Abstract:
A process for installation of surface elements ( 1 ), the surface elements ( 1 ) comprising a core, a decorative upper surface ( 3 ) and edges ( 2 ) provided with joining means for mechanically locking the surface elements ( 1 ) together. Predetermined portions of the edges ( 2 ) are provided with a glue which is present on the edges ( 2 ) of the surface elements ( 1 ) in a passive dry form and which may be activated by applying a liquid. The surface elements ( 1 ) are joined to each other by use of the joining means wherein a unit of a plurality of surface elements ( 1 ) is formed.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional application of U.S. patent application Ser. No. 10/242,674, filed Sep. 13, 2002, now U.S. Pat. No. 7,332,053; which in turn is a continuation-in-part of U.S. patent application Ser. No. 09/988,014, filed Nov. 16, 2001 now abandoned, which in turn, is a continuation-in-part application of U.S. patent application Ser. No. 09/672,076, filed Sep. 29, 2000 now U.S. Pat. No. 6,591,568, claiming priority of Swedish Application No. 0001149-4, filed Mar. 31, 2000; the entire disclosures of which are incorporated hereby by reference in their entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to sealing of a joint comprising mechanical locking. 
     2. Description of the Prior Art 
     Prefabricated surface elements which at their edges are provided with groove and tenon are well known nowadays. As these are very easy to install it is possible for the normal handy man to achieve this. Such elements can be constituted of massive wood, fibre board or particle board. These are often provided with a surface layer, such as lacquer or some sort of laminate. The boards are most often installed by gluing them together via their groove and tenon. It is desired to join the separate elements so closely that the joint becomes practically invisible, which increases the moisture resistance radically. The usable life of the installed elements are thereby also increased. It is essential that glue is used excessively in order to achieve a tight joint. Any gaps will lead to moisture penetrating the joint with subsequent swelling of the core material closest to the joint. The glue also has to be used to an amount that it is spilled out through the joint on the decorative side of the surface elements. The superflous glue will of course have to be wiped off before beginning to set, which is rather time consuming. 
     One way of solving the problem is available on the market for some time now through different types of so-called click or snap-lock floor boards where no glue is to be used. The installation of such floor boards has become much swifter as no glue is required. The problems with these type of surface elements are that relativelly small spills of fluids like water may cause great damage on the installed surface elements as well as subwalls and especially subfloors as the fluid will run through the joints rather rapidly due to the capillary effect. It is, of course, possible to use glue on these snap-lock type of elements as well although the problem with the time consuming cleaning during installation would remain. 
     BRIEF SUMMARY OF THE INVENTION 
     It has, through the present invention, been made possible to solve the above mentioned problems so that self sealing surface elements can be achieved. Accordingly the invention relates to a process for installation of surface elements. The surface elements comprising a core, a decorative upper surface and edges are provided with joining means for mechanically locking the surface elements together. The invention is characterised in that predetermined portions of the edges are provided with a glue which is present on the edges of the surface elements in a passive dry form and which may be activated by applying a liquid. The surface elements are thereby joined to each other by use of the joining means wherein a unit of a plurality of surface elements is formed. The glue is suitably a polyvinyl alcohol [PVA] glue. The glue is suitably applied on the edges as an emulsion which then is allowed to dry before the joining of the surface elements. 
     The liquid used for reactivating the glue is suitably water. The water is advantageously mixed with alcohol since this reduces the surface tension of the liquid as well as increasing the evaporation rate. A thin coat of the liquid is suitably applied on the installed surface elements wherein small amounts of the liquid will pentetrate into the joints thereby moisturising and activating the glue. The glue will thereby expand and merge over the edges of the joint and will act as sealant against further penetration of liquid. It is not necessary to actively activate the glue by applying the liquid over the installed surface elements as small amounts of liquid accidently spilt on the installed surface elements will pentetrate into the joints thereby moisturising and activating the glue so that the glue expands and merges over the edges of the joint thereby acting as a sealant against further penetration of liquid. 
     According to one embodiment of the invention the joining means comprises lower joining lips at two adjacent edges while the two remaining edges are provided with upper joining lips. The lower joining lips are provided with intrinsically vertical lower lip surfaces arranged parallel to the closest edge. The lower lip surfaces are adapted to interact with mainly vertical upper lip surfaces arranged on the upper joining lips so that two joined adjacent surface elements are locked together in a horizontal direction. The joining lips are furthermore are provided with at least one heel adapted to snap join with recesses which, by being provided with intrinsically horizontal locking surfaces, limits vertical movement between two joined adjacent surface elements. The surface elements are hereby assembled by being pressed downwards once the edges are vertically aligned. 
     According to another embodiment of the invention the surface elements comprises a combination of at least two different types of surface elements, which types comprise female surface elements and male surface elements, whereby: 
     a) The female surface element is provided with a female joining member on at least half of the number of its edges and a male joining member on less than half of the number of its edges. 
     b) The male surface element is provided with a male joining member on at least two thirds of the number of its edges and a female joining member on less than one third of the number of its edges. 
     c) An optional joining profile possibly constitutes a junction between two adjacent male joining members of two adjacent surface elements. 
     The female joining member comprises an upwards protruding lip, being parallel to the edge, with a guiding surface. The guiding surface faces the edge. The female joining member also comprises a locking groove, being parallel to the edge. The locking groove has a locking surface facing downwards, which locking surface terminates in a locking edge. An angle αI between the guiding surface and vertical plane is in the range 0-30° while an angle βII between the locking surface and a horizontal plane also is in the range 0-30° as seen in a perpendicular cross-section. 
     The male joining member comprises a groove, being parallel to the edge, on the lower side with a guiding face. The guiding face faces away from the edge. The male joining member is also provided with a locking heel, being parallel to the edge The locking heel has a locking face facing upwards. An angle βI between the guiding face and a vertical plane is in the range 0-30° while an angle βII between the locking face and a horizontal plane is also in the range 0-30° as seen in a perpendicular cross-section. 
     The possible joining profile comprises two upwards protruding rims, being parallel to each other and distanced from each other by a centre section. The two upwards protruding rims are provided with guiding areas, the guiding areas facing inwards. The joining profile is furthermore provided with two locking cheeks placed on an extension. The locking cheeks has locking areas facing downwards, which locking areas terminates in a locking edge. An angle ΨI between the guiding area and a vertical plane is in the range 0-30° while an angle ΨII between the locking area and a horizontal plane is in the range 0-30° as seen in a perpendicular cross-section. The angles αI and βI are mainly the same, the angles αII and βII are mainly the same and the angles ΨI and ΨII are mainly the same. 
     According to yet another embodiment of the invention the surface elements are joined by means of joining members. The edges are separated into a first and a second edge, which first and second edges are arranged on opposite sides, and a third and a fourth edge being adjacent to the first and the second edge and which third and fourth edges are arranged on sides opposite to one another. The surface elements are provided with male joining members on the first edge while the second edge of the surface elements are provided with a female joining member. The male joining member is provided with a tongue and a lower side groove, while the female joining member is provided with a groove and a cheek, the cheek being provided with a lip. The surface elements are joined together via the male and female joining members by tilting the surface element to be joined with an already installed surface element or a row of already installed floor elements, with the male joining member of the surface element angled downwards. The first edge is positioned mainly parallel to the second edge of the already installed surface element or row of surface elements. The tongue of the tilted surface element is then inserted into the groove of the female joining member of the already installed surface element or row of floor elements, whereby the tilted surface element is turned downwards, with its lower edge as a pivot axis, so that the lip eventually snaps into the lower side groove where the decorative upper layer of the surface elements are mainly parallel. The third and fourth edges of the surface elements are joined by means of joining members selected from the group consisting of: 
     a) The third edge of the surface elements are provided with a male vertical assembly joining member while the fourth edge is provided with a female vertical assembly joining member. The fourth edge is arranged on a side opposite to the third edge. 
     b) The third edge of the surface elements are alternatively provided with a male vertical assembly joining member while the fourth edge also is provided with a male vertical assembly joining member. The fourth edge is arranged on a side opposite to the third edge. The adjacent male vertical assembly joining members are joined by means of a separate vertical assembly joining profile. 
     Two adjacent edges of a surface element are at the same time, and in the same turning motion, joined with a surface element adjacent to the first edge and a surface element adjacent to the third or fourth edge. 
     These embodiments of the invention include: 
     The joint between two joined floor elements suitably also comprises cavities. According to one embodiment of the invention a snapping hook is constituted by a separate spring part which is placed in the cavity. Alternatively an undercut is constituted by a separate spring part which is placed in a cavity. The spring part is suitably constituted by an extruded thermoplastic profile, a profile of thermosetting resin or an extruded metal profile. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Particular embodiments of the invention is described further in connection to enclosed drawings whereby; 
         FIG. 1  shows a part of a surface element  1  according to a first embodiment of the invention. 
         FIGS. 2   a - b  show a part of a surface element  1  according to a second embodiment of the invention. 
         FIGS. 3   a - f  show a part of a surface element  1  according to a third embodiment of the invention. 
         FIG. 4  shows the third and fourth edges of a surface element  1  according to the embodiment according to  FIG. 2   a.    
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows parts of a surface element  1 . The surface elements  1  are provided with edges  2 , a horizontal lower side  5 , and a horizontal upper decorative surface  3 . The surface elements  1  are at two adjacent edges  2  provided with lower joining lips  10  (only one shown) while the two remaining edges  2  are provided with upper joining lips  20  (only one shown). The lower joining lips  10  are provided with mainly vertical lower lip surfaces  11  arranged parallel to the closest edge  2 . The lower lip surfaces  11  are intended to interact with mainly vertical upper lip surfaces  21  arranged on the upper joining lips  20  so that two joined adjacent surface elements  1  are locked together in a vertical direction. The joining lips  10  and  20 , respectively, are furthermore provided with each one heel  31  with a matching recess  32 . A vertical movement between two joined adjacent surface elements  1  is limited since the recess  32  and heel  31  respectively are provided with essentially horizontal locking surfaces. The joining surfaces are also provided with fitting surfaces  3   I  in order to avoid unintended gaps in the joint. The geometry of the joining edges are only shown schematically and may, of course, be changed in many ways within the scope of the invention. 
       FIG. 2   a  shows, in cross-section, a first and a second edge  2   I  and  2   II  respectively, during assembly. The figure shows parts of surface elements  1  with a mainly rectangular shape. The surface elements  1  are provided with edges  2 , a lower side  5  and an upper decorative layer  3 . The surface elements  1  are intended to be joined by means of joining members  200 . The surface elements  1  are provided with male joining members  220  on a first edge  2   I  while a second edge  2   II  of the floor elements  1  are provided with a female joining member  210 . The second edge  2   u  is arranged on a side opposite to the first edge  2   I . The male joining member  220  is provided with a tongue  110  and a lower side  5  groove  12 . The female joining member  210  is provided with a groove  13  and a cheek  14 , the cheek  14  being provided with a lip  15 . The surface elements  1  are intended to mainly be joined together by tilting the surface elements  1  to be joined with an already installed surface elements  1  or a row of already installed surface elements  1 , with the male joining member  220  of the surface elements  1  angled downwards and that the first edge  2   I  is allowed to be mainly parallel to the second edge  2   II  of the already installed surface element  1  or elements  1 . The tongue  110  of the tilted surface element  1  is then inserted into the groove  13  of the female joining member  210  of the already installed surface element  1  or elements  1 , whereby the tilted surface element  1  is turned downwards, with its lower edge  2  as a pivot axis, so that the lip  15  eventually falls into the lower side  5  groove  12  where the decorative upper layer  3  of the surface elements  1  are mainly parallel. The lip  15  and lower side  5  groove  12  are further provided with a cam  16  and a cam groove  17  which provides a snap action locking during the turning motion. 
       FIG. 2   b  shows, in cross-section, a third and a fourth edge  2   III  and  2   IV  respectively, of a surface element  1  according to the invention. The surface elements  1  are provided with a male vertical assembly joining member  220   I  on a third edge  2   III  while a fourth edge  2   IV  is provided with a female vertical assembly joining member  210   II . The fourth edge  2   IV  is placed on a side opposite to the third edge  2   III . The male vertical assembly joining members  220   I  are provided with mainly vertical lower cheek surfaces  21  arranged parallel to the closest edge  2 . The lower cheek surfaces  21   I  are intended to interact with mainly vertical upper cheek surfaces  22   II  arranged on the female vertical assembly joining members  210   II  so that two joined adjacent surface elements  1  are locked against each other in a horizontal direction. The male vertical assembly joining members  220   II  are moreover provided with two snapping hooks  23   I  while the female vertical assembly joining members  210   II  are provided with matching under cuts  24   II , which by being provided with mainly horizontal locking surfaces limits the vertical movement between two joined adjacent surface elements  1 . 
     The joint between a third and a fourth edge  2   III  and  2   IV , respectively, of two joined surface elements  1  further comprises contact surfaces which are constituted by the mainly horizontal locking surfaces of the under cut  23   I  and hook  24   II , the mainly vertical upper cheek surfaces  22   II  lower cheek surfaces  21   I  as well as upper mating surfaces  25 . The joint between two joined surface elements  1  also comprises cavities  60 . 
     As shown in  FIG. 1 , glue  4  may be included on at least one edge of surface element  1  and activated as heretofore described. Also, as shown in  FIG. 4 , which is an enlarged view of the third and an opposite fourth edges  4   III  and  4   IV , respectively, of surface element  1 , a cavity  460  houses a spring part  402  placed in the cavity  460 . The spring  402  acts as a hook to engage undercut  424   II . As with the heretofore described embodiment of  FIG. 2   a , the surface elements  1  of  FIG. 4  have the same horizontal upper decorative surface  3 , a horizontal lower side  5 , and male vertical joining member  420   I  and female vertical joining member  410   I . When assembled, decorative surfaces  3 , having upper mating surfaces  25 , form a joint which is practically invisible. 
       FIGS. 3   a ,  3   b ,  3   c  and  3   d  are shown in exploded view and in cross-section. In an embodiment of joining members  1210  ( FIG. 3   a ) and  1220  ( FIG. 3   b ) respectively for surface elements  111   I ,  111   II  according to the invention, before the assembly the surface elements  111   I ,  111   II  which are assembled vertically, have a rectangular shape, as seen from above. The surface elements  111   I ,  111   II  are provided with edges  112 ,  112   I  which are provided with joining members  1210 ,  1220 . The surface elements  111   I ,  111   II  are further provided with a lower sides  115 ,  115   I  and decorative top surfaces  113 ,  113   I . The surface elements  111   I ,  111   II  comprise a combination of at least two types of surface elements, which types comprises female surface elements  1111   I  and male surface elements  111   II . 
     The female surface element  111   I  is provided with a female joining member  1210  on at least half of the number of its edges  112  and a male joining member  1220  on less than half of the number of its edges  112   I . The female joining member  1210  comprises an upwards protruding lip  1211 , being parallel to the edge  112 . The upwards protruding lip  1211  is provided with a guiding surface  1212 , the guiding surface  1212  facing the edge  112 , and a locking groove  1213 , being parallel to the edge  112 . The locking groove  1213  has a locking surface  1214  facing downwards, which locking surface  1214  terminates in a locking edge  1215 . An angle αI ( FIG. 3   b ) between the guiding surface  1212  and a vertical plane is 10°, while the angle αII ( FIG. 3   b ) between the locking surface  1214  and a horizontal plane is 15° as seen in a perpendicular cross-section. 
     The male surface element  111   II  is provided with a male joining member  1220  on at least two thirds of the number of its edges  1121  and a female joining member  1210  on less than one third of the number of its edges  112 . 
     The male joining member  1220  comprises a groove  1221 , with a guiding face  1222 , being parallel to the edge  112   I , on the lower side  115 . The guiding face  1222  is facing away from the edge  112   I . The male joining member  1220  is also provided with a locking heel  1223 , being parallel to the edge  112   I . The locking heel  1223  has a locking face  1224  facing upwards. An angle βI ( FIG. 3   c ) between the guiding face  1222  and vertical plane is 10°, while an angle βII between the locking face  1224  and a horizontal plane is 15° as seen in a perpendicular cross-section. 
     Accordingly, the angles αI and  131  are the same and the angles αII and βII are also the same. 
     An optional joining profile  50  (see  FIGS. 3   e  and  3   f ) may possibly constitute a junction between two adjacent male joining members  11220  of two adjacent surface elements  1111   I  and  1111   II . 
     The section placed between the edges  1112  and the grooves  1221  has a thickness which is less than the maximum surface element thickness by a recess  116  on the lower side  115  of the surface elements  1111 . The thickness of the surface elements  111  is normally between 5 and 15 mm whereby a suitable depth of the recess  6  is 1-5 mm. 
     The width of the locking face  1224  is depending on aspects like the thickness of the surface element  111 , the material used in the core, the dimensions of the part between the locking groove  1213  and the lower side  115  and the angles αI and βI chosen. The width of the locking face  1224  is typically less than 30% of the thickness of the surface element which normally is between 5 and 15 mm whereby the width is less than 4.5 mm for floors with 15 mm thickness and 2.1 mm for a common surface element with a thickness of 7 mm. It has, however shown to be fully sufficient with a width between 0.2 mm and 1 mm. 
       FIGS. 3   e  and  3   f  show, in cross-section, an embodiment of a joining profile  50  to a surface element  1111   I  and  1111   II  according to the invention. The joining profile  50  is intended to be used as a junction between two male joining members  11220  and  11220   I . The joining profile  50  comprises two upwards protruding rims  511 , being parallel to each other and distanced from each other by a centre section  506 . The two upwards protruding rims  511  are provided with guiding areas  512 . The guiding areas  512  are facing inwards. The joining profile  50  is furthermore provided with two locking cheeks  513  placed on an extension  507 . The locking cheeks  513  has locking areas  514  facing downwards, which locking areas  514  terminates in a locking edge  515 . An angle ΨI between the guiding area  512  and the vertical plane is 10° and the angle ΨII between the locking area  514  and a horizontal plane is 15° as seen in a perpendicular cross-section. 
     Accordingly, the angles αI, βI ( FIGS. 3   a - 3   d ) ΨI and are the same and the angles αII, βII ( FIGS. 3   a - 3   d ) ΨII are also the same. In other embodiments of the invention the joint between two joined floor elements suitable also comprise cavities. According to one embodiment of the invention, the snapping hook, is constituted by a separate spring part which is placed in the cavity. Alternatively an undercut is constituted by a separate spring part which is placed in a cavity. The spring part is suitably made of an extended thermoplastic profile, a profile of thermosetting resin or a metal profile. 
     The invention is not limited by the embodiments shown since these can varied in different ways within the scope of the invention.