PNEUMATIC BLADDER ARRANGEMENT
20240217420 ยท 2024-07-04
Inventors
Cpc classification
B60N2002/899
PERFORMING OPERATIONS; TRANSPORTING
International classification
Abstract
The invention relates to a pneumatic bladder arrangement (100) for a seat (S) comprising a plurality of inflatable bladders (110), wherein at least one of the plurality of inflatable bladders (110), when inflated, has a first edge (111) with a first thickness (T1) and a second edge (112) with a second thickness (T2), wherein the first thickness (T1) is bigger than the second thickness (T2), the invention also relates to a seat (S) comprising the pneumatic bladder arrangement and to a manufacturing method for an inflatable bladder.
Claims
1. A pneumatic bladder arrangement for a seat comprising: a plurality of inflatable bladders, wherein at least one of the plurality of inflatable bladders, when inflated, has a first edge with a first thickness and a second edge with a second thickness, and wherein the first thickness is bigger than the second thickness, and wherein the at least one of the plurality of inflatable bladders includes a thickness defining element configured to limit an inflation thickness of the at least one of the plurality of inflatable bladders, and wherein the at least one of the plurality of inflatable bladders includes a first sheet of flexible material and a second sheet of flexible material, which are bound together to form the at least one of the plurality of inflatable bladders, and wherein the thickness defining element is bound to the first sheet of flexible material and to the second sheet of flexible material, and wherein the thickness defining element is bound to the first sheet of flexible material and to the second sheet of flexible material in a direction perpendicular to the first edge or to the second edge.
2. The pneumatic bladder arrangement of claim 1, wherein the at least one of the plurality of inflatable bladders, when inflated, has a wedge-like shape.
3. The pneumatic bladder arrangement of claim 1, wherein the at least one of the plurality of inflatable bladders, when inflated, has a wedge-like cross section shape.
4. The pneumatic bladder arrangement of claim 1, wherein the at least one of the plurality of inflatable bladders has a third edge and a fourth edge, wherein a first width between the third edge and the fourth edge in proximity of the first edge is larger than a second width between the third edge and the fourth edge in proximity of the second edge.
5. The pneumatic bladder arrangement of claim 1, wherein the at least one of the plurality of inflatable bladders (210) has a trapezoidal shape.
6. (canceled)
7. (canceled)
8. (canceled)
9. The pneumatic bladder arrangement of claim 1, wherein the thickness defining element is bound to the first sheet of flexible material and to the second sheet of flexible material in a longitudinal direction of the at least one of the plurality of inflatable bladders.
10. The pneumatic bladder arrangement of claim 1, wherein the thickness defining element has a third width corresponding to the first thickness and a fourth width corresponding to the second thickness.
11. The pneumatic bladder arrangement of claim 10, wherein the thickness defining element has a decreasing width between the third width and the fourth width.
12. The pneumatic bladder arrangement of claim 1, wherein the thickness defining element (330, 430) has a trapezoidal or a triangular shape.
13. The pneumatic bladder arrangement of claim 1, wherein the thickness defining element is of the same material as the first sheet of flexible material or the second sheet of flexible material.
14. The pneumatic bladder arrangement of claim 1, wherein the at least one of the plurality of inflatable bladders is a composite bladder and includes a first sub-bladder and a second sub-bladder, which are overlapped and in pneumatic communication with each other.
15. The pneumatic bladder arrangement of claim 1, wherein at least two of the plurality of inflatable bladders at least partially overlap each other.
16. The pneumatic bladder arrangement of claim 1, wherein the plurality of inflatable bladders are arranged next to each other.
17. The pneumatic bladder arrangement of claim 1, wherein one or more couples of the plurality of inflatable bladders each include a first inflatable bladder and a second inflatable bladder, and wherein the first inflatable bladder is in fluid connection with the second inflatable bladder through a fluid interconnection.
18. The pneumatic bladder arrangement of claim 1, wherein when the pneumatic bladder arrangement is mounted as shoulder support in a seat, the first edge is higher than the second edge with respect to a vertical direction of the seat.
19. The pneumatic bladder arrangement of claim 1, wherein when the pneumatic bladder arrangement is mounted as a leg support in a seat, the first edge is closer to a front extremity of a cushion of the seat than the second edge.
20. The pneumatic bladder arrangement of claim 1, wherein when the pneumatic bladder arrangement is mounted as a cushion support in a seat, the second edge is closer to a front extremity of a cushion of the seat than the first edge.
21. The pneumatic bladder arrangement of claim 1, wherein the first thickness is between 1 cm and 15 cm, and wherein the second thickness is between 1 cm and 12 cm.
22. The pneumatic bladder arrangement of claim 1, wherein the plurality of inflatable bladders includes an odd number of bladders.
23. The pneumatic bladder arrangement of claim 1, further comprising a seat having the pneumatic bladder arrangement.
24. The pneumatic bladder arrangement of claim 23, wherein the seat includes a non-stretchable trim and a stretchable trim, wherein the stretchable trim is provided so as to allow inflating of the pneumatic bladder arrangement.
25. The pneumatic bladder arrangement of claim 24, wherein the stretchable trim is provided at least in a part of the seat closer to the first edge than to the second edge.
26. A method for manufacturing an inflatable bladder for a pneumatic bladder arrangement for a seat, the method comprising: providing a first sheet of flexible material, a second sheet of flexible material and a thickness defining element, bonding the first sheet of flexible material to the thickness defining element, bonding the second sheet of flexible material to the thickness defining element, and bonding the first sheet of flexible material to the second sheet of flexible material.
27. The method of claim 26, further comprising bending the thickness defining element.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0060]
[0061]
[0062]
[0063]
[0064]
[0065]
[0066]
[0067]
[0068]
[0069]
[0070]
[0071]
[0072]
[0073]
[0074]
[0075]
[0076]
[0077]
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0078]
[0079] For explanation purposes, the seat S will be illustrated as the seat of a vehicle, preferably of a car. It will however be clear that the invention is not limited thereto and it can be applied to any seat. Application to a vehicle seat is particularly advantageous as the invention, compared to the prior art, achieves a low weight and a high degree of adaptation of the seat to the body of the occupant, both of which are criteria which are generally requested and appreciated in vehicle seats. Moreover, the invention drastically reduces the number of parts which might pose a risk in a collision. To the contrary, by introducing pneumatic bladders, it might even form a passive safety device in case of a collision. Both those features are highly appreciated in vehicle seats.
[0080] In the illustration of
[0081] Reverting to
[0082] In the following, a more specific description of one of the bladders will be provided. While reference is made to a single bladder, this is understood to possibly apply to more than one bladder of the plurality of bladders of the pneumatic bladder arrangement. Preferably, this might apply to a majority of the plurality of bladders of the pneumatic bladder arrangement, still more preferably to each of the plurality of bladders of the pneumatic bladder arrangement.
[0083] As visible in
[0084] Throughout the description, the expression when inflated relates to an inflation of at least 30%, preferably at least 60%, even more preferably at least 90%.
[0085] In preferred embodiments, the first thickness T1 is preferably comprised between 1 cm and 15 cm, even more preferably between 2 cm and 8 cm. Alternatively, or in addition, the second thickness T2 is preferably comprised between 1 cm and 12 cm, preferably between 1 cm and 5 cm.
[0086] In some embodiments, the first thickness T1 can correspond to a thickness of the thickest portion of the bladder. Alternatively, or in addition, the second thickness T2 can correspond to a thickness of the thinnest portion of the bladder
[0087] Alternatively, or in addition, the first and second thickness can be measured at the respective edge of the bladder. In some embodiments, the term edge can understood to be an outmost extremity of the bladder. Alternatively, or in addition, the edge can comprise a region within 15%, preferably 10%, even more preferably 5% of the length of the bladder starting from a respective outmost extremity of the bladder. In this latter case, in some embodiments, the first and/or second thickness can be measured at the thickest part of the bladder in the respective region.
[0088] In general, the bladder has a shape elongated along a given direction. In the example of
[0089] The difference between the thickness T1 and T2 results in the inflatable bladder generally having a wedge-like shape, when inflated. Preferably, the inflatable bladder, when inflated, has a wedge-like cross section shape and/or a wedge-like shape when seen from the side. In some embodiments the cross section is intended as being taken along a cross section plane defined by the length and thickness of the bladder.
[0090] Similarly, the side is intended as a view from a direction perpendicular to such cross section plane.
[0091] The wedge-like shape, in some embodiments, can be a shape in which the inflatable bladder, when inflated, has a cross section in which the two longest sides are substantially linear and not parallel, converging toward each other from the first edge 111 toward the second edge 112. Alternatively, or in addition, in some embodiments the wedge-like shape can be a shape in which the inflatable bladder, when inflated, has a cross section, taken along a plane perpendicular to its longitudinal direction, which monotonically decreases for a at least one region comprised between the first edge 111 and the second edge 112, when moving from the first edge 111 toward the second edge 112. Preferably, this cross section can monotonically decrease from the first edge 111 to the second edge 112. Preferably, in some embodiments, in addition to be monotonically decreasing the cross section can also gradually decrease.
[0092] This is for instance clearly visible in the cross section view on the right side of
[0093] In a preferred application, illustrated in
[0094] In other words, with reference to the vertical direction Y indicated in
[0095] This has the advantage that, when inflated, the top portion of the pneumatic bladder arrangement 100 has a bigger thickness than the bottom portion of the pneumatic bladder arrangement 100. This is particularly advantageous as it conforms better to the shape of the shoulder of an occupant, as well as avoiding a step being created between the second edge and the part of the backrest below it.
[0096] In an alternative preferred application, illustrated in
[0097] In other words, the pneumatic bladder arrangement 1000 can be mounted so that the first edge 111 is further away from the backrest of the seat S than the second edge 112. Even more preferably, the first edge 111 can be positioned substantially in correspondence with the front edge of the cushion C, namely the edge of the cushion C opposite the backrest.
[0098] This has the advantage that, when inflated, the front portion of the pneumatic bladder arrangement 1000 has a bigger thickness than the rear portion of the pneumatic bladder arrangement 1000, front and rear referring to the orientation of the seat S. This is particularly advantageous as it conforms better to the shape of the thighs of an occupant, particularly of a tall occupant, as well as avoiding a step being created between the second edge and the part of the cushion behind it, toward the backrest.
[0099] In yet an alternative preferred application, illustrated in
[0100] In other words, the pneumatic bladder arrangement 1100 can be mounted so that the second edge 112 is further away from the backrest of the seat S than the first edge 111. Even more preferably, the second edge 112 can be positioned substantially in correspondence with the rear edge of the cushion C, namely the edge of the cushion C closest to the backrest.
[0101] This has the advantage that, when inflated, the rear portion of the pneumatic bladder arrangement 1100 has a bigger thickness than the front portion of the pneumatic bladder arrangement 1100, front and rear referring to the orientation of the seat S. This is particularly advantageous as it conforms better to the shape of the buttocks of an occupant, as well as avoiding a step being created between the second edge and the part of the cushion in front of it, away from the backrest.
[0102] This is further particular advantageous since, in most foldable seats S, when the backrest is extended toward a flatter configuration, most often a step, or a gap, is generated between the rear edge of the cushion and the bottom edge of the backrest. The possibility to inflate the pneumatic bladder arrangement 1100 in a wedge shape allows such step, or gap, to be compensated so that an occupant can lie on the extended seat without feeling such step, or gap, which would be generally perceived as being uncomfortable.
[0103] It will be clear that the above are exemplary applications of the pneumatic bladder arrangement and are not intended to limit the invention.
[0104] In the above description, reference has been made to a bladder as having a wedge-like shape, when seen from the side or in a cross section. In the following, various possible manners for obtaining such a shape in an inflatable bladder will be described.
[0105]
[0106] In particular, the bladder 210 has a third edge 213 and a fourth edge 214, wherein a first width W1 between the third edge 213 and the fourth edge 214 in proximity of the first edge 211 is larger than a second width W2 between the third edge 213 and the fourth edge 214 in proximity of the second edge 212.
[0107] In some embodiments, the third edge 213 and the fourth edge 214 can be edges connecting the first edge 111, 211 and the second edge 112, 212. This results in the bladder 210 having a substantially quadrilateral shape, preferably, a trapezoidal-like shape.
[0108] This shape is particularly recognizable in the top view, on the left of
[0109] Thanks to such trapezoidal-like shape in the top view, the bladder automatically inflates to a wedge-like shape. In fact, as the width between the third edge 213 and the fourth edge 214 decreases, so does the cross section of the bladder taken on a plane perpendicular to its length. This reduction in cross section results in a lower thickness of the bladder and thus allows the wedge-like shape to be formed.
[0110] In the case of such trapezoidal-like shape in the top view, in some embodiments, the elongation or longitudinal direction of the bladder can be understood to mean a direction bisecting an angle defined by edges 213 and 214.
[0111]
[0112] In particular, the bladder 310 comprises a thickness defining element 330 configured to limit an inflation thickness of the bladder 310. In some embodiments, the thickness defining element 330 can be implemented as a sheet of material being placed along a plane substantially aligned with the longitudinal direction of the bladder and with the inflating direction of the bladder. Preferably, as visible on the left side of
[0113] The thickness defining element 330 generally limits the inflation thickness which can be achieved at one or more regions of the bladder. Thus, by configuring the thickness defining element 330, the thickness of such one or more regions can be defined, so as to obtain the wedge-like shape.
[0114] In some embodiments, the bladder 210, 310 can in particular further comprises a first sheet of flexible material 321 and a second sheet of flexible material 322, which are bound together to form the bladder. In this case, the thickness defining element 330 can be bound to the first sheet of flexible material 321 and to the second sheet of flexible material 322. In this manner, the thickness defining element 330 limits a maximum relative distance between the first sheet of flexible material 321 and the second sheet of flexible material 322, this regulating the inflating thickness of the bladder.
[0115] In some embodiments, the thickness defining element 330 can be bound to the first sheet of flexible material 321 and to the second sheet of flexible material 322 in a direction substantially perpendicular to the first edge 111 and/or to the second edge 112. Alternatively, or in addition, the thickness defining element 330 can be bound to the first sheet of flexible material 321 and to the second sheet of flexible material 322 in a substantially longitudinal direction of the bladder.
[0116] In some embodiments, as visible in the left part of
[0117] Preferably, the thickness defining element 330 is made of the same material as the first sheet of flexible material 321 and/or the second sheet of flexible material 322. This allows a simplified manufacturing.
[0118] While the thickness defining element 330 has been illustrated in
[0119] As can be seem in
[0120] A yet alternative manner for obtaining the wedge-like shape will be discussed with reference to
[0121] In particular,
[0122] As visible in
[0123] In some embodiments the first sub-bladder 1210A and the second sub-bladder 1210B can each to be understood as being a bladder. The second sub-bladder 1210B preferably in smaller, particularly when seen in a top view, than the first sub-bladder 1210A.
[0124] The first sub-bladder 1210A and the second sub-bladder 1210B can each be implemented as previously described with two sheets of flexible material. In particular, as visible on the bottom right part of
[0125] Preferably, the second sub-bladder 1210B is positioned on the first sub-bladder 1210A closer to the first edge 111, 1211 than to the second edge 112, 1212. in this manner, the additional thickness implemented by the second sub-bladder 1210B allows to implement the difference between the first thickness T1 and the second thickness T2, thus obtaining the wedge-like shape.
[0126] Although the composite bladder has been described as comprising two sub-bladders only, the present invention is not limited thereto and it will be clear that a higher number of overlapping sub-bladders can be implemented, for instance with the aim of obtaining a more gradual decrease in thickness from T1 to T2.
[0127] Thus, as visible from the above description, various manners can be implemented for obtaining the difference in thicknesses T1 and T2 and more generally the wedge-like shape of the bladder. Those manners can be combined as needed. Moreover, not all bladders in the pneumatic bladder arrangement need to be implemented in the same manner for achieving the wedge-like shape.
[0128] In the schematic illustration of
[0129] Preferably, the combined dimension of the bladders in the X direction is substantially comprised between 30 cm and 60 cm, even more preferably between 35 cm and 50 cm. The X direction can correspond to a width direction of the seat S.
[0130] In some embodiments, one or more of the plurality of bladders, preferably a majority thereof and even more preferably each of them, can have a substantially elongated shape along an elongation direction. In
[0131] Moreover, in some embodiments, two or more bladders, preferably each of them, can have their first edge 111 oriented toward the same direction of the pneumatic bladder arrangement.
[0132] Further preferably, in some embodiments the first edge 111 of two or more bladders, preferably of each of them, can be placed substantially along a line. In the illustrated example this corresponds to direction X. In some embodiments, as illustrated in
[0133] While in
[0134] The overlapping can be particularly advantageous in increasing the wedge-like shape of the pneumatic bladder arrangement. Thus, in some embodiments, the one or more overlapping regions 740 can be at least in a region of the pneumatic bladder arrangement closer to the first edge 111 than to the second edge 112. Alternatively, or in addition, the one or more overlapping regions 740 can have a large area in a region of the pneumatic bladder arrangement closer to the first edge 111 than to the second edge 112.
[0135] The overlapping can be present when the bladders are not inflated. In addition, in some embodiments, the overlapping can also be present when the bladders are inflated.
[0136] In some embodiments the plurality of bladders can thus obtain a pneumatic bladder arrangement having a length, direction Y in the drawings, substantially corresponding to a length of a single bladder. Alternatively, or in addition, the in some embodiments the plurality of bladders can thus obtain a pneumatic bladder arrangement having a width, direction X in the drawings, substantially corresponding to the sum of the widths of the bladders.
[0137] In the above description, the bladders of the pneumatic bladder arrangement have been described without a specific indication of how they can be inflated and/or deflated as various manners for achieving this are known to the skilled person.
[0138] For instance, each bladder might be provided with a fluid supply connection, such as a pipe, to a pump and/or to a valve. This allows each bladder to be controlled independently, so as to allow the user to independently define the thickness of various regions of the pneumatic bladder arrangement.
[0139] Alternatively, or in addition, as visible for instance in
[0140] Thanks to this connection, as visible in
[0141] The lack of possibility of controlling each bladder independently is usually not a drawback, particularly if, as illustrated the bladders are connected by the fluid interconnection in a symmetrical manner with respect to an axis of symmetry of the pneumatic bladder arrangement. In some embodiments, such axis of symmetry is preferably aligned with the X direction, in the drawing, or with a longitudinal direction of one or more of the bladders. Preferably, the axis of symmetry is placed substantially in the middle of the width of the pneumatic bladder arrangement.
[0142] Thanks to this arrangement, it is thus possible to control the bladders of the pneumatic bladder arrangement which are connected through the fluid interconnections in a symmetrical manner. Usually, this is not perceived by the users as a drawback but, rather, as an appreciated feature, since symmetrical parts of the pneumatic bladder arrangement usually act on symmetrical regions of the body, for which the user expect a symmetrical inflation thickness.
[0143] The number of couples of bladders connected by a fluid interconnection 950/1, 950/2 is not limited to the two couples illustrated. In those embodiments implementing such couples, at least one couple can be present, preferably two, or at least two.
[0144] Moreover, in the embodiments implementing one or more such couples, not all bladders need to be connected in such a couple. This is illustrated, for instance, in
[0145] Preferably, in some embodiments, if some bladders are connected in couples and some are not, at least one of the bladders not connected in a couple is placed substantially in the middle of the bladder arrangement, in the width direction, as illustrated in
[0146] Thus, it has been described how the pneumatic bladder arrangements can be implemented as support in various positions of a seat. It will therefore be clear that some embodiments of the invention can also relate to a seat S comprising the pneumatic bladder arrangement. One such example is illustrated in
[0147] In particular,
[0148] In some embodiments, the seat S can comprising a trim, with the pneumatic bladder arrangement being placed under the trim, possibly with some additional elements in between, such as padding layers. In some embodiments, the trim can comprise a stretchable material, such as various kinds of fabric. In those embodiments the inflation of the pneumatic bladder arrangement can result be accommodated by the stretching of the trim. Some preferred seat trims, however, are not particularly stretchable, one example being leather. In some embodiments in which the trim comprises such non-stretchable trim, NST in
[0149] It will be clear that various shapes and/or positioning of the stretchable trim ST can achieve such result. Without limiting the invention, in some embodiments such as the one illustrated in
[0150] In several practical applications, the seat S might also comprise padding material, such as, for instance, foam. The positioning of the pneumatic bladder arrangement with respect to this padding material is not limited.
[0151] The pneumatic bladder arrangement can thus be mounted under the padding material, that is, between the seat frame and the padding material. Alternatively, or in addition, it can be mounted in between various layers of, or in a hole of, the padding material. Still alternatively, or in addition, it can be mounted over the padding material, that is, between padding material and the trim.
[0152] Each of those options, as will be clear to the skilled person, has various advantages. The mounting under the padding material, in particular, provides the advantage that the pneumatic bladder arrangement can be implemented also in seats where no space would be available between the padding material and the trim, for instance because another pneumatic bladder arrangement is positioned at that location. This can be the case, for instance, for pneumatic bladder arrangements intended for massage purposes, which are generally preferably placed closer to the trim.
[0153] In the description above, various shapes for the inflatable bladders have been described. Experts in the field of inflatable bladder manufacturing are aware of various technologies for implementing those shapes, for instance by bonding together sheets of flexible material.
[0154]
[0155] The method 500 comprises a step S510 of providing a first sheet of flexible material 321, a second sheet of flexible material 322 and a thickness defining element 330. In some embodiments, the thickness defining element 330 might also be implemented by a sheet of flexible material with characteristics similar, or identical, to those of the first sheet of flexible material 321 and/or of the second sheet of flexible material 322. While the various elements have been illustrated in
[0156] The method 500 further comprises a step S521 of bonding the first sheet of flexible material 321 to the thickness defining element 330. In the figure, such bonding is indicted by B1. Preferably, the thickness defining element 330 has an elongated shape with two longer edges, and one such longer edge can be bonded to the first sheet of flexible material 321. In some embodiments the bonding B1 is substantially in the longitudinal direction of the inflatable bladder and preferably in a middle portion thereof, in the width direction.
[0157] The method 500 further comprises a step S522 of bonding the second sheet of flexible material 322 to the thickness defining element 330. In the figure, such bonding is indicted by B2. Preferably, the thickness defining element 330 has an elongated shape with two longer edges, and the longer edge other than the one which has been bonded to the first sheet of flexible material 321 can be bonded to the second sheet of flexible material 322. In some embodiments the bonding B2 is substantially in the longitudinal direction of the inflatable bladder and preferably in a middle portion thereof, in the width direction.
[0158] The method 500 can then further comprise a step S523 of bonding the first sheet of flexible material 321 to the second sheet of flexible material 322. In the figure, such bonding is indicted by B3. An opening O might be left open for acting as a fluid connection.
[0159] The above described method 500 is particularly advantageous in that it allows the inflatable bladder 310 to be obtained with a reduced number of steps. As can be seen in
[0160] Alternatively, or in addition, as illustrated in
[0161] In particular,
[0162] Preferably, the thickness defining element 330 has a shape with two longer edges and the bending step S630 is performed such that those two longer edges substantially overlap after the bending.
[0163] Thanks to the bending step, as visible in
[0164] It has thus been described how a pneumatic bladder arrangement can be manufactured and/or structured so as to be mounted on a seat. The difference in thickness at the extremities of the bladders of the pneumatic bladder arrangement, and in particular their wedge-like shape, allow advantageous uses of the pneumatic bladder arrangement, some examples of which have been indicated, in particular as shoulder or cushion support.
[0165] While various features have been described as being combined to implement given embodiments, one or more features from one or more embodiment can be combined in any manner resulting in additional embodiments, as will be clear to those skilled in the art.
LIST OF REFERENCE NUMERALS
[0166] 100: pneumatic bladder arrangement [0167] 110: inflatable bladder [0168] 111, 112, 113, 114: edge [0169] S: seat [0170] T1, T2: thickness [0171] 210: inflatable bladder [0172] 211, 212, 213, 214: edge [0173] W1, W2: width [0174] 310: inflatable bladder [0175] 311, 312, 313, 3140: edge [0176] 321, 322: sheet of flexible material [0177] 330: thickness defining element [0178] 331: median line [0179] W3, W4: width [0180] 410: inflatable bladder [0181] 430: thickness defining element [0182] 431-436: portion [0183] 500: manufacturing method [0184] S510: providing step [0185] S521-S523: bonding step [0186] B1, B2, B3: bonding line [0187] O: opening [0188] 600: manufacturing method [0189] S630: bending step [0190] 700: pneumatic bladder arrangement [0191] 740: overlapping regions [0192] 800: pneumatic bladder arrangement [0193] 900A: pneumatic bladder arrangement [0194] 900B: pneumatic bladder arrangement [0195] 950/1, 950/2: fluid interconnection [0196] 960/1, 960/2, 960/3: fluid supply connection [0197] V1, V2, V3: valve [0198] 1000: pneumatic bladder arrangement [0199] C: cushion [0200] 1100: pneumatic bladder arrangement [0201] 1210: inflatable composite bladder [0202] 1210A, 1210B: sub-bladder [0203] 1221, 1222, 1223, 1224: sheet of flexible material [0204] H: communication hole [0205] NST: non-stretchable trim [0206] ST: stretchable trim