Patent Publication Number: US-2002011012-A1

Title: Snow surface grooming apparatus

Description:
[0001] The present invention claims the priority date of a prior filed provisional patent application having Ser. No. 60/184458 and an official filing date of Feb. 22, 2000 and which discloses substantially the same material as described herein. 
    
    
     
       BACKGROUND OF THE INVENTION  
       [0002] 1. Field of the Invention  
       [0003] This invention relates generally to devices for grooming the surface of a snow field and more particularly to such an apparatus with hydraulic actuation for positioning the vertical attitude of a sled, a drawing yolk and a set of wheels.  
       [0004] 2. Description of Related Art  
       [0005] The following art defines the present state of this field:  
       [0006] Kober, U.S. Pat. No. 3,043,034 describes a leveler comprising a hitch embodying a pair of side elements connected together, a pair of angularly arranged braces having their front ends affixed to said side elements, a front runner section providing a front tuck comprising a pair of horizontally disposed short angle irons having upstanding ears thereon pivotally connected to the rear ends of said braces, trunnions, extending outwardly from said angle irons, a pair of front runners having blocks affixed thereto and bearings on said blocks swivelly receiving said trunnions; a pair of horizontally disposed spaced parallel bars extending between said pair of angle irons and secured thereto, a smoothing blade mounted, below said bars and including an inclined portion and a lower horizontally disposed portion; a turntable mounted on said bars intermediate the ends thereof, trunnions affixed to said turntable, the rear portions of said side elements being connected to said last named trunnions, a main frame including a pair of similar side members, and said side members including spaced parallel forwardly disposed front first portions connected to said turntable, second portions arranged angularly with respect to said first portions, spaced parallel third portions arranged rearwardly of said second portions, angularly arranged fourth portions disposed rearwardly of said third portions, spaced parallel apertured lugs extending upwardly from the first portions of said frame, bearing elements on the inner surfaces of the second portions of the frame, a cross element pivotally connected to said bearing elements, an outer tubular member arranged at right angles with respect to said cross element and affixed thereto, and said tubular member adapted to selectively extend between the first portions of the frame, pins adapted to be selectively arranged above said outer tubular member and said last named pins adapted to engage said lugs, an inner tubular member slidably arranged in said outer tubular member, hand pieces connected to the outer end of said inner tubular member, a cross brace extending between the side elements of said hitch for selective engagement by the inner tubular member; a rear runner section defining a back truck comprising a pair of spaced parallel horizontally disposed back runners having blocks thereon with bearings affixed to said last named blocks, angle irons having trunnions swivelly engaging said last named bearings, a pair of spaced parallel horizontally disposed bars extending between said last named angle irons and secured thereto, a smoothing blade mounted between said last named angle irons and arranged below the last named bars, a rear turntable connected to the fourth portions of the main frame and also operatively connected to the rear runner section, a lock pin for said rear turntable, cables engaging said main frame and connected to said front and rear runner sections, first, second and third horizontally disposed spaced parallel tubular support members extending between the third portions of the frame and secured thereto, support pieces affixed to said first support member brackets affixed to said support pieces, pulleys supported by said brackets; vertically disposed uprights affixed to said second support member, yokes affixed to said uprights and said yokes including upper and lower pieces interconnected by vertically disposed element, cradles pivotally connected to said uprights, support pieces affixed to said second support member and extending upwardly therefrom, brackets connected to said last named support pieces and said last named brackets having pulleys journaled thereon, a counterweight adapted to selectively engage said cradles, lines connected to said counterweight and engaging the last named pulleys, a pair of spaced parallel beams having said lines connected thereto, a scraper blade affixed to said beams, guide members mounted at the ends of the scraper blade, bearing members affixed to said scraper blade and said bearing members having trunnions thereon, a pair of spaced parallel side pieces affixed to the inner surfaces of the third portions of the frame and said side pieces having said last named trunnions pivotally connected thereto, base pieces connected to the lower surfaces of the side pieces, rods connected to said cradles, bearing units operatively connected to said rods and said bearing units being pivotally connected to said yokes, coil spring circumposed on said rods, hydraulic cylinders connected to said second support member, piston rods connected to said cylinders, bell cranks pivotally connected to the fourth portions of the frame, and said bell cranks being connected to said piston rods, and wheels connected to said bell cranks.  
       [0007] White, U.S. Pat. No. 3,739,859 describes a lightweight snow leveler for redefining snowmobile trails incorporating an elongated rectangular frame having front and rear traveling skis. The frame mounts a leading series of snow pulverizing discs and trailing cooperating sets of snow-shifting blades alternately rolling the pulverized snow inward, then outward and finally inward so as to provide a soft redefined trail.  
       [0008] Pease, U.S. Pat. No. 3,779,319 describes a trailer for breaking and pulverizing crusty and/or icy snow cover on a ski slop comprising a frame provided with wheels by means of which it may be transported over open roads and/or bare ground to a ski slope and skis for traversing the slope. The trailer frame has on it a motor-driven drum to which are attached a plurality of chain flails having at their distal ends beaker elements for cutting through the hard cover, and there are adjustable mounting members connecting the skis to the frame so as to enable raising and lowering the frame and hence the drum relative to the skis so that on the one hand the drum may be supported above and spaced from the snow cover to permit the flails to be turned at a rapid rate about the axis of the cylinder and to cause the breaker elements at their ends to break through the crust and on the other hand may be lowered into substantial engagement with the cover to cause the flails to become traction elements between the drum and the cover.  
       [0009] Maxey, U.S. Pat. No. 4,056,328 describes an apparatus for grooming snowmobile trails towed by a dirigible tracked vehicle and including a generally horizontal main frame, a gooseneck hitch supporting the forward end of the frame in towing engagement with the tracked vehicle, a packing roller supporting the rear end of the frame which serves to pack the snow being groomed, a moldboard scraper mounted between the packing roller and the gooseneck hitch which serves to scrape and level the snow being groomed, and a cutting blade assembly mounted forwardly of the moldboard scraper cuts, breaks and moves snow to fill in grooves and level ridges. A floating pan secured to the rear end of the main frame smoothes the snow following packing by the roller. The snow breaking and cutting blade assembly includes a pair of opposed, spaced-apart cutting blades pivotally secured to the frame and inclined inwardly and rearwardly, and a central V-shaped cutting blade pivotally secured to the frame with the apex thereof directed forwardly. The inner free ends of the inclined blades and the apex of the V-shaped blade are coordinated for raising and lowering to cause the apex of the V-shaped blade to swing oppositely to the free ends of the inclined blades for purposes of controlling the flow of snow through the frame to the moldboard scraper and packing roller.  
       [0010] Olson, U.S. Pat. No. 4,244,662 describes a snow grooming device for leveling a snowmobile trail comprising a frame having retractable wheels for transporting the snow grooming device and a set of angled blades which direct the snow back and forth across the trail to a leveler bar that directs the snow to a compacter attachment.  
       [0011] Niemela, U.S. Pat. No. 4,520,582 describes an apparatus for making ski trails which is towed and comprises a drag having a cutter unit and a snow crushing unit mounted behind the cutter unit on the drag. The units have radial blades and rotate about an axis transverse to the direction of travel of the apparatus. The cutter unit derives its rotary motion from the tamped track of the snow and is connected by a transmission to the crushing unit whereby the latter derives its rotary motion from the cutter unit.  
       [0012] Scheibel et al., U.S. Pat. No. 4,523,398 describes an apparatus for forming cross country ski tracks in a snow covered surface having a trailer frame adapted to be connected to the rear end of a vehicle. A lifting frame is connected to the trailer frame for pivotal movement about a first horizontal axis. The lifting frame has a pair of parallel guide members extending longitudinally from the trailer frame to a transversally extending crossbar. The guide members are arranged symmetrically on opposite sides of a central axis common to the lifting frame, the trailer frame, and the vehicle. At least one cross country ski track forming device is connected to the crossbar for pivotal movement about a second horizontal axis. A positioning device is connected between the trailer frame and the lifting frame. The positioning device pivotally manipulates the lifting frame about the first horizontal axis between an operative position at which the track forming device extends rearwardly from the trailer frame to contact and impress tracks in the snow covered surface, and an inoperative position at which the track forming device is elevated from the snow covered surface and is folded over the trailer frame.  
       [0013] Wieland et al., U.S. Pat. No. 4,559,725 describes a rotary tiller for maintaining cross country ski trails having a rotary shaft with at least one array of radially extending first cutters flanked by laterally adjacent arrays of radially extending second cutters. The radial lengths of the first cutters are greater than the radial lengths of the second cutters. The first cutters are arranged to till a center ski track and the second cutters are arranged to till pole tracks on either side of the ski track, with the ski tracks having a tilled depth greater than that of the pole tracks.  
       [0014] Emanuel, U.S. Pat. No. D393,233 describes a combined sled and wagon.  
       [0015] Beeley, WO81/03353 describes a vehicle drawn snow tiller for loosening, cutting, grinding, packing and leveling a wide path of snow for improved, more enjoyable skiing. The tiller comprises an elongated rotary snow cutter assembly with radially projecting snow cutting blades distributed over the length and about the circumference of a cutter tube directly powered by reversible hydraulic motors, one mounted upon each of its ends. The snow is cut, selectably, in or away from the direction of travel of the tiller over the snow. An elongate apron disposed over the cutter assembly collects and directs the loose cut snow onto the surface behind the cutter assembly, where it is compacted by the apron and finally leveled and smoothed by a horizontal grooming bar on the trailing edge of the apron. An elongate snow splitting baffle may be disposed above the cutter to deflect a portion of the cut snow forward to fall again into the path of the reversely rotating cutter for additional cutting and grinding. The cutter assembly may comprise two segments and flexibly coupled at the center of the tiller to facilitate fabrication and assembly of the tiller, and to alleviate the effects of shock to the cutter. Each segment may be similarly coupled to one of the motors.  
       [0016] Sinykin, WO98/52658 describes a snow tiller for ski slopes having rotating cutter bars with outstanding teeth. The cutter bars are each installed beneath a cover which directs the snow rearwardly to a smoothing comb. Each cover is adjustable in geometry to provide either greater of less angle of entry of the snow beneath the snow comb, and the change of angle is coordinated with changes in depth of snow cutting by the cutter bar teeth. A double acting hydraulic cylinder and ram assemble links cutter bar mounting frames and is used to control the longitudinal angles of the cutter bars upon the snow.  
       [0017] The prior art teaches the use of towed vehicles for grooming the surface of a snow field, but does not teach such an apparatus with vertically positionable blades for selecting a depth of cut in the snow within a path of travel. The present invention fulfills these needs and provides further related advantages as described in the following summary.  
       SUMMARY OF THE INVENTION  
       [0018] The present invention teaches certain benefits in construction and use which give rise to the objectives described below.  
       [0019] A snow grooming apparatus is adapted for being drawn by a towing vehicle on a snow surface such as a ski slope. A drawing yolk engages the towing vehicle and pivots on a main chassis of the apparatus. The main chassis rides on a pair of spaced apart runners and supports plural snow shearing blades which are angled for directing snow laterally with respect to the center of the apparatus. An hydraulic actuating system is adapted for vertically positioning a ski centered with respect to the runners and forward of the center of mass of the main chassis. Thus, when this ski is extended downwardly, the main chassis and the snow shearing blades are raised. A pair of wheels of a secondary chassis are movable such that the main chassis may be supported above a snow or road surface between the pair of wheels and the hitching means. Alternately, the pair of wheels may be drawn up, above the surface with the main chassis supported on its runners when the ski is raised. The apparatus, when running on a snow field or along a trail, smoothes the snow surface. The blades shear off the peaks and move this now loose snow laterally back and forth between the runners so as to fill-in the valleys and thus leave a relatively smooth surface. The rear end of the chassis is weighted placed in contact with the surface to smooth the trail.  
       [0020] A primary objective of the present invention is to provide an apparatus and method of use of such apparatus that provides advantages not taught by the prior art.  
       [0021] A further primary objective is to provide such an apparatus having a forwardly positioned vertically adjustable ski, capable of raising the forward portion of the apparatus to change the relationship between a plow blade and the surface of a snow field or trail.  
       [0022] Another objective is to provide such an invention capable of running on snow or over a hard surface.  
       [0023] A further objective is to provide such an invention capable of smoothing the surface of a snow field over which it is drawn.  
       [0024] A still further objective is to provide such an invention capable of remote control of the vertical positions of its several operating parts. 
     
    
    
     [0025] Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.  
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0026] The accompanying drawings illustrate the present invention. In such drawings:  
     [0027]FIG. 1 is a partial rear perspective view of the preferred embodiment of the invention apparatus;  
     [0028]FIG. 2 is a partial front perspective view thereof.  
     [0029] FIGS.  3 - 5  are side elevational views thereof;  
     [0030] FIGS.  6 - 8  are partial side elevational views thereof particularly showing a ski in fully retracted (FIG. 6), partially extended (FIG. 7) and fully extended (FIG. 8) positions;  
     [0031]FIG. 9 is an illustrative schematic diagram of a top plan view showing the manner in which snow is moved, see arrows, through the apparatus.  
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
     [0032] The above described drawing figures illustrate the invention in at least one of its preferred embodiments, which is further defined in detail in the following description.  
     [0033] The present invention is a snow grooming apparatus adapted for being drawn by a towing vehicle along a line of travel over a surface  8 . It&#39;s primary use is found as a grooming device for snowmobile trails where snowmobile tracks and ski ruts in the snow surface  8  must be smoothed and groomed. However, the invention is highly useful for smoothing ski slopes and similar surfaces as well.  
     [0034] The invention includes a hitching means  10 , whish is a Y-shaped yoke adapted for engaging a towing vehicle  20 , such as a truck or tracked vehicle (not part of the invention). As shown in FIG. 2, the hitching means  10  generally comprises a standard coupling ring  12  positioned at the end of the Y-shaped yoke or hitch assembly  14  pivotally joined with a main chassis  30  of the apparatus. The pivot pins are shown at  16 . The main chassis  30  provides opposing and spaced apart runners  32  directed along the line of travel and adapted by their structural integrity and physical position for supporting the main chassis  30  as it travels on the snow surface  8 . The main chassis  30  further provides at least one pair of snow shearing blades  34  and  36 , as best seen in FIG. 9, and these are angled for directing snow laterally within the apparatus. Preferably, the snow shearing blades comprises a forward and rearward pair of these snow shearing blades and a further pair of snow shearing blades  36  engaged with the main chassis  30  and positioned between the blades  34  as shown in FIG. 9. Notice that as snow is moved laterally it is generally confined to the space between the runners  32 . Thus, loose snow that is sheared from snow mounds is moved about to fill ruts caused by snowmobiles, skis, snowboards, etc.  
     [0035] A secondary chassis  40  is pivotally engaged with and extends rearwardly of the main chassis  30 , and terminates with a rolling support means; preferably a pair of wheels  42  positioned for trailing the main chassis  30 . Alternately one or more than two wheels may be employed as will be apparent to those of skill in the art. The pivotal axis  44  is shown in FIG. 1. Various portions of a hydraulic actuating means shown, in part, by numerals  50  and  52  in the figures, is adapted for vertically positioning the main chassis  30  above the operating surface  8 . As shown in FIGS. 5 and 6, vertical positioning of the chassis  30  is achieved through hydraulic actuating means portions  50  and  52  when the wheels  42  are in contact with the surface  8 . The hydraulic actuating means portion  50  is able to move the secondary chassis  40  independently, so as to position the pair of wheels  42  in touch with the surface  8  (FIG. 5) or, alternately, in a retracted position (FIG. 4). The snow shearing blades  34  and  36 , as is illustrated in FIGS.  6 - 8  are vertically positionable relative to the surface  8  through the use of portion  54  which drives a ski  38  vertically. Ski  38 , when lowered, is able to support the front portion of the main chassis  30 . FIGS.  3 - 5  show the various positions that the main chassis  30  may acquire through the use of the hydraulic actuating means portions  50  and  52  such that the main chassis  30  may be supported above the surface  8  between the pair of wheels  42  and the hitching means  10 . FIG. 6 shows how the leading end of the main chassis  30  may be moved vertically via portion  52 . The snow shearing blades  34  and  36  may be selectively vertically adjusted using portion  54  as shown in FIGS. 7 and 8 by vertically and selectively positioning ski  38 . Hitching means  10  may be adjusted to move freely about pivot pins  16  or, by engaging hydraulic actuating means  52 , hitching means  10  may be rigidly adjusted to lift the front end of the main chassis  30  so as to transfer a selected portion of the main chassis  30  weight to the tower vehicle  20 .  
     [0036] A storage box  60  is mounted rearwardly on the main chassis as shown in FIG. 1. This box  60  provides a flat undersurface  62  and, with tools and other supplies being carried within, and with the weight of the secondary chassis  40 , the rear portion of the main chassis  30  provides a smooth and downwardly pressing force for grooming and smoothing the snow surface.  
     [0037] As previously described, the apparatus, when running on its runners  32  in a snow field or along a trail as depicted in FIGS. 4 and 8, encounters peaks and valleys, vis-à-vis, the level of the snow surface  8 . The blades  34  and  36  shear off the peaks and move this, now loose, snow laterally back and forth between the runners  32  so as to fill-in the valleys and thus leave a relatively smooth surface. The bottom surface of the storage box  60  tends to smooth this surface further and compact it so that it is an improved snow surface for receiving recreational snow equipment such as snowmobiles, skies and snowboards. The lateral motions provided to the loose snow sheared by the various blades  34 ,  36  tends to break it down into smaller pieces and spread it out over the traversed surface  8 .  
     [0038] Clearly, the details of operation of the hydraulic actuation means  50 ,  52  and  54  has not been described here. However, the actuators are common linear hydraulic cylinders joined by hydraulic lines in a well known manner easily enabled by one of skill in the art. Remote actuation from a pulling truck or track vehicle is also well known. It is believed that it will be quite clear to those of skill in the art as to how to make and use the invention from the above description taken with the several illustrations. To assure that this is so, the patent document of Olson, U.S. Pat. No. 4,244,662 is hereby incorporated into this disclosure by reference.  
     [0039] While the invention has been described with reference to at least one preferred embodiment, it is to be clearly understood by those skilled in the art that the invention is not limited thereto. Rather, the scope of the invention is to be interpreted only in conjunction with the appended claims.