Air cushion for chair and chair utilizing the air cushion

A vehicle seat assembly is provided having a inflatable bag positioned within its seat cushion. The bag comprises first and second fabric members joined by a rib fabric member. Each first and second member is a laminate consisting of a meshed middle fabric sandwiched between two thermoplastic resin layers adhered to one another via the meshes. Only the outer peripheries of the two resin layers are in direct sealing contact with one another. An air port is sealingly connected to the first or second member to allow air to be supplied or removed from the bag to change its contour.

BACKGROUND OF THE INVENTION 
1. Technical Field of the Invention 
This invention relates to an inflatable air support device for a chair, and 
more particularly to an improvement of the air support to be used in an 
automobile and the improved air support. 
2. Discussion of the Related Art 
This kind of conventional air support is a mere air bag and there is a 
major trend to use this air bag such that air is fed into or discharged 
from it to expand or retract the air bag. 
Therefore, no air bag was found in which only one air support could fit the 
body of the user. Even in case that the above-mentioned air support was 
stored in the seat cushion or seat back, the air support was merely stored 
in it, so that even if air was poured into the bag, the surface of the 
seat cushion or seat back merely showed a bulging action, and this type 
did not fit to the body of the user and so it showed some disadvantages 
that some effect of holding of the seated person and removing a feeling of 
fatigue could not sufficiently be attained. 
This invention is one in which the abovementioned disadvantages of the 
prior art are eliminated for its object. 
SUMMARY OF THE INVENTION 
According to a first invention, there is provided an inflatable air support 
device for a chair comprising a suspension fabric is arranged between the 
upper opposed surface and the lower opposed surface or the side fabric in 
the main body of the expandable air bag, said surfaces being formed into a 
rugged configuration. With this, it is possible to provide a chair having 
a fitness by the provision of the rugged configuration in the surfaces 
unlike the conventional air bag. According to a second invention, there is 
provided an air support for chair characterized in that the main body of 
the expandable air bag and part of or the whole suspension in the first 
invention are formed of tarpaulin. Therefore, as compared with the first 
invention, even if the force more than as needed is applied to the main 
body of the air bag and the suspension fabric, they are not deformed and 
in addition have the strengthening property, thus increasing the 
durability. 
According to a third invention, there is provided an air support for chair 
in which permeable urethane foam is inserted into the main body of the air 
support for chair according to the first invention. Therefore, as compared 
with the first invention, an air feed and discharge device is not always 
required, and a highly useful air support for chair may be obtained. 
According to a fourth invention, there is provided an air support for chair 
in which in the main body of the air support for chair according to the 
first invention, the main body of the expandable air bag and part of or 
the whole suspension fabric are formed of tarpaulin to constitute the body 
of the air support, and permeable urethane foam is inserted into the main 
body of the air support. An air feed and discharge device is not always 
needed while possessing the configuration retaining property, and a 
further improvement is applied to the first invention. 
According to a fifth invention, there is provided a chair utilizing the air 
support characterized in that the air support body for chair according to 
the first to fourth inventions is sealed into one or both seat cushion and 
a seat back, which is the invention showing the utilizing place of the 
first to fourth inventions. This fifth invention clearly shows that the 
utilization of the seat cushion or seat back or both of them for the chair 
is useful. 
There is further provided a method for manufacturing a chair with an air 
support characterized by the steps of putting the air support for chair 
according to the first to fourth inventions into the central portion in 
the mold for the seat cushion or seat back, filling the whole periphery of 
the air support for chair with a liquid of expandable foaming material, 
and thereafter solidifying said liquid to remove it from the mold, thus 
forming the seat cushion or seat back. This is the best method for 
manufacturing a chair utilizing the air support according to the first to 
fourth inventions. 
Next, a seventh invention provides a chair utilizing an air support which 
comprises: 
i. Air pump for supplying air, 
ii. an expandable member encased in position of a vehicle seat to supply 
and discharge the air supplied by said air pump, 
iii. a support plate provided along a predetermined part in the back of a 
surface layer member constituting a surface portion of the vehicle seat, 
said support plate being moved in and out f the seat surface by the 
expansion of said expandable member, which elements i, ii and iii above 
constitute a seat support device for the vehicle seat, and 
iv. said expandable member comprising two sheets whose peripheral edges are 
sealed to form an air bag body, a plurality of such air bag bodies being 
placed one above another, predetermined points of a contact surface 
between the air bag bodies adjacent to each other being joined, and said 
joined portions being formed with vent holes to provide a communication 
between the air chambers of the air bag bodies. This invention improves 
over the utilizing means in connection with the first to fourth 
inventions, providing an expansion property in the surface of the chair 
with planar positiveness.

DETAILED DESCRIPTION OF THE INVENTION 
(Best Mode for Embodying the Invention) 
Referring now to the drawings, some preferred embodiments of the present 
invention will be described. 
(Embodiments) 
In the first preferred embodiment, it is constructed such that a 
rectangular suspension fabric (2) is arranged between the upper opposed 
surface (1a) and the lower opposed surface (1b) in the main body (1) of 
the air bag and the suspension fabric (2) is applied for making a 
rectangular cross section when the main body (1) of the air bag is 
expanded. The main body (1) of the air bag is formed to show a planar 
rectangular shape by overlapping two sheets of thermoplastic soft urethane 
resin and thermally heating an entire circumference of the sheets and an 
air feeding and discharging port (3) to be connected to a pump (not shown) 
is provided at one of the front and rear surfaces. 
The suspension fabric (2) is of the same material quality as that of the 
main body (1) of the air bag, and one sheet of fabric is placed on a 
center line of a longitudinal side in the main body (1) of the air bag as 
shown in FIG. 1 or one sheet of fabric is placed on the center line of a 
short side in the main body (1) as shown in FIG. 3, and the upper and 
lower longitudinal sides are thermally melted to the upper opposed surface 
(1a) and the lower opposed surface (1b) in the main body (1), 
respectively. The length of the suspension fabric (2) is slightly shorter 
than either a longer side or a shorter side of the main body (1) of the 
air bag, and therefore an air chamber in the main body (1) is maintained 
in a unitary form without being separated by the suspension fabric (2). 
The suspension fabric (2) could be used in its tubular form. 
Further, referring to FIGS. 13, 14 and 15, a more detailed description 
shows that in order to facilitate a folding of the air bag, the suspension 
fabric (2) may be made such that two sheets of base fabrics are overlapped 
to each other and one side part is adhered and they are applied with a 
permanent line to overlap at their center points. And, referring to FIGS. 
32 and 33, it may also be possible to overlap two sheets of fabrics, to 
adhere both sides of the fabrics to form a tubular shape, and the upper 
and lower central portions are adhered to the upper opposed surface (1a) 
and the lower opposed surface (1b), respectively. 
The air bag of the first preferred embodiment as described above is 
operated such that when the air is supplied to the main body (1) of the 
air bag through a feeding and discharging port (3), the main body (1) is 
expanded while the clearance between the upper opposed surface (1a) and 
the lower opposed surface (1b) is kept constant by the suspension fabric 
(2), the cross sectional shape in case of bulged main body (1) is kept as 
a rectangular form and then the front and rear surfaces of the main body 
become flat. 
In the first preferred embodiment, the suspension fabric is applied as one 
fabric but as shown in FIGS. 4 to 12, 31 and 33, a plurality of suspension 
fabrics, for example, two to three suspension fabrics may also be arranged 
in parallel. In this way, if a plurality of suspension fabrics are 
arranged, an effect of holding shape of the main body of the air bag may 
be increased, the cross sectional shape of the main body can be made more 
approximate to a rectangular shape and then the surface of the main body 
can positively be a flat surface. 
In the second preferred embodiment, as shown in FIG. 4, the suspension 
fabric (2) arranged at the upper opposed surface (1a) and the lower 
opposed surface (1b) in the main body (1) of the air bag is formed as a 
triangular shape or as shown in FIGS. 5 and 6, a plurality of, for 
example, two rectangular suspension fabrics (2) are arranged so as to 
divide unevenly the main body (1) in a direction of short side or long 
side and the height of each of the suspension fabrics (2) is gradually 
increased in their parallel direction. In case that the triangular 
suspension fabric (2) is to be installed, the number of fabrics may be 
either one or a plurality of fabrics. In case that one suspension fabric 
(2) is applied, the suspension fabric (2) is arranged on the center line 
of the short side or long side of the main body (1) of the air bag and in 
case of a plurality of suspension fabrics, it is preferable to arrange 
each of the suspension fabrics so as to make an equal division of the main 
body (1) of the air bag in its short side or long side direction in such a 
way as it may make an effect of holding of uniform shape. 
The second preferred embodiment as described above is operated such that 
when the main body (1) of the air bag is expanded, a clearance between the 
upper opposed surface (1a) and the lower opposed surface (1b) is gradually 
increased by the suspension fabric (2) or (2) in its short side or long 
side direction, the cross sectional shape of the main body (1) of the air 
bag becomes a triangular shape and then the surface of the main body 
becomes an inclined or slant surface. 
The third preferred embodiment is constructed such that as shown in FIG. 7, 
the suspension fabric (2) has an arcular side recessed from one 
rectangular longitudinal side, a plurality of, for example, two suspension 
fabrics (2) are arranged in parallel in a direction of short side or 
longitudinal side of the main body (1) of the air bag, or a plurality of, 
for example, four rectangular suspension fabrics (2) are arranged in a 
direction of short side or longitudinal side so as to divide the main body 
(1) of the air bag as shown in FIG. 8, and the height of each of the 
suspension fabrics (2) has a higher one at its outer side and a lower one 
at its inner side, respectively. 
The third preferred embodiment as described above is operated such that 
when the main body (1) of the air bag is expanded, a clearance between the 
upper opposed surface (1a) and the lower opposed surface (1b) is varied in 
a quadratic curve fashion with the suspension fabric (2) or a plurality of 
suspension fabrics (2), the cross sectional shape of the main body (1) of 
the air bag becomes such a shape as one rectangular longitudinal side 
being concaved to an arcular shape, resulting in that the entire surface 
becomes a concave surface. 
The fourth preferred embodiment is constructed such that as shown in FIG. 9 
the suspension fabrics (2) are of such a shape as having longitudinal 
sides of rectangular shape recessed to show a sine curve, the 
above-mentioned suspension fabrics (2) are arranged such that a plurality 
of suspension fabrics, for example, three fabrics are arranged in parallel 
in a direction of short side or longitudinal side of the main body (1) of 
the air bag, or as shown in FIG. 10, a plurality of, for example, five 
rectangular suspension fabrics (2) are arranged in such a way as the main 
body (1) of the air bag is equally divided in a direction of short side or 
longitudinal side, the height of each of the suspension fabrics (2) is 
made higher at its intermediate one and both outer ones and the suspension 
fabric held between them is made lower one. 
The fourth embodiment as described above is constructed such that when the 
main body (1) of the air bag is expanded, it is held in such a way as a 
clearance between the upper opposed surface (1a) and the lower opposed 
surface (1b) is varied in a sine curve fashion with the suspension fabric 
(2) or a plurality of suspension fabrics (2) and then the cross sectional 
shape of the main body (1) of the air bag becomes one in which one 
rectangular longitudinal side has a sine curved shape and the surface of 
the main body becomes a curved surface having a raised part and a concave 
part. 
The preferred embodiment of the suspension fabric (2) could be utilized as 
shown in FIGS. 30 and 31, or FIGS. 32 and 33. With this arrangement, it is 
possible to facilitate a provision of the corrugated surfaces on the upper 
opposed surface (1a) and the lower opposed surface (1b), resulting in 
making a smooth fit to a human body. 
Further, as shown in FIGS. 11 and 12, the main body (1) of the air bag is 
provided with a rectangular suspension fabric (2) over a clearance between 
the inner opposed surfaces (1a) and (1b) and further with an air feeding 
and discharging port (3) to be connected to a pump (not shown) at its rear 
surface. 
The suspension fabrics (2) are of the same material quality as that of the 
main body (1) of the air bag, they are arranged in parallel in a properly 
spaced-apart relation in circumferential direction of the main body (1) 
and each of the upper and lower edges is welded to the upper opposed 
surface (1a) and the lower opposed surface (1b) in the main body (1). The 
length of the suspension fabrics (2) is slightly shorter than the 
longitudinal side of the main body (1) of the air bag and therefore the 
air chamber in the main body (1) of the air bag is partitioned by the 
suspension fabrics (2) to constitute the sub-air chambers (4). The length 
of the suspension fabrics (2) may correspond to the length of the 
longitudinal side of the main body (1) of the air bag. 
The sub-air chambers (7) are made such that some belt-like sheets (5) cut 
to the desired width are arranged over the entire length of the 
above-mentioned thermal melted part and its entire circumferential edges 
are melted and adhered to the surface of the main body (1). 
The above-mentioned belt-like sheets (5) are applied in tension over a 
space between the portions starting a concave part at both sides of 
groove-like concave part which is formed along the supporting locations 
for the suspension fabrics (2) of the surface of the main body, and the 
widths of the above-mentioned belt-like sheets (5) and the small sub-air 
chambers (7) are defined in response to the width of the above-noted 
groove-like concave portions. 
The surface of the main body (1) of the air bag in the small sub-air 
chambers (7) is provided with some communication holes (6) so as to 
communicate the interior of the main body (1) with the small sub-air 
chambers (7). 
The main body (1) of the air bag in the above-mentioned preferred 
embodiment is operated such that when air is supplied through feeding and 
discharging ports (3) of the inner plugs, the opposed inner surfaces of 
the main body (1) are expanded with a specified clearance being kept by 
the suspension fabrics (2), their cross sectional shapes are kept in a 
rectangular form, sub-air chambers (4) may be independently formed or 
communicated to each other. In this case, some groove-like concave 
portions are formed along the supports at the edges of the suspension 
fabrics (2) at the surfaces of the main body (1) of the air bag and the 
concave portions are hidden by being covered by belt-like sheets (5) by a 
method wherein the small subchambers (7) arranged along the concave 
portions are expanded together with the main body (1). 
In the above-mentioned preferred embodiment, it is optional that the number 
of suspension fabrics (2) is decreased down to one suspension fabric or 
increased up to three to four fabrics and they may be arranged in a 
direction of the short side of the main body (1) of the air bag, and also 
in this case the small sub-air chambers (7) are arranged at the supporting 
parts for each of the suspension fabrics (2) at the surface of the main 
body (1) of the air bag and thus the surface of the main body (1) is kept 
flat. 
In addition, as shown in FIGS. 13 and 14, each of the upper opposed surface 
(1a) and the lower opposed surface (1b) of the main body (1) of the air 
bag is provided with openings (8), and the suspension fabrics (2) are 
arranged over the circumferential edges of these openings (8). 
The main body (1) of the air bag is constructed such that two sheets of 
thermoplastic soft urethane resin are overlapped to each other and the 
entire circumferences of the sheets are thermally melted and adhered to 
each other to form a planar rectangular shape, and one of the upper 
opposed surface (1a) or the lower opposed surface (1b) is provided with an 
air feeding and discharging port (3) to be connected to the pump (not 
shown). 
Each of the openings (8) arranged in the above-noted upper opposed surface 
(1a) and the lower opposed surface (1b) is of an ellipse o circle having 
the same diameter, is positioned at the central portions of the upper 
opposed surface (1a) and the lower opposed surface (1b) and has a 
relatively large opening area. 
The suspension fabrics (2) are of the same material quality as that of the 
main body (1) of the air bag, two endless belt fabrics (2a) and (2b) are 
thermally melted and adhered to each other to form a gusset and 
constructed in such a way as they may be folded, and the upper and the 
lower circumferential edges are thermally melted and adhered to the 
circumferential edges of the openings. 
The main body (1) of the air bag of the preferred embodiment as described 
above is operated such that air is fed from the feeding and discharging 
port (3) to expand the main body (1), resulting in that a clearance 
between the circumferential edges of the openings (8) of the upper opposed 
surface (1a) and the lower opposed surface (1b) on the sheet is uniformly 
kept by the suspension fabrics (2), the clearance holding action is 
extended up to the upper opposed surface (1a) and the lower opposed 
surface (1b) around the openings (8) and then the clearance between the 
upper opposed surface (1a) and the lower opposed surface (1b) is kept 
uniform. Under such a condition as the main body (1) of the air bag is 
expanded, each of the surfaces (1a) and (1b) is flat. In case that the 
main body (1) of the air bag is retracted, as shown in FIG. 13, the 
suspension fabrics (2) are folded into the main body (1) of the air bag by 
their gusset structures. FIG. 15 illustrates the retracted condition of 
the preferred embodiment shown in FIG. 13. 
The preferred embodiment of the present invention will be further described 
in reference to the drawings. 
The main body (1) of the air bag is constructed such that as shown in FIGS. 
16 and 17, a tubular suspension fabric (2) is arranged over a clearance 
between the inner opposed upper surface (1a) and the lower opposed surface 
(1b). 
The main body (1) of the air bag is formed such that transparent front and 
rear sheets of thermoplastic soft urethane resin are overlapped to each 
other, then the suspension fabric (2) is thermally melted and adhered to 
the desired locations at the opposed surfaces of both sheets, thereafter 
the entire circumferential edges of both sheets are thermally melted and 
adhered to each other to form a planar rectangular shape. 
The above-noted suspension fabric (2) is formed to a tubular shape with the 
same material quality as that of the main body (1) of the air bag, is 
extended in a direction of longitudinal side at the central part between 
the upper opposed surface (1a) and the lower opposed surface (1b) of the 
main body (1) of the air bag, two locations of the uppermost part and the 
lowermost part acting as the contacted portions between the above-noted 
opposed surfaces (1a) and (1b) at the circumferential surface of the 
suspension fabric (2) are thermally melted and adhered with a specified 
width to the upper opposed surface (1a) and the lower opposed surface (1b) 
and fixed thereto. 
As described above, in order to fix the uppermost part and the lowermost 
part at the circumferential surface of the suspension fabric (2) to the 
upper opposed surface (1a) and the lower opposed surface (1b) with a 
specified width, as shown in FIGS. 16 and 17, two locations at both sides 
of the fixed width at the circumferential surface of the suspension fabric 
(2) are thermally melted and adhered in a linear form over the entire 
length of the suspension fabric (2) or as shown in FIG. 18 the entire 
surface of the fixed width of the circumferential surface of the 
suspension fabric (2) is thermally melted and adhered. 
A process for thermally melting and adhering the suspension fabric (2) to 
the upper opposed surface (1a) and the lower opposed surface (1b) in a 
practical manner will be described in reference to FIGS. 19 to 22. 
As shown in FIG. 19, the suspension fabric (2) is inserted and fitted to a 
rod-like lower electrode (C.sub.1), the sheet-like upper opposed surface 
(1a) is placed on the suspension fabric (2) to set its position, then an 
upper electrode (C.sub.2) is forcedly contacted onto the sheet-like upper 
opposed surface (1a) to hold the uppermost part of the suspension fabric 
(2) and the sheet-like upper opposed surface (1a) together with the lower 
electrode (C.sub.1), then both electrodes (C.sub.1) and (C.sub.2) are 
energized to perform a thermal melting and adhesion. Then, the position 
where the lower electrode (C.sub.1) is applied is displaced by a distance 
corresponding to the desired fixed width in a circumferential direction of 
the suspension fabric (2) as shown in FIG. 20, and both the suspension 
fabric (2) and the sheet-like upper opposed surface (1a) are held by both 
electrodes (C.sub.1) and (C.sub.2), thereafter they are thermally melted 
and adhered as shown in FIG. 21. 
As described above, the suspension fabric (2) and the sheet-like upper 
opposed surface (1a) are thermally melted and adhered, thereafter the 
suspension fabric (2) is rotated by a half distance while it is inserted 
into the lower electrode (C.sub.1), the circumferential surface of the 
suspension fabric (2) which is just opposite to the fixed part of the 
suspension fabric (2) thermally melted and adhered as described above is 
faced upward, the surface part is thermally melted and adhered to the 
fixed position of the sheet-like lower opposed surface (1b) in the same 
manner as that of the sheet-like upper opposed surface (1a), and then the 
suspension fabric (2) is applied over both upper and lower opposed 
surfaces (1a) and (1b). 
Since the suspension fabric (2) is of a tubular form, if it is inserted 
into the rod-like lower electrode (C.sub.1), the forcedly contacted 
surface of the electrode (C.sub.1) is held automatically while it is 
contacted with the inner uppermost surface of the suspension fabric (2), 
resulting in that an operation for setting the melted and adhered part of 
the suspension fabric (2) to the lower electrode (C.sub.1) and the 
operation for holding it under such a condition as above may be eliminated 
and then the sheet-like upper opposed surface (1a) is fixedly held 
manually on the suspension fabric (2) held under the above-mentioned 
condition, held by the upper electrode (C.sub.2) and the sheet may be 
thermally melted and adhered in a simple and easy operation by energizing 
the upper and lower electrodes (C.sub.1) and (C.sub.2). 
Both upper and lower opposed surfaces (1a) and (1b) having the suspension 
fabric (2) thermally melted and adhered form the planar rectangular main 
body (1) of the air bag by a thermal melting and adhering of the entire 
circumferential edges with each other and further a feeding and 
discharging port (3) is arranged at the rear surface of the main body (1). 
In this case, both ends of the suspension fabric (2) are held between the 
upper and lower opposed surfaces (1a) and (1b) to make an integral thermal 
melting and adhering. 
With this arrangement, the suspension fabric (2) is held such that its both 
ends are collapsed in a direction of shrinkage of the main body (1) of the 
air bag and the entire suspension bag (2) is collapsed flat. Thus, when 
the main body (1) of the air bag is shrinked, the suspension fabric (2) is 
lightly collapsed together with the main body (1) of the air bag and no 
useless projections are generated at the surface of the main body (1) as 
shown in FIG. 22. 
Both upper and lower suspension fabrics (2a) and (2b) holding the upper and 
lower fixed parts at the circumferential surface of the suspension fabric 
(2) are tensioned in an expanding direction with a tension force of the 
main body (1) of the air bag and are deformed to show a rectangular cross 
section as shown in FIG. 17. Thus, air through-pass holes (9) are made at 
the circumferential surface of the suspension fabric (2) so as to cause 
the air in the main body (1) of the air bag to be flowed freely, a 
deformation of the suspension fabric (2) is freely made and at the same 
time the small sub-chambers (4) are made independent one. 
A permanent folding line is applied in advance at the circumferential 
folding part in the suspension fabric (2) to cause the suspension fabric 
(2) to be easily collapsed, the length of the suspension fabric (2) is 
made slightly shorter than the long side of the main body (1) of the air 
bag, the air chamber in the main body (1) of the air bag is kept in a 
unitary form without being partitioned by the suspension fabric (2). In 
this case, the suspension fabric (2) may not be provided with the 
through-pass holes (9). 
The main body (1) of the air bag in the preferred embodiment as described 
above is operated such that both upper and lower suspension fabrics (2a) 
and (2b) are tensioned in a tensile direction upon feeding of air through 
the feeding and discharging port (3) and the clearance between the upper 
opposed surface (1a) and the lower opposed surface (1b) of the main body 
(1) of the air bag is kept uniformly. At this time, since both side 
surfaces of the suspension fabric (2) are tensioned with each other with a 
distance of the fixed width, it may show the same holding effect as that 
obtained in the case that two suspension fabrics are arranged in parallel 
with the above-noted distance, the upper opposed surface (1a) and the 
lower opposed surface (1b) of the main body (1) of the air bag are 
uniformly held at two points, their cross sectional shapes are held more 
accurately than that of a piece of suspension fabric, and both front and 
rear surfaces of the main body (1) of the air bag are formed to an 
approximate planar flat surface. 
It is of course optional that in the above-mentioned preferred embodiment, 
the number of suspension fabrics is several, for example, two to three, 
and these suspension fabrics are arranged side-by-side in a direction of 
short side of the main body (1) of the air bag. In this way, if a 
plurality of suspension fabrics are arranged, the effect of holding the 
shape of the main body (1) of air bag can be improved. 
It may be applied that the suspension fabric (2) is of a cross-shape, each 
of the small sub-air chambers (4) is independently arranged and the 
through-pass holes (9) are provided at each of the suspension fabrics (2). 
An improvement in the suspension fabric (2) will be described with 
reference to FIGS. 46 to 53, in which an inversion preventive fabric (10) 
is arranged between the suspension fabrics (2). FIGS. 46 to 48 show the 
state wherein the inversion preventive fabric (10) is joined at the side 
of the upper suspension fabric (2a). FIGS. 49 and 50 show the state 
wherein the one is held and joined between the upper suspension fabric 
(2a) and the lower suspension fabric (2b). FIG. 51 shows the state wherein 
one end of the inversion preventive fabric (10) is bended and fixed to the 
central portion of the suspension fabric (2). FIG. 52 shows the state 
wherein the suspension fabric (2) is in the form of a tube, and FIG. 53 
shows the basic one of the present invention. FIGS. 54 to 58 illustrate 
the invention with a further improved tubular suspension fabric (2), and 
FIG. 59 shows the basic invention to supplement said illustration. The 
tubular suspension cloth (2) shown in FIG. 59 is operated such that when 
the main body (1) of the air bag is expanded, it is expanded with the 
front and rear surfaces curved outwardly and both front and rear surfaces 
in the circumferential surfaces of the main body (1) are rounded, and 
therefore, the tubular suspension fabric (2) is not evenly tensioned over 
the full length thereof to create shrinkages as shown in the 
circumferential surface of the suspension fabric (2). The shrunk portions 
of the suspension fabric (2) are inverted with variation of tension 
applied to the suspension fabric (2), thus posing a disadvantage in that 
there gives out a large hollow sound. However, such a hollow sound has 
been eliminated to produce by the provision of inversion preventive holes 
(11) as shown in FIGS. 54 to 58. 
While sheets of thermoplastic soft urethane resin have been principally 
used as material used in the basic invention, it is noted that material 
used in the present invention is not limited thereto but tarpaulin as 
shown in the second invention may well be used to further increase the 
effect. The tarpaulin material will be described in detail. The main body 
(1) of the air bag shown in FIGS. 34 and 35 uses a tarpaulin material (T) 
consisting of three layers, namely, thermoplastic synthetic resin sheets 
provided on the front and rear surfaces and a fabric (1c) sandwiched 
between said sheets. This thermoplastic resin sheet comprises, for 
example, a thermoplastic soft urethane resin sheet, and the fabric (1c) 
comprises nylon or those having a high tension of polyesters. 
In forming the tarpaulin material (T) as shown in FIG. 37, urethane resin 
sheets are placed on both surfaces of the fabric (1c) with the latter 
sandwiched therebetween, and the circumferential edges of these three 
elements are melted and adhered together with a desired width to form a 
three-layer sheet-like construction. 
In forming the main body (1) of the air bag, two tarpaulin sheets (T) are 
overlapped to each other, the suspension fabric (2) also comprising the 
tarpaulin material (T) is melted and adhered to the overlapped surface, 
and thereafter the circumferential edges are again thermally melted and 
adhered together. 
While the aforementioned main body (1) of the air bag has been formed by 
the tarpaulin material (T) whose peripheries are thermally melted and 
adhered, it is noted that the main body (1) of the air bag may be formed 
by overlapping two fabrics (1c) and four urethane resin sheets in the 
desired order, and thermally melting and adhering the circumferential 
edges at a time. 
The main body (1) of the air bag shown in FIG. 38 is formed of the 
tarpaulin material (T) as shown in FIGS. 40 and 41 in the manner similar 
to that of the main body (1) of the air bag. 
The main body (1) of the air bag shown in FIGS. 42 and 43 is formed of the 
tarpaulin material (T) as shown in FIGS. 44 and 45 in the manner similar 
to that of the main body (1) of the air bag as described above. 
The aforesaid tarpaulin material (T) is formed by overlapping the fabric 
(1c) cut into a planar rectangular shape and both front and rear urethane 
resin sheets, sewing the circumferential edges of these three elements 
together as shown in FIG. 44, thereafter coating the surfaces of the seam 
allowance with coating sheets comprising thermoplastic synthetic resin 
such as thermoplastic soft urethane resin, and thermally melting and 
adhering the coating sheets and the seam allowance of the both front and 
rear sheets to keep air-tightness thereof. 
The tarpaulin material (T) taken in the best form has the sectional 
construction as shown in FIGS. 68 and 69. More accurately, the fabric 
formed from yarns having coarseness of 50 to 100 microns provided with a 
non-expanding and high tensile properties and having the number of meshes 
of 70 to 200 is sandwiched between two thermoplastic synthetic resin 
sheets, and both the sheets are wholly thermally melted and adhered. 
The embodiment of the third invention will be described with reference to 
FIGS. 75 to 77, in which an urethane foam (U) is inserted into the main 
body (1) of the air bag having the suspension fabric (2) to constitute an 
air support for chair. If the urethane foam (U) has the same effect as 
that of the suspension fabric (2), the suspension fabric is not always 
required. The first example of mixture of the urethane foam (U) is as 
follows. 
The reaction temperature of the urethane foam is approximately 60.degree. 
C. to 70.degree. C., and the density thereof is 50 kg/m.sup.3 and hardness 
is 20 kg. 
Then, the invention for utilizing an air support for chair relating to the 
present invention shall be explained. One or suitable number of the air 
support for chair provided with an air feed and discharge port (3) 
connected to a pump not shown in Figures is or are enclosed airtightly in 
a seat cushion (A) or seat bag (B), as shown in FIG. 23 and FIG. 24. Air 
is supplied from the pump through the air feed and discharge port (3) to 
the seat cushion (A) or seat bag (B) under such airtightly enclosed state 
until desired cushion feeling is obtained and the air is discharged when 
this air support is not in use. 
The method for manufacturing a chair utilizing this air support is such 
that a forming mold is composed of the upper mold (C) and the lower mold 
(D) as shown in FIG. 25, FIG. 26 and FIG. 27, and the air feed and 
discharge port (3) of the air support for chair is set outside the mold as 
well as air support (E) for chair is enclosed in the central area between 
the upper mold and the lower mold in floating state. 
The expandable and retractable foam material (F), for example, urethane 
under this condition will be described. 
______________________________________ 
1. Compound of urethane 
Polyol 100 
Isocyanate 40 to 50 
Zinc oxide: heat-resistant stabilizer for 
polyvinyl chloride, foaming 
assistant 
Water + tertiary amine 3 to 4: 
foaming agent 
Foaming regulating agent of 
1 to 2 
silicon 
Catalyst of tin 0.2 to 0.4 
______________________________________ 
The above-mentioned expandable and retractable foaming material is poured 
into the mold, an entire circumference of the air support (E) for chair is 
covered with the prior expandable and retractable foaming material, 
thereafter foamed and cured to form the air support. Physical quality of 
the exapandable and retractable foaming material is as follows. 
______________________________________ 
Note 
______________________________________ 
1. Apparent density (ASTM) 
52.3 kg/m.sup.3 
2. Hardness (JIS 50 m/mt) 
Product 69 m/mt 
Load at a flexing of 25% 
16.8 kg/314 cm.sup.2 
Load at a flexing of 65% 
65 kg/314 cm.sup.2 
3. Tensile strength (JIS) 
1.23 kg/cm.sup.2 
4. Rate of elongation (JIS) 
145% 
5. Tensile strength (ASTM) 
0.97 kg/cm.sup.2 
6. Repletion resiliency (JIS) 
32.1% 
7. Compression residual degree (JIS) 
3.9% 
8. Repetitive compression residual 
3.4% 
degree 
______________________________________ 
In case that the air support (E) for the chair is independently applied in 
the seat cushion (A) or seat back (B) of the seat, as shown in FIGS. 28 
and 29, the air support (E) for the chair is placed at a proper location 
of the seat cushion (A) or the seat back (B), the pipe part of the air 
feeding and discharging port (3) is passed through the seat cushion (A) or 
the seat back (B) and connected to a pump (not shown) to perform the 
feeding and discharging of air. 
The invention of another method for manufacturing a chair using an air 
support will be described. FIG. 71 shows a conventional mold for a chair, 
FIG. 72 shows a mold with a cover opened, and FIGS. 73 and 74 are 
respectively sectional views of a mold used in the method according to the 
present invention. FIG. 70 shows a seat bag for a chair finished by said 
method, which method can be used to manufacture a seat cushion. The 
characterizing portions will be described in the following. An air support 
(E) is incorporated in advance into a lower mold (D) as shown in FIG. 73 
for molding. In this case, a portion where the air support (E) for chair 
is set in the lower mold (D) is raised as shown in FIG. 74 to form a seat 
back (B). This idea is applied to mold the seat cushion (A). A supporting 
frame (G) is set within the mold, after which the expandable and 
retractable foaming material (F) may be poured therein. One example of the 
expandable and retractable foaming material (F) is shown in the following. 
The reaction temperature is approximately 180.degree. C., the density is 35 
kg/m.sup.3 and the hardness is 15 kg. 
The seventh invention will now be described with reference to FIGS. 60 to 
69. 
FIG. 60 shows a vehicle seat provided with a support device, in which a 
seat cushion (A), a seat back (B) and a head rest (d.sub.3) are integrally 
provided, and said seat back (B) may be swung forwardly and backwardly 
from the connection with the seat cushion (A). A supporting frame (G) 
which forms a skelton of the seat cushion (A) and the seat back (B) is 
formed from a pipe and a steel plate and is covered with the expandable 
and retractable foaming material (F) of the desired wall-thickness and a 
trim cover (104) as shown in FIGS. 61 to 63. 
The support device comprises expandable and retractable members (b.sub.1), 
(b.sub.2), (b.sub.3), (b.sub.4) and (b.sub.5) which are mounted on and 
secured to the desired locations in the seat supporting frame (G) and are 
expanded and retracted by supplying and discharging air fed from an air 
pump (a) which will be described later, support plates (e.sub.1), 
(e.sub.2), (e.sub.3), (e.sub.4) and (e.sub.5) which are connected to the 
expandable and retractable members (b.sub.1) to (b.sub.5), respectively, 
directly or through the operating mechanism and provided along the desired 
parts of the rear surface of the expandable and retractable foaming 
material (F), and an air pump (a) for supplying air to the expandable and 
retractable members (b.sub.1) to (b.sub.5). 
The expandable and retractable members (b.sub.1) to (b.sub.5) are mounted 
on and secured to the desired locations of the seat supporting frame (G). 
An air pipe (37) from the air pump (a) is branched into several pipes 
through a branch valve (36), and these branched pipes (37') are connected 
to the expandable and retractable members (b.sub.1) to (b.sub.5), 
respectively, whereby air from the air pump (a) is branched by the branch 
valve (36) to feed air to the suitable expandable and retractable members 
(b.sub.1) to (b.sub.5). 
The support plates (e.sub.1) to (e.sub.5) are provided to support the 
desired parts of the human body as mentioned above, the support plate 
(e.sub.1) being disposed on a portion corresponding to a femoral portion 
in the seat surface of the seat cushion (A), the support plate (e.sub.2) 
disposed on a portion corresponding to the back of the back rest surface 
of the seat back (B), the support plates (e.sub.3) and (e.sub.4) disposed 
on both sides of thighs of the seat surface and both sides of the waist of 
the back rest surface, and the support plate (e.sub.5) disposed on the 
surface of the head rest portion (d.sub.3). Portions where the support 
plates (e.sub.1) to (e.sub.5) in the seat surface are disposed are called 
the thigh support (31), the lumbar support (32), the side supports (33) 
(34') and the head support (35), respectively. 
The expandable and retractable members (b.sub.1) to (b.sub.5) and the 
support plates (e.sub.1) to (e.sub.5) are selected in their construction, 
surface shape and operation according to the regions of the human body 
which are to be supported. However, a plurality of the main bodies (1) of 
the air bag are placed one above another to constitute the expandable and 
retractable members (b.sub.1) to (b.sub.5), the support plates (e.sub.1) 
to (e.sub.5) are connected to the expandable and retractable members 
(b.sub.1) to (b.sub.5), and air fed from the air pump (a) are supplied to 
and discharged from the expandable and retractable members (b.sub.1) to 
(b.sub.5) to move the support plates (e.sub.1) to (e.sub.5) connected to 
the expandable and retractable members (b.sub.1) to (b.sub.5) to and from 
the seat surface. 
The expandable and retractable members (b.sub.1) to (b.sub.5) are formed of 
the three-layer tarpaulin material (T) as shown in FIG. 69. This tarpaulin 
material (T) is formed by sandwiching the fabric (1c), which is woven with 
yarns having a coarseness of 50 to 100 microns provided with the 
non-expandable and retractable properties and high tensile strength and 
the number of meshes of 70 to 200 between two thermoplastic synthetic 
resin sheets (g2) and (g2), and wholly thermally melting and adhering both 
the thermoplastic synthetic resin sheets (g2) (g2) together to provide an 
integral structure of three elements (1c), (g2) and (g2). Yarns for 
constituting the fabric (1c) comprise, for example, such as polyester or 
polyamide, and the thermoplastic synthetic resin sheets (g2) (g2) comprise 
thermoplastic soft urethane resin which is somewhat harder than normal 
resin. 
The tarpaulin material (T) thus constructed is possible to prevent 
elongation by the fabric (1c) and restrain the wall-thickness of the 
material (T) itself to a degree that the flexibility of the material (T) 
is not impaired. 
However, the main body (1) of the air bag formed by use of the tarpaulin 
material (T) is less deformed when the high pressure is applied into the 
air chamber (h) and free from shrinkages resulting from the short in 
flexibility when expanded. 
The expandable and retractable member (b.sub.1) of the thigh support (31) 
and the support plate (e.sub.1) are internally provided at the foremost 
portion of the seat surface. 
The expandable and retractable member (b.sub.1) of the thigh support (31) 
is used so that the tarpaulin material (T) is cut into a generally 
rectangular shape as shown in FIG. 68, two sheets of such material (T) are 
placed one above the other, and the circumferential edges thereof are 
thermally melted and adhered together as shown in FIGS. 64 and 65 to form 
the main body (1) of the air bag. These main bodies (1) of the air bags 
are placed one above the other, and the central portion of the contact 
surface therebetween is thermally melted to join both the main bodies (1) 
of the air bags together, and air through-pass holes (i.sub.1) (i.sub.1) 
to communicate the air chambers (h.sub.1) (h.sub.1 ') of both the main 
bodies (1) of the air bags are bored in the region of the joined location. 
Mounting lugs (38) (38) are projected from both end edges of the main body 
(1) of the air bag underside of the expandable and retractable member 
(b.sub.1), supporting lugs (39) (39) similar to the mounting lugs (38) 
(38) are projected from both end edges of the main body (1) of the air bag 
on the upper side, an air port (40) for moving air in and out of the air 
chamber (h.sub.1) of the main body (1) of the air bag is provided in the 
circumferential edge of the main body (1) of the air bag, and an air pipe 
(37') branched from the branch pipe (30) is connected to the air port (40) 
through a connecting pipe (28). 
The mounting lugs (38) (38) serve to fixedly mount the expandable and 
retractable member (b.sub.1) on the supporting frame (G) in a manner such 
that the lugs (38) (38) are secured by means of fixing fittings (12) or 
screws to a base plate (41) mounted in the neighbourhood of the front end 
in the desired location of the supporting frame (G). 
The supporting lugs (39) (39) of the main body (1) of the air bag serve to 
connect the support plate (e.sub.1) to the surface of the main body (1) of 
the air bag and support the same and is fixed to the neighbourhood of the 
both ends of the rear face of the support plate (e.sub.1) by fixing 
fittings (12) or by adhesion. 
The support plate (e.sub.1) is formed of synthetic resin or steel plate, 
and the surface thereof is adjusted to the surface of the femoral portion 
in the seat surface to form a natural curve. In the normal condition, the 
surface of the support plate (e.sub.1) is applied to the rear surface of 
the expandable and retractable foaming material (F) of the thigh support 
(31) portion. 
When the air is supplied from the air port (40) of the main body (1) of the 
air bag, the air passes through the air through-pass holes (i.sub.1) 
(i.sub.1) from the air chamber (h.sub.1) and flows into the air chamber 
(h.sub.1 ') of the main body (1) of the air bag to expand the main body 
(1) of the air bag to expand the expandable and retractable member 
(b.sub.1) itself. Thereby, the support plate (e.sub.1) connected to the 
surface of the expandable and retractable member (b.sub.1) extends toward 
the seat surface and the thigh support (31) portion of said seat surface 
inflates according to the expansion of the expandable and retractable 
member (b.sub.1). 
The expandable and retractable members (b.sub.3) (b.sub.3) of the side 
support (33) on both sides of the femoral portion have the construction as 
shown in FIGS. 62 and 67. 
The expandable and retractable member (b.sub.3) is constructed such that 
the tarpaulin materials (T) cut into a rectangular shape are placed one 
above the other, the main body (1) of the air bag whose circumferential 
edges are thermally melted and adhered is superimposed, the portion along 
one side edge on the longer side in the contacted surface therebetween is 
thermally melted and adhered to join both the main bodies (1) of the air 
bags together, and air through-pass holes (i.sub.3) (i.sub.3) to provide 
communication between the air chambers (h.sub.3) (h.sub.3 ') of the main 
body (1) of the air bag are bored in the area of said joined portion. 
The expandable and retractable members (b.sub.3) (b.sub.3) are mounted on 
the surface of base plates (13) (13), respectively, stood upright while 
being somewhat inclined from both sides of the supporting frame (G) toward 
the upper portion with the joined side directed downwardly. The mounting 
lug (14) (14) projected on one side edge of the main body (1) of the air 
bag of the expandable and retractable members (b.sub.3) (b.sub.3) are 
secured to the surfaces of the base plates (13) (13) by means of screws 
(15) and fixedly mounted on the surfaces of the base plates (13) (13). 
The support plate (e.sub.3) adjusted to the surface of the side support 
(33) of the seat surface is applied to the surface of the expandable and 
retractable members (b.sub.3) (b.sub.3), and the supporting lugs (16) (16) 
projected on both end edges of the main body (1) of the air bag are 
secured to the rear surface of the support plate (e.sub.3) by means of 
fixing fittings (12) to thereby connect the support plate (e.sub.3) to the 
surfaces of the expandable and retractable members (b.sub.3) (b.sub.3). 
The support plate (e.sub.3) connected to the surfaces of the expandable 
and retractable members (b.sub.3) (b.sub.3) has its surface provided along 
the rear surface of the expandable and retractable foaming material (F) of 
the side support (33) portion. 
An air pipe (37') branched from the branch valve (36) is connected through 
a connecting pipe (28) to the air port (3) provided in one side edge of 
the main body (1) of the air bag. 
Since the expandable and retractable members (b.sub.3) (b.sub.3) is 
constructed such that portions along one side edge of the main body (1) of 
the air bag are joined, when air is supplied to the expandable and 
retractable members (b.sub.3) (b.sub.3) to expand the main body (1) of the 
air bag, other side edges of the expandable and retractable members 
(b.sub.3) (b.sub.3) are opened and stretched so as to form a generally 
V-shape in section as shown in FIG. 62 whereby the support plate (e.sub.3) 
connected to the surfaces of the expandable and retractable members 
(b.sub.3) (b.sub.3) is projected so as to increase an angle of inclination 
toward the central portion of the seat surface and inflate the surface of 
the side support (33) as well. 
As shown in FIG. 61, the support plate (e.sub.4) of the side support (34) o 
the side of the seat back (B) is connected to the expandable and 
retractable members (b.sub.4) (b.sub.4) through an operating mechanism 
(j). 
The operating mechanism (j) is constructed such that a support shaft (18) 
is mounted between shaft carriers (20) (20) erected toward the central 
portion of the seat from bearing plates (19) (19) on both sides of the 
supporting shaft (G), and an arm plate (21) is pivotally supported by the 
support shaft (18). The support plate (e.sub.4) adjusted to the curved 
surface of the side support (34) is fixedly mounted on the inner side at 
the extreme end of the arm plate (21) in the state wherein the support 
plate (e.sub.4) is applied to the rear surface of the expandable and 
retractable foaming material (F) of the side supports (34) (34). 
Furthermore, the expandable and retractable members (b.sub.4) (b.sub.4) are 
placed between the rear end of the arm plate (21) and the fixed surfaces 
(22a) (22a) of fixing members (22) (22) projected in the shape of L from 
the bearing plates (19) (19) toward the central portion of the seat, the 
mounting lugs (23) (23) projected from both ends of the main body (1) of 
the air bag on the sides of the fixed surfaces (22a) (22a) are secured to 
the fixed surfaces (22a) (22a) by means of fittings (12), and the 
supporting lug (19) projected from both ends of the main body (1) of the 
air bag on the side of the arm plate (21) is secured to the rear surface 
of the support plate by means of the fittings (12). 
The expandable and retractable members (b.sub.4) (b.sub.4) are constructed 
such that three air-bag main bodies (1) are placed one above another, the 
central portions in the contacted surface of the main bodies (1) are 
thermally melted and adhered to join each of the main bodies (1) of the 
air bags together, air through-pass holes (i.sub.4) (i.sub.4) to provide a 
communication between the air chambers (h.sub.4) (h.sub.4 ') and (h.sub.4 
") of the main body (1) of the air bag are bored in the area of the joined 
location, an air port (24) is formed in the main body (1) of the air bag 
on the side of the fixed surface (22a), and an air pipe (37') branched 
from the branch valve (36) is connected to the air port (24) through a 
connecting pipe (28). 
When air is supplied to the expandable and retractable members (b.sub.4) 
(b.sub.4) of the side support (34) to expand each of the main bodies (1) 
of the air bags and expand the expandable and retractable members 
(b.sub.4) (b.sub.4), the rear end of the arm plate (21) is urged outwardly 
to turn the arm plate (21). Then, the support plate (e.sub.4) provided at 
the extreme end of the arm plate (21) pivots around the support shaft (18) 
toward the central portion of the seat to thereby inflate the surface of 
the side support (34). 
The expandable and retractable member (b.sub.2) and support plate (e.sub.2) 
in the lumbar support (32) have the same construction as the expandable 
and retractable member (b.sub.1) and support plate (e.sub.1) in the thigh 
support (31), wherein as shown in FIG. 60, the expandable and retractable 
member (b.sub.2) composed of two main bodies (1) of the air bags is 
fixedly mounted on the back rest base plate (25) provided between both 
bearing plates (19) (19) of the supporting frame (G), the support plate 
(e.sub.2) adjusted to the curved surface of the lumbar support (32) is 
connected to the surface of the expandable and retractable member 
(b.sub.2) by means of screws or fittings (12), whereby air is supplied 
from the air through-pass hole (26) into the expandable and retractable 
member (b.sub.2) to expand the expandable and retractable member (b.sub.2) 
and project the support plate (e.sub.2) toward the surface of the lumbar 
support (32) thereby inflating the surface of the lumbar support (32). 
Also, the expandable member (b.sub.5) and support plate (e.sub.5) of the 
head support (35) have the same construction as the expandable and 
retractable members (b.sub.1) (b.sub.2) and support plates (e.sub.1) 
(e.sub.2) of the thigh support (31) and lumbar support (32) except that in 
the expandable and retractable member (b.sub.5) of the head support (35), 
both longitudinal and lateral widths of the main body (1) of the air bag 
are widened so as to avoid deflections in all directions of the main 
bodies (1) of the air bags when supported, and the area of the joined 
surface of both the main bodies (1) of the air bags is formed into a wide 
square shape. 
The support plate (e.sub.5) is also formed largely and curved along the 
back of the head naturally, and when air is supplied into the expandable 
and retractable member (b.sub.5) to inflate the surface of the head 
support (35), the back of the head of the user may be positively supported 
without deflection. 
The branch valve (36) for distributing air fed from the air pump (a) to the 
expandable and retractable members (b.sub.1) to (b.sub.5) of the support 
portions (31) to (35), respectively, is provided with five branch flow 
passages (not shown) adapted to branch air through-pass passages (not 
shown) in communication with the air pump (a) through an air pipe (37), 
said branch flow passages each being provided with a three-way valve (not 
shown) adapted to open and close the flow passage to discharge air in said 
flow passage outside. The opening and closing and discharging operations 
of the three-way valve are made by operating buttons (k.sub.1) to 
(k.sub.5). When the desired one of the support portions (31) to (35) is 
inflated, the operating buttons (k.sub.1) to (k.sub.5) of the support 
portions (31) to (35) are set to their open position to supply the air fed 
from the air pump (a) to the expandable and retractable members (b.sub.1) 
to (b.sub.5) of the support portions passing through the air pipes (37') 
connected to the branch passages, respectively. 
When the suitable support surface is inflated and supported in the desired 
state, the operating buttons (k.sub.1) to (k.sub.5) of the support 
portions are moved to their closed position to stop a supply of air. 
When the support of the desired supports (31) to (35) portions are loosened 
or depressed so as to face to the surface of the other seat in the 
original state, the operating buttons (k.sub.1) to (k.sub.5) of the 
support portions are moved to the discharging position, and air within the 
expandable and retractable members (b.sub.1) to (b.sub.5) of the support 
portions is discharged outside from the branch passages in communication 
with the expandable and retractable members (b.sub.1) to (b.sub.5). 
The branch valve (36) is located on the side of the air cushion (A) so that 
the user may access thereto along with the operating switch (27) and the 
like. 
While in the above-mentioned air support device, seven sets of the 
expandable and retractable members (b) and support plates (e) have been 
used, it is to be noted that more than one set of the expandable and 
retractable members (b) and support plates (e) could be used as desired 
and also their installing locations could be optional as long as they are 
located on the seat surface. However, in the case where plural sets of the 
expandable and retractable members (b) and support plates (e) are 
provided, air from the air pump (a) need be supplied to the suitable 
expandable and retractable member (b), and therefore, the branch valve 
(36) used in the air support device is required. 
For connecting the support plate (e) to the expandable and retractable 
member (b), it may be directly connected to the surface of the expandable 
and retractable member (b) as in the supports (31), (32), (33) and (35) of 
the support device or may be connected through the operating mechanism (j) 
as in the side support (34), which can be selected according to the need 
of design.