Air support for chair and method for manufacturing chair utilizing the air support

An inflatable support device for use in a chair includes two flexible, generally rectangular outer elements which are sealingly connected along corresponding peripheral edge portions, a plurality of parallel connection elements positioned between and connected to the rectangular outer elements and shaped so as to cause one of the outer elements to have a sinusoidal configuration when the support device is filled with air, and an air port connected to one of the rectangular outer elements.

DETAILED DESCRIPTION OF THE INVENTION 
This invention related to an air support for chair, and more particularly 
an improvement of the air support to be used in an automobile and the 
improved air support has some devises in its utilization and manufacturing 
aspect. 
This kind of conventional air support is a mere air bag and it is a major 
trend to use this air bag into which air is fed 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 above-mentioned disadvantages of the 
prior art are eliminated for its object. 
Referring now to the drawings, some preferred embodiments of the present 
invention will be described.

EMBODIMENT 
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 planer 
rectangular shape by overlaying 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 amin body (1) is maintained 
in a unitary form without being partitioned by the suspension fabric (2). 
The suspension fabric (2) could be used in its tubular form. Further, 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 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. 
Further, in the first preferred embodiment, the suspension fabric is 
applied as one fabric and 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 amin 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 amin 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 bot 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 amin 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 arrangment, 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 pum (not shown) at its rear 
surface. 
The suspension fabrics (2) are of the same material quality as that of the 
amin 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 
width of the abovementioned 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 sub-chambers (7) arranged along the concave 
poritons 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 upto 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 planer rectangular shape, and one of the sheet 
surfaces (1a) and (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 or 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 
extened 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 described in 
reference to the drawings. 
The main body (1) of the air bag is constructed such that as shown in FIG. 
16, 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 planer 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 upper-most part and the 
lower-most 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 (FIG. 17). 
As described above, in order to fix the upper-most part and the lower-most 
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 the drawings. 
As shown in FIG. 19, the suspension fabric (2) is inserted and fitted to a 
rod-like lower electrode (C.sub.1), a rear sheet (a) is placed on the 
suspension fabric (2) to set its position, then an upper electrode 
(C.sub.2) is forcedly contacted onto the rear sheet (a) to hold the 
upper-most part of the suspension fabric (2) and the rear sheet (a) 
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) (FIG. 
20), and both the suspension fabric (2) and the rear sheet (a) are held by 
both electrodes (C.sub.1) and (C.sub.2), thereafter they are thermally 
melted and adhered (FIG. 21). 
As described above, the suspension fabric (2) and the rear sheet (a) 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 front sheet (b) 
in the same manner as that of the rear sheet (a), and then the suspension 
fabric (2) is applied over both sheets (a) and (b). 
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 upper-most 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 rear sheet (a) 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 front and rear sheets (a) and (b) having the suspension fabric (22) 
thermally melted and adhered form the planer 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 (4) 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 
sheets (a) and (b) 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) 
(FIG. 22). 
Both side surfaces (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 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 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 side surfaces (2a) and (2b) of the 
suspension fabric (2) 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 planer 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, 
these suspension fabrics are arranged side-by-side in a direction of short 
side of the main body 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 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. 
The air support for the chair of the present invention is made with the 
above-mentioned constitution. 
Then, the dependent inventions of the air support for the chair of the 
present invention will be described, as shown in FIGS. 23 and 24, one or a 
proper number of air supports for the chair having the air feeding and 
discharging port (3) to be connected to a pump (not shown) are sealingly 
enclosed in the seat cushion (A) or the seat-back (B). Under this sealed 
condition, air is fed from the pump through the feeding and discharging 
port (3) to cause the seat cushion (A) or the seat-back (B) to be expanded 
to make a desired feeling of cushioning and if it is not used, the air is 
extracted to make a normal flat condition. 
The method for manufacturing the air support for the chair of the present 
invention will be described, wherein as shown in FIGS. 25 and 26, and FIG. 
27, a molding die is formed by the upper mold (C) and the lower mold (D), 
the air support (E) for the chair is floated at the central parts of the 
upper mold and the lower mold and stored therein, and the feeding and 
discharging port (3) for the air support for chair is set out of the 
molds. 
The expandable and retractable foam material (F), for example, urethane 
under this condition will be described. 
1. Compound of urethane 
______________________________________ 
1. Compound of urethane 
______________________________________ 
Polyol 100 
Iocyanate 40 to 50 
Zinc oxide: heat-resistant stabilizer for 
polyvynil chloride, foaming 
assistant 
Water + tertiary amine 3 to 4: 
foaming agent 
Foaming regulating agent of silicon 
1 to 2 
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 expandable and retractable foaming material is as follows. 
______________________________________ 
Note 
______________________________________ 
1. Apparant 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 first effect of the present invention will be described. Since each of 
the suspension fabrics is arranged, the surface of the chair can form the 
proper concave part to cause the body of the sitting person to be fit 
thereto to show an effect of reducing a feeling of fatigue. Since the 
second invention is constructed to have the air support for the chair 
enclosed in the seat, it may provide an effect of reducing dropping of the 
unit and facilitating its manufacturing process. 
The third invention shows the concrete method for manufacturing the air 
support in which the air support for the chair may easily be assembled in 
the seat and can be used in it.