Abstract:
A multiple convective cushion seating and sleeping system for providing temperature modified air to multiple surfaces, such as a seating surface and a sleeping surface, with the same air cooling or heating source. The invention includes the use of tubular spacer material including tubular spacer fabric. A power unit including a heat pump and blower is in fluid communication with a first convective cushion by a first duct and with a second convective cushion by a second duct to provide the temperature modified air to both convective cushions for controllably heating or cooling multiple users. A thermoelectric heat pump, a Stirling cycle heat pump or other type of heat pump can be used. The invention includes the use or one or more valves to control the air flow to one or more of the convective cushions and provides for manual operation, electronic control and operation by a remote telecommunications unit. The invention can be utilized in vehicles, such as tractor trailers and recreational vehicles, and in buildings such as apartments, dorm rooms and houses.

Description:
RELATED APPLICATION DATA 
       [0001]    This application is a continuation-in-part of the U.S. patent application entitled “Improved Convective Seating and Sleeping Systems” filed on Jun. 19, 2007. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    This present invention relates to convective cooling and heating of seats, mattresses, mattress pads and other articles used as a cushioning device. 
         [0004]    2. Description of Related Art 
         [0005]    There are many applications and situations where it is desirable to provide for convective cooling or heating of various articles including seats, mattresses and other articles used for supporting individuals while either sitting or laying down on the article. Many of the conventional devices that have been used suffer from serious drawbacks. As one example, the resistance heated type prior art mattresses and cushions do not provide for cooling or ventilation, a major disadvantage in many parts of the world that lack adequate air conditioning. Moreover, the conventional devices are very inefficient and lack adequate control to adjust the heating or cooling temperature to satisfy the needs of the user. In addition, because of the believed negative impact on the environment, certain materials, such as Freon used for cooling purposes, are being phased out for use in air conditioning systems in many countries. 
         [0006]    Some drivers of semi-tractor trailers use a sleeper cab with a bed inside that enables the driver to sleep when necessary while on the road without incurring hotel bills. Recent legislation has mandated that diesel truck engines cannot be allowed to idle to provide electricity for an on-board air conditioning system as in the past. Conventional air conditioning space cooling systems use too much energy to run for long periods of time on the vehicle battery or batteries. 
         [0007]    In U.S. Pat. No. 6,085,369 by Steve Feher there is disclosed a selectively cooled or heated cushion and apparatus therefore and in U.S. Patent Publication No. 2006/0137099, also by Steve Feher, published Jun. 29, 2006, a convective cushion with a positive coefficient of resistance heating mode is disclosed. While each of the Feher &#39;369 patent and the Feher &#39;099 application is a substantial improvement over other known and conventional prior art techniques, there is believed to be room for improvement in apparatus and systems that provide selectively variable temperature air to convective cushions for cooling and/or heating both a seating surface and a sleeping surface with the same air cooling or heating source and in a wide variety of applications, including home, office and in vehicles. Thus, a need exists for improved systems and methods for convective cooling and heating of seats, mattresses, mattress pads and other articles. 
       SUMMARY OF THE INVENTION 
       [0008]    A multiple convective cushion seating and sleeping systems and methods for controlled convective cooling and heating for seats, mattresses, mattress pads and other articles. The invention is intended to be used in many applications, including in vehicles such as tractor trailers and recreational vehicles, and in dwellings such as dorm rooms where a chair and bed can be cooled and heated with a single cooled and/or heated air source, saving the user money and space over having to purchase and set up two separate air sources, one for the chair and one for the bed. In one or more embodiments of the invention, a single source of cooled and/or heated air is used to convectively cool and/or heat multiple surfaces, such as seating surfaces and sleeping surfaces, either individually or simultaneously. 
         [0009]    With respect to large trucks, it is known that conventional air conditioning space cooling systems use too much energy to run for eight hours on the vehicle battery or batteries. The invention advantageously uses an air convection cooled and/or heated mattress or mattress pad which is more energy efficient at cooling and eating the sleeper than a space cooling and heating device. The invention is much quieter, enabling a better sleep for light sleepers and, because of much higher efficiency, the invention can be powered by a typical truck electrical system without running the battery down. The invention saves space and weight by utilizing a single air cooling and/or heating source and with respect to use in vehicles, advantageously allows for the simultaneous use of both a convectively cooled or heated seating surface and sleeping surface when two drivers are taking turns driving and sleeping. 
         [0010]    In one or more embodiments of the invention, the invention includes a first convective cushion and a second convective cushion, each with a generally permeable top surface, an internal air flow structure and an air inlet in communication with the respective air flow structure. A power unit including a blower delivers air of selectively variable temperature and quantity to both respective air inlets for the convective cushions and the air then fans out within the respective air flow structure with some of the air permeating up through the convective cushion&#39;s top surface to cool or heat the user or users. The power unit includes a thermoelectric heat pump, a Stirling cycle heat pump or other types of heat pumps supplying cooled and/or heated air. Valves are optionally utilized to control the flow of the air from the blower to the air flow structures of the convective cushions. 
         [0011]    The air flow structures include the use of tubular spacer fabric, air flow structures such as Muller Textile&#39;s 3 Mesh or Strahle and Hess&#39; assembled woven fabric and other air flow structures known to persons skilled in the art. In embodiments of the invention, some of the air delivered to the air flow structure of the convective cushion flows toward and out air outlet vents at an end of the cushion. The present invention includes the use of a controller to selectively control the operation of the blower, the use of a remote control signal from a telecommunications unit and use of the invention with the first cushion on a conventional mattress and the second cushion attached to a seat cushion. 
         [0012]    Further embodiments of the invention include methods for delivering temperature modified air to convective cushions for convective cooling and/or heating of multiple surfaces. The methods include the steps of providing a first plenum structure, a second plenum structure, and activating a power unit in fluid communication with air flow structures within each plenum structure to deliver temperature modified air to both the first and second plenum structures and provide convective cooling and/or heating to multiple surfaces. Further embodiments include the step of placing the first plenum structure on a conventional mattress and attaching the second plenum structure to a seat cushion and include the step of installing the first plenum structure, the second plenum structure and the power unit within a vehicle. 
         [0013]    Other and further advantages and embodiments will appear to persons skilled in the art from the written description and the drawings herein. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0014]      FIG. 1  is a perspective view of one embodiment of a convective cushion of the present invention. 
           [0015]      FIG. 2  is a side elevation and section view of a convective cushion of one embodiment of the present invention. 
           [0016]      FIG. 3  is a schematic view of a version of a heat pump in one or more embodiments of the present invention. 
           [0017]      FIG. 4  is a front elevation and sectional view showing a pleat in one embodiment of the present invention. 
           [0018]      FIG. 5  is a front elevation and partial section view showing the air flow for one embodiment of the present invention. 
           [0019]      FIG. 6  is a front elevation and partial section view showing the air flow in a further embodiment of the present invention. 
           [0020]      FIG. 7  is a front elevation and partial section view showing the air flow in another embodiment of the present invention. 
           [0021]      FIG. 8  is a side elevation and partial section view of one version of a series air flow structure for one embodiment of the present invention. 
           [0022]      FIG. 9  is a side elevation and partial section view of one version of a parallel flow structure for one embodiment of the present invention. 
           [0023]      FIG. 10  is a front elevation and partial section view illustrating an embodiment of a convective cushion for use in one or more embodiments of the present invention. 
           [0024]      FIG. 11  is a side elevation and partial section view of one version of a series air flow structure with headrest for one embodiment of the present invention. 
           [0025]      FIG. 12  is a section view of a Stirling cycle device for use in one or more embodiments of the present invention. 
           [0026]      FIG. 13  is a side elevation and section view illustrating the piston, the magnetic piston ring and the magnetic bearing permanent magnet and pole assembly in a Stirling cycle device in one or more embodiments of the present invention. 
           [0027]      FIG. 14  is a front elevation and section view of the piston, magnetic piston ring and the magnetic bearing permanent magnet and pole assembly in a Stirling cycle device in one or more embodiments of the present invention. 
           [0028]      FIG. 15  is a schematic view of a version of a mobile device for use in one or more embodiments of the present invention. 
           [0029]      FIG. 16  is a schematic view of a version of a heat pump in one or more embodiments of the present invention. 
           [0030]      FIG. 17  is a schematic view of another version of a heat pump in one or more embodiments of the present invention. 
           [0031]      FIG. 18  is a perspective view of a further embodiment of a convective cushion in one or more embodiments of the present invention. 
           [0032]      FIG. 19  is an end elevation and section view of the convective cushion illustrated in  FIG. 18  used in one or more embodiments of the present invention. 
           [0033]      FIG. 20  is partial perspective view of one embodiment of the tubular spacer material in one or more embodiments of the present invention. 
           [0034]      FIG. 21  is a schematic view of one embodiment of a thermoelectric device in one or more embodiments of the present invention. 
           [0035]      FIG. 21   a  is an end elevation view of one embodiment of a blower for use with one or more embodiments of the thermoelectric device of  FIG. 21 . 
           [0036]      FIG. 22  is a schematic view of one embodiment of a thermoelectric device in one or more embodiments of the present invention. 
           [0037]      FIG. 23  is a perspective view of one embodiment of the convective cushion and seating system of the present invention. 
           [0038]      FIG. 24  is an end elevation and section view of the convective cushion in one embodiment of the convective cushion and seating system of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0039]      FIG. 1  is a perspective view of one embodiment of the convective cushion  10  as applied to a mattress for cooling and heating while a user is resting or sleeping. The convective cushion  10  includes a plenum  12  having a generally air permeable top surface  14  that is secured around a perimeter  16  to a bottom surface  18 . The bottom surface  18  is in one or more embodiments generally impermeable to air and as shown in  FIGS. 1 and 2  can be placed on a mattress  20  to make the bottom surface  18  generally impermeable. In one or more embodiments, the mattress  20  is a foam mattress, but the present invention includes the use of a futon, coil spring mattresses, inflatable mattresses or other structures made of other materials to support the plenum  12 . 
         [0040]    As shown in  FIG. 1 , the plenum  12  includes multiple pockets  22  made of a synthetic material woven into a mesh of approximately 4-6 strands per inch×4-6 strands per inch with each of the pockets  22  separately removable as part of the plenum  12 .  FIG. 1  shows three pockets  22  but other quantities and sizes of pockets  22  are within the scope of the present invention. 
         [0041]    Each of the pockets  22  contains tubular spacer material  30 . The present inventor&#39;s U.S. Pat. Nos. 6,085,369 and 6,263,530 pioneered the use of tubular spacer fabric as an air flow structure for seats, mattresses, mattress pads and other articles of furniture that can be sat on or laid down upon. Although one embodiment of the invention utilizes the same tubular spacer fabric as described in the inventor&#39;s issued U.S. Pat. Nos. 6,085,369 and 6,263,530, it is within the scope of the present invention to utilize other air flow structures such as Muller Textile&#39;s 3 Mesh or Strahle and Hess&#39; assembled woven fabric and other air flow structures, however there may be substantially reduced levels of performance when compared to the tubular spacer fabric disclosed in the above issued U.S. patents. 
         [0042]    The pockets  22  secure the multiple sections of the tubular spacer material  30  close together while still allowing air to flow from one end of the plenum  12  to the other end of the plenum  12  through pockets  12  via the tubular spacer material  30 . The pockets  22  may be arranged so that the longitudinal axes of the tubular spacer material in the pockets  22  are all aligned to allow substantially uninterrupted flow of air. If the pockets  22  were made of standard cotton sheeting, as the upper and lower layers are made, the pressure drops across the pocket walls between the tubular spacer material  30  layers would be too high and functional air flow within the plenum  12  would not be possible using a small, light, cost-effective and quiet main blower. 
         [0043]    The use of multiple pockets  22  containing tubular spacer material  30  in one or more embodiments instead of one single mattress sized panel allows for the tubular spacer material  30  to be easier to handle in smaller pieces and it is generally not feasible to launder a single mattress size piece of tubular spacer material  30  in a standard washing machine. A single queen size piece of tubular spacer material  30  is not impossible to handle, but is much more difficult to handle than smaller pieces, even if laundering by washing in a shower or bathtub or a large washtub. For larger beds, such as King, California King, and larger, it may be more convenient to divide the plenum  12  into more pockets  22  to facilitate shipping, handling and laundering and these embodiments are within the scope of the present invention also. 
         [0044]    As shown in  FIG. 1 , one or more embodiments include an air inlet nozzle  40  to deliver air to the plenum  12 . Air enters the mattress pad through the air inlet nozzle  40  and fans out within the tubular spacer material  30 , with some of the air permeating up through the top surface  14  of the plenum  12  as the air flows toward an outlet at the opposite end of the plenum  12 , which is shown as air outlet vents  41  in  FIG. 1 . This air flow surrounds the user underneath and to a lesser extent, on the sides, with an atmosphere or micro-environment of cooled or heated air, depending upon which mode is chosen. The air inlet nozzle  40  in one or more embodiments is removable and may be removed prior to machine washing, by sewing or otherwise attaching a small plastic adaptor to the edge of a cloth cover, allowing the air inlet nozzle  40  to be snapped on and off. Further embodiments of the invention include an extra layer  24  as shown in  FIG. 1  which can be placed over a pocket  22  adjacent to the air inlet nozzle  40 . The extra layer  24  can provide temperature control for the space adjacent to the air inlet nozzle  40  by limiting air flow through the top surface  14  in the area of the extra layer  24 . 
         [0045]    In one or more embodiments, the blower  46  delivers air to the air inlet nozzle  40  which may include a flexible hose portion as shown in  FIG. 1 , and the air delivered from the blower  46  to the air inlet nozzle  40  is of a selectively variable temperature, a selectively variable quantity or a selectively variable temperature and quantity. In additional embodiments, the blower  46  includes a decorative face plate  48  illustrated in  FIG. 1  to display colors and/or designs that a user may select to mask the blower  46 , which may be under the bed or at the end of the bed in the event it does not fit under the bed. If under the bed, there needs to be an open path to enable air flow to the blower  46 . 
         [0046]    In one or more embodiments, the face plate  48  which is removable from the blower  46  and secured to the blower  46  by plastic fittings, snap-on connectors or other securing mechanisms that allow the face plate  48  to be removed, all of which are known to persons skilled in the art and included within the scope of the present invention. The face plate  48  may cover all or as shown merely a portion of the blower  46 , and be a single color such as a neutral color or a dark color or may be a combination of colors. The face plate  48  may be made of one or more materials including plastic, wood or a combination of materials. The face plate  48  may also be a design such as a wood appearing veneer as selected by the user to present a more attractive appearing article to persons viewing the blower  46 . Embodiments of the present invention allow a user to selectively change the face plate  48  as desired for a variety of color, color combinations and design arrangements that the user may wish to select. 
         [0047]    In one or more embodiments shown in  FIG. 1  and  FIG. 2 , a fitted sheet  32  secures the pockets  22  together in a similar way a fitted sheet with an elastic band fits securely onto a mattress by gripping around the bottom edge. An outer top cover  34  may also be sewn to the underlayer around the perimeter at the top of the plenum  12  to further secure the pockets  22 . 
         [0048]      FIG. 2  shows a closure  36  along a long side edge of the plenum  12 . This closure  36  may be made of hook and loop fastener or may be a ZIPPER running the length of the edge. The closure  36  may also be a plastic slide, snaps or buttons. In further embodiments, an elastic band  38  can secure the top layer  34  to the mattress  20 . 
         [0049]      FIG. 2  shows an alternative embodiment with an air inlet duct  42  that is molded into a foam mattress  20 . The outlet air duct  44  is molded into the foam mattress  20  and allows air that does not escape through the top surface  14  of the plenum  12 , and which flows longitudinally within and through the tubular spacer material  30 , to flow out of the cushion  10 . 
         [0050]      FIG. 3  shows a schematic view of an embodiment of the convective cushion  10  with a thermistor or thermocouple  50 . As illustrated in  FIG. 3 , data from the thermistor or thermocouple  50  is communicated to a controller  52 , which may be either a variable amplitude Stirling Cycle cooler piston drive controller or Peltier thermoelectric heat pump control circuit, to either increase or decrease the amplitude of the Stirling Cycle piston displacement or the power level delivered to the thermoelectric heat pump, and hence the cooling power delivered to the cushion  10  as a function of a preselected temperature. 
         [0051]    In one or more embodiments, the thermistor or thermocouple  50  may be placed on the underside of the top cover  34  of the embodiment shown in  FIGS. 1 and 2  adjacent to the tubular spacer material  30 . In other embodiments of the invention, the thermocouple  50  is placed in a seat backrest, a seat rest or may be placed anywhere else in the conditioned air stream to provide temperature feedback to the controller  52  and use conditioned air temperature at any given point in the stream as a reference temperature for the controller  52 . 
         [0052]    In further embodiments of the invention, the thermistor or thermocouple  50  is of the miniature type in order to minimize sensor mass and enable more rapid and sensitive reaction to changes in cover cloth temperature. 
         [0053]    In cooling mode, if the user is large and hot, it will take longer for the sensor to cool down because the user&#39;s body heat will prevent the sensor from cooling down to the temperature of the air flowing by on the inside of the tubular spacer material  30 . But if the user is small and relatively cool, or if the user has cooled down after sitting on the seat or lying on the mattress pad, the sensor will begin to read more of the internal air temperature, and this change in value can be interpreted as a signal to reduce cooling power in order to avoid overcooling. 
         [0054]    The embedded thermocouple or thermistor  50  is applicable to both cooling and heating modes in the improved Peltier thermoelectric type convective cushion  10  because heating mode is a function of input power to the thermoelectric device and the air flow volume through the heat pump. 
         [0055]    Also as shown in  FIG. 3 , one or more embodiments include a double pole, double throw switch  54  that is arranged to switch a resistor  56  in and out in series with the basic main blower control potentiometer. The basic control potentiometer controls the speed of the main blower, which controls the cooling or heating power delivered to the cushion  10  at a given temperature change. The variable amplitude piston driver controller also controls the power of the Stirling machine, but another method of control, especially in heating mode, is to control the amount of air blown through the cushion  10  regardless of air temperature change using the double pole, double throw switch  54 . 
         [0056]    It can be appreciated in  FIG. 3  that the trim resistor, which drops the speed of the main blower in heating mode, is only switched in circuit for a Stirling Cycle machine when heating mode is selected. It is then in series with the main blower control potentiometer, in order to maintain user control of main blower speed and air flow within the reduced heating mode blower speed range. Note that the double pole, double throw switch  54  is connected to the main power switch, and that a jumper is used to show that the two poles connect to the main switch. The diagonal line in the double pole, double throw switch  54  in  FIG. 3  represents the mechanical connection between the two poles, which are activated by a common solenoid or other actuator. 
         [0057]      FIG. 4  shows an embodiment of the convective cushion  10  for use in seats, beds or other articles of furniture having deep lateral and longitudinal styling pleats. Pleats are often used by furniture designers to enhance the appearance of the outside surface of seats and cushions, but present a problem when one is trying to blow air longitudinally within the tubular spacer material  30  located just under a body cloth or leather cover for a seat or cushion. 
         [0058]    For example,  FIG. 10  shows one of the inventor&#39;s previous embodiments of a seat with tubular spacer material. The styling pleat shown in  FIG. 10 , a surface longitudinal pleat  58 , is relatively shallow and is located superficially over the tubular spacer material  30  layer and the depth of the pleat is defined by the thickness of the pad between the outer cloth or leather cover material and the tubular spacer material  30  layer. 
         [0059]      FIG. 4  is an illustration of an embodiment of the convective cushion  10  of the present invention in a seat with a deep longitudinal pleat  62  running from the seat bite line, or seat hinge point  64 , to the front edge of the seatrest  66 . This is accomplished in one embodiment by dividing the tubular spacer material  30  into two halves, with a longitudinal gap running down the middle as shown in  FIGS. 4 and 5 . The longitudinal gap leaves room for Lister wires  68  and hog rings  70  to assemble the apparatus into a seat. One wire  68  is anchored into the foam base  72 , and the other wire is sewn into the seat cover pleat  62  in such a way as to allow the two wires to be clamped loosely together with the hog ring  70  shown. One or more embodiments include an optional bolster  76  which is shown in  FIG. 4 . 
         [0060]    In one or more embodiments, two or more hog rings  70  are used on each Lister wire assembly  68 . The Lister wire assembly  68  pulls a cover  74  down deeply into the gap, creating a deep styling pleat  62  that is securely anchored to the seat base foam  72 . Additional hog rings  70  may also be located along the side edges as shown to create deep styling pleats on the sides of the cushion as well. 
         [0061]      FIGS. 5 and 6  show additional embodiments of the invention with backrests.  FIG. 5  shows a single longitudinal deep styling pleat  80  in the backrest  82  that allows for air flow from the air inlet  84  to the air outlet  86  through the tubular spacer material  30 .  FIG. 6  shows a multiple styling pleats  80  in the backrest  82  which allows for air flow from the air inlet  84  to the air outlet  86  through the tubular spacer material  30 .  FIG. 6  also illustrates an embodiment with multiple deep pleats  62  in the seatrest  66 . Thermal efficiency between the user and the seat  60  or cushion  10  is improved or maintained by creating deep pleats without the need for excessive padding over the tubular spacer material  30 . 
         [0062]      FIG. 7  shows an embodiment for a convective seat or cushion with a lateral deep styling pleat  90 , which cuts across the seat cushion, effectively cutting off longitudinal internal air flow through the tubular spacer material layers in the seat and/or backrest  82  as shown in  FIG. 7  with arrows indicating air flow. 
         [0063]      FIG. 8  shows an embodiment of the invention with a series panel flow structure  92  where the deep lateral styling pleats  90  define two panels as shown in  FIG. 8  but other quantities of lateral pleats  92  with more than two panels are within the scope of the invention. Air from a heat pump such as a Stirling or Peltier system is delivered to backrest air inlet  92   a , where the air or a portion of the air that does not permeate through to the user travels up to the top of the panel through the tubular spacer material  30  and then out the back side into the U shaped duct  92   b , where the air enters the upper backrest panel as shown in  FIG. 8 . This air then flows internally up through the upper panel also containing tubular spacer material  30  to the top of the panel, where the air can exit the back of the seat  60 . 
         [0064]      FIG. 9  shows one embodiment of the invention with a parallel panel flow structure  94 . In this embodiment, air is blown into a manifold  94   a  that has a number of air outlets equal to the number of air flow panels. Air is blown simultaneously into the lower inlets of the panels, flows up through the panels, and then vents from the upper outlets  94   b  and  94   c  of the panels. For further embodiments of the invention, longitudinal air flow is enabled through adjacent panels when separated by deep styling pleats and the invention is not limited to the particular arrangements or number of panels, inlets and outlets shown in the Figures. 
         [0065]    Other embodiments of the invention include seat rests that can be configured in the same manner for lateral and longitudinal deep pleats. An advantage of the parallel arrangement is that the air temperature change is substantially the same in all of the panels, whereas in the series arrangement, the temperature change will diminish as the air flows from one panel to the next because heat is absorbed from the user in cooling mode and is transferred to the user in heating mode. 
         [0066]      FIG. 11  shows a side elevation of a series type lateral pleat air panel arrangement with a seat headrest  100  included into the top air panel. The present invention includes a parallel arrangement with three or more paths, including two or more lateral pleats and panels in the seat or backrest with an additional parallel panel for the headrest. The above embodiments for pleated seats can also be used with portable cushions by the use of thinner base foam layers in the cushion. 
         [0067]      FIGS. 12-14  show an improved Stirling cycle free-piston device  110  used in one or more embodiments of the invention. The device  110  includes a housing  112  enclosing a sealed chamber  114  that is filed with a gas within which the moving parts are located. The piston  116  is resiliently supported at one end by piston spring  118  for reciprocating movement of the piston  116  toward and away from the orifice  120 . The piston spring  118  may be of the helical coil type or of the leaf type and additionally, a lever connected to a torsion bar spring can also be used. 
         [0068]    As shown in  FIG. 12 , the magnet  130  and the coil  132  surround the piston  116  for driving the piston  116  on an electric supply from leads  134  and  136 . A displacer  138  is mounted on the opposite side of the orifice  120  that is resiliently mounted by a displacer spring  140  for gas pressure induced movement of the displacer  138  toward and away from the orifice  120 . The operation of the Stirling device produces a temperature reduction at the end  142  for cooling air that is delivered to the convective cushion  10  of the invention. 
         [0069]    As shown in detail in  FIGS. 13 and 14 , the cylinder  150  that surrounds the piston  116  includes a magnetic bearing permanent magnet  152  that is sandwiched between pole pieces  154  and  156 . The pole pieces  152  and  154  focus and direct the magnetic flux and field into the magnetic piston ring  158  embedded in the piston  116  as shown in  FIG. 13 . Since the piston  116  is supported at one end, the function of the magnetic bearing is to levitate, or suspend approximately half the total weight of the piston at the cylinder center line and maintain it there during reciprocation. 
         [0070]    In one or more embodiments, the piston  116  is made of a lightweight material other than that used for the magnetic ring and known to persons skilled in the art in order to minimize the magnetic flux, and hence bearing size, required to levitate and maintain the piston  116  and magnetic piston ring  158  on center within the annular structure of the magnetic bearing assembly and the cylinder  150  during reciprocation. The present invention includes the use of such lightweight materials. The piston  116  moves essentially in pure reciprocating motion, with little if any angular moment, which is ideal for a magnetic bearing, particularly of the passive type, as described here, and does not require auxiliary control coils or an active feedback controller to maintain bearing and piston concentricity. 
         [0071]    In an embodiment of the invention, a surface coating or treatment resulting in a very low coefficient of friction is used. For example, in the event that the Stirling device  110  is subjected to a sharp bump or high acceleration force and the piston is momentarily displaced within the magnetic bearing and the cylinder bore, low friction surfaces will minimize undesirable wear during a “hard landing” of the piston. 
         [0072]    In one or more embodiments, a ferrofluid  160  is placed in the magnetic circuit gap  162  between the stator pole  130  and piston driver coil  132  as shown in  FIG. 12 . In one or more additional embodiments, ferrofluid  160  is placed in the gap  164  between the magnetic piston ring  158  (and piston  116 ) and the cylinder  150  with the magnetic bearing permanent magnet  152  and pole pieces  154  and  156  and as shown in  FIGS. 13 and 14 . 
         [0073]    Ferrofluid is a liquid well known to persons skilled in the art that contains ferromagnetic particles in suspension so that the fluid itself acquires magnetic properties and behaves as though it is magnetic. The magnetic field of the stator magnet holds the Ferrofluid in place, while allowing the Ferrofluid to exhibit low viscosity and shear strength for low pumping losses due to the reciprocating motion of the piston driver coil. The Ferrofluid  160  increases the magnetic permeability of the air gap and increases magnetic field strength and efficiency. Another advantage of the Ferrofluid in the air gap is that heat generated in the piston driver coil is more efficiently conducted across the Ferrofluid to the stator pole and then outward to the ambient environment than it is with a gap of helium separating the piston driver coil from the stator pole. This helps to reduce temperature rise in the piston drive coil, which reduces electrical resistance changes as a function of temperature and makes for increased coil insulation life and greater reliability. 
         [0074]      FIG. 15  is a schematic flow chart of one embodiment of the invention to further enhance the performance and convenience of the seat convective cushion  10  used in a vehicle. This embodiment allows the driver, by use of a telecommunications device, such as a telephone, mobile telephone, pager or cellular phone/text messaging type communication system, to activate and, if desired, to select cooling or heating mode from blocks away in order to have the seat(s) cool down or warm up in advance, according to the weather and the preferences of the user(s). In one or more embodiments, a driver of the vehicle controls the cooling and heating of the convective cushion from a much greater distance from the vehicle than conventional “Keyless Entry” systems, which generally only work within a 25 foot radius of the vehicle, and often do not work well from angles approaching the vehicle from behind and to the side. 
         [0075]    In further embodiments, the invention allows a user to activate and control a Variable Temperature Steering Wheel, (“VTSW”), which is the subject of the inventor&#39;s U.S. Pat. No. 5,850,7641. In additional embodiments, the VTSW may be energized simultaneously with the vehicle seat using the present invention, in order to provide a steering wheel grip surface temperature that corresponds with the seat mode. 
         [0076]    For example, in warm weather, especially with bright sunlight impinging upon the interior surfaces of a vehicle, both the steering wheel grip surface and seat surfaces may become relatively very hot. It would then be desirable to cool these surfaces down to a pleasant temperature, preferably before entering the vehicle, to avoid heat stress. 
         [0077]    In embodiments of the invention, both the steering wheel and the seat can be left in cooling mode while driving in order to maintain vehicle occupant thermal comfort while using little, if any, conventional space air conditioning. This saves on fuel and reduces emissions and improves vehicle performance, as vehicle air conditioning systems typically require approximately 3-5+ horsepower, and the single convective cushion+VTSW combination requires not more than approximately 80 watts total for the Stirling Cycle type convective cushion with VTSW, and approximately 140-160 watts for the Peltier thermoelectric convective cushion with VTSW. Each additional convective cushion requires approximately 20 watts for the Stirling cycle device and approximately 80-100 watts for the Peltier thermoelectric device. 
         [0078]      FIG. 16  shows embodiments of an improved heating and cooling source device  170  with an active cooling mode re-heater  172  that regulates the relative humidity of the heat pump output air to the convective cushion  10  (arrows show air flow to a cushion) by raising the temperature of cooling mode conditioned air back to, or above, the dew point. In one embodiment shown in  FIG. 16 , the device  170  includes a main heat exchanger  171  and an auxiliary heat exchanger  173  and positive temperature coefficient (PTC) heating element  175 . 
         [0079]    In the embodiments shown schematically in  FIG. 16 , the device  170  includes a hygrometer  174  to measure relative humidity to provide control input to a controller for controlled operation of the re-heater  172 . In further embodiments, an ambient and/or conditioned air temperature sensor  176  is provided, which may be integral with the hygrometer or separate, connected to the master controller in order to provide additional control input for the control operation of the device  170  and re-heater  172 . 
         [0080]    Cooling air that contains water in vapor form to below the dew point precipitates a percentage of that water vapor as condensate. The amount of condensate depends on how far below the dew point the air is cooled. After cooling down to the dew point, or sub-cooling below the dew point, the air can be said to be saturated with vapor, or at 100% relative humidity, because it is holding all of the water that is theoretically soluble in that volume of air, as vapor, at that temperature and barometric pressure. 
         [0081]    The greater the drop in temperature for a given starting water vapor content, or relative humidity, the more condensate will be precipitated out of the air when that air is cooled. The greater the subsequent rise in temperature, (re-heat), the lower the relative humidity of that air will be because some of the water that was originally entrained in the air as water vapor has been removed as condensate, and as the temperature of that air rises it&#39;s capacity for holding water vapor increases again. However, since some of the water vapor that was originally entrained in that air has been precipitated out as condensate, the relative humidity of that air is now lower. 
         [0082]    One procedure is to first drop the conditioned air temperature enough, if the starting relative humidity is higher than desired, to get rid of some of the water vapor, then raise it enough to reduce its relative humidity, (relative humidity is simply the amount of water vapor contained in a given unit volume of air divided by the theoretical maximum amount of water vapor that can be contained in that volume of air at that given temperature and barometric pressure), without heating it up beyond the ideal or desired comfort temperature. This process is desired to provide true air conditioning, wherein the relative humidity of the environment is controlled in addition to the temperature. 
         [0083]    In one or more operating embodiments of the invention, a basic operational logic includes the following: 
         [0084]    1. If the hygrometer, (relative humidity gauge or sensor), senses relative humidity below 50%, for example, (or any other desired relative humidity), at any output air temperature, the re-heater is not energized. 
         [0085]    2. The re-heater is not energized in heating mode, unless ambient temperature is so low that it is necessary or desirable. 
         [0086]    3. If re-heat is necessary in either cooling mode or heating mode, the controller energizes the re-heater on a curve until the desired relative humidity is reached for a given selected air temperature, or until the selected temperature is maintained at a predetermined relative humidity. 
         [0087]    In further embodiments, a condensate trap (not shown) may be provided, however it is in one or more embodiments simply a small volume container with a small aperture that allows condensation produced in the main heat exchanger to drain out without allowing ambient air to leak into the cooling mode air stream. This can be accomplished in one or more embodiments by using a drain hole of approximately 0.10-0.20″ diameter plugged with a short length of wicking material (not shown) that blocks air flow while wicking liquid into the condensate trap chamber. The wick can also be extended in length and extended to reach to surface of the auxiliary heat exchanger in order to provide some evaporative cooling to the auxiliary heat exchanger, reducing its temperature and thereby increasing the coefficient of performance (“COP”) of the Stirling heat pump device by reducing the overall temperature change between the cold and hot sides. 
         [0088]    In additional embodiments of the invention, the re-heater  172  is configured to provide heated air for a heating mode that delivers heated air to the convective cushion  10  in addition to re-heat in a cooling mode as described above. 
         [0089]      FIG. 17  illustrates another embodiment of an improved free piston Stirling cycle heat pump device  170  wherein the auxiliary fan  180  is ducted to provide heated air to the reheater  172  to control the relative humidity of the air to be delivered to a convective cushion  10  (outlet arrows in  FIG. 17  show air flow to a cushion). 
         [0090]    In cooling mode, the Stirling Cycle heat pump cools air that is drawn through the main heat exchanger  171 , (main heat exchanger  171  as also shown in  FIG. 16 ). This cooled air is also blown through the passive cooling mode re-heater central heat exchanger on its way to the cushion. Simultaneously, the auxiliary fan  180  draws ambient air, via the re-heater air duct  182 , in the direction of the arrows shown in  FIG. 17  through duct  182 , through the annular passive re-heater heat exchanger fins. Thus, heat from ambient air is transferred to the cooled air raising the temperature of the cooled air and lowering the relative humidity of the cooled air, while simultaneously lowering the temperature of the ambient air that is then drawn through the auxiliary heat exchanger. 
         [0091]    In addition to lowering the relative humidity of the cushion air, other functions that may be provided include: 
         [0092]    1. The thermal transfer efficiency of heat from the auxiliary heat exchanger  173  to the ambient air is increased because reducing the temperature of the ambient air increases the temperature change between the auxiliary heat exchanger and the ambient air. 
         [0093]    2. Because of increased thermal transfer efficiency, and a lower auxiliary heat exchanger temperature, the total heat pump temperature change from hot side to cold side is reduced, increasing the COP of the Stirling heat pump device, which increases the energy efficiency of the Stirling Cycle heat pump device. In one or more embodiments, a positive temperature coefficient (“PTC”) device  175  and heat exchanger  171  shown in  FIG. 17  for heating mode can also be eliminated by attaching positive temperature coefficient elements  175  to the passive cooling mode reheater and energizing these PTC elements  175  when heating mode is desired. The auxiliary fan  180  is not energized during heating mode, so there is no air flow through the outer section of the passive reheater to reduce its efficiency in heating mode. 
         [0094]      FIGS. 18 and 19  illustrate another embodiment of the invention that can be used by more than one sleeper or sleepers simultaneously. As shown in  FIG. 18 , the plenum  12  includes a divider  190  that divides the plenum into sections, which can be two sections as shown in  FIG. 18  or more than two sections depending on the needs of the user or users. Each of the sections can have a separate inlet for delivering an air flow to the section and as shown in  FIG. 18 , a first air inlet nozzle  192  and second inlet nozzle  194  are provided in the embodiment with two sections. In further embodiments, each of the sections includes an outlet vent shown as air outlet vent  196  and air outlet vent  198  in the embodiment illustrated in  FIG. 18  to allow air flow out of the sections. 
         [0095]    The divider  190  is relatively impermeable to air and extends from the top surface  14  to the bottom surface  18  as shown in  FIG. 19  to prevent substantial lateral mingling of separate air streams supplied by a heat pump, which may be a thermoelectric heat pump with two separate cooled or heated air outputs or a Stirling Cycle heat pump with two separate cooled or heated air outputs. These heat pumps with two air outputs are not shown in  FIG. 18  because they are well known to persons skilled in the art and are essentially single output devices doubled up to create two independently adjustable heat pumps. A purpose of the dual air flow structure and system is to allow the sleepers to have different temperature settings. 
         [0096]    In embodiments of the invention, the divider  190  substantially prevents lateral mixing or mingling of the different air flows, such as from air inlet nozzle  192  and second inlet nozzle  194  as shown in  FIG. 18 . There is potential for some lateral air mixing between that portion of the air in the air flow structure that percolates up through the bedding top, however most of the air in the tubular spacer material  30  flows through the tubular spacer material  30  and vents out of the outlet vents shown as air outlet vent  196  and air outlet vent  198  in  FIG. 18  opposite the air inlets. This means that preventing lateral mixing within the tubular spacer material  30  is an effective way to provide an essentially independent air temperature within, and hence, essentially independent cooling and heating effects on the sections of the convective cushion  10 . In one or more embodiments, an extra layer  24  is provided as shown in  FIG. 18  and in  FIG. 19  which can be placed over a portion of the top surface  14  to provide temperature control for the space adjacent to one or more of the inlet nozzles  192  and  194  by limiting air flow through the top surface  14  in the area of the extra layer  24 . 
         [0097]      FIG. 20  illustrates a further embodiment of the invention in a perspective view of a solution to unraveling of filaments on the ends of cut pieces of the tubular spacer material  30 . Such a solution is applicable to the convective cushion  10  such as described and shown in  FIG. 1  and in  FIG. 18 . Prior to cutting the tubular spacer material  30  to a desired length, with length being along the longitudinal direction or length of the tubes, film  200 , such as a flexible plastic film including SARAN Wrap or tape, is affixed to the cut line or end being cut either with adhesive that has already been applied to the film  200  or with spray or brushed adhesive. 
         [0098]    After the adhesive has cured, the tubular spacer material  30  is cut down the middle of the tape or film leaving a margin of film  200  on each side of the cut line  202  as shown in  FIG. 20 . This allows the film  200  to be adhered to the fibers of the tubular spacer material  30  before cutting and remains adhered after cutting which keeps the fibers or filaments from unraveling. 
         [0099]      FIG. 21  shows in a schematic illustration an embodiment of an improved Peltier thermoelectric heat pump  210  for use with the present invention. In this embodiment, an auxiliary blower  212  draws air through an auxiliary heat exchanger  214  that has fins in both an outer air stream and an inner air stream. In the cooling mode for this embodiment, the main blower  216  draws, or blows, ambient air through the main heat exchanger  218 , cooling the air below ambient temperature. The main blower  216  then blows that cooled air through a heat exchanger that can include inner fins and outer fins. Meanwhile, the auxiliary blower  212  draws air in an opposite direction, pulling ambient air that has been cooled below ambient in the re-heater heat exchanger  220  across the auxiliary heat exchanger  214 . The thermoelectric device  215  is shown in  FIG. 21 .  FIG. 21   a  is an end view of the improved Peltier thermoelectric heat pump  210  shown in  FIG. 21  and illustrates an end view of the reheater heat exchanger  220 . 
         [0100]    The cooled air results in a lower auxiliary heat exchanger temperature, which lowers the overall temperature difference between the cold side and the hot side of the Peltier device, increasing its coefficient of performance and energy efficiency. The relative humidity of the cooled air delivered to the convective cushion (as shown in arrow  222 ) is thereby reduced. 
         [0101]    A condensate wick  224  is shown communicating between the main heat exchanger  218  and the auxiliary heat exchanger  214 . Condensation produced in the main heat exchanger  218  in cooling mode is drawn to the auxiliary heat exchanger  214  by the wick  224 , without allowing the two air streams to co-mingle, providing whatever condensate is available to the auxiliary heat exchanger  214 . The condensation evaporates on the relatively warm auxiliary heat exchanger producing an additional cooling effect which increases the COP of the thermoelectric device  210  and improves its energy efficiency further beyond what is provided by the counter-regenerative auxiliary air cooling system. 
         [0102]    In further embodiments, if a thermoelectric device has sufficient capability, such as, for example, that described in the inventor&#39;s U.S. Pat. No. 6,855,880 entitled Modular Thermoelectric Couple and Stack, it is useful to control main blower air relative humidity by using the active reheater to raise cooling air temperature and thereby reduce its relative humidity if desired. 
         [0103]      FIG. 22  is a schematic illustration of another embodiment of an improved Peltier thermoelectric heat pump  210  for use with the present invention in a heating mode. In this embodiment, the re-heat heat exchanger  220  becomes regenerative in this mode because it is a form of bottom cycling, in which heat energy is taken from a low point in the cycle to a higher point in the cycle to improve efficiency. By pre-heating auxiliary air, the cold side runs at a higher temperature in heating mode. 
         [0104]    Since the main exchanger  218  is hot in heating mode, the warmer the auxiliary heat exchanger  220  is, the lower the overall temperature change, hence the higher the COP, or energy efficiency of the Peltier thermoelectric heat pump. In one embodiment, the device  210  is designed with enough capacity to produce the desired net heating mode air temperature even with a bit of cooling provided by the regenerator. 
         [0105]      FIG. 23  illustrates one or more embodiments of the invention for cooling and heating multiple surfaces, such as seating surface and a sleeping surface, with the same air cooling or heating source. The first convective cushion  300  includes a first plenum  302  having a generally air permeable top surface  304  that is secured around a perimeter  306  to a bottom surface  308 . The bottom surface  308  is in one or more embodiments generally impermeable to air and can be placed on a mattress  310  as shown in  FIG. 23  and  FIG. 24  to make the bottom surface  308  generally impermeable. A fitted sheet  318  may be used to secure the first plenum  302  to the mattress  310  and an elastic band  320  can also be used to secure the first plenum  302  and the mattress  310  together. 
         [0106]    The first plenum  302  includes tubular spacer material  312  as an air flow structure which includes the use of tubular spacer fabric, air flow structures such as Muller Textile&#39;s 3 Mesh or Strahle and Hess&#39; assembled woven fabric and other air flow structures known to persons skilled in the art as previously described herein. As shown in  FIG. 23 , air enters the first plenum  302  mattress pad through the air inlet nozzle  314 , which may be removable, and fans out within the tubular spacer material  312 , with some of the air permeating up through the top surface  304  as the air flows toward the air outlet vents  316 . The tubular space material  312  is arranged so that the longitudinal axes of the tubular spacer material  312  are all aligned to allow substantially uninterrupted flow of air from the air inlet nozzle  314  to the air outlet vents  316  at an opposite end of the first plenum  302 . 
         [0107]    The second convective cushion  330  includes a second plenum  332  that in one or more embodiments is formed to fit within a seat or portable seat cushion  334  as shown in  FIG. 23 . The second plenum  332  includes tubular spacer material  312  as described above for the first plenum  302 . Air enters the second plenum  332  through the air inlet  336  and fans out within the tubular spacer material  312 , with some of the air permeating through the second plenum as the air flows toward the outlet vents  338 . The power unit  340  includes a blower and a heat pump  341  that delivers either heated or cooled air through the first duct or conduit  342  to the air inlet nozzle  314  and to the first plenum  302  while also delivering the same heated or cooled air through the second duct or conduit  344  to the air inlet  336  and to the second plenum  332 . The heat pump  341  can be a thermoelectric heat pump, a Stirling cycle heat pump or other type of heat pump that supplies cooled and/or heated air. 
         [0108]    As shown in  FIG. 23 , the first valve  346  can be placed adjacent to or within the first duct or conduit  342  to control the flow of air to the first plenum  302 . A second valve  348  can be placed adjacent to or within the second duct or conduit  344  to control the flow of air from the power unit  340  to the second plenum  332 . The first valve  346  and the second valve  348  can be adjusted to control the cooling and/or heating of both the first convective cushion  300  and the second convective cushion  330  either individually or simultaneously. The valves  346  and  348  enable the air flow from the power unit  340  to be controlled so that more or less of the temperature modified air can be delivered to one, or both, of the first convective cushion  300  and the second convective cushion  330  which is a cost effective method of enhancing the controllability of convective cooling and/or heating. If most or all of the temperature modified air is directed to the first convective cushion, then the cooling or heating of this cushion will be more pronounced. If most or all of the temperature modified air is directed to the second convective cushion, then the cooling or heating of this cushion will be more pronounced. The valves  346  and  348  can be adjusted manually, by electronic power controls, by a remote control operation or other methods of control known to persons skilled in the art and these are included within the scope of the present invention. 
         [0109]    While the present invention has been described with regards to particular embodiments, it is recognized that additional variations of the present invention may be devised without departing from the inventive concepts in the claims and the invention includes the full breadth and scope of the claims including all equivalents.