GB2569860A

GB2569860A - A dual bladder life jacket

Info

Publication number: GB2569860A
Application number: GB1817736.0A
Authority: GB
Inventors: Nigel Dale Jeremy
Original assignee: Individual
Current assignee: Individual
Priority date: 2017-10-31
Filing date: 2018-10-30
Publication date: 2019-07-03
Anticipated expiration: 2038-10-30
Also published as: GB201817736D0; GB2569860B; GB201717982D0

Abstract

An inflatable life jacket including first and second bladders 15, 25, each bladder having its own inflation means 17, where the first bladder comprises a single surface of material conjoined to the second bladder to share a common wall. Preferably the first bladder is designed to provide 150N of buoyancy when inflated, whilst when both are inflated, the life jacket provides 275N of buoyancy. Preferably the second bladder is formed by RF welding together two sheets of material, and the first bladder is then formed by welding a single sheet to the second bladder. In some embodiments, the first bladder is smaller the second, and is located about the perimeter of the second bladder.

Description

A dual bladder life jacket

The present invention relates to a dual bladder life jacket.

Life jackets are desirable, if not essential, when travelling or operating near water. There are British and International Standards associated with life jackets. A typical adult requires approximately 30 Newtons of buoyancy to float which is not that great but understandable given that a human can be as much as 70% water and so naturally buoyant.

A life jacket is intended to save lives. Accordingly, a 50N life jacket might be sufficient for a large adult who is conscious in calm waters and who adopts floating on their back and remains calm with arms by the side. However, life jackets are also expected to save lives in turbulent seas with either a panicking person or an unconscious person where it is desirable to ensure that the person is turned onto their back with the airways clear and so might be able to breathe.

Life jackets are thus classified according to their ability to save lives in mild or extreme conditions and depend upon the weight of the user. Typically, these are classified into 50N, 100N, 150N, 275N and even greater for Safety Of Life At Sea (SOLAS) use.

A user will select a life jacket from one of these classifications depending upon their weight, what they might be wearing and where they are likely to be needed i.e. offshore in rough weather or a calm inland lake.

A life jacket consists of an outer cover and waist belt, sometimes with crotch strap. The life jacket contains an inflatable bladder or lung which when required contains the ability to fill with gas, inflate and become buoyant; preferably for a long period of time. At other times it is worn deflated and in theory, close to the body.

The life jackets can inflate with gas from a cylinder, either through automatic inflation which is activated when in contact with, or submerged under, water and/or manual inflation. Manual inflation of a life jacket means that it will only inflate on demand when the manual pull cord is pulled. This pulling motion detaches a clip on the mechanism which breaks and activates the gas bottle, releasing the CO2 gas which then inflates the lung.

In both cases, automatic or manual, for an inflatable life jacket there is also the option of oral inflation through blowing into a tube and the air passes into the bladder or lung; thus inflating the life jacket.

It is also known that life jackets can be incorporated into clothing and are not separate from gilets and jackets. None the less, the arrangement and operation of the inflatable life jacket is the same.

Comfort and fit are essential when wearing a life jacket and this includes the differences in bulk and weight between the various classes of life jackets. For example the 275N life jacket can be almost twice the weight of a 150N life jacket and considerably bulkier.

Whilst many persons have their own life jackets, such are worn on the basis of the most likely scenarios encountered. In addition, boat or leisure operators may provide, or rent separately, life jackets to users and such are again often provided on the basis of most likely variables encountered. Accordingly, there are many occasions when users are expected to rely upon life jackets which are not optimum for the circumstances either too little or too much buoyancy.

In the prior art, attempts have been made to obviate this problem and reference is made to W003/009901A. This prior art is typical in providing more than one bladder for a life jacket, principally to overcome the possibility of one of the bladders being punctured or damaged. In this prior art, there is a duplication of the bladder but using the same inflation means. This life jacket is thus very bulky and cumbersome which can become dangerous to wear in some conditions.

It is thus an aim of the present invention to provide a dual bladder life jacket which overcomes the problems of the prior art by having a single surface of one of the bladders conjoined to the other bladder to share a common wall.

According to the present invention there is provided an inflatable life jacket including a first bladder and a second bladder, each respective bladder having inflation means for inflating each bladder separately, wherein said first bladder comprises a single surface of material conjoined to the second bladder to share a common wall.

The same life jacket can thus be used by a greater number of users across a greater number of scenarios yet provide a far greater likelihood for optimum buoyancy.

Preferably, said second bladder comprises two surfaces of material welded at the perimeter. It is also preferred that said first bladder is smaller than the second bladder.

The present invention is described with reference to the following drawings of which:

Figure 1 is a schematic diagram of an inflatable life jacket;

Figure 2 is a schematic diagram of a top layer and a bottom layer of an inflatable life jacket; Figure 3 is a schematic diagram of a life jacket with the top and bottom layers partially parted to expose a lung or bladder;

Figure 4 is a schematic diagram of a lung or bladder;

Figure 5 is a schematic diagram of a first and second bladder before and after inflation means are attached;

Figure 6 is a schematic cross section of the alternative arrangements of the first and second bladder;

Figure 7 is a schematic cross section of the first and second bladder according to a preferred embodiment with automatic and manual inflation means; and

Figure 8 is a schematic cross section of the first and second bladder according to a preferred embodiment with only the first bladder inflated.

As shown in the figures, a typical lifejacket 1 is in a horse-shoe shape with back straps 3 and a belt 5 to go around the waist of a user. There is a top layer 7 and bottom layer 9 connected together by way of a first seal or zip 11 along the outer periphery and a second seal or zip 13 along the inner periphery. In between the top layer 7 and bottom layer 9 there is at least one bladder 15. The bladder 15 is inflated using gas from a gas cylinder 17 and/or through an oral inflation tube 19.

The gas in the gas cylinder is released when a seal 21 is activated. The seal can be formed in a number of ways including a cap and pin with a screw spring and piston arrangement. Paper is wrapped around the piston which disintegrates when in contact with water allowing the spring to act on the pin to pierce the cap of the cylinder and release the gas. Alternatively, the cylinder has a plastic bobbin and inside the bobbin there is a powder or salt which at least loses strength or dissolves when in contact with water thus allowing the bobbin to release the pin, which pierces the cap and so the gas is released from the cylinder. A further alternative is the use of a seal which is hydro-static and so activates under the greater pressure when submerged.

There is also a manual release on a toggle 23 for manually activating the gas to be released should the seal not activate or when there is no seal.

In the present invention there is not one but two bladders 15, 25. The two bladders are conjoined like Siamese twins having a common wall forming part of both of the bladders.

Each bladder is formed from a fabric or material which is flexible. The first bladder is formed from one surface of fabric welded to at least part of one of the surfaces of the second bladder so that each bladder shares the common wall.

In the preferred embodiment, the first bladder 15 is of a smaller size than the second bladder 25 and in which case the common wall is smaller than the surface of the second bladder but the same size of the surface for the first bladder. In some circumstances the bladders could be the same size and in which case the common wall is coterminous with the surfaces of the first and second bladder.

In the preferred embodiment, the second bladder 25 is formed from two pieces of fabric or material which are welded together along the perimeter 27. In construction, the first bladder 15 is formed first from a single piece of fabric or material which is welded to one of the pieces of material for the second bladder 25 so as to share the common wall. The perimeter 29 of the first bladder is welded to leave a flange 31 on the piece of material for the second bladder. Thus, the common wall is defined by the perimeter 29. If the first bladder is formed external to the second bladder, then the common wall is internal to both bladders. If the first bladder is formed internal to the second bladder, then the common wall is external to both bladders.

It is possible in some circumstances, that the first bladder is welded to the piece of material for the second bladder but not along the perimeter 29. In any case, the pieces of material for the second bladder 25 are then welded together at the perimeter 27.

The term welded extends to any form of joining such that it provides an air tight seal and includes fusing through heat and/or gluing. In a preferred embodiment the pieces are subject to radio frequency welding (RF welding).

An oral inflation tube 19 is provided for each bladder; either on either side of the life jacket or both on the front or back of the life jacket 1. In a preferred embodiment, both oral inflation tubes are located on the front of the life jacket.

Various options are available for inflating each bladder either automatically or manually.

As shown in figure 5, first bladder 15 has a gas cylinder 17 with a seal and manual release 23 coupled thereto. Thus, the first bladder inflates automatically but maybe manually operated.

In addition, second bladder 25 is provided with a gas cylinder 17 with a seal and manual release 23 (not shown).

Alternatively, one of the bladders, either the first 15 or second 25, may be provided only with a gas cylinder 17 and manual release 23.

Another variation is that both bladders are provided only with a gas cylinder and manual release 23.

Typically a 33g or 38g gas cylinder is used and sometimes a 60g gas cylinder. The industry standard recommends that the bladder, irrespective of a single or double bladder, is inflated to less than 24131 Pa (3.5 psi) and in the preferred embodiment less than 13789 Pa (2 psi). Depending upon the application, one of the variations above is selected and the type of gas cylinder. Thus in some circumstances, the oral inflation tube or tubes require in addition a pressure release valve (not shown) to ensure that the bladders only inflate to the recommended pressure.

In practice, should a user need to rely on the life jacket according to the present invention, the automatic or manual inflation into one of the bladders would occur. If the user requires greater buoyancy, then deployment of the inflation to the second bladder would inflate the second bladder. The user could then rely upon the higher buoyancy capability of both bladders combined.

In the preferred embodiment the first bladder 15 is designed to provide 150N whilst when the second bladder is inflated, the life jacket provides 275N. In operation, the first bladder would inflate automatically giving 150N buoyancy. If the circumstances require, the second bladder inflates manually and then the life jacket would provide 275N across both bladders.

As shown in Figure 6, the first bladder 15 could be formed externally to the second bladder

25. However, in a preferred embodiment, the first bladder 15 is formed internally of the second bladder 25 at perimeter 29 leaving flange 31. Thus, the common wall could be internal of the two bladders or external of the two bladders; the latter as in the preferred embodiment.

Also in a preferred embodiment, an automatic gas cylinder 17 with manual release 23 is provided for the first bladder 15. The second bladder is provided with oral inflation tube 19.

Thus in the preferred embodiment, should the life jacket need to be relied upon the automatic inflation means 17 inflates the first bladder 15 to 150N. If required, the second bladder could be manually inflated using oral inflation tube 19 so that the life jacket provides at least 275N.

The present invention thus achieves the aim of providing a life jacket which is capable of meeting a broad variation of requirements and in particular the optimum required for the circumstances without increasing significantly the weight and size of the life jacket.

Claims

Claims:

1. An inflatable life jacket including a first bladder and a second bladder, each respective bladder having inflation means for inflating each bladder separately, wherein said first bladder comprises a single surface of material conjoined to the second bladder to share a common wall.

2. An inflatable life jacket as claimed in claim 1, in which said second bladder comprises two surfaces of material welded at the perimeter.

3. An inflatable life jacket as claimed in claim 1 or 2, in which said first bladder is smaller than the second bladder.

4. An inflatable life jacket as claimed in claim 3 in which said first bladder is welded to the second bladder along the perimeter of the single surface of material.

5. An inflatable life jacket as claimed in any one of the preceding claims in which an oral inflation tube is provided for each bladder.

6. An inflatable life jacket as claimed in any one of the preceding claims in which the inflation means for one or both bladders comprises a gas cylinder.

7. An inflatable life jacket as claimed in claim 6 in which said inflation means further includes a seal for automatic inflation.

8. An inflatable life jacket as claimed in either claim 6 or 7 in which said inflation means further includes a manual activation means for the gas cylinder.

9. An inflatable life jacket as claimed in any one of the preceding claims in which one bladder inflates prior to the other.

10. An inflatable life jacket as claimed in any one of the preceding claims, in which said first bladder enables the life jacket to provide a buoyancy of 150N and when both bladders are inflated enables the life jacket to provide a buoyancy of 275N.