Pneumatic Cushion

Abstract

A pneumatic cushion for use as a sitting, lying and reclining cushion. The cushion includes a casing made from limited-extensibility material. The casing includes a plurality of webs made from limited-extensibility material, the plurality of webs are adapted to divide a cross-section of the pneumatic cushion into a plurality of chambers and positively connect opposite sides of the casing to each other thereby limiting the cushion's maximum spread at web level. A plurality of gas-tight bladders capable of being pressurized with a pressure fluid are inserted in each of the plurality of chambers created by the plurality of webs and the casing.

Description

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a pneumatic cushion, particularly for use as a sitting, lying and reclining cushion.

2. History of Related Art

Pneumatic sitting, lying and reclining cushions are known in the art. They comprise, for example, a plurality of juxtaposed communicating air tubes or air vessels, which can be inflated and deflated via a common valve, and therefore resemble the known airbed in structure and form.

A main problem associated with pneumatic cushions involves giving the cushion a predetermined form without making it hard and uncomfortable as a result. A bladder made from flexible material will immediately take on a substantially spherical shape when inflated. In order to give the cushion a particular form other than that of a sphere, the person skilled in the art will be familiar with the use of inflexible fabrics cut to shape, combinations of air vessels or air chambers and/or webs. The stiffer this fabric, however, and/or the more internal, shaping textile webs contained in the cushion, the stiffer and more uncomfortable it becomes. The problem therefore involves finding the best possible compromise between the dimensional stability and softness of the cushion.

One example of a pneumatic sitting cushion made up of air tubes placed side by side is disclosed in WO 94/07396.

SUMMARY OF THE INVENTION

The object of the present invention is to create a pneumatic cushion, particularly for use as a sitting, lying and reclining cushion, which offers good dimensional stability, is able to satisfy rigorous requirements in relation to sitting comfort and has a substantially smooth surface without bulges caused by air tubes. In particular, despite great freedom in relation to design options for its form, the cushion should not become stiff or even hard, as is usually invariably the case when using many shaping webs.

The object of the present invention is to create a pneumatic cushion, particularly for use as a sitting, lying and reclining cushion, which facilitates a good design, deviating from the usual round, pneumatic forms, in addition, has a substantially smooth, bulge-free surface and, at the same time, guarantees a high standard of sitting comfort. In particular, the structure should not become stiff or even hard, despite great freedom in the design options for its form. Furthermore, the cushion should be capable of being produced simply and cost-effectively.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the pneumatic cushion of the present invention may be obtained by reference to the following Detailed Description, when taken in conjunction with the accompanying Drawings, wherein:

FIG. 1 a shows a schematic representation of a first embodiment in cross-section;

FIG. 1 b shows a schematic representation of a first embodiment in longitudinal section (smaller scale);

FIG. 2 shows a schematic representation of a second embodiment in cross-section;

FIG. 3 shows a third embodiment in cross-section;

FIG. 4 shows a schematic representation of a fourth embodiment in cross-section;

FIG. 5 shows a schematic representation of a fifth embodiment in cross-section; and

FIG. 6 shows a schematic representation of a sixth embodiment in cross-section.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 a shows a first embodiment in cross-section. A not necessarily gas-tight, substantially inflexible or limited-extensibility casing 1 contains several webs 2, which are likewise made from substantially inflexible or limited-extensibility material and divide the cross-section of the pneumatic structure into four chambers. A textile fabric, for instance, may be used as the limited-extensibility, substantially inflexible material.

The chambers are created by four star-shaped webs 2 radiating from a central axis 5 lying substantially lengthways inside the cushion to the casing 1. A gas-tight bladder 3 is inserted in each of these chambers. This bladder 3 is made from a thin, gas-tight, flexible membrane, for example, PU film. It may be produced from sections of tube, for example, by heat-sealing the two ends together. The bladders 3 are either each provided with a valve 4, through which they can be individually pressurised, or the bladders 3 communicate via lines or openings and create networks of bladders 3.

The casing 1 may, for example, be positively connected to the webs 2 simply and cost-effectively by sewing. The seams need not have costly gas-tight seals. The casing 1 provides the cushion along with the webs 2 with its form and, in addition, offers the airtight bladders 3 protection from mechanical action. Primarily, the bladders 3 assume only a sealing function in relation to the pressure gas. The shape of the cushion is determined by the cut of the substantially inflexible casing 1 and the form and configuration of the substantially inflexible webs 2.

FIG. 1 b shows the first embodiment in longitudinal section A-A′. This figure is presented on a smaller scale to provide a better illustration than that of the cross-section in FIG. 1a. The webs 2 run over the entire length of the cushion.

By separating the sealing function, undertaken by the bladders 3, and shaping, undertaken by the substantially inflexible casing 1 and the substantially inflexible webs 2, the cushions can be produced simply and cost-effectively.

FIG. 2 shows a second embodiment in cross-section. The cushion has eight chambers rather than four created by eight star-shaped webs 2 radiating from the central axis 5 to the casing 1 and the casing 1.

A third embodiment is depicted in cross-section in FIG. 3. A further possible configuration of the webs 2 is shown. The webs 2 have partial openings, which connect the bladders 3 to each another and enable the pressure to be equalised between the different bladders 3. A single valve 4 is sufficient to pressurise several networks of bladders 3 communicating through openings 6. The openings 6, represented by substitution in FIG. 3, are present in accordance with the invention in communicating bladders 3 in the other embodiments, even if this is not evident from the cross-sections. The webs 2 are disposed in a star shape around two central axes 5.

FIG. 4 shows a fourth embodiment, in which the webs are positively connected to the casing 1 on both sides and come into contact with or penetrate each another. The chambers are juxtaposed lengthways. The bladders 3 are subject to different pressures p1, p2, p3. This means that the core of the cushion can be subject to a lower pressure, for example, making it softer than the edge of the cushion, or vice versa. Each bladder 3 or each network of communicating bladders 3 is fitted with at least one valve 4. Different pressure regimes are conceivable for all web 2 and casing 1 configurations in accordance with the invention, with openings or lines 6 added between the communicating bladders 3.

FIG. 5 shows schematically a cross-section through a fifth embodiment. A chamber in the cross-section is completely surrounded by webs 2 and is adjacent to further chambers on all sides. The smaller bladders 3, which are disposed around the large inner bladder 3, may be subject to a lower pressure, for instance, than the larger bladder 3 disposed in the centre. This produces a cushion with a soft surface and a compact core, which displays good sitting comfort without becoming badly deformed when a load is applied.

FIG. 6 shows a multi-layered sixth embodiment. The webs 2 form a grid in cross-section with three layers of chambers laid on top of one another. At the ends, two chambers with bladders 3 inserted seal off the cushion. It is evident from this embodiment that the webs 2 need not necessarily be attached or sewn to one another in such a manner that continuous webs are formed in a horizontal and vertical direction, for example. Instead, the webs 2 can be staggered relative to one another, as on the side edges of this embodiment.

Further embodiments in accordance with the invention can be produced by the person skilled in the art by freely combining features of the various embodiments shown above.

Claims

1. A pneumatic cushion for use as a sitting, lying and reclining cushion, comprising: a casing made from limited-extensibility material; a plurality of webs within the casing and made from limited-extensibility material, the plurality of webs are adapted to divide a cross-section of the pneumatic cushion into a plurality of chambers and positively connect opposite sides of the casing to each other, thereby limiting the cushion's maximum spread at web level; and a plurality of gas-tight bladders capable of being pressurized with a pressure fluid are inserted in each of the plurality of chambers created by the plurality of webs and the casing.

2. The pneumatic cushion according to claim 1, wherein the plurality of bladders are connected to each other by means of openings or lines and are subject to the same pressure.

3. The pneumatic cushion according to claim 1, wherein each bladder of the plurality of bladders or each network of communicating bladders is fitted with at least one valve subjecting the plurality of bladders to be pressurized at different pressures.

4. The pneumatic cushion according to claim 1, wherein the plurality of bladders are made from plastic tubes heat-sealed at both ends and provided with openings or lines.

5. The pneumatic cushion according to claim 1, wherein at least one bladder of the plurality of bladders is centrally positioned and only adjoins the plurality of webs but not the casing in cross-section.

6. The pneumatic cushion according to claim 1, wherein the casing is made from textile, limited-extensibility material.

7. The pneumatic cushion according claim 1, wherein the plurality of webs are made from textile, limited-extensibility material.