Patent Publication Number: US-2013228562-A1

Title: Heater sewn on clothes

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a heater, especially to a heater sewn on clothes having a stable connection and higher heating performance. 
     2. Description of Related Art 
     In order to keep warm in a cold weather, people wear thick and heavy clothes and feel uncomfortable. The clothes also cause trouble in storage. Thus various devices including disposable heat pads, pocket warmers, or heating bags are provided for getting additional heat. However, these devices can only keep local areas warm and the heating temperature can&#39;t be adjusted. Moreover, they stay hot for a short period and the heat preservation is poor. 
     Refer to U.S. Pat. No. 7,105,782, an electrothermal article is revealed. The electrothermal article includes a plurality of heating elements disposed in an inner space between two fabric sheets. An adhesive layer is for bonding intermediate portions of the heating elements to the fabric sheets. Such design is not only time-consuming and labor-intensive during manufacturing processes but also leading to increasing cost. Moreover, the adhesive layer made from an adhesive material having a low melting point is easy to be melted while the heating elements working. Thus the adhesion is not stable and not strong enough. Furthermore, the heating elements are not fixed or separated by any other parts besides the adhesive layer. Once the heating elements fall off from the fabric sheet due to melted adhesive layer or washing, the heating elements are not distributed over the fabric sheets. Thus the heat supply is uneven and the efficiency is reduced. 
     Refer to U.S. Pat. No. 7,135,036, a heating pad is disclosed. The heating pad includes an envelope containing a metal plate and a resistance heating element attached to the metal plate. Once an opening of the envelope is open, water may infiltrate during washing processes. Thus the metal plate with the resistance heating element gets damaged. 
     Refer to U.S. Pat. No. 6,573,48, an electrical heating wire assembly is disclosed. The electrical heating wire assembly includes a heating wire with electrical heating filaments, a conductive wire, and a connector interconnecting the heating wire and a conductive wire. The connector is composed of a conductive body having a block portion and a pin portion projecting from the block portion into the heating wire to contact the heating filaments. An insulator sleeve is sleeved on the conductive body, ends of the heating wire and the conductive wire. Only a part of the heating filaments inside are in contact with the pin portion while the heating filaments outside are not connecting with the pin terminal. Thus a high temperature hot spot occurs around this area due to high resistance while current flowing from the conductive wire to the electrical heating filaments. The current is not conducted well to flow through the whole heating filament. Therefore the temperature of the heating filament is lower than the connection area between the contact area between the heating filaments and the pin portion and the heating is not ideal. 
     Thus there is room for improvement and a need to provide a novel heater on clothes that overcomes the above shortcomings. 
     SUMMARY OF THE INVENTION 
     Therefore it is a primary object of the present invention to provide a heater sewn on clothes, having a stable connection and with better heating efficiency. 
     In order to achieve the above object, a clothes heater according to the present invention includes a cover layer and a heating unit. 
     The cover layer consists of an inner layer, an outer layer and an intermediate layer formed between the inner layer and the outer layer. One side of the inner layer and one side of the outer layer that form the intermediate layer are respectively disposed with a layer of waterproof membrane having a high melting point. The thickness of the inner layer is smaller than the thickness of the outer layer. 
     The heating unit is placed at the intermediate layer and is composed of a high resistance filament and conductive wires connected to the high resistance thread. One end of the conductive wire connected to the high resistance filament is divided into at least two strands of electric filaments, respectively wound around the high resistance filament. The other end of each conductive wire is extended out from the cover layer to be electrically connected with a controller and a power supply unit respectively. 
     The waterproof membrane with the high melting point is belt by high temperature and high pressure treatment. Thus the heating unit is connected to the waterproof membrane of the cover layer and water resistance is achieved. Moreover, the conductive wires of the heating unit are connected to the high resistance filament by strands of electric filaments so as to reduce resistance between the high resistance filament and the conductive wire. Thus thermal efficiency of the heating unit is increased. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein: 
         FIG. 1  is a perspective view of an embodiment according to the present invention; 
         FIG. 2  is an explosive view of an embodiment according to the present invention; 
         FIG. 3  is a partial enlarged view of a heating unit of an embodiment according to the present invention; 
         FIG. 4  is a perspective assembly view of an embodiment according to the present invention; 
         FIG. 5  is a cross sectional view of an embodiment according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Refer to  FIG. 1  and  FIG. 2 , a heater sewn on clothes according to the present invention includes a cover layer  1  and a heating unit  2 . 
     The cover layer  1  consists of an inner layer  11 , an outer layer  12  and an intermediate layer  13  formed between the inner layer  11  and the outer layer  12 . One surface of the inner layer  11  and one surface of the outer layer  12  forming the intermediate layer  13  are respectively disposed with a waterproof membrane  14  having a high melting point. The waterproof membrane  14  is made of polyurethane. The thickness of the inner layer  11  is smaller than the thickness of the outer layer  12 . 
     As shown in  FIG. 2  and  FIG. 3 , the heating unit  2  is disposed in the intermediate layer  13  of the cover layer  1 . The heating unit  2  is composed of a high resistance filament  21 , conductive wires  22  connected to the high resistance filament  21  and a heat shrink sleeves  23 . The high resistance filament  21  is made from metal or carbon fiber. One end of the conductive wire  22  connected to the high resistance filament  21  includes at least two strands of electric filaments  221  wound around the high resistance filament  21 . Thus contact area between the electric filaments  221  of the conductive wire  22  and the high resistance filament  21  is increased. The heat shrink sleeve  23  made from soft and elastic material is wrapped around a contact point where the conductive wire  22  and the high resistance filament  21  are connected to each other, covering the contact point. Moreover, the other end of each conductive wire  22  is extended out from the cover layer  1  to be electrically connected with a controller and a power supply unit respectively. 
     While being assembled, refer to  FIG. 2  and  FIG. 4 , the high resistance filament  21  already connected with conductive wires  22  in advance is bent to form a plurality of portions arranged neatly on the waterproof membrane  14  of the inner layer  11  of the cover layer  1 . Then one side of the outer layer  12  with the waterproof membrane  14  is covered over the high resistance filament  21 . Thus the outer layer  12  is attached to the inner layer  11  and the high resistance filament  21  is mounted in the intermediate layer  13  formed between the outer layer  12  and the inner layer  11 . Next high temperature and high pressure are applied to outer sides of the inner layer  11  and the outer layer  12  of the cover layer  1  so as to make the waterproof membranes  14  with the high melting point on the inner side of the inner layer  11  and of the outer layer  12  respectively melt, as shown in  FIG. 5 . Thus the inner layer  11  and the outer layer  12  of the cover layer  1  are connected to each other by the melt waterproof membrane  14 . At the same time, the high resistance filament  21  in the intermediate layer  13  between the outer layer  12  and the inner layer  11  is also connected well with the waterproof membrane  14  being melted and is tightly fixed in the intermediate layer  13  of the cover layer  1  after the waterproof membrane  14  being cooled. Thereby water will not infiltrate into the contact point between the high resistance filament  21  and the conductive wire  22  due to the waterproof membrane  14 . While the clothes being washed and scrubbed, the contact point between the high resistance filament  21  and the conductive wire  22  will not get damaged easily due to the heat shrink sleeve  23  wrapped the contact point between the conductive wire  22  and the high resistance filament  21 . Later each of a plurality of dividing lines  15  is sewn between two adjacent parallel portions of the high resistance filament  21  on the cover layer  1  so as to separate the portions of the high resistance filament  21  from each other and avoid contact between the adjacent parallel portions of the high resistance filament  21  that reduces heating effect. The periphery of the inner layer  11  is sewn and connected to the periphery of the outer layer  12 . The assembly of the cover layer  1  with the heating unit  2  is completed. 
     The assembled cover layer  1  and the heating unit  2  are sewn and fixed onto clothes, gloves, hats, shoes, etc. When people really feel cold in winder or bad weather and need to keep warm, they put on clothes with the present invention. Then the power supply unit is turned on by the controller and electric current is passed through the conductive wire  22  to flow through the high resistance filament  21 . Thus the high resistance filament  21  gets heated up and a large amount of heat is produced. The heat is transferred to users&#39; bodies through the cover layer  1 . The heat from the high resistance filament  21  is transferred easier through the inner layer  11  as the sickness of the inner layer  11  of the cover layer  1  is smaller than the outer layer  12 . Thus most of heat is delivered to warm up users&#39; bodies. Moreover, the thicker outer layer  2  on the outer side is used for thermal insulation. Thereby energy saving is achieved. 
     Furthermore, the contact area between the conductive wire  22  and the high resistance filament  21  is significantly increased due to the strands of electric filaments  221  wound around the high resistance filament  21 . Thus resistance at the contact point between the high resistance filament  21  and the conductive wire  22  is reduced while the current flowing through. Therefore hot spot heating will not occur and the current flows to the high resistance filament  21  effectively. The thermal efficiency of the high resistance filament  21  is improved. 
     In summary, the present invention has following advantages: 
     1. One side of the inner layer and one side of the outer layer of the cover layer are respectively disposed with a layer of the waterproof membrane having the high melting point. The sides of the inner layer and the outer layer with the waterproof membrane are placed facing each other and connected to form the intermediate layer for receiving the heating unit. While being assembled, the high resistance filament is bent and mounted in the intermediate layer. Then the inner and outer layers are treated by high temperature and high pressure for melting and connecting the waterproof membranes of the inner and the outer layers. The cover layer and the heating unit are assembled with each other quickly.
 
2. Due to high melting point, the waterproof membranes on the surfaces of the intermediate layer formed between the inner and the outer surfaces of the cover layer will not melt when the high resistance filament gets heated up. Thus the stable assembly of the cover layer with the high resistance filament and waterproof effect of the high resistance filament are ensured.
 
3. One end of the conductive wire of the heating unit is divided into a plurality of strands wound around and connected to the high resistance filament. Thus the contact area between the high resistance filament and the electric filament of the conductive wire is increased dramatically to reduce resistance on the contact point between the high resistance filament and the conductive wire. Thus the current flows to the high resistance filament smoothly and thermal efficiency of the heating unit is improved.
 
4. Due to smaller thickness of the inner layer than the outer layer of the cover layer, heat from the heating unit in the intermediate layer between the inner and outer layers is transferred through the thinner inner layer quickly. Thus most of the heat is delivered to and absorbed by the users. Safety in operation is assured.
 
5. Each parallel portion of the high resistance filament is separated exactly due to the dividing lines sewn between two adjacent parallel portions of the high resistance filament on the cover layer. Thereby the adjacent parallel portions of the high resistance filament will not contact each other while in use or being washed.
 
6. During washing and scrubbing, the contact point will not break or damage easily under influence of external forces because that the contact point between the high resistance filament and the conductive wire is protected by the heat shrink sleeve.
 
     Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, and representative devices shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalent.