U.S. patent application number 11/348701 was filed with the patent office on 2006-08-10 for heat, cool, and ventilate system for automotive applications.
This patent application is currently assigned to L&P Property Management Company. Invention is credited to Corina Alionte, Jintao Liu, Robert J. McMillen, Iulian Mitea, Jianlin (Daniel) Zhang.
Application Number | 20060175877 11/348701 |
Document ID | / |
Family ID | 36405982 |
Filed Date | 2006-08-10 |
United States Patent
Application |
20060175877 |
Kind Code |
A1 |
Alionte; Corina ; et
al. |
August 10, 2006 |
Heat, cool, and ventilate system for automotive applications
Abstract
A ventilation, temperature regulation, and ergonomic comfort
system for a vehicle seat, comprising a cushion comprising a
ventilation layer comprising non-woven plastic fibers fused
together in such a manner as to permit airflow therethrough, the
ventilation layer having a seat surface side and a reverse side,
wherein the ventilation layer is disposed within a substantially
air-tight compartment having an access hole for air input on the
reverse side of the ventilation layer and a plurality of output
holes on the seat surface side; an adjustable ergonomic support
device, wherein the ergonomic support device is disposed on the
reverse side of the ventilation layer and moves together with the
cushion; a temperature regulation system comprising an air-moving
device operably coupled to the access hole on the reverse side of
the ventilation layer, such that the air-moving device moves
conditioned air into the ventilation layer and out through the
plurality of output holes; and a control module comprising controls
for controlling operation of the temperature regulation system and
the ergonomic support device, wherein the seat surface is
maintained at a temperature.
Inventors: |
Alionte; Corina; (Windsor,
CA) ; McMillen; Robert J.; (Tecumseh, CA) ;
Liu; Jintao; (Windsor, CA) ; Mitea; Iulian;
(Windsor, CA) ; Zhang; Jianlin (Daniel); (Windsor,
CA) |
Correspondence
Address: |
HUSCH & EPPENBERGER, LLC
190 CARONDELET PLAZA
SUITE 600
ST. LOUIS
MO
63105-3441
US
|
Assignee: |
L&P Property Management
Company
South Gate
CA
|
Family ID: |
36405982 |
Appl. No.: |
11/348701 |
Filed: |
February 7, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60650763 |
Feb 7, 2005 |
|
|
|
Current U.S.
Class: |
297/180.14 |
Current CPC
Class: |
B60N 2/5635 20130101;
B60N 2/5685 20130101; B60N 2/5692 20130101; B60N 2/5621 20130101;
B60N 2/99 20180201; B60N 2/5657 20130101; B60N 2/66 20130101; A47C
7/74 20130101 |
Class at
Publication: |
297/180.14 |
International
Class: |
A47C 7/74 20060101
A47C007/74 |
Claims
1. A ventilation, temperature regulation, and ergonomic comfort
system for a vehicle seat, comprising: a cushion comprising a
ventilation layer comprising non-woven plastic fibers fused
together in such a manner as to permit airflow therethrough, the
ventilation layer having a seat surface side and a reverse side,
wherein the ventilation layer is disposed within a substantially
air-tight compartment having an access hole for air input on the
reverse side of the ventilation layer and a plurality of output
holes on the seat surface side; an adjustable ergonomic support
device, wherein the ergonomic support device is disposed on the
reverse side of the ventilation layer and moves together with the
cushion; a temperature regulation system comprising an air-moving
device operably coupled to the access hole on the reverse side of
the ventilation layer, such that the air-moving device moves air
into the ventilation layer and out through the plurality of output
holes; and a control module comprising controls for controlling
operation of the temperature regulation system and the ergonomic
support device, wherein a seating surface of the seat is maintained
at a predetermined temperature.
2. The ventilation, temperature regulation, and ergonomic comfort
system of claim 1 wherein the seating surface is maintained at a
temperature determined by a thermistor.
3. The ventilation, temperature regulation, and ergonomic comfort
system of claim 2 wherein the temperature regulation system further
comprises an air temperature adjusting system for adjusting the
temperature of air that is moved out through the plurality of
output holes on the seat surface side of the ventilation layer.
4. The ventilation, temperature regulation, and ergonomic comfort
system of claim 3 wherein the thermistor comprises a positive
temperature coefficient thermistor-based heating device.
5. The ventilation, temperature regulation, and ergonomic comfort
system of claim 4 wherein the air temperature adjusting system
further comprises a thermoelectric device operably coupled to the
air-moving device.
6. The ventilation, temperature regulation, and ergonomic comfort
system of claim 5 wherein the temperature regulation system further
comprises a temperature sensor below a seat surface material to
sense the temperature of the seat surface material, wherein the
temperature sensor is insulated from surrounding air currents.
7. The ventilation, temperature regulation, and ergonomic comfort
system of claim 6 wherein the temperature regulation system further
comprises a proportional, integral, and derivative controller.
8. The ventilation, temperature regulation, and ergonomic comfort
system of claim 5 wherein the temperature regulation system further
comprises a positive temperature coefficient thermistor-based
heater in the air duct.
9. The ventilation, temperature regulation, and ergonomic comfort
system of claim 7 wherein the control module is disposed within the
vehicle seat.
10. The ventilation, temperature regulation, and ergonomic comfort
system of claim 5 wherein the air-moving device and the
thermoelectric device share a single pair of power leads.
11. The ventilation, temperature regulation, and ergonomic comfort
system of claim 3 wherein the ventilation layer further comprises a
second layer of non-woven plastic fibers adjacent the seat surface
side of the ventilation layer, wherein the second layer of
non-woven plastic fibers is fused together to permit airflow
therethrough but is more compressible than the ventilation
layer.
12. The ventilation, temperature regulation, and ergonomic comfort
system of claim 7 wherein the ergonomic support device is a lumbar
support.
13. The ventilation, temperature regulation, and ergonomic comfort
system of claim 12 wherein the lumbar support is a belt-style
lumbar support.
14. The ventilation, temperature regulation, and ergonomic comfort
system of claim 1 wherein the cushion further comprises a base
cushion that is disposed between the ergonomic support device and
the reverse side of the ventilation layer, the base cushion having
a hole therethrough to permit air flow into the ventilation
layer.
15. The ventilation, temperature regulation, and ergonomic comfort
system of claim 14 wherein the base cushion is divided into a
plurality of vertically-adjacent sections by at least one
horizontally-disposed channel.
16. The ventilation, temperature regulation, and ergonomic comfort
system of claim 15 wherein the ventilation layer is divided into a
plurality of vertically-adjacent sections by the at least one
horizontally-disposed channel, such that the plurality of sections
of the ventilation layer are separated from one another.
17. The ventilation, temperature regulation, and ergonomic comfort
system of claim 16 wherein the air-moving device is operably
coupled to the plurality of vertically-adjacent sections of the
ventilation layer by a manifold.
18. The ventilation, temperature regulation, and ergonomic comfort
system of claim 16 further comprising a plurality of air-moving
devices, wherein each of the plurality of vertically-adjacent
sections of the manifold has an air-moving device operably coupled
thereto.
19. The ventilation, temperature regulation, and ergonomic comfort
system of claim 15 wherein the ergonomic support device interacts
with a single section.
20. The ventilation, temperature regulation, and ergonomic comfort
system of claim 15 wherein the ventilation layer curves around the
at least one horizontally-disposed channel.
21. The ventilation, temperature regulation, and ergonomic comfort
system of claim 1 further comprising a trim layer adjacent the seat
surface side of the ventilation layer, wherein the trim material is
air-permeable.
22. The ventilation, temperature regulation, and ergonomic comfort
system of claim 1 further comprising overmolding of foam on an edge
of the ventilation layer.
23. The ventilation, temperature regulation, and ergonomic comfort
system of claim 17 further comprising overmolding of the manifold
with foam onto the cushion.
24. The ventilation, temperature regulation, and ergonomic comfort
system of claim 1 further comprising a lateral bolster, wherein the
lateral bolster comprises non-woven plastic fibers fused together
in such a manner as to permit airflow therethrough.
25. The ventilation, temperature regulation, and ergonomic comfort
system of claim 5 wherein the temperature regulation system further
comprises a positive temperature coefficient thermistor-based
heater adjacent to the heating side of the thermoelectric
device.
26. The ventilation, temperature regulation, and ergonomic comfort
system of claim 5 wherein the temperature regulation system further
comprises positive temperature coefficient thermistor to sense a
temperature of at least one of the vehicle seat and the
thermoelectric device.
27. A control system for a ventilation, temperature regulation, and
ergonomic comfort system for a vehicle seat, comprising: a control
module; a thermoelectric device comprising a thermoelectric module
and a heat sink attached to the thermoelectric module; a seat
temperature sensor attached to the vehicle seat trim material, such
that the seat temperature sensor only measures the temperature of
the vehicle seat trim material; an air-moving device configured to
move air across the heat sink of the thermoelectric device and
towards a seating surface of the vehicle seat; an adjustable
ergonomic device attached to the vehicle seat; wherein the control
module is operably connected to the thermoelectric device, the seat
temperature sensor, the air-moving device, and the adjustable
ergonomic device to control heating, cooling, ventilation, and
ergonomic comfort for a seat occupant.
28. The temperature control system for a ventilation, temperature
regulation, and ergonomic comfort system of claim 27 further
comprising a positive temperature coefficient thermistor-based
heater, wherein the heater is in a path of air flow of the
air-moving device.
29. The temperature control system for a ventilation, temperature
regulation, and ergonomic comfort system of claim 27 further
comprising a positive temperature coefficient thermistor at a
surface of the heat sink, wherein the thermistor is configured to
sense an overheat condition of the heat sink.
30. The temperature control system for a ventilation, temperature
regulation, and ergonomic comfort system of claim 27 wherein the
control module further comprises a user control interface.
31. The temperature control system for a ventilation, temperature
regulation, and ergonomic comfort system of claim 27 wherein the
thermoelectric device and the air-moving device share a single set
of power leads.
32. The temperature control system for a ventilation, temperature
regulation, and ergonomic comfort system of claim 28, wherein the
positive temperature coefficient heater is powered only during
warm-up of the thermoelectric device.
33. The temperature control system for a ventilation, temperature
regulation, and ergonomic comfort system of claim 27, wherein the
control module comprises a proportional, integral, and derivative
controller.
34. The temperature control system for a ventilation, temperature
regulation, and ergonomic comfort system of claim 27, further
comprising an air duct operably coupled to the air-moving device
and a positive temperature coefficient thermistor-based heater
disposed within the air duct.
35. The temperature control system for a ventilation, temperature
regulation, and ergonomic comfort system of claim 27, wherein the
control module is disposed within the vehicle seat.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent
Application No. 60/650,763, filed Feb. 7, 2006,
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an air ventilation and
conditioning apparatus for seats in general, and in particular
vehicle seats.
[0004] 2. Background
[0005] The automotive seat market faces the challenge of the high
demand for comfort. This not only involves stability and position
on the seat but also temperature and moisture of the seat. Heating
and cooling add tremendous comfort to the customers as they adapt
to the climatic situation and the body temperature.
[0006] A challenge in the last years in the seating industry
increases the demand for offering lumbar support systems combined
with seat heating/ventilation/cooling in order to respond to
customer expectations.
[0007] The present state of technology for providing a seat support
with a soft feel has been to use polyurethane foam or gummihair.
These technologies have been in the automotive market place for
many years and have met the needs for the applications. Future
demands from consumers are to incorporate additional features into
seats such as heating, cooling, and ventilation. Current foam
technologies have limitations in these applications as they do not
allow free air movement through the product very well and have high
levels of thermal mass, which decreases the effect of heating or
cooling on the surface until the foam reaches the required
temperature.
SUMMARY OF THE INVENTION
[0008] A solution to the challenges described above is to utilize a
polyester fiber fill product in conjunction with, or replacing, the
conventional foam bun. Key advantages for the fiber support include
improved breathability (eliminating perspiration and humidity from
under occupant) as well as the fact that the material can be
recycled, is lighter than foam, and provides improved noise
attenuation, all while still providing mechanical properties
equivalent to those of foam.
[0009] The present invention is a seat heat, cool, and ventilation
system designed to operate with a vehicle seat, preferably a
vehicle seat with an integrated comfort system. The seat heat,
cool, and ventilation system includes a meshwork of plastic fibers,
preferably polyester, fused together in such a manner as to permit
airflow therethrough, the meshwork makes up at least part of the
seat cushioning material. The meshwork in a preferred embodiment is
encapsulated in a relatively air-impermeable compartment having a
limited number of holes, so that air forced into the compartment
exits in a limited region of the seat, preferably where the
occupant contacts the seating surface.
[0010] Further areas of applicability of the present invention will
become apparent from the detailed description provided hereinafter.
It should be understood that the detailed description and specific
examples, while indicating the preferred embodiment of the
invention, are intended for purposes of illustration only and are
not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The present invention will become more fully understood from
the detailed description and the accompanying drawings,
wherein:
[0012] FIG. 1 is a perspective view of an integrated comfort
seat;
[0013] FIG. 2 is a side view of an integrated comfort seat;
[0014] FIG. 3A is a cross-section of a fiber pad with open fiber
construction;
[0015] FIG. 3B shows a cross-section of a fiber pad with an
impermeable barrier layer or sealed layer construction;
[0016] FIG. 3C shows a cross-section of a fiber pad with a
semi-permeable barrier layer;
[0017] FIG. 4A shows a side view of one embodiment of an integrated
comfort seat;
[0018] FIG. 4B shows a rear view of one embodiment of an integrated
comfort seat;
[0019] FIG. 4C shows a side view of another embodiment of an
integrated comfort seat;
[0020] FIG. 4D shows a side view of a manifold overmolded into
place;
[0021] FIG. 4E shows a side view of a cushion edge that is
overmolded with foam;
[0022] FIG. 4F shows a side view of the end of a manifold embedded
in a base pad;
[0023] FIG. 4G shows a side view of a flange that is attached to
the air-permeable fiber ventilation layer;
[0024] FIG. 4H shows a side view of a wire overmolded into a foam
support pad and attached via a ring to the trim layer;
[0025] FIG. 5A shows a multilayer arrangement of air-permeable
fiber mesh pads with fasteners to hold the pads in place, having a
heat-sealed edge;
[0026] FIG. 5B shows a multilayer arrangement of air-permeable
fiber mesh pads with fasteners to hold the pads in place, having a
heat-sealed edge, with an air-permeable heating layer between the
two fiber layers;
[0027] FIG. 6A shows a multilayer arrangement of air-permeable
fiber mesh pads, with a sewn edge;
[0028] FIG. 6B shows a multilayer arrangement of air-permeable
fiber mesh pads, with a sewn edge, with an air-permeable heating
layer between the two fiber layers;
[0029] FIG. 7 shows one embodiment of an integrated comfort seat,
showing the use of an optional guard and filter to diffuse air
coming from the air-moving device;
[0030] FIG. 8 shows one embodiment of an integrated comfort seat
using a belt-style lumbar support;
[0031] FIG. 9A shows an embodiment of an integrated comfort seat
using a belt-style lumbar support;
[0032] FIG. 9B shows a front view of one embodiment of a comfort
module based on a belt-style lumbar support;
[0033] FIG. 9C shows a rear view of an embodiment of a comfort
module based on a belt-style lumbar support;
[0034] FIG. 9D shows a top view of an embodiment of a comfort
module based on a belt-style lumbar support;
[0035] FIG. 10A shows a front view of an embodiment of an
integrated comfort seat using a wire flex mat support;
[0036] FIG. 10B shows a rear view of an embodiment of an integrated
comfort seat using a wire flex mat support;
[0037] FIG. 11A shows a rear view of an embodiment of an integrated
comfort seat using a belt-style lumbar support;
[0038] FIG. 11B shows a front view of an embodiment of an
integrated comfort seat using a belt-style lumbar support;
[0039] FIG. 12A shows a front view of an embodiment of an
integrated comfort seat using a flex mat lumbar support;
[0040] FIG. 12B shows a rear view of an embodiment of an integrated
comfort seat using a flex mat lumbar support;
[0041] FIG. 13 shows an embodiment of an integrated comfort seat
wherein the support pad is a fiber mesh pad;
[0042] FIG. 14 shows an embodiment of an integrated comfort seat
wherein the support pad and bolsters are fiber mesh pads;
[0043] FIG. 15 shows an embodiment of an integrated comfort seat
wherein the ventilation layer and second, or outer, layer of fiber
mesh are produced together as a single product;
[0044] FIG. 16 shows an embodiment of a comfort module based on a
flex mat support;
[0045] FIG. 17A shows a side view of one embodiment of an
integrated comfort seat;
[0046] FIG. 17B shows a perspective view of one embodiment of an
integrated comfort seat;
[0047] FIGS. 18A-18D show various embodiments of integrated comfort
seats;
[0048] FIG. 19A shows an anchor connector for attaching seat trim
material to a wire flex mat;
[0049] FIG. 19B shows seat trim material attached to a wire flex
mat;
[0050] FIG. 19C shows seat trim material attached to a wire flex
mat with the air-permeable fiber ventilation layer going around the
attachment point;
[0051] FIGS. 20A-20C show various embodiments of integrated comfort
seats;
[0052] FIG. 21 shows an embodiment of a control module for an
integrated comfort seat;
[0053] FIG. 22 shows another embodiment of a control module for an
integrated comfort seat;
[0054] FIG. 23A shows an embodiment of a thermoelectric module for
an integrated comfort seat;
[0055] FIG. 23B shows another embodiment of a thermoelectric module
for an integrated comfort seat;
[0056] FIG. 23C shows another embodiment of a thermoelectric module
for an integrated comfort seat;
[0057] FIG. 23D shows another embodiment of a thermoelectric module
for an integrated comfort seat.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0058] The following description of the preferred embodiment(s) is
merely exemplary in nature and is in no way intended to limit the
invention, its application, or uses.
[0059] An integrated comfort seat 100 comprises an ergonomic
support device 110 such as a lumbar support 120 as well as a
cushion 130 having an air-permeable ventilation layer 140 (FIGS.
1-2). In some embodiments cushion 130 also comprises a second layer
220 of fiber, as discussed below. Coupled to ventilation layer 140
is an air-moving device 150 such as a fan or blower. In general
integrated comfort seat 100 comprises one or more comfort modules
105, each having one or more heat, cool, ventilate, and ergonomic
support features, attached to a seat frame 107. Cushioning and trim
material may be integrated into comfort modules 105, may be
integral to seat frame 107, or may be added to seat 100 after
assembly of comfort modules 105. Other methods of assembling the
disclosed comfort modules 105 to produce an integrated comfort seat
100 are possible and are within the scope of the invention.
[0060] For comfort of the seat occupant as well as to allow air
movement through the seat, ergonomic support device 110 is overlaid
with one or more support pads 160, which in turn are overlaid with
the air-permeable ventilation layer 140. Although foam, such as
urethane foam, can be employed for ventilation layer 140, a
preferred embodiment utilizes a fibrous meshwork 170 comprising a
non-woven polyester fiber fill, the manufacture and use of which is
described in detail below. In contrast to fibrous mesh, current
foam technologies have limitations in these applications as they do
not readily permit free air movement through the product and have
high levels of thermal mass, which decreases the effect of heating
or cooling on the surface until the foam reaches the required
temperature.
[0061] The apparatus and methods of assembly disclosed herein are
adaptable for use with a number of different ergonomic support
devices in general and in particular to lumbar support devices such
as are mounted on a seat back, including the numerous archable
pressure surfaces (FIG. 16), belt-style lumbar supports (FIG. 11A),
and flex mat wire-based supports (FIG. 10A) that are well known to
those skilled in the art. Also, the apparatus and methods are
adaptable for use with lumbar supports and other ergonomic devices
that are programmed to provide massage by repeated cycling of the
adjustment mechanisms.
[0062] In one embodiment a foam bun is used for structural purposes
as a support pad 160 while air is circulated through the
ventilation layer 140 comprising fibrous meshwork 170 disposed on
top of the foam bun. In this case one or more holes 180 are formed
in the foam bun to permit air flow 152 through the foam to fiber
mesh ventilation layer 140 (FIG. 2). In another embodiment seat 100
has lateral bolsters 190 made of foam, laterally disposed on either
side of the seat back (FIG. 2). In addition, there are foam support
pads 160 underlying the main seating surface. In another embodiment
the foam support pads 160 underlying the main seating surface can
be replaced with additional fiber mesh pads (FIG. 13). Replacing
these foam pads with additional fiber mesh pads saves weight and
lowers the thermal mass of the cushion as a whole, allowing the
seat to heat or cool more rapidly. The additional fiber mesh pads
can optionally be circulated with air or not, depending on the
application. In yet another embodiment, the foam-based lateral
bolsters 190 can also be replaced with fiber mesh pads (FIG. 14),
again with optional circulation of air through the fiber-based
lateral bolsters 190.
[0063] In one embodiment the fibrous mesh ventilation layer 140 is
encapsulated by a non-permeable barrier layer 148 of air-tight
material(s) such as non-permeable plastic sheeting (FIG. 3B). The
air-tight encapsulation has a limited number of openings, such as
hole 180 which is provided for air intake through via air-moving
device 150 along with those openings that are provided for exhaust
through one or more holes or slits 200. On the distal or reverse
side of the mesh, away from the seat occupant, air-moving device
150 such as a fan or blower is disposed so as to move air into the
cavity of ventilation layer 140 formed by the encapsulation. On the
proximal, seating surface side of the mesh, closer to the occupant,
the sheeting or other encapsulating material 148 has one or more
distribution holes or slits 200 to permit air to move out towards
the seat occupant. Encapsulating the mesh and providing air holes
in the sheeting 148 proximal to the seat occupant has the effect of
focusing air flow 152 towards certain areas, which in a preferred
embodiment includes the areas where the occupant's body contacts
the seat surface.
[0064] A seat trim layer 210 needs to be made from
inherently-breathable materials or perforated leather and in one
embodiment is sewn together with a second layer 220 of fiber along
a sewn (FIGS. 5A, 5B) or heat-sealed (FIGS. 6A, 6B) region 222,
second layer 220 helping with air distribution and homogeneity at
the surface of seat 100. In one embodiment second layer 220 is made
from polyester fiber with a thickness of approximately 6 to 10 mm
with different densities and provides softness and improved
breathability at the seat surface, as well as improved air
diffusion and distribution. In another embodiment second layer 220
of fiber, i.e. the layer closer to the surface, is softer than the
main ventilation layer 140, for added comfort and for shaping of
the surface of seat 100. The width of sewn or heat-sealed region
222 along the edge of the fiber pad will depend on a number of
factors such as the density of fibers and in one embodiment is
approximately 10 mm wide all around (FIGS. 5A, 5B, 6A, 6B).
[0065] By having multiple fiber layers it is possible to distribute
air more evenly across the seating surface. In one embodiment (FIG.
5A) the outer, seating surface of ventilation layer 140 is
partially sealed, e.g. by repeated applications of heat to fuse
fibers together at the surface, so as to have a limited number of
holes for air to escape. Thus, air moving from air-moving device
150 will be deflected and diffused as it moves into ventilation
layer 140, since there are a limited number of exit points. This
also has the effect of forcing out similar amounts of air across
the entire ventilation layer 140 rather than permitting a
disproportionate amount of air to exit ventilation layer 140 in the
vicinity of air-moving device 150.
[0066] In another embodiment, the multilayered fiber product 226,
with or without seat trim material such as leather attached, can
also be manufactured as a separate product for installation on top
of conventional seat foam buns, for use alone or as part of an
active heat, cool, and ventilate system (FIG. 15).
[0067] A fan, blower, or other type of air-moving device 150 is
attached to a back support module 230 using known fastening means.
In one embodiment air-moving device 150 blows air out radially and
into a manifold 240 (FIG. 4B), the radial disposition of the fan
exhaust permitting the system to achieve a thinner profile. In some
embodiments support pad 160 is divided into one or more
vertically-adjacent sections 162 by at least one
horizontally-disposed channel 164, to permit independent movement
of some sections 162 so as to accommodate the movement of ergonomic
support device 110. One consequence of splitting support pads 160
is that ventilation layer 140 is also divided into multiple,
non-contiguous sections, each of which must receive a supply of
air. In one embodiment air-moving device 150 is attached to the
upper half of back support module 230, with air being carried to
the lower half by manifold 240 or other air-tight pipe, hose, or
tubing (FIG. 4A, 4B). In another embodiment ventilation layer 140
is present only on the lower portion of the back support, and thus
there is no requirement for manifold 240 (FIG. 4C). In still other
embodiments the fan, blower, or other air-moving device 150 is
attached directly to lumbar support device 120 (FIGS. 2, 8, 10A,
10B). In some embodiments, one or more fans, blowers, or other
air-moving devices 150 are attached to a wire flex mat support 250
and flex mat support 250 is pushed forward in the lumbar region by
an archable pressure surface-type lumbar support 120 (FIGS. 16,
17A, 17B, 18A, 18B).
[0068] In another embodiment, particularly where a fan blows air
directly into the fiber pad and in an axial, rather than radial,
direction, a guard 260 with an optional filter is placed over the
output region of air-moving device 150 to filter and diffuse the
air, thus preventing direct `read-through` of the blown air onto
the seat occupant's body (FIG. 7). Instead the air is spread more
evenly throughout the foam pad and therefore throughout the seating
surface for improved comfort.
[0069] In one embodiment, the support systems of the present
invention are separated into upper and lower portions by a
horizontal trough, trench, or channel 164 (FIGS. 4A, 4B). In
certain embodiments the lower portion has associated therewith an
adjustable lumbar support 120, with channel 164 separating the
upper and lower portions into independently movable sections. In
some embodiments the sections of ventilation layer 140 in the upper
and lower portions are separate from one another (FIG. 4A) while in
other embodiments ventilation layer 140 runs continuously between
the lower and upper portions (FIGS. 16, 17A, 17B). In the case
where ventilation layer 140 is separated between the upper and
lower portions of the seat support, air must be delivered
separately to each portion (FIG. 4A), for example using manifold
240 as described above. In an alternative embodiment, ventilation
layer 140 curves around and past channel 164 (FIGS. 16, 17A, 17B),
although the curves must be gradual enough to prevent creasing of
ventilation layer 140, which could restrict air flow. In this
latter embodiment, a single air-moving device 150 is sufficient to
deliver air to the entire ventilation layer 140 (FIG. 16), although
more than one can nonetheless be employed.
[0070] In some embodiments the seat cover or trim layer 210
material can be anchored directly to the back support structure,
particularly when ventilation layer 140 is separate from trim layer
210 material (FIGS. 19A-19C, 20A-20C). In this case a specialized
anchor connector 270 attaches to seat trim layer 210 material and
to the back support structure, for example to a wire that is part
of wire flex mat back support 250 (FIG. 19A). In another embodiment
seat trim layer 210 is anchored to a wire 280 that is embedded in
the seat foam, for example by overmolding of the foam onto wire
280, wire 280 being anchored to trim layer 210 by a ring 282 (FIG.
4H).
[0071] In yet another embodiment the back support is divided into
three portions to accommodate a centrally-positioned adjustable
lumbar support 120, with two separate horizontal channels 164
dividing the back support into lower, middle, and upper portions
(FIGS. 12A-12B). In one embodiment, air is provided to each
separate section of ventilation layer 140 by individual air-moving
devices 150 being associated with each portion (FIGS. 12A-12B).
[0072] In one embodiment ventilation layer 140 is encapsulated by
sealing the edges by sewing or heat sealing (FIGS. 5A, 5B, 6A, 6B)
and by fusing the fibers at the base of the pad by repeated cycles
of heat application. The outer portion of the seat pad is covered
with an air-permeable seat trim material such as an inherently
air-permeable fabric or an impermeable material such as leather
that has holes or slits 200 therein for allowing air passage (FIGS.
17A, 18A, 18C, 18D). The holes or slits may be situated so as to
coincide with the likely areas of contact between the seat
occupant's body and the trim material. As with the plastic sheeting
embodiment discussed above, in this embodiment there are also a
limited number of openings in the sealed compartment, generally in
the base, which allow air to be brought in, while air exits through
the air-permeable seat cover.
[0073] After leaving the hole(s) in the plastic sheeting or other
encapsulating material, the ventilation air moves through an
optional, air-permeable heating layer 290 and through seat trim
layer 210. Seat trim layer 210 may be inherently air-permeable
material, such as cloth, or may be a relatively impermeable
material such as leather that has been made permeable by creating
holes or slits in the material. Air-permeable heating layer is
preferably disposed between ventilation layer 140 and seat trim
layer 210. The heating material can be of conventional
construction, such as resistance wire, carbon fiber, or conductive
inks or polymers as is suitable. The attachment of the heater to
the fiber pad can be achieved in conventional means such as
double-sided adhesive, or by other suitable means known in the
art.
[0074] The heating layer comprises a number of different heating
technologies, as described below. As an alternative to
air-permeable heating layer 290, warm air is provided to seat 100
by blowing in heated air from another source such as a
thermoelectric device (TED) 300 or ambient air, if the ambient air
is substantially warmer than seat 100.
[0075] Although the text and figures focus on the seat back as an
exemplary embodiment, the same principles are applied to produce a
similar system for the seat base. In those embodiments where the
comfort system is applied to the seat back as well as the seat
base, the respective structural supports may be either separate
pieces or may be a single piece that is hinged at the transition
between the seat back and seat base.
[0076] The basic construction of the fiber mesh material of which
ventilation layer 140 is comprised is shown in FIGS. 3A-3C. In FIG.
3A, polyester fibers 142 are formed together into a mat, or fibrous
meshwork 170. Fibers 142 bond to each other at points of contact
through a heating process, for example by circulating a heated gas
such as air through the meshwork. The result is that random open
passages 144 are created which allow air to move through fibrous
meshwork 170. At the same time fibers 142 are dense and rigid
enough to provide support without collapsing. The density of
fibrous meshwork 170 can be varied, as well as to a degree the
direction of fibers 142. The technology to make the basic fiber and
to bond fibers together is well known to those skilled in the
art.
[0077] Fibers 142 can be manufactured to different densities and
thicknesses in order to have the air permeability necessary for a
complex system. In addition fibers 142 can be processed, for
example by thermoforming, to different seat shapes for various
designs in body position. In one embodiment, fiber mesh pad layers
are overmolded with foam 310 at the edges to produce a finished
appearance and to sculpt seat 100 to a desired shape and appearance
while still maintaining comfort and structure (FIGS. 4A, 4C, 4E,
4F). In another embodiment the top of ventilation layer 140 is also
overmolded with foam 310, which in one embodiment is a relatively
thin layer that permits air to flow through. The additional thin
layer of foam can be used to add comfort as well as to further
shape seat 100, while remaining thin enough so that it does not
inhibit air flow.
[0078] An additional feature that can be created with the fiber
product is that of a semi-permeable barrier layer 146 on one side
(FIGS. 3C, 5A, 6A). By applying heat to one side of the fiber, the
polyester can be reheated, melted and then cooled to form an almost
continuous air barrier. This feature can be used in applications
for heating and cooling in seats. Also, for providing comfort and
performance (heating or cooling) the fiber can be a bi-layer
product, with each layer having different densities and fiber
types.
[0079] In one embodiment the fiber pad is connected to support pads
160 by double-sided, peel and stick adhesive or mechanical
fastening such as hook and loop fasteners or other suitable
fasteners 224 (FIGS. 5A, 5B).
[0080] In one embodiment the fiber pad is made by mixing polyester
fibers having different density and thickness to create the
appropriate level of support for comfort seating while still
allowing air permeability through the seat surface.
[0081] In this construction, heating is provided by an electrical
heater located between the fiber pad and the cover. The heating
material can be of conventional construction, and use resistance
wire, carbon fiber, conductive inks or polymers as is suitable. The
attachment of the heater to the fiber pad can be achieved in
conventional means such as double-sided adhesive, or by unique
means which is afforded by the use of a fiber pad.
[0082] If air-permeable heating layer 290 is used, instead of or in
addition to a module in-line with the air circulation system such
as a TED, air-permeable heating layer 290 can be situated at
several different levels: above, below, or between the fiber mesh
pad layers. In general air-permeable heating layer 290 should be
in-line with air flow to the surface of seat 100 or at least
adjacent to the path of flowing air in order for there to be an
effective transfer of heat from the heating layer to the air and
subsequently to the seat occupant.
[0083] An alternative to integrating the heat and cool features
directly into comfort module 105 is to import conditioned air from
another source such as the vehicle's heating and air conditioning
system or from a standalone heat/cool device.
[0084] In one embodiment heat is provided by a positive thermal
coefficient (`PTC`) based heater 320 with or without thermoelectric
device 300 in the path of air flow leading to ventilation layer
(FIGS. 2, 7). PTC heaters are ceramic heating elements available in
a variety of shapes and sizes which are designed to achieve and
hold a factory-determined set-point temperature. Thermoelectric
device (`TED`) 300 comprises a thermoelectric module (`TEM`) 302,
such as a Peltier device, plus a heat sink 304. When a voltage is
applied to the Peltier device, a temperature gradient is created
across the device, creating a warm side and a cool side. If the
cool side of TEM 302 is made warmer by blowing room temperature air
across a heat sink attached to the cool side, then the warm side
will become hot. Similarly the warm side can be cooled to room
temperature to make the cool side much colder. Thus the Peltier
device can be used to provide either heating or cooling, depending
on which side of TEM 302 is maintained near room temperature, with
the resulting hot or cold air being circulated into the seat.
Furthermore, the Peltier device can also be switched between
heating and cooling by reversing the polarity of the voltage
applied to the device. In yet another embodiment heating is
provided by a layered product while cooling is achieved with TED
300 as described above. The TED device can be situated anywhere in
the path of the air leading to the seat, either upstream or
downstream of the fan or blower (FIG. 2), provided that all or most
of the air leading to the seat moves across the TED and its
associated heat sink 304. In still another embodiment the TED has
multiple layers to improve heating and/or cooling
functionality.
[0085] In one embodiment a manifold 240 is used to distribute air
to distinct compartments in ventilation layer 140. One opening of
manifold 240 is attached to a fan or other air-moving device 150
which forces air into the manifold. The output ports of manifold
240 then lead into the separate air compartments created by the
mesh fibers. To simplify assembly manifold 240, which in one
embodiment is made of plastic, may be overmolded within the foam
support pads 160 of the seat base (FIG. 4A, 4C). Ventilation layer
140 would subsequently be laid on top of support pads 160.
Alternatively, access ports for manifold 240 may be molded or cut
into support pads 160 to allow subsequent insertion of manifold
240.
[0086] In another embodiment (FIG. 4D) manifold 240 is placed
adjacent the foam support pads 160 in the area of channel 164 such
that the openings of manifold 240 are in communication with the
adjacent ventilation layer 140, and manifold 140 is then overmolded
in place. This overmolding can be performed in conjunction with
other overmolding steps such as at the edges of ventilation layer
140. The opening of manifold 240 may be a circular cross-section at
the end of a tube or may widen into an elongated slit, which in one
embodiment has a length comparable to that of the trench. In one
embodiment the distal ends of manifold 240 have ridges or
screw-type threads 244 to engage with the foam, which help to keep
the manifold in place in the foam (FIG. 4F). In another embodiment
a flange 242 is bonded to ventilation layer 140, flange 242 making
a connection, e.g. a snap fit, to the end of manifold 240 or other
air-delivery duct 370 (FIG. 4G).
[0087] In one embodiment ventilation layer 140 and second layer of
air-permeable fiber 220 are combined into a single multilayered
ventilation product 226 which can be installed on conventional
seats (FIG. 15).
[0088] The fiber pads in one embodiment are made of the synthetic
material polyester, specifically polyester fiberfill. Combining
various types of fiber and bonding methods enables the development
of products that achieve desired levels of comfort and durability
for the automotive seat market, while still permitting air to
permeate the pad when a person is sitting on it. Polyester is
recyclable, non-allergenic, and resists growth of mold and mildew.
Polyester fiberfill is available in bright, semidull, and dull
lusters. The product most often used is semidull and optically
brightened. A clean white batting color can improve the
presentation of products utilizing lightly colored fabrics.
[0089] Polyester can be treated with a variety of chemicals; to
give it non-flammable characteristics, make it anti-microbial and
improve aesthetics and durability. Polyester batting can be made to
pass all current mattress flammability standards.
[0090] Unlike polyurethane foams, polyester (PET) fiber products
will not yellow and become brittle when exposed to UV light nor
does it produce the high level of toxic gases when exposed to
heat.
[0091] The three methods of bonding are plain, resin bonded and low
melt bonded, with a preferred embodiment employing a low melt
bonding method. Low melt products are produced with a combination
of polyester fibers with different melting temperatures. It can be
made with slickened fibers, offering both aesthetics and
durability. Using a low melt bonding process, densified batting
increases durability and offers greater height recovery. Layering
of fibers can be performed by combining fibers of differing
deniers, slick/dry fiber combinations, hollow and solid fibers, and
blends of any or all of these, to achieve desired quality, price,
and performance characteristics.
[0092] Blends of other fibers including natural materials such as
wool, silk, and cashmere can also be mixed with pyron and premium
flame retardant (FR) fibers to achieve various results. Pyron is a
highly technical FR fiber that consists of oxidized
poly-acrylic-nitrile fibers. Those thermally stable oxidized
fibers, produced under high heat, resist flames. The fibers char in
place and pull heat away from the flame source. Finally, various
results can be obtained by layering different fibers, for example
using a bi-layered product as mentioned above. The top layer, for
example second layer 220, can also include exotic fibers such as
wool and silk to enhance comfort.
[0093] In one embodiment of comfort module 105 a single control
module 330 controls all of the seat comfort options disclosed
herein. By making the comfort system a single module, assembly and
installation of the comfort components into a seat is simplified
and thus costs are lowered. In addition to reducing the number of
components that must be installed, modular assembly also eliminates
the problems that can arise from a manufacturer having to fit
together various parts from different suppliers. In one embodiment
all of the seat back support and comfort elements are integrated
onto a single device (e.g. FIGS. 1, 17B) which can then be readily
attached to seat frame 107. In addition the fiber-based air
distribution pads described herein are lightweight, recyclable, and
resistant to mold and mildew growth, to name a few benefits.
[0094] Control Module
[0095] One control module 330 can be used to control all options of
seat 100 such as massage, heating, cooling, and ventilation, and
all options can be connected to one main body harness. In one
embodiment control module 330 provides for pre-heating or
pre-cooling of seats; in another embodiment the fan or blower can
be powered up in heating mode for a few seconds to improve seat air
distribution and heat-up time. To even out the temperature and to
keep heat sink 304 from building up moisture in cooling mode, in
one embodiment air-moving device 150 runs continuously for a period
of time after the cooling elements are switched to the off mode. In
another embodiment control module 330 is programmed to run
air-moving device 150 at a lower power and thus lower speed (e.g.
30% of full output) until the heating system has warmed up, to
avoid blowing cold air onto the seat occupant prior to warming up
of the heating element. In another embodiment, seat 100 can be
pre-cooled or pre-warmed, as conditions dictate, if the temperature
of the ambient air or seat 100 exceeds a preset limit, with the
pre-cooling or pre-warming being triggered by opening the vehicle
door. In one embodiment pre-cooling of seat 100 is triggered when
the seat or ambient air temperature is above 25.degree. C. The
duration of pre-heating or pre-cooling is determined by a
predetermined temperature drop or a preset amount of time. FIG. 21
shows one embodiment of controller 330, employing a rotating
selector knob. Other methods of selecting options such as heat and
cool and the temperature thereof, including push buttons with or
without light-emitting diodes, are also encompassed within the
invention.
[0096] In one embodiment control module 330 uses temperature
feedback from those parts of seat 100 that are to be heated or
cooled such as the base cushion or back layer to control the
current and/or voltage to air-permeable heating layer 290 and/or
thermoelectric device 300 in-line with air-moving device 150 to
reach a user-selectable temperature in a minimum time and to keep
that temperature constant. In one embodiment a PID (Proportional,
Integral and Derivative) controller, well known to those skilled in
the art, is used as part of control module 330 to control the
temperature of seat 100. After the surface of seat 100 reaches a
preset temperature, the fan speed in one embodiment is reduced to
decrease the noise if the blower is turned on and to reduce any
user discomfort that might arise from excess air movement.
[0097] In heating mode, the heater, which in one embodiment is
air-permeable heating layer 290, will be turned on by the PID
controller. In this case, after a delay period (typically 30
seconds), air-moving device 150 will blow air to the occupant at
low speed and, after a short period of time, in an intermittent
manner. Thus, by using forced air, even when using air-permeable
heating layer 290, warm air is forced from the heat layer to the
occupant instead of relying only on passive transfer (e.g.
conductive heat transfer or local convection currents) to move heat
to the occupant through ventilation layer 140 and seat trim layer
210. The advantage is to shorten the heat-up time and achieve a
more uniform heating up. The heater, e.g. a PTC-based heater 320,
can be a separate heater inside an air duct 370 attached to heat
sink 304, and can be used alone or in conjunction with TED 300
operating in heating mode. In this case, air-moving device 150 will
blow the air at low speed at the beginning to permit the air to
have enough time to be heated up.
[0098] In cooling mode, TED 300 will be powered and air-moving
device 150 will blow cold air to the seat occupant. The optionally
PID-based control module 330 will control the current and/or
voltage to thermoelectric device 300 as well as the speed of
air-moving device 150. If the ambient temperature inside the
vehicle is considerably lower than the temperature of seat 100,
which in one embodiment is a difference of between 10 to 20 Celsius
degrees lower, TED 300 will be shut off and seat 100 will be cooled
by blowing ambient air at maximum speed to save energy. When the
ambient temperature within the vehicle is closer to the temperature
of seat 100, which in one embodiment is a difference of between
less than 10 to 20 Celsius degrees, TED 100 will be powered and
thus air that is significantly lower than ambient temperature will
be blown to the seat surface to effect cooling of seat 100. In one
embodiment a temperature sensor 340 is placed near the inlet of
air-moving device 150 for a more accurate measurement of the
temperature of the ambient air that will be delivered to the
surface of seat 100, as well as to achieve a more compact, modular
design overall. In another embodiment temperature sensor 340 is
placed directly beneath seat trim layer 210 to measure the
temperature of seat trim layer 210 itself. In this embodiment
temperature sensor is isolated from air flow 152 to sense the
temperature of seat trim layer 210 material alone (FIG. 2).
[0099] A user control interface 334, such as push buttons, knobs
and indicators such as light-emitting diodes (LEDs) can be mounted
on seat 100 or the vehicle's dash or can stand alone through wired
or wireless transmission. A control signal can also be obtained
from the vehicle heater and air conditioner control settings, thus
eliminating the need for a separate control module.
[0100] A programmable timer 332 (FIG. 22) can be integrated into
control module 330 so that seat 100 can be heated up or cooled down
at a certain preset time, for example a particular time of day, and
the occupants can immediately enjoy the comfort when they enter the
vehicle.
[0101] A signal from the door unlock by a remote entry system can
also be used to turn on the system automatically. In the case where
the seat temperature control automatically turns on, for example
using a preset timer or the door unlock signal, the module will
turn the system on heating or cooling mode based on conditions
manually preset by the user, or alternatively based on factory
pre-set conditions. For example, in one embodiment control module
330 will activate the cooling mode if the ambient temperature is
higher than 25.degree. C. (user-configurable) and it will activate
the heating mode if the ambient temperature is lower than
20.degree. C. (user configurable). In one embodiment, if the
occupant does not sit on the seat within 10 minutes after the
system automatically turns on (through an optional occupant sensor)
or the engine is not turned on within this time period, the system
will shut off to save power.
[0102] A temperature sensor 340 attached to TED 300 or its heat
sink 304 will be used to prevent overheat of the thermoelectric
module, or TEM, 302.
[0103] Air-moving device 150 will remain on for a certain time
(typically 30 seconds) to bring heat sink 304 of TED 300 closer to
ambient temperature and thereby prevent any possible build-up of
moisture on the cooled TED 300, especially in hot and humid summer
weather, before shutting off completely.
[0104] A memory feature can be added to store the preferred
temperature settings for each of several seat occupants.
[0105] In one embodiment the seat temperature control module 330 is
made to operate without a user-adjustable control module, i.e. it
is made to be self-adjusting. In this embodiment a user's input
would be limited to selecting whether to heat or cool the seat,
with the system otherwise being self-adjusting. By using a
PTC-based (Positive Temperature Coefficient thermistor) heater 320,
wherein a set-point thermistor is integrated into a heating device
to maintain a factory-determined temperature, to provide heat
either through the air or directly transferred to the occupant, the
system will maintain a certain temperature and will not overheat.
In an alternative embodiment, a PTC thermistor 350 is used to limit
the power to TED 300 even where TED 300 is used for heating, to
provide overheat protection.
[0106] As for cooling, a Negative Temperature Coefficient
thermistor (NTC) 360 (FIG. 22) will limit the current to TED 300
when the temperature inside air duct 380, near the occupant, or in
the ambient air reaches a certain point. When the temperature
surrounding NTC 360 decreases to a certain point the resistance of
NTC 360 increases, thereby reducing power to TED 300 and preventing
overcooling. Alternatively, PTC thermistor 350 will be put on the
`hot` side of TED 300 to limit the power to TED 300.
[0107] An optional timer can be added to shut off the system after
a pre-defined amount of time.
[0108] The wiring can be changed so that in heating mode, two or
three PTC-based heaters 320 can be turned on to achieve a high
temperature setting, while two or just one heater can be turned on
for a medium temperature setting, and only one or some combination
can be turned on for a low temperature setting (FIG. 22). Again,
because PTC-based heaters stay at their pre-set temperature, this
eliminates the need for a controller or/and temperature sensors. In
an alternative embodiment, each PTC heater 320 can be of a
different power level, such that turning on a first heater puts the
system in low heating mode; turning on a second heater and turning
off the first puts the system into medium heating mode; and turning
on a third heater while the first and second are off puts the
system into high heating mode (FIG. 22).
[0109] NTC thermistors 360 are put in air duct 370 to sense the
cold air in cooling mode (FIG. 22). In an alternative embodiment,
PTC thermistors 350 can be put on the hot side of TED 300 either
close to or touching heat sink 304 (FIG. 23A) or put in the exhaust
air duct 370.
[0110] The wiring for the PTC or NTC thermistors can be configured
to be either in parallel or serial or any combination, as is well
known to those skilled in the art.
[0111] Safety Features:
[0112] Positive temperature coefficient thermistors (PTCs) 350 can
also be used for overheat protection, even in embodiments in which
a user-operable control system is employed. In one embodiment a PTC
thermistor 350 can be used to prevent TED 300 from overheating in
case of control module failure, blower failure, or air duct 370
being blocked, among various possibilities. When TED 300 is working
(in this case, not with a PTC in self-adjusting mode), air-moving
device 150 must also work to cool down the `hot` side of TED 300.
If for any reason air-moving device 150 were to stop working while
TED 300 was still powered, TED 300 would overheat, which could
cause damage to the system or even seat 100 and may cause safety
issues. Two PTCs 350 can be put anywhere near the surface of TED
300, one of each on both sides, and put TED 300 in serial with PTC
350 (FIG. 23A). This way whether TED 300 is in heating or cooling
mode the PTC thermistor 350 will shut off the power if either side
of TED 300 is overheated. The PTC thermistor 350 will reset itself
when the overheating condition is removed.
[0113] Provision of Overheat Protection without a Temperature
Sensor for the TEM
[0114] The thermoelectric modules that are used here are subject to
the Seebeck effect which will generate a voltage because of the
temperature difference between the two sides of the thermoelectric
module (TEM). When TEM 302 is powered, the current generates a
temperature difference between the two sides. If for any reason
heat sink 304 that is attached to TEM 302 is not cooled down, e.g.
due to blower failure, air duct blockage etc., the temperature
difference between the two sides will increase, leading to an
increase in voltage due to the Seebeck effect. The result is that
the current through TEM 302 will decrease. A current sensor will
monitor the current to TEM 302 and the module will shut down or
lower the power to TEM 302 if the current is less than 0.5A
(typically, this value will depend on the specific type of module)
of the normal running current. That is, since current running
through the two sides of TEM 302 is proportional to the
temperature, the temperature of TEM 302 can be monitored indirectly
by monitoring current. When the current running through TEM 302
drops below a certain level, this is taken to indicate an excessive
temperature difference between the two sides of TEM 302 and power
is decreased or shut off to TEM 302 as necessary. In this way
production costs for the control system can be reduced by
eliminating temperature sensors and the wires to these sensors.
[0115] Power Feed to the Blower, TED/PTC Assembly
[0116] TED 300 and air-moving device 150 can be configured to share
the same power leads 372, thereby simplifying production and
reducing costs, particularly since TED 300 and air-moving device
150 are usually located in a single housing 376 (FIG. 23C). One
problem to overcome in such a configuration, however, is that the
polarity of the voltage sent to TED 300 may be reversed in order to
switch between heating and cooling, while air-moving device 150
requires a uniform polarity voltage. In one embodiment a bridge
rectifier or other similar circuit 374 known to those skilled in
the art can be used to provide a uniform polarity voltage to power
air-moving device 150 regardless of the polarity of the incoming DC
current (FIG. 23C). In another embodiment a control signal from
control module 330 is used to control the direction of the DC
current through TEM 302 (FIG. 23C). On the other hand, if TEM 302
is only used for cooling while heating is provided by separate
heater, then no polarity switching is needed and the blower and the
TED can be put in parallel to share the same power feeds.
[0117] In yet another embodiment a control signal from control
module 330 can change the speed of air-moving device 150 (FIGS.
23C, 23D).
[0118] The advantage of having air-moving device 150 and TED 300
using the same power leads is that TED 300 will always be cooled by
air-moving device 150 whenever TED 300 is working, and TED 300 will
shut down if air-moving device 150 shuts down in case of failure of
control module 330.
[0119] Enhanced Heating Performance
[0120] PTC heaters 320 can be put on one side of TED 300 where the
air is blown to the seat surface to supplement the heat generated
by TED 300 (FIG. 23B). Alternatively, PTC-based heater(s) 320 can
be put in air duct 370, either downstream (FIG. 23C) or upstream
(FIG. 23D) of TED 300. In heating mode, PTC heater(s) 320 will be
powered up first. TED 300 will be powered up gradually with the
decrease of the current draw from PTC heater(s) 320, maintaining an
overall current draw within the limit. The advantage is to achieve
a faster heat up time and power efficiency. The switchover from
heating with PTC heater 320 to TED 300 can be determined either as
a function of time (which in one embodiment is fifteen seconds
after startup) or in another embodiment as a function of current
draw. A PTC heater typically draws more current at initial startup.
As it is reaching the stabilized state, it draws a smaller current.
The current is monitored so that TED 300 can be switched over so
that the total current draw is within a certain predetermined
limit. This option can also be used for moisture removal for the
TED: 1. switch TED 300 on cooling mode and blow air; 2. turn off
TED 300 and turn on PTC 320 to blow warm air across heat sink 304
(FIG. 23B); 3. shut off system.
[0121] In heating mode, PTC heater 320 on the `hot` side of TED 300
will generate heat to be transferred to the occupant via forced
air, either working with or without TEM 302. If TEM 302 is also
powered to provide the heat, it can be controlled to work at a
lower capacity to guarantee it will not overheat. By using two heat
sources, heat-up time will be shortened.
[0122] Optional temperature sensors or the methods described above
will be used by control module 330 to provide overheat protection.
If overheating is detected, power to TEM 302 will be shut off.
[0123] As various modifications could be made to the exemplary
embodiments, as described above with reference to the corresponding
illustrations, without departing from the scope of the invention,
it is intended that all matter contained in the foregoing
description and shown in the accompanying drawings shall be
interpreted as illustrative rather than limiting. Thus, the breadth
and scope of the present invention should not be limited by any of
the above-described exemplary embodiments, but should be defined
only in accordance with the following claims appended hereto and
their equivalents.
* * * * *