KOSHY, George (D2/1, Vipul MitraCHS, Pragati Nagar,Goregaon West,Mumbai 2, Maharashtra, 400 06, IN)
CLAIMS We claim:
1. A headgear that provides cooling / heating effect to the user / wearer comprising shell of preferably hard material defining cavities adapted to fit single or preferably plurality of cooling / heating module/s in the form of solid state thermoelectric heat pump means comprising thermoelectric module / chip / element, first thermally conductive means, second thermally conductive means wherein the said first thermally conductive means comprises of central substantially flat portion wherein the said thermoelectric module / chip / element is thermally bonded using thermally conductive material, plurality of stripe like elements of the first thermally conductive means radially protruding outwards wherein the portion away from the said central flat portion of the said elements of the first thermally conductive means is adapted to be thermally bonded using thermally conductive material to the mesh / disc that is distanced from the said flat portion;
a power source operably connected with the said thermoelectric module / chip / element; optional temperature control means for the said thermoelectric module / chip / element/s.
wherein part of the said second thermally conductive means protrudes from the exterior of the shell to be in contact with the ambient air; the said thermoelectric module / chip / element and the said first thermally conductive means are disposed in the interior of the headgear.
2. A headgear that provides cooling / heating effect to the user / wearer as claimed in Claim 1
wherein the said first thermally conductive means is in the form of stripe/s, disc or a combination thereof that is preferably flexible in nature and helps assume the shape of the head of the user/ wearer of the headgear and is placed inside the shell.
3. A headgear that provides cooling / heating effect to the user / wearer as claimed in Claims 1-2 wherein the said first thermally conductive means are attached below each other and radially projecting in a same plane to form a star like configuration.
4. A headgear that provides cooling / heating effect to the user / wearer as claimed in Claims 1-3 wherein the said first thermally conductive means is in the form of wired matrix structure laminated / coated with rubber / polymer / low conductivity based preferably flexible material.
5. A headgear that provides cooling / heating effect to the user / wearer as claimed in Claims 1-4 wherein the said first thermally conductive means is a lamina attached to the said thermoelectric module / chip / element.
6. A headgear that provides cooling / heating effect to the user / wearer as claimed in claims 1-5 wherein thermally conductive adhesive or thermally conductive medium like grease, pads, etc. is used alongwith adhesive or fastening mechanism to attach the said thermoelectric module / chip / element to the first and second thermally conductive means.
7. A headgear that provides cooling / heating effect to the user / wearer as claimed in claims 1-6 wherein the said first thermally conductive means in the form of a stripe / disc and mesh / disc is of metal and coated / laminated with polymer / rubber / low conductivity based preferably flexible material.
8. A headgear that provides cooling / heating effect to the user / wearer as claimed in Claim 1 wherein the said second thermally conductive means is a ribbed profiled extruded section, with ribs of rectangular, triangular or surface enhanced configuration.
9. A headgear that provides cooling / heating effect to the user / wearer as claimed in Claim 1 wherein the said second thermally conductive means is preferably a strip with pin like elements protruding out from a base and the pin cross-section could be oval, circular, rhombic, etc.
10. A headgear that provides cooling / heating effect to the user / wearer as claimed in claims 1-9 wherein there is provided a temperature control system comprising one or plurality of temperature sensing, measuring and optionally indicating means disposed inside the said headgear in connection with a voltage regulating means and the power source configured with the said solid state thermoelectric heat pump means.
11. A headgear that provides cooling / heating effect to the user / wearer as claimed in claims 1, 8, 9 wherein the said second thermally conductive means is provided with a selective coating or anodized.
12. A headgear that provides cooling / heating effect to the user / wearer as claimed in claims 1 -11 wherein the cooling / heating module in the headgear is adapted to removably receive quick release retractable wire mechanism so as to operably connect to the power source. |
"Headgear for Comfort"
Field of the Invention
The present invention relates to a headgear that provides cooling / heating effect to the user/ wearer.
Background of the Invention
Headgears are being used for various applications to protect the head of the user. A head covering of hard material, such as leather, metal, or plastic is worn by football players, firefighters, construction workers, motorcyclists, and others to protect the head. In any of the applications it is imperative that the wearer / user of the helmet is at a comfort level while wearing the headgear as most of the headgears cover the head that resists heat dissipation from the body. The problem further aggravates in hot and humid exterior conditions wherein most of the users tend to avoid using the headgear because of the discomfort.
Various attempts are made to overcome this problem. Review of the same is presented hereafter.
EP0115498 and US 4483021 patents disclose Thermo-Electric Cooled Motorcycle Helmet. It comprises of motorcycle helmet which defines a cavity in a hard fiber shell. A thermo-electric heat pump is mounted in the cavity, and a light metal radiator is bonded to both shell and pump. One way conductors energize the heat pump from a motorcycle battery source to pump heat from the hard fiber shell to the radiator. A flexible bladder filled with heat transfer liquid is mounted in the hard fiber shell and below the heat pump and in thermal contact with the wearer's head and the heat pump, for conducting head heat to the pump to electrically pump to the radiator for radiation to the atmosphere. However the invention suffers from a major limitation of using a flexible bladder filled with heat transfer fluid in the helmet cavity in contact with the wearer's head. This system is prone to leakages. Further, the wearer may not be comfortable with sense of fluid in contact with his / her head. Since liquid is used for heat transfer that is to distribute/increase heat extraction area, the circulation current that is thermo- symphon effect, this necessities and restricts positioning of this bladder and in turn sink only at the top of the helmet shell. Since only a single thermoelectric cooling element is used, dissipating the cooling and heating effect is difficult which increases the temperature difference across the hot and cold surfaces of the thermoelectric cooling element thereby limiting the performance of the thermoelectric cooling element, which in other words is reducing its cooling effect and increasing its input power. Further limited size of a single heat sink reduces the
performance at low speeds or during standstill conditions due to overheating of sink and thereby the thermoelectric module.
An air conditioned helmet apparatus is disclosed in the patent number US 6954944. It comprises of a thermoelectric heat pump mounted onto a rear surface of the helmet shell for delivering temperature conditioned air to the interior of the helmet shell. A multi-layer structure on the helmet shell interior distributes conditioned air across the scalp and directly onto the face. However this helmet suffers from the shortcoming that fan has to be used and further conduits are to be provided inside the helmet body. This distorts the aerodynamic profile of the helmet. Further, since the substantial volume of air blown by the fan passes on the said thermoelectric cooling element, it results in increased load on the thermoelectric cooling element and moreover it has to take the latent load caused by respiration of the wearer. Since this air enters the cooling element at the ambient temperature and is cooled to inside temperature and finally exhausted at a few degrees higher than inside temperature, substantial amount of the cooling effect provided by the thermoelectric cooling element, 50 to 75%, is lost in the air stream of the cold space back to the ambient. This obviously necessitates increased power supplied to the element to enable adequate cooling.
United States Application 20060101556 discloses Crash Helmet with thermoelectric cooling. It consists of a conditioning system for a helmet having an impact resistant body with an exterior. A first opening is provided in the helmet body located at the back region of the helmet body adjacent a lower edge thereof which acts as an air intake opening. A blower fan communicates with the air intake passage for drawing air into the intake passage and forcing the air from the back region of the helmet in the direction of the front region thereof. A thermoelectric cooling element is located in the helmet interior in communication with the intake passage downstream of the blower fan. The thermoelectric cooling element has a cold side and a hot side. A DC power source is provided for powering the thermoelectric cooling element. An external heat sink is located on the helmet exterior and is connected to the hot side of the thermoelectric cooling element by means of a second opening in the helmet body. Air passing over the thermoelectric cooling element is cooled and air conditions the head receiving region of the helmet. Since this conditioned air enters the thermoelectric cooling element at the ambient temperature and is cooled to inside temperature and finally exhausted at a few degrees higher than inside temperature, the disadvantages of prior art US patent number 6954944 discussed earlier will be present in this system as well. This helmet (like prior art US patent number 6954944) also suffers from the shortcoming that fan has to be used and further conduits are to be provided inside the helmet body. This distorts the aerodynamic profile of the helmet. Further the placement of the heat sink at the top of the helmet near back region is not exposed effectively
with the air that passes over the helmet when the wearer is in motion, this reduces heat dissipation capacity and in turn heat extraction capacity of the element.
United States Patent Application US 2007/0137685 discloses a solar power operated cooling helmet. It comprises of a flat solar ceil module mounted in the top wall of the helmet body, a thermoelectric cooling module, a heat sink bonded to the hot side thereof and a cooling radiator bonded to the cold side and suspending inside the helmet body, and a fan-based cooling air delivery mounted inside the helmet body for delivering cold air to the inside space of the helmet body to comfort the user's head. However the said helmet suffers from the drawback that fan is necessary for internal circulation of air inside the helmet. The power consumed by the fan also adds to the cooling load of the helmet. Since the source of power to the thermoelectric cooling module is based on solar energy incident on the helmet, the power available would be 1/5 th to 1/10 th of that required to satisfy the cooling using the efficient photovoltaic modules available. Hence this system is not technically viable.
Thus study of the prior art reveal several draw backs in the conventional headgears with thermoelectric modules/elements such as: v use of fan / blower mounted in the headgear;
S use of heat transfer fluid in the headgear; S thermoelectric module / chip / element overheating problem when the wearer is not in motion; s provision of additional conduits / passages for the air; s ineffective use of heat sink means on the exterior of the headgear;
S drawing outside air and conditioning the same by passing over the thermoelectric module / chip / element resulting in increased cooling load and in turn voltage / power demand of the thermoelectric element;
S distortion of the aerodynamic profile of the headgear;
V lack of retrofit potential in existing headgears.
Thus necessity has constantly been felt to provide a headgear with a cooling means obviating the use of fan means, air channels / conduits in the headgear and use of heat transfer fluid yet with a retrofit potential.
Summary of the Invention
The main object of the invention is to provide a headgear with a cooling / heating module/s in the form of a solid state thermoelectric heat pump means obviating the use of fan means, air channels / conduits in the headgear and use of heat transfer fluid yet with a retrofit potential.
Yet another object of the invention is to provide a cooling / heating module in the form of a solid state thermoelectric heat pump means employing thermoelectric effect.
Another object of the invention is to obviate passing and cooling air on the solid state thermoelectric heat pump means with an external means.
Another object of the invention is to substantially reduce cold / hot spots inside the headgear.
Yet another object of the invention is to provide a headgear with a substantially reduced protrusion at the exterior thereby reducing the distortion of the aerodynamic profile of the headgear.
Yet another object of the invention is to provide a solid state thermoelectric heat pump means employing thermoelectric effect that is easily adapted on the existing helmet.
Thus in accordance the invention comprises of; headgear with a preferably hard material defining cavities adapted to accommodate / fit cooling / heating module/s in the form of a solid state thermoelectric heat pump comprising a thermoelectric module / chip / element in thermal contact with first thermally conductive means disposed in the said cavity and second thermally conductive means disposed so as to be in contact with outside air;
a power source; optional temperature control means for the said thermoelectric module / chip / element/s.
Description of the Invention
Advantages and features of the present invention will become apparent in the following detailed description of the preferred embodiment of the invention with reference to the drawings.
Figure 1 Schematic of the cooling / heating module in the form of solid state thermoelectric heat pump means (Sheet 1 ) Figure 2 Schematic of the headgear (Sheet 2) Figure 3 Schematic of cross section of the headgear (Sheet 3)
Figure 4 Schematic of the preferred embodiment of the solid state thermoelectric heat pump means (Sheet 4)
Figure 1 depicts schematic of the cooling / heating module 10 in the form of solid state thermoelectric heat pump. The solid state thermoelectric heat pump comprises of a thermoelectric module / chip / element 1, first thermally conductive means 2 that is disposed inside the headgear cavity and the second thermally conductive means 3 that is located on the outside of headgear shell such that it is in contact with ambient air. The said thermoelectric module / chip / element 1 is thermally attached to the said first thermally conductive means 2. The said means 2 is preferably flexible in nature and helps assume the shape of the head of the user / wearer of the headgear and is placed inside the shell.
In one of the embodiments, thermally conductive adhesive is used to attach the second thermally conductive means, thermoelectric module / chip / element and the first thermally conductive means. In one of the embodiments, thermally conductive medium like grease, pads, etc. is used alongwith adhesive or fastening mechanism to attach the said second thermally conductive means, thermoelectric module / chip / element and the said first thermally conductive means.
In one of the embodiments, the first thermally conductive means 2 is of metal and coated / laminated with polymer / rubber / low conductivity based preferably flexible material to reduce cold / hot spots. In one of the embodiments the second thermally conductive means 3 is preferably a ribbed profiled extruded section, with ribs of rectangular, triangular, square or any surface configuration but not limited to it. In yet another embodiment the said second thermally conductive means 3 is in the form of a strip with plurality of pin like elements protruding out from the base of the said strip wherein the pin cross-section could be oval, circular, rhombic, etc., and this cross-section may vary from the base to the tip of the fin. In yet another embodiment plurality of such first thermally conductive means 2 are attached below each other and radially projecting in a same plane to form a star like configuration. In yet another embodiment the said first thermally conductive means 2 is a lamina attached to the said thermoelectric module / chip / element 1.
Another embodiment of the said first thermally conductive means configuration of the solid state thermoelectric heat pump means 49 is depicted in Figure 4. It comprises of thermoelectric module / chip / element 40, the first thermally conductive means 41 in thermal contact with mesh/disc 43 and the second thermally conductive means (not shown). The said first thermally conductive means 41 comprises of central substantially flat portion 42 wherein the said thermoelectric module / chip / element 40 is thermally bonded using thermally conductive material 45. Plurality of the stripe like elements of the first thermally conductive means indicated
as 41 radially protrude outwards wherein the bottom portion 44 of the said first thermally conductive means is adapted to be thermally bonded using thermally conductive material 46 to the mesh/disc 43 distanced from the said flat portion 42 as shown in the figure. Optionally the mesh/disc 43 can be flexible to conform to the contours of the wearer's head.
Figure 2 illustrates the headgear mounted with said cooling / heating module 10 in the form of solid state thermoelectric heat pump means. The head gear comprises of shell 21 of hard material. The shell defines a cavity to accommodate wearer's head. There is provided a sight glass / visor 20. The said shell 21 is adapted to fit the said solid state thermoelectric heat pump means wherein the said second thermally conductive means 3 of the solid state thermoelectric heat pump means protrudes preferably less than 5 mm but not limited to it and is exposed to the atmosphere. Second thermally conductive means 3 of multiple solid state thermoelectric heat pump means mounted in the headgear are shown in the Figure 2 as a representation, it may be noted that there can be one or plurality of solid state thermoelectric heat pump means disposed in the headgear. The thermoelectric module / chip / element 1 and the first thermally conductive means 2 is disposed inside the said shell which is not seen in Figure 2. It may be noted that one or plurality of solid state thermoelectric heat pump means 10 can be disposed at suitable locations in the said shell 21. The solid state thermoelectric heat pump means 10 can be disposed at a location or various locations in the headgear.
Figure 3 depicts exaggerated view (not to scale) indicating the configuration of the said solid state thermoelectric heat pump means 10 with the said shell 21 of the headgear. The section of the headgear is shown in the figure. The headgear shell 21 defines a cavity 30 at the interior of the headgear (to accommodate wearer's head). Part of the said second thermally conductive means 3 protrudes (preferably less than 5 mm) from the exterior of the shell; the said thermoelectric module / chip / element 1 and the said first thermally conductive means 2 are disposed in the interior of the headgear as shown in Figure 3. It may be noted that there can be plurality of first thermally conductive means 2 attached to the said thermoelectric module/chip/ element 1 disposed inside the headgear. The said solid state thermoelectric heat pump means 10 is provided with a provision for power source connection.
In one of the embodiments there is provided a temperature control system comprising one or plurality of temperature sensing, measuring and optionally indicating means disposed inside the said headgear in connection with a voltage regulating means and the said power source configured with the said solid state thermoelectric heat pump means 10 to facilitate automatic temperature control to desired / preset temperature.
In yet another embodiment the said second thermally conductive means 3 is provided with a selective coating on the profiled part that protrudes from the said headgear shell 21 which will reduce the absorption of solar radiation while increasing the emission in the thermal spectrum. In yet another variant, the said part of the said second thermally conductive means 3 is anodized for better corrosion resistance and to improve aesthetic appeal.
In yet another embodiment the said first thermally conductive means 2 and mesh/disc 43 is laminated / coated with polymer / rubber / low conductivity based preferably flexible material 47 to reduce cold / hot spots.
In yet another embodiment the said first thermally conductive means 2 is in the form of wired matrix structure laminated / coated with rubber / polymer / low conductivity based preferably flexible material 47 to reduce cold / hot spots.
In one of the embodiments the said second thermally conductive means 3 is provided with a temperature sensing means in connection with the said power source to control voltage input thereby temperature of the said thermoelectric module / chip /element 1 when appropriate heat dissipation from the said second thermally conductive means 3 is ceased in particular when the vehicle moves substantially slowly or is in a standstill position to avoid overheating of the thermoelectric module / chip / element.
In yet another embodiment the said power source is in the form of a thermoelectric generator wherein the thermoelectric generator module / chip / element is supplied with heat from the exhaust gases of the vehicle to generate electric power.
In another embodiment the said power source is solar energy.
In another embodiment the said power source is the motorcycle/vehicle battery.
In yet another embodiment the solid state thermoelectric heat pump means 10 in the headgear is adapted to removably receive quick release retractable wire mechanism so as to operably connect to the power source so that the safety of the user is not compromised in the case of the slightest jerk/impact on the headgear during an accident or otherwise. The quick release mechanism will avoid the jerk on the connecting wire to reach the headgear and the retractable mechanism will avoid the wire from entangling with the user or vehicle during any impact or accident.
Thus it is evident that the synergistic combination of a single or preferably multiplicity of cooling / heating module/s in the form of solid state thermoelectric heat pump means 10 comprising a thermoelectric module / chip / element, flexible first thermally conductive means laminated / coated with polymer / rubber base material and second thermally conductive means disposed in the headgear results in obviating the use of fan / blower, need to pass air on the thermoelectric module / chip / element and substantially reduced cold / hot spots resulting in enhanced and improved cooling / heating effect delivery to the wearer yet facilitating retrofitting of the said solid state thermoelectric heat pump means 10 in the existing headgear without the use of separate air conduits, channels thus making the system cost effective while reducing required power input. Also compared with other thermoelectric helmets where ambient air is cooled and supplied inside the headgear, the cooling load required in the present helmet will be 50 to 75% lower because of elimination of loss of cooling effect due to cold air leaving the helmet at a temperature substantially lower than the ambient air being cooled. For example in other thermoelectric helmets if the ambient air is at 45C and the thermoelectric module cools this air down to 25C and supplies it inside the headgear which is to be maintained at 27C to 3OC, the air will leave the helmet at 3OC. In this example the cooling effect delivered by the thermoelectric module will be to pull the air from 45C to 25C, a temperature difference (delta T) of 2OC. Since 25C air picks up heat inside the helmet, delivers the cooling as it heats up to 3OC, a temperature difference (delta T) of 5C, the useful cooling effect is only 25%. Hence in such a situation cooling effect required to be delivered by the thermoelectric module will be four times the actual cooling load.