US3748664A

US3748664A - System for maintaining acceptable environmental conditions in an indoor swimming pool enclosure

Info

Publication number: US3748664A
Application number: US00207154A
Authority: US
Inventors: A Morita
Original assignee: Sony Corp
Current assignee: Sony Corp
Priority date: 1971-12-13
Filing date: 1971-12-13
Publication date: 1973-07-31
Anticipated expiration: 1990-07-31

Abstract

A buoyant sheet material and apparatus utilizing the material are disclosed for preventing evaporation of water in an indoor swimming pool when the pool is not in use. The sheet material is formed with a layer of buoyant foamed plastic material and a thinner layer of water-impervious plastic material and it is wound on a roll rotatably mounted adjacent one side of the pool. When the pool is not in use, the sheet material is drawn from the roll and placed on the surface of the water in the pool to prevent evaporation of the water and to thereby maintain a relatively low humidity in the pool enclosure.

Description

United States Patent 1 Morita [111 3,748,664 [451 July 31,1973

1 1 SYSTEM FOR MAINTAINING ACCEPTABLE ENVIRONMENTAL CONDITIONS IN AN INDOOR SWIMMING POOL ENCLOSURE [75] Inventor: Akio Morita, Tokyo, Japan [73] Assignee: Sony Corporation, Tokyo, Japan [22] Filed: Dec. 13, 1971 [211 App]. No.: 207,154

Primary Examiner-Henry K. Artis Attorney-Lewis H. Eslinger et al.

[57] ABSTRACT Abuoyant sheet material and apparatus utilizing the material are disclosed for preventing evaporation of water in an indoor swimming pool when the pool is not in use. The sheet material is formed with a layer of buoyant foamed plastic material and a thinner layer of water-impervious plastic material and it is wound on a roll rotatably mounted adjacent one side of the pool. When the pool is not in use, the sheet material is drawn from the roll and placed on the surface of the water in the pool to prevent evaporation of thewater and to thereby maintain a relatively low humidity in the pool enclosure.

6 Claims, 5 Drawing Figures The present invention relates to a device for preventing evaporation of water from a pool and in particular to a sheet material which is adapted to prevent evaporation of water from an indoor pool and any increase of humidity within the surrounding enclosure.

It is presently becoming more common for large apartment complexes and even individual home owners to have indoor swimming pools constructed for use by the residents. One problem which frequently arises with such pools is that the water within the pool evaporates and increases the humidity within the surrounding enclosures to extremely high, uncomfortable, and often intolerable levels. A number of mechanical systems have previously been proposed for eliminating this problem such as for example dehumidifiers and specialized air conditioning systems which are adapted to remove the excess moisture within the surrounding pool enclosure. However, such systems are relatively expensive, particularly for the individual home owner, and are subject to numerous mechanical breakdowns so that the problems which they seek to overcome still arise periodically. In addition to their own expense, such systems require additional space in the surrounding swimming pool enclosure, or alternatively, their own separate enclosure outside of the building. This additional enclosure itself is an additional expense, is often unattractive, and often occupies valuable space suitable for other purposes.

Accordingly, it is an object of the present invention to prevent evaporation of water in a swimming pool.

Yet another object of the present invention is to maintain a relatively low level of humidity within an indoor swimming pool enclosure.

Yet another object of the present invention is to prevent evaporation of water in an indoor swimming pool by an arrangement which is relatively simple and inexpensive in construction and durable in use.

In accordance with an aspect of the present invention, evaporation of water in a swimming pool, or other body of water, is prevented by placing a sheet of buoyant, water impervious material on the surface of the water when the pool is not in use. As is well known, evaporation of water occurs at the surface of a body of water which is in contact with the atmosphere. Molecules of water escape from the surface because of their kinetic energy and enter the atmosphere through the vapor layer at the surface of the water and thereby increases the moisture content and thus the relative humidity of the surrounding atmosphere. When this occurs in an enclosure, for example the enclosure or room surrounding an indoor swimming pool, the humidity of the pool surround increases substantially and makes the room uncomfortable. By placing the buoyant impervious sheet material of the present invention on the surface of the water when the pool is not in use, evaporation of the pool water is prevented and as a result, the moisture content of the air, (i.e. the humidity) in the pool surround is not increased.

2 layer. The foamed layer provides the buoyancy for the sheet and the water-impervious film material prevents water molecules from escaping from the surface of the water to the atmosphere. The sheet material is formed The material utilized to form the buoyant sheet of the I present invention comprises a layer of foamed buoyant 6 plastic material, preferably polyurethane, and a thinner layer of water-impervious plastic material, such as for example film polyurethane, laminated to the foamed with a slightly larger peripheral configuration than the swimming pool and is adapted to be wound on a roll for storage when the pool is not in use. The roll is rotatably mounted adjacent the swimming pool so that sheet material thereon is conveniently available for placement on the surface of the water when the pool is not in use.

In the illustrative embodiment of the invention, the

.roll is mounted in an enclosed casing which is adapted to be enbedded in the ground surrounding the pool so that it is out of view but still available for use. Automatic driving means may be provided for drawing the sheet material from the roll over the surface of the water and automatic return means may also be provided for rewinding the sheet material when the pool is to be used.

The above, and other objects, features and advantages of this invention will be apparent in the following detailed description of an illustrative embodiment thereof which is to be read in connection with the accompanying drawings, wherein:

FIG. 1 is a perspective view of pool partially covered by a buoyant sheet material for preventing evaporation of water in the pool, according to an embodiment of the present invention;

FIG. 2 is a sectional view of the pool and roll arrangement taken along line 2--2 of FIG. 1;

FIG. 3 is a plan view, partly in section, and with parts broken away, taken along line 3-3 of FIG. 2;

FIG. 4 is an enlarged sectional view of the sheet material utilized in an embodiment of the present invention; and

FIG. 5 is a partial sectional view, similar to FIG. 2, of another embodiment of the invention.

Referring to the drawings in detail, and initially to FIG. 1 thereof, it will be seen that a roll 10 of sheet material adapted to prevent evaporation of water in a pool, in accordance with an embodiment of the present invention, is positioned adjacent an indoor swimming pool 12, located within an enclosure or room 14. Roll 10 is contained within a casing 16 embedded in the pool surround 17 adjacent the end 18 of the pool. Casing 16, which may be formed of concrete, metal or the like, has an access hatch 19 and defines a chamber 20 in which the roll 10 is mounted. The latter is rotatably supported by its central shaft 21 on a pair of bearing blocks 22 to permit winding and rewinding of the sheet material 24 on the roll.

Sheet material 24 is formed of a flexible plastic laminate material which is buoyant and water impervious. This material is formed of a layer of foamed and inflated beads of polyethylene material, which are formed in a heat treating process into the layer 28. This layer provides buoyancy to the sheet material 24 and permits the material to float upon the surface of the water in the pool, as more fully described hereinafter. Sheet 24 also includes an upper layer 30 of waterimpervious material, preferably supplied as a film sheet of polyethylene, which is laminated to layer 28 by an adhesive or by a heat sealing process. Layer 28 is preferably between L5 to 2.0 mm. thick and film layer 30 is preferably 0.03 mm. thick. Thus, sheet 24 is a very thin member and may be wound on central roll shaft 21 in a compact configuration so that a minimum amount an indoor swimming of room in the pool surround is required for the roll and casing 16.

In one embodiment of the invention the pool coping 32, surrounding pool 12, is provided with a slot 34 in the end 18 of the pool. Casing 16 includes a complementary slot 36 through which sheet 24, from roll 10, passes to the surface of the water in the pool. Slot 34 may be provided with a break roller 38 or the like in order to guide sheet 24 through the slot and to prevent it from engaging any sharp or angulated edges of the coping.

When the pool is not in use, it is desirable to cover the entire water surface in the pool to prevent escape of water molecules into the surrounding atmosphere and thereby avoid resulting increased humidity. In accordance with the illustrative embodiment of the invention, this is accomplished by providing the free edge 40 of sheet 24 with a cross bar 42 which is connected by a pair of pull ropes 44 to the sheaves 46. The latter are rigidly mounted on a winding shaft 48, which is adapted to be rotated by a drive motor 50, to wind ropes 44 onto the sheaves and thereby draw sheet 24 over the surface of the water. Motor 50, shaft 48 and sheaves 44 are contained within a second enclosure 52 embedded in the pool surround l7 adjacentthe end 54 of thepool, i.e., the end of the pool opposite end 18.

Casing 52 includes a slot 56 therein through which ropes 44 and the end 40 of sheet 24 pass when the sheet is extended. When the end 40 of sheet 24 is moved to a position adjacent shaft 48, the sheet fully covers the entire water surface area of the pool with sheet 24 lying over the edges 58 of the gutter 60 formed along the sides of the pool. The gutter is a conventional feature in most swimming pools which limits the depth of the water therein and which drains foreign material floating on the top of the water from the pool. Where such gutters are not provided, the ropes 44 may of course extend closely along the sides of the pool or in slots formed along the sides. In the event that the surface 62 of the water is below the level of coping edge 58, sheet 24, which is drawn loosely across the pool by motor 50 so that some slackness is permitted, will drop down and rest upon the surface of the water (FIG. 2).

Sheet 24 is formed in a configuration which is complementary to the configuration of the pool so that the entire water surface area of the pool will be covered by the sheet when in use. When the pool has an irregular shape, sheet 24 will have the same shape so that when it is fully extended it is completely complementary to the pool. Alternatively, a plurality of rolls may be utilized and they may be positioned, as would be clear to one skilled in the art, so as to cover the entire surface area of the irregularly shaped pool when they are extended. In any case, sheet 24 floats on the surface of the water and provides a barrier for the escape of moisture from the surface of the pool. As a result, water vapor from the surface of the pool cannot escape to the atmosphere and increase the humidity within enclosure 14 thereby is avoided.

It is noted, that while the present invention is described in conjunction with an indoor swimming pool, it is contemplated that the invention can be utilized with outdoor swimming pools or other bodies of water where it is desired to prevent evaporation or the accumulation of dirt and foreign material on the surface of the water.

When the pool is to be used, sheet 24 simply is rewound on roll 10. For this purpose a motor 64 is provided within enclosure 16 for rotating roll in a direction to rewind sheet 24 thereon. Motor 60 is provided with a conventional one-way clutch (not shown) so that it is not turned, and does not prevent unwinding of the sheet material, when sheet 24 is withdrawn from roll 10 by motors 50. In addition, in order to dry the sheet 24 as it is rewound, enclosure 16 may be provided with an elongated bore 66 having an upper flared discharge opening 68 adjacent the lower surface 70 of sheet 24 as it is rewound on roll 10. A supply of warm air, drying talc or the like, may, in one embodiment, be supplied from a source thereof through a supply hose 72 for discharge through bore 66 and application to the lower surface of the sheet as it is being rewound. In this manner, excess moisture on the lower surface of the sheet is evaporated by the warm air, or absorbed by the talc, so as to avoid formation of mildew on the sheet during storage. Upon completion of the rewinding operation, bar 42 is adjacent slot 34 so that it is completely out of view and away from the water surface whereby it does not interfere with the use of the pool and does not affect the appearance thereof.

In another embodiment of the invention, enclosure 16 may be provided with a slot 72 on its upper surface adjacent hatch 19, so'that sheet 24 passes through the opening 72' over the top edge 74 of the coping and thence onto the surface of the water in the pool. Bythis arrangement, the possibility of water entering the chamber 20 of enclosure 16 is substantially decreased.

In yet another embodiment of the present invention, which is useful with pools that have been previously constructed, roll 10 may be rotatably mounted on deck 17 surrounding the pool so that sheet 24 may be manuallywithdrawn from the roll. This may be done, for example, by two persons standing on either side of the roll, grasping the ends of pole 42, and drawing the sheet over the surface of the pool as they walk along its sides. In this embodiment, the roll may be provided with a hand crank to rewind the sheet material on the roll when the pool is to be used. This arrangement is the simplest and most inexpensive system for preventing evaporation of moisture from the pool and in addition is relatively simple to operate.

The present invention cooperates with the air conditioning system utilized for the pool surround or enclosure since it prevents evaporation of the pool water and thus assists in maintaining a relatively low humidity within the pool surround. Accordingly, the size of the air conditioning system need not be as large as heretofore required, and with less moisture in the air that must be removed, the system can operate more efficiently. In addition, the water within the pool remains at a warmer temperature so that no water heater or at least a much smaller water. heater than normal is required. It is well known that upon evaporation of water, the temperature of the water decreases because the energy consumed in expelling the molecules of water from the surface of the body of water reduces the total energy in the body of water and thus causes a decrease in its temperature. By preventing evaporation, the water within the pool does not lose this energy and thus is maintained at a relatively constant temperature.

Accordingly, it is seen that a relatively simple and inexpensive device is provided for maintaining a relatively low level of humidity within an enclosure for an indoor pool. The construction of the sheet material is advantageous in that a relatively thin and light buoyant material is provided to accomplish the purpose of the invention and as a result, the entire system is relatively compact and hidden from view so that the appearance of the pool surround is not encumbered and no operating equipment is exposed in an area adjacent the pool where a swimmer or other person using the pool could possibly trip over it. In addition, the sheet material has a high buoyancy factor since a substantial portion thereof is formed of foamed polyethylene material which is highly buoyant. Accordingly, there is little possibility for the sheet material to sink under the surface of the water even when an accumulation of moisture or objects from the pool surround fall upon its surface.

Although illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of this invention.

What is claimed is: i

l. A device for preventing evaporation of water in a pool when the pool is not in use comprising, a roll of buoyant water impervious sheet material adapted to be rotatably mounted adjacent the pool, said sheet material having the 'same general peripheral configuration of the pool with which it is to be used and being formed of a layer of buoyant foamed plastic material and a thinner layer of water impervious plastic material, whereby said material is adapted to be unrolled and placed on the surface of the water in the pool to prevent evaporation of the water when the pool is not in use.

2. The device as defined in claim 1 wherein said foamed plastic layer is formed of a foamed polyethylene and said impervious layer is formed of a film of polyethylene.

3. The device as defined in claim 2 including means for drawing said sheet material from the roll thereof over the surface of water in the pool.

4. The device as defined in claim 3 including means for rewinding said sheet material onto said roll prior to use of said pool.

5. The device as defined in claim 4 including an ena closure for said roll adapted to be embedded in the ground surrounding the pool and means rotatably mounting said roll in said, enclosure, said enclosure having an opening therein through which said sheet material may be wound and unwound on the roll.

6. The device as defined in claim 2 wherein said foam layer is between 1.5 and 2.0mm. thick and said film layer is approximately 0.03mm. thick.

Claims

1. A device for preventing evaporation of water in a pool when the pool is not in use comprising, a roll of buoyant water impervious sheet material adapted to be rotatably mounted adjacent the pool, said sheet material having the same general peripheral configuration of the pool with which it is to be used and being formed of a layer of buoyant foamed plastic material and a thinner layer of water impervious plastic material, whereby said material is adapted to be unrolled and placed on the surface of the water in the pool to prevent evaporation of the water when the pool is not in use.

5. The device as defined in claim 4 including an enclosure for said roll adapted to be embedded in the ground surrounding the pool and means rotatably mounting said roll in said enclosure, said enclosure having an opening therein through which said sheet material may be wound and unwound on the roll.