Background of the Invention: [0002] There have been many types of cooling garments developed in the prior art to try to reduce heat problems encountered by workers in hot environments. One type of garment incorporates thin tubes throughout the garment and uses cold water that is circulated through the tubes. Water is channelled through the inner tubing and then through a bucket of ice disposed outside the garment. Such garments require a mechanical pump to circulate the water from the tubing in the garment to the bucket that is exterior to the garment. Thus, the wearer of the garment must carry or somehow transport the bucket of ice, which is cumbersome and undesirable. As well, since the circulating water is melt water having a temperature approaching the melt temperature of the ice, it is difficult to maintain the water temperature at a suitable temperature.

[0003] A second type of garment uses either ice or dry ice inserted into pockets in the garment to provide cooling to the wearer the garment. Dry ice cooling garments utilize solid C02 that sublimates. However, because of the extreme low temperature of dry ice, insulation is required between the dry ice pockets and the wearer in order to prevent harmful contact between the dry ice and the wearer. This insulation has the effect of reducing the cooling effectiveness of the garment. As for garments using ice, they utilize an excessive amount of ice, the physical dimensions of which make the garment bulky.

[0004] A third type of garment is a combination of the first two. They comprise a solid refrigerant, such as dry ice or ice and an intermediate heat exchange fluid ; The fluid is circulated through tubular flow channels incorporated in the suit near the body. It is by means of this flowing fluid that the wearer of the garment is cooled. The heat transfer between the ice and the fluid is important for the safe functioning of the garment.

[0005] Another, but less used, design employs a pressurized fluid stored in a pressure vessel, which is flashed-off to provide the requisite cooling. Drawbacks include the weight of the pressure vessel and the potential for environmental air contamination since this type of system typically uses fluorocarbon refrigerants that are flashed and then expelled into the atmosphere where the worker is located.

[0006] The cooling systems disclosed in the prior art can be characterized as passive systems in that they do not use a circulating heat exchange fluid to enhance heat transfer. These systems therefore have relatively low heat transfer capabilities compared to active systems with circulating heat exchange fluids. For example, U. S. patent no. 4,033, 354 discloses a vest-like garment having an insulated front body panel and an insulated rear body panel attached together by shoulder straps. Fasteners, such as those known by the trademark Velcro@, are attached to the front body panel and the rear body panel such that the garment can be secured to the body of the wearer. A plurality of sealed waterproof bags filled with water is releasably attached to the inside of the garment. When the water in the bags is frozen, the garment cools the body of the wearer. A layer of absorbent fabric such as terry cloth is disposed between the inside surface of the bags and the wearer of the garment.

[0007] Another example of a passive system is U. S. patent no. 4,405, 348, which discloses a cooling system for heat protection suits that uses solid refrigerant positioned in a housing overlying a heat exchange surface. The solid refrigerant is separated from the surface by a flexible intermediate layer that is saturated with an intermediate liquid.

The fluid in the intermediate layer assures good heat transfer and transmission.

[0008] U. S. patent no. 4,856, 294 discloses a self-contained cooling vest made of lightweight material (e. g. nylon cloth) having an interior cross-section of double wall construction. The internal portion of the vest is comprised of a salable insulative pocket or liner having a thickness on the order of 1-2 inches. The internal portion contains a heat exchange material that changes phase from solid to liquid within a practical temperature range (e. g. 60-90 °F.). The cooling action of the vest operates to draw body heat away from the wearer in the course of the phase change of the heat exchange material from solid to liquid state. An optional outer layer of insulating foam material may be provided adjacent to the inner liner.

[0009] There, therefore, remains a need to provide a modular cooling device that can be incorporated into garments to provide better cooling to the wearer.

[0010] The disclosures of all patents/applications referenced herein are incorporated herein by reference.

Summary of the Invention: [0011] The present invention relates to a personal cooling device that includes a thermally insulated compartment, a heat exchanger and an ice pack. The heat exchanger comprises two sets of tubes with each set having one or more tubes, a heat exchange fluid in the tubes and a pump for circulating the fluid within the tubes.

[0012] In one aspect of the present invention, there is provided a modular cooling device that comprises: [0013] (a) a thermally insulated compartment; [0014] (b) a heat exchanger comprising: [0Ol5l (i) a first set of tubes comprising one or more first tubes arranged in a side-by-side relationship; [0016] (ii) a second set of tubes comprising one or more second tubes arranged in a side-by-side relationship, wherein the second tubes are in fluid communication with the first tubes; [0017] (iii) a heat exchange fluid in the first and second tubes; and [0018] (iv) a pump operatively connected to the first and second set of tubes for circulating the heat exchange fluid in the first and second tubes; [0019] (c) a power source for supplying electrical power to the pump; and [0020] (d) an ice pack in the compartment, [0021] wherein the first set of tubes is located in the compartment with the ice pack, and the second set of tubes is located outside the compartment such that the heat exchange fluid is cooled as it circulates in the first tubes and the heat exchange fluid is warmed as it circulates in the second tubes.

[0022] According to a second aspect of the invention, the first and second tubes are in a side-by-side spaced apart relationship and are surrounded by and sealed to a foil so as to maintain the first and second tubes in the spaced apart relationship. Preferably, the first tubes are integral with the second tubes. The device is adapted to be used in a garment, preferably a protective apparel such as a protective vest.

[0023] In a further aspect of the present invention, there is provided a method of providing cooling to a wearer of a garment, wherein the garment has an interior side adjacent the wearer, the method comprising the steps of: [0024] (a) providing a thermally insulated compartment on the interior side; [0025] (b) providing a cooling device, wherein the cooling device comprises : [0026] (i) a heat exchanger comprising: [0027] (A) a first set of tubes comprising one or more first tubes arranged in a side-by-side relationship; [0028] (B) a second set of tubes comprising one or more second first tubes arranged in a side-by-side relationship, wherein the second tubes are in fluid communication with the first tubes; [0029] (C) a heat exchange fluid in the first and second tubes; and [0030] (D) a pump operatively connected to the first and second set of tubes for circulating the heat exchange fluid in the first and second tubes; [0031] (ii)'a power source for supplying electrical power to the pump; and [0032] (iii) an ice pack in the compartment, [0033] (c) locating the first set of tubes in the compartment with the ice pack, and locating the second set of tubes outside the compartment and adjacent to the wearer; and [0034] (d) supplying power to the pump to cause the heat exchange fluid to circulate such that the heat exchange fluid is cooled as it circulates in the first tubes and the heat exchange fluid is warmed as it circulates in the second tubes to provide cooling to the wearer.

[0035] Numerous other objectives, advantages and features of the process will also become apparent to the person skilled in the art upon reading the detailed description of the preferred embodiments, the examples and the claims.

Brief Description of the Drawings: [0036] The preferred embodiments of the present invention will be described with reference to the accompanying drawings in which like numerals refer to the same parts in the several views and in which: [0037] Fig. 1 is schematic perspective view of a first embodiment of a modular cooling device of the present invention.

[0038] Fig. 2 is schematic cross-sectional view of the cooling device of Fig. 1.

[0039] Fig. 3 is a schematic perspective view of a second embodiment of a modular cooling device of the present invention.

[0040] Fig. 4 is schematic cross-sectional view of the cooling device of Fig. 3.

[0041] Fig. 5 is an illustration in perspective view of the sets of heat exchange tubes useful in the embodiments of Fig. 1 and Fig. 3.

[0042] Fig. 6 is a detailed end view of a cross section of the sets of heat exchange tubes of Fig. 5.

Detailed Description of the Preferred Embodiments: [0043] The preferred embodiments of the present invention will now be described with reference to the accompanying figures.

[0044] A preferred embodiment of the modular cooling device 10 of the present invention is shown in Fig. 1. The cooling device 10 includes a thermally insulated compartment 12 defined by walls 14. Walls 14 may be made of any suitable thermal insulating material, for example, insulating foam or bubble wrap laminated with aluminum foil.

[0045] Insulated compartment 12 is adapted to hold an ice pack 16, which contains a material that preferably has a freezing point in the range of-20°C to 10°C, and a latent heat of fusion in the range of 200 to 500 Joules/gram. Most preferably, the material is water, however other known suitable materials may be used. Examples of other materials include solutions of water and ethylene glycol, and water and sodium chloride.

[0046] Included in cooling device 10 is a heat exchanger consisting of a first set of tubes 18 comprising one or more first tubes arranged in a side-by-side relationship.

Preferably, the first tubes are spaced apart and parallel to each other and the first set of tubes 18 is surrounded by and sealed to a first laminated foil comprising at least one layer of metal and at least one polymer layer so as to maintain the first set of tubes 18 in the side-by-side relationship. A second set of tubes 20 is provided, which also comprise one or more second tubes arranged in a side-by-side relationship. Preferably, the second tubes are spaced apart and parallel to each other and the second set of tubes 20 is also surrounded by and sealed to a second laminated foil comprising at least one layer of metal and at least one polymer layer so as to maintain the second set of tubes 20 in the side-by-side relationship. One end of the second set of tubes 20 is in fluid communication with one end of the first set of tubes 18 by means of suitable manifolds 22 and 22' (not shown in Fig. 1) and connecting tube 24. The opposite ends of the second set of tubes 20 and first set of tubes 18 are also operatively connected to each other via manifolds 26 and 26'and connecting tubes 28 and 30 so as to be in fluid communication. A suitable pump 32 is provided for circulating a heat exchange fluid within the first and second set of tubes 18 and 20. A power source (not shown) is also provided for supplying power to the pump 32.

[0047] The first set of tubes 18 is located inside the compartment 12 adjacent to the ice pack 16, while the second set of tubes 20 is located outside the compartment 12. The heat exchange fluid is cooled as it circulates in the first set of tubes 18 due to heat transfer from the warmer heat exchange fluid to the colder ice pack 16. The solid ice in ice pack 16 is caused to melt as a result of this heat transfer. Similarly, the heat exchange fluid is warmed as it circulates in the second set of tubes 20 due to heat transfer from the warmer environment 34 to the colder heat exchange fluid. In a preferred aspect of the invention, the warmer environment 34 may be the body of a person, and cooling device 10 is located between the person's body and a garment 36 worn by the person. A suitable fastening device 38, such as Velcro@ strips may be provided to hold cooling device 10 to the inside of garment 36.

[0048] Compartment 12 and ice pack 16 are adapted such that the ice pack 16 is easily removable from and replaceable into the compartment 12. This allows the user three different options for freezing the material in the ice pack 16. First, the ice pack 16 can be removed from compartment 12 and placed into a freezer; second the entire cooling device 10 may be removed from the garment 36 and placed into a freezer; or third the entire garment 36, including the cooling device 10, may be placed in a freezer.

[0049] The heat exchange fluid should preferably be one that provides adequate heat transfer and one that does not freeze at temperatures above-20 °C so that the heat exchange fluid will not freeze when the cooling device 10 is placed in a freezer in order to freeze the material in the ice pack 16.

[0050] In a further embodiment, the first set of tubes 18 and the second set of tubes 20 each comprise at least two subsets of tubes. A controller, such as a valve, may be used to control and vary the flow rate of the heat exchange fluid circulated in each subset of tubes. This allows the user of the device greater flexibility in controlling the heat exchange rate in the insulated compartment 12 and in the second set of tubes 20.

[0051] In a preferred aspect of the present invention, garment 36 is a protective apparel, preferably a protective vest, such as protective suits worn by firefighters, chemical clean-up crews, etc.

[0052] Fig. 2 illustrates a cross-sectional view of the cooling device 10. Ice pack 16 is located in compartment 12, which is defined by the inside surfaces of thermally insulated walls 14. The first set of tubes 18 is disposed in compartment 12 between one wall 14'and the ice pack 16. A Velcro@ strip is adhesively attached to the outside surface of wall 14', and the Velcro@ strip may be removably fastened to the inside of a garment 36. The second set of tubes 20 is disposed outside compartment 12, and is in fluid communication with the first set of tubes 18 via connecting tube 24 and suitable manifolds. The second set of tubes 20 is in proximity to a relatively warm environment 34, such as a person's body, that is to be cooled.

[0053] Fig. 3 illustrates a second embodiment of the present invention. The cooling device of this embodiment comprises a compartment 40 defined by thermally insulated walls 42. An ice pack 44 is located in compartment 40. A first set of tubes 46 is disposed between the ice pack 44 and one of the walls 42'. A second set of tubes 48 is located at a position remote from the compartment 40. The second set of tubes 48 is in proximity to an environment 50 to be cooled. A further insulating wall 52 is adjacent the second set of tubes 48 to ensure more efficient cooling of the environment 50. A connecting tube 54 and suitable manifolds (not shown) cause the second set of tubes 48 to be in fluid communication with the first set of tubes 46. A heat exchange fluid is caused to circulate within the first and second sets of tubes 46 and 48 by a suitable pump (also not shown in Fig. 3).

[0054] The second embodiment of Fig. 3 is also shown in Fig. 4 where pump 56 is shown. The pump 56 is operatively connected to connecting tubes 58 and 60 for circulating the heat exchange fluid within the first and second set of tubes 46 and 48.

Connecting tube 60 is further connected to a suitable manifold 62 to be in fluid communication with the first set of tubes 46, and connecting tube 58 is connected to a suitable manifold 64 to be in fluid communication with the second set of tubes 48. A manifold 66 is provided at the other end of the second set of tubes 48 and is in turn connected to connecting tube 54. Similarly, a manifold (not shown) also connects the other end of the first set of tubes. 46 to connecting tube 54.

[0055] Fig. 5 and 6 illustrate the construction of the sets of tubes useful in the present invention. The sets of tubes preferably comprise a plurality of polymeric tubes 70 arranged in parallel and placed at least 1-1/2 tube diameters apart measured center-to- center. The tubes 70 are held in place by, surrounded by and sealed to a laminated foil 72. The foil 72 has two faces 74 and 76, face 74 facing toward the tubes 70, and face 76 facing away from the tubes 70. The foil 72 includes at least one layer of metal 78 with at least one polymer layer 80 on at least the side facing the tubes 70. The tubes 70 preferably have an inner diameter in the range of 0. 5mm to 10 mm and a wall thickness in the range of 0.05 mm to 0.3 mm, while the foil 72 has a total thickness preferably in the range of 0.05 mm to 0.25 mm and a total metal thickness preferably in the range of 0.002 mm to 0.1 mm. The number of tubes 70 in each of the first and second sets of tubes 18 and 20 is preferably from 5 to 20 tubes. Each of the tubes 70 may comprise one or more layers of polymer, and preferably the polymer is polyamide. Optionally, the diameters of the tubes 70 are all in one plane. Examples of such sets of tubes and of how to make such tubes are provided in U. S. published patent application nos.

20030094264 and 20030070752, the specifications of which are hereby incorporated in their entirety by reference.

[0056] A further aspect of the present invention is the provision of a method of cooling a wearer of a garment. The method includes the steps of providing a modular cooling device as described above, locating the first set of tubes in the compartment adjacent to the ice pack, and locating the second tubes outside the compartment and adjacent to the wearer of the garment. Power is then supplied to the pump such that the heat exchange fluid is circulated within the first and second set of tubes, and it is cooled as it circulates in the first tubes and it is warmed as it circulates in the second tubes to provide cooling to the wearer.

[0057] Although the present invention has been shown and described with respect to its preferred embodiments and in the examples, it will be understood by those skilled in the art that other changes, modifications, additions and omissions may be made without departing from the substance and the scope of the present invention as defined by the attached claims.