Abstract:
A snow groomer includes a movable platform, a prime mover mounted to the platform and a grooming drum rotatably driven by the prime mover for rotation in a direction opposite the traveling direction of the snow groomer. The grooming drum includes axially spaced apart and radially protruding ribs that extend circumferentially around the drum. The ribs include circumferentially spaced apart apertures and the apertures of each rib are aligned with the apertures of the other ribs. Elongated cutting teeth extend through the apertures of the ribs and have a cross-sectional area that is smaller than the apertures such that the cutting teeth are free to vibrate within the apertures as the drum rotates, thereby enhancing the pulverization of chunks of snow and ice.

Description:
RELATED APPLICATIONS 
     The present application is a continuation-in-part of U.S. patent application Ser. No. 09/134,265, filed Aug. 14, 1998 now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to groomers for snow and, more particularly, to a snow groomer assembly for grooming snow. 
     2. Description of the Related Art 
     It is known to groom snowmobile trails by the use of drags pulled behind a tractor. These drags cut off the tops of the bumps or moguls and fill in the valleys. The resulting trail looks very smooth. However, the snow filling the valleys is made up of relatively large chunks with minimal compaction and therefore does not bond together to form a hard durable surface. The tops of the shaved off moguls are quite hard. As a result, as snowmobiles traverse the newly groomed trail, the loose snow in the valleys is compacted and displaced and the trail becomes bumpy in a short time. 
     It is also known to use a tiller to groom snow on a nordic ski trail and alpine ski slope. The tiller has a rotating cylinder that cuts up a surface of a snow pack on the trail or slope. Although the above tiller has worked well, it suffers from the disadvantage that the tiller works on the snow pack as a whole, thereby impacting only a minimal number of individual particles. Snow on heavily used alpine ski areas often turns into chunks of ice (called death cookies). It is desirable to turn those ice chunks back into snow without compaction to provide a good ski surface. Current equipment such as groomers or tillers will not do this. Thus, there is a need in the art to provide a snow groomer that acts on the individual particles of a snow pack, thereby changing the actual structure or make-up of the snow pack and to then densely compact the particles into a smooth surface. 
     SUMMARY OF THE INVENTION 
     It is, therefore, one object of the present invention to provide an improved snow groomer assembly for grooming snow on snowmobile trails and alpine ski hills. 
     It is another object of the present invention to provide a snow groomer assembly that acts on individual snow particles and changes the structure of a snow pack. 
     To achieve the foregoing objects, the present invention is a snow groomer assembly. The snow groomer assembly includes a rotor and a plurality of teeth on the rotor extending axially and spaced circumferentially about the rotor to condition a snow pack when contacted. 
     One advantage of the present invention is that an improved snow groomer assembly is provided. Another advantage of the present invention is that the snow groomer assembly provides increased durability and thus prolongs the smoothness of the trail or slope. Yet another advantage of the present invention is that the snow groomer assembly allows ice to be turned back into snow on alpine slopes and snowmobile trails. Still another advantage of the present invention is that the snow groomer assembly acts on individual snow particles or grains and actually changes the structure of the snow pack. 
     Other objects, features and advantages of the present invention will be readily appreciated as the same becomes better understood after reading the subsequent description when taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an elevational view of a snow groomer assembly, according to the present invention, illustrated in operational relationship with a vehicle. 
     FIG. 2 is an enlarged elevational view of the snow groomer assembly of FIG.  1 . 
     FIG. 3 is a plan view of the snow groomer assembly of FIG.  1 . 
     FIG. 4 is a fragmentary elevational view of a portion of the snow groomer assembly of FIG.  1 . 
     FIG. 5 is an enlarged perspective view of a portion of the groomer drum assembly. 
     FIG. 6 is an enlarged side view of a portion of the drum assembly. 
     FIG. 7 is a section view taken along line  7 — 7  of FIG.  6 . 
     FIG. 8 is an elevational view of an alternative embodiment of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIG. 1, one embodiment of a snow groomer assembly  10 , according to the present invention, is illustrated in operational relationship with a vehicle  12 . The vehicle  12  is of a type known as a snow tractor, which is conventional and known in the art. It should be appreciated that the vehicle  12  can either push or pull the snow groomer assembly  10  or the snow groomer assembly  10  could be self-propelled. 
     Referring to FIGS. 1 through 3, the snow groomer assembly  10  includes a frame assembly, generally indicated at  14 . The frame assembly  14  includes a pair of side rails  16  extending longitudinally and spaced transversely. The frame assembly  14  also includes an end cross member  18  at both longitudinal ends of the side rails  16  and extending transversely therebetween. The frame assembly  14  includes a plurality of intermediate cross members  19  disposed longitudinally between the end cross members  18  and extending transversely between the side rails  16 . The side rails and cross members  18  and  19  are generally rectangular tubular members secured together by suitable means such as welding. 
     The snow groomer assembly  10  also includes a wheel assembly, generally indicated at  20 , operatively connected to the frame assembly  14  to allow the frame assembly  14  to be mobile such that it can be pushed or pulled by the vehicle  12 . The wheel assembly  20  includes a bearing block  22  having a bearing therein on each side rail  16  near a rearward end thereof. The bearing block  22  is attached to an underside of the side rail  16  by suitable means such fasteners  24 . The wheel assembly  20  also includes an axle or rotatable shaft  26  extending transversely between the side rails  16  and extending into the bearings of the bearing blocks  22  for rotation relative to the frame assembly  14 . The wheel assembly  20  includes at least one, preferably a plurality of wheels  28  connected to the axle  26  for rotation therewith. The wheels  28  are of the type having a wheel rim and tire. It should be appreciated that the bearing blocks  22 , axle  26  and wheels  28  are conventional and known in the art. It should also be appreciated that tracks could be used instead of the wheels  28 . 
     Referring to FIGS. 1 through 4, the snow groomer assembly  10  includes a rotor assembly, generally indicated at  30 , to condition or groom a snow pack  32  on a trail or slope. The rotor assembly  30  is disposed between the side rails  16  near a forward end thereof or opposite the end of the wheel assembly  20 . The rotor assembly  30  includes a support member  33  on the left side rail  16 . The support member  33  is generally V-shaped and extends downwardly from the left side rail  16 . The support member  33  is attached to the left side rail  16  by suitable means such as bolts in slotted holes to permit adjustment longitudinally and laterally of the left end of a rotor  37  to be described. A right side of the rotor  37  is supported by a belt case  60  to be described and is not adjustable. The rotor assembly  30  also includes a bearing block  34  having a bearing therein attached to left support member  33  and belt case  60  by suitable means such as fasteners  35 . The rotor assembly  30  includes a rotatable shaft  36  extending transversely between the side rails  16  and extending into the bearings of the bearing blocks  34  for rotation relative to the frame assembly  14 . It should be appreciated that the rotor assembly  30  is positioned vertically below the wheel assembly  20  a predetermined distance such as six inches for a six inch cut depth into the snow pack  32 . It should also be appreciated that this cut depth is variable by raising or lowering the front of frame assembly  14  by a lift arm  72  and a lift cylinder  76  to be described. 
     The rotor assembly  30  includes a rotor  37  disposed about the shaft  36 . The rotor  37  is a cylindrical tube or drum disposed about the shaft  36  and secured thereto by suitable means such as welding to allow rotation therewith. The rotor assembly  30  includes a plurality of teeth  38  disposed circumferentially about the rotor  37 . Preferably, the rotor  37  has approximately forty-eight (48) teeth  38  disposed circumferentially thereabout in a row and a plurality of rows spaced transversely along the rotor  37  to cut, reduce or condition the snow pack  32  when contacted. The teeth  38  are 0.5 inches in circumferential width and have a radial height of 0.75 inches with a bite per tooth of approximately 0.154 inches at 7 mph forward speed. The teeth  38  are formed by bars  39  extending axially and mounted to the rotor  37  by sliding the bars  39  through slots  40  in a plurality of, preferably nine, cutter retainer ribs that are formed by discs  41  extending radially and spaced axially along the rotor  37 . The discs  41  are secured to the rotor  37  by suitable means such as welding. 
     The snow groomer assembly  10  includes a drive assembly, generally indicated at  42 , for rotatably driving the rotor assembly  30 . The drive assembly  42  includes a prime mover  43  such as an internal combustion engine attached by suitable means such as bracing and fasteners (not shown) to the frame assembly  14 . The prime mover  43  has a rotatable shaft  44  extending transversely therefrom. The drive assembly  42  includes a fuel source  45  such as a diesel fuel tank and an electrical source  46  such as batteries attached by suitable means such as bracing and fasteners (not shown) to the frame assembly  14 . The fuel source  45  and electrical source  46  are connected by suitable means (not shown) to the prime mover  43 . It should be appreciated that the prime mover  43 , fuel source  45  and electrical source  46  are conventional and known in the art. 
     The drive assembly  42  also includes a torsional coupling  48  connecting the shaft  44  and a belt case input shaft  49 . An input drive sprocket  50  is keyed to the input shaft  49 . An output drive sprocket  52  is keyed to the rotor shaft  36 . The drive assembly  42  includes a belt  54  interconnecting the sprockets  50  and  52 . The drive assembly  42  rotates the rotor  37  at a predetermined speed such as V2 engine speed or 1100 rpm at rated engine speed. It should be appreciated that the prime mover  43  rotates the shaft  44 , torsional coupling  48 , sprocket  50  and belt  54 , in turn, rotating the sprocket  52 , shaft  36 , and rotor  37  and teeth  38  of the rotor assembly  30 . It should also be appreciated that the drive assembly  42  may have a plurality of sprockets and belts to rotate the rotor assembly  30 . 
     Alternatively, the rotor  37  could be driven hydraulically. In this case, the prime mover  43  drives a hydraulic pump (or pumps) (not shown) which, in turn, are coupled by flexible hydraulic lines (not shown) to a hydraulic motor (or motors) (not shown) which drive the rotor  37 . This structure, although less efficient provides the ability to run the rotor  37  in both directions (clockwise and counter clockwise). 
     The snow groomer assembly  10  also includes a belt case  60  to enclose the sprockets  50  and  52  and belt  54 . The belt case  60  is attached to the frame assembly  14  by suitable means such as fasteners (not shown). The snow groomer assembly  10  further includes a cover or fender  62  spaced from the rotor assembly  30 . The cover  62  is generally arcuate in shape and extends transversely between the side rails  16 . The cover  62  is supported at the rear by pins  64  and at the front by chains or cables  66 . 
     The snow groomer assembly  10  also includes a hitch assembly, generally indicated at  70 , pivotally connected to the frame assembly  14  to allow the snow groomer assembly  10  to be towed behind the vehicle  12  and to raise and lower the frame assembly  14 . The hitch assembly  70  consists of an A-frame shaped lift arm  72  pivotally connected to the side rails  16  of the frame assembly  14  by suitable means. The hitch assembly  70  includes a support plate  74  secured to the other end of the Jill arm  72  by suitable means such as welding. The hitch assembly  70  includes a hydraulic lift cylinder  76  pinned to the frame assembly  14  and the lift arm  72  for purposes of raising and lowering the frame assembly  14 . 
     The snow groomer assembly  10  includes a packing assembly, generally indicated at  80 , at a rearward end thereof for packing the conditioned snow. The packing assembly  80  includes a vibrator pan or plate  82  having upturned flanges  84  and connected to a post member  86 . The packing assembly  80  includes a pair of upper and lower support members  88  and  90  extending longitudinally and a pair of upper and lower cross members  92  and  94  extending transversely between the support members  88  and  90  and connected thereto by suitable means such as welding. The support members  88  and  90  and cross members  92  and  94  are tubular and generally rectangular in shape. The support members  88  and  90  are pivotally connected to the post member  80  and the frame assembly  14  by suitable means. The packing assembly  80  also includes two hydraulic cylinders  100  interconnecting the upper and lower support members  88  and  90  and pivotally connected thereto by suitable means to vary the down pressure of the plate  82  and to raise and lower the packing assembly  80 . It should be appreciated that the vibrator plate  82  acts as a skid plate and does the final compacting of the newly milled snow. 
     In operation, the snow groomer assembly  10  is connected to the vehicle  12  via the hitch assembly  70 . The prime mover  43  of the drive assembly  42  is started to rotate the rotor  37  of the rotor assembly  30 . The vehicle  12  pulls the snow groomer assembly  10  along a snow pack  32  at a predetermined speed such as seven to ten miles per hour as illustrated in FIG.  1 . The drive assembly  42  generally counter-rotates the rotor  37  with respect to the traveling direction of the snow groomer  10  as illustrated by the arrow in FIG. 4 (up-milling). As the rotor  37  rotates, the teeth  38  bite into the snow pack  32  and snow is captured in cavities between the teeth  38  and cover  62 . At the rear of the rotor  37  where the cover  62  stops, centrifugal force causes the finely milled snow to exit the rotor assembly  30  and forcefully impact the trail surface. The new finely milled snow is then compacted to a high density by the wheels  28  and vibrator pan  82 . This finely milled densely compacted snow  102  will consolidate into a very hard and durable snowmobile trail surface very quickly. For operation on alpine ski hills, the compaction would be reduced or eliminated resulting in the transmission of the ice chunks to fine snow ideal for skiing on. 
     FIGS. 5-7 better illustrate the bars  39  as they are supported within the slots  40  in the ribs or discs  41 . Each bar  39  includes a pin, bolt, or other retainer member  104  extending through each of its ends. The retainer members  104  are long enough to prevent the bar  39  from being slid axially out of the slots  40 . The retainer members  104  may alternatively be substantially anywhere along the lengths of the bars  39  to limit axial movement of the bars  39  in the slots  40 . 
     The bars  39  are configured to have cross-sectional areas and dimensions that are smaller than the slots  40  in which they are supported. This permits the bars  39  to rattle within the slots  40 . The rattling and resultant vibration of the bars  39  facilitates the reduction and pulverization of the hard-packed snow and ice into finer particles that are more suitable for the landscape (e.g. ski hills or snowmobile trails) over which the groomer  10  is traveling. The rattling and vibration of the bars  39  also prevents the build-up of snow and ice between the bars  39  and rotor  37 , as well as between individual bars  39 . 
     The illustrated construction includes bars  39  having lengths substantially equal to the longitudinal extent of the rotor  37 . The illustrated slots  40  on the discs  41  are aligned with the slots  40  of all other discs  41 . Alternatively, some slots  40  may be aligned with some, but not all slots  40  of the other discs  41 . In this regard, groups of aligned slots  40  may support shorter bars  39 , and the bars  39  may be staggered with respect to each other. 
     FIG. 8 illustrates an alternative embodiment of the invention. In this embodiment the hitch assembly  70  also supports an operator enclosure  106  and is secured to a more centrally located area of the vehicle  12 . The lift cylinder  76  is also reoriented to a more vertical position to raise and lower the rotor assembly  30 , thereby adjusting the cut depth of the snow groomer  10 . The positions of the packing assembly  80  and wheel assembly  20  have also been switched. An actuator  108  is employed to raise and lower the wheel assembly  20 . During snow grooming operations, the wheel assembly  20  is moved to a raised position and the snow groomer  10  is supported by packing assembly  80 . When an obstacle such as a road or other non-snow-covered surface is approached, the wheel assembly  20  is lowered, thereby raising the rotor assembly  30  and packing assembly  80  to a non-grooming position. When engaged with a snow-covered surface, the packing assembly  80  operates in the same manner as the previous embodiment. The remaining components including the frame assembly  14 , prime mover  42 , fuel source  45 , and rotor assembly  30  operate and interact in substantially the same manner as described for the previous embodiment. 
     The present invention has been described in an illustrative manner. It is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. 
     Many modifications and variations of the present invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the present invention may be practiced other than as specifically described.