Abstract:
A snowboard formed by a sandwich structure having a core formed by separate first and second parts that extend in the longitudinal direction of the board; the board having a central element that is positioned between the first part and the second part of the core and is formed by two independent components; wherein the independent components are secured together in a non-permanent manner by a connecting system that holds and positions the two independent components in a reversible manner, the connecting system sealing the connection against the ingress of resin during the manufacture of the board.

Description:
TECHNICAL DOMAIN 
       [0001]    The domain of the invention is devices for the practice of sliding sports on snow and more particularly for snowboards that can be separated into two parts and that can be used in a manner similar to nordic skis for climbing using the two separate parts. Such boards are usually better known as splitboards. 
         [0002]    This invention is more particularly related to a snowboard used for the practice of sliding sports on snow and a method of transforming such a board into a splitboard adapted for use either as a classical snowboard or as cross country skis by separation of the board into two distinct sliding parts. 
       STATE OF THE ART 
       [0003]    In the field of off-trail sliding sports, some snowboard practitioners would like to separate their board into two parts so that they can use it to help climb, particularly for the practice of nordic skiing. This practice combines the advantages of nordic skiing when climbing and the advantages of snowboard when descending, without having to carry additional equipment on the back. 
         [0004]    These practitioners can find snowboards precut in the factory into two distinct sliding parts that can be used separately for the practice of nordic skiing during climbing phases, or joined together during descent phases, on the market. To achieve this, the two sliding parts are joined and held together by hooks and other attachment systems, so as to reform a board for the practice of snowboarding. However, such boards precut into two parts in the factory have lower performances on trails than “standard” boards (i.e. single-piece boards). Furthermore, these boards precut in the factory are more expensive to buy than snowboards with a conventional design. 
         [0005]    Another less expensive solution for users who would like to purchase such a board is to make this type of splitboard themselves using their own means to cut a standard snowboard. Transformation kits are available to facilitate this manual DIY (Do It Yourself) practice, providing all the elements necessary to make a splitboard from a standard snowboard. However, this second alternative requires a large number of tools (metal saw, drill, circular saw, clamp; etc.), good manual and technical skills for cutting with a circular saw and also for drilling for hooks and other necessary attachment systems, additions of resin or plastic, sanding, etc. Thus, no less than about thirty successive operations are necessary to cut and transform a standard snowboard into a splitboard. Although this second solution is attractive on paper for practitioners, it is difficult for a single person to implement it and the transformation is often abandoned due to lack of time or because it is not really satisfactory because the user lacks technical and/or manual skills. 
       General Description of the Invention 
       [0006]    In this context, the invention is aimed at providing a board for the practice of sliding on snow and a transformation method to solve the above-mentioned problems. The board according to the invention has the advantage that it simplifies the work required by a private person to transform a standard snowboard (not precut in the factory) into a splitboard that can be used for the combined practice of nordic skiing and snowboarding. 
         [0007]    To achieve this, the invention aims to protect a board for the practice of sliding on snow composed of a sandwich structure comprising a core formed by distinct first and second parts extending along the longitudinal direction of said board; said board having a central element located between the first part and the second part of said core, formed by two independent parts; said board being characterised in that said independent parts are fixed together non-permanently by connection means reversibly holding the two independent parts together and positioning them, said connection means being designed to assure that the connection is sealed against the ingress of resin during manufacturing of said board. 
         [0008]    Thus, the snowboard disclosed by the invention is a standard construction snowboard with the special feature that it comprises a core separated into two distinct parts (i.e. not fixed together) so as to facilitate a transformation into a splitboard. 
         [0009]    The board according to the invention can also have one or several of the characteristics described below, either individually or in any technically possible combination:
       said central element is positioned on the median plane of said board;   said central element is made from a polymer material or a composite material;   each of the independent parts of said central element is fixed to a part forming the core;   the reversible connection means are formed from an adhesive layer designed to temporarily and reversibly hold the two parts together;   the reversible connection means are made by magnetisation of the two parts of the central element;   the two parts of the central element are made from a magnetic powder or a permanent magnet and a thermoplastic or thermosetting binder;   the two parts of the central element are separated by an anti-polymerisation layer designed to prevent permanent adhesion of the two parts during manufacturing of said board.       
 
         [0017]    Another purpose of the invention is a method of transformation of said board according to one of the previous claims into a board divided into two parts for the combined practice of nordic skiing and snowboarding, said board having a sandwich structure formed by a core composed of two distinct parts, lower and upper skins on each side of said core along the direction of the thickness, a bottom surface and an upper outer layer, said transformation method including steps to:
       cut the upper outer layer on the median plane of the board;   cut the upper skin;   cut the bottom surface;   cut the lower skin;   separate the two parts forming the core by separation of the connection means.       
 
         [0023]    The transformation method according to the invention can also have one or several of the characteristics described below, either individually or in any technically possible combination:
       the cutting steps are made using a cutting tool, for example a sharp tool such as a cutter or a knife;   the step to separate the two parts forming the core consists of a single step to break the layer separating the two parts forming the central element;   the method comprises a step to assemble the attachment means so that it is possible to reversibly attach and detach the two cut parts of said board.       
 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0027]    Other characteristics and advantages of the invention will become clearer after reading the description given below for guidance and that is in no way limitative, with reference to the appended figures among which: 
           [0028]      FIG. 1  shows a cross-sectional view of a first embodiment of a snowboard according to the invention; 
           [0029]      FIG. 2  shows a cross-sectional view of a second embodiment of the central part of a snowboard illustrated in  FIG. 1 ; 
           [0030]      FIG. 3  shows a cross-sectional view of a third embodiment of the snowboard illustrated in  FIG. 1 ; 
           [0031]      FIG. 4  shows a cross-sectional view of a fourth embodiment of the snowboard illustrated in  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0032]    Common elements are marked with the same reference numbers in all the figures. 
         [0033]      FIG. 1  shows a cutout view of the cross-section of a first example embodiment of a snowboard  100  according to the invention; 
         [0034]    The snowboard  100  is composed of a sandwich structure formed by a succession of layers. Thus, the sandwich structure of the snowboard  100  is classically composed of:
       a core  110 ;   lower  121  and upper  122  skins covering the lower surface and upper surface respectively of the core  110  and protecting it from all external elements that might damage it, and particularly water; the lower  121  and upper  122  skins provide the necessary stiffness to the snowboard  100  and are classically composed of fibres and resin:   possibly, special lateral reinforcement  130  to provide lateral protection of the core  110  over the entire length of the snowboard  100 ;   edges  140  on the periphery of the surfboard  100 ;   a bottom surface  150  destined to come into contact with snow and that makes snowboarding possible;   possibly an upper surface  160  providing protection for the top of the sandwich structure sensitive to water;   inserts  170  for screwing attachments for the practice of classical alpine snowboarding and also for the practice of nordic skiing.       
 
         [0042]    The snowboard  100 , also referred to as the board in the remainder of this description, has the special feature that it comprises a core  110  in two separate parts. 
         [0043]    According to the first embodiment illustrated in  FIG. 1 , the core ( 110 ) is formed from two parts thus forming two half-cores  111  and  112  extending in the longitudinal direction along the longitudinal axis of the board  100 , in the median plane of the board. 
         [0044]    The half-cores  111  and  112  are preferably made of wood, but the two half-cores could also be made of polyurethane foam or any type of material classically used for the construction of a snowboard or equipment for the practice of sliding sports on snow. 
         [0045]    The board  100  according to the invention also comprises a central element  180  made of polymer, advantageously ABS (Acrylonitrile-Butadiene-Styrene) or elastomer or a rubber material, between the two half-cores  111  and  112 . The term polymer refers equally to natural polymers and to synthetic or artificial polymers, and mixes of polymers. 
         [0046]    According to one variant embodiment, the central element  180  can also be formed by a composite material combining different mechanical, chemical properties, etc., and different materials. For example, the central element  180  may be formed by the combination of different polymer materials, for example a part made of ABS in contact with the cores and a central part made of polyethylene or possibly the combination of a polymer material (for example rubber) and a plant tissue (for example cork). 
         [0047]    According to another example embodiment, the central element  180  can also be made from wood varieties that advantageously have natural resistance to moisture. However, this central wood element is not designed to resist stresses from the core. 
         [0048]    In this first embodiment, this central element made of polymer  180  is composed of two independent parts  181 ,  182  with an approximately rectangular shape extending over the entire length of the board  100  on each side of the median plane of the board  100 . Obviously, the two parts can have different shapes depending on the design of the board and the required type of cut profile. Example embodiments will be described below, particularly with reference to  FIGS. 4 and 5 . 
         [0049]    The two parts  181 ,  182 , are held together non-permanently and reversibly by special connecting means. 
         [0050]    These connecting means may for example by made by temporary (non permanent) gluing of two parts  181 ,  182  by means of an adhesive layer reversibly fixing the two parts  181 ,  182 . The purpose of using this adhesive layer is to facilitate positioning, to temporarily retain the two half-cores  111 ,  112  during assembly of the board  100  and to prevent resin from entering between the two parts  181 ,  182  during manufacturing of the board  100 . 
         [0051]    A layer refers to a physical layer, for example a sheet or foil deposited between the two parts of the central element, but also a thin sprayed layer of a liquid agent. 
         [0052]    According to another variant embodiment, the two parts  181 ,  182  of the central element  180  are held together non-permanently and reversibly by magnetic attraction between the two parts  181 ,  182 . 
         [0053]    In this variant embodiment, the two parts  181 ,  182  are plasto-magnets, in other words they are made of composite materials formed from a magnetic powder or a permanent magnet and a thermoplastic or thermosetting binder. These plasto-magnets are manufactured by high pressure injection or by cold compression. Classically, the magnetic powders can be magnetic power with permanent magnetisation, for example based on neodymium, ferrite, iron or even boron. These plasto-magnets are magnetised either while these parts  181 ,  182  are being moulded, or after moulding. 
         [0054]    Regardless of what type of bond is used to hold the two parts  181 ,  182  together reversibly, the connection means are designed such that they generate a sufficiently high retaining force to be able to resist resin pressure applied when the board is being manufactured, so as to prevent any resin from entering between the two parts  181 ,  182  and consequently between the two cores, while allowing manual tearing or separation of the two half-cores without the use of any special tools. 
         [0055]    The two parts  181 ,  182  forming the central element  180  can also be separated by an additional layer  183 , for example a sheet or foil made of polytetrafluoroethylene (PTFE), designed to prevent any adhesion between two polymer parts  181 ,  182  during the resin application operation during manufacturing of the board  100  in the factory. 
         [0056]    The central element  180  is also intended to advantageously form a protection element and a lateral reinforcement element at each half-core  111 ,  112  when the board according to the invention is divided into two parts so as to transform it into a splitboard. 
         [0057]    The edges  140  located at the periphery of the board  100  are not joined together at the median plane of each end (i.e. at the tip and the back end of the snowboard) so as to facilitate transformation of the board, 
         [0058]    Thus, the internal configuration of the board as described above facilitates the operation to transform a classical (i.e. single-piece) snowboard into a splitboard made of two parts that can be used independently (climbing during nordic skiing) or joined together to form a snowboard for descent, by means of attachments provided for this purpose (not shown). 
         [0059]    Unlike the state of the art kit, transformation of a standard board into a splitboard is very much facilitated by the presence of the internal structure described above. 
         [0060]    The central element  180  separating the two half-cores  111 ,  112  can be made of different materials and can be in different forms, provided that they facilitate the operation to transform the board by the user and protect the edge of the half-cores against external aggression.  FIGS. 2 to 5  show a cross-sectional view of different designs of this central part  180 . 
         [0061]    According to a second embodiment shown in  FIG. 2 , the central element  380  is composed of two parts  381 ,  382  extending over the entire length of the snowboard  100 , on each side of the median plan of the snowboard  100 . Unlike the first embodiment shown on  FIG. 1 , the two parts  381 ,  382  cooperate with each other through a mortice and tenon type connection  384 . The mortice and tenon connection  384  advantageously stiffens the connection between the two parts  381 ,  382  of the central element  380 . Obviously, the mortice and tenon connection  384  is illustrated as an example and other connections could be envisaged by which the two parts  381 ,  382  engage together so as to stiffen the assembly. 
         [0062]    In exactly the same manner as for the first embodiment, the two parts  381 ,  382  of the central element  380  can be separated by a layer  383 , for example made of polytetrafluoroethylene (PTFE), designed to increase the leak tightness of the connection and preventing the introduction of resin at the connection and therefore preventing the two parts  381 ,  382  from bonding together during the resin application operation. 
         [0063]    According to a third embodiment shown in  FIG. 3 , the central element  480  is composed of two parts  481 ,  482  extending over the entire length of the snowboard  100 , with an oblique surface (i.e. not normal to the upper or lower surface of the central element  480 ). In exactly the same manner as for the first embodiment, the two parts  481 ,  482  of the central element  480  can be separated by a layer  483  designed to increase the leak tightness of the connection by preventing the introduction of resin at the connection and therefore preventing the two parts  481 ,  482  from bonding together during the resin application. 
         [0064]    According to a fourth embodiment shown in  FIG. 4 , the central element  580  is composed of two parts  581 ,  582  extending over the entire length of the snowboard  100 , with a curved contact surface that is curved either in the longitudinal plane of the board  100  as illustrated, or in the transverse plane of the board (not shown). 
         [0065]    Thus, the snowboard according to the invention has an internal structure that enables the normal practice of snowboarding on trail or off-trail, and has pre-fittings in its internal structure to facilitate separation of the board into two parts so that it can be used both for the practice of nordic skiing and for the practice of snowboarding. 
         [0066]    Thus, a user who uses the snowboard conventionally as presented above can decide, for example at the end of its life, to make a splitboard out of this special board that he already has. 
         [0067]    Due to the special structure of the board at the factory design stage, the transformation operation by the user becomes extremely easy. The user can use a simple cutting tool such as a knife or a cutter and a guide straight edge to cut the snowboard in a few minutes, without the need for any special tool or special technical knowledge. 
         [0068]    Thus, the snowboard separation or transformation operation according to the invention includes the following steps:
       cut the top face of the snowboard, for example to the median plane; this step can be facilitated even further by the presence of a visual means or a physical guide such as a groove provided on the top face  160  at the design stage of the board  100 ;   cut the top skin  122 ;   cut the bottom surface;   cut the bottom skin  121 ;   separate the central element  180 ,  280 ,  380 ,  480 ,  580  into two parts, if necessary the separation can consist of a step to break the adhesive layer holding the parts of the central element together.       
 
         [0074]    The order of the steps in the transformation operation is given as an example; obviously, it is also envisaged that the transformation operation could be done with the steps described above in a different order. 
         [0075]    All transformation operations can be done using a simple cutting tool, for example such as a cutting blade like a simple knife or a cutter. Thus, there is no need for the user to have a large number of tools for the transformation of such a board as is the case at the present time with known transformation kits according to the state of the art. It is also envisaged that light cutting tools could be used, such a mini-cutting disk or a mini-drill to cut the top and the bottom skins and for cutting the bottom surface and the top face; however, the user does not need such tools to implement the transformation. 
         [0076]    Moreover, with the invention, there is no need to perform edge filling operations to protect the sides of the cut core, because use of a central element separated into two parts during the transformation acts forms a protective edge and consequently protects the cut edge of the two half-cores against external aggression and particularly infiltration of water. 
         [0077]    In addition to the cutting operations using a cutting tool, it might be necessary to sand the edges slightly. 
         [0078]    The board can be cut in a straight line, at the median plane or elsewhere, as described above or along a different profile, for example a curved profile or a zigzag profile. To achieve this, the two half-cores and/or the central element will have appropriate shapes to make such a cut. 
         [0079]    According to a sixth more economic embodiment, there is no need to position a central element between the two half-cores. The two half-cores are then separated by an adhesive layer or by a layer that avoids polymerisation of the resin at the junction plane of the two half-cores. In this sixth embodiment, the user must perform an addition step during transformation of the board into a “splitboard” type board consisting of protecting the edges of the two cut half-cores, for example by application of a protective varnish thus protecting the two half-cores from humidity. 
         [0080]    Due to the structure of the board according to the invention, inserts for fixing attachments for the combined practice of nordic skiing and snowboarding for which attachment standards are different from the attachment standards of shell boots for the practice of snowboarding, can be included at the manufacturing stage in the factory. This is possible due to control over the cut and the distance between the inserts once the two sliding bodies have been assembled. 
         [0081]    The separation mode described in the patent and the advantageous structure of the board are such that the spacing of inserts for the single-piece board (i.e. without transformation) can be identical to the spacing of the board reassembled to a snowboard after transformation a splitboard, so that this type of insert can be positioned in the factory, which is impossible with traditional transformation methods. Users who would like to cut a standard snowboard into two parts will use a cutting tool such as a saw to cut through the entire surface of the board and will use a blade with a variable thickness that is not known when the board is manufactured, which would vary the spacing between inserts so that attachments cannot be positioned and screwed in. 
         [0082]    Due to the invention and the board separation method, the user no longer needs to use a cutting tool for which the thickness of the blade is not controlled and can vary depending on what cutting tool used. 
         [0083]    The invention has been described particularly for a snowboard, however the invention is equally applicable to a monoski that also forms a single board on which two feet are fixed and for which the internal structure is similar to a snowboard.