Abstract:
A ski or snowboard includes a metal layer having integral flanges projecting from its opposite sides to define a cavity for receiving a base layer. Several additional layers of laminated wood and in some versions synthetic polymer or carbon are pressed and bonded together on the metal layer. A method of manufacturing includes a support plate which holds a base layer and edge members received in a slot in the perimeter of the base layer. Additional layers of the ski or snowboard are successively laid on the base layer and pressed and bonded together.

Description:
[0001]    The present invention generally relates to snow skis and snowboards and methods of making the same. Hereinafter the term “ski” refers to skis or snowboards. 
       BACKGROUND OF THE PRESENT INVENTION 
       [0002]    One present conventional method of making skis and snowboards uses a mold made from relatively thick aluminum plate which is laboriously carved out in accordance with the shape of the ski. A base layer of the ski is placed in the mold and then separate edge members are placed in the mold at the outer perimeter. Epoxy resin is then painted into the mold to wet the base layer and edge members. Layers of fiberglass wet with resin or other layers of zicral aluminum or carbon, are then laid into the mold. A core, pre-cut typically from wood, is then laid on top in the mold and more epoxy resin is repainted in the mold on the core and then two more layers of fiberglass are laid on top of the core. More epoxy is applied and a top layer which may have graphics, is laid on the top. The mold with the assembly of layers therein is then placed in a press under pressure and heat to impart a camber to the assembly and to cure the resins. When the assembly is removed from the mold the product is very rough. The finishing process is very expensive and takes several more steps. First a band saw is used to cut the fiberglass and glue hanging out between the layers. Then up to twenty sanding processes to get the skis or boards to a final finish state may be required. At this point extensive final base finishing is required as the product tends to change shape while curing. It takes several stone grinding and edge finishing passes to get a finish that is usable. 
       OBJECTS OF THE PRESENT INVENTION 
       [0003]    One object of the present invention is to provide novel and improved skis and snowboards as well as methods of making the same. 
         [0004]    A further object of the present invention is to provide a novel method of making skis and snowboards that will facilitate the manufacture of different ski shapes and sizes while avoiding the need to create a new mold with the desired shape or size of the ski for each new ski design. Included herein is a novel method and assembly of ski layers and edges that will permit skis of different shapes and sizes to be made without the need of conventional molds or the need to make a new mold for every different model or size of the ski. 
         [0005]    A further object of the present invention is to provide skis or snowboards that are easier and less expensive to manufacture than some conventional skis and snowboards and yet will provide a stronger structure and allow improved performance. 
         [0006]    A still further object of the present invention is to provide methods of making skis which are an improvement over conventional methods such as that described above from the standpoints of labor, cost, versatility, and efficiency. 
       SUMMARY OF PREFERRED FORMS OF THE PRESENT INVENTION 
       [0007]    A ski or snowboard in accordance with one preferred embodiment of the present invention includes a metallic layer preferably a plate of high carbon steel cut with the desired ski or snowboard shape (in plan view). A recess is formed in one side of the plate in the shape of a base layer which is received in the recess. The recess cut into the plate leaves integral flanges projecting downwardly around the edge portions of the plate to serve as the edges of the ski. A base layer is cut preferably from a sintered polyethylene plastic such as P-Tex 7500 and fits snugly within the flanges where it is bonded to the plate. The plate with the base layer is laid on a generally flat support surface and then successive core layers and a top layer are applied with resin to the metal plate on the side opposite the base layer. The assembly is then drawn or pressed together and heated to cure the resin. 
         [0008]    In another preferred form of the present invention, the core and top layers are pre-cut to the desired ski shape and assembled one on top of the other on a base layer with resin in between the layers. A sheet of material from which the base layer is made is supported on a generally flat support plate and has a slot or other opening cut about its perimeter defining the shape of the ski in plan view. Edge members which will form the edges of the ski are inserted in the slot. All the layers are pressed and bonded together with the edge members and heat is applied to cure the resin. In order to make skis of different sizes or shapes the slot cut into the base layer is simply changed accordingly through a computer which controls the cutting of the slot. This avoids the need of making a new mold as in conventional practice. 
     
    
     
       DRAWINGS 
         [0009]    Other objects and advantages of the present invention will become apparent from the detailed description below taken in conjunction with the attached drawings in which: 
           [0010]      FIG. 1  is a perspective view of a ski constituting a preferred embodiment of the present invention with a mid-section broken away and shown in cross-section to show the layers of the ski; 
           [0011]      FIG. 2  is a transverse and exploded, cross-section of the ski of  FIG. 1  showing the various layers of the ski; 
           [0012]      FIG. 3  is a perspective view of a sub-assembly of another ski during its construction on a support plate; 
           [0013]      FIG. 4  is a transverse and exploded view of the ski being constructed in  FIG. 3  showing all of its various layers; 
           [0014]      FIG. 5  is a plan view of the sub-assembly of the ski of  FIG. 3  but before the core layer  44  shown in  FIG. 3  is laid; and 
           [0015]      FIG. 6  is a fragmental, cross-sectional view of edge members inserted in a base layer of the ski of  FIG. 4 . 
       
    
    
     DETAILED DESCRIPTION 
       [0016]    Referring to the drawings in detail, there is shown for illustrative purposes a ski  10  constructed in accordance with one preferred version of the present invention. Referring to  FIG. 1 , the ski includes a first layer  12  made preferably of a sheet of structural carbon steel, for example, 1.8 mm thick. At the perimeter of layer  12  is an integral, continuous, flange  14  projecting downwardly from the main body  16  to define a cavity for receiving a base layer  18  formed preferably from a sheet of P-Tex 7500 which is a sintered polyethylene plastic, for example, 1.3 mm thick. The depth of the cavity in layer  16  is the same dimension, 1.3 mm, as the thickness of base layer  18  so that it fits snugly in the cavity as shown in  FIG. 1  where it is glued to layer  12 . The width of the flanges  14  in the shown embodiment is, for example, 3 mm. Flanges  14  form the edges of the ski  10  and eliminates the need of separate edge pieces to be attached to the ski as required by conventional ski designs and constructions. The above assembly may be performed on a generally flat support surface which will also support the ski layers while the core and upper layers are assembled as now will be described. 
         [0017]    The core of the ski  10  is formed by two pre-cut core layers  20  and  24 . For example, core  20  layer is approximately  1 . 0  mm thick and made of a wood like vertically laminated bamboo. Other woods like aspen, or for very high performance, pre-cured carbon Kevlar may also be used instead. Layer  20  is glued to the top surface of the steel layer  12  which is preferably rough-sanded to increase bonding. The core material provides the necessary flexibility or stretching needed at the bottom of the ski. 
         [0018]    The main core  24  is pre-cut and also preferably made of vertically laminated bamboo having a thickness varying from about  2  mm at the tip and tail to about  12  mm at the center waist of the ski. Of course other woods like oak or maple may be used for layer  24  instead of bamboo. Layer  24  is laid on a film of epoxy on top of layer  20 . The top of the ski is under compression when the bottom of the ski stretches so the top layer  26  is made from a very hard compression-resistant wood like oak, bamboo or maple, 2 to 3 mm thick depending on the performance required out of the ski. Top layer  26  is laid on a film of resin on the top of core  24 . 
         [0019]    The above assembly is pressed or drawn together with a predetermined camber as the epoxy is cured by heat. The camber or final shape of the ski can be obtained in any suitable manner. However preferably, the layers are drawn or pressed together by placing them in a vacuum bag where the vacuum in a bag draws or presses the layers together with the desired camber. Also the layers can be cured while being pressed together in a vacuum in an oven. The thermal qualities of the ski layers can be such as to shape the ski upon heating and curing the layers. Alternatively the camber shape can be provided by pressing the ski layers against a curved surface during the curing step. Any other method may be employed to provide a camber shape. 
         [0020]    Referring now to  FIGS. 3 ,  4  and  5 , there is shown another ski construction and method of making it using a generally planar support member  30 , preferably made of a generally rectangular, aluminum plate for example, 10 mm thick, 2200 mm long and 500 mm wide. Two ski sub-assemblies  32  for two identical skis are shown on plate  30 , however all of the layers of each ski are shown in  FIG. 4  as will be described below. In the preferred embodiment, the top surface of plate  30  has a recess 1.3 mm deep formed in it as best shown in  FIG. 3  at  34  for receiving a sheet of base material  36 , sintered polyethylene plastic, preferably P-Tex 7500 from which the base layer  37  of the ski is cut with computer controlled cutting equipment. Recess  34  in the specific embodiment is rectangular and snugly receives the rectangular base material sheet  36  with their top surfaces flush with each other. This relationship secures base sheet material  36  against horizontal movement on plate  30 . Base material sheet  36  in the specific embodiment is 2000 mm long, 328 mm wide and 1.3 mm thick. Referring to  FIG. 5 , base material sheet  36  is cut to provide a slot or other opening  38 , for example, 2 mm wide along the entire perimeter of the base layer  37  of the ski as seen in plan view in  FIG. 5 . 
         [0021]    Referring to  FIG. 4 , elongated steel edge members  40  are provided in slot  38  to provide the edges of the ski. In one embodiment the edges are 2 mm wide and 1.8 mm in depth, and have an inverted “L” shape cross-section to allow the top of the edge member  40  to engage the base layer  37  as shown in  FIG. 6  to prevent the edge members from moving downwardly through slot  38 . In addition, the edge members  40  may be further secured in place by using magnets  60  positioned under the edge members (as shown in  FIG. 6 ) or the aluminum support  30 . The edges of the ski can be formed by one continuous or a plurality of edge members  40 . Since the shape of the base layer  37  is determined by the slot  38  cut into the base sheet  36 , different ski shapes are easily made by varying the cut through the computer which controls the cutting machine. 
         [0022]    One or more layers  42  in the shape of the ski in plan view and made of structural material such as 1 mm thick sheets of fiberglass and fiberglass and Kevlar mix is wet with epoxy resin and laid on the base layer  37 . 
         [0023]    A core layer  44  of the same shape as previous layer  42  and preferably made from a vertically laminated wood such as poplar, ash or bamboo or a combination of them depending on the performance requirements, is laid on a film of epoxy resin on the previous layer  42 . As shown in  FIG. 5 , core layers  44  of both skis being assembled on the support plate  30  are laid together through their interconnection by tabs  46  which are eventually cut away from the skis after they are completed. Tabs  46  facilitate positioning and securement of the core layers  44 . Further in this regard, it is preferred that upstanding abutments  48  or posts be provided to project upwardly from the support plate  30  and engage the core layer  44  and the other layers above the core layer  44  to be described below. Abutments  48  serve to secure the layers in position and may be provided in holes formed through the support plate  30  at the positions along the outside edges of both cores  44  as shown in  FIG. 3 . Abutments  48  are removable from their respective holes however magnets or any other suitable means may be used to keep them in place during assembly of the skis on the plate  30 . 
         [0024]    A layer or layers  50  of composite materials such as fiberglass and glass basalt mix are laid on a film of epoxy resin on the core layer  44 . Layer  50  can also be a 0.5 mm thick sheet of high grade aluminum for certain skis requiring high speed use. 
         [0025]    The top layer  52  is a 0.5 mm sheet of nylon, such as for example, Intersport 8210 which is laid on a film of epoxy resin on the previous composite layer  50 . Any suitable graphics may be applied to top layer  52  before it is laid. The assembly is now complete and the next step is to draw or press the layers together preferably by using a vacuum bag or other vacuum chamber which receives the assembly. Additionally the assembly is heated in an oven to cure the resin. The oven may have a vacuum in the heat chamber to squeeze the layers together as the resin is cured. 
         [0026]    The support plate  30  may have its forward portion curved upwardly to impart that shape to the ski after the ski layers are drawn or squeezed together while the resin is curing. Also if it is desired to have the rear end of the skis gradually curved upwardly, the support plate  30  can be formed with a recess (not shown) to receive an insert having the desired shape to impart to the end of the ski. Any other suitable method may be used to provide a desired shape or camber to the ski such as described above. After the ski layers are squeezed together and the resin is cured, only minor finishing operations remain like sanding, trimming the core  44 , and beveling the edges  40  and varnishing. 
         [0027]    In another embodiment and method of the present invention, the support plate  30  has a generally flat top surface without the recess  34  used in the embodiment of  FIG. 3 . However the support plate  30  is provided with abutments and/or clamps or any other suitable means for securing the ski layers in fixed horizontal position during their assembly. 
         [0028]    It will be seen from the above that the methods and ski assemblies of the present invention for making skis avoid the need of a mold in the conventional sense. Indeed skis of different shapes and sizes may be made using the above ski assemblies and methods without requiring molds for each new ski shape or size. Moreover the present inventions do not require any mold for bonding the edge members to the base of the ski. It will also be seen that skis may be made in accordance with the present inventions to increase strength and durability of the ski while at the same time reducing labor and other costs of manufacture. 
         [0029]    Although certain preferred embodiments and forms of the present invention have been shown and described above, it will be apparent to those skilled in the art that certain modifications and variations of the skis and construction methods of the present invention may be made but without departing from the scope of the present invention indicated in the appended claims.