GB2183554A - Automatically inflatable life jackets - Google Patents

Abstract

An automatic firing head cap 10 of an automatically inflatable lifejacket has the slotted outer end portion 16 thereof protected by a shield 24 which restricts access of water to a water-activatable cartridge contained therein. The shield 24 guards against accidental wetting of the cartridge without impairing activation on immersion. <IMAGE>

Description

SPECIFICATION Improvements relating to automatically inflatable life jackets This invention relates to automatically inflatable lifejackets and more particularly to the automatic firing capsules thereof which form part ofthe automatic inflation mechanism ofthejacketand initiate its inflation on immersion.

Such a mechanism conventionally comprises a valve body into which is screwed the nozzle of a cylinder charged with carbon dioxide, the nozzle being closed by a seal which is percable by one end of displaceablefiring pin slidably mounted in the body. Displacement ofthe pin is effected by the automaticfiring capsule which comprises a cap having an internallythreaded end which screws onto the valve body; a barrel housing a spring-loaded plun gerwhich engagestheotherendofthefiring pin; and an apertured end containing a water-activatable cartridge which, on immersion, expands two release the plunger, displacethefiring pin and causethe carbon dioxide to discharge through the valve into the life jacket.

Clearly, a balance has to be struck between preventing premature inflation when the life jacket is exposed to normal wetting in use occasioned by, for example, heavy rain, spray or a stray wave breaking aboard; and achieving rapid inflation when the wearerfalls overboard. With oldertypes of lifejacket, a balance was obtained as the jacket afforded protection againstaccidentalwetting ofthecapsule by water striking the wearer in a generally downwards or sideways direction. However, the new, halter-type life jackets do not afford as much protection against accidental wetting and activation of the capsule.

The balance, in thecase of both the olderand newer types of jacket, is improved by the present invention according to which there is provided a shield for an apertured cap of an automatic firing capsule of an inflatable life jacket, the shield restricting access ofwaterto the apertures in the cap and minimizing the risk of unwanted activation of awater-activatable cartridge contained therein.

Preferably, the shield prevents water gaining ac cess laterally to the cartridge and allows only limited end-on access.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings in which Figure lisa side elevation of a conventional automaticfiring capsule cap; Figure 2 is a plan ofthe cap of Figure 1; Figure 3 is a side elevation of the cap of Figure 1 fitted with a shield according to the invention; Figure 4 is a plan ofthecap and shield of Figure3; FigureS is a side elevation in which the left hand halfcorrespondsto Figure3andthe right hand half to Figure 1; and, Figure 6 is a plan similarly corresponding to Fig ures4 and 2.

Aconventionalautomaticfiring head cap 10as shown i the drawings is an integral, generallyfrusto- conical moulding formed from thermoplastics material and comprises an integrallythreaded,flanged, inner wend portion 12which is, in use, screwed onto a valve body which receives a CO2 cylinder and houses a firing pin for piercing the sealed nozzleofthecylin- der; a barrel 14 housing a plungerarrangedforaxial engagement with the firing pin and loaded by a surrounding spring (notshown); and an outer end portion 16 having a series of slots 18 extending along the side wall 20thereof and into the periphery ofthe end wall 22. On immersion, water gains access through the slots to a water-activatable firing cartridge (not shown) received in the cage-like end portion 16.

As shown in Figures 3 to 6, a shield 24 has a mouth portion 26 which fits over the barrel 14, a stepped portion 28 received over the end cage 16 and a reduced diameter end portion 30 projecting beyond the end wall 22 of the end cage 16.

The shield 24 allows water to reach the cartridge onlythrough the end portion 30 and those portions of the slots 18 in the end wall 22. The cartridge is thus protected from incidental wetting but is immediately fully wetted on immersion so that it expands tore- lease the plunger and displacethefiring pin, thus discharging the CO2 cylinder.

The effectiveness of the shield 24 is such that the cap 10 when thereto may be held for 15 minutes under a running tap withoutthe cartridge being ac- tivated, and yet when the cap is immersed in a cup of water, activation occurs immediately; it will be appreciated that activation is achieved with only minimal immersion, i.e without help from the additional pressure which would be generated in practice by immersion to a considerable depth.

1. Ashieldforfitting to an apertured cap of an automaticfiring capsule of an inflatable life jacket, the shield being arranged to restrict access of water to the apertures in the cap and to minimize the risk of unwanted activation of a water-activata ble cartridge contained therein.

2. Ashield as claimed in Claim 1 andarrangedto prevent water gaining access laterally to the cartridge and to allow only limited end-on access.

3. A shield as claimed in Claim 1 or2andcom- prising a mouth portion receivable over the barrel of the automatic firing capsule, an intermediate stepped portion receivable over the end cage of said capsule and a reduced diameter end portion.

4. Ashieldforfitting to an apertured cap of an automatic firing capsule, substantially as herein described with reference to the accompanying drawings.

5. An automatic firing capsule fitted with a shield as claimed in any preceding Claim.

6. An automatically inflatable life jacket incorporating a capsule as claimed in Claim 5.

7. Thefeatures herein described, or their equivalents, in any patentably novel selection.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (7)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improvements relating to automatically inflatable life jackets This invention relates to automatically inflatable lifejackets and more particularly to the automatic firing capsules thereof which form part ofthe automatic inflation mechanism ofthejacketand initiate its inflation on immersion. Such a mechanism conventionally comprises a valve body into which is screwed the nozzle of a cylinder charged with carbon dioxide, the nozzle being closed by a seal which is percable by one end of displaceablefiring pin slidably mounted in the body. Displacement ofthe pin is effected by the automaticfiring capsule which comprises a cap having an internallythreaded end which screws onto the valve body; a barrel housing a spring-loaded plun gerwhich engagestheotherendofthefiring pin; and an apertured end containing a water-activatable cartridge which, on immersion, expands two release the plunger, displacethefiring pin and causethe carbon dioxide to discharge through the valve into the life jacket. Clearly, a balance has to be struck between preventing premature inflation when the life jacket is exposed to normal wetting in use occasioned by, for example, heavy rain, spray or a stray wave breaking aboard; and achieving rapid inflation when the wearerfalls overboard. With oldertypes of lifejacket, a balance was obtained as the jacket afforded protection againstaccidentalwetting ofthecapsule by water striking the wearer in a generally downwards or sideways direction. However, the new, halter-type life jackets do not afford as much protection against accidental wetting and activation of the capsule. The balance, in thecase of both the olderand newer types of jacket, is improved by the present invention according to which there is provided a shield for an apertured cap of an automatic firing capsule of an inflatable life jacket, the shield restricting access ofwaterto the apertures in the cap and minimizing the risk of unwanted activation of awater-activatable cartridge contained therein. Preferably, the shield prevents water gaining ac cess laterally to the cartridge and allows only limited end-on access. An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings in which Figure lisa side elevation of a conventional automaticfiring capsule cap; Figure 2 is a plan ofthe cap of Figure 1; Figure 3 is a side elevation of the cap of Figure 1 fitted with a shield according to the invention; Figure 4 is a plan ofthecap and shield of Figure3; FigureS is a side elevation in which the left hand halfcorrespondsto Figure3andthe right hand half to Figure 1; and, Figure 6 is a plan similarly corresponding to Fig ures4 and 2. Aconventionalautomaticfiring head cap 10as shown i the drawings is an integral, generallyfrusto- conical moulding formed from thermoplastics material and comprises an integrallythreaded,flanged, inner wend portion 12which is, in use, screwed onto a valve body which receives a CO2 cylinder and houses a firing pin for piercing the sealed nozzleofthecylin- der; a barrel 14 housing a plungerarrangedforaxial engagement with the firing pin and loaded by a surrounding spring (notshown); and an outer end portion 16 having a series of slots 18 extending along the side wall 20thereof and into the periphery ofthe end wall 22. On immersion, water gains access through the slots to a water-activatable firing cartridge (not shown) received in the cage-like end portion 16. As shown in Figures 3 to 6, a shield 24 has a mouth portion 26 which fits over the barrel 14, a stepped portion 28 received over the end cage 16 and a reduced diameter end portion 30 projecting beyond the end wall 22 of the end cage 16. The shield 24 allows water to reach the cartridge onlythrough the end portion 30 and those portions of the slots 18 in the end wall 22. The cartridge is thus protected from incidental wetting but is immediately fully wetted on immersion so that it expands tore- lease the plunger and displacethefiring pin, thus discharging the CO2 cylinder. The effectiveness of the shield 24 is such that the cap 10 when thereto may be held for 15 minutes under a running tap withoutthe cartridge being ac- tivated, and yet when the cap is immersed in a cup of water, activation occurs immediately; it will be appreciated that activation is achieved with only minimal immersion, i.e without help from the additional pressure which would be generated in practice by immersion to a considerable depth. CLAIMS

1. Ashieldforfitting to an apertured cap of an automaticfiring capsule of an inflatable life jacket, the shield being arranged to restrict access of water to the apertures in the cap and to minimize the risk of unwanted activation of a water-activata ble cartridge contained therein.

2. Ashield as claimed in Claim 1 andarrangedto prevent water gaining access laterally to the cartridge and to allow only limited end-on access.

3. A shield as claimed in Claim 1 or2andcom- prising a mouth portion receivable over the barrel of the automatic firing capsule, an intermediate stepped portion receivable over the end cage of said capsule and a reduced diameter end portion.

4. Ashieldforfitting to an apertured cap of an automatic firing capsule, substantially as herein described with reference to the accompanying drawings.

5. An automatic firing capsule fitted with a shield as claimed in any preceding Claim.

6. An automatically inflatable life jacket incorporating a capsule as claimed in Claim 5.

7. Thefeatures herein described, or their equivalents, in any patentably novel selection.