GB2038287A - Liferaft containers - Google Patents

Abstract

A container for an inflatable liferaft which comprises a rigid casing formed by at least two separable parts 13, etc., is movable by rolling about a rolling axis and is provided with replaceable resilient strips 19 which extend round the periphery of the casing so that when the container is rolled, it rolls on the resilient strips 19 which serve to hold the casing spaced from the rolling surface. Bands 23 hold the strips 19 in position. <IMAGE>

Description

SPECIFICATION Liferaft container The present invention relates to liferaft containers and is particularly concerned with a container for an inflatable liferaft which comprises a rigid casing formed by at least two separable parts which are releasably connected together to provide an enclosure for the liferaft and which are separable for release of the liferaft.

A container for an inflatable liferaft hitherto proposed has been so constructed as to be movable by rolling it about a rolling axis and the casing has been formed with peripheral ribs extending round the casing so that when the container is rolled about the rolling axis it rolls on the peripheral ribs.

The container casing is usually moulded from a glass reinforced plastics material with the ribs forming an integral part of the casing. The containers are used on ships where they are stored on racks and are usually handled by rolling on the deck for mounting on the racks and removal from the racks for regular inspection and servicing. It has been found that while the ribs provide protection for the main body of the casing during rolling, they become subject to wear and that once such wear has become serious enough as to affect the reliability of the container in use, the complete casing needs to be replaced.

It is an object of the present invention to provide a liferaft container which while having the advantages provided by the peripheral ribs of the container hitherto proposed, avoids giving rise to the need for replacement of the casing.

According to the present invention, there is provided a container for an inflatable liferaft, the container being movable by rolling about a rolling axis and comprising a rigid casing formed hy at least two separable parts which are releasably connected together to provide an enclosure for the liferaft and which are separable for release of the liferaft, and replaceable resilient means so located on the periphery of the casing that when the container is rolled about the rolling axis on a plane rolling surface, it rolls on the resilient means which holds the casing spaced from the rolling surface.

The resilient means preferably comprises a plurality of strips of resilient material extending round the periphery of the casing in a plane normal or substantially normal to the rolling axis and spaced apart on the casing in the direction of the rolling axis.

In a preferred embodiment of the invention each strip extends from one end of the strip round the casing without interruption to the other end of the strip, with the ends being brought to positions adjacent each other. Each strip is preferably placed on the container with its ends not connected together and holding means are provided for holding the strip in place on the casing.

The holding means may conveniently comprise in respect of each strip an inextensible band passing round the casing and engaging the strip and in a preferred embodiment of the invention the strip is provided with a channel formed in the outer surface thereof and extending along the length of the strip and the band is located in the channel and so recessed within the strip that the container when rolled about the rolling axis rolls on the resilient strip.

The casing may be formed with ribs extending around the casing in a plane at right angles to the rolling axis of the container, the ribs serving to restrain each strip from displacement in a direction parallel to the rolling axis and in a preferred embodiment of the invention each strip is retained by one of the ribs on one side thereof and another of the ribs on the other side thereof and the casing is so formed that the portion thereof between the ribs and supporting the strip lies above the level of the casing on the other side of the ribs.

The casing preferably comprises a cylindrical main body portion closed at each end by a hemispherical end portion. The part of the casing on one side of a dividing plane passing through the rolling axis may then form one of the two separable parts of the casing and the part of the casing on the other side of the plane then forms the other separable part of the casing. The two separable parts may be joined together along their registering edges by a sealing strip extending round the casing in the dividing plane. The ends of each strip are preferably located at one side or the other side of the casing where the separable parts are joined together.

The separable parts of the casing may be held against separation by the bands which are so weakened locally as to break on inflation of an inflatable liferaft within the casing to allow separation of the two parts of the casing under the action of the inflating liferaft.

The sealing strip may be a strip of flexible material adhered to both separable parts or a foam rubber gasket or compression gasket. Preferably, the sealing strip is of H-shaped cross-section with the registering edge of one of the two separable parts being located in one of the two grooves formed in the strip and the registering edge of the other part engaging in the other of the two grooves. The sealing strip of H-shaped cross-section, where such is used, may be compressed by a wedge lock strip to grip the edges of the parts and form a water-tight seal therebetween.

The casing may be made from a glass reinforced plastics material and each resilient strip may be made from a natural or synthetic rubber.

One embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which Figure 1 is a side elevation of a liferaft container according to the invention, Figure 2 is a scrap section of the liferaft container shown in Figure 1, taken on the line ll-ll in Figure 1, and showing a part of one side of the container, Figure 3 is a scrap section of the container shown in Figure 1, also taken on the line ll-ll in Figure 1, and showing a part of the other side of the container and, Figure 4 is a section of part of the container shown in Figure 1,taken on the line IV-IV Figure 1.

Referring first to Figure 1, the liferaft container is of generally circular cross-section and comprises a casing with a cylindrical centre portion 10 and hemispherical ends 11. The casing is divided into two parts 12 and 13 by a horizontal plane including the axis of the centre portion 10 and the parts 12 and 13 are of generally the same shape. The two parts 12 and 13 are joined together to form an enclosure for the liferaft and are made from a glass reinforced plastics material.

Referring now to Figures 2 and 3, a rubber sealing strip 14 (see Figure 3) of H-shaped cross-section joins adjacent edges 12a, of the two parts 12,13 respectively. Each edge 12a, 13a of each part 12,13 fits into one of the two grooves formed between the uprights and the cross-piece of the H-shaped crosssection. A wedge lock strip 15 extends around the sealing strip 14 and compresses the sealing strip 14 so that it grips the edges 12a, 13a of the parts 12,13 to form a water-tight seal therebetween.

Referring now to all the Figures, the two parts 12,13 of the container are provided with four pairs of parallel moulded ribs 16 and 17 which together form four channels 18 extending around the outer periphery of the casing in planes normal to the axis of the cylindrical centre portion 10 and spaced equidistantly along the centre portion 10. Each channel 18 has located therein a strip 19 of natural or synthetic rubber which extends from one of its ends 20 round the casing, without interruption, to its other end 21, the two ends being brought to positions adjacent each other as shown in Figure 2. As shown in Figure 3, the strip 19 is continuous in the region where it passes over the sealing strip 14 on the other side of the container.Each of the strips 19 is provided with a channel 22 extending along the length of the strip 19 and an inextensible band 23 is located in the channel 22 and tightened round the strip 19 by a conventional case banding method to hold the strip 19 in place in the channel 18. The four bands 23 serve also to hold the two casing parts 12 and 13 together and each band is so weakened locally by a perforation 24 as to break on inflation of an inflatable liferaft housed within the casing. As will be seen, the bands 23 are so recessed in the strips 19 thatthe container when rolled about its longitudinal axis rolls on the strips 19.

In use, a collapsed inflatable liferaft is housed in the closed container 10 together with inflation equipmentforthe liferaft. Such containers are stowed on a ship in a readily accessible position on the deck of the ship for use in emergency. The containers are mounted on racks and a guideway is provided down which the containers can roll, in use, about the longitudinal axis of the cylindrical central portion, into the sea. The containers are also rolled in this manner when they are brought to the racks and when they are removed from them for servicing.

The strips 19 carry the weight of the container 10 during such movements and reduce wear and damage to the container casing during such movements. The strips 19 can, when worn through use, be readily replaced by removing the bands 23, replacing the strips 19 with replacement strips and then securing the replacement strips with new bands 23.

In use in an emergency, the container 10 is released from a ship on which it is stowed and inflation of the liferaft initiated. This can be achieved either manually or automatically. The volume of the liferaft within the container increases as it inflates tending to force the two parts 12 and 13 apart. When the force is sufficiently great, the bands 23 snap at the points of weakness provided by the perforations 24. The two parts 12 and 13 then separate to allow the liferaftto complete its inflation and deploy in the sea.

It will be appreciated that the join between the edges 13a, 13a of the two parts 12 and 13 may be by a strip of flexible material adhered to both parts 12, 13 or by a foam rubber gasket adhered to the two parts. In addition, the metal bands 23 may be replaced by bands of rubber or of plastics material with suitable points of weakness. Alternatively, the bands 23 may be used only for securing the strips 19 and bolts provided for securing the two parts 12 and 13 together, the bolts having portions which are suitably weakened to allow separation of the parts 12 and 13 upon inflation of the liferaft within the container.

Claims (15)

1. A container for an inflatable liferaft, the container being movable by rolling about a rolling axis and comprising a rigid casing formed by at least two separable parts which are releasably connected together to provide an enclosure for the liferaft and which are separable for release of the liferaft, and replaceable resilient means so located on the periphery of the casing that when the container is rolled about the rolling axis on a plane rolling surface it rolls on the resilient means which holds the casing spaced from the rolling surface.

2. A container according to claim 1, wherein the resilient means comprises a plurality of strips of a resilient material extending round the periphery of the casing in a plane normal or substantially normal to the rolling axis and spaced apart on the casing in the direction of the rolling axis.

3. A container according to claim 2, wherein each strip extends from one end of the strip round the casing without interruption to the other end of the strip with the ends being brought to positions adjacent each other.

4. A container according to claim 3, wherein the ends of each strip are not connected together and the container further comprises holding means for holding the strip in place on the casing.

5. A container according to claim 4, wherein the holding means comprises in respect of each strip an inextensible band passing round the casing and engaging the strip.

6. A container according to claim 5, wherein each strip is provided with a channel formed in its outer surface and extending along the length of the strip and wherein the band is located in the channel and so recessed within the strip that the container when rolled about the rolling axis rolls on the resilient strip.

7. A container according to any of claims 2 to 6, wherein the casing is formed with ribs extending round the casing in a plane at right angles to the rolling axis of the container, the ribs serving to restrain each strip from displacement in a direction parallel to the rolling axis.

8. A container according to claim 7, wherein each strip is restrained by one of the ribs on one side thereof and another of the ribs on the other side thereof and wherein the casing is so formed that the portion thereof between the ribs and supporting the strip lies above the level of the casing on the other side of the ribs.

9. A container according to any of the preceding claims, wherein the casing is formed as a surface of revolution about the rolling axis.

10. A container according to claim 9, wherein the casing comprises a cylindrical main body portion closed at each end by a hemispherical end portion.

11. A container according to any of the preceding claims, wherein the part of the casing on one side of a dividing plane passing through the rolling axis forms one of the two separable parts of the casing and the part of the casing on the other side of the plane forms the other separable part of the casing.

12. A container according to claim 11, wherein the two separable parts are joined together along registering edges by a sealing strip extending round the casing in the dividing plane.

13. A container according to claim 12, wherein the adjacent ends of each strip are located at one side or the other side of the casing where the separable parts are joined together.

14. A container according to claim 5, or any of claims 6 to 13 appendentto claim 5, wherein the separable parts of the casing are held against separation by the bands which are so weakend locally as to break on inflation of an inflatable liferaft within the casing to allow separation of the two parts of the casing under the action of the inflating liferaft.

15. A container for an inflatable liferaft substantially as hereinbefore described with reference to the accompanying drawings.