JP2001204588A - Variable temperature cushion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cushion for receiving selectively variable temperature air which can withstand a user sitting, leaning or lying thereupon without significantly closing off the ready transfer of the variable temperature air throughout it. SOLUTION: This device includes: a plurality of individual hollow-center tubes 34 arranged in a single plane to form a pad with the longitudinal axes of the tubes being arranged in mutually parallel relation, the tubes having sidewalls constructed of synthetic plastic fibers 36 woven to maintain an open- weave construction with the fibers at fiber crossover points not sliding against one another; open-weave synthetic plastic fiber layers the fibers of which are open-weaved so as not to slide against one another, for securing the pad tubes in fixed predetermined spaced apart relation; an impermeable layer 14 enclosing the sides and the bottom of the pad of the tubes; and an air and vapor impermeable foam layer 19 covering the pad and connected to the sides of the impermeable layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to a cushion for use as a mattress or seat and backrest, which provides a selectively variable temperature and outer surface of the device, reducing the temperature of a cushion operating in a Stirling cycle. To a device including a heat pump.

[0002]

BACKGROUND OF THE INVENTION Cushions, such as, for example, motor vehicle seats or backrests, are preferably capable of being selectively cooled or heated to provide comfort when someone sits or rests on the cushion. There is a situation. In cold environments, especially in winter, it is desirable to sit in the seat before the automatic operation of the automatic heating device or to heat the seat cushion in a relatively short time to warm up the leaning passengers, but this heating device is usually For the operation to be performed sufficiently, it is necessary that the refrigerant of the engine has a sufficiently high temperature. In the warmer months, vehicles with conventional air conditioning systems that direct cooling air directly in front of passengers and into the interior of the vehicle may have undesirably high temperatures and high humidity where air directly contacts and comes into contact with seat and back cushions. This would make the occupants of the car even more uncomfortable. In both warm and cold season situations, the warmth or coldness of the cushion itself increases the level of individual comfort.

[0003] Certain more effective chemicals (eg Freon) are considered harmful to the environment.
n)) is excluded as a material for air conditioners. At this time, all other replacement materials known for this purpose do not have the same high level of efficiency and, in fact, are inferior to freon. Also, future vehicles will basically need to operate with less power to conserve fuel and reduce harmful products, which will gradually reduce the proportion of power available by air conditioners or heating devices.

In US Pat. No. 5,002,336 to Steve Feher, there is shown a seat and backrest to provide the cooling or heating desired when the heat pump used for this purpose is a thermoelectric unit, which is a conventional thermoelectric unit. It achieves the desired function with much lower energy requirements than if the entire interior of the vehicle were regulated by air conditioning technology. However, even when considering other known prior art,
It is believed that there is room for improvement in increasing the efficiency of the overall operation.

In US Pat. No. 5,002,336, the seat and back structure includes an air chamber for receiving conditioned air, the structure of the air chamber being a metal wire spring coil having side wall openings or a relatively rigid structure. Formed from a plastic tube. To make it work properly,
The seat structure must be such that the conditioned air does not significantly block the flow of air with the occupant's sitting or leaning weight and can easily pass through the air chamber.

[0006] In addition, automotive seat manufacturers have found that the inner support (eg, a spring coil) must create a visible seat surface aesthetic, and it is not desirable to disrupt the decorative aesthetic of the seat. Be considered. In this regard, it has been found that simply increasing the thickness of a comfortable layer disposed on a wire spring or rigid plastic tube is inconsistent with its intended purpose. This is because it reduces heat transfer and overall operating efficiency.

[0007]

In describing the various aspects of the present invention, the term "cushion" as used in this specification refers to the term "cushion", the temperature of which is adjusted by the device described above and used in conjunction with the device described above. Seat "and" Backrest "
It refers to products with "mattress pads". "Sheet"
These terms are used when referring to either "backrest" or "mattress pad".

Accordingly, it is a primary object of the present invention to provide a variable temperature cushion that includes an inner chamber for selectively receiving variable temperature air, such that the chamber does not close during use. It is not uncomfortable or forms a contact, does not provide an external signature of the chamber formation means, and does not require a relatively thick outer comfort layer that produces extracts that are prohibited at the level of heat transfer.

As a first embodiment of the cushion, a strongly flexible tube is formed to form a plurality of loosely woven tubes held between a pair of similarly woven sheaths of the same material. A filament made of synthetic resin having a certain characteristic is used. Thus, a flexible, porous, air permeable pad is provided that resists occupants from hanging on the pad and closing the tubular chamber by sitting or sleeping. Having sufficient rigidity, in this way conditioned air passes along the tubular portion,
It can pass outward through the woven wall and adjust the area around the air chamber formed in the cushion. The tubes are made from woven plastic filaments, which are not fixed at intersections with each other,
Instead, the filaments slide freely with respect to each other, resulting in a better sitting comfort for the user.

[0010] The cushion pad provided has an air impervious bottom and side walls, while a loosely woven fabric upper cover provides air permeability. To add additional flexibility and comfort, a layer of intermediate density and low open cell variability foam is inserted between the fabric cover and the cushion chamber structure described in the immediately preceding paragraph. You. The foam layer must be structured to provide good air and vapor permeability.

A conditioned air inlet duct is mounted on the trailing edge of the cushion and conducts air to the cushion along a predetermined number of separated grooves. When conditioned air is supplied to a pair of cushions (e.g., seat and back), the duct directs the flow of air in separate grooves to each cushion.

[0012] The air permeable woven tubular cushion structure can be dimensioned to act as a mattress or pad arranged in a conventional mattress of the same dimensions.

[0013] A heat pump, preferably including a Stirling cycle conditioner, is used to selectively reduce the temperature of the compressed air that is moved along the flexible hose to the cushion inlet duct. In practice, Stirling cycle conditioners are 5 to 6 times more efficient than thermoelectric coolers and are less expensive to manufacture. Also, in terms of the amount of heat delivered, a Stirling pump is smaller than the corresponding thermoelectric unit and is about the same in weight per unit heat delivered.

Preferably, the Stirling heat pump is a sealed free piston unit that includes a pair of helical coil springs coaxial with the balance mass to reduce unwanted vibrations.

A ceramic or resistive PTC heater mounted on the conditioner warms the air during a heating mode in which the cooling portion of the conditioner is kept inactive. The heater has a pin or post structure heat exchanger that further promotes heat transfer to and from the atmosphere.

The collected condensate to the cooling conditioner can fall down to the receiving trap following the weight path and then to the felt pad along the conduit. Electric heater
The condensate evaporates from the felt to ambient air.

[0017]

DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings, and in particular to FIG. 1, the present invention is shown and described in connection with a pair of cushions 10 and 12. FIG. This pair of cushions 10 and 12
Is manufactured in accordance with the principles of the present invention and is intended to be used particularly in motor vehicles.
Includes a seat, and the cushion 12 is a backrest. The structure of the two cushions 10 and 12 is identical, so only the structure of the cushion 10 will be described in detail.

Referring to FIG. 2, the cushion 10 includes a cushion bottom, two side walls and an outer underlayer 14 covering the backside, these sides being made of a number of different materials and having the main physical properties. Are impermeable to the passage of air and moisture. In particular, the inner portion 16 described later
It has the necessary stiffness to provide comfort and to prevent closing all or any part of the air chamber during use, while creating an air chamber that receives the temperature regulated air.

A relatively thin foam layer 19 of low to medium density and open structure is disposed over the upper surface of the chamber 16 to allow good air and vapor permeability. This foam layer provides comfort to the user. A woven textile cover or layer 20 is arranged over the foam layer 19, and the cover or layer 2
0 is a fabric that is sufficiently open so that air can easily pass between them.

From the cushion structure described above, the side, rear and bottom surfaces of the cushion are impermeable to air,
The upper and leading edge surfaces facing the user's foot are highly permeable to both air and vapor. Thus, in fact, the seat cushion forms an air chamber, which is
Compressed air is received in the manner described above, and this air exits through a permeable portion of the cushion that is not covered by the user's body to optionally heat or cool.

For further details of the cushion structure, reference is made to FIG. As described above, the cushion 10
Includes an impermeable layer 14 that covers the bottom and sides of the cushion except the front. Similarly, the outermost upper fabric layer 20
There is a foam pad 19 below. Foam pad 1
The interior of the air chamber between 9 and the impermeable layer 14 is filled with a tubular pad 32 comprising a plurality of tubular members 34, which extend parallel to each other and parallel to the foam pad 19. And the axial direction of each of the tubular members 34 is
It extends from the rear surface to the front side for illustrative purposes.
More specifically, the tubular members are woven from elastic plastic filaments 36 and arranged in edge contact relation to form a substantially flat sheet of tube. The individual tubular members are
Secured together by first and second open fabric layers 38 and 40, the first and second open fabric layers 38 and 40 are made from filament 36 and disposed on opposite sides of the tubular member plane, Woven with each other. In this way, there is a single structure in which air can move transversely through both walls of the open fabric sheet as well as the tubular member on each side for only a moderate back pressure, and the air flow is controlled by the tubular member, Limited by very low back pressure as it moves axially through itself. In use, the aforementioned tubular pad 32 not only provides a more flexible and relatively soft layer than the individual seats, but also prevents the tubular passage from being closed during use. Furthermore, the woven filament structure is not visible in the top layer 20 to give the appearance of the coil below. An important aspect of the layers 38 and 40 interconnected with the woven structure of the tube is that the filaments are not sealed to each other at tolerance points and can move when subjected to pressure (FIG. 11), a feature of this. It is considered to add a soft touch during use of the cushion. On the other hand, the woven structure and the natural physical characteristics of the fibers are such that when under pressure, the filaments do not move to a very large extent during use, instead of relatively moving.

A suitable material for making the tubular pad 32 is manufactured by Tetko, Inc. of New York and sold under the trade name "Tub."
lar Fabric ". FIG. 3 shows a single heat pump 44 from seat and back cushion 10.
1 and 2 show an air inlet duct 42 for use in introducing and distributing temperature conditioned air, the air inlet duct 42 being described in more detail below. With reference to the plan view, the ducts have four points to distribute to both the seat and the backrest at corresponding different points measured over the width of each cushion.
It can be seen that it is divided into two separate grooves 46, 48, 49 and 50. Further, the duct has a separation wall 52,
The separation wall 52 separates the distribution of the plurality of grooves of the backrest from the plurality of grooves distributed to the seat cushion (see FIG. 1).

More specifically, a flexible plurality of channel conduits 53
Has one end 54 interconnected to a heat pump 44 that receives a supply of conditioned air, and the other end having a co-fitting 55 removably connected to the duct 42. In this manner, the duct 42 has each of the channels with an individual conditioned air supply.

The conditioned air inlet duct 42 is positioned as follows with respect to the cushion. That is, an outer inlet fitting 56 to which the flexible conduit fitting 55 for introducing conditioned air is connected is located adjacent to the side of the cushion. This allows interconnection to the heat pump via a flexible hose, which does not interfere with the position of the seat and proves to be very convenient during use. Most of today's cars have a strip of cloth sewn into the curved line between the backrest and the seat rest, and the symmetrical location of the air inlet duct fittings in this case reduces the possibility of interference with the installation Reduce.

In the overall operation of the cushion and related devices described in this regard, the regulated airflow is compressed along the flexible conduit hose from the heat pump 44 to the air inlet duct 42 where the seat rest and Separated into two approximately equal parts by a wall 52 for transmission or distribution to the backrest cushion. Finally, the conditioned air is divided into four substantially equal sections for each of the cushions, distributed forward along the cushion in the case of a seat and upwardly in the case of a backrest. In addition to heating or cooling the surface of the cushioning material facing the user, the structure described above allows the conditioned air to easily and relatively uniformly transmit via convection through the cushion, A very small airflow can be sent to the occupant using the cushion.

Normally, conditioned air is used to produce the desired cushion, but with a correspondingly higher efficiency compared to devices that rely on relatively high Δt operation and thermoelectric elements (eg, Peltier elements). Another heat pump that has been found to be most advantageous for this purpose in terms of operation is a Stirling cycle pump with a free piston located in a sealed chamber (see FIG. 5). In this overall aspect, the Stirling cycle heat pump 44 has a “cold” end 58 while discharging air containing waste heat at a second or “hot” end 60. It can be seen that the cold end 58 of the heat pump is surrounded by an air chamber 61 which has a main heat exchanger fin 62 fixed to the outermost end face of the cold end 58 in good heat conduction relation. Siege. The main blower 64 consisting of a fan driven by an electric motor is
And draws air from heat exchanger fins 62, which are cooled by a heat pump and pressurize the air sent to the cushion via flexible hose 66. At the same time, an auxiliary fan (not shown) is located in the other chamber relative to the "hot end" 60 of the heat pump. The purpose of the auxiliary fan is to remove the waste heat accumulated at the hot end and discharge it to the outside of the heat pump (see arrows in FIG. 4).

Although the use of the heat pump has been described in the cooling mode, it is desirable to provide a means for heating the air when it is cold and cold. To this end, the heat from the hot end of the Stirling engine can be sent to the cushion instead of the cooler air, which is entirely satisfactory with the need for this device to be large and expensive. Not something.
Instead of using a Stirling cycle in heating mode,
It has been found that a ceramic or resistor heater 70 of the positive temperature coefficient category is preferably located at the cold end 58 of the heat pump inside the heat exchanger air chamber 61. For use in the heating mode, a sufficient amount of current (e.g., 100 to 150 watts) is passed through the heater 70 to raise the airflow temperature to the cushion to about 110 ° F (43.3 ° C), while Then, the operation of the Stirling heat pump is stopped. Therefore, the main blower 64 receiving the heat from the heater 70 transfers the heated air along the same passage as the flexible hose 66 uses when in the cooling mode.
Pass along to the cushion.

While other heat pumps operating on the Stirling cycle principle have been found to be effective, the practical structure of the present invention was made by Sunpower, Inc., Athens, Ohio, and is marketed under the trade name M223. Excellent results can be achieved with a linear free piston heat pump driven by an electric motor.
The temperature of the air added to the cushion is 4 ℃ of the ambient temperature
And 2.5 per input watt to the Stirling pump
Watts of cooling are obtained.

FIG. 5 shows, in cross-section, the main components of a Stirling device 44 useful in practicing the present invention. This device has a housing 72, which is a gas-filled sealed chamber 7 in which the entire moving part is located.
Surround 4 The free piston 76 has an inner orifice 78
And resiliently attached to the housing by a spring 77 movably toward and away from the housing. Magnet 80 and coil 82 surround the piston to drive the piston by electrically energizing via conductors 84 and 86. Opposite the orifice 76 is a displacer 88, which is resiliently mounted by a spring 90 to allow limited gas pressure induced movement toward and away from the orifice 78.

In use, coil 82 is energized with an electrical pulse to cause reciprocation of piston 76. The compressed gas is sent to the piston 76 through the orifice 78 to move the displacer 88 to the expansion space 92.
Between the pulse drive and the next pulse drive, the piston is returned by the spring 77, and the displacer is likewise moved by the spring 9
Returned by 0. By the reciprocating motion described above,
The housing end adjacent to the expansion cavity 92 causes a temperature drop, while the opposite housing end increases in temperature.

A continuous complication is the elimination of condensate collected in the heat exchanger fins 62 of the main heat exchanger during operation during the cooling operation. Most automobile manufacturers have stated that it is not easy or desirable to drain condensate by discharging excess condensate through the car floor. This is because the drain openings can become blocked or blocked, resulting in the accumulation of unwanted condensate on the vehicle floor. In the present invention, in order to solve this problem, a condensate removing means 94 having a condensate trap 96 is provided. The condensate trap 96 includes an aluminum plate 98 on which a felt pad 100 is provided. Fixed. Various ceramic or resistive heaters 102, preferably with a positive temperature coefficient that reduce the likelihood of overheating, are located on top of the aluminum plate and interconnected with a suitable power supply (not shown). The conduit 104 connected to the heat pump and connected to the seat cushion and the backrest has a loop 106 which is a primary heat exchanger heat fin for receiving condensate dripping thereon along a gravity path. Is located under. The drain means 108 (or felt core) interconnected inside the loop or trap is routed along the gravity path to empty the condensate directly to the felt pad 100. In operation, condensate trapped by the trap and sent along the drain means to wet the felt pad is evaporated by heater 102 to return the condensate to atmosphere.

Referring to FIG. 8, the cushion 1 has an overall size sufficient for one or more occupants to sit thereon.
10 is shown. In particular, the cushion 110 comprises a tubular pad 112, an upper foam pad 11 having a permeable top layer.
4, having a non-permeable outer layer and a bottom 118, configured similarly to the cushion shown and described in detail in FIG. 2, and optionally, eliminating the entire foam pad 114.

The cushion 110 may be a separate individual mattress or, as shown in FIG.
It can also be used as a pad arranged at More specifically, in this embodiment, the cushion 11
0 is covering 122 of a woven fabric such as a fit sheet
And secured in this position by a layer 124 that is sewn or otherwise secured to the covering 122. In the area of the cushion opposite the foot of the person above it, the cushion is surrounded by a layer of material 125 which reduces the cooling effect of this area.
This cushion assembly can be elastic band, sewn or
Alternatively, it is secured on the mattress by other conventional securing means. Such cushions are considered advantageous for medical use in bedridden patients.
The conditioned air is sent from the Stirling pump to the cushion 110 via a suitable conduit in the same manner as in the previous embodiment (FIG. 8).

Referring to FIG. 12, a Stirling cycle heat pump 1 having vibration and noise delay means 132
A cross-sectional view of another configuration 30 is shown. In normal operation, a Stirling cycle heat pump with a free working piston is kept with a certain amount of vibration and noise to a minimum, and this heat pump is placed in the motor vehicle, closely adjacent to the so-called front seat . More specifically, first and second axial extensions 136 and 13 held within first and second helical springs 140 and 142, respectively.
8 is mounted in the heat pump outer housing 44 and includes extensions 136 and 13
8 is a movement path of the piston of the heat pump (not shown)
And coaxial. In operation, the oscillating motion and noise introduced by the operation of the pump piston will cause the mass portion 13
4 is attenuated by the counter inertia operation.

FIG. 13 further includes a set of pin-shaped fins 146 that serve to be operated as a heat exchanger.
This heat exchanger has been found to have particular advantages in improving operating efficiency during heating with the PTC ceramic / resistor 70. The pin-like shape is considered superior to the normally flat fin shape of conventional heat exchangers in efficiently receiving the movement of compressed air.

Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made within the scope of the appended claims.

[Brief description of the drawings]

FIG. 1 is a side view in which a part of a cushion of a temperature adaptive seat of the present invention is cut off.

FIG. 2 is an enlarged partial sectional view of a seat cushion.

FIG. 3 is a side view of a cushion and an inlet duct.

FIG. 4 is a side view showing a cross section of a part of the heat pump.

FIG. 5 is a sectional view of a free piston Stirling cycle device used in the heat pump of FIG. 4;

FIG. 6 is a perspective view of a condensate removing means used with the heat pump of FIG. 4;

FIG. 7 is a perspective view, in cross section, of a portion of a flexible conduit interconnected with a cushion entry duct.

FIG. 8 is a schematic partial cross-sectional view of another version of the cushion used as a sleeping pad.

FIG. 9 is a side view of the present invention shown with the condensate handling means of FIG. 6;

FIG. 10 is a side view of the cushion of FIG. 8 shown assembled on a mattress.

FIG. 11 is an enlarged partial sectional view of the air chamber forming means of the present invention.

FIG. 12 shows another Stirling device for use with the present invention.
It is sectional drawing of the form of a pump.

FIG. 13 is a drawing of another embodiment of a heating device used with the present invention.

Claims (20)

[Claims] (A) a center with a top surface, a bottom surface and side surfaces made of interwoven synthetic monofilament fibers forming a plurality of substantially parallel tubes arranged in parallel in a single plane; An arranged air chamber, wherein the walls of the air chamber are woven so as to open, and the compressed conditioned air received in the air chamber has a relatively low back pressure in the longitudinal direction of the tube. Along the path of the tube and along the path of high back pressure transverse to the longitudinal axis of the tube, the tube being sufficiently rigid laterally so that it does not collapse significantly during use. (B) an air and moisture impermeable layer covering the bottom and side surfaces of the air chamber; and (c) an air permeable foam sheet covering the top surface of the air chamber. A cushion having air and moisture impermeable to the air chamber. Duct means mounted to extend through the active layer; and means releasably connected to air duct means for selectively cooling or heating the compressed air stream, including a Stirling cycle heat pump to cool the compressed air stream. And a variable temperature cushion device comprising: 2. The apparatus according to claim 1, wherein said Stirling cycle heat pump is a linear free piston device driven by an electric motor. 3. The inter-woven fiber of the air chamber,
The device of claim 1, wherein the device is adhered to a major surface of the woven open mesh layer. 4. The apparatus of claim 1, further comprising means for receiving condensate from the Stirling pump and evaporating the condensate to atmosphere. 5. The means for receiving the condensate comprises a metal plate having an absorption pad on one major surface, and a heating means disposed between the metal plate and the pad. The device according to claim 4. 6. The apparatus according to claim 5, wherein said heating means is a positive temperature coefficient electric resistance heater. 7. The apparatus according to claim 6, wherein said heating means is a ceramic heater having a positive temperature coefficient. 8. The apparatus of claim 1 wherein a pair of variable temperature cushion devices are interconnected with the duct means.
An apparatus according to claim 1. 9. The apparatus according to claim 1, wherein said duct means comprises a plurality of separated air passages arranged in a fixed side-by-side relationship. 10. A chamber made of interwoven and interwoven synthetic plastic monofilament fibers forming a plurality of substantially parallel tubes arranged in parallel in a single plane. Wherein the wall of the tube is knitted open so that, in use, compressed conditioned air received in the air chamber along a relatively low back pressure passage along the length of the tube. , And can easily move along both high back pressure passages transverse to the longitudinal axis of the tube, releasing the first and second monofilaments located on opposite sides of the plane of the parallel tube. An air chamber that secures a tube with parallel woven layers; (b) an air and moisture impermeable layer covering the bottom and sides of the air chamber; and (c) the upper surface of the air chamber. Air permeable that covers and is positioned so that the lower air chamber tubes do not rise A cushion pad having a foam sheet; air duct means interconnected to the cushion pad air chamber; and air duct means for selectively cooling or heating compressed air sent to the cushion air chamber via the air duct means. And a cooling and heating means releasably connected to the apparatus. 11. A cooling and heating means for selectively cooling and heating the air flow is connected to the heat pump having a low-temperature end and a high-temperature end and to the duct means so as to surround the low-temperature end of the heat pump. Heat pump air chamber,
A main blower mounted to send air from the heat pump air chamber to the cushion air chamber through the duct means, and an electric resistance heater mounted in the heat pump air chamber, wherein the heat pump and the electric resistance heater are The apparatus of claim 10, wherein the apparatus is separately and individually activated to selectively provide a heating mode or a cooling mode. 12. The apparatus according to claim 11, wherein the heat pump is a free piston pump driven by an electric motor in a Stirling cycle. 13. A heat exchanger fin is secured to the heat pump cold end and disposed within the heat pump chamber and is absorbed outside the heat pump chamber to receive moisture condensate exiting the heat fin along a path of gravity. 12. Apparatus according to claim 11, wherein an agent felt pad is arranged and the heating means contacts the felt pad to evaporate the condensate. 14. The felt pad is mounted on a metal plate, and the heating means includes a resistive heater disposed between the metal plate and the felt pad in good thermal conductive contact with each other. The apparatus of claim 13, comprising: 15. The apparatus of claim 14, wherein the resistive heater is a positive temperature coefficient ceramic heater. 16. A drain pipe receives condensed liquid from a container, the condensed liquid dripping from a fin being received by a container having an open top and moving outside the pipe along the pipe by gravity to drop onto a felt pad. Apparatus according to claim 13, characterized in that: 17. Apparatus according to claim 10, wherein the duct means has a plurality of individual grooves along which the conditioned air is sent to the cushion chamber. 18. A cushion that selectively receives variable temperature air that can withstand a user sitting, leaning down and lying down without significantly blocking easy transmission of variable temperature air throughout. A plurality of hollow tubes centered on a single plane with the longitudinal axes arranged in a mutually parallel relationship to form A plurality of hollow-core tubes having side walls made of synthetic plastic fiber woven so that they do not slide together and maintain a woven structure; and A synthetic plastic fiber layer woven open so as not to slide against each other, and an impermeable layer surrounding the sides and bottom of the pad of the tube And an air vapor permeable foam layer that covers the pad and is connected to a side surface of the impermeable layer. 19. Means for providing cooling air including a Stirling cycle, a free-piston heat pump with a cold end during operation, pad blower means for moving air from the heat pump cold end to the pad, and the heat pump. A duct means interconnecting the cold end, and a positive temperature coefficient heating means attached to the heat pump cold end, wherein the positive temperature coefficient heating means is a pad when the Stirling cycle heat pump is operated. 19. The cushion of claim 18, operable to heat air moving to the cushion. 20. A pin-shaped heat exchanger fin is disposed immediately adjacent to said heating means, said fin contacting cold regulated air at a cold end when the Stirling cycle heat pump is operated. Claim 19
The cushion according to.