Abstract:
A motorized snowboard having a board with a cut out section at the rear of the board, a motor, a downwardly biased track system, and a track housing.

Description:
FIELD OF INVENTION 
     The present invention relates to motorized snowboards and, in particular, to improved designs for motorized snowboards. 
     BACKGROUND OF THE INVENTION 
     Traditionally, the sport of snowboarding is enjoyed on a downward slope. The snowboard, which is attached to the rider&#39;s feet with bindings, glides down the incline propelled by gravitational forces. The use of gravitational forces for acceleration has inherently limited the enjoyment of snowboarding to locations with an incline or towing means of propulsion. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a motorized snowboard having a motorized track assembly for propulsion. An aspect of the invention is the track assembly which is downwardly biased underneath the board towards the snow surface for keeping the track in contact with the ground at all times in order to maintain operative traction between the track and the snow covered surface. Another aspect of the invention is a cut out rear section of the board to permit the ejection of the snow by the track and thus avoid snow buildup under the board during use. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order that the invention may be more clearly understood, embodiments thereof will now be described in detail by way of example, with reference to the accompanying drawings, in which: 
         FIG. 1  is a schematic, partly sectional, side view of the motorized snowboard. 
         FIG. 2  is a bottom or top view of the board. 
         FIG. 3  is a partly sectional side view of the downwardly biased track system. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , a motorized snowboard  1  according to the present invention is shown. The motorized snowboard  1  comprises a board  2  having an open channel  14 , as shown in  FIG. 2 . The motorized snowboard  1  further comprises a track housing  3 , a track assembly  6 , a motor  5  (partially shown). 
     The board  2  may be of any shape or construction common in the art of snowboard manufacture having a substantially planar top surface  8  and bottom surface  9 , a front portion  10 , a rear portion  11  and edges  12  and  13 . As shown in  FIG. 2 , the board  2  has an open channel  14 , resembling a rectangular longitudinal open space extending rearwardly to the end of the board from about the midpoint of the board  2 . As will be more fully described herein, the forward portion of the channel accommodates the track housing  3 . The rearward portion of the channel allows for the snow that is engaged and propelled rearwards by the track assembly  6  to be ejected rearward through the open channel  14  to avoid snow building up under the board  2 . 
     Two conventional snowboard bindings (not shown) may be mounted on the top surface  8  in spaced apart relation forward and aft of the motor  5 . In operation, a rider uses the bindings to secure their feet to the snowboard. 
     Referring to  FIG. 1 , the track housing  3  is preferably a thin-walled hollow body having a flat top surface, opposing sides, and an open bottom, which houses the track assembly and overlies the forward portion of the open channel  14 . In the preferred embodiment, the open bottom of the track housing  3  is attached to the top surface  8  of the snowboard by way of a flange integrally formed around the bottom periphery thereof and attached to the snowboard by means of fasteners (not shown). 
     As shown in  FIG. 1 , the motor  5  (partially shown) may be mounted, by way of example, on the top surface of the track housing  3  by means known in the art, such as bolts (not shown). The motor  5  may be of any type known in the art suitable for use in the present application. A preferred example is a small gas powered motor with a variable drive transmission, such as a chainsaw motor, which rotates a drive shaft  40 . Although it is preferred that the motor  5  is mounted on the top surface of the track housing  3 , this particular placement of the motor  5  is not essential to the present invention. The motor  5  may be mounted anywhere on the motorized snowboard  1  where it does not hinder the operation or use of the motorized snowboard  1 . 
     A hand-held power control device (not shown) may be used to allow the rider to control the power output of the motor  5  and resultantly control the speed at which the snowboard is being propelled forward during use. The power control device may be any means known in the art which can be used to selectively control the power output of a motor  5 . A preferred power control device comprises a hand-held mechanical throttle control connected to the motor  5  by a cable. 
     The motor  5  is used to provide motive power to the snowboard by means of the drive shaft  40  which is operatively connected by any suitable means known in the art to a drive roller  25   b  on the track assembly. In a preferred embodiment, shown in  FIG. 1 , the drive shaft  40  is connected to a drive sprocket  25   a  by a drive chain  16 . The ends of the drive chain  16  are secured together to create an endless loop. 
     The drive sprocket  25   a  is mounted on a drive axle  26  and is engaged with the drive chain  16  to convert the motive power received from the drive shaft  40 , via the drive chain  16 , into rotation of the drive axle  26 . The drive axle  26  is located and rotably secured between opposing side walls of the track housing  3  by means of bearing assemblies. The drive roller  25   b  is mounted on the drive axle  26 , preferably in spaced apart relationship to drive sprocket  25   a , and engages the roller chain  21  of the continuous track  20  to transfer motion thereto. 
     Referring to  FIG. 3 , the track assembly  6  generally comprises a continuous track  20  mounted on one or more idler rollers  24  and the drive roller  25   b . Preferably, the track assembly  6  has three idler rollers  24 . The track assembly  6  is mounted inside the track housing  3 . In the preferred embodiment, the continuously looped track  20  generally comprises two strands of roller chain  21  in spaced apart relationship that are interconnected with track plates (not shown). The track plates are rigid or semi-rigid plates that are attached to the two strands of roller chain  21  and span the width of the track  20  to make up the primary structural surface of the continuous track  20 . 
     The track plates are preferably provided with traction improving structures to grip the snow covered surface during use to assist in the propulsion of the motorized snowboard  1  by the continuous track  20 . Preferably, the traction improving structures are drive paddles  23  bolted to the track plates, shown in  FIG. 3 . 
     In a preferred embodiment, the three idler rollers  24  and the drive roller  25   b  comprise barrel like rollers that span the width of the track assembly  6  and engage the two strands of roller chain  21  at each end of the roller. The longitudinal surface of each roller supports the track  20  along its width by the inwardly facing surface of the track plates, as the rollers rotate with the movement of the track  20 . In another embodiment, the three idler rollers  24  and drive roller  25   b  comprise spaced apart pairs of sprockets, wheels or a combination of sprockets and wheels that engage with the two strands of roller chain  21  and are connected by an axle. 
     Preferably, the drive roller  25   b  and one of the three idler rollers  24  are mounted between the opposing sides of the track housing  3 , with the idler roller  24  mounted rearward of the drive roller  25   b , to form a top roller assembly. 
     The other two idler rollers  24  are rotably mounted in forward and aft spaced apart relationship to one another between opposing ends of a floating frame  27  to form a bottom roller assembly. The three idler rollers  24  engage with the roller chain  21  strands and freely rotate with the chain as the drive roller  25   b  imparts rotational motion to the chain. 
     The floating frame  27  is pivotally connected to the track housing  3  by a pair of link members  28  and  29  on each side of the housing. Link member  28  is pivotally connected to the track housing  3  with a pin connection  30  at one end and is pivotally connected to the floating frame  27  at the other end by a pin connection  31 . Similarly, link member  29  is pivotally connected to the track housing  3  with a pin connection  32  at one end and is pivotally connected to the floating frame  27  at the other end by a pin connection  33 . A preferred pivotal connection is a bolted pin connection. 
     The link members and corresponding pin connections allow for the floating frame  27  to pivot between a downwardly extended position and an upwardly retracted position. A suspension member may be provided to control the movement of the floating frame  27  between the downwardly extended position and the upwardly retracted position in order to downwardly bias the track assembly  6  against the ground and to dampen the vibrations of the snowboard during use caused by the terrain. 
     In the downwardly extended position, shown in  FIG. 1 , the floating frame  27  is correspondingly pivoted downwardly below the bottom surface  9  of the board  2 . In the retracted position (not shown) the floating frame  27  is pivoted upwardly but the track assembly  6  remains in contact with the snow as will be described herein. 
     In the preferred embodiment, the suspension member is comprised of a shock absorber  42  having a compression coil spring  43 . Alternative and or multiple suspension means may be provided; for example, a linear dashpot or damper. The length of the suspension member varies between an extended length and a compressed length with the application of force. Preferably, the suspension member is biased to the extended length, in the absence of an applied force, by the compression coil spring  43  and is compressed in response to the movement and operation of the board by the weight of the motorized snowboard  1  and operator. 
     In the preferred embodiment, the suspension member is pivotally mounted at opposing ends to the floating frame  27  and the track housing  3 . The suspension member functions to limit or control the position of the floating frame  27  in relation to the track housing  3 . With the suspension member fully extended the floating frame  27  is in the downwardly extended position. When the suspension member is compressed the floating frame  27  is in the upwardly retracted position. As discussed above, the suspension member is preferably biased to the extended length in the absence of applied force and resultantly the floating frame  27  is biased to the downwardly extended position. The bias force of the suspension member functions to maintain the operative contact at all material times between the track assembly  6  and the ground that a rider is travelling over. 
     The tension of the continuous track  20  may be adjustable by means of a tensioning device. In a preferred embodiment, the tensioning device is a screw assembly  44 , shown in  FIG. 3 , which is used to selectively adjust the distance between the idler rollers  24  attached to the floating frame  27  and thereby adjust the tension of the continuous track  20 . However, the tensioning device may be formed using any means known in the art. 
     In the preferred embodiment shown in  FIG. 1 , binding mounts  17  may be provided on either side of the motor  5  to facilitate the attachment of two conventional snowboard binding to the motorized snowboard  1  in spaced apart relationship to the top surface  8  of the board  2 . The binding mounts  17  may be attached to the top surface  8  of the board  2  forward and aft of the motor  5  by any means known in the art. In the preferred embodiment the binding mounts  17  are attached to the motorized snowboard  1  by way of fasteners (not shown). The binding mounts  17  may be comprised of a planar top face that is large enough for the attachment of a conventional snowboard binding thereto and may be provided with threaded holes to facilitate the attachment of the conventional snowboard bindings thereto. When installed, the planar surface of the binding mount  17  may be parallel to, but spaced apart from the top surface  8  of the board  2  so that the bottom of the rider&#39;s boot, when in the binding, is raised up from the top surface  8  of the board  2 . 
     Other advantages which are inherent to the structure are obvious to one skilled in the art. The embodiments are described herein illustratively and are not meant to limit the scope of the invention as claimed. Variations of the foregoing embodiments will be evident to a person of ordinary skill and are intended by the inventor to be encompassed by the following claims.