Abstract:
A method of collecting, preserving and repositioning snow on a ski slope whereby the slope may be placed in condition for skiing in the fall prior to the time of sufficient fall of natural snow or the arrival of freezing conditions necessary for the production of man-made snow.

Description:
This is a continuation of co-pending application Ser. No. 886,444 now abandoned, filed on July 17, 1986 and which, in turn, is a continuation of Ser. No. 776,855 filed Sept. 18, 1985, now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     Skiing on ski slopes or trails terminates in the late winter and early spring with the melting of the snow. The slopes and trails become bare over the summer months. Skiing normally resumes in the fall or early winter when sufficient snow has fallen to provide adequate snow cover on the slopes and trails. 
     In a few instances, early fall skiing has been achieved by the spreading of man-made snow but the success of this process is dependent on the arrival of nights with below freezing temperatures. 
     SUMMARY OF THE PRESENT INVENTION 
     The present invention is to a method whereby any selected ski slope or trail may be placed in skiing condition earlier in the fall than would normally be the case. Hereinafter when the term ski slope is used it will also include a ski trail. The method will be most commonly used on ski slopes. 
     The method comprises the steps of closing the selected slope in the late winter or early spring while there is still adequate snow cover thereon. The snow is then concentrated by hand or machine into a series of piles over the entire length of the slope. These piles will be high in the center and tapering downwardly to the surrounding ground. The piles preferably will be circular. The spacing of the piles will be determined by the depth and location of the snow available. 
     The piles of snow are then covered with sheets of insulating material of such character that a major volume of the piled snow will be preserved over the summer and early fall months. When the average ambient temperature has dropped in the fall to a degree at which the snow will not melt away, the piles will be uncovered and the snow redistributed, by hand and/or machine over the selected areas of the slope. The depth of the redistributed snow now covering the selected slope area will be adequate for immediate skiing and will last until the arrival of natural snow. Should the arrival of natural snow be delayed, the snow base can be augmented by the application of man-made snow at the necessary locations after nighttime freezing conditions have arrived in the fall. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a plan view of a snow covered ski slope. 
     FIG. 2 is a vertical section on the line 2--2 of FIG. 1. 
     FIG. 3 is a section on the line 3--3 of FIG. 2. 
     FIG. 4 is a plan view of the ski slope of FIG. 1 with the snow thereon pushed into a plurality of piles. 
     FIG. 5 is a vertical section on the line 5--5 of FIG. 4. 
     FIG. 6 is a section on the line 6--6 of FIG. 5. 
     FIG. 7 is a plan view of the ski slope of FIGS. 1 and 4 with the piled snow of FIGS. 4, 5 and 6 redistributed on the slope. 
     FIG. 8 is a vertical section on the line 8--8 of FIG. 7. 
     FIG. 9 is a section on the line 9--9 of FIG. 8. 
     FIG. 10 is a view similar to FIG. 9 but showing the snow covering a greater area. 
     FIG. 11 is an enlarged view illustrating a snow pile to which man-made snow has been added. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 is intended to represent any ski slope 2 which is covered with snow 4. For help in explanation of the invention, the snow covered area of the slope is shown as having top, side and bottom boundaries indicated at 6, 8, 10 and 12. 
     FIG. 2 is a vertical section taken on the line 2--2 of FIG. 1 showing the ground 14 with the snow 4 covering the sloping surface 2. The upper limit of the snow with which we are concerned is at 6 and the bottom limit at 8. FIG. 3 is a section taken on the line 3--3 of FIG. 2. 
     It is to be understood that the representation of FIGS. 1, 2 and 3 is intended to include any ski slope having thereon snow (natural, natural and man-made or man-made) toward the end of the skiing season when the operator elects to close the slope. 
     It will be appreciated that the depth and disposition of the snow at the time the slope is closed may vary greatly depending upon the extent of the snow fall over the past winter and the configuration of the ground surface. 
     The snow on the slope is pushed, preferably by machines, into a plurality of piles of snow indicated at 16 in FIGS. 4, 5 and 6. The location of the piles of snow on the slope will be dictated by the configuration of the slope, the depth of the snow and the judgment of the operator. The piles are made as high as possible, preferably generally circular in plan and are then covered with sheets of insulating material 18 of such properties as to be capable of preserving a major portion of the snow over the summer and early fall. 
     In places where the snow is deep, it may be pushed into suitably sized piles without using all of the snow adjacently available. Where the snow cover is thin, it may be necessary to use all of the snow at that location to produce a large enough pile to survive the summer. In all cases the object is to preserve enough snow by the piling procedure plus the insulating covering to have enough snow available in the fall which when spread on the slope will create adequate skiing conditions. Preferably the area of the collected snow pile should be small in relation to the area from which the snow was collected. In other words, a high pile on a small area is preferably to a lower pile in a larger area because the percentage loss from melting is approximately inversely proportional to the height of the pile. Snow can readily be piled by machine to a height of 20 feet or more at the center and sloping to the sides in a circular pattern. A pile of snow of this character covered with suitable insulating material will lose no more than 20 to 25% of its volume over the summer. Thus for example if there was an average of two feet of snow on the slope when the piling commenced and all of it was pushed into the piles, enough snow would remain by fall to cover the slope to an average depth more or less of one and one-half feet, adequate for immediate skiing. 
     FIGS. 7, 8 and 9 are illustrative of the condition of the slope following distribution of the snow in the fall from the piles 16 shown in FIGS. 4, 5 and 6. In FIG. 7, the lines 20 and 22 suggest the somewhat reduced width of the slope if the original depth is provided whereas FIG. 9 suggests a width of slope corresponding to boundaries 8 and 10 of FIGS. 1 and 3 but with a reduced depth determined by the extent of the melting. 
     It has been found desirable and practical in some situations to increase the volume of the preserved pile of snow by removing the cover 18, adding man-made snow and recovering the pile as shown in FIG. 11. This procedure would be used when the residual layer of snow available in the spring was inadequate for producing the depth initially wanted in the fall. The addition of man-made snow can be made whenever the temperature falls below freezing which condition usually begins early in the fall. Repeated additions of man-made snow will create a pile sufficient when spread to provide skiing conditions on the selected area. FIG. 11 suggests the condition existing after man-made snow 24 has been added to the initial pile of snow 16 and the covering 28 replaced. 
     The process of accumulating the residual snow in piles in the spring and distributing it in the fall will preferably proceed from the top to the bottom of the slope as the snow movement is aided by gravity but this process may be varied under the judgment of the machine operator. 
     Insulating covering adequate to preserve snow over the summer is available in the open market. One such material comprises two layers of aluminum foil spaced about 1/4 inch between which are two layers of polyethylene bubbles. These circular flattened bubbles, about 3/8 inch in diameter are arranged so that each bubble is surrounded by six other bubbles, all bonded to themselves and to the covering layers of aluminum foil. This construction forms a strong sheet having the capability of substantially limiting passage of the sun&#39;s radiant heat and the heat of the ambient air to the snow thereunder. The sheet may be further strengthened by a coating of clear polyethylene to both exterior sides. This sheet is light, flexible and durable and may be readily rolled on and off each pile of snow. 
     The sheets must be firmly anchored to the ground to prevent the sheets from being dislodged by the wind and also to prevent the entrance of warm air under the sheets which would cause excessive melting of the covered snow. The sheets may be anchored for example by placing weights on the edge areas 26 or in any other manner available. The securing means must be readily removable so that the sheets can be rolled off the piles and saved for use the following year. 
     In the drawings, it will be understood that the thickness of the sheets in relation to the size of the piles of snow has necessarily been exaggerated for purpose of illustration. 
     It is intended to cover all changes and modifications of the example of the invention herein chosen for purposes of the disclosure which do not constitute departures from the spirit and the scope of the invention.