WO1998033702A1

WO1998033702A1 - A device for quickly increasing the buoyancy of boats

Info

Publication number: WO1998033702A1
Application number: PCT/NO1997/000026
Authority: WO
Inventors: Kaare Haahjem
Original assignee: Patos As
Priority date: 1995-08-03
Filing date: 1997-01-31
Publication date: 1998-08-06
Also published as: NO953047L; NO953047D0; NO300624B1

Abstract

Device for quickly increasing the buoyancy of boats, where lifting pads (12-15) are used that are placed in cavities in the boat or outside on the boat hull. The lifting pads are connected to a supply line or a supply network for supplying a medium that can contribute to the inflation of the bags. They are designed with double walls, forming a central expansion room (18) and a surrounding shell-shaped room (19) that covers at least a considerable part of the central expansion room. The surrounding shell-shaped room (19) is intended for filling with a hardening material. These lifting bags may also be used for making life rafts.

Description

A DEVICE FOR QUICKLY INCREASING THE BUOYANCY OF BOATS

The present invention relates to a device for quickly increasing the buoyancy of boats as indicated in the introduction of claim 1.

Background

A number of attempts has been made to develop devices that can be used m order to increase the buoyancy of both small and larger vessels in an emergency situation.

From the French publication 2,511,645 it is known to supply a part of a boat hull with a rapid hardening foam material that form a rigid and waterproof buoyancy body. In order to delimit such a buoyancy body from other parts of the hull or cavities in the hull, it is suggested in this publication to use a membrane that either is fixed, or can be drawn into place, m order to close off a space in the vessel. However, this solution is not worth while for different reasons, e.g. because it requires manual operation and because the foam easily could cause damage or have unfortunate effects when getting into contact with the exposed parts of the hull space.

From the British publication 2,044.183 t is known to place empty air pads in different boat hull positions and fill these air pads with pressurized air by remote controlled valves in an emergency situation. With this solution, some of the drawbacks of the aforementioned device are avoided, but at the same t me other drawback are introduced. This solution requires i.e. a supply system comprising pressurized air lines to the various spaces. The empty air pads, which in principle must be exposed, will also limit the utility of the space, in addition to not being very esthetic.

Objects of the invention

The main object of the present invention is to find a rescue system that is able to save both the crew and vessel in a situation where a boat is taking in water, and where there is a risk that the boat will go down.

The present invention aims especially at finding a device that removes all the drawbacks in connection with the two aforementioned solutions and other known solutions, where a boat space, or part of a boat space, is filled with a liquid, light medium in an emergency situation.

Particularly, it is an object to find a device w th buoyancy means that are sufficient both during normal operation and in an emergency situation. This also means that a device is desired where the buoyancy means are as invisible and inaccessible as possible during normal operation, while still forming effective and reliable buoyancy means in a emergency situation.

Summary of the invention

In accordance with the invention, these objects can be fulfilled by a device of the kind indicated in claim 1.

With regard to use of fabric air pads, as e.g. used m the British patent application 2,044,183, the present invention implies that the fabric material can be given reduced thickness and strength compared to known air pad solutions, and yet provide greater security against tearing and other failures. Thus, the false feeling of secu- rity, often present in the case with known solutions, has been removed. At the same time a foam material can be used without the risk of pollution and damage on fixtures .

Further features of the invention are indicated in the subordinate claims.

Brief description of the drawings The invention is in the following described with reference to the figures, where:

Fig. 1 and 2 show schematic longitudinal sections of a vessel with lifting pads m a folded and inflated state, respectively,

Fig. 3-10 show schematic cross sections of four different vessels, with various embodiments of the present invention, shown in a stand-by and inflated state, respec- tively,

Fig. 11A-C show a side view, a longitudinal section, and a cross section of a floating body according to the invention,

Detailed description

In Fig. 1 and 2 a vessel, e.g. a fishing boat or pleasure craft with a superstructure, is schematically shown. In this boat four buoyancy bodies 12, in the following called lifting pads, are drawn internally at the bottom of the boat. The design and use of these will be described in detail m the following. A lifting pad 13 is placed in a space by bow of the vessel 11 and likewise a lifting pad 14 is placed by the stern. As will appear from the following description, the shape of the lifting pads 12-14 are adapted to the space in places of the vessel that normally cannot be completely utilized for cargo and passenger space.

Fig. 2 shows how the lifting pads 13 and 14 are expanded to an active state in order to form buoyancy bodies that can keep the vessel afloat in case it should start to leak, e.g. because of collision or because of other forms of damage to the hull.

In Fig. 11A-C an example of such a lifting pad is shown, in this case shaped as an elongated "sausage" 15. The lifting pad 15 has an inner casing 16 and a outer casing 17 with a corresponding shape, so that they in a expanded state form a body with a inner cavity 18 and a space between the two casings 16 and 17 that form a shell space 19. This can be obtained by air being led into the inner cavity 18 through a supply space 20, while a expanding plastic mass is being led through a supply line 21. The supply systems will be described in detail in the following.

Longitudinal connecting walls 22 may be placed lengthwise between the two casings 16 and 17, in the present example four connecting walls arranged around the circumference (Fig. 11C) , or corresponding ring walls that also stretch radially. The connecting walls 22 are preferably perforated by holes 23 for penetration of the filling mass 24.

The lifting pad 15 is folded together while in stand-by, in a manner shown schematically in Fig. 1. Air is sup- plied from an external storage tank, e.g. a pressurized air tank, through the supply line 20 to the inner cavity 18, in order for the cavity to expand to its maximal size. The control of this air supply may take place in a known manner, by manual actuation or actuation by some kind of remote control.

Concurrently with or after the inflation of the inner casing 16, buoyancy material is supplied also to the double wall 19. In the example, a plastic material that foams up due to the supply of a foaming agent is used, e.g. a liquid polymer material. A polyurethane compound that can be stored as a liquid or viscous substance in a closed container and can be pushed out by a propellant, e.g. a suitable gas, in order for it to expand by contact with air or the propellant gas, can be used. After the foaming, the plastic mass will harden to a comparatively rigid shell with a thickness corresponding to the double wall 19. This shell will by it self have buoyancy and also protect the inner casing 16 against stresses that otherwise could have opened the inner cavity 18.

The stand-by storage of air and foam material can either be done locally by the individual floating bodies 12-14, in amounts that are suitable for the volume that is going to be filled, with remote controlled actuation of valves (not shown) , or centrally with pipe or tube connections to the individual lifting pads in the vessel. In an emergency situation, where the vessel having such equipment is taking in water, a simple hand operation can open the supply of air and foam to the lifting pads. The filling system is preferably arranged in such a manner that it is possible to fill the lifting pads in a part of the vessel without actuating the lifting pads in the rest of the vessel. The casings 16 and 17 can be made of a reinforced plastic material, coated fabric material or other pliable and possibly flexible material.

At each end of the sausage shaped lifting pad 15, protruding lugs are arranged with fastening holes 25A, in a shape that principally are known from buoys, fender elements etc. The purpose of this will become clear from the description below.

In Fig. 3 and 4, a cross section through a boat with lifting pads 26 placed under sitting benches or similar spaces, in a stand-by and an active, expanded state, respectively.

In Fig. 5 and 6, corresponding situations are shown for lifting pads 27 that are placed in pairs under the vessel, one on each side of the keel, the lifting pads having a drop shaped cross section with the tip pointing to- wards the keel. This means that the lifting pads 27, after the expansion, will lie under the bottom of the vessel with the outer and widest end near the transition to the sides of the vessel.

In Fig. 7 and 8, lifting pads 28 corresponding to those in Fig. 3 and 4 are shown, but instead fixed to the underside of the deck in pairs in a cargo room, one on each side of a hatch.

Correspondingly, in Fig. 9 and 10, a central lifting bag 29 is placed centrally in the vessel, at the bottom of its cargo room, in a manner such that it can expand and take up a considerable portion of the cargo room. In this case the lifting pad 29 is folded together in the stand-by state (Fig. 9) in order to take up a small vol- ume compared to the final volume. The foam mass supply inlet is in this case at the underside.

The dimensioning of the bags and the materials used therein must be adapted to the particular application and the materials used. In one embodiment the foam thickness, i.e. the thickness of the double wall 19, may be about 10% of the thickness of the pads.

A foam material that hardens and forms a rigid shell after a certain hardening time can be chosen, but it is also possible to use a foam material that remains more flexible, even if this reduces the protection effect.

A number of foam types exist, e.g. polyurethane, with a large expanding ability and long storage capability in the liquid state, ready for use. Polyurethane works best in the temperature range 10-30°C, but can function down to -5°C. UP-E -unsaturated polyester or expanded, is another versatile compound.

The invention makes it possible to use expanded lifting pads as floating bodies for lifesaving at sea. This can be obtained by removing excess lifting pads from the ves- sel in an emergency situation, or by storing an excess of lifting pads that are freely accessible for expansion and (use) . With lifting bags as shown in Fig. 11, it is possible to connect several units to a life raft. The invention makes it possible to have buoyancy elements of comparatively thin and inexpensive materials at stand-by, which in an emergency situation can be transformed to an expanded state with sufficient strength to sustain those strains that can be expected, at least in connection with emergency situations for pleasure crafts.

Claims

C l a i m s

1. A device for quickly increasing the buoyancy of boats, where lifting pads (12-15) are used that are placed in cavities in the boat or outside on the boat hull, where the lifting pads are connected to a supply line or a supply network for supplying of a medium, such as air, that can contribute to inflation of the bags, c h a r a c t e r i z e d in that the lifting pads (15) are designed with double walls, forming a central expansion room (18) and a surrounding shell-shaped room (19) that covers at least a considerable part of the central expansion room, where the surrounding shell-shaped room (19) is intended for filling with a hardening foam mate- rial.

2. A device according to claim 1, c h a r a c t e r i z e d in that the two rooms are formed by to casings (16, 17) made of pliable, fabric- like material, which is arranged in a generally concentric fashion, with connection walls (22) that preferably are perforated for penetration of a foam material, or closed for forming separated air chambers.

3. A device according to claim 1, c h a r a c t e r i z e d in that the lifting pads (12- 14) are placed in such a manner during stand-by storage that the supply opening for the foam material is on the underside .

4. A device according to claim 1-3, c h a r a c t e r i z e d in that the lifting pads (15) are supplied with at least one connecting body (24, 25), especially for interconnection of several separate lift- ing pads.

5. A device according to claim 4, c h a r a c t e r i z e d in that the lifting pads (15) are sausage shaped and provided with a connecting body (25) at each end, for the interconnection of three or more lifting pads in a polygon structure for a carrying system for a life raft (32-34) .