GB2374047A

GB2374047A - Inflatable device for sealing holes in boats

Info

Publication number: GB2374047A
Application number: GB0203087A
Authority: GB
Inventors: Michael John Livesy
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-04-06
Filing date: 2002-02-11
Publication date: 2002-10-09
Anticipated expiration: 2022-02-11
Also published as: GB2374047B; GB0203087D0

Abstract

A device (10, Fig 1) for temporarily sealing a hole in a boat comprises an inflatable assembly comprising one or more inflatable structures 16 that when inflated each form at least one rigid torus shaped ring. Material for sealing 34 is supported by said torus such that the inflatable structures cannot come into direct contact with the hole space post deployment and such that the inflatable structures are not used for direct structural support of said material for sealing over the hole space. The inflatable assembly is mounted at one end of a pole 12 which has a gas delivery system at the other end. The gas delivery being achieved through the use of a hand pump or a compressed gas cylinder (26, Fig 1) pierced by a pin (24, Fig 1). A protective cover (14, Fig 1) that holds the inflatable structures in a small pre-deployment diameter is also provided.

Description

INFLATABLE HOLE SEALING DEVICE FOR BOATS This invention relates to a device to temporarily seal holes in boats.

The main problems associated with sealing a hole in a boat are the large volume of water that flows through even a small hole and the large pressure or force of water that must be withheld to maintain a seal. To seal a hole there are two choices as to deployment, that is deployment from the inside of a boat against the inflow of water, or deployment from the outside of a vessel. The preferred method for deployment of the current invention is from the inside, only those issues concerning this method will therefore be discussed. For deployment from the inside the immediate problem is the inflow of water against which the device must be pushed. Therefore for a device to be useful for this purpose it must have a small diameter pre-deployment. Many attempts have been made to produce a solution that will overcome the above problems, such as in US pat. No. 3,841, 256 or US pat No. 5,143, 012 where

inflatable bags or balloons were used. Although such devices can enabled the essential feature of a small diameter prior to deployment the use of a bag to plug a hole cauignificant risk of failure due to puncturing. The use of multiple layer fabrics and tougher materials does not solve the problem

of puncturing and only serves to increase the diameter of the device prior to deployment. Furthermore, the use of multiple fabrics and multiple layers cause an increase in complexity and therefore increase in the cost of manufacture. As an alternative to an inflatable device mechanical methods of sealing a hole have also been proposed such as GB 1450861, US pat No. 5,253, 602 and US pat No. 2,220, 085, these devices employ an umbrella type mechanism where ridged arms are used to support a bladder or sheet of material. Although such devices can be made with enough strength to withstand the pressure of water once deployed, it is not possible to make the pre-deployment diameter small enough to allow the devices to be deployed in the first instance, furthermore the complexity of the mechanisms results in them not being efficacious. An attempt was made in US pat No. 4, 385. 582 to employ the use of ridged arms as in a mechanical umbrella device but to form the arms from inflatable passages or ribs; that patent was itself derived from the idea of an inflatable umbrella in US pat No. I, 411, 560. It was suggested in that patent that by forming the device into a dome or convex shape the water pressure could be withheld, however, just as an ordinary umbrella such a shape is as risk of inverting when under load, with consequent failure. Additionally, a dome structure is both expensive to manufacture and the requirement of thick walled materials make such a device difficult to fold to a small predeployment diameter.

Therefore an object of this invention is to provide a method to quickly seal a hole of varying sizes and located anywhere between the waterline to a significant depth in the hull of a vessel that is simple, capable of small pre-deployment diameter, and does not present a risk of failure due to puncturing.

Accordingly, this invention provides an inflatable device to seal a hole and includes the essential features of a ridged or semi-ridged torus shaped structure that supports material for sealing, such that the inflated sections of the inflatable cannot come into direct contact with the hole space post deployment and where direct structural support for the sealing material does not cover the hole space.

A preferred embodiment of the invention will now be described with reference to the accompanying drawings in which: FIGURE I shows a side view of the device with cross sections.

FIGURE 2 shows a side view cross section of the inflatable assembly and connectors.

FIGURE 3 shows a side view cross section the inflatable structures when in use.

FIGURE 4 shows a top view of the inflatable assembly.

Referring to the drawings the device, 10, basically comprises a pole, 12, an inflatable structure, 16, and a protective covering, 14. The chosen structure for the inflatable is derived from a torus or annulas, such a shape has a great deal of strength and is able to support a load over it's centre, this is demonstrated from the use of an inflatable torus in small trampolines, such as in FR2698792. Once a hole is detected the inflatable end of the device, 10, should be pushed through the hole against the flow of water. The device should be pushed far enough through the hole to allow the inflatable structure, 16, to inflate without being sucked back through the opening. Once fully inflated the device can be pulled back against the hole, the water pressure should form the necessary seal. Should water still continue to flow past the device, the pole, 12, can be clamped firmly in position by any suitable method, preferably holes on the handle, 20, can be used to lash the device to any available structure.

Figure I shows a side view of a device that is preferably deployed from the inside of a ship. The device, 10, comprises a pole, 12, and an inflatable structure,} 6, that is housed by a protective covering, 14. Prior to deployment the pole, 12, and protective covering, 14, have minimal radial cross section.

The pole comprises a handle, 20. The handle, 20, preferably comprises holes for lashing and a threaded locking collar. A valve assembly, 24, comprises a threaded bore, a diameter such that it can be inserted into the pole, 12, and a shoulder on to which the locking collar of the handle, 20, can apply force. A side hole should also be suitably located in the valve assembly, 24, to allow the venting of gas into the bore of the pole 12. A rubber 0-ring is preferably used under the shoulder ofthe valve assembly, 24, so that when the locking collar is installed a good seal can be attained. A small gas cylinder, 26 should be screwed into one end of the valve assembly, 24, a pin connected to a threaded handle, 22 should be screwed into the other end. To activate the device the threaded handle, 22, is merely screwed clockwise piercing the gas cylinder with the pin. Optionally a plastic spacer can be placed between the locking collar and the threaded handle, 22 to prevent premature deployment of the device. The plastic spacer should be easy to remove prior to usage. There are many other ways of facilitating the release of compressed gas such as a spring-loaded pin activated by a button, or a gun style handle as used on a fire extinguisher ; any suitable means can be substituted. The use of a locking collar on the handle, 20, allows for many different methods of releasing the gas to be substituted without changing any of the other components. It is additionally possible to incorporate a hand pump into the device so that the inflatable structure, 16, can be inflated or re-inflated by hand. The shape of the inflatable structure, 16, and the method of attaching the inflatable structure, 16, to the pole, 12, are described below. The protective covering, 14, preferably comprises a plastic sheath that can hinge open, alternatively a shrink wrapped plastic material can be used. The protective covering, 14, is merely to maintain the deflated inflatable structure, 16, in a compact space and to prevent any damage during stowage and deployment, any other suitable method can be substituted; merely using a sheath of fabric with Velcro fastening will suffice. It is also possible to use the bore of the pole, 12, as the protective covering by inserting the folded inflatable structure, 16, into the pole ; in this method the inflatable structure would not be fixed to the pole but would be allowed to fire out the end being restrained preferably by a tether of suitable length. Preferably the pole, 12, is made of metal, such as aluminium. The valve assembly, 24, threaded handle, 22, and handle, 20, are preferably made of plastic materials, suitable metals or a combination thereof.

Figure 2 shows a cross section of the inflatable assembly after deployment. Deployment is best achieved through the use of a small gas cylinder, described above. Once inflated the inflatable structure, 16, comprises a minimum of a one torus ring. Sealing material, 34, preferably comprises a circle of material that is attached to the outer perimeter of the torus and clamped in the centre by the various connectors. Additionally, in this configuration, the inflatable structure, 16, should comprise holes, 36, preferably in the membrane created in the centre of the torus. These holes allow water to pass into the gap between the inflatable structure, 16, and the extra sealing material, 34. In such a way a buffer is created between the inflatable channels and any possible sharp edges within the hole space.

Additionally when water pressure fills this gap the extra sealing material, 34, will tension the inflatable, 16, from the outer perimeter of the torus, this results in an increase in the load that the ring can withstand. Most importantly the main inflated ring of the torus will not come into contact with the hole, which can have sharp edges, any necessary seal is formed by the sealing material; thus the device can be punctured without the inevitability of deflation. The inflatable structure, 16, is preferably made by heat welding two sheets of thermoplastic polyurethane coated nylon together to created an outer ring channel. Additionally if this material and method are used a small radial channel will be required to connect the outer torus with a centre section for gas supply ; the preferred shape of these channels is shown in Figure 4. The shape of the centre section, 30, is preferably similar to a thick coin, it should comprise a hole through its centre and outlet holes through the centre of its edge. In figure 2 both the hole through the centre and two outlet holes are shown. The centre section, 30, should be preferably formed into the inflatable structure, 16; this is easily facilitated when using polyurethane coated nylon.

Additionally if the sealing material, 34, is also made of polyurethane coated nylon it can be welded onto the inflatable structure at the same time the structure is made. The use of polyurethane coated nylon enables the structure of the inflatable to be very thin and flexible yet have high tensile strength, giving the ability to fold the device such that it has a small pre-deployment diameter. It is also possible to make the torus from any watertight material by sewing an inner tube between two sheets of fabric, in such an instance only the outer torus and a flexible tube connecting it to the centre is required. The inflatable structure, 16, can be used without the sealing material, 34, in such an instance it is the material stretched in the centre of the main torus that forms the seal. If using the device in a configuration without a sealing material, 34, the holes, 36, in the inflatable structure would need to be removed in the design so that the diaphragm stretched in the centre of the torus can be used for sealing.

In such a configuration it is preferable for the inflatable structure to be made using the inner tube method so that there is no inter radial channel in the sealing diaphragm, however, it is possible to use extra material, such as a plastic strip, to protect any gas channels in inflatable structure from direct contact with the hole space. The inflatable structure, 16, and sealing material, 34, are preferably held in place by attaching the centre section, 30, between two sealing washers, 32, an end bolt, 28 and an end section IS. In figure 2 all the sections are shown with spaces between them so they are more easily distinguished from each other. The end section, 18 should comprise a thread to allow the end bolt, 28, to be screwed into it. Preferably the end section, 18, should comprise a ball check valve, however, this is not absolutely necessary due to the labyrinth seal that is created by the valve assembly, 24, and threaded handle, 22. The end section, 18, should be securely attached to the pole, 12, preferably by the use of a suitable adhesive. When using the pole, 12, as the protective covering, see above, the end section, 18 should not be fixed to the pole but allowed to slide down the bore of the pole like a plunger, preferably an additional 0-ring is used to form the necessary seal ; all the connectors in this method should have diameters compatible with placement in the bore of the pole, 12. The end bolt, 28, should comprise a method to allow gas flow to the centre section, 30, such as a bore hole and a suitably positioned side vent, once the device has been assembled. The end bolt, 28, can additionally incorporate a safety release valve. The end section, 18, end bolt, 28, sealing washers 32, and centre section, 30, are preferably made of a plastic material or a suitable metal.

Figure 3 shows a side view cross section of the inflatable structure when in use. All of the connectors described above and the pole, 12, are not shown in cross section for diagrammatic clarity. The device is shown in the deployed position to seal the hole as represented by the hull of a boat, 38. The sealing material, 34, is shown bulging through the hole as would happen due to the force of water pressure.

Additionally two inflatable structures, 16, have been mounted axially on top of each other. This feature is enabled by the centre section, 30. The use of more than one inflatable structure, 16, mounted above each other along the axis of the pole, 12, significantly increases the force than can be withheld by the device. Secondary or further inflatable structures can be identical or, as in the diagram, of a reduced diameter to further improve the strength of the inflatable assembly, this will also aid the requirement of a small pre-deployment diameter. It is additionally possible to mount a valve between each inflatable structure either for safety or so that multiple inflatable structures can be inflated to differing pressures.

It is not necessary for secondary or further inflatable structures to have holes, 36, in them and it is advisable for them not to have extra sealing material, 34.

Figure 4 shows a top view of the inflatable structure, 16. Additionally the centre section, 30, is shown by dotted lines. The preferred structure for the inflatable section, 16, is to heat weld two sheets of polyurethane coated nylon fabric to create two tori ring channels and a small inter radial channel between them. The inner torus is only established through the centre section being clamped in place.

In the drawing the lines indicate the weld lines that will create the desired structure. Three holes, 36, are shown in the structure to allow water to pass into the sealing material, 34, these hole can be easily cut out by a knife tool at the same time as welding. More or less holes can be used as required. It is also possible to position the holes other than in the centre of the torus, such as outside of the outermost torus; in such an instance it is preferable for the extra sealing material, 34, to be sewn to the outer seam of the torus with the addition of a strip of webbing to act as the holes. When pressurised with gas the channels inflate, tensioning the fabric and thus create a ridged or semi-ridged ring. It is possible to incorporate more than two tori and more channels than is shown by figure 4 if preferred. The shape of the inter-radial channel and inner torus is not important, they merely facilitate the flow of gas or other fluid from the centre section, 30, to the outer torus. Additionally the shape of the outer torus need not be absolutely circular, an approximation of a ring will suffice; it is possible to achieve some benefits by

the use of a slightly square ring when using a woven material with a warp and weft thread.

2 1 t,

Claims

CLAIMS 1. A device for temporarily sealing a hole in a boat or other vessel that comprises: an inflatable assembly comprising one or more inflatable structures that when inflated each form a at least one ridged or semi-ridged torus shaped ring where material for sealing is supported by said torus, such that the inflated sections of the inflatable structures cannot come into direct contact with the hole space post deployment and such that the inflated sections of the inflatable structures are not used for direct structural support of said material for sealing over the hole space; a pole with the inflatable assembly at one end and a gas delivery system at the other end where gas delivery is achieved through the use of a hand pump or compressed gas cylinder, the latter being pierced by a pin through the use of appropriate means ; a protective cover that holds the inflatable structure (s) in a small pre-deployment diameter.
2. A hole sealing device as claimed in Claim I where the material for sealing is attached to the outer perimeter of the bottom most inflatable structure and where said structure comprises a hole or holes in order that water can form a buffer between the sealing material and the inflatable structure.
3. A hole sealing device as claimed in Claim 1 where the material for sealing is formed by the noninflated diaphragm stretched across the centre of the torus in the inflatable structure or structures.
4. A hole sealing device as claimed in Claim 1 where the protective cover comprises a sheath of material that is designed to open or break during activation of the gas cylinder.
5. A hole sealing device as claimed in Claim I where the bore of the pole is used as the protective cover, the inflatable structure (s) being forced out the end of the pole during activation of the device.
6. A hole sealing device as claimed in Claim I where a section in the centre of each inflatable structure is used to divert gas from the pole to the torus or tori, and where said centre section provides the ability to mount multiple inflatable structures axially along the pole.
7. A hole sealing device as claimed in Claim I where the inflatable structures are made in a two dimensional process where a minimum of two sheets of any suitable material are connected together.
8. A hole sealing device as claimed in Claim 7 where the material used is polyurethane coated nylon.