Apparatus for creating and maintaining an ice slab

Abstract

Apparatus for creating and maintaining an ice slab for skating purposes, or an ice chute for a toboggan slide, or for maintaining a layer of snow for skiing. The apparatus includes pluralities of small diameter flexible plastic tubes arranged in grids in portable mats with the tubes placed close to one another and arranged with each input or supply tube portion closely adjacent to an outlet or return tube portion providing an advantageous uniform temperature effect at a small distance above the tubes. A low temperature anti-freeze liquid is pumped through the tubes to provide the desired uniform cooling effect, and the portable mats each include a pair of sub-headers which can conveniently be coupled together with main headers to form a large grid the size of an ice skating rink, or a ski slope. For a rink these small flexible tubes may thereafter be covered with a thin layer of sand, or other protective material, and water is then introduced into the rink and is frozen by the low temperature refrigerant passing through the various tubes. By virtue of the small diameter of the tubes, ethylene glycol or other similar low temperature anti-freeze liquid (which would be very expensive with conventional systems) can economically be used to practice the invention disclosed herein. In the case of a ski slope, the small flexible tubes are covered with a thin layer of sand or dirt, and the circulation of the low temperature refrigerant serves to maintain, i.e. to "hold," a skiable layer of snow (either natural or manmade snow or a mixture of them) on the ski slope during thawing periods when the snow normally would melt away.

We claim: 
     
       1. A flexible portable plastic tubing mat adapted to be laid side-by-side with other similar mats for creating and maintaining an ice slab for skating and for preventing snow from melting on a ski slope and adapted to be laid end-to-end with other similar mats for creating an ice chute or trough for a toboggan slide or similar sliding purposes, a. said portable mat having a length many times greater than its width with a plurality of small diameter flexible plastic tubing members extending lengthwise of said mat adapted to have cooled anti-freeze liquid pumped therethrough,   b. said flexible plastic tubing members having an inside diameter in the range from one-eighth to three-eighths of an inch,   c. securing means connected to said tubing members for securing them in a grid pattern in said mat,   d. said mat including supply and return sub-headers extending across one end of said mat with the ends of a plurality of said tubing members being connected respectively to said supply and return sub-headers with the direction of flow of the anti-freeze liquid being opposite in neighboring tubing members in the mat,   e. said flexible portable mat being rollable into a roll for ease of transportation, and   f. said sub-headers being adapted to be connected to main headers in an installation for interconnecting the plurality of said tubing members through the sub-headers to the main headers.   
     
     
       2. A flexible portable plastic tubing mat as claimed in claim 1 in which said small diameter plastic tubing members are co-extruded in pairs of such members and the ends of the tubing members are connected to said supply and return sub-headers to produce an opposite direction of the anti-freeze flow in the respective tubing members of each pair. 
     
     
       3. A flexible portable plastic tubing mat as claimed in claim 1 in which the mat is about 4 feet wide and at least 85 feet long. 
     
     
       4. A flexible portable plastic tubing mat as claimed in claim 1 in which supply and return sub-headers extend across both ends of said mat with the ends of a plurality of the tubing members connected respectively to supply and return sub-headers at opposite ends of the mat. 
     
     
       5. A flexible portable plastic tubing mat as claimed in claim 1 in which said small diameter plastic tubes are composed of ethylene vinyl acetate. 
     
     
       6. A flexible portable plastic tubing mat as claimed in claim 5 in which said securing means include tapes extending transversely along the mat at spaced positions along the length of said mat. .Iadd. 7. A flexible portable plastic tubing mat adapted to be laid side-by-side or end-to-end with other similar mats for creating and maintaining a frozen area, a. said portable mat having a length many times greater than its width with a plurality of small diameter flexible plastic tubing members extending lengthwise of said mat adapted to have cooled anti-freeze liquid pumped therethrough,   b. said flexible plastic tubing members having an inside diameter in the range from one-eighth to three-eighth of an inch,   c. securing means connected to said tubing members for securing them in a grid pattern in said mat,   d. said mat including supply and return sub-headers extending across one end of said mat with the ends of a plurality of said tubing members being connected respectively to said supply and return sub-headers with the direction of flow of the anti-freeze liquid being opposite in neighboring tubing members in the mat,   e. said flexible portable mat being rollable into a roll for ease of transportation, and   f. said sub-headers being adapted to be connected to main headers in an installation for interconnecting the plurality of said tubing members through the sub-headers to the main headers. .Iaddend.