Abstract:
A container that experiences vibrations when transported allows an inner container which defines a chamber holding a substance to move relative to an outer shell under the influence of vibrations. An energy generator such as a magnet and a corresponding coil or a piezoelectric generator that does not move with the inner container is juxtaposed with the inner container to cause an electrical current to be introduced in the inner container when the inner container moves relative to the magnet. The electrical current is dissipated as heat to transfer heat into the substance in the chamber.

Description:
FIELD OF THE INVENTION 
       [0001]    The present application relates generally to vibrational energy harvesting heaters in double container systems for heating fluid or other substances in the inner container using relative motion between the inner container and outer container. 
       BACKGROUND OF THE INVENTION 
       [0002]    Double container systems are used for various purposes. An example non-limiting purpose is for fluid bottles to keep the fluid insulated and thus less likely to cool when in the inner container, owing to the insulative qualities of the arrangement. As understood herein, such fluid still cools down. As also understood herein, many such double container systems are intended to be used in moving and vibrational environments, and principles of this application leverage that fact. 
       SUMMARY OF THE INVENTION 
       [0003]    Although a simple fluid container system is used as an example environment in which present principles may be employed, it is to be understood that present principles apply equally to other container systems, indeed, which may seek to keep not only fluid warm but also foodstuffs or other substances. For example, present principles may be used in containers on trucks or other vehicles that hold diesel or other fuel, to increase the temperature of the diesel or other fuel. 
         [0004]    Accordingly, a container system has an outer container and an inner container defining a chamber for holding an item to be heated. The inner container is movable within the outer container when the container system vibrates or is subject to accelerations. One or more magnets are supported by the outer container and are electromagnetically coupled to at least a portion of the inner container to generate heat within the chamber when there is relative motion between the inner and the outer container. 
         [0005]    In another embodiment a piezoelectric generator is connected to the end of the inner container, which mechanically impacts the outer container causing electrical current to be generated when impacted. The generated electrical current is feed into the attached coil that is wound around the inner container thereby heating the inner container and the contents. 
         [0006]    If desired, a spring may be sandwiched between the respective bottoms of the containers to promote relative motion between the containers. In some embodiments an elastic joining element such as a rubber or plastic boot couples the inner container to the outer container. 
         [0007]    In some implementations the inner container has no heater element and is ferromagnetic. In other implementations a heater element is within the chamber for generating heat under the influence of current flowing there through responsive to relative motion between the heater element and magnet. No coils may be interposed between the heater element and the magnet. Or, an outer pickup coil may surround the inner container and is electrically connected to the heater element. 
         [0008]    In another aspect, an apparatus that experiences vibrations when transported includes a first inner container which defines a chamber configured for holding a substance. One or more magnets that do not move with the first container are juxtaposed with the first container to cause an electrical current to be introduced on or in the first container when the first container moves relative to the magnet. The electrical current is dissipated as heat to transfer heat into the substance in the chamber. 
         [0009]    In another aspect, an apparatus that experiences movements when transported includes a first inner container which defines a chamber configured for holding a substance and an energy transducer that does not move with the first container. The energy transducer is juxtaposed with the first container to transform motion between the energy transducer and the first container to heat which is introduced on or in the first container when the first container moves relative to the energy transducer. The energy transducer may be a piezoelectric element or an electro-magnetic combination including a magnet. 
         [0010]    The details of the present invention, both as to its structure and operation, can best be understood in reference to the accompanying drawings, in which like reference numerals refer to like parts, and in which: 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a cross-sectional view in elevation of a first embodiment in which a cylindrical magnet in an outer container of a double container system is coupled to a heater coil within an inner fluid container of the system through an outer coil that surrounds the inner container and that is connected to the heater coil, with a bottom spring to promote vibration between the two containers, with some details of the upper closure not shown in cross-section; 
           [0012]      FIG. 2  is a cross-sectional view in elevation of a second embodiment that is in all essential respects identical too the first embodiment shown in  FIG. 1  except the bottom spring is omitted, with some details of the upper closure not shown in cross-section; 
           [0013]      FIG. 3  is a cross-sectional view in elevation of a third embodiment in which a magnet in an outer container of a double container system is coupled to a heater coil within an inner fluid container of the system directly through the magnetically permeable wall of the inner container, with some details of the upper closure not shown in cross-section; 
           [0014]      FIG. 4  is a cross-sectional view in elevation of a fourth embodiment in which strip magnets in an outer container of a double container system are directly coupled to the wall of a ferromagnetic inner fluid container of the system, with portions of the upper closure cut away for clarity; 
           [0015]      FIG. 5  is a cross-sectional view in elevation of an embodiment in which magnets in an outer container of a double container system are directly coupled to the wall of a ferromagnetic inner fluid container of the system, with the upper ends of the containers not being coupled using elastic structure but rather freely movable relative to each other, showing an optional bottom spring; 
           [0016]      FIG. 6  shows an alternate embodiment using piezoelectric principles; and 
           [0017]      FIG. 7  illustrates a system for heating diesel fuel. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0018]    Referring initially to  FIG. 1 , a container system  10  includes an outer container  12  and an inner container  14  defining a chamber  16  for holding an item to be heated. In the example shown, the containers  12 ,  14  are coaxial with each other and the inner container  14  is substantially enclosed by the outer container  12  except at the top of the inner container. The outer container may be plastic, metal such as aluminum or steel, or a composite material. The inner container  14  may be plastic, metal such as aluminum or steel, or a composite material. Typically, the inner container is thermally insulative and an insulating air gap  18  may be established between the side walls of the containers  12 ,  14  as shown. The containers  12 ,  14  may have cylindrical side walls as shown. 
         [0019]    In the embodiment shown in  FIG. 1 , the inner container  14  is movable and more preferably is axially reciprocable within the outer container  12  when the container system  10  vibrates. This is important in the example of  FIG. 1  because one or more magnets  20  are supported by the outer container  12  and are electromagnetically coupled a portion of the inner container  14  to generate heat within the chamber  16  when the inner container  14  moves relative to the outer container  12 . In the example shown, the magnet  20  is a single cylindrical magnet that is supported on the inside side wall of the outer container  12 , extending axially more than half the length of the inner container  14  as shown. However, as discussed further below one or more bar magnets may be used. When no outer container is provided the magnet  20  may be mounted outside the inner container  14  on a nearby surface with which the inner container  12  moves relatively under the influence of vibrations. The magnet  20  may be mounted by means of fasteners such as screws or by adhesives or other means. 
         [0020]    To promote vibrational reciprocation of the inner container  14  relative to the outer container  12 , a spring  22  may be sandwiched between the containers to promote relative motion between the containers. In the embodiment of  FIG. 1  the containers define respective bottoms  24 ,  26  and the spring  22  is sandwiched between the bottoms  24 ,  26 . The spring may be a coil spring in compression or a leaf spring or indeed other spring structure such as a resilient foam layer. However,  FIG. 2  shows a container system  100  that in all essential respects is identical to the container system  10  shown in  FIG. 1  except no spring is included. 
         [0021]    On the opposite ends of the containers  12 ,  14 , the containers  12 ,  14  may be joined, in the example of  FIG. 1 , by an elastic joining element  28 . In the embodiment shown, the elastic joining element  28  is a rubber or plastic boot that is ring-shaped and that connects the open circular top periphery  30  of the inner container  14  to the open circular top periphery  32  of the outer container  12  as shown. It may now be appreciated that owing to this elastic coupling the inner container  14  can move axially in the outer container  12  when the container system  10  is subject to vibrations. 
         [0022]    In the embodiment shown in  FIG. 1 , a heater element  34  is disposed within the chamber  16  for generating heat under the influence of current flowing there through responsive to relative motion between the heater element  34  and magnet  20 . In the embodiment shown, the heater element  34  includes a coil of resistive wire arranged in a cylindrical pattern on the inside side wall of the inner container  14 . The heater element may be made of steel, tungsten, or indeed even copper but it is preferable that the heater wire be made of material that is more electrically resistive rather than less to promote the generation of dissipative heat when electrical current passes through the heater element. The wire or wires of the heater element may be embedded in a cylindrical thin plastic sleeve and bonded to the inside surface of the inner container  14  for convenience. 
         [0023]    In the embodiment of  FIG. 1 , an outer pickup coil  36  surrounds the inner container  14 . The pickup coil  36 , which may be wrapped around the outside of the cylindrical side wall of the inner container  14  as shown, is electrically connected to the heater element. In the example shown, the pickup coil  36  is connected to the heater element  34  via upper and lower leads  38 ,  40  which respectively extend through upper and lower side channels  42 ,  44  formed in the inner container  14 . In other embodiments the inner container  14  may be electrically conductive and the pickup coil  36  may be connected to the heater element  34  through the inner container  14  material. 
         [0024]    Briefly referring to  FIG. 3 , a container system  200  is in all essential respects is identical to the container system  10  shown in  FIG. 1  except that no pickup coil is interposed between a heater element  202  within the inner container  204  and a magnet  206 . In this embodiment the inner container  204  is magnetically permeable so that the magnet  206  is electromagnetically coupled directly to the heater element  202 . 
         [0025]      FIG. 4  takes it a step farther, in which a container system  300  includes no pickup coil and no heater element. Instead, an inner container  302  is ferromagnetic so that the magnetic coupling is between a magnet  304  and the inner container  302  walls, generating current in the walls that is dissipated as heat into the chamber  306  when the inner container  302  vibrates relative to an outer container  308 . Note that another difference between the systems  10  and  300  of  FIGS. 1 and 4  is that plural elongated bar magnets are used to establish the magnet  304  in  FIG. 1 . 
         [0026]    Referring back to  FIG. 1 , particularly when the substance within the chamber  16  is a liquid for applications in which the container system  10  is mounted on a bicycle or other moving conveyance, a closure  50  is provided to close the open end of the inner container  14 . In the example shown the closure  50  includes a cylindrical stopper  52  merging into inwardly tapering upper shoulders  54  and terminating at an opening  56 , which may be selectively blocked by a familiar plunger-type device  58 . Alternatively, the closure  50  may be threadably engaged with the neck of the outer container  14 . 
         [0027]    Having completed the description of  FIG. 1  and having attended to  FIGS. 2-4 , attention is now drawn to  FIG. 5 , which shows a container system  400  in which an outer container  402  supports an inner container  404 , but in which the upper peripheries of the containers  402 ,  404  are not coupled together by an elastic boot. Instead, the upper portions  406 ,  408  of the containers  402 ,  404 , which may taper inwardly and upwardly as shown to establish slanted shoulders, are spaced from each other and are not connected together at all. The only limit to the upward motion of the inner container  404  within the outer container  402  is by operation of the outside surface of the upper portion  408  of the inner container  404  abutting the inside surface of the upper portion  406  of the outer container  402 . 
         [0028]    If it is desired to couple the containers  402 ,  404  together, a bottom spring  410  may be disposed between the container bottoms as shown, although this spring is optional. In effect, the inner container  404  may be allowed to freely move within the outer container  402  constrained only by the walls of the outer container  402 . The upper open neck  412  of the inner container  404  may extend upwardly beyond a top opening  414  in the outer container  402  if desired, a configuration that may be implemented in any of the previous embodiments where appropriate. 
         [0029]      FIG. 6  illustrates an embodiment of the present invention employing a piezo-electric generator. Illustrated is an inner container  502 , with the piezo-electric generator  500 , attached to the end portion of the inner-container. Attached to the piezo electric generator  500 , is a coil assembly  501 . There are two leads coming from the piezo-electric generator  500 , to the coil assembly  501 . An outer-container  515  comprises a flexible supporting neck  530  that attaches the inner-container to the outer-container but allows for vibrational motion between the two components. The outer container comprises an end surface,  520 , which communicate with the piezo-electric generator  500 , and a cap  525 , for securing to the container system. 
         [0030]    When the system is subjected to motion, the inner container  502 , is allowed to move relative to the outer-container  515 , by means of the flexible supporting neck element  530 , which allows for a degree of inertial isolation between the inner container  502 , and the outer container  515 . The piezo-electric generator  500  is attached to the end of the inner container  502  which when subjected to accelerations and vibrational motion impacts with the end of portion  520  of the outer container assembly  515 . These impacts are converted to electro-motive forces in the piezo electric generator  500 , which powers the coil assembly  501 , thereby heating the inner-container  502  and the contents contained therein. 
         [0031]      FIG. 7  illustrates an embodiment of present principles for use in a diesel fuel tank or fuel tank for use in transportation vehicles such as cars, trucks, airplanes, and ships. The system heats the fuel so to provide improved operations especially in cold environments. 
         [0032]    The fuel tank comprises an inner container  600 , which contains the fuel, and an outer-assembly  620 , which has attached to its inside a set of permanent magnets  602  and provides the mechanical attachments to the vehicle. A coil system  604 , is wrapped around the inner-container  600  and is connected to a resistive heater  610  that is located on the neck of the inner container  600 , as illustrated. Connecting the inner-container to the outer-assembly is the flexible neck element  615 . Illustrated is a mechanical roller guide arrangement  630  allowing the two moving parts to translate smoothly. 
         [0033]    The inner-container has a coil system  604  which communicates with the magnetic system,  602 , thereby generating electro-motive force which is applied to the resistive heater  610  located at the neck output of the fuel tank. 
         [0034]    While the particular ENERGY HARVESTING CONTAINER is herein shown and described in detail, it is to be understood that the subject matter which is encompassed by the present invention is limited only by the claims.