GB2094236A

GB2094236A - Improved liferaft stabilising pocket

Info

Publication number: GB2094236A
Application number: GB8205657A
Authority: GB
Original assignee: Lifeguard Equipment Ltd
Current assignee: Lifeguard Equipment Ltd
Priority date: 1981-02-27
Filing date: 1982-02-26
Publication date: 1982-09-15

Abstract

A stabilising pocket for an inflatable liferaft comprising a collapsible casing, rectangular as illustrated. In order to ensure rapid filling of the pocket with water on inflation of the raft large apertures 15, are provided in the casing adjacent the underside of the liferaft and further large apertures 19 are provided remote from the apertures 15 and adjacent a lowermost end portion of the pocket. The apertures 19 have associated therewith a oneway valve, in the form of a flap 23 for impeding the flow of water out of the pocket. <IMAGE>

Description

SPECIFICATION Improved liferaft stabilising pocket The present invention reiates to an improved stabilising pocket for an inflatable liferaft.

The type of stabilising pocket in general use on inflatable liferafts is a rectangular boxshaped bag, manufactured from a coated textile which allows it to fold with the uniflated liferaft in its container. The liferaft may have one or more stabilising pockets, the number being dependent upon the size of the liferaft and the section of the liferaft requiring ballast in the form of water contained in the pocket.

Water enters these known pockets through open apertures in the upper parts of the side walls of the pocket. Small apertures may also be provided at or adjacent the bottom of the pocket for slow draingage purposes by personell lifting the liferaft out of the water.

As a consequence of the liferaft and the pocket being stowed in tightly folded state for a considerable period, when applied to its purpose and the liferaft is inflated at sea, the pocket or pockets fail to fill quickly with water.

It has been proposed to introduce blocks of open cell foam into the pocket, this helps to prevent water being pumped out of the pocket by wave action but filling of the pocket is little improved because of the constraints applied to the foam by the folded material.

The stabilising pocket serves to prevent lifting of the liferaft by wind or wave action and it is important that the pocket should fill quickly but drain only slowly or not at all if it is to be most effective.

An object of the invention is to provide an improved stabilising pocket which fills more quickly than the known stabilising pockets and which provides an improved stabilising performance.

According to the present invention there is provided a liferaft stabilising pocket comprising a collapsible casing, made of flexible ma trial, for attachment to the underside of a liferaft which is submerged, the walls of the casing having at least one open aperture therein disposed adjacent the underside of the liferaft and at least one further aperture located remote from the said open aperture, said further aperture having associated therewith a one-way valve which allows water to enter the casing whilst impeding flow in the reverse direction.

In a preferred embodiment of the invention the casing is rectangular and the one-way valve comprises a flap of flexible material secured to the inside of the casing and adapted to cover the said further aperture.

The present invention will now be described further, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a simplified view of one embodiment of the invention, and Figure 2 is a sectional view showing one half of the pocket of Fig. 1.

The stabilizing pocket (1) illustrated in the drawings is intended to be secured to the underside (3) of an inflatable liferaft (5) (not further illustrated). In the illustrated embodiment the pocket (1) comprises a rectangular casing having two end walls (7, 9,), two side walls, only one of which (11) is shown, and a base wall (13). The casing is made of a flexible material and the uppermost edge (17) of the end and side walls is secured to the underside (3) of the liferaft. Three open apertures (15) are provided in each side wall (11) at a region adjacent to the uppermost edge the function of which will be explained further hereinafter. Each side wall (11) also has three further apertures (1 9) which are located adjacent to the base wall (1 3) of the pocket.A rectangular flap (21) of textile material is secured to the side wall (11) along one edge (23), and serves as a one-way valve.

Upon inflation of the liferaft at sea, water enters quickly through the lowermost apertures (19) and the enclosed air is expelled from the uppermost apertures (15). If the liferaft is lifted from the surface by wind or wave the weight of water acts on the flap (21) so as to close-off the apertures (19) with the result that the water is retained in the pocket.

This gives rise to improved stabilisation.

The known stabilising pocket fills from the top, and filling is achieved only slowly.

Preferably, the flap is made from a fabric similar to that of the pocket for example a coated flexible material. In an improvement the lower section ofthe pocket, preferably the base wall (13) is weighed with a small amount of ballast (25) in the form of lead shot.

The number of open apertures (15) and the number of closeable apertures (19) may be varied depending on the size of the pocket, at least one of each being provided in the pocket. Likewise, apertures with valve flaps can be located in the lower part of any of the 4 walls OR/AND in the base. Where more than one closeable aperture (19) is provided, an individual flap (23) may be used for each aperture (19) or one flap may serve to close all the apertures (19).

In an alternative emobodiment only two opposing edges of the uppermost edge (17) of the casing are secured to the underside of the inflatable liferaft (5). Thus for example the upper edge of the two end walls may be secured to the underside of the liferaft and the upper edge of the two sides may be left unsecured so that the opening therebetween serves as an aperture allowing the venting of air on filling of the pocket.

The flap or flaps serving as a one way valve may be rectangular and secured along the two longitudinal edges, or alternatively along one longitudinal edge and two transverse edges in order to locate the flap more positively and prevent it from lifting when the pocket is filled with water.

In an alternative embodiment the one way valve may take the form of an open ended tube of collapsible material which surrounds the aperture (19) and which extends into the pocket and which collapses when water attempts to flow out of the pocket.

A further application is a continuous stabilising pocket around the peripheral underside of the raft, which may for example be subdivided into compartments each with a valved inlet and an outlet facility as described.

The stabilising pocket or pockets may be attached to the floor of the liferaft or to the buoyancy tube.

Claims

1. A liferaft stabilising pocket, which comprises a collapsible casing, made of flexible material, for attachment to the underside of a liferaft which is submerged, the walls of the casing having at least one open aperture therein disposed adjacent the underside of the liferaft and at least one further aperture located remote from said open aperture, said further aperture having associated therewith a oneway valve which allows water to enter the casing whilst impeding flow in the reverse direction.

2. A liferaft stabilising pocket as claimed in claim 1, wherein the oneway valve comprises a flap of flexible material secured to the inside of the casing and adapted to cover said further aperture.

3. A liferaft stabilising pocket as claimed in claim 2, wherein, the flap is made from a coated flexible material.

4. A liferaft stabilising pocket as claimed in claim 1, wherein the oneway valve comprises as open-ended tube of collapsible material which surrounds said further aperture and which will collapse when water attempts to flow out of the pocket.

5. A liferaft stabilising pocket as claimed in any of claims 1 to 4, wherein the casing is rectangular.

6. A liferaft stabilising pocket as claimed in claim 5, wherein the casing comprises two side walls, two end walls and a base wall, and wherein three of said open apertures are provided in each of said side walls adjacent the uppermost edge of each of said side walls.

7. A liferaft stabilising pocket as claimed in claim 5 or claim 6, wherein the casing comprises two side walls, two end walls and a base wall, and wherein three of said further apertures are located in each of said side walls adjacent to the base wall.

8. A liferaft stabilising pocket as claimed in any of claims 1 to 7, wherein said collapsible casing is made from a coated flexible material.

9. A liferaft stabilising pocket as claimed in claim 1 and substantially as hereinbefore described with reference to the accompanying drawings.