JPS61222471A - Method for fastening day bringing ski slope to ski enabling condition in autumn and snow holding apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application] The present invention provides an appropriate base snow layer for receiving natural snow in the autumn season or for receiving artificial snow in the autumn season.
The present invention relates to a device for sufficiently retaining snow on a ski slope during the period between the last snowfall in the spring and the first snow in the fall, and a method for hastening the day when the ski slope reaches skiable conditions in the fall.

[Background of the invention]

Downhill or flat skiing is a worldwide sport. At the end of the spring ski season, the snow gradually melts, exposing the ground and exposing it to high temperatures during the summer. In the fall, the ground gradually cools as temperatures drop, but the ground temperature is rarely low enough to melt the initial snowfall.

Therefore, several snowfalls over a period of time are required before the snow accumulates to provide suitable conditions for skiing.

Attempts were made to quickly create root snow using artificial snow, but
This is very expensive, and it is not used to create root snow because it only serves as a substitute. Artificial snow generally does not fall on slopes or flat areas until natural ground snow has formed and temperatures are well below freezing.

To the best of the knowledge of the inventors, snow that accumulates in winter is sufficiently thick to constitute a suitable base snow to support the first snowfall of late fall, or artificial snow immediately formed when temperatures are sufficiently low. No attempt has been made to preserve the snow layer throughout the summer.

Therefore, good skiing conditions can only be exploited after natural snow has fallen to completely cover the slope or level ground, or by a combination of natural snow and artificial snow applied in areas without natural snow.

[Summary of the invention]

In the present invention, in late autumn and during the first snowfall of winter, fallen snow can be retained and conditions on slopes and flat areas suitable for skiing can be made earlier than if the root snow had not been preserved. It is proposed to cover the entire slope or level area, or any desired portion of the slope or level area, with a removable sheet of insulation having such properties as to limit the melting of snow during spring, summer and autumn. .

The present invention, in combination with currently known insulating sheets and flexible sheet-like support structures, insulates snow from the summer heat and allows snow to accumulate in the fall and winter. The aim is to use other insulating materials that may appear in the future as long as they can be preserved as such.

Slopes and mechanisms on level ground can be provided to quickly and easily perform the task of laying the insulation sheet on the snow in the spring and removing the insulation sheet from the snow in the fall. Alternatively, the insulation sheets can be installed and removed manually. The dimensions of the insulation sheet can be any desired. Insulation sheets can be shaped into horizontal or vertical rectangles and rolled up at the bottom or side of the slope if it gets in the way during the winter.

In one embodiment, the means for winding the insulation sheet comprises:
It can be attached to or pulled by a truck or tractor that moves from one sheet of insulation to the next along a slope. The sheets of insulation, which are stored in rolls, can be manually spread across the slope in the spring and adjusted to fit adjacent sheets of insulation to completely cover the snow.

Alternatively, the sheet of insulation can be in a continuous manner extending from the top to the bottom of the ski slope. A toothed track is laid on one or both sides of the slope, connected by overhead means, and in the spring the insulation sheet is spread over the snow, and in the fall the insulation sheet is rolled up from the snow. A machine that can be removed can be placed on top of the toothed track.

Insulating sheets are placed directly on the snowy soil in a manner that has been recognized as suitable for preserving soil over the summer. If a particularly high level of insulation is required or desired, spacers made of foam rubber strips can be used at intervals of approximately 10-odd meters (approximately a few inches) above the snow. An insulation sheet can be laid down. In order to keep the insulation sheets clear of the snow, the strips can be manually placed close enough together to provide the desired spacing.

It is desirable or necessary to provide a path for people and animals on a certain slope or flat area. In that case, it is clear that the path will not be covered with an insulating sheet in the summer, so when the insulating sheet is removed in the fall, there will be no snow in that area. . Therefore, in the fall, the appropriate amount of snow is distributed to the parts of the road where there is no snow, and the appropriate amount of snow is distributed to cover the parts of the road continuously with snow, as if the snow had not disappeared in the summer. This shortcoming is overcome by creating a path close to where the snow is deep enough to preserve it.

Provided that the snow to be covered with insulation sheets is deep enough in the spring, the amount of insulation sheets used can be saved by making the path more or less as wide as the area to be covered. Then, by mechanically distributing some of the large amount of snow that has been stored in the fall to snow-free areas,
A desired continuous root snow layer can be provided.

You can also see that it is possible to store snow by covering it with an insulating sheet next to the ski slope or Heiju Ski Resort, and then use a bulldozer to spread the snow over the ski resort in the fall. Dew.

Accordingly, in another embodiment of the invention, snow is piled up in a series of piles along the length of the slope, either manually or mechanically. These snow mounds are high in the center and slope downward to the surrounding ground. Make the snow pile as circular as possible. The spacing of snow piles is determined by the depth of snow available and the location of the snow.

The snow pile is covered with a sheet of insulating material of such a nature that the bulk of the snow mass is preserved during the summer and early fall periods.

In the fall, when the average temperature drops to a level where thunderstorms persist, the snow mound cover is removed and the snow is distributed manually or mechanically to selected areas of the slope. The snow depth placed on that selected area of the slope remains at a suitable depth for skiing until the first snow falls. If snowfall is delayed, artificial snow can be deposited where needed to thicken the snow layer when nighttime temperatures drop below freezing.

As used herein, the term snow includes any material present on a covered slope in the form of frozen water, such as ice, sleet, or slush.

From the above explanation, the object of the present invention is to
consists in covering snow or snow piles on selected slopes or level ground without imposing any restrictions on the dimensions, the nature of the insulation provided by the insulation sheet, the manner or means of covering the insulation sheet; You will understand. The insulation sheets can also be rigid structures that cannot be rolled up, but can be stacked when not in use.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the drawings.

Reference is made to FIG. 1 in which a vertical section of land representing a ski slope or flat ski area is designated by reference numeral 2. Hereinafter, when the term slope is used, the term is intended to include ski slopes that are generally flat and narrower than ski slopes.

The invention is applicable to both slopes and flat terrain.

On the surface 4 of the slope there is a layer 6 of snow. This layer of snow is the layer of snow that remains when this slope is closed as a ski resort in the spring.

#1 Almost every ski area has several slopes, so if you close one slope that wants to preserve snow in the summer, you won't be able to ski in the spring on other slopes that don't preserve snow. There is no problem in continuing. therefore,
Slopes that should be closed can be closed when snow remains at an appropriate depth, even in the summer, if properly thermally insulated, the snow will not melt and will be preserved.

As the fall progresses, enough residual snow remains on the slope to keep the ground below cool and leave a root layer that can hold the snow that fell earlier.

Therefore, the snow remaining on the closed slope is preserved during the summer by covering the snow with the insulation sheet 8. The radiant heat of the sun or the heat of the surrounding air is used so that, even after the remaining snow melts during the hot summer months, there is always enough snow left in the fall to provide a starting layer for winter's natural snowfall or artificial snowbanks. There are many insulating materials that have the ability to block out residual snow.

In one embodiment of the present invention, the insulating covering sheet can be in the form of a plurality of sheets 10 that can be laid down manually or mechanically over the remaining snow in the spring, and removed in the same way in the fall. A plurality of sheets 10 are shown in an enlarged cross-sectional view in FIG. The upper and lower surfaces of this insulating sheet 10 are covered with aluminum foil for strength. sawdust, glass fiber,
Thermal insulation material 14, such as rock wool, small sheets of insulation board, or other thermal insulation materials currently available or that will become available in the future, is prevented from shifting within the sheet, as indicated by reference numeral 12. Insulating material sheet 10
is quilted.

To add strength, the outer surface of the aluminum foil can be covered with sheets of canvas or other fabric, sheets of plastic, foam, or other materials that provide thermal insulation, reinforcement, and water resistance. To achieve the best results, some experimentation may be required to relate the particular insulation coating to the snow depth and average summer temperature where the slope is located.

An example of a means for moving the insulation sheet off the ramp is shown in FIGS. 3, 4, and 5. The base 16 supporting the winding device is removed from the truck at the end of the sheet 10 and can be placed on the ground or slid over the ground to the appropriate location. It can be used or loaded onto a truck, tractor, or other transport vehicle. An end of the sheet 1o is fixed to a shaft 22. When this shaft is rotated through a gear mechanism, the sheet 10 is wound around the shaft 22 (fourth
(Fig. 5). The rolled sheet is then removed from the shaft 22 by removing the bearing 18 and its support.
During the winter, you can leave it on the ground nearby. When the remaining snow is covered again with the sheet 10 in the spring, the sheet can be manually rolled #1 across the slope and the condition shown in FIGS. 1 and 3 can be resumed.

Another embodiment of the invention is shown in FIGS. 6-9.

In FIG. 6, a sloping terrain 4o is covered with an insulating material sheet 42 during the summer. Next winter's snow 44 is piled up on the sheet. To preserve the snow for the next summer, the snow 44 is covered with an insulating sheet 46 in the spring.

The combined thermal insulation effect of the lower insulation sheet 42 and the upper insulation sheet 46 of the snow 44 allows the snow to be removed to the extent that a suitable blade snow layer remains when the upper insulation sheet 46 is removed in the fall. save. The lower insulation sheet 42 can be left in place throughout the year.

In the case of land where heat is transmitted from the side of the slope or where heat is transmitted due to underground conditions, use the lower insulation sheet 4.
It has been found that it is desirable to use 2.

A convenient way to provide the insulation sheet as shown in FIG.
50 rolls 4B of insulation material having twice the length are used. During the summer, half of the insulation sheet roll 48 is unrolled to cover the exposed ground 52, as shown in FIG.

Snow that falls next winter accumulates on the insulation sheet 50 as shown in FIG. Then, once the spring is applied, the remaining half of the insulation sheet roll 48 is rolled up to cover the snow 54 as shown at 56 in FIG. Although I mentioned earlier that there are no restrictions regarding insulation sheets, I will now explain a special sheet that exhibits appropriate insulation performance to preserve the snow layer throughout the summer. The sheet is shown in FIGS. 10 and 11. The sheet comprises two aluminum foil layers 5B, 60 separated by about 0.64 crn (about 1/4 inch) with two layers of expanded polyethylene 62,64 sandwiched therebetween. The foamed polyethylene foam has a diameter of about 0.95 crn (about 1/3 inch) and is preferably arranged in a triangular shape (FIG. 11).

The foams are bonded to each other and to the insulation sheets 58 and 60 to create a strong electrical insulation with the ability to substantially limit the transmission of the sun's radiant heat and the surrounding air's heat through the insulation sheets to the snow below. constitute a material sheet. This insulation sheet can be further strengthened by coating both sides with transparent or polyethylene.

This insulating material sheet is light and very flexible, but it is durable enough to be used repeatedly for many years, so it is well worth the high price.

A further embodiment of the invention is shown in FIGS. 12 and 13. Snow 70.72 in the separated area is covered with insulation sheets 74.76. As the snow melts, the portion 78 of the slope that is not covered with the insulating material sheet becomes exposed and becomes a path for people and animals. When the time comes to remove the insulation sheet in the fall,
The preserved snow 70.72 is spread over the path.

As shown in FIG. 13, some of the lightning T0.72 is dumped with a shovel or bulldozer onto the exposed ground 78 to create a slope covered with a continuous layer of snow forming the desired root snow layer.

Yet another embodiment of the invention is shown in FIGS. 14 and 16. FIG. 14 is a plan view of an 8° slope on which a suitable blade width of snow is covered with a continuous sheet of insulation 82. For example, the width is about 12.2 m (40 ft) and the length is about 1
．． Due to the dimensions of the insulation sheet 82 being 61b (1 mile) or more, the insulation sheet is laid down;
Special equipment was developed to remove it. Rails 84,86 are laid on both sides of the slope. By conventional means (not shown) the electrically or gasoline-propelled machines 88,90 can be moved up and down steep slopes together. A common axis 92 crosses the slope
Extend between 88 and 90. The machines 88.90 rotate the shaft 92 so that the sheets of insulation are wound onto the shaft 92 as the machines descend the ramp, and the sheets of insulation are unwound from the shaft 92 as the machines ascend the ramp. (See Figure 16). Suitable features such as splines or universal joints may be provided on the shaft to compensate for uneven movement of the machine 88,90.

To wind a continuous sheet of insulation having a thickness of about 6.4 mm and a length of about 1.6 mm into a cylinder with a diameter of about 3.1 m,
It will be appreciated that the shaft 92 must be approximately 6 feet from the snow surface. The insulation sheet thus wound up is removed from the machine at the lower end of the ski slope and stored out of the way of the skis. The use of such a machine, which allows the rapid winding and rapid re-laying of insulation sheets, makes it possible to use the slope as a ski slope even in the summer. A company might invite its business partners to a ski tournament on a set date during the summer. In that case,
The machine can be used to clean up the insulation sheets on the entire slope on the morning of the ski competition.
Skiers can use the slopes all day long, and in the evening, the amount of snow lost is so small that insulation sheets can be re-laid on top of the snow, defeating the main purpose of preserving snow during the summer. Never.

The dimensions of the insulating material sheet and the dimensions of the machine described above are merely examples, and are not intended to limit their dimensions, structure, capacity, or manner of use thereof in any way. Since such a table machine can be easily designed by a mechanical engineer, a detailed explanation thereof will be omitted here.

FIG. 15 shows how the effectiveness of the insulation sheet was improved. For example, about 5.1 cm
x 7.6cm (2 inches x 3 inches) or 10.
A light foam rubber strip 94 having suitable cross-sectional dimensions of 2σ x 10.2 cIn (4 inches x 4 inches) is placed on the snow prior to placing the insulation sheet 9B on the snow 96.

The spacing between the foam rubber strips 94 is sufficiently narrow to prevent the insulation sheet from sagging and coming into contact with the snow. The air layer existing between the insulation sheet and the snow surface improves the thermal insulation effect of the insulation sheet.

FIG. 17 shows a ski slope covered with snow 104.

To aid in the explanation of the present invention, the snow-covered portion of the slope is shown as having an upper boundary, a lateral boundary, and a lower boundary designated by reference numerals 106, 108, 110° 112, respectively. .

FIG. 18 is a vertical cross-sectional view taken along line 18-18 of FIG.
14. The upper limit of snow of interest here is the part indicated by reference numeral 106, and the lower limit is the part indicated by reference numeral 10.
8. FIG. 19 is a sectional view taken along line 19-19 in FIG. 18.

Figures 17-19 include any ski slope with snow (natural snow only, natural snow and artificial snow, or artificial snow only) at the end of the ski season when the operator selects which slopes to close. It is intended that the

Snow depth and conditions at the time a slope is closed will vary widely depending on the winter's snowfall and terrain.

Remove the snow from the slope using machines if possible.
Pile up multiple piles of snow as shown in Figure 22. The arrangement of snow mountains on the slope is the shape of the slope,
Determined according to snowfall amount and operator judgment.

The snow mountain should be as high as possible, and the bottom should be as circular as possible. Once the snow mountain is made, it is covered with an insulating material sheet 118 that has the ability to preserve most of the snow during the summer and early fall. cover.

In areas with deep snow, it is possible to create snow piles of appropriate size without using all the snow available in the area. In areas with low snowfall, it may be necessary to use all the snow in the vicinity to create a pile of snow large enough to last through the summer. In all cases, the goal is to build up the snow and, by loosening it with sheets of insulation, retain enough snow to provide suitable skiing conditions when the snow is laid down in the fall. be. The area of the area where the mountain of adventure is created should be as narrow as possible than the area of the area where the snow will be collected. In other words, the percentage loss due to snow melting is inversely proportional to the height of the snow pile, so building a high snow pile over a small area is more advantageous than building a low snow pile over a large area. When using a machine, the height at the center is approximately 6.1 m (20 ft).
or more, it is easy to build a mound of snow sloping towards the bottom of the circle. The amount of melting in the summer of this type of snow pile covered with suitable insulation sheets does not exceed 20-25 qb of the total volume. Therefore, the average amount of snow on the slope when we started building the snow pile was about 61c.
In (2 feet) and if all of that snowfall was used to build the snow pile, the amount of snow remaining in the fall would be about 30 to 15 crn (1 to 0.5 crn).
ft) is sufficient to cover the area.

Figures 23, 24 and 25 are similar to Figures 20 and 2.
This figure shows the state of the slope after the snow mountain 116 shown in FIGS. 1 and 22 has been covered with snow in autumn. In FIG. 23, lines 120 and 122 indicate that the width of the slope was somewhat narrower when the snow was spread to its original depth.

In Fig. 25, lines 120 and 122 indicate the width of the slope corresponding to the boundaries 108 and 110 in Figs. 17 and 18 when the amount of snowfall is made shallower in accordance with the amount of melting in the summer. be.

In some cases, as shown in FIG. 27, to increase the amount of snow in the preserved snow pile, the insulation sheet 118 is removed and artificial snow is added to restore the snow pile to its original height. It has been found that it is desirable and practical to do so. This is due to the layer of snow left over from spring.
It is used when the snow is large enough to get the desired depth at the beginning of autumn. Artificial snow can always be added when temperatures drop below freezing. Temperatures dropping below freezing occur in early autumn. By repeatedly adding artificial snow, a pile of snow sufficient to make the selected area skiable when packed with snow is obtained. Second
FIG. 7 shows the situation after adding artificial snow 124 to the initial snow pile 116 and covering it again with the insulation sheet 118.

Since the movement of snow is aided by gravity, the work of piling up remaining snow into a snow mountain shape in the spring and spreading it on the ground in the fall should proceed from the top of the slope to the bottom as much as possible, but the machine operator The work may be changed depending on the judgment of the person.

It will be appreciated that for illustrative purposes, the thickness of the insulation sheet relative to the size of the snow pile is exaggerated in the figure.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-section of a sloped terrain covered by snow covered with an insulation sheet; Figure 2 is a vertical cross-section of an example of an insulation sheet; Figure 3 is a vertical cross-section of an example of an insulation sheet; a top view of one type of insulation sheet installed in the device;
Figure 4 is a side view of Figure 3 when the insulation sheet is removed from the slope by the winding device, Figure 5 is a plan view of Figure 4, and Figure 6 is between the ground and the snow and above the snow. FIGS. 7 and 8 are vertical cross-sectional views of another embodiment of the invention using two sheets of insulating material; FIGS. 9 is a sectional view taken along line 9-9 in FIG. 6, FIG. 10 is an enlarged cross-sectional view of a part of a particular type of insulation sheet, FIG. 11 is a plan view of FIG. 10, and FIG. 12 Figure 13 is a vertical section similar to Figure 1 with the difference that the passage is provided; Figure 13 is a snow-covered passage from an adjacent area covered with snow after removal of the insulation sheet; A vertical cross-sectional view similar to FIG. 12 showing the area, FIG. 14 is a vertical cross-sectional view similar to FIG. A plane showing a machine provided on both sides of the ramp to support said rotating shaft together, employed for winding the insulation sheet onto a rotating shaft for unwinding and removing the insulation sheet from the ramp. Figure 15 is a vertical cross-sectional view showing a hypothetical sweeper that holds the insulation sheet at a short distance from the snow m1, and Figure 16 is an enlarged view of the winding mechanism along line 16-16 in Figure 14. 17 is a plan view of a snow-covered slope illustrating another embodiment of the present invention; FIG. 18 is a vertical cross-sectional view taken along line 18-18 of FIG. 17; FIG. Figure 19-19+
16! 20 is a plan view of the ski slope in FIG. 17 with snow piled up in a snow mountain shape, FIG. 21 is a vertical sectional view along line 21-21 in FIG. 20, and FIG. 21 is a vertical sectional view taken along the line 22-22, and FIG. 23 is a vertical cross-sectional view taken along the line 22-22 of FIG. 21, and FIGS.
24 is a vertical sectional view taken along line 24-24 in FIG. 23, FIG. 25 is a vertical sectional view taken along line 25-25 in FIG. 24, and FIG. 26 covers a larger area. Figure 27 is an enlarged view showing a pile of snow to which artificial snow has been added. 10.42,46,74,76.118 ・ ・ ・
・Insulating material sheet, 14...-Insulating material, 84.86...
...Rail. Patent applicant Adrian Proche Andre Proche

Claims (22)

[Claims] (1) The process of closing ski resorts on ski slopes while a significant layer of snow still remains on said slope, combined with the underlying snow, throughout the spring, summer and fall when temperatures are above freezing. Conditions for skiing if, by the time of the fall snowfall, there is adequate ground snow to receive the first snow and retain that first snow to create suitable skiing conditions, and such ground snow does not exist. covering at least a portion of the slope with a layer of an insulating material having properties that limit the degree of melting of the remaining snow so as to provide skiable conditions on an earlier day than the day when the slope is suitable; removing the insulation sheet from the snow-covered portion of the slope soil after the temperature has decreased to a temperature at which the snow continues to be preserved as a suitable root snow without the aid of How to bring forward the day when ski slopes become skiable in the fall. (2) The method according to claim 1, wherein the insulating material is temporarily removed from the snow when the temperature is above the freezing point in order to make the slope temporarily usable. and the period of its removal is limited so as not to defeat the purpose of preserving said snow until autumn. (3) The method of claim 1, further comprising the step of placing a layer of insulation over the slope when the ground is exposed prior to closing the slope, so that the slope is closed and the snow on the slope is at least partially covered by said layer of insulation, characterized in that the snow to be stored during the coming summer is contained between the upper and lower layers of insulation. How to do it. (4) A method according to claim 1, comprising the steps of covering separated areas of the slope to provide intermediate uncovered portions for use as passageways during the summer; providing a continuous snow-covered ski slope by moving said snow sections from separated, covered areas to intermediate uncovered areas when said insulation layer is removed; A method characterized by comprising: (5) The method of claim 1, wherein said step of covering the snow covers a longitudinal distance extended in successive layers of said insulation material of a type that can be wound into successive rolls. A method characterized in that it comprises the step of traversing the snow so that the winding mechanism can remove and re-cover the insulation layer. (6) The method of claim 1, further comprising the step of distributing fall available snow to create a more desirable surface for skiing after removing the insulation. How to characterize it. 7. A method according to claim 6, characterized in that the distribution step includes the step of utilizing available snow in an area of the slope adjacent to the covered area. (8) the process of collecting snow present on a ski slope when the ski slope is closed in the spring to create one or more snow piles and covering those snow piles with sheets of insulating material; , the process of preserving a large portion of the covered snow over the summer and early fall periods and preventing excessive melting of the stored snow after the insulation sheet cover is removed. the process of removing the covering of said insulation sheet of said snow pile in autumn when the temperature has fallen to a sufficiently low temperature and then from the uncovered snow pile to a depth satisfactory for skiing on the slope; . Spreading snow on selected areas of the slope. (9) The method according to claim 8, wherein while the snow mountain is covered, the peripheral edge of the insulating material sheet is
A method comprising the step of securing the snow mound to surrounding soil in such a way as to prevent ambient air from entering the underside of the insulation sheet. (10) The method according to claim 8, wherein before distributing the snow on the snow pile in autumn, the insulating material sheet is removed from the snow pile when the temperature falls below the freezing point, A method characterized by adding an amount of artificial snow to the snow pile to cover it again. (11) Sufficient snow on the ski slope during the period between the last snowfall in the spring and the first snow in the fall to provide an adequate base snow layer to receive natural snow in the fall or to receive artificial snow in the fall. A device for retaining snow that includes a normal ski slope, a layer of residual winter snow that almost covers a part of the ski slope, and an insulating sheet that covers the snow to be retained, and the insulating sheet is removed in the fall. natural snow or snow so that skiing can begin on the covered portion of the slope before the slope would normally be available for skiing if the remaining snow had not been retained by the device. to the extent that there remains adequate ground snow to receive artificial snow, said insulating sheet acting in combination with the remaining snow has an insulating property that minimizes the melting of said remaining snow; A snow retention device that retains sufficient snow on a ski slope during the period between the last snowfall in the spring and the first snowfall in the fall to receive snow or provide an adequate basis for receiving artificial snow in the fall. . (12) The device according to claim 11,
An apparatus characterized in that a mechanical means for removing the insulating sheet is provided on the side of the slope. (13) The device according to claim 12,
The sheet of insulation extends longitudinally along the slope, and the mechanical means is movable up to remove the sheet of insulation from snow on the slope or over the snow on the slope. A device characterized in that it comprises sheet winding means that can be moved down for laying. (14) The device according to claim 13,
The mechanical means comprises toothed tracks on the sides of the slope, a first machine capable of moving up and down the slope on at least one of the tracks, and synchronously with this first machine. a second machine on another track capable of moving up and down, an axle carried by those machines and extending across said slope, and means for rotating said axle to form said sheet winding means; A device characterized by comprising: (15) The device according to claim 11,
The insulation sheet is placed on the snow before being laid on the snow, so that when the insulation sheet is laid on the snow, the insulation sheet is separated from the snow to provide an air space. spacer means. (16) The device according to claim 15,
Apparatus characterized in that said spacer means is a lightweight foam rubber strip. (17) The device according to claim 12,
Apparatus characterized in that the sheet of insulation is relatively longer than its width and is positioned across the slope. (18) The device according to claim 17,
The mechanical means is arranged in such a way that the mechanical means can be positioned adjacent an edge of the insulation sheet across which the sheet of insulation is disposed, allowing the sheet of insulation to be removed at any time. A device characterized in that it can move along a slope. (19) The device according to claim 12,
Apparatus characterized in that said sheet of insulation is made of a flexible material that can be wound onto said mechanical means. (20) The device according to claim 11,
Each of said sheets of insulation comprises an upper layer of aluminum foil, a lower layer of aluminum foil, and means interposed between said layers to minimize conduction of heat from said upper layer to said lower layer. A device characterized by comprising: (21) The device according to claim 20,
A device characterized in that said means between said layers comprises means for forming a plurality of confined air spaces, said means being fixed on opposite sides of said layers. (22) The device according to claim 11,
The snow on the ski slope used for skiing in early autumn is covered in separated areas by insulation sheets, the uncovered part of the slope forming a passage area and being preserved by the insulation sheets. The amount of snow is partially spread over the uncovered area after the insulation sheet is removed in the fall, and the area covered by the insulation sheet of the slope and the area covered A device characterized in that it is of a suitable amount to provide conditions for skiing over the length of said path area.