WO2005114015A1

WO2005114015A1 - Valve

Info

Publication number: WO2005114015A1
Application number: PCT/GB2005/001982
Authority: WO
Inventors: Erik Kaas; John Charles Mark Langley
Original assignee: Venture One (Ip) Limited
Priority date: 2004-05-22
Filing date: 2005-05-20
Publication date: 2005-12-01
Also published as: GB0411506D0

Abstract

A valve (1) for use with lightweight inflatable structures is a substantially flat tube (2) of substantially gas impermeable material. It has with an inlet portion (6) for coupling with inflation means and an outlet portion (12) for coupling with a gas inlet (28) on an inflatable structure (24). The outlet (12) and inlet (6) portions are separated by a valve closure portion (20). The valve closure portion (20) and inlet portion (6) are of a resiliently foldable material. They are creased at opposite side edges so that the tube (2) tends to maintain a substantially flat form when not internally pressurised. The valve closure portion (20) is foldable back upon itself so as to hold the inner walls of the tube (2) in substantial sealing contact with each other across the width of the tube. Lightweight thin film inflatable structures including the valve are also described.

Description

VALVE

The present invention relates to a valve for the inflation of lightweight inflatable structures such as tubes made from polyethylene blown film or other film forming polymers ( 'tube films' ) .

Lightweight inflatable structures formed from tube films or the like, are suitable for use in collapsible, highly compact when packaged, devices such as the inflatable embodiment of a disposable device for the capture and containment of dog faeces, as disclosed in European patent No EP 0778 729.

Such devices require an inflation means coupling including a valve, which allows the user to inflate the device, maintain it in its inflatable state for use, and if required, deflate the device after use.

A valve for the inflation of such lightweight structures is itself desirably lightweight, highly compact and/or collapsible into a highly compact form. It should be easy to deploy for inflation, simple to open and close, and economic to manufacture and attach to the inflatable structure. Cost considerations are particularly important when the inflatable structure is intended to be a low cost, high usage disposable item.

It is an object of the present invention to provide a valve for use in the inflation of lightweight inflatable structures that meets one or more of the aforementioned requirements . It is a further object of the invention to provide collapsible lightweight inflatable structures including a valve of the invention.

According to a first aspect the present invention provides a valve suitable for use with a lightweight inflatable structure having a gas inlet, said valve comprising a substantially flat tube of substantially gas impermeable material with an inlet portion formed and arranged for coupling, in use, with inflation means, an outlet portion formed and arranged for coupling, in use, with a said gas inlet on said inflatable structure, said outlet portion being separated from said inlet portion of the tube by a valve closure portion, at least said valve closure portion and said inlet portion being of a resiliently foldable material, and creased at opposite side edges so that said tube tends to maintain a substantially flat form, at least when not internally pressurised, said valve closure portion being formed and arranged so as to be foldable back upon itself so as to hold the inner walls of the tube in substantial sealing contact with each other across the width of the tube.

The inlet portion of the tube may simply be constituted by an open end of the tube, insertable into the mouth of a user constituting the inflation means. Other inflation means such as a small gas cylinder can also be employed. The valve may be closed by simply holding the tube folded over across its width at said valve closure portion between the inlet and the outlet. It will be appreciated that the tube can be folded over generally in any direction, provided the fold is across the width of the valve so as to hold the inner walls in sealing contact. Preferably the substantially flattened tube is folded over in a line from one creased opposite side edge to the other.

Opening of the valve for the purposes of deflation of the inflatable structure as and when required, may be effected by simply releasing hold of the folded over tube, whereupon the combination of gas pressure inside the structure and resilient unfolding of the tube, will allow the sealed together walls at the valve closure portion to separate and allow gas to pass therebetween. If desired this may be assisted by actively unfolding the folded over tube. It will be appreciated in this connection that during deflation the inlet portion of the valve will now function as an outlet etc, and references to inlet portion and outlet portion herein should be construed accordingly.

The outlet portion of the valve may be formed and arranged in various different ways depend on the desired form of coupling to the inflatable structure - and hence the form of inflatable structure inlet used therein. In one form of the invention the outlet portion may simply comprise an end portion with an open end, for (internal or external) sleeving interengagement with an open end of a tubular portion of the inflatable structure with an annular seal provided by bonding together between at least part of the inter-sleeved valve and inflatable structure portion.

In another form of the invention, the outlet portion may constitute an end portion with a closed end and an aperture in a side wall which can be overlapped with a similar aperture in the inflatable structure constituting an inlet therein with an annular seal around the overlapped apertures provided by bonding between the valve tube side wall and the inflatable structure. In yet another form of the invention either or both of the side wall apertures may be extended up to the end of the tube or tubular portion so that the end of the tube or tubular portion is also open. In such a case sealing coupling can be provided by bonding of the free edges of the exposed inside wall of the end tube or tubular portion and the outside wall edge of the tube or tubular portion adjacent the exposed inside wall. It will be appreciated that a particular benefit of the generally "sandwich" form of the various valve-to- inflatable structure coupling methods described above, is the highly compact (small thickness) nature thereof, which in turn enables the inflatable structure and valve assembly to be rolled and/or folded up into a highly compact form. Bonding can be achieved in various different ways including heat sealing or welding, and adhesive bonding. Most conveniently there is used double-sided adhesive tape.

Desirably the material of (at least said inlet portion and valve closure portion) of the tube has sufficient stiffness to maintain a substantially flat form creased at opposite side edges and for the tube to be substantially self- supporting so as to facilitate coupling thereof to the inflation means and increase the sealing pressure between the opposed tube walls at the valve closure portion in the folded over condition thereof. Nevertheless said material is also desirably sufficiently flexible to allow the substantially flat valve to be folded and/or rolled up in any convenient manner when packaged with a lightweight collapsible inflatable structure and then readily unfolded or unrolled when the valve and inflatable structure are deployed for use. It will be appreciated that the resilience of said material also helps to maintain an adequate sealing contact between the inner walls of the tube when the valve closure portion is folded over to close.

Preferably the valve of the invention is made from polyethylene or other polymer film having the required flexibility and stiffness properties. The tube may be made from polyethylene or other polymer film blown in the form of a tube or from sheets of polyethylene or other suitable polymer bonded, for example by gluing or welding at opposite edges to form the tube. Laminated plastic films may also be used. The use of a biodegradable material, preferably, a biodegradable polymer film, is desirable especially in use of the valve with high usage disposable inflatable structures. Other materials of construction such as cardboard or plastics film coated cardboard can also be envisaged.

Preferably the structure of the valve of the invention is further modified by the provision of at least one deformation of at least one of the walls of the flattened tube running generally axially along at least the inlet portion of the tube (and possibly also the valve closure portion) , spaced from said side edge creases, and formed and arranged so as to urge said at least one wall slightly away from the opposed tube wall. Such a deformation has the effect of assisting in the avoidance of adhesion between the two opposed inner walls of the substantially flattened tube. This facilitates the opening of the tube inlet-portion by the user when coupling to the inflation means. The deformation may also have the effect of slightly increasing the resilience of the tube wall, encouraging the opening or unfolding of the valve portion after closure. The deformation may take the form of one or more ridges, ribs or embossed stripes. A suitable deformation can be conveniently provided by embossing a stripe axially along the tube wall during its manufacture.

Alternative deformations to the tube walls, not necessarily running generally axially along a portion of the tube, can also be envisaged. These may, for example, take the form of point deformations such as dimples or pimples, or can be of any other shape that assists the avoidance of adhesion between the opposed inner walls of the substantially flattened tube and/or slightly increases the resilience of the tube wall. Such deformations can be placed singly or in groups at desired locations, such as the inlet portion of the tube. However, it may be convenient and economic in manufacture to prepare the valve tube with deformations, such as dimples, distributed generally across its walls.

Depending on the physical properties (stiffness, resilience, and flexibility) of the valve tube material, the presence of a deformation or deformations at the valve closure portion may be detrimental to the sealing contact between the inner walls of the tube, formed on closing the valve by folding. In such a case the tube material at the valve closure portion can be further modified by, for example, making use of heat treatment or pressure to smooth the area of deformation of the valve wall, at the valve closure portion, permitting better sealing contact on closure of the valve.

Preferably the valve structure is further modified by the provision of means to predispose the tube to folding at the tube closure portion, when the tube is folded back on itself. This can be accomplished by the provision of small spot welds at each side of the flattened tube at either end of the desired fold line of the valve closure portion. These spot welds encourage the valve to fold along a predetermined fold line. Alternative means such as pre- creasing or scoring the valve material may be employed.

Whilst the valve of the invention could in principle be used with a wide range of inflatable structures, they are particularly suited to use with very lightweight structures inflated to relatively low pressures - typically from just sufficiently above ambient pressure to sustain the structure in an inflated state to below the pressure at which the material of the lightweight inflatable structure, or joints formed for its construction, may rupture or leak. It will also be appreciated that for certain applications - such as for example, a canine faecal waste collector, it is only necessary to maintain pressurisation for a few minutes . Accordingly in a preferred form of the invention there is used a tubing material having a stiffness and resilience sufficient to provide substantial sealing in a folded over condition, at a pressure suitable for use of the inflatable structure with a sufficiently low leakage rate so as to maintain the structure in a usable state for a period of at least five minutes . Accordingly in a further aspect the invention provides a lightweight thin film inflatable structure having a gas inlet and a valve, said valve comprising a substantially flat tube of substantially gas impermeable material with an inlet portion formed and arranged for coupling, in use, with inflation means, an outlet portion coupled with said gas inlet on said inflatable structure, said outlet portion being separated from said inlet portion of the tube by a valve closure portion, at least said valve closure portion and said inlet portion being of a resiliently foldable material, and creased at opposite side edges so that said tube tends to maintain a substantially flat form, at least when not internally pressurised, said valve closure portion being formed and arranged so as to be foldable back upon itself so as to hold the inner walls of the tube in substantial sealing contact with each other across the width of the tube.

As previously discussed the valve of the invention can be used with a wide range of inflatable structures but it is particularly suited for use with lightweight structures such as tubes made from film forming polymers ( ' tube films') . It should be appreciated that the inflatable structure can be constructed of a plurality of tube films formed and arranged as required to form the desired shape on inflation. If provision is made of means, such as suitable apertures, to provide gas communication between the interiors of the tube films, then only one valve is needed to inflate an inflatable structure comprising two or more tube films. Alternatively the inflatable structure can be provided with a plurality of valves to inflate separate tube films of the structure as required.

In one embodiment a ring of adhesive such as hot melt or pressure sensitive adhesive provides the seal surrounding the outlet of the valve and the inlet of the inflatable structure. It will be appreciated by the reader that this seal can also provide an economic means of attachment to secure the valve to the inflatable structure during use. If the inflatable structure of this embodiment is rolled or folded into a compact shape for storage or transport, the free (inlet) end of the valve may conveniently be used to secure the packed inflatable structure by sticking it down onto the rolled up and/or folded up inflatable structure by means of a releasable bonding adhesive. In use the package is opened by pulling off the inlet end of the valve from its point of attachment allowing the inflatable structure to be unrolled and/or unfolded for inflation.

In a preferred embodiment use is made of double sided adhesive tape to provide sealing means between the valve outlet and the inlet of the inflatable structure. A piece of double sided pressure sensitive adhesive tape, with a cut out corresponding to the valve outlet and inflatable structure inlet is laminated between the valve and the inflatable structure, leaving the valve inlet unattached and free for coupling of the inflation means. This method of providing sealing means and attachment between the valve and the inflatable structure has the advantage of providing extra strength, reducing the possibility of tearing during handling or use. Desirably an edge of the adhesive bonding zone between the tube valve and inflatable structure is disposed adjacent the intended valve closure folding line of the valve tube. This has the effect of encouraging closure of the valve in the correct location.

In a particularly convenient embodiment, a portion of the piece of double sided adhesive tape used as sealing means, is not covered by the valve, thereby leaving an exposed adhesive surface positioned for interengagement, with the free (inlet portion) end of the valve to form a securing tie for the inflatable structure when is it rolled and/or folded up into a pre-use transportation condition, and conveniently also when the structure is inflated, and the valve closed by folding, to secure the valve tube in its folded state to maintain inflation.

Alternative means of securing the valve closed when the structure is inflated can be provided, for example, by the separate provision of a piece of double sided adhesive tape or a patch of tacky material, such as a pressure sensitive adhesive, suitably placed on the inflatable structure or on the valve for interengagment with the free (inlet portion) end of the valve when the valve is closed by folding.

Further preferred features and advantages of the present invention will appear from the following detailed description of some preferred embodiments illustrated with reference to the accompanying drawings in which:

Fig. 1 is a perspective view of one embodiment of the valve of the invention; Fig.2 is a perspective view of a strip of inflatable structures of the invention prior to separation thereof, showing attachment thereto of a valve of the invention, in the course of manufacture; Fig.3 is a perspective view of packed examples of the lightweight inflatable structures of Fig.2;

Fig. 4 is a perspective view of a modified embodiment generally similar to that of Fig. 2;

Fig. 5 is a perspective view of a preferred embodiment of lightweight inflatable structure with a valve generally similar to that of Fig. 1; and

Fig.6 A-C is a series of perspective views illustrating different possible coupling arrangements of valves to lightweight inflatable structures in accordance with the present invention.

Reference is made to Figure 1 which shows a valve generally indicated by reference number 1 in the form of a substantially flattened tube 2. The tube 2 has an open ended 4 end portion 6 constituting a gas inlet portion and an outlet aperture 8 in the (underside) wall 10 of an outlet portion 12 of the tube 2, whose distal end 14 is sealed closed. The valve 1 is also provided with two small spot welds 16 at either side of the flattened tube 2 to encourage folding of the tube 2 at a fold line 18 extending therebetween in a valve closure portion 20, between the inlet 6 and the outlet portion 12 when the valve is closed. The valve of Fig. 1 also has a deformation in the form of an embossed stripe 22 running along the length of the tube 2 to facilitate use of the valve 1 as previously described. Attachment of the valve 1 to a lightweight inflatable structure 24 is shown in following Figures. Figure 2 illustrates coupling of a valve 1 to a lightweight inflatable structure 24. A strip of lightweight inflatable structures comprising a film tube 26 having a gas inlet 28 constituted by an aperture 30 in a wall 32 of the film tube 26. A ring of adhesive 34, such as a hot melt adhesive, is attached to the tube wall 32 around the gas inlet 28. An additional ring of adhesive 36 is positioned offset from and marginally overlapping with, the inlet adhesive ring 34. In manufacture the outlet aperture 8 from the valve is placed to coincide with the gas inlet 28 of the inflatable structure 24 and the ring of adhesive 34 couples the valve outlet 8 and the inflatable structure inlet 28 in a suitably gas tight manner. The open inlet end portion 6 of the valve 1 remains free until the inflatable structure tube 24 with valve 1 is packaged by rolling up as shown in Fig. 3, with the free inlet end 6 of the valve 1 attached by means of the second adhesive ring 36, to secure the package in its rolled up condition, until it is required to be unrolled and deployed.

Figure 4 illustrates an alternative arrangement generally similar to that of Fig. 2, in which a second adhesive ring 38, used to secure the rolled inflatable structure when packed up, is placed on the exposed outward surface 40 of the substantially flattened valve.

Figure 5 illustrates a preferred embodiment wherein the valve 1 is attached to the inflatable structure 24 by means of a generally rectangular annular adhesive coupling ring 42 of double sided adhesive tape which has a central aperture 44 through which the outlet aperture 8 of the valve 1 and the inlet portion 28 of the inflatable structure 24 interconnect. The coupling ring 42, in addition to sealing the valve outlet 8 and the inflatable structure inlet 28, also serves to attach the valve 1 to the inflatable structure 24. The adhesive tape coupling ring 42 is sized and placed so as to leave a securing portion 46 of its outer adhesive surface 48 exposed extending beyond the valve 1 attached to the other portion 50 thereof and this is used to attach the inlet portion 6 of the valve 1 when securing the rolled up packaged article in the manner shown in Figure 3. In use the valve inlet portion 6 is pulled free of the adhesive tape coupling ring 42, whereupon, the inflatable structure may be deployed and inflated and then the valve 1 closed by folding it back on itself as previously described. Closure is conveniently secured by pressing the folded valve portion against the adhesive surface 48 of the securing portion 46.

In Figure 6A an embodiment of the valve is shown in which the valve outlet 8 is constituted by an open end portion 4 of the valve 1. The outlet portion 12 of the valve 1 is sleeved inside a tubular end portion 52 of the inflatable structure 24 which acts as the gas inlet 28. In this case the inside wall faces 54, inlet end portion 56 of the inflatable structure 24, are bonded 58 to the superposed outside wall faces 60 of the valve outlet portion 12, or each other, as indicated by cross-hatching.

In Figure 6B a valve 1 of the form illustrated in Figure 1 with an outlet portion 12 having a sealed distal end 14 and an outlet aperture 8 in the underside wall 10 of the valve 1, is shown coupled to the inflatable structure in a similar inter-sleeved fashion to that shown in Fig. 6A, but with the adhesive bonding 58 between the inside wall faces 54 of the inflatable structure inlet end portion 56 and the outside wall faces 60 of the valve outlet portion 12, stopping short of the aperture 8.

In Figure 6C the apertures 8, 30 constituting the outlet 8 of the valve 1 and the inlet 28 of the inflatable structure are in the side walls and extend up to the end 14, of the valve tube 1 and the end 62 of the tubular end portion 52 of the inflatable structure 24, respectively. Sealing coupling around the overlapped apertures 8, 30, is achieved by bonding 58 the free edges 64 of the exposed inside wall 66 of the tube 1 and the adjacent free edge 68 of the outside wall 70 to the edges 72, 74 opposed outside and inside wall faces 76, 78 of the tubular end portion 52 of the inflatable structure 24.

The valves illustrated in the drawings may for example, be constructed of blown polyethylene film of about 150μm thickness with the width of the flattened tube being about 20mm for easy inflation by mouth by a user. Length of the valve is as required to allow attachment of the inflation means, closure of the tube following inflation and use of the inlet portion of the valve to secure the rolled or otherwise packaged inflatable structure. A typical tube film, lightweight inflatable article may be manufactured from blown polyethylene film of 40-45μm thickness. A commercially available polyethylene which can be used to make examples of both the lightweight inflatable article and the valve of the invention, conforming to the above dimensions, is Borstar^® type 2230 manufactured by Borealis

A/S.

It will be appreciated that various modifications may be made to the above described embodiments without departing from the scope of the invention.

Claims

CLAIMS 1. A valve (1) suitable for use with a lightweight inflatable structure (24) having a gas inlet (28) , said valve (1) comprising a substantially flat tube (2) of substantially gas impermeable material with an inlet portion (6) formed and arranged for coupling, in use, with inflation means, an outlet portion (12) formed and arranged for coupling, in use, with a said gas inlet (28) on said inflatable structure (24) , said outlet portion (12) being separated from said inlet portion (6) of the tube by a valve closure portion (20) , at least said valve closure portion (20) and said inlet portion (6) being of a resiliently foldable material, and creased at opposite side edges so that said tube (2) tends to maintain a substantially flat form, at least when not internally pressurised, said valve closure portion (20) being formed and arranged so as to be foldable back upon itself so as to hold the inner walls of the tube (2) in substantial sealing contact with each other across the width of the tube.

2. A valve (1) according to claim 1 wherein the outlet portion (12) is an end portion with an open end (4) , for internal or external sleeving interengagement with an open end of a tubular portion (52) of said inflatable structure (24) , with an annular seal provided by bonding together between at least part of the inter-sleeved valve (1) and inflatable structure portion (52) .

3. A valve (1) according to claim 1 wherein the outlet portion (12) is an end portion with a closed end (14) and an aperture (8) in a side wall (10) which, in use, is overlapped with a similar aperture in said inflatable structure constituting an inlet therein, with an annular seal around the overlapped apertures provided by bonding

(58) between the valve tube side wall (60) and the inflatable structure (24) .

4. A valve (1) according to claim 1 wherein the outlet portion (12) is an end portion with an aperture (8) in a side wall extending up to the end (14) of the tube (2) which, in use, is sealingly coupled to a side wall aperture (30) of the inflatable structure (24) .

5. A valve (1) according to any one of claims 1 to 4 , which is made from a polymer film.

6. A valve (1) according to claim 5, which is made from a polyethylene film.

7. A valve (1) according to any one of claims 1 to 5, which is of a biodegradable material .

8. A valve (1) according to any one of claims 1 to 7 wherein the material of said tube (2) ; has sufficient stiffness to maintain a substantially flat form creased at opposite side edges and for the tube to be substantially self-supporting so as to facilitate coupling thereof to the inflation means and increase the sealing pressure between the opposed tube walls at the valve closure portion in the folded over condition thereof; and is sufficiently flexible to allow the substantially flat valve to be folded and/or rolled up in any convenient manner when packaged with a lightweight collapsible inflatable structure and then readily unfolded or unrolled when the valve and inflatable structure are deployed for use.

9. A valve (1) according to any one of claims 1 to 8 further modified by the provision of at least one deformation (22) of at least one of the walls of the flattened tube (2) running generally axially along at least the inlet portion (6) of the tube, spaced from said side edge creases, and formed and arranged so as to urge said at least one wall slightly away from the opposed tube wall.

10. A valve (1) according to claim 9 wherein said deformations are ridges, ribs or embossed stripes.

11. A valve (1) according to any one of claims 1 to 8 wherein is provided at least one point deformation of at least one of the walls of the flattened tube (2) , formed and arranged so as to urge said at least one wall slightly away from the opposed tube wall .

12. A valve (1) according to any one of claims 1 to 11, which is provided with means to predispose the tube (2) to folding at the valve closure portion (20) , when the tube is folded back on itself, said means comprising spot welds (16) at each side of the flattened tube (2) , a crease, or a score at a predetermined fold line (18) .

13. A valve (1) according to any one of claims 1 to 12 wherein the tubing material has a stiffness and resilience sufficient to provide substantial sealing in a folded over condition, at a pressure suitable for use of a very lightweight inflatable structure with a sufficiently low leakage rate so as to maintain the structure in a usable state for a period of at least five minutes.

14. A lightweight thin film inflatable structure (24) having a gas inlet (28) and a valve, said valve (1) comprising a substantially flat tube (2) of substantially gas impermeable material with an inlet portion (6) formed and arranged for coupling, in use, with inflation means, an outlet portion (12) coupled with said gas inlet (28) on said inflatable structure (24) , said outlet portion (12) being separated from said inlet portion of the tube (2) by a valve closure portion (20) , at least said valve closure portion (20) and said inlet portion (6) being of a resiliently foldable material, and creased at opposite side edges so that said tube (2) tends to maintain a substantially flat form, at least when not internally pressurised, said valve closure portion (20) being formed and arranged so as to be foldable back upon itself so as to hold the inner walls of the tube (2) in substantial sealing contact with each other across the width of the tube.

15. A lightweight thin film inflatable structure (24) according to claim 14 wherein the said structure is constructed of a plurality of tube films (26) formed and arranged to form the desired shape on inflation.

16. A lightweight thin film inflatable structure (24) according to claim 15, which is provided with a plurality of said valves (2) to inflate separate tube films (26) of the structure as required.

17. A lightweight thin film inflatable structure (24) according to claims 14 or 15 wherein double sided adhesive tape (42) provides sealing means between the valve outlet (8) and the inlet (28) of the inflatable structure (24) .

18. A lightweight thin film inflatable structure (24) according to claims 14, 15 or 17 wherein an edge of the adhesive bonding zone between the valve (1) and inflatable structure (24) is disposed adjacent the intended valve closure folding line (18) of the valve tube (2) .

19. A lightweight thin film inflatable structure (24) according to claim 17 wherein a portion (46) of the piece of double sided adhesive tape (42) is not covered by the valve (2) , thereby leaving an exposed adhesive surface (48) positioned for interengagement, with the free inlet portion (6) end of the valve (1) to form a securing tie for the inflatable structure (24) when the structure is rolled and/or folded up into a pre-use transportation condition, and conveniently also when the structure is inflated, and the valve (1) closed by folding, to secure the valve tube (2) in its folded state to maintain inflation.