US20170164675A1

US20170164675A1 - Temperature-adjusting hat

Info

Publication number: US20170164675A1
Application number: US14/967,666
Authority: US
Inventors: George Buchert
Original assignee: Individual
Current assignee: Individual
Priority date: 2015-12-14
Filing date: 2015-12-14
Publication date: 2017-06-15

Abstract

A temperature-adjusting hat, having a hat having an inside for accommodating a head and an outside, a thermoelectric couple having a first side and a second side having a temperature differential between the first and second sides, and wherein the first side is positioned near the inside of the hat, a power source connected to the thermoelectric couple, and one or more heat pipes connected to the second side, extending over the outside of the hat, wherein the one or more heat pipes has a constant temperature along a length. The hat may have a heat wicking layer in communication with the one or more heat pipes, configured to distribute a temperature from the heat pipes across the outside of the hat. The heat-wicking layer may be graphene or pyrolitic graphite. The heat-wicking layer may be copper sheeting or aluminum, and the first side is positioned to contact a forehead.

Description

BACKGROUND OF THE INVENTION

1. Field of Invention
The present invention relates to the field of temperature adjusting garments such as hats, and garments that cool the wearer in particular.
2. Description of Related Art
There is a desire for humans to maintain a relatively constant temperature despite changes in the temperature of the environment. Typically, humans adjust the temperature of their surroundings by fans, transferring skin heat and evaporating perspiration, air conditioners and heaters that change the actual temperature in the environment), and these require relatively confined spaces, such as the interior of a building, to provide meaningful benefits. There are some heating garments that heat a wearer when outdoors, especially in extremely cold environments like the Arctic or Antarctic. However, there is little to cool a wearer in an extremely hot environment.
The human body transfers about ⅓ of heat transferred through the head, mainly as the head remains uncovered more than other body parts. A hat, such as a baseball cap, helps to maintain the head's temperature, particularly when it has a sunshade. However, this help is limited particularly in hot and humid environments.
Cold compresses may be applied to the head when undergoing chemotherapy in order to reduce hair loss associated with the treatment. In addition, cold compresses may be applied to the head to reduce migraines. However, cold compresses are not easily available, with a need for a refrigerator and a substance having a high thermal coefficient to remain cold while the compress is applied. In addition, ice compresses are messy and may melt into water.
There are many cooling products, especially cooling vests that cool using liquids that freeze/melt at temperatures above the freezing temperature of water (0 C.). These liquids are commonly known as PCMs or Phase Change Materials. These materials are cooled until they are frozen and are then placed in garments contacting the user's skin. As they melt, they pull heat from the user. The advantage over ordinary ice is that the higher frozen temperatures are not as frigid and unpleasant as 0° C. ice.
These are very common solutions for people with MS or other diseases where body temperatures need to be regulated to avoid extreme side affects of warm temperatures, which may result in death.
PCM vests, hats, and other garments are also used by outdoor workers such as roofers. These vests are expensive and are bulky and awkward in appearance. They also require a refrigeration source in order to freeze the materials prior to use. Once the material melts, the product loses its cooling properties until it is frozen again.
Another portable cooling device is a compressed air suit that is connected to an air compressor via a pneumatic tube. This is common in mining, in attic insulation work, and in other extremely hot environments. A further cooling product for an outdoor individual use is the cooled water-circulating suit. These suits have tubes that circulate water that is cooled and pressurized via a portable compressor that the user carries with him. These are common in NASCAR and other racing environments.
However, such products are not practical for cooling those seeking relief on a hot day. The ability to provide cooling to the end user in a lightweight, silent form that is all but invisible to an observer is what is hoped will bring portable, individual cooling to the public. Due to cultural traditions, the public is not going to confidently wear bulky, wet, noisy, and noticeable garments. This invention provides a degree of cooling in a form factor that can seamlessly blend into the garment culture of today without drawing unwanted attention or focus.
Therefore, it is desirable that a hat may be used for cooling the body while the wearer spends time out of doors, or to immediately provide cold compresses to the head when the wearer is undergoing chemotherapy or migraine treatment, without the need for refrigeration equipment, wherein the hat is small and portable and may blend into normal society.

SUMMARY OF THE INVENTION

A temperature-adjusting hat, having a hat having an inside for accommodating a head and an outside, a thermoelectric couple having a first side and a second side having a temperature differential between the first and second sides, and wherein the first side is positioned near the inside of the hat, a power source connected to the thermoelectric couple, and one or more heat pipes connected to the second side, extending over the outside of the hat, wherein the one or more heat pipes has a nearly constant temperature along a length.
The hat may have a heat wicking layer in communication with the one or more heat pipes, configured to distribute a temperature from the heat pipes across the outside of the hat. The heat-wicking layer may be graphene or pyrolytic graphite. The heat-wicking layer may be copper or aluminum sheeting or foil, and the first side is positioned to contact a forehead.
The power source may be a battery or one or more solar cells. The power source may be connected to the thermoelectric couple by a USB connection or other DC power source format. The first side may have an insulated covering, and the insulated covering may be cloth or other insulating material such as aerogel or neoprene. There may be a temperature control connected to the thermoelectric couple. A power regulator may be between the power source and the thermoelectric couple.
The hat may have a microcontroller connected to the thermocouple and configured to regulate temperature by switching the thermocouple on and off, and a heat fuse may be present to interrupt power to the thermocouple if a certain temperature is exceeded.
Thermocouple may further comprises a magnetic coupler attached by thermal adhesive, and wherein each heat pipe further comprises a magnetic coupler attached by thermal adhesive, wherein the thermocouple and heat pipes are connected magnetically.
A method of connecting a thermocouple to a heat pipe is disclosed, comprising the steps of adhering a thermally-conductive magnet to the thermocouple using a thermal adhesive, adhering a thermally-conductive magnet to the heat pipe using a thermal adhesive, and magnetically connecting the thermocouple and heat pipe. The magnets may have a mirror finish. There may also be a step of applying thermal grease to the magnets before connecting them.
The foregoing, and other features and advantages of the invention, will be apparent from the following, more particular description of the preferred embodiments of the invention, the accompanying drawings, and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, the objects and advantages thereof, reference is now made to the ensuing descriptions taken in connection with the accompanying drawings briefly described as follows.

FIG. 1 is a perspective view of the cooling hat, according to an embodiment of the present invention; and

FIG. 2 is a circuit diagram of the components of the cooling hat, according to an embodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Preferred embodiments of the present invention and their advantages may be understood by referring to FIGS. 1-2, wherein like reference numerals refer to like elements.
With reference to FIGS. 1 and 2, a hat 2 has a cooling system therein. Although a baseball cap is depicted, any style of hat may be used for the cooling hat, with or without a brim. The cooling system comprises a battery 5 that provides power to a thermoelectric couple 8 (also known as a TEC or Peltier) through a USB or other wired connection 10. The USB connection may be made with a connection jack 12. When power is applied to the thermoelectric couple 8, a temperature differential is created, wherein a first side facing the forehead becomes a cold side 15 while a second side facing the exterior of the hat becomes a hot side 18 (shown in FIG. 2). The hot side 18 of the TEC is connected to one or more heat pipes 20 extending over the surface of the hat 2, which evenly and almost instantaneously distributes the heat from the hot side 18 across the length of the heat pipes 20. The heat pipes 20 are connected to a heat wicking layer 23 such as copper sheeting, graphene or pyrolytic graphite, an ultra-thin carbon film membrane, distributed across the body of the hat to further remove and disperse the heat from the heat pipes and to eliminate hot spots. The heat is nearly instantaneously distributed across the heat pipes, and the wicking layer 23 further distributes the heat, to draw heat away from the heat pipes 20 to reduce hot spots and increase surface area for heat transfer to the environment. In one embodiment the wicking layer is sandwiched between layers of fabric 25 to provide fashionable styles and to protect the wicking layer and heat pipes from wear and tear, and provide insulation to reduce the impact of any hot zones on the wearer.
Outside of heat dissipation, mating a TEC to its heat sink, namely heat pipes and heat wicking layer, which is important on both sides but vital on the hot side, is the most important action in this field of science. There are 3 commonly used methods, namely 1) soldering the TEC to the heat sink, wherein a pre-tinned TEC is required; 2) the application of mounting hardware, such as spring loaded screws, and thermal grease or other thermal interface material; and 3) the use of thermal adhesive, which is an adhesive having a higher thermal conductivity than conventional glue. This third option is often a permanent connection as the glue is strong enough to potentially cause damage to the TEC if it is removed.
Surfaces contacting a TEC are often ground to as close to a mirror finish as is economical to produce the closest mating fit. However, no matter how true a surface is there will be microscopic pits in the mating surfaces. Given that air has an extremely low thermal conductivity, these pits create unwanted air pockets between the TEC and its mating surfaces, potentially reducing thermal efficiency. Such surface pits may be minimized by applying a Thermal Interface Material such as thermal grease, which can vary widely in its thermal conductivity, in between a TEC and a mating surface. TECs need to be mounted and secured with the appropriate mounting pressure as well as with an appropriate TIM in order to maximize the contact area with the heat sink of the system. A preferred embodiment uses a high quality thermal adhesive to bond the TEC and the heat pipes, providing both a high bonding and thermally conductive interface to the system.
A fourth mounting system for the thermocouple-heat pipe connection overcomes a major limitation of the aforementioned thermal adhesive, namely that once attached with the thermal adhesive, the bond is generally permanent and cannot be removed without damaging the TEC and the heat sink mounting surfaces. Presently, an easy method to disassemble a TEC system that also includes a thermally conductive TIM does not go behind using spring-loaded screws and thermal grease. This generally requires the use of screwdrivers and has the additional drawback of additional parts, such as screws, that need to be tracked and purchased.
This invention exceeds three major TEC mounting requirements: 1) Smooth Mounting Surfaces; 2) Appropriate Mounting Pressure; and 3) Appropriate TIM material.
This method involves mounting thin, yet strong, magnetic pieces that conform to the size of the TEC. These magnets are then firmly secured to both the TEC and the heat sinks via a secure thermal adhesive. There are many magnets that have a “mirror-like” finish that provide an ideal mounting surface for this system. Also magnets are available in varying strengths so that any mounting pressure can be provided magnetically. Lastly, an extremely small amount of commonly found thermal grease can be applied by the end user prior to attachment.
Since both the TEC and the heat sink will be mounted with opposing magnets, the assembly requires no tooling, hardware, or service skills. The heat sink can be simply slid off of the TEC and another can be applied by placing it anywhere within the magnetic pull of the TEC. The two parts will snap together easily. These strong, thin and thermally conductive magnetic pieces allow for an interchangeable system of TEC heat sink options. The novel TEC attachment method results a secure mounting system, the use of a thermally conductive TIM, and can be effortlessly disassembled/reassembled by any end user. This allows for the use of multiple cooling band options, for example contact bands of various shapes, sizes, colors and cooling capacities for example, and can be replaced out in order to conform to the needs of the end user.
In order to bond the hot side 18 of the TEC with the heat pipes 20, thin copper sheet metal shims are glued to the TEC. The heat pipes are then soldered to the copper shims. Soldering has a higher thermal conductivity coefficient than thermal adhesive, and also provides a stronger bond.
The heat pipes are not attached directly to the TEC as it is optimal to have a larger contact area than the TEC. A copper shim between the TEC and the heat pipes allows for a greater contact area with any shape that is required.
When the hat is worn, the cold side 15 of the TEC abuts against the wearer's forehead, or other parts of the wearer's skin, to remove excess dermal heat into the hot side, to be distributed and “wicked” away from the body. In an embodiment, the cold side 15 remains at about 3° C.-5° C., and provides a cooling effect as heat is absorbed from the skin of the wearer. The heat generated by the hot side 18 is distributed throughout the hot side 18 and along the heat pipes 20 of the hat 2.
The amount of heat separation of the TEC may be controlled by a temperature control 28. In one embodiment, the temperature control 28 regulates voltage or current to the TEC and is positioned between the battery and the TEC. In an embodiment, the temperature control 28 may consist of a wheel that adjusts a mechanical resistor, and in another it may be adjusted electronically, through a switch, or remotely, through a wireless network and a smartphone app, using a microcontroller. In one embodiment the system is powered by a rechargeable battery 5 that is removably connected by a USB connection. An internal rechargeable battery 27 may be present to power the system. Other standardized or proprietary connections may be used to connect the battery 5 to the system.
The system may use a microcontroller 32 to monitor the heat and cold of the system, and turn the system temporarily off when the TEC or another part of the hat stabilizes at a certain temperature, or cycle the power to conserve energy usage and permit the system to last longer on a given battery charge.
The human nervous system does adjust for extreme temperature differentials over time, and the cold feeling of a cold compress does diminish with time. Just as an icepack or wading into cool water feels extremely cold during the initial contact, this perception decreases with time. The actual temperatures may not change at all, but the nerves become “used” to the cold and do not transmit such a high degree of cold sensation to the brain. In order to counteract some of these affects, the invention could be placed on a timer. After a predetermined set of time, the hat will turn off for another predetermined set of time. This will prevent the user becoming acclimatized to the cooling sensation of the cold side of the TEC. Just as the nervous system is about to adjust, the cold compress is allowed to warm up. Then just as the cold sensation system of the body is reset, the hat is turned on again to cool. This system of turning the hat on and off can be programmed around the specific sensation formulas of each individual, i.e. custom set by each individual. While not providing any more cooling from a energy perspective (it will actually be less,) it does provide a substantial increase in the mental sensation of cooling to the user's brain.
This system can be programmed to any formula or turned off altogether depending on the wishes of the end user.
To prevent overheating of the TEC, a fuse may be present to temporarily decouple the power to the TEC, to prevent an overheating condition and prevent the hat 2 from becoming a potential fire hazard or source of burns for users.
Another mechanism of controlling the impact of the cold side on the forehead is an insulator material 30, such as linen or other moisture-absorbent material, covering the cold side, or a gel encased between the cold side and the skin to permit the cold to permeate through slowly.
A heat pipe is a closed evaporator-condenser system consisting of a sealed, hollow tube whose inside walls are lined with a capillary structure or wick. Thermodynamic working fluid, with substantial vapor pressure at the desired operating temperature, saturates the pores of the wick in a state of equilibrium between liquid and vapor. When heat is applied to the heat pipe, the liquid in the wick heats and evaporates. As the evaporating fluid fills the heat pipe hollow center, it diffuses throughout its length. Condensation of the vapor occurs wherever the temperature is even slightly below that of the evaporation area. As it condenses, the vapor gives up the heat it acquired during evaporation. This effective high thermal conductance helps maintain near constant temperatures along the entire length of the pipe, so as to instantaneously disperse and distribute heat.
Attaching a heat sink to a portion of the heat pipe makes condensation take place at this point of heat transfer and establishes a vapor flow pattern in the evaporating fluid. Capillary action within the wick returns the condensate to the evaporator (heat source) and completes the operating cycle. This system, proven in aerospace applications, transmits thermal energy at rates hundreds of times greater and with a far superior energy-to-weight ratio than can be gained from the most efficient solid conductor.
After turning on the thermoelectric couple, the hot side heats quickly and the cold side cools quickly. If the heat is not removed, the TEC quickly reaches stasis. Therefore, it is important for the heat to be removed from the hot side through the heat pipes.
The orientation of the TEC may be reversed to create a heating hat. The hot side heats the heat of the wearer and the cool side is connected to heat pipes and a wicking layer spread on the outside of the hat. In the embodiment of a heating hat, the hat is insulated to retain the warmth within the hat. The cool hat may be made to heat by reversing the current on the TEC, and, in an embodiment, inserting one or more resistors surrounded by thermal pads and conductive foil in order to spread the heat and provide warmth over a larger area. When the warming feature is activated the resistors will receive power and provide heating in select locations inside the hat, however the resistors will not receive power in cooling mode, as the resistors can only warm and not cool. The warming resistors may be coupled to a thermal fuse in order to regulate their heat production and prevent uncomfortably warm temperatures for the user. Insulation around the cold side heat pipe is essential. Without it the system will have a dramatically lower cooling potential.
Insulation known in the art may be used, such as aerogel insulation, which is the insulation with the lowest thermal conductivity rating outside of a vacuum. This material is extremely lightweight and thin, although it is rather expensive. A wide array of insulators could be used depending on cost considerations, the requirement for breathability and the weight and compactness of the insulation. Thermal conductivity is the key variable.
In another embodiment, the TEC provides temperatures of less than 0° C. and induces a phase change in a slender container of a substance, such as water, adjacent thereto, changing the water from liquid to solid. Phase changes have the advantage of retaining more heat energy than simply changing the temperature of the body of a substance within a single phase. Heat energy may be added or removed from the substance, yet the temperature will not change until the phase change is complete.
The present invention is not only applicable to a hat, but any garment that has a smaller surface for applying cold and a larger surface for dissipating heat.
The invention has been described herein using specific embodiments for the purposes of illustration only. It will be readily apparent to one of ordinary skill in the art, however, that the principles of the invention can be embodied in other ways. Therefore, the invention should not be regarded as being limited in scope to the specific embodiments disclosed herein, but instead as being fully commensurate in scope with the following claims.

Claims

I claim:

1. A temperature-adjusting hat, comprising:

a. a hat having an inside for accommodating a head and an outside;

b. a thermoelectric couple having a first side and a second side having a temperature differential between the first and second sides, and wherein the first side is positioned near the inside of the hat;

c. a power source connected to the thermoelectric couple; and

d. one or more heat pipes connected to the second side, extending over the outside of the hat, wherein the one or more heat pipes has a constant temperature along a length.

2. The temperature-adjusting hat of claim 1, further comprising a heat wicking layer in communication with the one or more heat pipes, configured to distribute a temperature from the heat pipes across the outside of the hat.

3. The temperature-adjusting hat of claim 2, wherein the heat-wicking layer is graphene.

4. The temperature-adjusting hat of claim 2, wherein the heat-wicking layer is pyrolytic graphite.

5. The temperature-adjusting hat of claim 2, wherein the heat-wicking layer is copper sheeting.

6. The temperature-adjusting hat of claim 2, wherein the heat-wicking layer is aluminum sheeting.

7. The temperature-adjusting hat of claim 1, wherein the first side is positioned to contact a forehead.

8. The temperature-adjusting hat of claim 1, wherein the power source is a battery.

9. The temperature-adjusting hat of claim 1, wherein the power source is connected to the thermoelectric couple by a USB connection.

10. The temperature-adjusting hat of claim 1, wherein the first side has an insulated covering.

11. The temperature-adjusting hat of claim 10, wherein the insulated covering is selected from the group consisting of cloth, neoprene and aerogel.

12. The temperature-adjusting hat of claim 1, further comprising a temperature control connected to the thermoelectric couple.

13. The temperature-adjusting hat of claim 1, further comprising a power regulator between the power source and the thermoelectric couple.

14. The temperature-adjusting hat of claim 1, further comprising a microcontroller connected to the thermocouple and configured to regulate temperature by switching the thermocouple on and off.

15. The temperature-adjusting hat of claim 1, further comprising a heat fuse configured to interrupt power to the thermocouple if a certain temperature is exceeded.

16. The temperature-adjusting hat of claim 1, wherein the thermocouple further comprises a magnetic coupler attached by thermal adhesive, and wherein each heat pipe further comprises a magnetic coupler attached by thermal adhesive, wherein the thermocouple and heat pipes are connected magnetically.

17. A method of connecting a thermocouple to a heat pipe, comprising the steps of:

a. adhering a thermally-conductive magnet to the thermocouple using a thermal adhesive;

b. adhering a thermally-conductive magnet to the heat pipe using a thermal adhesive; and

c. magnetically connecting the thermocouple and heat pipe.

18. The method of claim 17, wherein the magnets have a mirror finish.

19. The method of claim 17, further comprising the step of applying thermal grease to the magnets before connecting them.