Abstract:
A heating and cooling mechanism disposed between a trim cover and foam pad of a seat assembly for increasing the thermal conductivity of the seat assembly. The mechanism comprises at least a pair of spaced apart elongated thermally conductive heat pipes and a thermally conductive distribution pad coupled between each of the heat pipes for disbursing thermal energy about the pad and between the heat pipes. A thermoelectric generator is electrically coupled to each of the heat pipes for generating thermal energy to the heat pipes for distribution across the pad.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. Provisional Application No. 62/214,383, filed on Sep. 4, 2015. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a seat assembly in an automotive vehicle having a heating and cooling mechanism and an improved thermally conductive trim cover assembly. More particularly, the invention relates to a thermoelectric mechanism for rapidly heating and cooling the surface of the seat assembly for seat occupant comfort and a thermally conductive trim cover assembly for efficiently dispersing the heat from the mechanism to and from the surface of the seat assembly. 
         [0004]    2. Description of Related Art 
         [0005]    Automotive vehicles include one or more seat assemblies having a seat cushion and a seat back for supporting a passenger or occupant above a vehicle floor. The seat assembly is commonly mounted to the vehicle floor by a riser assembly. The seat back is typically operatively coupled to the seat cushion by a recliner assembly for providing selective pivotal adjustment of the seat back relative to the seat cushion. 
         [0006]    It is commonly known to provide seat assemblies with heating and cooling mechanisms for selectively heating and cooling the surface of the seat for seat occupant comfort. These known heating and cooling mechanisms are typically independent mechanisms. For example, it is common to provide an electric wire heating pad between the foam pad and trim cover of the seat cushion or seat back which is electrically actuated by the power from the vehicle battery to electrically charge the heating pad and provide heat to the surface of the seat cushion or seat back. It is also known to provide fans and air ducts to force cool air through the foam pad and trim cover and provide cool air to the surface of the seat cushion or seat back. It is also known to provide fans and ducts to draw warm, moist air away from the seating surface to provide a gradual cooling effect. 
         [0007]    However, current heating and cooling mechanisms require a fair amount of time and power to generate sufficient heat or cool air to affect the temperature of the seat assembly and the desired comfort for the seat occupant. 
         [0008]    It is desirable, therefore, to provide a heating and cooling mechanism which can rapidly or almost instantly provide heating or cooling to the surface of the seat assembly. It is also desirable to provide an improved thermally conductive trim cover assembly for dispersing the heat to and from the surface of the seat assembly. 
       SUMMARY OF THE INVENTION 
       [0009]    A heating and cooling mechanism is provided to be disposed between a trim cover and foam pad of a seat assembly for increasing the thermal conductivity of the seat assembly. The mechanism comprises at least a pair of spaced apart elongated thermally conductive heat pipes and a thermally conductive distribution pad coupled between each of the heat pipes for disbursing thermal energy about the pad and between the heat pipes. A thermoelectric generator is electrically coupled to each of the heat pipes for generating thermal energy to the heat pipes for distribution across the pad. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    Advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein: 
           [0011]      FIG. 1  is a schematic perspective view of a seat assembly for an automotive vehicle; 
           [0012]      FIG. 2  is a perspective view of a seat cushion of the seat assembly showing a cellular foam pad with a thermoelectric mechanism according to one embodiment of the invention; 
           [0013]      FIG. 3  is an enlarged view of the thermoelectric mechanism of  FIG. 2 ; 
           [0014]      FIG. 4  is a perspective view of a thermally conductive plus pad of the trim cover assembly according to one embodiment of the invention; 
           [0015]      FIG. 5  is a perspective view of a thermally conductive plus pad of the trim cover assembly according to an alternative embodiment; 
           [0016]      FIG. 6  is a perspective view of a thermally conductive plus pad of the trim cover assembly according to another alternative embodiment; 
           [0017]      FIG. 7  is a perspective view of a thermally conductive plus pad of the trim cover assembly according to yet another alternative embodiment; 
           [0018]      FIG. 8  is perspective view of a copper mesh plus pad and thermally conductive trim cover according to an alternative embodiment of the trim cover assembly; 
           [0019]      FIG. 9  is a top view of the thermally conductive trim cover of  FIG. 8 ; and 
           [0020]      FIG. 10  is a bottom view of the thermally conductive trim cover of  FIG. 8 . 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0021]    Referring to the Figures, wherein like numerals indicate like or corresponding parts throughout the several views, a seat assembly  10  for use in an automotive vehicle is generally shown in  FIG. 1  and includes a generally horizontal seat cushion  12  and a generally upright seat back  14  for supporting a seat occupant within the vehicle as is commonly known in the art. The seat back  14  is typically operatively coupled to the seat cushion  12  by a recliner assembly  16  for providing pivotal movement between an upright seating position and a plurality of reclined seating positions. 
         [0022]    Each of the seat cushion  12  and seat back  14  commonly include a molded resilient cellular foam pad  18  encased in a trim cover assembly  19 , commonly of cloth, vinyl, or leather. The present invention relates to a heating and cooling system operatively coupled to the seat cushion  12  and/or seat back  14  for selectively heating and cooling the surface of the seat assembly  10 . A heating and cooling system for a vehicle seat assembly generally comprises three components affecting the system: the engine, or heating and cooling mechanism; an optional plus pad on the surface of the foam pad; and a trim cover, often of leather. The plus pad is typically attached to the bottom surface of the trim cover forming a combined trim cover assembly  19 . Each of the components of the heating and cooling system must be addressed to maximize the efficiency and effectiveness of the system. 
         [0023]    First, referring to  FIGS. 2 and 3 , a foam pad  18  of a seat cushion  12  is shown with the trim cover assembly  19  removed. A heating and cooling mechanism  20  is coupled to the top surface  21  of the foam pad  18  and includes a pair of spaced apart and generally parallel heat pipes  22  each positioned in and along foam trenches  23  formed in the foam pad  18  so as to not interfere with the comfort of the seat assembly  10 . The heat pipes  22  could also be positioned at other orientations and locations on the foam pad  18  without varying from the scope of the invention. For instance, the heat pipes  22  could be oriented side-to-side and positioned at the seat bight line  25  or at the front portion of the cushion foam pad  18 . The heat pipes  22  may include copper piping or other thermally conductive material pipe, such as aluminum, silver, or graphite. A thermoelectric component or generator  24 , such as a Peltier device, is electrically connected to each heat pipe  22  for rapidly heating or cooling each of the heat pipes  22 . That is, the thermoelectric generator  24  includes positive and negative electrical feed wires  27 ,  29  connected to a switch  28  and a power source (such as the vehicle battery B) within the vehicle for providing electrical current to the generator  24 . Further, providing current in one polarity to the thermoelectric generator  24  produces heat and reversing the polarity produces cooling both of which are transferred to the respective heat pipes  22 . It should be appreciated that in this manner the thermoelectric generators  24  may be positioned remotely from the heat pipes  22  and also remotely from the seating surface. A distribution pad  26  is connected and suspended between the spaced apart heat pipes  22  to effectively transfer heat away from or to the surface of the seat cushion  12 . The distribution pad  26  in the preferred embodiment is preferably a woven pad of expanded graphite material strands  31  mixed with a cotton core of yarn to create a very conductive pad of material. That is the strands  31  may include a core of cotton yarn material wrapped or encased in a layer of expanded graphite material. A plurality of the strands  31  are then interwoven in a chain link manner as shown in  FIGS. 2 and 3  to form planar woven distribution pad  26 . It should be appreciated that the distribution pad  26  may comprise other highly conductive woven materials such as silver, aluminum, or other conductive materials. The heat pipes  22  are fed through the weave or loops of the pad  26  formed by the interwoven strands  31  to create contact between the heat pipes  22  and the distribution pad  26  for transferring the thermal conductivity (heat or cold) from the heat pipes  22  to the pad  26 . Finally, the interwoven strands  31  forming the distribution pad  26  create a flexible and resilient pad  26  between the foam pad  18  and trim cover assembly  19  so as to conform to the shape and contour of the top surface  21  of the foam pad  18  and not be detected by the seat occupant. 
         [0024]    The thermoelectric mechanism  20  provides rapid and almost instantaneous heating or cooling to the seat assembly  10  with low power consumption. For example, the mechanism  20  requires approximately 60 watts of power to generate preferred heating and approximately 40-90 watts of power in reverse polarity to generate preferred cooling. 
         [0025]    Referring to  FIGS. 4 and 5 , a thermally conductive plus pad is shown at  30  forming part of the trim cover assembly  19 . That is, a trim cover assembly typically includes a trim cover of cloth, vinyl or leather and a foam plus pad attached to the bottom surface of the trim cover for encasing the foam pad  18  as is commonly known in the seating art. The thermally conductive plus pad  30  is an alternative to the traditional foam plus pad attached to the trim cover  31 , or seated between the trim cover  31  and the cushion foam pad  18 , and includes a thin layer of polyurethane cellular foam padding  32  with an attached top layer or sheet of cloth  34  and a continuous strand of graphite yarn  36  woven and sewn through the foam padding  32  and top cloth layer  34  to increase the thermal conductivity of the plus pad  30 . The graphite yarn  36  is approximately 2 mm in diameter, however the diameter of yarn may vary. The graphite yarn  36  is also soft and flexible such that it can be woven through the foam padding  32  and also be relatively undetected from the top surface of the seat cushion  12 .  FIG. 4  shows one preferred weave pattern of the graphite yarn  36  and  FIG. 5  shown an alternative weave pattern of the graphite yarn  36 . However, it should be appreciated that the graphite yarn  36  is one continuous long strand woven through the padding  32  to provide a continuous thermal pathway and increase or improve the overall thermal conductivity of the entire plus pad  30 . It should be appreciated that the graphite yarn  36  may comprise other highly conductive woven materials such as silver, aluminum, or other conductive materials. 
         [0026]    Referring to  FIGS. 6 and 7 , alternative embodiments of a plus pad  40  are shown. The plus pad  40  includes a thin layer of polyurethane cellular foam padding  42  forming a top surface  44  and bottom surface  46 . The foam padding  42  is embedded with either, graphite yarn  48 ,  FIG. 6 , or chopped graphite flakes  50 ,  FIG. 7 , during the foaming process to create a thermal pathway through the graphite material between the top and bottom surfaces  44 ,  46  of the foam padding  42  and again increase the overall thermal conductivity of the plus pad  40 . It should be appreciated that the graphite yarn  48  or graphite flakes  50  may comprise other highly conductive materials such as silver, aluminum, or other conductive materials. 
         [0027]    Still further, referring to  FIG. 8 , yet another alternative embodiment is shown wherein the plus pad is replaced entirely with a sheet of woven copper mesh material forming a thermally conductive mesh pad  60 . The copper mesh is comprised of interwoven strands or copper wire material to form the continuous woven sheet of the mesh pad  60  as shown in  FIG. 8 . The length and diameter of the copper wire may vary without altering the scope of the invention. The copper mesh pad  60  is highly thermally conductive, flexible, and resilient, and may be positioned between the trim cover  31  and foam pad  18 . It should be appreciated that the mesh pad  60  may comprise other highly conductive woven materials such as silver, aluminum, or other conductive metals. 
         [0028]    Finally, referring to  FIGS. 9 and 10 , an improved thermally conductive trim cover is shown at  70 . The trim cover  70  of  FIGS. 9 and 10  is a sheet or skin layer of leather material. Typically imperfections in a skin layer of leather are filled with a polymer spackle spread on the back surface of the leather as is commonly known in the leather manufacturing process. In the present invention, the back surface  71  of the leather skin is spackled with a thermally conductive paste to add a layer of conductive material to the trim cover  70 . In the preferred embodiment, the thermally conductive paste is comprised of graphite and/or aluminum particles with a preferred particle size of  30  microns or less having an acrylic or urethane binder system to contain the conductive particles. It should be appreciated that the paste may also be comprised of other filler materials of high conductivity such as copper. Further, the skin of leather is often perforated with small holes therethrough to allow air circulation through the skin layer. It is also possible to fill these perforations in the skin of leather with the thermally conductive paste, as shown at  72  in  FIG. 10 , and form a conductive pathway through the perforations or holes from the bottom surface  71  to the top surface  73  of the trim cover  70 . It should be appreciated that the thermally conductive trim cover  70  may be used in combination with any of the above-described plus pads  30 ,  40 ,  60  to improve the overall thermal conductivity of the seat assembly  10 . 
         [0029]    The invention has been described in an illustrative manner, and it is to be understood that the terminology, which has been used, is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced other than as specifically described.