US 3721418 A
Description (OCR text may contain errors)
United States Patent Vincent 1March 20, 1973 54] NATURAL ICE RINK MOULD 3,426,109 2/1969 Pempster ..249/65 x  Inventor: Eric F. Vincent, 641 Geneva Park Drive Burlmgton, Omar"), Canada 2,211,958 8/1940 Mahaffey ..137/587 x 22] Filed: Feb. 25, 1970 Appl. No.: 14,061
Foreign Application Priority Data March 25, 1969 Canada ..46,709
U.S. CI. ..249/1, 62/235, 249/112 Int. Cl. ..B28b 7/34 Field of Search ..62/71, 530, 235; 249/1, 65, 249/112, 10; 137/587; 46/87, 90; 18/DIG.
 References Cited UNITED STATES PATENTS 962,954 6/1910 Green ..62/235 2,616,096 11/1952 Hasselquist 2,996,896 8/1961 Johnson ..62/235 X FOREIGN PATENTS OR APPLICATIONS Canada ..249/10 Germany ..249/10 Primary Examiner-.1. Spencer Overholser Assistant Examiner-B. D. Tobor AttorneyAlfred W. Breiner  ABSTRACT A one-shot mould for forming natural ice rinks is provided. It includes a pair of sheets of synthetic thermoplastic material, e.g. polyethylene, whose peripheral edges are sealed together. The bottom of the two sheets is water-tight and can conform to the shape of an irregular surface. The top has a water inlet aperture, and preferably also more holes to permit the escape of entrapped air as water fills the enclosure.
8 Claims, 7 Drawing Figures PATENTEDMARZOISYS SHEET 2 OF 2 FIG] NATURAL ICE RINK MOULD BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a portable mould for use in the formation of natural ice rinks. More particularly, it is directed to such moulds which are especially adapted for use in the formation of natural ice rinks, for example, on private lawns or the like. The invention is also directed to a novel method for the formation of natural ice rinks.
2. Description of the Prior Art Outdoor ice sports have previously been generally confined to frozen ponds, streams or other naturally occurring bodies of water since most homeowners are unwilling to destroy lawn areas for the formation of rinks for ice sports, such as skating or the like and do not wish to incur the expense and labor involved in even shallow excavation.
At the present time, such outdoor ice rinks may be made by flooding an area, either open or enclosed along the sides and ends, until a suitable ice surface has formed. This method is time-consuming and impractical, since water is wasted and the rink boards are expensive and require storage. When the area is flooded without rink boards, the water runs to the lowest points which may be off the property. The area is left only partially frozen and porous. Subsequent to further flooding, the area must be further packed and sealed and the porous areas frozen with water until the entire area is water-tight. The ice has generally followed the contour of the base which is usually uneven or sloped.
When the area is enclosed by rink boards, the water leaks under the boards unless they are entrenched in place and backfilled before the ground has frozen. When the boards are erected after the ground has frozen, water leaks under the boards through the space between the bottom straight edge of the boards and the contour of the ground. These spaces must be packed with snow and frozen with water until perfectly sealed. When the boards are erected on top of snow-covered ground, the spaces are blocked with snow; however, they must be packed and frozen with water until sealed water-tight, otherwise, water will leak through the snow base and under the boards. Water also leaks through the joints where the lengths of boards are joined end to end, unless they are sealed with packed snow and frozen water, or sealed with another piece of wood overlapping the seam.
A further problem must be avoided where narrow boards are used for the enclosure and where the area slopes to the extent that the vertical distance between the upper and lower limits of the slope is greater than the width of the boards. When this occurs, a total flat ice surface is impossible to obtain since after the level of water reaches the top edge of the boards at the lowest end of the slope, it overflows and is no longer contained in the area. This problem is difficult to anticipate with the naked eye. If the boards are set with a carpenters level, wide spaces are left to be filled, otherwise, wider boards are required.
It has been proposed to provide a mould for formation of a natural ice skating rink in a form by which it becomes a portable ice skating rink which may be set up during the winter season, being placed upon a reasonably level surface such as a lawn, paved area, or
the like. following the skating season it may be readily dismantled and stored. Such portable ice skating rink included members providing a frame and sheeting (which was thin, highly flexible to conform closely to an irregular surface, e.g. a tough, water impervious polyethylene plastic having a thickness of the order of 0.003 to 0.005 inch), the sheeting being arranged to extend through the area defined by the frame' with its major portion arranged to rest on a supporting surface and with its edge portions upturned and secured to the frame for the ice-containing enclosure. It was alleged that such a skating rink had the particular advantage in that it may be used without damage to a lawn. Furthermore, it was alleged to be highly durable and required for the formation of the ice surface only a small quantity of water ranging, for example, from a depth of about one inch to a maximum ofa few inches. I
While such a portable skating rink does have some advantages, its disadvantages outweigh them. Thus, since the portable skating rink is open-topped, it is subject to the vagaries of inclement winter weather. Since it takes several days for water to freeze to a suitable skating surface, any snowstorm would ruin the skating surface.
In addition, for a skating rink of any reasonable dimensions, e.g. of 8 feet by 16 feet, the weight of the framework and the length of the boards would make it exceedingly difficult to maneuver into position in assembled condition. The rink would therefore have to be assembled on site, which may be awkward.
Furthermore, the surface upon which the rink is to be placed must be approximately level or at least no more slope than 1 in 30. For sloping surfaces, it would be almost impossible to provide a level skating surface.
SUMMARY OF THE INVENTION Aims of the Invention Objects of this invention include the provision of a truly portable natural ice rink mould, and one which is completely enclosed so as to protect the surface of the ice which is being formed.
Broad Statements of the Invention By one broad aspect of this invention, an expendible mould is provided for forming an ice surface, the mould comprising a pair of sheets of substantially similar shape, the peripheral edges thereof being either integral or sealed to one another to form a water-tight enclosure, the sheets being formed of a synthetic thermoplastic material, one of the sheets being water-tight and adapted to be the bottom, and being thin and highly flexible to conform closely to the shape of an irregular surface, the other of the sheets being adapted to be the top and being provided with a water inlet aperture.
By another aspect of this invention, there is provided, in combination, an enclosure including a pair of sheets of substantially similar shape, the peripheral edges thereof being either integral or sealed to one another to form a water-tight enclosure, the sheets being formed of a synthetic thermoplastic material one of the sheets being water-tight and adapted to be the bottom, and being thin and highly flexible to conform closely to the shape of an irregular surface, the other of the sheets being adapted to be the top and being provided with a water aperture, and water in liquid and/or solid form in the enclosure.
By still another aspect of this invention, a method is provided for forming an outdoor natural ice rink which includes the steps of: (l) spreading out, at the site where the ice rink is to be formed, an expendible mould comprising a pair of sheets of substantially similar shape, the peripheral edges thereof being either integral or sealed to one another to form a water-tight enclosure, the sheets being formed of a synthetic thermoplastic material, one of the sheets being water-tight and adapted to be the bottom, and being thin and highly flexible to conform closely to the shape of an irregular surface, the other of the sheets being adapted to be the top, and being provided with a water inlet aperture; (2) filling the mould with water; (3) allowing the water to freeze to ice; and (4) removing the top sheet, thereby leaving an exposed, substantially flat ice surface.
GENERAL DESCRIPTION OF THE INVENTION The sheet material used in producing the expendible mould of one aspect of this invention is formed of a synthetic thermoplastic polymer, for example a polyolefin polymer, e.g. polyethylene or polypropylene. The polyolefin sheet should'be quite thin, i.e. of the order of 0.001 0.005 inch, e.g. 0.003 inch. It has been found that particularly advantageous results accrue where there is used a polyethylene polymer of the type having a molecular weight in excess of ten thousand. A sheet of this type has various highly desirable characteristics. Firstly, it is tough and highly flexible so that when it is filled with water which is to be frozen to form the ice, it will conform to local irregularities in the surface on which it is located. Thus, if it is placed on a lawn, it will conform to tufts of grass, stones or other irregularities without being broken or cut. Polymers of the type just mentioned have the property of remaining highly flexible down to temperatures below those ever encountered under conditions of ice skating. In fact, they remain flexible and tough at temperatures as low as --100F. Furthermore, they are impervious to water so that water should not enter pores and freeze, thereby causing cracking of the sheet. Another highly important property is that of no transmission of sunlight which appears necessary even in freezing weather to prevent killing of a lawn. It has been found that when such a rink is produced on a lawn during the winter, after removal following the end of freezing weather, the grass which has been covered has been unaffected and will continue to grow during the spring. Mechanical damage to the grass by crushing is also avoided. At the time the expendible mould is placed in position and filled with water, the flexibility of the sheeting produces an evening-out of pressure and when freezing occurs, the rigid ice spreads whatever pressure exists over extended areas so that there is no undue pressure of crushing type exerted locally.
Due to the fact that the radiation from sunlight is transmitted to the ground while the sheeting has good insulating properties, it has been found that the ice, once frozen, tends to remain frozen over more extended periods than is normally the case when freezing occurs in a shallow pond. In other words, temporary thawing temperatures will, unless of extended duration, result in less melting of the ice than would occur if the ice were in direct contact with the ground.
While other plastic sheeting material may be used, it is desirable to use sheeting having properties equivalent to those just mentioned which characterize the polyethylene polymers.
The sheeting need not be continuous since a large sheet may be readily built up by joining together several small sheets, for example, by welding through heat, chemical combinations of the same or other means. The sealing provides joints which are impervious and consequently, rinks in accordance with the invention may be provided up to any desired area. In fact, certain of the peripheral edges of the top and bottom sheets are sealed together to form the expendible mould.
DESCRIPTION OF THE DRAWINGS Brief Description of the Drawings In the accompanying drawings,
FIG. 1 is a top plan view of an expendible mould according to one aspect of this invention, filled with water in frozen ice form;
FIG. 2 is a section along the line IIII of FIG. I;
FIG. 3 is a perspective view of a final skating rink produced by the method of another aspect of this invention;
FIG. 4 is a top plan view of another variant of an expendible mould according to an aspect of this invention, with no water therein;
FIG. 5 is a section along the line /--V of FIG. 4;
FIG. 6 is a perspective view, partly broken away, ofa combination according to yet another aspect of this invention; and
FIG. 7 is a vertical cross-sectional view of yet another aspect of this invention.
DETAILED DESCRIPTION OF THE DRAWINGS Turning to FIGS. 1, 2 and 3, the expendible mould 10 of this aspect of this invention includes an upper sheet 11 and a lower sheet 12 of a polyolefin polymer, sealed together at their marginal side edges l3, 14. The upper sheet 11 is provided with a water inlet aperture 15.
As seen more clearly in FIGS. 2 and 3, the bottom sheet 12 follows the uneven contours of the surface upon which it rests. In the embodiment shown in FIG. 2, the bottom sheet 12 rests directly on the ground 16, while in the embodiment shown in FIG. 3, the bottom sheet 12 rests on a ground cover of snow and/or ice 17 over the ground 16. As seen more clearly in FIG. 3, when the top sheet 11 is removed, a substantially flat, smooth ice surface 18 is provided.
FIGS. 4 and 5 show the embodiment when the expendible mould is not rectangular in shape. As shown in FIGS. 4 and 5, the expendible mould is circular in plan (although any other geometrical shape may be used) and includes circular top sheet 20 and circular bottom sheet 21, with the circumferential edge 22 of top sheet 20 being heat-sealed to the circumferential edge 23 of bottom sheet 21. A space 25 is provided between the top sheet 20 and the bottom sheet 21 for placement of water therein, through water inlet aperture 24.
The combination shown in FIG. 6 includes a top rectangular sheet 30 and a bottom rectangular sheet 31, heat-sealed at their marginal side edges 32. The top sheet 30 is provided with a water inlet filler opening 33, as well as with a plurality of small holes or perforations 34 to allow trapped air to escape as the enclosure is being filled with water. The water previously admitted to the enclosure provided between top sheet 30 and bottom sheet 31 is in the form of ice 35. It will be observed that the top surface 30 is flat to provide a smooth, substantially flat ice surface 36, while the bottom sheet 31 follows the contours of the ground 16.
In the embodiment shown in FIG. 7, the rectangular expendible mould 10 includes a top sheet 40 and a bottom sheet 41 which are heat-sealed together at their marginal side edges 42, 43. Top sheet 40 includes filler opening 44. The two joined rectangular sheets are rolled together into a spiral 45, to facilitate the handling of large size expendible moulds. It will be evident that expendible moulds in various sizes may be sold to provide natural ice skating rinks of various sizes.
FURTHER ADVANTAGES OF THE INVENTION During the period of use the ice surface may be maintained merely by spraying additional water onto the ice surface by means of a hose, and finally, when the rink is to be removed, the water may run off and/or be permitted to evaporate or the ice melts.
The present invention also now provides a means of making a large flat ice surface with only one flood of water. It does not require the use of rink boards and the like. Furthermore, it does not require any preparation of the surface of the area regardless if the condition is bare, snow-covered, level, uneven, or sloped.
The invention also provides a method wherein water is completely contained in a totally enclosed flexible mould, sealed on all edges, which is spread over any outdoor area, filled with water through an opening in the upper surface until the water has covered the entire area, and left in temperatures below 32 Fahrenheit until frozen, after which the upper surface is removed leaving a flat usable ice surface over the entire area. Occasional light flooding will be required after the ice surface has been used in order to maintain a smooth finish.
The bottom layer of the mould can be opaque to protect the grass from any possible damage normally caused by sunlight. The bottom layer can have designs or markings placed or printed thereon, which can be seen through the ice for use with games played on the ice, or the top layer can have markings to be left imprinted in the ice after the water has frozen and the top layer of plastic or polyethylene is removed.
The final shape of the mould after it is filled and the water frozen is somewhat the same as a pillow. The edges are curved; the bottom follows the contours of the ground; the top surface is perfectly flat and smooth over the entire area; and the ice becomes solid with substantially no air pockets.
From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions. Consequentl% such changes and modifications are properly, equita ly, and intended to be, within the full range of equivalence of the following claims.
1. A mould for forming an ice skating surface, said mould when used once, being thereafter destroyed, said mould having a bottom and top comprising:
a pair of sheets of polyethylene having a thickness in the range of 0.001 to 0.005 inches of substantially similar shape, the peripheral edges thereof being either integral, or sealed to one another, to form a water-tight enclosure,
one of said sheets being water-tight and being the bottom of said mould, and being thin and highly flexible to conform closely to the shape of an irregular surface;
the other of said sheets being the top of said mould and being provided with an unsealed water inlet aperture for the free, unhindered entry into, and exit from, the mould of water and including a plurality of further apertures to permit the escape of entrapped air as the mould is being filled with water;
thereby to provide a fillable mould having a bottom surface conforming to the contour of the surface upon which the mould rests, and an upper mould surface defined by the inside face of the top;
the mould being destroyed by tearing off the top sheet after the mould has been filled with water and then frozen, the torn top sheet thereafter being removed in order to leave a moulded exposed, substantially uniform and flat ice skating surface.
2. The mould of claim 1 in rectangular form.
3. The mould of claim 2 rolled up upon itself, so that, upon unrolling, the mould is placed in water-receiving condition, with the bottom conforming to the shape of an irregular surface upon which it rests.
4. The mould of claim 2 folded upon itself, so that, upon unfolding, the mould is placed in water-receiving condition, with the bottom conforming to the shape of an irregular surface upon which it rests.
5. In combination, an enclosure including a pair of sheets of substantially similar shape, the peripheral edges thereof being either integral or sealed to one another to form a water-tight enclosure, the sheets being formed of a synthetic thermoplastic material, one of the sheets being water-tight and adapted to be the bottom, and being thin and highly flexible to conform closely to the shape of an irregular surface, the other of the sheets being adapted to be the top, and being provided with a water inlet aperture, and including a plurality of further apertures in the top to permit the escape of entrapped air as the enclosure is being filled with water and water in liquid and/or solid form in the enclosure.
6. The combination of claim 5 wherein the H 0 is in ice form.
7. The combination of claim 6 wherein the top sheet is removed, thereby leaving an exposed substantially flat ice surface.
8. The combination of claim 5 in rectangular form and formed of polyethylene having a thickness in the range of0.00l to 0.005 inches.