Abstract:
A device allowing positioning of wheels of a snowmobile when skis leave a snowy path to continue on a road. The device comprises at least two parallel wheels positioned near each ski, a pair of cylinders placed in connection with each wheel, and controlled by a control box by a driver activating pistons to move the wheels from an upward position to a downward ground position. The upward position corresponds to wheels elevated over the ski when the piston is contracted; and the downward position corresponds to wheels in touch with the ground when the piston is extended. Means of clutch move horizontally the wheels to an external position. A spike located on an arm which supports a wheel is positioned to scratch ground ice for creating a mist when a wheel is in a scratching position.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a device for wheels for snowmobile ski allowing immediate positioning of the wheels on the ground while the snowmobile is on movement. No need to stop the snowmobile for positioning the wheels. 
     PRIOR ART 
     The present invention refers to a canadian patent application CA 2,724,925 &lt;&lt;R ETRACTABLE AND AUTOMATIC POSITIONING WHEELS FOR SNOWMOBILES &gt;&gt; filed on Dec. 10, 2010 by the same author. 
     The following applications drew our attention:
     CA 2647375 “Retractable snowmobile wheel” by Denis Beaudoin published on Jun. 8, 2010, shows a retractable wheel for a snowmobile in an extension position for driving on the ground, and in a contraction position for sliding on ice. The contraction position is automatically done by means of spring when the snowmobile slide on snow.   CA 2687708 “Retractable wheel system . . . ” by Denis Beaudoin published on Jun. 8, 2010, shows a prealably tensed spring which repositions wheels of a snowmobile in a contracted position when the snowmobile get on the snow.   U.S. Pat. No. 5,439,237 “Retractable wheel system . . . ” by Steven A. Kutchie, published on Apr. 13, 1994 shows a pivoting assembly of wheels to raise a snowmobile from the ground.   

     OBJECTIVES AND ADVANTAGES 
     There is a need in the market of snowmobiles for a retractable wheels device allowing the wheels to be automatically positioned on the ground when the snowmobile is arriving on the ground. And when the snowmobile returns on the snow, the device hides the wheels over the ski so that the wheels are no longer in contact with the snow, thereby avoiding a collision of the wheels with the snow which would risk changing the trajectory of the snowmobile. 
     The device includes:
         At least two parallel wheels, each wheel being arranged on each ski of the snowmobile, and with the space between wheels slightly bigger than the space between skis;   A wheel motor installed in connection with each wheel and controlled by a control box by the driver;   A cylinder activated by each motor and intended to move a piston between a rest position, when the piston is contracted, and an active position, when the piston is advanced;   A positioning triangle to move wheels vertically from a rest position corresponding to wheels elevated over the ski to an active position with wheels in touch with the ground;   Means of clutch to horizontally move the positioning triangle from a closed position when wheels are hidden to an external position when wheels supporting the snowmobile drive on the ground.       

     The present invention will be further understood from the following description with reference to the drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWING FIGURES 
         FIG. 1  is a perspective of a positioning triangle on a ski. 
         FIG. 2  is a perspective of the triangle with its “road with ball” 
         FIG. 3  is a view of a wheel to be installed on the triangle. 
         FIG. 4  is a perspective of the triangle activated by a piston. 
         FIG. 5  is a view of the triangle at the back of a central pivot of the ski. 
         FIG. 6  is a view of the triangle in front of the central pivot of the ski. 
         FIG. 7  is a view of a system of displacement bushing. 
         FIG. 8  is an image of the displacement bushing on the ski. 
         FIG. 9A  is a perspective of the device with an oblique support of wheels. 
         FIG. 9B  is a perspective of the oblique support with an elevated wheel. 
         FIG. 9C  is a perspective of means of tube and torsioned arm. 
         FIG. 10A  is a face view of the device with a wheel on the ground. 
         FIG. 10B  is a face view of a support plate. 
         FIG. 11A  is a face view of an alternative device, on the ground. 
         FIG. 11B  is a face view with a wheel in a horizontal position. 
         FIG. 11C  is a face view with a wheel in an oblique position. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the following description and in the accompanying drawings, the numeral numbers refer to identical parts in the various Figures. 
       FIG. 1  shows a ski  22  of a snowmobile  20  with a supporting stalk  24  fixed to the ski at pivot  26 , and the stalk is leaning towards the direction of movement  28  of the snowmobile. A female part in a shape of a sliding tube  30  is perpendicularly fixed to the ski and is welded over the ski and in front of the supporting stalk at a distance  32  from the pivot  26 . A seesaw  34 , located over the ski and near the supporting stalk  24 , and having a near extremity  36  having a male extension  38  which fits into the sliding tube  30  and intended to slide inside so that the seesaw  34  will be at one time close to the supporting stalk  24  and at another time horizontally moved outside the ski  22 . The seesaw  34  comprises a triangular body  40  having a side end  42  connected to the near extremity  36  by a bent junction  44 . A top end  46  of the triangular body includes a tip  48  adapted to receive the end of a piston. The triangle comprises a third end, remote,  50  to which a hub  52  is fixed and intended to hold a wheel. The remote end  50  is positioned beyond the pivot  26  and has an effect of push against a back part of the ski by oscillating in tandem with the near extremity  36  lead by the seesaw  34 . The remote end  50  supports a curved structure  54  which has a free extremity which is a crowbar  56  serving as means of tie of the triangle to the ski when the triangle is moving towards the outside of the ski and revolving under a push of the piston and making the hub fall to allow the wheel to touch the ground. 
       FIG. 2  shows the triangular body  40  with its top end  46  and the seesaw  34  connected with the near extremity  36  by the bent junction  44 . The near extremity  36  is extended by the male part  38  connected perpendicularly to the plane of the triangular body  40 . The male part includes a spiralled channel  62  inside which a ball  66  is shown. The spiralled channel is twisted  64 . One sees the hub  52  with openings for tightening  60  in the tip  48 . 
       FIG. 3  shows a wheel  68  with a hole  70  in its center. 
       FIG. 4  shows a cylinder  72  with an electric motor  74  and prolonged by a piston  76  inserted in the tip  48  of the triangular body  40 ; the piston is shown passing over the sliding tube  30 . The sliding tube  30  is fixed to a plate  69  of steel and welded on the ski at the weld point  39 . The hub  52  is shown. 
       FIGS. 5 and 6  show the triangular body  40  installed in two different positions; in  FIG. 5  the triangle is entirely placed behind pivot  26 . In  FIG. 6  the triangle is placed in front of pivot  26 . 
       FIG. 7  shows a system of concentric bushings comprising a first bushing  31  comprising an arm  49  intended to be moved. The first bushing surrounds the male part  38  and comprises a first keyway  80  intended to receive a first ankle  82  perpendicularly installed on the male part  38 . The first bushing includes a second keyway  84  intended to receive a second ankle  86 . One sees a second concentric bushing  33  surrounding the first bushing  31  and including the second ankle inwardly jutting out of the second bushing  33  and intended to ride the second keyway to impart an ark of rise and lower an axle  65  of an internal wheel  68 ′ to the ski  22 . In the sliding tubes  30  welded to the ski at a periphery are inserted the system of concentric bushings. An abutment  78  limits the rotation of the second bushing  33 . One sees the near extremity  36  and the curved junction  44 . 
       FIG. 8  shows a perspective of the displacement bushing on the ski  22  close to the supporting stalk  24 . One sees the arm  49  on the first bushing  31 , the abutment  78 , the axle  65  of an additional wheel inside the ski, and the first  82  and second  86  ankles defining the course of rotation of the male part  38  and the axle  65  respectively. A first keyway  80  is shown. 
       FIG. 9A  shows the supporting stalk  24  of the snowmobile at the top of which a small dome  25  is shown and at the foot of which a pivot of the ski is shown. Near the stalk is an oblique tube of sliding  30 ′ positioned at an angle  88  and maintained by means of tie, a near tie  41 ″ and a remote tie  41 ′ of the ski  22 . At the near extremity  36  of the sliding tube is a central axis of an interior stalk  53  with a circumference  51  intended to be subjected to a piston; this action can be applied in a remote plane of circumference. The near extremity of the interior stalk  53  allows to hold a twisted arm  35  which has an added twist  35 ′. 
     At the end of the twisted arm is the hub  52  of the wheel  68  which is currently on the ground, but which can make a trajectory  45  as far as the small dome  25  near the supporting stalk  24  when the oblique sliding tube will be oriented at a smaller angle  89 . The wheel can also make a trajectory as far as a bigger dome  25 ′ and be in a position such as seen in  FIG. 9B . One sees the cylinder  72  and the arm of axle  65 . 
       FIG. 9B  shows the oblique tube  30 ′ as in  FIG. 9A  supporting the wheel  68  almost at the end of its trajectory near the bigger dome  25 ′. The piston  76 , the cylinder  72 , the arm of axle  65  and the ties  41 ′,  41 ″ are shown. 
       FIG. 9C  shows the sliding tube  30  and the twisted arm  35  comprising a twist  35 ′ intended to minimize the spread of the wheel when risen. One sees the arm of axle  65  in a second plane and the beginning of the internal stalk  53 , fitting into the tube. One sees the hub  52 , the piston  76  and the cylinder  72 . 
       FIG. 10A  shows a perspective of the ski  22  with its back  22 ′ and its front part  22 ″, the ski moving in the direction  28 . The supporting stalk  24  is shown in a cut section. One sees the piston  76  leaning against a plate of transation  90  of the wheel  68 . The plate surrounds a bushing  43 . The bushing  43  is approximately 15° oriented and is surrounding a threaded  47  extension  27  which prolongs in a transverse bolt, already existing, as far as the supporting stalk  24  and the central pivot  26  of the ski. 
     The bushing  43  is welded to the plate  90  which holds the wheel  68  by its hub  52 . When the plate turns, it is moving away the wheel  68  up to the dome  25 . Inside the bushing  43  there is an axle  55  which has a recess coinciding with a same recess  75  on a steel plate  69  which is fixed by bolts  73  to sides  22 ′″ of the ski  22 . The axle  55  is eccentric with regard to the extension  27  which allows during the rotation of the bushing  43  and the wheel  68  a close positioning over the ski, and left and right movements of the wheel towards dome  25 . The plate  69  has a perpendicular deflector  59 . 
       FIG. 10B  shows the front  22 ″ and the sides  22 ′″ of the ski having a bolted  73  plate  69  possessing the perpendicular deflector  59  which protects the passage of the wheel against rocks or obstacles. Threads  47  of the extension  27  hold a nut  57  of six ( 6 ) faces and a washer  58 . The axle  55  surrounding the extension  27  is shown. 
       FIG. 11A  shows the ski  22  wherein piston  76  and its cylinder  72  are attached to the ski in a pivot of cylinder  79 . At the end of the piston the plate  90  is attached at a pivot of piston  94  and is also attached to the ski at a fixed point corresponding to the central pivot  26 . The plate is used to support the wheel  68  which is attached on it by the hub  52 . The plate and the wheel are shown in a vertical position. One sees attached to the plate a spike  96  used to scratch the ice, as well as its spring  97  maintained in a section located between each stopper  98  and  98 ′. When the spike and the spring are oriented horizontally and in the space of the ski or of its runner  23 , then they have no effect on the ice. 
       FIG. 11B  shows the plate  90  and the wheel  68  positioned horizontally with the contracted piston  76 ; the spike  96  according to its length could exceed the depth of the runner  23 ; in that case the spring  97  would limit the effect of the spike. One sees the hub  52  and the stoppers  98 ,  98 ′ of the spring. One sees that the cylinder is supported by the front skis and the wheel goes down from the back of the central pivot  26 . 
       FIG. 11C  shows the plate and the wheel  68  making an angular movement downward from the central pivot  26  of the ski. The cylinder  72  and the piston  76  maintain the plate in its position. The spike  96  and the spring  97  are in a lower position, oblique, directed towards the front, and continue to scratch the ice. It is important that the wheel go down from the back towards the front for preventing the wheel to be removed away from the ski when touching the ground if there is too much friction. The descent of the wheels from the back to the front renders the wheel capable to touch the ground and to raise the snowmobile gradually while the snowmobile is running, without risk of accident. 
     SUMMARY 
     (FIGS.  9 C, 10 A, 11 A) A device of retractable wheels for a snowmobile  20  having a pair of skis  22 , 22 ′, each ski comprising rotation means transversally disposed about an axis ( 27 , 55 ) of said ski, a rectractable wheel device disposed to effect contact with the ground when on an internal side of either ski. The device comprises a triangular body  90  ( FIG. 11A ) installed in a first plane which comprises three extremities among which:
         a first near extremity comprising a rotating part  43  ( FIG. 10A ) comprising means of rotation disposed perpendicularly  51  ( FIG. 9A ),  38  ( FIGS. 1&amp;7 ) of the first plane, the means of rotation comprising a rotative male-female part  43  moving around a male-female center axle  55 ;   a remote end  50  comprising a hub  52  substantially perpendicular to the plane of the triangular body and intended to receive a wheel  68 ;       

     The hub being connected with the male part by a twisted arm  35  comprising means of positioning in rotation intended to vary the position of the wheel between a position against the ground and a hidden position behind a high structure of the ski;
         the third extremity of the triangular body comprising means to apply a rocking movement with regard to the first extremity thus making it revolve.       

     The third extremity being radially located with regard to a pivot center  55 , thereby allowing the displacement of a circumferential push from 0 to 120°. 
     The movement is intended to raise and to lower the hub  52  between the position against the ground and the hidden position;
         the first extremity is a pivot center of the male part  38 , and the third extremity is circumferentially located with regard to the pivot center, allowing the displacement of a circumferential push from 0 to 90°;   the third extremity is remotely located  51 ′ at a distance from to the first plane, thus creating a second plane parallel to the first plane;   the means of rotation can be a tube ( 30 , 30 ′) including a closer strip  41 ′ and a remote strip  41 ″ comprising means to allow the rotation of the male part  38 . The closer  41 ′ and remote  41 ″ strips are continuous and form a female tie forming the tube  30  as means of rotation and intended to contain the male part  38 . The remote strip  41 ″ is vertically oriented at 1° to 45° with regard to the closer strip.   The twisted arm comprises a curve which positions the hub at an angle corresponding to an orientation of the male part. The positioning angle  88  comprised between 1 and 45°. It also comprises a twisting  35 ′ intended to minimize the spreading with regard to a high structure of the ski.   The means of tube can be a sliding tube  30  used in connection with means permitting to enter and exit the male part. Such means are in the shape of a spiralled channel  62  which allows to move horizontally and positively in the sliding tube with the aim to push away the triangular body towards the outside of the ski and so allow the wheel to touch the ground under the influence of the rocking movement produced by the pushing away of the triangular body.   The top end  46  is a tip  48  which under the effect of a piston  76  positioned above the ski produces a rocking movement  34  with regard to the near extremity and intended to raise and to lower the hub. The piston is activated by an electric motor  74  controlled by a control box by the driver.   The spiralled channel  62  is located around the male part and a ball  66  is partially inserted into the sliding tube and partially into the spiralled channel so that with the rocking movement, at the same time the male part pivots and moves forward and back when the spiralled channel is moving around the ball.       

     The retractable and automatic wheel device is placed on a ski preferentially at the level of the supporting stalk  24  but it can be also placed in front or behind the supporting stalk. 
     The supporting stalk comprises a central pivot  26  and the means of rotation  43  are thereby located near the supporting stalk, from 0 to four inches towards the rear and oriented between the two skis. The central pivot comprises an extension  27  holding the axle  55  surrounded by a rotation bushing  43  attached to a plate of translation  90 . The axle  55  is eccentric with respect to the extension  27  ( FIG. 10A ). 
     The rotative bushing  43  is rotating around the axle  55  which is oriented from 0 to 25° from the central pivot  26  and intended to position the wheel in high position above the ski and displaced according to a left-right orientation of the wheel. 
     The plate of translation  90  comprises a deflector  95  and a spike  96  perpendicularly disposed and intended to scratch snow and ice to throw a mist of snow to cool a part of the snowmobile, the spike comprising means of spring  97  intended to limit between a first and a second stoppers ( 98 ,  98 ′) and to return the movement of the spike. 
     The spring is positioned around one of a group of elements comprising the hub  52 , the central pivot  26  and being removable and being tidied up. 
     The extension  27  is surrounded by the axle  55  angularly fixed from 0 to 25° from a side of the ski. 
     The bushing  43  fixed to the plate of translation  90  is mobile and concentric around the axle. The plate  90  being welded angularly to the bushing  43  thereby causing a vertical position to the wheel when riding against ground and a slanted position when resting above the ski. 
     A plate of steel  69  is fixed on the ski by bolts  73  and comprising a recess  75  corresponding to a like recess on the axle  55  and intended to prevent the axle from revolving. 
     The plate of steel  69  comprises an axle guard  59  pointed and being bent perpendicularly and intended to deviate stones and obstacles from axle  55 , the axle guard acting in combination with a deflector  95  to deflect snow destined to cool radiators. 
     An additional device of wheels can be also added on the inside of a ski, in addition to the outside face. A system of concentric bushings allowing the elevation or the lowering of the wheels can be used. The system includes:
         a first bushing  31  comprising an arm  49  intended to be moved mechanically or manually. The first bushing surrounds the male part  38  and comprises a first road  80  intended to receive a first ankle  82  perpendicularly placed on the male part. The first bushing also includes a second road  84  intended to receive a second ankle  86 ;   a second concentric bushing  33  surrounding the first bushing  31  and which includes the second ankle inwardly jutting out of the second bushing  33  and intended to cross the second road to grant an arc of raising or lowering of an arm of axle  65  of an internal wheel  68 ′ of the ski  22 . An abutment  78  is used to limit the rotation of the second bushing  33 . The raises of the outside and internal wheels corresponding to the first and second roads  84  and  86  can be equal or not according to the diameters of the wheels. For example, if the internal wheel is smaller than the outside wheel, the second road  86  will be longer than the first road  84  because the small wheel will need more running to lean on the ground, or on the contrary thanks to the abutment  78 . A hydraulic motor with pump is added to the snowmobile to push a hydraulic pressure in cylinders.       

     It is to be clearly understood that the instant description with reference to the annexed drawing is made in an indicative manner and that the preferred embodiments described herein are meant in no way to limit further embodiments realizable within the scope of the invention. The matter which is claimed as being inventive and new is limited only by the appended claims. 
     
       
         
               
             
               
               
               
               
               
               
             
           
               
                   
               
               
                 PARTS 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 20 
                 Snowmobile 
                 22 
                 Skis 
                 22′ 
                 Back ski 
               
               
                 22″ 
                 Front ski 
                 22′″ 
                 Sides 
                 23 
                 Wear runner 
               
               
                 24 
                 Supporting stalk 
                 25 
                 Small dome 
                 25′ 
                 Bigger dome 
               
               
                 26 
                 Central pivot 
                 27 
                 Extension 
                 28 
                 Direction of  
               
               
                 30 
                 Sliding tube 
                 30′ 
                 Oblique tube 
                   
                 movement 
               
               
                 31 
                 First bushing 
                 32 
                 Distance 
                 33 
                 Second bushing 
               
               
                 34 
                 Seasaw 
                 35′ 
                 Twist 
                 35  
                 Rigid twisted arm 
               
               
                 36 
                 Near extremity 
                 37 
                 Periphery 
                 38 
                 Male part 
               
               
                 39 
                 Weld 
                 40 
                 Triangular body 
                 41′ 
                 Remote tie 
               
               
                 41″ 
                 Near tie 
                 42 
                 Side end 
                 43 
                 Bushing 
               
               
                 44 
                 Curved junction 
                 45 
                 Trajectory 
                 46 
                 Top end 
               
               
                 47 
                 Thread 
                   
                   
                   
                   
               
               
                 48 
                 Tip 
                 49  
                 Arm 
                 50 
                 Remote end 
               
               
                 51,  
                 Circumferences 
                 52  
                 Hub 
                 53 
                 Interior male part 
               
               
                 51′ 
                   
                   
                   
                   
                   
               
               
                 54 
                 Curved structure 
                 55 
                 Axle 
                 56 
                 Crowbar 
               
               
                 57 
                 Nut 
                 58 
                 Slice 
                 59 
                 Axle Guard 
               
               
                 60 
                 Openings 
                 62 
                 Spiralled channel 
                 64 
                 Twisted part 
               
               
                 65 
                 Arm of axle 
                 66 
                 Ball 
                 68 
                 Wheel 
               
               
                 68′ 
                 Internal wheel 
                 69 
                 Steel plate 
                 70 
                 Hole of the wheel 
               
               
                 72 
                 Cylinder 
                 73 
                 Bolt 
                 74 
                 Electric motor 
               
               
                 75 
                 Recess 
                 76 
                 Piston 
                 78 
                 Abutment 
               
               
                 79 
                 Cylinder pivot 
                 80 
                 First keyway 
                 82 
                 First ankle 
               
               
                 84 
                 Second keyway 
                 86 
                 Second ankle 
                 88 
                 Positioning angle 
               
               
                 89 
                 Small angle 
                 90  
                 Plate of translation 
                 94 
                 Pivot of the piston 
               
               
                 95 
                 Deflector 
                 96 
                 Spike 
                 97 
                 Spring 
               
               
                 98,  
                 Stoppers 
                   
                   
                   
                   
               
               
                 98′