Abstract:
A flooring includes rectangular floorboards with long sides and short sides, the floorboards being joined in a herringbone pattern, long side to long side and long side to short side, wherein the floorboards have a surface layer of laminate, and the long sides of the floorboards have pairs of opposing mechanical connectors which at least allow locking-together both horizontally and vertically by inward angling.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   The present application is a continuation of U.S. Ser. No. 11/380,578, filed Apr. 27, 2006, which is a continuation-in-part of U.S. Ser. No. 10/235,940, filed on Sep. 6, 2002, and U.S. Ser. No. 10/413,566, filed on Apr. 15, 2003, and claims the priority of SE 0103130-1, filed in Sweden on Sep. 20, 2001 and PCT International Application No. PCT/SE02/01731, filed on Sep. 20, 2002, and which designated the United States, and the present application also claims the benefit of U.S. Provisional Application No. 60/372,082, filed in the United States on Apr. 15, 2002. PCT International Application No. PCT/SE02/01731 and U.S. Provisional Application No. 60/372,082 were incorporated by reference into U.S. Ser. No. 10/413,566. U.S. Ser. No. 10/235,940; U.S. Ser. No. 10/413,566; SE 0103130-1; PCT/SE02/01731; and U.S. Provisional Application No. 60/372,082 are hereby incorporated herein by reference. 

   TECHNICAL FIELD 
   The invention relates generally to the technical field of locking systems for floorboards. The invention concerns on the one hand a locking system for floorboards which can be joined mechanically in different patterns and, on the other hand, floorboards provided with such a locking system and various methods of installation. The invention is particularly suited for use in mechanical locking systems integrated with the floorboard, for instance, of the types described and shown in WO94/26999, WO96/47834, WO96/27721, WO99/66151, WO99/66152, WO00/28171, SE0100100-7 and SE0100101-5 which are herewith incorporated by reference, but is also usable in other joint systems for joining of flooring. 
   More specifically, the invention relates above all to locking systems which enable laying of mainly floating floors in advanced patterns. 
   FIELD OF APPLICATION 
   The present invention is particularly suited for use in floating wooden floors and laminate floors, such as massive wooden floors, parquet floors, laminate floors with a surface layer of high pressure laminate or direct laminate. Parquet floors frequently consist of a surface layer of wood, a core and a balancing layer and are formed as rectangular floorboards intended to be joined along both long sides and short sides. Laminate floors are manufactured by a surface layer and a balancing layer being applied to a core material consisting of wood fibres such as HDF. This application can take place by gluing an already manufactured decorative layer of high pressure laminate. This decorative layer is made in a separate operation where a plurality of impregnated sheets of paper are pressed together under high pressure and at high temperature. The currently most common method for making laminate floors, however, is direct lamination which is based on a more modern principle where both manufacture of the decorative laminate layer and the attachment to the fibreboard take place in one and the same manufacturing step. Impregnated sheets of paper are applied directly to the board and pressed together under pressure and heat without any gluing. 
   The following description of prior-art technique, problems of known systems as well as the object and features of the invention will therefore as non-limiting examples be aimed mainly at this field of application. However, it should be emphasised that the invention can be used in optional floorboards which are intended to be joined in different patterns by means of a mechanical joint system. The invention may thus also be applicable to floors with a surface of plastic, linoleum, cork, lacquered wood fibre surface, synthetic fibres and the like. 
   BACKGROUND OF THE INVENTION 
   Traditional laminate and parquet floors are usually laid in a floating manner, i.e. without glue, on an existing subfloor which does not have to be quite smooth or plane. Any irregularities are eliminated by means of underlay material in the form of e.g. cardboard, cork or foam plastic which is laid between the floorboards and the subfloor. Floating floors of this kind are usually joined by means of glued tongue-and-groove joints, (i.e. joints with a tongue on one floorboard and a tongue groove on an adjoining floorboard) on long side and short side. In laying, the boards are joined horizontally, a projecting tongue along the joint edge of one board being inserted into a tongue groove along the joint edge of an adjoining board. The same method is used on long side as well as short side, and the boards are usually laid in parallel both long side against long side and short side against short side. 
   In addition to such traditional floors which are joined by means of glued tongue/tongue groove joints, floorboards have been developed in recent years, which do not require the use of glue but which are instead joined mechanically by means of so-called mechanical joint systems. These systems comprise locking means which lock the boards horizontally and vertically. The mechanical joint systems can be formed by machining the core of the board. Alternatively, parts of the locking system can be made of a separate material which is integrated with the floorboard, i.e. already joined with a floorboard in connection with the manufacture thereof at the factory. The floorboards are joined, i.e. interconnected or locked together, by various combinations of angling, snapping-in and insertion along the joint edge in the locked position. By interconnection is here meant that floorboards with connecting means are mechanically interconnected in one direction, for instance horizontally or vertically. By locking-together, however, is meant that the floorboards are locked both in the horizontal and in the vertical direction. 
   The principal advantages of floating floors with mechanical joint systems are that they can be laid quickly and easily by different combinations of inward angling and snapping-in. They can also easily be taken up again and be reused in some other place. 
   Known Techniques and Problems Thereof 
   All currently existing mechanical joint systems and also floors intended to be joined by gluing have vertical locking means which lock the floorboards across the surface plane of the boards. The vertical locking means consist of a tongue which enters a groove in an adjoining floorboard. The boards thus cannot be joined groove against groove or tongue against tongue. Also the horizontal locking system as a rule consists of a locking element on one side which cooperates with a locking groove on the other side. Thus the boards cannot be joined locking element against locking element or locking groove against locking groove. This means that the laying is in practice restricted to parallel rows. Using this technique, it is thus not possible to lay traditional parquet patterns where the boards are joined long side against short side in “herringbone pattern” or in different forms of diamond patterns. 
   Such advanced patterns have originally been laid by a large number of wood blocks of a suitable size and shape being glued to a subfloor, according to a desired pattern, possibly followed by grinding to obtain an even floor surface and finishing in the form of e.g. varnish or oil. The wood blocks according to this technique have no locking means whatever, since they are fixed by gluing to the subfloor. 
   Another known method of laying advanced patterns implies that the wood blocks are formed with a groove along all edges of the block. When the wood blocks are then laid, tongues are inserted into the grooves in the positions required. This results in a floor where the wood blocks are locked in the vertical direction relative to each other by the tongue engaging in tongue grooves of two adjoining wood blocks. Optionally this method is supplemented with gluing to lock the floor in the horizontal directions and to lock the floor in the vertical direction relative to the subfloor. 
   U.S. Pat. No. 1,787,027 (Wasleff) discloses another system for laying a herringbone parquet floor. The system comprises a plurality of wood blocks which are laid on a subfloor to form a herringbone parquet floor. Each wood block is provided with a set of tongues and tongue grooves which extend over parts of each edge of the wood block. When the wood blocks are laid in a herringbone pattern, tongues and tongue grooves will cooperate with each other so that the wood blocks are locked together mechanically in both the vertical and the horizontal direction. The tongues and tongue grooves that are shown in Wasleff, however, are of a classical type, i.e. they cannot be snapped or angled together, and the locking effect is achieved only when a plurality of wood blocks are laid together to form a floor. The system according to Wasleff consists of two types of wood blocks, which are mirror inverted relative to each other as regards the location of tongues and tongue grooves. The design of the locking system is such that a shank-end mill is necessary to form the tongue grooves shown. This is a drawback since machining using a shank-end mill is a relatively slow manufacturing operation. 
   U.S. Pat. No. 4,426,820 (Terbrack) discloses that floorboards can be joined long side against short side if the floor consists of two different floorboards which a joint system which can be laid merely by inward angling, which is not displaceable in the locked position and in which floorboards cannot be joined by snapping-in. Moreover  FIGS. 11 and 23  show floorboards which are mirror inverted relative to each other. This is, however, not discussed in detail in the description. Col. 5, lines 10-13, seems to contain an indication that it is possible to join short side and long side. However, it is not shown how a complete floor can be joined using such floorboards to form a pattern. Owing to the non-existence of displaceability in the joined position and snappability, it is not possible to create, using such floorboards as disclosed by Terbrack, a floor of the type at which the present invention aims. 
   U.S. Pat. No. 5,295,341 (Kajiwara) discloses snappable floorboards which have two different long sides. One part of the long side is formed with a groove part and another part with a tongue part. Nor are such floorboards displaceable in the locked position. The manufacture is complicated, and nor can they be used to provide the desired pattern. 
   “Boden Wand Decke”, Domotex, January 1997 shows a laminate floor where floorboards with different surfaces have been joined to form a floor having a simple pattern. It is also shown that floorboards have been joined long side against short side, but only in such a manner that all the short sides which are joined with a long side extend along a straight line. Consequently, this is an application of a prior-art system. 
   All known floors which are laid in a herringbone pattern usually have a surface of wood. It is not known that laminate floors can be laid in a herringbone pattern. Such a laminate floor has the same appearance as a real wooden floor but can be produced at a considerably lower cost and with better properties as regards durability and impact strength. 
   OBJECTS AND SUMMARY 
   An object of the present invention is to provide floorboards, joint systems, methods of installation, methods of production and a method of disassembly, which make it possible to provide a floor which consists of rectangular floorboards which are joined mechanically in advanced patterns long side against short side and which can be disassembled and reused. Another object is to provide such floors at a lower cost than is possible today by efficient manufacture and installation of floorboards in advanced patterns. A specific object of one embodiment is to provide such floors with a surface layer of high pressure laminate or direct laminate. The terms long side and short side are used to facilitate understanding. The boards can also be square or alternatingly square and rectangular, and optionally also exhibit different patterns or other decorative features in different directions. 
   According to a first aspect, the present invention comprises a system for making a flooring which comprises quadrangular floorboards which are mechanically lockable, in which system the individual floorboards along their four edge portions have pairs of opposing connecting means for locking together similar, adjoining floorboards both vertically and horizontally (D 1  and D 2  respectively), and wherein the connecting means of the floorboards are designed so as to allow locking-together in a first direction in the plane of the floorboard by at least snapping-in and locking-together in a second direction in the plane of the floorboard by inward angling and/or snapping-in. Moreover the system comprises two different types of floorboard A and B respectively, the connecting means of one type of floorboard A along one pair of opposite edge portions being arranged in a mirror-inverted manner relative to the corresponding connecting means along the same pair of opposite edge portions of the other type of floorboard B. 
   An advantage of the present invention is that floorboards can be laid long side against short side in advanced patterns and that joining can be made quickly and easily in all the laying alternatives that may be used when laying in all four directions from a centre. 
   The mirror-inverted joint systems need not be identical to allow joining. Surfaces that are not active in the vertical and horizontal locking means may, for instance, have a deviating shape. For example, the outer part of the tongue and the inner part of the groove may be varied. 
   According to a second aspect, the present invention comprises a system for making a flooring, which comprises quadrangular floorboards which are mechanically lockable, in which system the individual floorboards along their four edge portions have pairs of opposing connecting means for joining together similar, adjoining floorboards at least vertically, and wherein the pairs of opposing connecting means of the floorboards at least in a first direction in the plane of the floorboard are designed so as to allow locking-together both horizontally and vertically by inward angling and/or snapping-in. Moreover also this system comprises two different types of floorboard, the connecting means of one type of floorboard along one pair of opposite edge portions being arranged in a mirror-inverted manner relative to the corresponding connecting means along the same pair of opposite edge portions of the other type of floorboard. 
   According to a third aspect, the present invention comprises a flooring, which is formed by means of one of the systems described above. According to a fourth aspect, the present invention comprises a set of floorboards for making such a flooring. Such a set may be advantageous in terms of distribution since a customer, by buying such a set, can obtain a set of floorboards which are adjusted to each other. This is particularly advantageous if variations may appear in the manufacturing process as regards, for instance, the colour of the surface or the tolerances of the connecting means. 
   According to a fifth aspect, the present invention comprises fitting pieces, which have at least one oblique edge and which along their edge portions have connecting means for cooperation with adjoining floorboards. Such fitting pieces may constitute an important aid in installation of a floor with an advanced pattern, such as a herringbone pattern, by the possibility of quickly and efficiently laying floorboards at an angle other than 90° with each other. Since also the fitting pieces are provided with connecting means, a herringbone flooring can be obtained, where both the frame and the actual herringbone pattern are mechanically locked together so that the entire floor is held together mechanically. 
   According to a sixth aspect, the invention comprises a locking strip for interconnecting floorboards provided with identical locking means. This can be an aid, for instance, in the cases where a fitting piece is not available or if one chooses to form all fitting pieces with identical connecting means all the way round, for instance with a view to reducing the number of variants of fitting pieces. 
   According to a seventh aspect, the present invention comprises a method for rational production of floorboards which have a system as described above. 
   An advantage of identical and mirror-inverted joint systems according to the invention is that the floorboards can be produced rationally although they consist of two different types, for instance boards of type A and boards of type B which have identical but mirror-inverted joint systems on long side and short side compared with the boards of type A. All long sides of A and B boards can be machined, for instance, in a first machine. Then the A boards proceed to another machine where the short sides are machined. The boards that are to be provided with mirror-inverted joint systems, for instance the B boards, are however rotated through 180° in the same plane before machining of the short sides. Thus the two types of board A and B can be manufactured using the same machines and the same set of tools. 
   According to an eighth aspect, the present invention comprises four alternative or supplementary methods for laying a flooring using the system above. Quick and efficient laying of a floor according to the present invention can be carried out by means of one of these methods. 
   According to a ninth and a tenth aspect, the present invention comprises a gripping tool as well as a method for disassembly of a flooring as described above. 
   According to an eleventh aspect, the present invention comprises a system for making a flooring, which comprises rectangular floorboards, joined in a herringbone pattern, with a surface layer of high pressure laminate or direct laminate, in which system the individual floorboards along their long sides have pairs of opposing mechanical connecting means for locking together similar, adjoining floorboards in both the vertical and the horizontal direction (D 1  and D 2  respectively). In this embodiment, the short sides need not have any locking means at all on the short sides since the floorboards are narrow and the short sides are held together by the long sides. The short sides may, however, have vertical and/or horizontal mechanical locking means as described above, and joining of the floor can also partly be made by means of glue which is applied to short sides and/or long sides or under the floorboards. The mechanical locking means on the long sides guide the floorboards and facilitate laying significantly also in the cases where glue is used. 
   If the length of the long side is a multiple of the length of the short side, for instance 1, 2, 3, 4 etc. times the length of the short side, symmetrical patterns can be produced. If the joint system can also be joined by angling, very quick installation can be carried out by, for instance, the long sides being laid by inward angling and the short sides by snapping-in. 
   The joint systems on long sides and short sides may consist of different materials or the same material having different properties, for instance wood or veneer of different wood materials or fibre directions or wood-based board materials such as HDF, MDF or different types of fibreboard. Also aluminium can be used in the joint system. This may result in lower production costs and better function as regards inward angling, insertion along the joint edge, snapping-in and durability. 
   The invention will now be described in more detail with reference to the accompanying schematic drawings which by way of example illustrate currently preferred embodiments of the invention according to its different aspects. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIGS. 1   a - e  show prior-art joint systems. 
       FIGS. 2   a - e  show a known floorboard which can be laid by angling and snapping-in. 
       FIGS. 3   a - b  show laying in parallel rows according to prior-art technique. 
       FIGS. 4   a - b  show a floorboard with a mirror-inverted joint system according to the invention. 
       FIGS. 5   a - b  show laying of flooring according to the invention. 
       FIGS. 6   a - c  show a first installation method according to the present invention. 
       FIGS. 7   a - b  show a second installation method according to the present invention. 
       FIGS. 8   a - e  show a third installation method according to the present invention. 
       FIGS. 9   a - e  show fitting pieces for producing a herringbone pattern flooring according to the invention. 
       FIGS. 10   a - c  show different laying patterns according to the invention. 
       FIG. 11  illustrates schematically a production method for producing floorboards according to the invention. 
       FIGS. 12   a - d  show how floorboards can be detached from each other. 
       FIGS. 13   a - d  show how long sides can be joined with short sides according to the invention. 
       FIG. 14  shows an alternative embodiment of a short side. 
   

   DESCRIPTION OF PREFERRED EMBODIMENTS 
   In the following description, the two types of floorboards according to embodiments of the invention will be designated A and B respectively. This aims merely at illustrating the cooperation between two types of floorboard. Which type of board is designated A and B respectively is immaterial. 
     FIGS. 1   a - e  illustrate floorboards  1 ,  1 ′ with a surface  31 , a core  30  and a rear side  32 , whose joint edge portions are provided with prior-art mechanical joint systems. The vertical locking means comprise a groove  9  and a tongue  10 . The horizontal locking means comprise locking elements  8  which cooperate with locking grooves  12 . The joint systems according to  FIGS. 1   a  and  1   c  have on the rear side  32  a strip  6  which supports or is formed integrally with the locking element  8 . The locking systems according to  FIGS. 1   b, d  and  e  are distinguished by the locking element  8  and the locking groove  12  being formed in the groove/tongue. The locking systems according to  FIGS. 1   a - 1   c  can be joined by inward angling, insertion along the joint edge and snapping-in, whereas the locking systems according to  FIGS. 1   d  and  1   e  can only be joined by horizontal snapping-in. 
     FIGS. 2   a - e  show a known floorboard  1  with known mechanical joint systems which can be joined with another identical floorboard  1 ′ by angling, insertion along the joint edge ( FIG. 2   d ) or snapping-in ( FIG. 2   e ). Floorboards of this type can only be joined with the long side  4   a  against the long side  4   b  since it is not possible to join tongue  10  against tongue or groove  9  against groove. The same applies to the short sides  5   a  and  5   b.    
     FIGS. 3   a - b  show a known installation method and a known laying pattern. In  FIG. 3   a , the tongue side  10  on long side and short side is indicated with a thick line. The method which is used today in installation of wood and laminate flooring with mechanical connecting means is shown in  FIG. 3   b . Identical boards are laid in parallel rows with offset short sides. 
     FIGS. 4   a - 4   b  show two rectangular floorboards which are of a first type A and a second type B according to the invention and whose long sides  4   a  and  4   b  in this embodiment are of a length which is 3 times the length of the short sides  5   a ,  5   b . The floorboards have a first pair of vertical and horizontal locking means, also called connecting means, which cooperate with a second pair of vertical and horizontal locking means. The two types are in this embodiment identical except that the location of the locking means is mirror-inverted. The locking means  9 ,  10  allow joining of long side against short side when the first pair of locking means  9  is joined with the second pair of locking means. In this embodiment, joining can take place by both snapping-in and inward angling, but also insertion along the joint edge. Several variants may be used. The two types of floorboards need not be of the same format, and the locking means can also be of different shapes provided that, as stated above, they can be joined long side against short side. The connecting means can be made of the same material or different materials or be made of the same material but with different material properties. For example, the connecting means can be made of plastic or metal. They can also be made of the same material as the floorboard, but subjected to a property modifying treatment, such as impregnation or the like. 
     FIGS. 5   a - 5   b  show a floor according to the invention which consists of floorboards according to  FIGS. 4   a  and  4   b , which are joined in a herringbone pattern long side against short side. The laying sequence can be, for instance, the one shown in  FIG. 5 , where the boards are laid in the number series from 1 to 22. 
   The invention is applicable to floorboards of many different sizes. For example, the floorboards may be approximately the same size as the wood blocks in a traditionally patterned parquet floor. The width may vary, for instance, between 7 and 9 cm and the length between 40 and 80 cm. However, it is also possible to apply the invention to floorboards of the size that is today frequent on the market for parquet or laminate floors. Other sizes are also conceivable. It is also possible that boards of different types (for instance A and B) be given different sizes for creating different types of pattern. Moreover, different materials can be used in different floorboards in the same flooring. Suitable combinations are e.g. wood-laminate, laminate-linoleum and wood-linoleum. Floating floorboards can also be manufactured by a surface of artificial fibres, such as needle felt, being applied to, for instance, a wood fibre-based board such as HDF. Wooden and laminate floors may then also be combined with such an artificial fibre floor. These combinations of materials are particularly advantageous if the floorboards have preferably the same thickness and joint systems which enable joining of the different floorboards. Such combinations of materials allow manufacture of floors which consist of parts with different properties as regards sound, durability etc. Materials with great durability can be used, for example, in passages. Of course, these combination floors can also be joined in the traditional manner. 
     FIGS. 6-8  show different methods for installation of herringbone pattern floors using floorboards. LD designates in all Figures the direction of laying. 
     FIG. 6  shows a first installation method. In  FIG. 6   a , a first floorboard G 1  and a second floorboard G 2  are interconnected and possibly locked together long side against short side. The interconnection can here take place by either snapping-in, insertion along the joint edge or inward angling. Such inward angling takes place by rotation about an essentially horizontal axis. A third floorboard G 3  is added by first being connected and locked long side against long side with the floorboard G 2  and then in the locked state being displaced along the floorboard G 2  to be connected or locked with its short side against the floorboard G 1 . The connection with the floorboard G 2  can take place by inward angling or snapping-in while the connection with the floorboard G 1  takes place by snapping-in. 
     FIG. 6   b  shows an alternative way of adding the third floorboard G 3 , in which case the floorboard G 3  is first connected with its short side against the long side of the floorboard G 1  and then displaced in the locked state along the floorboard G 1  and connected or locked together by snapping together with the floorboard G 2 . The method according to  FIG. 6   a  and  FIG. 6   b  yields essentially the same result. 
     FIG. 6   c  shows how a further floorboard G 4  is added in the same way as the floorboard G 3  was added, i.e. either by the connecting sequence according to  FIG. 6   a  or the connecting sequence according to  FIG. 6   b . Further floorboards can then be added by repeating these steps. 
     FIG. 7   a  shows a second installation method. In  FIG. 7   a  two floorboards G 1  and G 2  are locked together or connected in the same way as in  FIG. 6   a  above. Then the floorboard G 3  is connected or locked together with the short side of the floorboard G 1  and the long side of the floorboard G 2 , these short sides and long sides forming a uniform joint edge with essentially identical connecting means. Thus, the floorboard G 3  can be connected and possibly locked together by either inward angling, insertion along the joint edge or snapping-in. The location of the floorboard G 3  can possibly be adjusted by displacement of the floorboard along the joint edge so that its short side is aligned with the long side of the floorboard G 1  and, together with this, forms a uniform joint edge.  FIG. 7   b  shows how the floorboard G 4  is joined with the common joint edge formed by the floorboards G 1  and G 3  in the same way as the floorboard G 3  was added. 
     FIG. 8  shows a third installation method. 
     FIG. 8   a  shows how a plurality of floorboards G 0 , G 1  and G 3  are arranged and joined long side against long side, the short sides of the floorboards being displaced relative to each other. The displacement of the short side is preferably the same as the width of the floorboard G 2 . The displacement can be performed, for instance, by using fitting pieces as will be shown in more detail in  FIG. 9 . The adding of the floorboard G 2  can be carried out in two ways. 
     FIG. 8   a  shows how the long side of the floorboard G 2  is first joined by inward angling, insertion or snapping-in with the short side of the floorboard G 1 . Then the floorboard G 2  is displaced in the connected state along the short side of the floorboard G 1  until the short side of the floorboard G 2  is connected with the long side of the floorboard G 3  by snapping-in. 
     FIG. 8   b  shows the second way of adding the floorboard G 2 , i.e. its short side is first connected with the long side of the floorboard G 3  by inward angling, insertion or snapping-in and then in the connected state displaced along the same until the long side of the floorboard G 2  is connected with the short side of the floorboard G 1  by snapping-in. 
     FIG. 8   c  shows how a further floorboard G 4  is added. First one long side of the floorboard G 4  is connected with the long side of the floorboard G 2 . Subsequently the floorboard G 4  is moved in between the floorboards G 2  and G 0  so that connection of the other long side of the floorboard G 4  and the short side of the floorboard G 0  takes place by a displacing motion, in which the connecting means of the floorboard G 4  are linearly displaced into the connecting means on the short side of the floorboard G 0 , for the connecting means on the short side of the floorboard G 4  to be connected with the long side of the floorboard G 1  by snapping-in. 
   The adding of further floorboards takes place by repeating the steps according to  FIG. 8   c.    
     FIGS. 8   d  and  8   e  show an alternative way of adding floorboards to an installed row of boards G 0 , G 1 , G 3 . 
   In  FIG. 8   d , the floorboard G 2  can be connected with the floorboard G 0  and G 1  either by the long side of the floorboard G 2  being first connected with the short side of the floorboard G 0  by inward angling, insertion or snapping-in and then being displaced in the connected state until its short side is connected with the long side of the floorboard G 1  by snapping-in, or by the short side of the floorboard G 2  first being connected with the long side of the floorboard G 1  by inward angling, insertion or snapping-in and then being displaced in the connected state along the same until its short side is connected with the long side of the floorboard G 1  by snapping-in. 
     FIG. 8   e  shows the adding of a further floorboard G 4 . It is preferred for the long side of this floorboard first to be connected by inward angling, snapping-in or insertion with the floorboards G 1  and G 4 , whose long side and short side respectively are aligned with each other and form a uniform continuous joint edge. Then the floorboard G 4  is displaced along this joint edge until the short side of the floorboard G 4  is joined with the long side of the floorboard G 3  by snapping-in. Alternatively, the reverse joining sequence may be used, i.e. first the short side of the floorboard G 4  is joined with the long side of the floorboard G 3  by inward angling, insertion or snapping-in, and then the floorboard G 4  is displaced in the connected state along the long side of the floorboard G 3  until the long side of the floorboard G 4  is connected with the short sides and long sides respectively of the floorboards G 1  and G 2 . 
   The installation methods described above can be combined if required by the current installation situation. As a rule, when two joint edges are interconnected or locked together, that part of the joint edge which is active in the interconnection or locking-together of the joint edges may constitute a larger or smaller part of the joint edge. Interconnection or locking-together of two floorboards can thus take place even if only a small part of the joint edge of the respective floorboard is active. 
     FIGS. 9   a - e  show different ways of terminating the floor along the walls. A simple method is just to cut the ends of the floorboards so that they obtain a shape that connects to the walls. After cutting, the cut-off edge may be covered with a baseboard in prior-art manner. 
   A second alternative may be to use a frame comprising one or more rows of floorboards which are laid along the walls and which may have a shape according to the numbered floorboards  1 - 13 . With such laying, all floorboards in the frame except the floorboard A 13  can be joined mechanically. The other floorboards can be cut off in conjunction with installation and be connected in a suitable manner using glue, or by making a tongue groove or tongue by means of, for instance, a hand-milling machine. Alternatively, a tongue groove and a loose tongue can be used as shown in  FIGS. 9   c  and  9   d.    
   A third alternative is that the frame  1 - 13  is filled with 10 different factory-made fitting pieces  14 - 23 , which are shown in  FIG. 9   b  and which have a mechanical joint system with a groove side  9  (indicated with a thin line) and a tongue side  10  (indicated with a thick line). The fitting pieces can be of different shapes, such as triangles or trapezoids, and preferably have an oblique side, which is cut to a suitable angle to fit the other floorboards. In a normal herringbone parquet floor this angle is preferably 45°. Also other patterns and angles than those shown in  FIG. 9  are feasible. According to one embodiment, the fitting pieces are provided with connecting means on all edge portions for cooperation with adjoining floorboards, as shown in  FIG. 9   b . It is also possible to make the fitting pieces by cutting the floorboards to a suitable shape and then providing them with connecting means, either on the site of installation by using a mobile set of tools, or by the fitting pieces after cutting being transferred to a factory or workshop for machining. 
   What is here said about designing of the connecting means on the floorboards is applicable in appropriate parts also to the fitting pieces. 
   If the fitting pieces are only provided with a groove  9  and if a loose tongue  10  is used as shown in  FIG. 9   c  for joining by means of glue or with a loose tongue  10  which also constitutes a mechanical joint system according to  FIG. 9   d , the number of fitting pieces in the assortment can be reduced significantly since these fitting pieces can then be mirror-inverted. In the preferred alternative, the number of fitting pieces can be reduced to four different fitting pieces marked in  FIG. 9  with  14 ,  15 ,  16  and  17 . A factory-made groove with a loose tongue may facilitate installation significantly since the vertical position of the groove in relation to the surface of the floorboards can be obtained with greater accuracy than is allowed when using, for instance, hand tools. The loose tongue  10  may consist of, for instance, an extruded section of plastic or aluminium. It can also be made by machining a suitable wood fibre based board, wood material or the like. 
   The loose tongue  10  shown in  FIG. 9   d  constitutes both a vertical and a horizontal locking means and thus enables mechanical joining of all sides of a board with other similar floorboards. The loose tongue  10  can be shaped in many different ways with one or more horizontal connecting means on both sides, and it can be designed for joining by snapping-in, insertion and/or inward angling. Variants of the tongue types  10  as shown in  FIGS. 1   b ,  1   d  and  1   e  as well as other known locking systems can be modified so that they may constitute two-sided loose tongue elements with locking elements  8  which lock floorboards whose joint edges are formed with suitable cooperating tongue grooves  9  with locking grooves  12  analogously to  FIG. 9   d.    
   Further a strip can be provided, which can be mounted on a cut-off edge of a floorboard and which is intended for cooperation, such as interconnection or locking-together, with locking means of adjoining floorboards. The strip can be made of a suitable material, such as wood, aluminium, plastic etc, and can be adapted to be fastened to a floorboard edge which, as a result of e.g. cutting off, does not have an integrated mechanical locking system. The strip is conveniently adjusted to the type of connecting means with which the other floorboards are provided, and it can be mounted with or without preceding milling. The strip can be provided by the meter to be cut off as required. Suitably the strip is fastened to the floorboard in a mechanical manner, such as by engagement in some kind of strip, recess or hole in the floorboard, but also glue, screws, nails, clips, adhesive tape or other fastening means are conceivable. 
   It is also possible to combine the embodiments so that both fitting pieces with factory-made connecting means on all edge portions and fitting pieces with other arrangements of connecting means are used in the same floor. For instance, the factory-made pieces can in such a case contribute to simplifying the fitting between the floorboards which constitute the frame and the floorboards which constitute the actual herringbone pattern. By means of this system, the frame can thus be laid along one or two walls, after which the herringbone pattern is connected to the frame by means of the fitting pieces, and the floor is laid starting from a first corner in the room. Adjustment for connection to the other walls can then take place using other types of connecting means or even in a conventional way, completely without connecting means. 
     FIGS. 10   a - c  show laying in a diamond pattern. Also in this embodiment, displacement in the locked position and snapping-in can be used for rational laying. 
     FIG. 10   a  shows a pattern in which floorboards of two types A, B can be laid. The numbering in  FIG. 10   a  represents a possible laying sequence. 
     FIG. 10   b  shows how floorboards of the two types A, B are joined short side against long side to form the pattern according to  FIG. 10   a.    
     FIG. 10   c  shows a method for facilitating laying of symmetrical patterns. The board A 4  is laid offset to facilitate laying of the other A boards aligned with the short sides of the B boards. Then the board A 4  may be pushed back to the correct position before continued laying, but it may also be centred between the A and B boards, and the diamonds can thus be laid in offset rows. The diamond pattern according to  FIG. 10  can advantageously be combined with wood blocks of other sizes to form, for instance, a so-called Dutch pattern. 
     FIG. 11  shows schematically a method for producing floorboards according to the present invention. Rational production of floorboards is essentially carried out in such manner that a set of tools and a floorboard blank are displaced relative to each other. The set of tools can advantageously be adapted to machine two opposite edge portions in one and the same displacing motion. This can be achieved by sets of tools  109  and  110  for making the respective locking means being arranged on each side of the path of movement F of the floorboard. A set of tools consists preferably of one or more milling tools which are dimensioned for quick machining of a profile in a manner known to those skilled in the art. In the example according to  FIG. 11 , use is a made of one set of tools  109  for machining the side where the groove  9  of the vertical locking means is formed and another set of tools  110  for machining the side where the tongue  10  of the vertical locking means is formed. 
   After a first machining step  109  which produces the locking means on one pair of opposite edges of the floorboard, a second machining step  105  is carried out, which produces the locking means on the other pair of opposite edges of the floorboard. This second machining step  105  takes place, just as the first, by displacement of the set of tools and the floorboard blank relative to each other but in a second direction which preferably is perpendicular to the first direction. The machining steps  101 ,  105  take place in a manner known to those skilled in the art and the order between them may be varied within the scope of the present invention. 
   As a rule, production of large amounts of floorboards is fully automated. The floorboard is thus moved automatically between the two production steps, which can be arranged so that the floorboard blank is first moved in a first direction F 1  in the longitudinal direction of the floorboard through a first machining device which comprises the first set of tools  109   a ,  110   a  and then in a direction F 2  which is essentially perpendicular to the first direction through a second machining device which comprises the second set of tools  109   b ,  110   b . The floorboards that are produced according to this method will all be of the same type, i.e. A or B according to the invention. 
   According to the invention, however, an existing production plant for production of floorboards of one type according to the invention can be adjusted for production of both types of floorboards using the same sets of tools. This takes place by a first type of floorboard (for instance A) being produced as described above, i.e. in two machining steps, while floorboard blanks which are to constitute a second type of floorboard (for instance B), after the first machining step  101  in step  104  is rotated half a turn in its plane. Subsequently the floorboard blank continues to the second machining step  105 . As a result, the position of one pair of connecting means on the floorboard B will be reversed, compared with the floorboard A. The floorboard B will thus be mirror-inverted in relation to the floorboard A. 
   Control of which boards are to be rotated can take place based on information from a control system  103  which controls a rotating device  102  which rotates the floorboard blank after the first machining step  101  before it is transferred to the second production step  105 . 
   When the floorboards A and B according to this preferred method are produced in the same line and with the same setting of tools, the two floorboards will have exactly the same length and width. This significantly facilitates symmetrical laying of patterns. 
   It is an advantage if the floorboards after installation can be taken up again and be relaid without the joint system being damaged. The take-up of a floorboard is conveniently made by a method which is essentially reversed compared with the installation method. One side, in most cases the short side, is released by the floorboard being pulled out horizontally so that the locking element  8  leaves the locking groove  12  by snapping-out. The other side, most conveniently the long side, can then be released by being pulled out along the joint edge, by upward angling or by snapping-out. 
     FIGS. 12   a - d  show various alternatives of releasing floorboards. In  FIG. 12   a , the floorboard  1 ′ has on the rear side  32  of the short side a gripping groove  120  which is adapted to a gripping tool  121  so that this gripping tool can engage in the gripping groove  121  with its gripping means  122 . This gripping means is connected with a means  123  which allows pressure or impact essentially in the horizontal direction K to be applied to the tool means outside the underside  32  of the floorboard and in this way release the board without it being damaged. The force can be applied by, for instance, impact (using e.g. a hammer or club, pulling or jerking at a handle or the like). The gripping tool can alternatively be designed so that its gripping means engages in another part of the floorboard, for instance the locking groove  12  or the locking element  8 , depending on the design of the joint system on the short side. Snapping-out can be facilitated by the locking element, for instance on the short side, being adjusted, for example by being made lower or with other radii etc. than on the long side, so that snapping-out and thus disconnection can take place at a lower tensile stress than, for example, for the long side. The joint system of the long side can consequently be designed, for instance, according to  FIG. 12   a  and the short side according to  FIG. 12   b  where the joint system has the same geometry except that the locking element  8  is lower.  FIG. 12   b  also shows that upper joint edges can be formed with beveled portions  131 ,  132  on long sides and/or short sides. If the floorboards are laid at an angle with long side against short side according to  FIG. 5   b , the long sides will prevent the short sides from separating especially if parallel displacement along the long sides is counteracted or prevented by means of e.g. high friction, glue, mechanical means etc. In such a laying pattern, short sides can be formed merely with vertical locking means according to  FIG. 12   c , or completely without locking means as in  FIG. 12   d . The gripping tool can be used to release also other types of mechanically joined floorboards which are laid in other patterns, such as parallel rows. It will be appreciated that a plurality of different combinations of embodiments of connecting means and installation methods are feasible to provide an optimal flooring as regards both installation method, durability and disassembly for reuse. 
     FIGS. 13   a - 13   d  show how long sides and short sides can be formed according to another embodiment. The long sides  4   a  and  4   b  in  FIG. 13   a  can be joined by inward angling. In the preferred embodiment, the floorboard consists of a material that does not allow sufficient bending down of the strip  6  so that horizontal snapping-in can be carried out.  FIG. 13   b  shows short sides  5   a  and  5   b  of the above floorboard. The locking element  8  has been made lower than on the long side and the locking surface of the locking groove has been made smaller. In this embodiment, the short sides cannot be locked in the horizontal direction.  FIGS. 13   c  and  13   d  show that the long side can be locked against the short side by both inward angling and snapping-in since the modified locking system on the short sides only requires a small bending down of the strip  6  when the floorboards are joined horizontally and snapped together. The long side  4   a  has in this embodiment a decorative groove  133  which only appears in one joint edge. The advantage is that the joint edge will be less visible than in the case when both joint edges of the boards  1 ,  1 ′ have decorative grooves. Moreover, manufacture will be simplified. 
   As illustrated in  FIG. 14 , in another alternative embodiment, the locking system on the short side, for instance, has no tongue. Therefore, the floorboards are lockable only in the horizontal direction. 
   The inventor has tested many different patterns which are all obvious, provided that floorboards of the same or different formats and with snappable and mirror-inverted joint systems are used in installation of flooring. Basically, the invention can be used to provide all the patterns that are known in connection with installation of parquet flooring with tongue and groove, but also parquet flooring which is laid by gluing or nailing to the base and which thus does not have a joint system which restricts the possibilities of joining optional sides. It is also possible to produce floorboards which have more than four sides and which can have a first pair of connecting means on 3, 4 or more sides and a second pair of connecting means on corresponding adjoining sides. Floorboards can also be made with more than two different pairs of cooperating locking means. It is possible to use all prior-art mechanical joint systems which can be snapped together. 
   Although the present invention has been described in connection with preferred embodiments thereof, it will be appreciated by those skilled in the art that additions, deletions, modifications, and substitutions not specifically described may be made without departing from the spirit and scope of the invention as defined in the appended claims.