varies during the seasons. Other wood types exhibit even greater deformation. Floorboards that exhibit large deformation changes cannot generally be installed floating. Even if such an installation were possible, the continuous floor area would have to be significantly limited.

The advantage of gluing/nailing down is that large continuous floor areas can be created without expansion strips and the floor can have a large load. Another advantage is that the floorboards do not need to have any vertical and horizontal locking systems and they can then be installed in advanced patterns with, for example, long sides joined to short sides. However, this installation method with attachment to the subfloor has a number of significant disadvantages. The main disadvantage is that when the floorboards shrink, a visible joint gap occurs between the boards.

This joint gap can be relatively large, especially when the floorboards are made of moisture-sensitive wood materials.

Homogeneous wooden floors nailed to a subfloor may have joint gaps of 3 - 5 mm. The distance between the boards may be unevenly distributed with several small and a few large gaps and these gaps are not always parallel.

The joint gap can thus vary over the length of the floorboard.

The large joint gaps contain a lot of dirt that penetrates down towards the spring and prevents the floorboards from assuming their original position when swelling.

The installation methods are time-consuming and often the subfloor must be adapted to allow gluing/nailing. l0 15 20 25 30 526 596 6 It would therefore be a great advantage if it were possible to create a floating floor without the above-mentioned disadvantages, and especially a floating floor that: a) could consist of a large continuous surface without expansion strips, b) could consist of moisture-sensitive floorboards that exhibit large dimensional changes as the RH varies during the year.

Summary of the Invention The present invention relates to locking systems, floorboards and floors that enable floating floors to be installed in large continuous areas and with floorboards that exhibit large dimensional changes upon changes in relative humidity (RH).

A first object of the present invention is to provide a floating floor of rectangular floorboards with mechanical locking systems in which the floorboards' format, laying pattern and locking system interact and enable movement between the floorboards.

According to the invention, the individual floorboards can be deformed after installation, i.e. shrink and swell as a result of changes in the relative humidity. This can be done in such a way that the deformation of the entire floor surface can be reduced or preferably eliminated while the floorboards remain locked to each other without large visible joint gaps.

A second object is to provide locking systems that allow significant movement between floorboards without large and deep dirt-collecting joint gaps. Such locking systems are particularly suitable for moisture-sensitive materials such as wood but also when large floating floors are installed with wide and/or long floorboards. 10 15 20 25 30 526 596 7 The terms long side and short side are used in the description to facilitate understanding. According to the invention, the boards can also be square or alternating square and rectangular, and possibly also have different patterns and angles between opposing sides.

It should be particularly emphasized that the combinations of floorboards, locking systems and laying patterns that appear in this description are only examples of suitable embodiments. A variety of alternatives are possible.

All the embodiments that are suitable for the first purpose of the invention can be combined with the embodiments that describe the second purpose of the invention. All locking systems can be used separately in long sides and/or short sides and in various combinations on the long and short sides. The locking systems that have horizontal and vertical locking members can be joined by angling and/or snapping.

The geometries of the locking systems and the effective horizontal and vertical locking members can be designed by machining the edges of the floorboard or by forming separate materials or machining them before or after joining with the joint edge portion of the floorboard.

These purposes are achieved in whole or in part according to the following claims.

The present invention comprises a floating floor consisting of rectangular floorboards joined together by a mechanical locking system. The joined floorboards have a horizontal plane parallel to the floor surface and a vertical plane perpendicular to the horizontal plane.

The locking system has mechanically cooperating locking means for vertical joining parallel to the vertical plane and for horizontal joining parallel to the horizontal plane of a first and a second joint edge. The vertical locking means consist of a spring that cooperates 10 15 20 25 30 35 526 596 8 with a groove and the horizontal ones of a locking element with a locking surface that cooperates with a locking groove. The floor is characterized in that the format, installation pattern and locking system of the floorboards are designed such that a floor area of l * l meters can be deformed in at least one direction by at least 1 mm when the floorboards are pressed together or pulled apart with a force corresponding to 200 N per 100 mm joint length, whereby the deformation occurs without joint gaps exceeding approximately 0.1 mm. This deformation can occur without visible joint gaps.

In one embodiment of the locking system for mechanically joining floorboards to form a floating floor, the first and second joint edges have upper and lower joint edge portions located between the spring and the floor surface. The upper joint edge portions are closer to the floor surface than the lower ones. The locking system is characterized in that when the floorboards are joined and pressed together, the two upper joint edge portions are spaced apart and one of the upper joint edge portions in the first joint edge overlaps a lower joint edge portion in the second joint edge.

Brief description of the drawings Fig. 1a-b show floorboards.

Fig 2a¥2f shows locking system and laying pattern Fig 3a-3b shows locking system Fig 4a-4c shows locking system.

Fig 5a-5e shows joined floorboards, and a test method Fig 6a-6e shows locking system Fig 7a-7e shows locking system and a tool for forming a joint edge Fig 8a-8f shows locking system Fig 9a-9d shows locking system Description of embodiments 10 15 20 25 30 526 596 9 Figure la-b shows floorboards which are of a first type A and a second type B respectively and whose long sides 4a and 4b in this embodiment have a length that is 3 times the length of the short sides 5a, Sb. The long sides 4a, 4b of the floorboards have vertical and horizontal connecting means and the short sides 5a, 5b of the floorboards have horizontal connecting means. The two types are identical in this embodiment except that the location of the locking means is mirror-imaged. The locking means enable the joining of long side 4a to long side 4b by at least angling and long side 4a to short side 5a by angling and short side 5b to long side 4b by a vertical movement. Joining of both long sides 4a, 4b and short sides, 5a, 5b in a herringbone pattern or in parallel rows can in this embodiment be done by only an angular movement around the long sides 4a, 4b. The long sides 4a and 4b of the floorboards have connecting means which in this embodiment consist of a strip 6, groove 9 and tongue 10. The short sides Sa also have a strip 6 and groove groove 9 while the short sides 5b lack tongue 10. Several variants can occur. The two types of floorboards do not have to be of the same format and the locking means can also have different shapes provided that they can be joined long side to short side as described above. The coupling means may be formed of the same material or of different materials or may be formed of the same material but with different material properties. For example, the coupling means may be made of plastic or metal. They may also be made of the same material as the floorboard, but have been subjected to a property-modifying treatment, such as impregnation or the like. The short sides 5b may have a spring and the floorboards may then be joined together in a known manner in a checkerboard pattern by various combinations of angular movement and snapping movements 10 15 20 25 30 526 596 10 Fig. 2a shows the coupling means in two floorboards 1, 1' which are joined together. In this embodiment, the floorboards have a surface layer 31 of laminate, a core 30 of, for example, HDF, which is softer and more compressible than the surface layer 31, and a balance layer 32. The vertical locking D1 consists of a groove 9 that cooperates with a spring 10. The horizontal locking D2 consists of a strip 6, with a locking element 8 that cooperates with a locking groove 12. This locking system can be joined by angling around upper joint edges. The locking element 8 and the locking groove 12 have cooperating locking surfaces 15, 14. The floorboards can, when they are joined and pressed against each other in horizontal direction D2, assume a position where there is a play 20 between the locking surfaces 14, 15. When the floorboards are pulled apart from each other in the opposite direction, a joint gap 21 occurs between the upper joint edges. The play and gap may be, for example, 0.05 - 0.10 mm. Gaps of about 0.1 mm are considered acceptable. They are difficult to see and normal dirt particles are too large to penetrate the locking system through such small gaps.

Fig. 2b shows a common laminate floor 1.2 * with floorboards of 0.2 m format installed in parallel rows. Such a laminate floor shrinks and swells about 1 mm per meter. If the locking system has a clearance of about 0.1 mm, the five joints in the width direction D2 B will allow for a swelling and shrinkage of 5*0.1= 0.5 mm per meter. This only compensates for half the maximum swelling or shrinkage of 1 mm. In the longitudinal direction D2 A there is only one joint per 1.2 meters which allows for a movement of 0.1 mm. The clearance 20 and the joint gap 21 in the locking system thus contribute only marginally to reducing the shrinkage and swelling of the floor in the direction DZA parallel to the long sides. To reduce the movement of the floor to half the movement that normally occurs in floors without clearance 20 and joint gap 21, it is necessary to increase the clearance 20 to 0.6 mm and this results in an excessively large joint gap 21 on the short side.

Fig. 2c shows floorboards, with for example a core 30 of wood fibres such as HDF and surface layers of laminate or veneer, which have a maximum dimensional change of about 0.1% i.e. 1 mm per metre. The floorboards are installed in In this embodiment they are narrow and * 0.08 metres. If the gap is 0.1 mm, 12 floorboards with their parallel rows. short with a format which can for example be 0.5 12 joints over a floor length of one metre will enable a movement in the width direction D2 B of 1.2 mm, which is more than the maximum dimensional change of the floor. The entire movement can thus take place by the floorboards moving relative to each other and the outer dimensions of the floor can be unchanged. In the longitudinal direction D2 A the two short-side joints can only compensate for a movement of 0.2 mm per metre. In a room that is, for example, 10 meters wide and 40 meters long, an installation can conveniently be made with the long sides of the floorboards parallel to the width of the room and perpendicular to its length. According to this preferred embodiment, a large continuous floating floor surface without large visible joint gaps can thus be achieved with narrow floorboards that have a locking system with play and that are joined together in parallel rows perpendicular to the length of the floor surface. The locking system, the floorboards and the installation pattern according to the invention should thus be adapted so that a floor surface of 1 * 1 m can expand and compress about 1 mm or more in at least one direction without damaging the locking system or the floorboards. A mechanical locking system in a floating floor that is installed in a normal 10 15 20 25 30 526 596 12 home environment should have a mechanical locking system that can withstand a tensile load and compression corresponding to at least 200 kg per meter of floor length. More specifically, the above shape change without visible joint gaps should preferably be achieved when the floor surface above is subjected to a compressive or tensile load of 200 kg in any direction and when the floorboards are conditioned in normal relative humidity of approximately 45%.

Fig. 5d shows a suitable test method to ensure that the floorboards have sufficient movement capacity when joined. In this example, 9 test pieces with a length L of 100 mm (10% of 1 meter) have been joined with their respective long sides so that they correspond to a floor length TL of approximately 1 meter. The boards are subjected to tensile and compressive loads with a force F corresponding to 20 kg (200 N) which is 10% of 200 kg. The length change of the floor length TL must then amount to at least 1 mm. Fig. 5e shows how the corresponding test can be carried out in a floor installed in a herringbone pattern. The force F must then be adapted to the distance L between the short sides of the boards. If this distance is, for example, 0.6 meters, the force F must be 0.6 times 200 = 120 kg Fig. 2d shows floorboards according to Fig. 2c which are installed in a checkerboard pattern. This installation method provides 7 joints per running meter in both directions of the floor D2 A and D2 B. A gap of 0.14 mm can then completely eliminate swelling and shrinkage of 0.1%, since 7 joints provide a total movement opportunity of 7 *0.14 =1.0 mm.

Fig. 2e shows a m2 floor area consisting of the floorboards described above installed in a herringbone pattern long side to short side and shows the position of the floorboards when, for example, they have swollen to their maximum dimension in the summer. Fig. 2f shows the position of the floorboards when, for example, they have shrunk during the winter. The locking system with the 10 15 20 25 30 526 596 13 built-in play then provides a joint gap 21 between all joint edges of the floorboards. Since the floorboards are installed in a herringbone pattern, the play of the long sides will contribute to reducing the dimensional changes of the floor in all directions. Figure 2f also shows that the critical direction is the diagonal directions of the floor D2 C and D2 D where 7 joint gaps must be adapted so that they can handle a shrinkage over a distance of 1.4 meters. This can be used to determine the optimal laying direction in a large floor. In this example, a joint gap of 0.2 mm will completely eliminate movement of the floor in all directions. This allows the outer parts of a floating floor to be attached to the subfloor, for example by gluing down, which prevents the floor from moving outside the skirting boards during shrinkage.

The invention also enables partition walls to be attached to an installed floating floor, which can reduce installation time.

Practical tests show that floors with a surface of veneer or laminate and with a core of a wood fiber-based board, for example a dimensionally stable high-quality HDF, can be manufactured so that they are very dimensionally stable and with a maximum dimensional change in a normal home environment of about 0.5 - 1.0 mm per meter. Such floors can be installed in unlimitedly large spaces and the maximum play can be limited to about 0.1 mm even in cases where the floorboards have a width of preferably about 120 mm. Even smaller floorboards, for example 0.4 * 0.06 meters, are of course even more favorable and can handle large surfaces even when they are made of less dimensionally stable materials. The invention thus provides, according to a first embodiment, a new type of floating floor in which the individual floorboards have the possibility of movement and where the outer dimensions of the floor do not need to be changed. This can be achieved through optimal use of the format of the boards, the movement of the locking system using a small clearance and a small joint gap, and the installation pattern of the floorboards.

According to the invention, a suitable combination of clearance, joint gap, floorboard format, laying pattern and laying direction can thus be used to completely or partially eliminate movement in a floating floor. Much larger continuous floating floors can be installed than is possible today and the maximum movement of the floor can be reduced to the approximately 10 mm that applies to today's technology or completely eliminated. All this can be done with a joint gap that is practically not visible and that does not differ from floors that are joined with prestressing or a very small clearance that does not provide sufficient movement. As a non-limiting example, it can be mentioned that the clearance 20 and the joint gap 21 in dimensionally stable floors should suitably be approximately 0.1 -0.2 mm.

Fig. 3a shows a second embodiment that can be used to counteract the problems with moisture movements in floating floors. In this embodiment, the floorboard has a surface 31 of direct laminate and a core of HDF. Beneath the laminate surface is a layer 33 consisting of melamine impregnated wood fibers. This layer arises when the surface layer is laminated to HDF and when melamine penetrates into the core and joins the surface layer with the HDF core. The HDF core 30 is softer and more compressible than the laminate surface 31 and the melamine layer 33. According to one embodiment, the surface layer 31 of laminate and, where applicable, also parts or the entire melamine layer 33 under the surface layer can be removed so that a decorative groove 133 is formed in the form of a shallow joint opening JO 1. This joint opening imitates a large joint gap between homogeneous wooden floors. The groove 133 can be made 10 15 20 25 30 526 596 15 on only one joint edge and it can be colored, coated or impregnated in such a way that the joint gap becomes less visible. Such decorative grooves or joint openings can for example have a width JO l of for example 1-3 mm and a depth of 0.2-0.5 mm. When the floorboards 1, 1' are pressed together, the upper joint edges 16, can be compressed. This compression can in HDF be 0.1 mm. Such a compression possibility can replace the above-mentioned play and can enable movement without any joint gap.

A chemical treatment as above can also change the properties of the joint edge portion and contribute to improving the compression possibilities. Of course, the first and second embodiments can be combined. With a play of 0.1 mm and a compression possibility of 0.1 mm, a total movement of 0.2 mm can be achieved with a visible joint gap of only 0.1 mm. Compression can also be utilized between the active locking surfaces 15, 14 in the locking element 8 and in the locking groove 12. In normal climatic conditions, separation of the floorboards is prevented when the locking surfaces 14, 15 are in contact with each other and no significant compression occurs. In the event of additional tensile loading in extreme climatic conditions, for example when the RH drops below 25%, the locking surfaces are compressed. This compression is facilitated if the contact area CS of the locking surfaces 14, 15 is small. It is an advantage if this contact area in normal floor thicknesses of 8-15 mm is about 1 mm or less. With this technology, floorboards can be manufactured with a play and joint gap of about 0.1 mm. In extreme climatic conditions when RH is less than 25% and exceeds 80%, compression of the upper joint edges and locking surfaces can enable a movement of, for example, 0.3 mm. The above technology can be applied to many different types of floors, for example, floors with a surface of high-pressure laminate, wood, wood veneer and plastic and the like. The technology is particularly suitable in floorboards where it is possible to increase the compression of the upper joint edges by cutting off a part of the upper joint edge portion 16.

Fig. 3b shows a third embodiment. The floorboard 1' has, within an area of the joint edge which is limited by the upper parts of the tongue 10 and the groove 9 and the floor surface 31, an upper joint edge portion 18 and a lower joint edge portion 17 and the floorboard 1 has, in the corresponding area, an upper joint edge portion 19 and a lower joint edge portion 16. When the floorboards 1, 1' are pressed together, the lower joint edge portions 16, 17 come into contact with each other. The upper joint edge portions 18, 19 are spaced apart and the one upper joint edge portion 18 in one floorboard 1' overlaps the lower joint edge portion 16 in the other floorboard 1. In this compressed position, there is a play 20 of, for example, 0.2 mm between the locking surfaces 14, 15 in the locking system. If the overlap in this compressed position is 0.2 mm, the boards can separate from each other by 0.2 mm when pulled apart without any visible joint gap being visible from the surface. The decorative groove 133 can be made very shallow and any dirt that ends up in the groove can then be easily removed with a vacuum cleaner in connection with normal cleaning. No dirt or moisture can penetrate into the locking system and down towards the spring 12. This technique with overlapping joint edge portions can of course be combined with the two other embodiments. For example, the visible joint gap can be made 0.1 mm, the compression 0.1 mm and the overlap 0.1 mm. The movement of the floorboards will then be a total of 0.3 mm and this considerable movement can be combined with a small visible joint gap and a limited horizontal extension of the overlapping joint edge portion 18 which need not constitute any weakening of the joint edge. This is due to the fact that the overlapping joint edge portion 18 is partly very small and partly formed in the strongest part of the floorboard which consists of the laminate surface and melamine-impregnated wood fibers. Such a locking system which can thus provide a significant movement without visible joint gaps can be used in all the applications described above.

In addition, it is particularly suitable for use in wide floorboards, on the short sides, when the floorboards are installed in parallel rows and the like, i.e. in all applications that require a large amount of movement in the locking system to counteract dimensional changes in the floor.

It can also be used in the short sides of floorboards that form a frame FR or frieze around a floor installed in a herringbone pattern according to Fig. 5c. In this embodiment, the vertical extension of the overlapping joint edge portion, i.e. the depth of the joint opening GD, is less than 0.1 times the floor thickness T.

Fig. 4a and 4b show how a locking system can be designed to enable a floating installation of floorboards consisting of a moisture-sensitive material. In this embodiment, the floorboard consists of homogeneous wood.

Fig 4a shows the locking system in the tensioned position and Fig 4b shows the locking system in the compressed position. In order for the floor to have an attractive appearance, the relative size of the joint openings should not deviate too much from each other.

To ensure that the visible joint openings do not deviate too much during the movements of the floor, the smallest joint opening JO 2 should be larger than half the largest joint opening JO 1. Furthermore, the depth GD should preferably be less than 0.5*TT where TT is the distance between the floor surface and the upper parts of the tongue/groove. In the case where there is no tongue, GD should be less than 0.2 times the floor thickness T. This facilitates cleaning of the joint opening. It is also an advantage if JO 1 is approximately 1-5 mm, which corresponds to normal gaps in homogeneous wooden floors. According to one embodiment, the overlapping joint edge portion should preferably lie close to the floor surface. This enables a shallow joint opening at the same time as the vertical reading can be done with a tongue 10 and groove 9 which are placed essentially in the middle parts of the floorboard between the front and back sides where the core 30 has good stability. An alternative way of achieving a shallow joint opening that allows movement is shown in Fig. 4c. The upper part of the spring 10 has been moved up towards the floor surface. The disadvantage of this solution is that the upper joint edge portion 18 above the spring 10 becomes too weak.

The joint edge portion 18 can easily crack or deform.

Fig. 5a and Sb show the long side joint of three floorboards 1, 1' and 1" with the width W. Fig. 5a shows the floorboards when RH is low and Fig. 5b shows when RH is high. To imitate homogeneous floors, wide floorboards should preferably have wider joint gaps than narrower ones. JO2 should preferably be at least about 1% of the floor width W. 100 mm wide floorboards will then have a minimum joint opening of at least 1 mm. Corresponding joint openings in, for example, 200 mm wide planks should be at least 2 mm. Other combinations can of course also be used, especially in wooden floors where different types of wood and different climatic conditions impose special requirements.

Fig. 6a shows a wooden floor consisting of several layers of wood. The floorboard may, for example, consist of an upper layer of noble wood, for example oak, which constitutes the decorative surface layer 31. The core 30 may, for example, consist of plywood made of other types of wood or of a corresponding type of wood but of a different quality. Alternatively, the core may consist of wooden slats. The upper layer 31 generally has a different grain direction than a lower layer. In this embodiment, the overlapping joint edges 18 and 19 have been formed in the upper layer. The advantage is that the visible joint opening JO 1 will consist of the same type of wood and grain direction as the surface layer 31 and the appearance will be identical to a homogeneous wooden floor.

Fig. 6b and 6c show an embodiment where there is a small clearance 22 between the overlapping joint edge portions 16, 18 which facilitates horizontal movement in the locking system. Fig. 6c shows joining with an angular movement and with the upper joint edge portions 18, 19 in contact with each other.

The clearance 20 between the locking surface 15 of the locking element 8 and the locking groove 12 significantly facilitates joining by angle, especially in wooden floors that are not always straight.

In the above preferred embodiments, the overlapping joint portion 18 is formed on the tongue side, i.e. on the joint edge that has a tongue 10. This overlapping joint portion 18 can also be formed on the groove side, i.e. on the joint edge that has a groove 9. Figs 6d and 6e show such an embodiment. In Fig. 6d, the sheets are compressed in their inner position and in Fig. 6e, they are extended to their outermost position.

Fig. 7a-7b show that it is an advantage if the upper joint edge 18 which overlaps the lower 16 is on the tongue side 4a. The groove side 4b can then be joined by a vertical movement with a side 4a which lacks a tongue according to Fig. 7b. Such a locking system is particularly suitable on the short side. Fig. 7c shows such a locking system in the joined and compressed position. Fig. 7d and 7e show how the horizontal locking members, for example in the form of a strip 6 and a locking element 8 as well as an upper and lower joint portion 19, 16, can be formed with only one tool TO which has a horizontally working tool axis HT and which can thus form the entire joint edge. Such a tool can, for example, be mounted on a circular saw and with the help of a guide rail a high-quality joint system can be formed.

The tool can also saw off the floorboard 1. In the preferred embodiment, only a partial division of the floorboard 1 occurs at the outer portion 24 of the strip 6. The final division occurs by breaking off the floorboard. This reduces the risk of the tool TO being damaged by coming into contact with a subfloor of, for example, concrete.

This technique can be used to produce a frame or frieze FR in a floor that is, for example, installed in a herringbone pattern according to Fig. 5c. The tool can also be used to produce a traditional type of locking system without overlapping joint edge portions. Fig. 8a-8f show different embodiments. Fig. 8a-8c show how the invention can be used in locking systems where the horizontal reading consists of a spring 10 with a locking element 8 that cooperates with a locking groove 12 formed in a groove 9 that is limited by an upper 23 lip and where the locking groove 12 is in the upper lip 23. The groove also has a lower lip 24 that can be removed to enable joining with vertical movement. Fig. 8d shows a locking system with a separate strip 6 that is, for example, formed from an aluminum sheet. Fig. 8e shows a locking system that has a separate strip 6 that can be formed in a wood fiber-based material or in plastic, metal and the like.

Fig. 8f shows a locking system that can be joined by horizontal snapping. The spring 10 has a groove 9' which enables its upper and lower part with the locking elements 8, 8' to bend towards each other in connection with a horizontal displacement of the joint edges 4a and 4b towards each other. In this embodiment, the upper and lower lips 23, 24 in the groove 9 do not need to be resilient. The invention can of course also be used in conventional snapping systems where the lips 23, 24 can be resilient.

Fig. 9a-9d show alternative embodiments of the invention. When the boards are pulled apart, separation of the cooperating locking surfaces 14 and 15 is prevented. When the boards are pressed together, several alternative parts of the locking system can be used to define the inner position. In Fig. 9a, the inner position is determined by the outer part of the locking element 8 and the locking groove 10. According to Fig. 9b, the outer part of the tongue 10 and the groove 9 cooperate. According to Fig. 9c, the lower and front part of the tongue 10 cooperates with the groove 9. According to Fig. 9d, a locking element 10' on the lower part of the tongue 10 cooperates with a locking element 9' on the strip 6. It is obvious that several other parts of the locking system can be used according to these principles to define the inner position of the floorboards.

Claims (10)

10 15 20 25 30 526 596 22 PATENT REQUIREMENTS Floating floor consisting of rectangular floorboards (1, 1 ') joined by a mechanical locking system, in which floor the joined floorboards have a horizontal plane (HP) parallel to a floor surface (31) and a vertical plane (VP) perpendicular to the horizontal plane (HP), which locking system has mechanically cooperating locking means for vertical joining of the floorboards a first (VP) and for horizontal joining of the floorboards in a second direction (D1) parallel to the vertical plane direction (D2) parallel with the horizontal plane (HP) of the floorboards and perpendicular to a first and a second joint edge (4a and 4b respectively), and in which locking system the vertical locking means consist of a spring (10) cooperating with a groove (9) and the horizontal of a locking element ( 8) having a first locking surface (15), which cooperates with a locking groove (12) as (14), the floorboards having joint edge portions (17, 18; having a second locking surface 16, 19), which are located above said vertical locking means, characterized in that the format and locking system of the floorboards are designed so that a floor area of 1 * 1 meter is deformable in at least one direction, at least 1 mm when the floorboards are compressed or pulled apart with a force corresponding to 200 N per 100 mm joint length, whereby the deformation occurs without joint cracks exceeding approx. 0.1 mm. 10 15 20 25 30 35 526 596 23 Floating floor according to claim 1, characterized in that the width of the floorboards does not exceed about 120 mm. Floating floor according to claim 1 or 2, characterized in that there is a play between the locking surface (15) and the locking groove (12) of at least about 0.05 mm when the boards are pressed together Floating floors according to claims 1 - 3, characterized in that the floorboards are joined long side to short side. Floating floor according to claim 1 or 4, characterized in that the floorboards have a surface layer (31) of laminate and that parts of the surface layer (31) on at least one joint edge are felled. Floating floors according to any one of the preceding claims, 1 ') are designed such that said joint edge portions comprise upper (18, (16, 17) above said vertical locking means and the floor surface (31), the floorboards (1, 19) and lower joint edge portions , all of which are located, the upper joint edge portions (18, 19) being closer to the floor surface (31) than the lower joint edge portions (16, 17), wherein, when the floorboards are pressed against each other in (D2), the two lower joint edge portions (16, said horizontal direction 17) abut each other, the two upper joint edge portions (18, 19) are spaced apart, and one of the upper joint edge portions (18) of a first joint edge (4a) projects above and overlaps a lower joint edge portion ( 16) at a second, adjacent joint edge (4b) 10 15 20 25. (526 596 24 Floating floor according to claim 6, wherein the upper overlapping joint edge portion (18) has a lower limitation whose distance to the floor surface (31) is less than its distance to the upper part of the spring (10). Floating floor according to claim 7, wherein a minimum width (JO 2) of the joint gap is greater than half of a maximum width (JO 1) of the joint gap. Floating floor according to claim 8, wherein the surface layer (31) is made of wood and that the upper overlapping joint edge portion (18) is formed in its entirety by the surface layer. A floating floor according to claim 7, wherein the floorboards have a surface layer (31) of laminate and a core (30) of a wood fiber-based material, the upper joint edge portion (18) being formed in said surface layer and in the upper portions of the core closest to the surface layer, the vertical extent (DG) of the overlapping portion is less than 0.1 times the floor thickness (T).