Abstract:
The present invention provides a thermos bag, which includes a container bag and an built-in thermos device. The thermos device includes a frame, a conductive plate, a printed electrothermal plate, an automatic temperature control device, an insulating lining and a bottom plate as a cover unit. After placing it inside the container bag, with the fixation ring sleeve, foot mount and bolts, it is positioned between the thermos device and container bag. The thermos bag made of this structure provide provides the traveler with a thermos bag that is easy to assemble, easy to carry, energy saving and easy to take off for cleaning.

Description:
RELATED U.S. APPLICATIONS 
   Not applicable. 
   STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
   Not applicable. 
   REFERENCE TO MICROFICHE APPENDIX 
   Not applicable. 
   FIELD OF THE INVENTION 
   The present invention relates generally to a thermos bag for travel use, and more particularly to a hidden thermos device, which includes a frame, a fixation ring sleeve, a conductive plate, a printed electrothermal plate, an automatic temperature control device, insulating lining and bottom plate. 
   BACKGROUND OF THE INVENTION 
   When people travel, they usually carry some food with them in case of hunger, and among the selections of food they carry, some of them may need to be heated or be kept warm to maintain the taste, however, in terms of traveling in the car, people obviously are not going to carry an oven that is huge and heavy, and not to mentioned it uses lots of electricity. 
   For this reason, some businesses have developed some thermos products that are easy to carry to meet the demand, except, the typical spatial structure of the current thermos bag usually places the part with thermos device in it by a cover base, then assembles the cover base on the outside of the bottom of the bag, and in so doing, besides causing the difficulty between the cover base and bag and the problem of increasing the components, it affects the look of the bag because of the design of the cover base being exposed on the outside; therefore, there is still room for improvement. 
   Thus, to overcome the aforementioned problems of the prior art, it would be an advancement if the art to provide an improved structure that can significantly improve the efficacy. 
   To this end, the inventor has provided the present invention of practicability after deliberate design and evaluation based on years of experience in the production, development and design of related products. 
   BRIEF SUMMARY OF THE INVENTION 
   1. The thermos bag disclosed in the present invention primarily uses the printed electrothermal plate  50  to achieve the thermos function, because of the printed electrothermal plate is a structure of MYLAR, compare to the conventional electrothermal plate, it has the advantages such as energy saving, temperature rises fast, small and light. Therefore, the present invention has combined it into the structure of a travel bag to provide traveler a simple and convenient way for thermos heating, and make it a best friend while people travel. 
   2. The present invention uses the structure design of the internal heating device to place the main components of the heating device inside the container bag  10 , and in so doing, it can make the positioning between the thermal device and the container bag easier to achieve (because it can use the base wall of the container bag directly as supporting surface), and reduce the numbers of component to the minimum, moreover, it can make the appearance of the container bag prettier. 
   3. The structure of the thermos device of the present invention comprises of a frame  20 , a conductive plate  40 , the printed electrothermal plate  50 , an automatic temperature control device  60 , an insulating lining  70  and the bottom plate  80 , which makes the thermos device a single unit. Place it inside the container bag when assembling it, then with the fixation ring sleeve  30 , the foot mount  90  and the bolts  92  to achieve the positioning between the thermos device and the container bag, which makes it more convenient and highly effective, and the user can easily take out the thermos device inside to clean the container bag. 
   4. The thermal device of the present invention uses the design of the frame  20 , the insulating lining  70  and the bottom plate  80 , and the effect of the printed electrothermal plate  50  and the conductive plate  40  that creates heat and increases the temperature when being operated to insulate the base wall  14  of the container bag  10 , and in so doing, it creases the insulation effect when the temperature rises and can still be safe. 
   5. The present invention takes the through holes  91  of the foot mount  90  mentioned above and connect them to the protruding rods  83  on the bottom plate  80  through bolts  92  to achieve the positioning effect, and by assembling the foot mount  90  to make the positioning among the foot mount  90 , the bottom plate and the container bag  10 , which tightly secure the entire unit. 
   Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       FIG. 1  shows a perspective external view of the thermos bag of the present invention. 
       FIG. 2  shows a perspective view of the thermos bag of the present invention. 
       FIG. 3  shows the first exploded perspective view of the thermos bag. 
       FIG. 4  shows the second exploded perspective view of the thermos bag. 
       FIG. 5  shows a local sectional view of the partial thermos bag of the present invention. 
       FIG. 6  shows another local sectional view of the partial thermos bag of the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The features and the advantages of the present invention will be more readily understood upon a thoughtful deliberation of the following detailed description of a preferred embodiment of the present invention with reference to the accompanying drawings. 
   As shown in  FIGS. 1–6 , there is a preferred embodiment of the thermos bag. 
   The invention includes a container bag  10 , which may be shaped differently; it is a square box in this embodiment, and it forms a containing space  11  inside, and the container bag has an opening  12 , and the opening may be opened by the design of zipper, so the food or object may be placed inside the containing space, please see  FIG. 4  for the opening condition; a handle strap  13  (such as handle or strap) may be placed on the container bag  10  in convenience of carrying the entire container with hand or on the back, and among them, the walls of the container bag  10  may be better with heat resistant material, and to respond to the heat resistance this invention must have to have “thermos function”, and the base wall  14  of the container bag  10  must have several through holes  140  that are spaced apart, and one side wall  15  of the container bag  10  must have through opening  150 . 
   The invention includes a built-in thermos device, which is to be placed at the bottom of the containing space of the container bag  10  mentioned above. 
   There is a frame  20  with a convergent opening  21  on the top, and divergent opening  22  that have several screw tooling holes  23  on the bottom of the frame  20 , and one side of the frame  20  has a protruding tube base  24  that corresponds to the through opening  150  of one side wall  15  of the container bag  10 , and a concave ring edge  25  is placed on the outside of the protruding tube base  24 , and a through hole  26  in the center offers a power cord socket  27  to go through (see  FIG. 5 ). 
   There is also a fixation ring sleeve  30 , which is ring like, and the ring hole  31  in the middle can be connected to the outside of the through opening  150  of the container bag that protruding tube base  24  on the frame  20  mentioned above comes out, and convex ring edge  32  that is in the ring hole  31  can be locked in with the concave ring edge  25  of the protruding tube base  24  (see  FIG. 5 ). 
   The device also has a conductive plate  40 , which is metal plate, has outer diameter that fits in the frame  20  mentioned above, and the conductive plate  40  has a convex surface  41  that fits the convergent opening  21  of the frame  20  (see  FIG. 6 ). 
   There is a printed electrothermal plate  50 , which is also called MYLAR electrothermal plate, and it is connected (such as adhesive method) to the bottom of the conductive plate  40  mentioned above, and compare to the conventional wound type electrothermal plate and etching electrothermal plate, this printed electrothermal plate  30  is has the advantages of energy saving, fast heating, small and light (see later article for detailed comparison). 
   An automatic temperature control device  60  is to be placed between the printed electrothermal plate  50  mentioned above and the frame  20 , is connected to the printed electrothermal plate  50  and the power cord socket  27  by a conductive cable  61 ; the automatic temperature control device  60  shuts off automatically when the temperature reaches a certain high temperature (such as 70°), and turns on automatically when the temperature reaches a certain low temperature (such as 60°). 
   An insulating lining  70  is to be placed inside the printed electrothermal plate  50  mentioned above, insulates the heat generated by the printed electrothermal plate  50 ; and the insulating lining  70  may be made of foam and ethylene vinyl acetate copolymer (EVA). 
   A bottom plate  80  is to be sealed to the divergent opening  22  of the frame  20 , and there are passage holes  81  on the bottom plate  80  that corresponds to the screw tooling holes  23  on the divergent opening  22  of the frame  23 , which are connected by bolts  82 ; and there are several protruding rods  83  that are spaced out on the bottom of the bottom plate  80 , which are to go through the through holes  140  on the base wall  14  of the container bag  10 , and there are several screw holes  84  on the bottom of the protruding rods  83 . 
   Several foot mounts  90  are to be placed on the base wall  14  of the container bag  10 , and the foot mounts  90  mentioned above have through holes, and the top of the through hole  91  of each mount  90  can be connected to the protruding rods  83  that are on the base wall  14  of the container bag  10  through the bottom plate  80  mentioned above, and put the bolts  92  from the bottom of the foot mounts  90  through the through holes  91  of the foot mount to be locked into with the screw hole  84  of the protruding rod  83  and connect the foot mount  90  and bottom plate and container bag  10  (see  FIG. 6 ). 
   There is an in-car charging cable  100 , which includes a charging head  101  of a car cigarette lighter, and a conductive plug  102  of the power cord socket  27  mentioned above to be the charging components of the thermos device of the present invention. 
   Through the above structure and design, the thermos bag disclosed in the present invention can be used to store objects under the circumstances where the thermos functions are not used; when the heating function is desired, place the food that is desired to be heated into the containing space  11  of the container bag  10 , and use the in-car charging cable  100  to connect the car cigarette lighter and power cord socket  27 , and start the printed electrothermal plate  30  to heat up the food, at this time, the automatic temperature control device  60  can adjust to the temperature desired automatically to prevent overheat and to ensure the safety of using it; it makes a thermos bag that is easy to carry and easy to operate. 
   One point needs to be added, the detailed comparison between the printed electrothermal plate  30  and the conventional wound electrothermal plate and etching electrothermal plate: 
   1. Wound Electroplate: the manufacturing process is complicated, the wire design can only be series connection, no temperature coefficient, the impedance is fixed (when the temperature increases the impedance increases, therefore, it is energy consuming), and the temperature rises slowly. 
   2. Etching electroplate: the manufacturing process is complicated, the chemical solution has environmental issues, the wire design can only be series connection, no temperature coefficient, the impedance is fixed, therefore, the temperature rises slowly. 
   3. The printed electrothermal plate: the process is simple, and the wire design can be series-parallel connection, and it has temperature coefficient, and the impedance is in direct proportion with the temperature (when the temperature increases, the impedance decreases, therefore, it is energy saving), the temperature rises fast. 
   Therefore, the thermos bag in the present invention uses the printed electrothermal plate to be its thermos device, which has the advantages such as energy saving, temperature rises fast, small and light.