This invention relates generally to helmets, more particularly concerns protective helmets which can be cooled down by using Peltier thermoelectric effect in conjunction with a ventilation structure.

Background of this invention

The major objective of protective helmets is to protect the wearer's head which can be seriously bumped when playing sports activities, and more particularly for two- wheeler riders, such as motorcycles, bicycles. To this end, the helmet usually consist of at least two layers which have been entirely overlapped on each other, that is, the outer layer being composed of hard resin, and the inner padding layer. Moreover, the helmet usually have additional common portions such as helmets' brim in order to protect the wearer from the sun and helmet strap in order to keep helmet stable on the user's head.

The inner padding layer is made from materials which have shock-absorbing ability to absorb shocks in case of a trouble, most commonly expanded polystyrene (EPS). Such materials typically have insulation properties. On the other hand, although there is a small space between the wearer's head skin and the inner surface of the insulation layer, this space is often not big enough to keep the head skin ventilated, that is, the heat from the wearer's head cannot escape out, the sweat from the scalp makes the humidity in this small space increased, thereby the users often feel very uncomfortable in case of the long use, especially on sunny days or warm, humid weather, or when they got stuck in congestion or traffic jam. It may cause danger when temperature inside the helmet becomes too high because the motobiker wearing the helmet might decrease his focus and attention when riding.

Therefore, the wearers do not give preference to helmets which have the chin protective portion, instead, they give preference to half helmets, more preference is given to the helmets having a wide cut near the ear because the wind from the outside shall at least be able to cool down the inside of the edge of the helmet.

Many people choose large helmets, and/or the strap have not been buckled properly in order to make their head feel cooler, regardless of the unsafety which might be occurred whenever they got in trouble.

There are a lot of improvements to enhance the air circulation between the padding layer and wearer's head skin.

The benefits of solutions such as adding a thin net layer which closely embraces the head of the wearer, or adding a thin padding layer of fabric right beneath the padding layer, etc., are not high because the space between the head skin and the inner surface of the padding layer has been insignificantly increased.

At the same time, Peltier panel has become widely used in machines, refrigeration, cooling or radiating facilities, such as fridges, refrigerators, hot and cold water dispenser, wine cooling fridges, beer refrigerators, fish tank coolers, radiators for central processor units (CPU) of a computer, medical devices, cosmetic tools, etc ... Peltier panel has also been used for heating purposes (heating).

Peltier panel, also called Peltier chip or Peltier module, is a semiconductor structure which in nature acts as a heat pump, including two sides: the hot side and the cool side and is capable of heat transferring from the cool side to the hot side, that is to cool down the hot side when there is a direct current running through.

Currently there have been certain solutions that suggest using Peltier panel to cool down the protective helmet.

Japanese Patent Publication No. JPH 10212616 (Sasaki Kazuo and Hirano Masami) has proposed the protective helmet which has been provided with air conditioning system to prevent the helmet wearer from the discomfort and the distraction. The air conditioning system includes Peltier module operated by means of the electrical current derived from the solar panels and/or rechargeable batteries to cool down the inside of the helmet. In addition, there is also a controller which serves to disconnect the electrical current supplied to Peltier module in order to set appropriate temperature inside the helmet. This document indicates that when there is a suitable electrical current, Peltier module, mounted on the top of the shock absorbing layer of the protective helmet, can cool down the inside of the helmet.

However, since the shock absorbing layer of the protective helmet usually is very close to the head skin, there is only a limited space near the top of the head, it can be observed that the cool air from Peltier module can cool down only a limited space around it, that is the limited space near the top of the wearer head. Therefore, in order to cool down the whole head skin beneath the protective helmet, there is a need to force the air from outside to the inside of the helmet and from the inside of the helmet outwardly.

Disadvantages of the technical solution described in Japanese Patent Publication No. JPH 10212616 have been proved in the document "Cooling of Motorcyclist Helmet with Thermoelectric Module" of M. Hrairi, A.F. Abdullah and M.I. Ahmed (Middle-East Journal of Scientific Research 13 (Mathematical Applications in Engineering): 103-108, 2013) which describes the development of the colling system for the protective helmet wherein the thermoelectric modules have been used. When a voltage is applied to the thermoelectric modules, these modules creat the temperature difference between its two sides, that is causing the Peltier effect. Results of the prototype manufacturing and testing show that the temperature inside the protective helmet decreases from 25.5°C to 19.3°C within 6 minutes. However, in the examples presented, this document indicated that a fan is needed for blowing the air, two aluminium tubes are required for directly forcing the air going in and out. Main disadvantage of this solution has also been described, such as, in particular, the air ventilation tubes are not sufficient enough for circulation of the cool air from Peltier module. On the other hand, this system can be effective only when motorcycles have reached high speed, such as 70 km/h. Therefore, in case of traffic jam, this solution is not as effective as desired. The solutions suggested in this document such as to improve the cooling effect by means of compentent thermoelectric modules or using less noisy fans could not solve the problem of the cooling effects. The US Patent No. US 7,296,304 (Goldsborough) describes the helmet having the thermoelectric cooling system which includes a DC power source which supplies power to the thermoelectric coolers mounted inside the helmet, a fan mounted outside in the back of the helmet in order to guide the air in/out through the air guide channels and through the heat exchange regions thanks to thermoelectric cooler. The air guide channels arranged beneath the hard shell layer, include the branch lines extending through the shock absorbing padding layer and the main guiding path arranged at the top of the helmet on the outer surface of the shock absorbing padding layer, that is between the shock absorbing padding layer and the outer shell layer. With the air guide channels being limited in term of the number and their locations, one drawback of this solution is that it requires to force air through the thermoelectric coolers, that is there is a demand for a fan, power supply, etc.

Therefore, there is a demand for a protective helmet which ensures the safety function and at the same time is capable of the head skin cooling without fans, even when the motorcycle moves at low speed or stands still.

The invention has proposed solutions to satisfy the needs mentioned above.

Summary of the invention

One objective of the invention is to provide the protective helmet which still has the ventilation property and smoothness while ensures the safety functions for the wearers.

The above objective shall be obtained by proposing a helmet having a thermoelectric cooling system, including: a hard outer shell layer and a shock absorbing padding layer, inside the hard outer shell layer there is at least one through-hole at the top area; a plurality of the air guide channels arranged in the inner side of the shock absorbing padding layer and communicating the through-hole outwardly at the lower edge of the shock absorbing padding layer; a radiator attached to the outer side of the hard outer shell layer; at least one Peltier module arranged inside the through-hole so as the cool side contacts with the intersection point of the air guide channels and the hot side adjacent to the radiator; solar panels are connected to the power supply for supplying power to Peltier module.

Brief description of drawings

For more complete understanding of nature, characteristics, advantages of the invention, reference is now made to the following description taken in connection with the accompanying drawings in which:

Figure 1 is a partially section view along the symmetrical axis of the helmet having the thermoelectric cooling system in accordance with one embodiment of the invention;

Figure 2 is an enlarged view of part I of Figure 1 ;

Figure 3 is a plan view of the helmet having the thermoelectric cooling system in accordance with one embodiment of the invention;

Figure 4 is a bottom view of the shock absorbing padding layer of the helmet having the thermoelectric cooling system in accordance with one embodiment of the invention;

Figure 5 is a section view of the shock absorbing padding layer of the helmet having the thermoelectric cooling system in accordance with one embodiment of the invention; and

Figure 6 is a bottom view of the shock absorbing padding layer of the helmet having the thermoelectric cooling system in accordance with another embodiment of the invention.

Detailed description of preferred embodiments of the invention

As illustrated in drawings from Figure 1 to Figure 4, a helmet having the a thermoelectric cooling system in accordance with one embodiment of the invention includes: a hard outer shell layer 10,

a shock absorbing padding layer 20 snugly mounted inside the hard outer shell layer 10; and

known conventional parts of protective helmet, in particular, the protective helmet used for motobikers, or the protective helmet used for workers, such as a helmet brim 50, a helmet strap 60, a windshield, the inner lining made of the mesh or cheesecloth, etc..

The characterizing feature of the helmet having the thermoelectric cooling system of the invention is it has at least one through-hole 23 (see Figure 4) extending through both the hard outer shell layer 10 as well as the shock absorbing padding layer 20; and a plurality of the air guide channels arranged in the inner side of the shock absorbing padding layer 20 and communicating the through-hole 23 outwardly at the lower edge of the shock absorbing padding layer 20;

a radiator 31 attached to the outer side of hard outer shell layer 10 and tighly sealing the through-hole 23;

at least one Peltier module 30 arranged inside the through-hole 23 so as the cool side 301 contacts with the intersection point of the air guide channels and a hot side 302 is adjacent to the radiator 31 ;

a solar panel 40 connected to supply power to Peltier module 30.

In Figure 1 , a half of the helmet of the invention when being sectioned along the symmetrical axis was removed in order to show the air guide channels in the inner side of the shock absorbing padding layer 20.

Although Figure 4 illustrates the shock absorbing padding layer 20, it should be understood that the through-hole 23 is formed in the hard shell layer 10 and the shock absorbing padding layer 20 at the same position and having the shape and size as substantially the same.

In one embodiment in practice, the helmet of the invention is a half helmet type of medium size, the through-hole 23 has a square shape with dimensions of about 30 x 30 (mm), the Peltier module 30 coding as TEC 1- 12706, is square with dimensions of 30 x 30 x 3.6 (mm), maximum capacity of 61 ,6 W, operating voltage of 12 V, the radiator 31 is an aluminum plate of 4 x 16 (mm) arranged longitudinally on the helmet, and having 6 solar panels, each panel has a dimension of 50 x 120 (mm), total capacity of 6W manufactured by V Solar (Viet Nam).

As illustarted in Figure 2, the Peltier module 30 is tightly attached to the radiator 3 1 , in particular the hot side 302 is in direct contact with the radiator 3 1 while the cool side 301 faces the unoccupied space which is the rest of the through-hole 23 after the through-hole 23 had been sealed at one end by the radiator 31.

Because the radiator 3 1 tighly seals the through-hole 23 and the radiator 31 has a certain hardness, the hardness of the helmet of the invention is unaffected by the presence of the through-hole 23.

As illustrated in Figure 3, the solar panels 40 can be arranged to cover the radiation aluminium panel 31 or on both sides of the radiation aluminium panel 3 1.

Preferably that there is at least one solar panel 40 covering the radiator so sunlight does not increase the temperature of the radiator 31 to ensure the effectiveness of operation of Peltier module 30.

In one prefered embodiment of the invention, the air guide channels are channels formed in the inner side of the shock absorbing padding layer 20 as being illustarted in Figure 5. In this embodiment, the channels have an arched cross-section. However, the channels can have any cross section shape, such as semicircle, square, rectangular, or half-ellipse. An advantage of the channels having arched, semicircle or half-ellipse cross- section is that they have little effect on the force-resistance capacity and ability to absorb the shock of shock absorbing padding layer 20.

It is possible to form the air guide channels having a desired shape and layout by means of known conventional methods, such as making projecting ribs on the inner side of the mould of the shock absorbing padding layer, or shaping the channels after moulding the shock absorbing padding layer. In practical embodiments, the diameter of semicircle or the width of the arch have size ranging from 2 to 5 mm and the height of the arch is in the range from 2 to 5 mm.

The channel reduces the contact area and increase the space between the head skin and the inner side of the helmet, to help the air easily circulated from outside to the space beneath Peltier module and vice versa. This design not only ensures the effectiveness of Peltier module but also is capable of conveying the hot and humid air inside the helmet outwardly together with the sweat (if any) and transfers the cool air from the Peltier module, that is from the top of the head downwardly to cool down the head skin inside the helmet.

It is possible to calculate the size of the channels and adjust the thickness of the shock absorbing padding layer, that is the thickness from the bottom of the channel to the, outer side of the shock absorbing padding layer, to ensure the standard size of the helmet in order to ensure the safety of the users.

For the helmet of the invention which has the thermoelectric cooling system, there are different arrangements of layout of the the air guide channels.

As illustarted in Figure 1 and Figure 4, the air guide channels can include multiple circular arcs in the meridian direction 21 and in the latitudinal direction 22 of the helmet. The air guide channels in the meridian direction 21 which perform the function of guiding the air in/out in contact with the cool side 301 (see Figure 2), the air guide channels in the latitudinal direction 22 act as the air dispenser to scatter the air throughout the inner side of the shock absorbing padding layer 20, that is throughout the inner side of the helmet.

In another embodiment, the channels include multiple circular arcs in the meridian direction of the helmet. It can be observed from practice that this embodiment is also capable of cooling the inside of the helmet.

In the drawings, the channels have a constant cross-section. However, it is also possible to design and manufacture of different sizes. For example, the channels can be in the positions where the inner side of the shock absorbing padding layer is adjacent to the head skin and can be shallower at the positions where the inner side of the shock absorbing padding layer is far from the head skin, such as the region back of the neck.

In another preferred embodiment, as illustrated in Figure 6, the channels include multiple circular arcs 24 located in parallel planes and multiple circular arc 25 located in the inclined planes inclining certain angles relative to the longitudinal axis of the helmet. Figure 6 illustrates the helmet having the thermoelectric cooling system with two Peltier modules mounted on two through-holes 23a, 23b, respectively. In this specification, a longitudinal axis is the axis of symmetry in the direction from front to the back of the helmet.

Depending on the capacity of Peltier module, the size of the helmet (such as large- size, medium-size, small-size), or type of the helmet (such as the type having a chin protective part, the type having a front wind shield, the half helmet type, etc.), it is possible to canculate and arrange the required number of Peltier modules.

In another embodiment, instead of the air guide channels there is a ventilation padding layer as described in the patent application No. 1 -2015-04326 of the same inventor with all characteristics of the ventilation padding layer incorporated herein as reference.

According to that, the helmet having the thermoelectric cooling system in accordance with another embodiment of the invention has a ventilation padding layer arranged fittedly beneath a shock absorbing padding layer 20, wherein the ventilation padding layer includes:

a frame shaped to fit with the wearer's head and having the through-holes arranged in longitudinal and horizontal rows, crossed over each other on its surface; and

the wavy bars affixed to the top surface of the ventilation padding layer at the position between the crossed horizontal and vertical rows of the frame.

Functionally and structurally, the ventilation padding layer creates the gap between the inner side of the shock absorbing padding layer 20 and the head skin of the wearer, that is forming a passage having a role as the air guide channels from the through-hole 23, that is from the Peltier module 30 outwardly at the lower edge of shock absorbing padding layer 20, therefore this embodiment also has all the characteristics of the invention as presented above.

Experimental results show that, thanks to the air guide channels formed in the inner side of the shock absorbing padding layer 20 or the ventilation padding layer, the helmet having the thermoelectric cooling system of the invention is capable of cooling the inside of the helmet without fan to enforce air to circulate from inside the helmet outwardly and vice versa. In addition, the circulating air flow exists even when the motorcycle moves at low speed or stands still. On other words, the air guide channels or the ventilation padding layer in accordance with embodiments of the invention is sufficient to create the asymmetrical position therefore the path from the gap to the output/input at the edge of the helmet has different lengths and force resistance and thereby ensuring the convection air flow flowing in/out of the inner side of the helmet of the invention.

The test results with the helmet having the parts as mentioned in the above practical embodiment has indicated that, when the outdoor temperature is 40.5 °C, the vehicle stands still, the weather is sunny, the voltage and intensity of the power current measured as 3 V and 0.09 A, respectively, the temperature measured inside the helmet having the thermoelectric cooling system of the invention is 26.3 °C, and the helmet wearer feels cool and comfortable.

In another embodiment, the helmet having the thermoelectric cooling system it further comprises a switch (not shown in the drawings) to switch off the power current from the solar panels 40 to Peltier module. This embodiment allows the user stop using the cooling function in cold weather.

In another embodiment, the helmet having the thermoelectric cooling system it further comprises a temperature sensor and controller to switch on/off the power current from the solar panels 40 to Peltier module depending on the temperature inside the helmet. Although it is rather complicated and probably costly, this embodiment allows user to optionally adjust the temperature inside the helmet, to avoid overcooling the head skin when it's sunny but temperature is low.

The average person skilled in the technical field of the invention can easily design and layout of the circuit components, such as the switch, the sensor, the display, the setting temperature receiver from the user, the switch controller, etc..

Utility of the invention

It can be observed that the ventilation helmet of the invention also includes the hard shell layer and the shock absorbing padding layer which are known and conventional. Therefore, it can utilize the available production lines to produce the ventilation helmet of the invention. Due to the size of the air guide channels occupies a small percentage compared to the thickness of the shock absorbing padding layer, the helmet of the invention is able to meet the strict standards applied to the hard shell layer and the shock absorbing padding layer.

The protective helmet having the cooling system of the invention is capable of creating a sense of cool, eliminating distraction when the weather is sunny and/or in case of traffic congestion, thereby it may encourage the wearer using the protective helmet properly, to ensure safety in taking traffic.

Other embodiments

It is also noted herein that while the above describes example embodiments of the invention, these descriptions should not be viewed in a limiting sense. Rather, a person skilled in the art shall understand that there are variations and modifications which may be made to the change of the helmet shape, the position and number of the Peltier modules, the shape and the arrangement of the air guide channels, etc., without departing from the scope of the present invention as defined in the appended claims.