Patent Description:
It is becoming more and more common to store snow made for ski slopes or cross-country trails at different kinds of ski and winter sport resorts, as well as for first-snow skiing tracks made by cities, for example, in heat-insulated snow storages over the summer. To preserve the snow over the summer, the snow must be covered with a sufficient amount of appropriate heat-insulating materials since even The Nordic countries may experience outdoor temperatures up to +<NUM> during the summer months. Besides, the walls and roof of the snow storage are exposed to a lot of direct sunshine in the summer, and, in rainy weather, the snow storage is wet by rainwater.

The heat-insulation of the snow storage consists of heat-insulators added on top of a snow mass piled up at a desired snow storage site. Of these materials, the following continue to be the most common ones: sawdust, different kinds of clothes, as well as polystyrene and/or polyurethane insulation boards. The applied methods work well in other aspects but, in the step of insulating and dismantling the snow storage, they require a lot of manual labor as well as transporting a variety of heat-insulating materials from their storage site to the snow storage and back, causing high labor and transportation expenses.

Document <CIT> discloses a snow storage for storing snow and ice till summer for utilizing them as a cooling-heat energy source. According to the document a heat insulation covering comprising heat-insulating materials and rigid framework is assembled above a pile of snow to be stored to form the snow storage.

Document <CIT> discloses equipment for preserving snow. The equipment comprises several flat covering elements made of foamed polyethylene and connected to each other.

Document <CIT> discloses a hail-resistant vehicle cover. The vehicle cover comprises a plurality of cover panels pivotably attached to each other to form a foldable cover.

The invention aims at providing a novel method of heat-insulating a snow storage, making it faster and easier to install and uninstall the heat-insulation of the snow storage and, thus, resulting in lower labor and insulation material handling expenses related to the storage of the snow over the summer. In particular, the invention aims at providing a method of simplifying the operations of installing and uninstalling the heat insulation of the snow storage and, thus, resulting in a significant decrease of the high amount of work and expenses currently involved therein. Moreover, the invention aims at providing equipment for carrying out the method according to the invention.

The method according to the invention achieves the object of the invention in that at least some of the heat-insulators used for covering the snow pile requiring heat-insulation consist of insulation board mats which are made out of insulating boards joined together in an accordion-like fashion, and, which, as the snow storage is insulated, are pulled to lie side by side and/or one after another on the top/sides of the snow storage, and which, once the snow stored in the snow storage is taken out, are pulled back to lie next to the snow pile, in an accordion-like configuration, where they are stored while the snow stored in the snow storage is being used (i.e. during the skiing season) and from where they are taken back into use when a snow pile intended for the next season's snow supply is stored at the same site. To put it more precisely, the method and equipment according to the invention are characterized in what is set forth in the independent claim <NUM> and in the independent claim <NUM>, respectively. The dependent claims <NUM> to <NUM> and the dependent claims <NUM> to <NUM> disclose preferred embodiments of the method according to the invention and preferred embodiments of the equipment according to the invention, respectively.

An advantage of the method and equipment according to the invention is that, as the heat-insulated snow storage is created, they eliminate a slow and laborious step of installing individual insulation boards on the top and sides of the snow pile, and that, as the snow storage is taken into use, they do not have to be individually collected off the snow pile. In addition, as a result of how the heat-insulating materials are stored in the method according to the invention, the heat-insulating materials do not have to be transported over long distances to a storage and, then, from the storage back to the proximity of the snow pile to be re-installed on a new snow pile stored over the summer and intended for the needs of the next winter. All these measures facilitate the set-up and use of snow storages by reducing and simplifying the work steps involved in creating the snow storages and in taking them into use, the expenses of the use of the snow stored over the summer thus becoming significantly lower than in the previously known methods.

In the following, the invention will be explained in more detail with reference to the accompanying Figures wherein.

In the snow storage <NUM> shown in <FIG> and heat-insulated by the method according to the invention, the heat-insulation of the roof <NUM>, end walls <NUM> and <NUM> as well as the lateral walls <NUM> and <NUM> parallel to the longer sides is provided by insulation board mats <NUM> consisting of insulation boards <NUM> joined together in an accordion-like fashion. Typically, the insulation boards <NUM> of the insulation board mats <NUM> are polyurethane, polystyrene or similar insulation boards, for example. Alternatively, the insulation boards <NUM>, or some of them, can be other insulation boards, such as foam rubber or cellular plastic boards. It is possible to select the outer dimensions of the insulation boards <NUM> of the insulation board mats <NUM> case by case or to use standard-size insulation boards. The insulation boards <NUM> must be thick enough to sufficiently acknowledge the climatic conditions prevailing in the location of the snow storage <NUM>.

The corners <NUM> between the end walls <NUM> and <NUM> as well as the lateral walls <NUM> and <NUM> of the snow storage <NUM> shown in <FIG> are insulated by triangular corner inserts <NUM> fitted therein. Herein, the corner inserts <NUM> are made of an integral piece of an elastic and bendable heat-insulating material, such as a foam rubber or cellular plastic board. The outer dimensions and thickness of the corner inserts <NUM> may also vary according to the size and heat-insulation requirements of the snow storage. In an embodiment of the method and equipment according to the invention, the corners <NUM>, and therefore, the end walls <NUM> and <NUM> of the snow storage as well, can also be insulated by means of inner walls made out of snow and/or ice, for example, as well as by means of a heat-insulating layer provided on the inner walls by using sawdust and/or pykrete, i.e. frozen sawdust, accumulated thereon.

The insulation materials of the roof <NUM>, end walls <NUM> and <NUM> as well as the lateral walls <NUM> and <NUM> comprise insulation board mats <NUM> consisting of individual insulation boards <NUM>, or, of groups of insulation boards put together out of several joined insulation boards <NUM>. The individual insulation boards <NUM> or the insulation board groups are pivotably joined together, alternately at the upper corners and the lower corners of the transversal end edges <NUM> thereof. The continuous insulation board mat <NUM> formed thereby and comprising several insulation boards is foldable into an accordion-like insulation board bundle <NUM>' and re-openable into a continuous insulation board mat <NUM> (as is shown in <FIG>). When the pivotably joined sections are not individual insulation boards <NUM> but insulation board groups consisting of multiple insulation boards <NUM>, the insulation boards joined together in the insulation group are preferably fixed together, or inserted into a single bag or sleeve made from a suitable fabric, to hold them against each other, as a single continuous piece of board.

In the snow storage of <FIG>, the successive insulation boards <NUM> are pivotably connected together by a waterproof cloth <NUM> (such as a PVC cloth), to form an accordion-like structure, as shown in <FIG>. In this case, the pivotable connection is achieved by inserting the successive insulation boards into bags made of a fabric-like material, or, into sleeves 19a open at two opposite ends, wherein there are several bags or sleeves one after another, joined, at an edge thereof, to each other by a suitable joint 19b. Thus, the insulation boards <NUM> inserted into the bags or sleeves 19a are pivotably joined together at their opposite edges, by the joints between the bags or sleeves 19a. In a similar embodiment of the snow storage <NUM>, two or more insulation boards can be inserted into a single bag or sleeve 19a, one after another and/or side by side, the bags or sleeves 19a thereby pivotably connecting groups of insulation boards to each other, in the way described above.

As appears from <FIG>, the ends and the middle portions of the heat-insulated snow pile <NUM> are covered with several adjacent insulation board mats <NUM>. As for the snow storage of <FIG>, three successive insulation board mats <NUM> are pulled over the snow pile <NUM>. Two of them lie on the sides (principally at the lateral walls <NUM> and <NUM>) while one of them lies on the roof <NUM> of the snow storage <NUM>, on top of the snow pile <NUM>. In another similar embodiment, there can also be one, two or more than three successive insulation board mats <NUM>. In this case, the position of the insulation board mats <NUM> is generally selected case by case to restrict the entrance of rainwater into the snow pile as far as possible. In the snow storage of <FIG>, the entrance of rainwater is also restricted by a joint shield <NUM> provided on top of the snow pile. Here, it covers the midmost insulation board mats <NUM> as well as the joint areas between them and the first and the last insulation board mats <NUM>. Thus, rainwater cannot enter the snow pile <NUM>, at least not very easily, through the joints between the successive insulation board mats <NUM>.

<FIG> is a view of the snow storage <NUM> of <FIG>, with the insulation board mats <NUM> and the corner inserts <NUM>, provided in the front end <NUM>, as seen from the direction of the Figure, and in the corners <NUM>, respectively, removed, and with the first central insulation board mat <NUM> of this end face pulled off the snow pile, as the snow storage <NUM> is taken into use. In <FIG>, the joint shield <NUM> provided on the roof of the snow storage and the joint shields <NUM> between the insulation board mats <NUM> are removed as well.

The equipment for insulating a snow pile according to the invention may comprise, in addition to the variety of heat-insulating materials, a pulling device for opening up a bundle of insulation boards <NUM>' into an insulation board mat <NUM> and for pulling it onto the snow pile <NUM>. The pulling device can be an electrically or combustion engine driven winch or the like, for example, allowing each insulation board bundle <NUM>' to be opened up and pulled onto the snow pile <NUM>. Alternatively (especially for smaller snow storages), some or all of the insulation board bundles <NUM>' can be opened up by manual pulling. A suitable pulling member, such a pulling rope, wire rope, strap or the like, is attached to an end of the insulation board bundle <NUM>' and taken over the snow pile to allow the insulation board bundle <NUM>' to be opened up and pulled onto the snow pile <NUM> by manually pulling at the pulling member.

When insulating a snow pile <NUM> made at a storage site by the method according to the invention, the heat-insulation is done by using the insulation board mats <NUM> and the corner inserts <NUM> as described above as well as different kinds of other heat-insulating materials provided in the intermediate areas between the insulation board mats <NUM>. After piling up snow, the accordion-like insulation board bundles <NUM>' provided or brought next to the snow pile <NUM> are opened up into insulation board mats <NUM> and pulled onto the snow pile <NUM>. As for the snow storage <NUM> of <FIG>, the accordion-like insulation board bundles <NUM>' are provided on all sides of the snow pile <NUM>, the insulation board bundles <NUM>' intended for each side are situated next to this side. The location of the insulation board bundles <NUM>' intended for the roof <NUM> of the snow storage <NUM> is selected case by case by to allow them to be pulled onto the snow pile <NUM> as effortlessly as possible. Before starting the pulling operation, the insulation board bundles <NUM>' provided next to the snow pile <NUM> can be tilted towards the snow pile <NUM> to make it easier to open up them by pulling them at the topmost insulation board towards the snow pile <NUM>. The most common way of opening up the insulation board bundles <NUM>' of pulling them to lie on the top and the sides of the snow pile <NUM> is to use an electrical pulling device, such as an electrical pulling winch. The pulling winch can be a pulling winch provided on a terrain vehicle, for example, the vehicle being drivable to a suitable position with respect to the pulling direction. The insulation board bundles <NUM>' can also be opened up manually and pulled onto the snow pile <NUM> by means of suitable hand-operated pulling means (such as ropes or straps) extended over the snow pile to the other side of thereof. This allows the insulation board bundles <NUM>' intended to be installed in different locations on the top and the sides of the snow pile <NUM> to be conveniently moved to these desired locations by pulling at the pulling means. Often, it is also possible to use a driven pulling device for opening up and pulling the larger and heavier ones of the insulation board bundles <NUM>' onto the snow pile <NUM> and to only use manual force on the smallest ones of them.

Before pulling the insulation board bundles <NUM>'onto the snow pile <NUM> and after removing them from the snow pile <NUM>, they are stored next to the snow pile <NUM> and laterally moved off the snow pile <NUM>, over a required distance (aside from a trail of a ski slope, for instance). To prevent the insulation board bundles <NUM>' from getting wet and from freezing, they are covered with a suitable, preferably waterproof sheet (such as a plastic or PVC cloth) for the duration of use of the snow of the snow storage (i.e. mostly for the entire ski season).

As for the snow storage <NUM> of <FIG>, all of the insulation board bundles <NUM>' are situated, at the beginning of the insulation step, on the side of the snow pile <NUM> encompassing their intended location on top of the snow pile, prior to pulling them onto the snow pile, and, after pulling them off the snow pile <NUM> and re-folding them into insulation board bundles <NUM>'. In some embodiments, it is also possible to store some of the insulation board bundles <NUM>' on the side opposite to the side of the snow pile <NUM> where the rest of the insulation board bundles <NUM>' are situated. To do this, these insulation board bundles <NUM>' are pulled in a counter-direction with respect to the insulation board bundles <NUM>' stored on the opposite side of said snow pile <NUM> as they are pulled onto the snow pile <NUM> or off the snow pile <NUM>.

The insulation board mats are pulled to lie side by side on top of the snow pile <NUM> so that there are several insulation board mats <NUM> on top of the snow pile, with their lateral edges <NUM> against each other. In general, it is not necessary to attach the (longitudinal) lateral edges <NUM> of the adjacent insulation board mats to each other but, usually, they are just positioned (by suitably pulling by means of a winch or a hand-operated pulling device) near each other, without leaving an excessively long distance (usually under <NUM>) between the opposite lateral edges <NUM>. The spaces between the adjacent insulation board mats <NUM> are filled with an appropriate heat-insulating structure <NUM> consisting of heat-insulating materials <NUM>, <NUM> and <NUM>. As for the snow storage of <FIG>, the filling is carried out, as is shown in Figure <NUM>, prior to pulling the insulation board mats <NUM> onto the snow pile <NUM>, by providing the areas between their lateral edges with a sealing cloth <NUM>. The sealing cloth <NUM> can be a single elongated piece of a waterproof fabric or plastic (a piece of PVC fabric having a thickness of approximately <NUM> to <NUM>, for example) extending over the entire snow pile. It is also possible to press (by means of a suitable tool) a groove in this point of the surface of snow pile <NUM>, the sealing cloth <NUM> thus forming a chute in the areas between the lateral edges <NUM> of the insulation board mats <NUM> to drain off any rainwater that has entered between the insulation board mats <NUM> from the snow pile <NUM>. Thereafter, the insulation board mats <NUM> are pulled into place and then onto the joint area, and, if necessary, an intermediate insulation <NUM> (such as a foam rubber or cellular plastic insulation), with an overlying joint shield <NUM>, such a geotextile, is provided between the lateral edges <NUM> of the insulation board mats <NUM>. As an example, the joint shield <NUM> can be fixed on the insulation board mats by means of binding members <NUM> installed at the lateral regions of the insulation board mats, such as by means of tie-down straps tightened against the insulation board mats <NUM> (as shown in Figure <NUM>). This filling between the lateral edges <NUM> of the adjacent insulation board mats <NUM> provides heat-insulation and restricts the entrance of rainwater into the snow pile <NUM>, through the spaces between the adjacent insulation board mats <NUM>. However, in some cases, if it is desirable to attach the insulation board mats <NUM> to each other, it can be done with an adhesive member removably attaching to the insulation board mats, such as with adhesive tape or Velcro ® fastener tapes/strips.

When several successive insulation board mats <NUM> are pulled onto the snow pile <NUM>, two or more of the insulation board mats <NUM> pulled onto the snow pile are positioned one after another, with a first end of a first insulation board mat <NUM> abutting a second end of a second insulation board mat <NUM> and with a rear end of a third insulation board mat <NUM> abutting a first end of the second insulation board mat <NUM>. If it desirable to attach the insulation board mats <NUM> one after another, it can be done in a way similar to the way they are attached, side by side, at their lateral edges <NUM>, i.e. with a suitable fastener removably provided between the end edges <NUM> of the insulation board mats <NUM>. It is common to use two or more successive insulation board mats <NUM> because the snow storage <NUM> is usually very large and because the use of a single insulation board mat <NUM> for covering the entire distance from one side of the snow pile <NUM> to the other side requires an insulation board mat <NUM> consisting of several dozens of insulation boards <NUM>. This increases the size of the insulation board bundles <NUM>' to an extent that their weight and dimensions can make it hard to pull them onto the snow pile <NUM> and off the snow pile and to carry out any other operations needed.

A finished heat-insulation of the snow storage <NUM> created by the method according to the invention does not usually require other heat-insulating materials to be provided the insulation board layer of the insulation board mats <NUM>. However, if it is desirable to do so, it is possible to lay an insulating cloth, such a geotextile and/or moisture shield, such as a plastic or waterproof cloth (such as a PVC cloth) over the insulation board mats. This eliminates the need of the sealing cloth <NUM> at the joints between the lateral edges <NUM> of the insulation board mats <NUM>.

<FIG> is a longitudinal cross-sectional view of an insulation board mat, presenting an insulation board mat <NUM> having individual insulation board bundles <NUM>' inserted into bags or sleeves 19a (i.e. laterally open fabric sleeves) made of waterproof fabric <NUM>, as a structural option. Here, the waterproof cloth <NUM> enclosing the insulation boards <NUM> has joints 19b parallel to the transversal edges of the insulation boards and joining the overlying waterproof fabric <NUM> and the underlying waterproof fabric <NUM> of the insulation boards <NUM> together, welded, glued or sewed between the transversal edges of successive insulation boards <NUM> (i.e. edges perpendicular to the longitudinal direction of the insulation board mats <NUM>). The joints 19b are positioned between the fabric layers by alternating the successive joints 19b at the level of the lower surface and the upper surface of the insulation boards <NUM>. Thus, articulations transversal to the insulation boards <NUM> are provided therebetween, allowing the insulation board mat to be folded into an accordion-like insulation board bundle <NUM>', as shown in <FIG>.

Claim 1:
A method of providing a snow storage (<NUM>) with heat insulation, the method comprising covering a snow pile (<NUM>) made at a snow storage site with heat-insulating materials (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) of which at least some are insulation boards (<NUM>), characterized in that
- the insulation of the snow pile (<NUM>) is carried out by using insulation board mats (<NUM>) which include several insulation boards (<NUM>), or insulation board groups consisting of several insulation boards attached against each other, side by side and/or one after another, and which are pivotably joined together, alternately at the upper corners and the lower corners of their opposite transversal end edges (<NUM>), the resulting continuous insulation board mat (<NUM>) composed of several insulation boards one after another being foldable into an accordion-like insulation board bundle (<NUM>') and re-openable into a continuous insulation board mat (<NUM>),
- as the snow pile (<NUM>) is heat-insulated, the accordion-like insulation board bundles (<NUM>') are opened up and pulled to lie side by side and/or one after another on the top/sides of the snow pile (<NUM>), the insulation board mats (<NUM>) which have been opened up and pulled onto the snow pile (<NUM>) thus covering at least a portion of the snow pile,
- as the insulation board mats (<NUM>) are removed from the snow storage (<NUM>), the insulation board mats (<NUM>) are pulled off the snow pile (<NUM>) and folded back into insulation board bundles (<NUM>') with an accordion-like configuration.