GB2171069A - Inflatable life raft with improved water filled capsizing prevention bag arrangement - Google Patents

Abstract

The life raft consists of a peripheral floatation tube (1) and a base (9) under which is mounted a ring of bags (10) that fill with water to stabilise the raft. Tie bars (2) are provided between adjacent bags (10) and are provided at both ends with straps (3,4). The straps 3 are connected by bands (11) to the adjacent bags (10). Cords (6) and elastic bands (5) are affixed to the straps (4), the cords (6) being attached to the supporting tube (1) by detachable fasteners (8) and the bands (5) being attached to the base (9). The bands (11) and the bags (10) form a closed ring underneath the supporting tubes (1). The tie bars (2) when in the erect position shown hold the bags (10) open to fill with water. However on release of the fastener (8), the bars are moved by elastic bands (5) to a stowage position in which individual bags can be folded flat against the base (9). <IMAGE>

Description

SPECIFICATION Inflatable life raft with improved water filled capsizing prevention bag arrangement.

The invention relates to a life raft provided with bags to be filled with water to prevent the raft from capsizing in high sea conditions.

A number of methods are known for preventing inflatable life rafts from capsizing, most of them based on the provision, on the bottom of the raft, of bags which fill with water after immersion. The water filled bags prevent capsizing when they are lifted out of the water with part of the raft by high waves or during boarding.

DDR Unexamd.Specn. 28 30 748 discloses a raft with such bags and having a closed ring system containing weights which draw the bases of the bags downwards, thus accelerating the water filling process. Drawbacks of this known raft are firstly that the weights increase the overall depth of the raft, and secondly that the sinking of the weights is opposed by buoyancy in the water, so that the filling process is still comparatively slow involving a risk of capsizing when the life raft has just been placed in the water and inflated.

The aforementioned drawbacks are avoided by the raft described in DDR Unexamd.Specn.

24 37 755. For this raft, a water receiving bag is clamped by two bars which are affixed to the floatation tube of the life raft in such a way that the distance between the free ends of the bars, in the unloaded state, is greater than the distance between the secured ends.

A bag clamped in this way during the raft inflation rapidly fills with water and proves suitable as a means of preventing capsizing.

The drawback of this solution mainly resides in the way in which the bars are affixed. If a side current occurs the bars are liable to give way in one direction, resulting in partial collapse of the bag which leads to a reduction in volume and reduces the stability and non capsizing properties of the raft. The risk of partial collapse of the bag also occurs when a sea current impinges on the surface of the bag from the front. The bars, owing to the way in which they are affixed, are in any case subjected to bending stresses, so that the bag is no longer rigidly stretched by the bars. The bending is aggravated by the fact that the bars are affixed half way up the supporting tube and thus have to be relatively long in order to obtain the desired effect. The length of the bars, moreover, hinders the packing of the raft.

The production cost of the bags increases, because they need to be specially formed for connection to the bars. A further drawback resides in the fact that the bars are permanently erected during raft inflation, and this proves a major obtstacle.for maintenance of the raft, which to some extent has to be carried out while it is inflated.

Broadly stated, the invention provides an inflatable life raft including inflatable floatation means on a base which has on the underside thereof a plurality of bags to be filled with water to stabilise the raft, the bags being arranged in a ring, a plurality of rigid members arranged between the bags and connected thereto, said members also being connected to the base in such a manner as to be selectively operable to and from a stowage position whereat the bags can be folded against the base, and an erect position whereat the members depend downwardly from the base for filling the bags with water.

Preferably, said rigid members are connected to the base through resilient means, and including means for selectively tensioning said resilient means to move said rigid members between said stowage and erect positions.

An object of the present invention is to develop a life raft provided with a device for the prevention of capsizing, with bags designed to receive water and with tie bars which are to be arranged and connected in such a manner that the bags are automatically stabilized on the closed loop or ring principle, while this stabilization, while the raft is in the inflated state, can if necessary be temporarily nullified for maintenance purposes. More specifically, the object is to combine low production cost with outstanding non-capsizing properties and a high degree of stability and to ensure that the manufacture and maintenance of the raft will not be impeded by the device for preventing capsizing.

The invention achieves this object in a preferred embodiment as a result of the fact that the rigid members comprise tie bars which are in each case situated between adjacent bags and provided with straps at both ends. In each case one strap is connected via bands to the adjacent bags. Cords passing through associated eyes and also tensionally elastic bands are provied on the opposite straps. The eyes and the elastic bands are affixed to the base, while the cords are connected with a supporting floatation tube by a detachable fastening. The bands and the bags form a closed ring underneath the supporting tubes.

It is possible for the tie bars, to the left and right of a boarding point, to be connected solely by one continuous band to the straps which are provided for the connection to the bags.

The bands may also continue in each case over the entire length of the bags and be connected to the latter.

On the inflation of the life raft the tie bags and the bags are erected, since owing to the fact that the cords have been secured beforehand in the detachable fastenings on the supporting tube the position of the tie bars is fixed. This ensures the very rapid filling of the bags with water, the raft thus being prevented from capsizing. Due to the ring created by bands and bags and also to the way in which the tie bars are arranged, a system is produced which is stabilized on a closed loop principle and substantially overcomes the effects of sea currents or other influences. The production and maintenance of the system are simple by comparison with other solutions and the individual elements can be removed and replaced with very little effort. By comparison with the prior weighted systems, the present invention provides a substantial improvement.

Rigidification, when the raft is in the inflated state, can be easily nullified by actuating the releasable fastening of the cords to the supporting tubes. This possibility proves an advantage from the point of view of manufacture and maintenance.

Fewer bars are required than in systems for the prevention of capsizing having bars inside the actual stabilizing bag.

The invention will be explained below in greater detail by reference to an example shown in the accompanying drawings wherein: Figure 1 is a perspective view of part of a life raft, with a device for the prevention of capsizing, in accordance with -the invention, and Figure 2 is a section between two bags shown in Fig. 1.

As shown in Fig. 1 the inflatable life raft comprises an inflatable floatation ring or tube 1 which extends around the periphery of a flexible fabric base 9. On the underside of the base 9 is provided a ring of bags 10 to be filled with water to stabilise the raft against capsizing. Between adjacent bags 10 are arranged erectable tie bags 2 which are movable from a stowage position lying against the base, in which the bags 10 can be folded against the base, to the erect position (shown in Figs. 1 and 2) for causing the bags 10 to fill with water.

Upon inflation of the raft, the tube 1 stretches the base 9 tight. As shown in Fig. 2 each tie bar is provided at opposite ends with straps 3 and 4. The strap 3 is connected by bands 11 to adjacent ones of the rings. The strap 4 is connected to an arrangement which allows the tie bar to be moved selectively between the erect position shown in the drawings and a position in which the bags may be de-rigidified and folded against the base 9.

To this end, each strap 4 is connected to an elastic strap or band 5 which is held by a securing device 7 on the base. As shown in Fig. 2, in the erect position, the band 5 is held in a stretched condition by a cord 6 attached to the band 4, which runs through a eye 14 and is held by a releasable pressbutton fastening device 8.

The position of the eyes 14 on the base 9 is selected to ensure that they form a stop for the tie bars 2 and the straps 4 and prevent the said tie bars 2 from being deflected laterally.

By releasing the fastening devices 8 the tie bars 2 are released and drawn towards the securing devices 7 by the elastic bands 5.

The tie bars 2 are thus caused to come to rest against the base 9, are protected from damage and do not prove a hindrance, e.g. to maintenance operations carried out on the life raft.

Filling apertures 13 in the form of flap valves and vents 12 are provided for the purpose of filling the bags 10 with water.

At the boarding point no bag 10 is provided, so that the adjacent tie bars 2 are only interconnected by a band 11.

The bands 11 can continue the whole way and can be attached to the bags 10 over the entire length of the latter.

The oblique position of the tie bars 2 guarantees maximum stability. The geometry of the whole system is so designed that its stabilization is effected almost entirely by positive engagement.

Claims (7)

1. An inflatable life raft including inflatable floatation means on a base which has on the underside thereof a plurality of bags to be filled with water to stabilise the raft, the bags being arranged in a ring, a plurality of rigid members arranged between the bags and connected thereto, said members also being connected to the base in such a manner as to be selectively operable to and from a stowage position whereat the bags can be folded against the base and an erect position whereat the members depend downwardly from the base for filling the bags with water.

2. An inflatable life raft according to claim 1 wherein said rigid members are connected to the base through resilient means, and including means for selectively tensioning said resilient means to move said rigid members between said stowage and erect positions.

3. An inflatable life raft according to claim 1 or 2 wherein said rigid members comprise tie bars each connected at one end thereof to adjacent ones of the bags, and each connected at the other end thereof to an elastic member connected to the base and urging the bar to said stowage position, and a cord connected to the tie bar and to the raft to hold the bar against the elastic force of said elastic member and in said erect position.

4. An inflatable life raft according to claim 3 having a boarding point beneath which no said bag is disposed, the tie bars on opposite sides of the boarding point being interconnected by cord at the ends thereof remote from the base.

5. An inflatable life raft according to claim 3 or 4 wherein the ends of the tie bars remotest from the base are interconnected by con tinuous cords to which the bags are attached along the entire length thereof.

6. A device to prevent inflatable life rafts from capsizing, with bags designed to receive water and mounted along a supporting floatation tube and with tie bars, characterized by the fact that tie bars are in each case present between adjacent bags and provided with straps both ends, the straps at one end being connected via bands with the adjacent bags and the straps the other end being connected to cords affixed to base, the cords being connected to the supporting tube by a detachable fastening and tensionable elastic bands, affixed to the base 9, are provided on the straps, the bands and the bags forming a closed ring underneath the supporting tube.

7. An inflatable life raft substantially as herein described with reference to the accompanying drawings.