GB2325651A

GB2325651A - Launching apparatus and projectile

Info

Publication number: GB2325651A
Application number: GB9710892A
Authority: GB
Inventors: Michael Henry Schindler; Roderick Paul Mcdonald Gillies
Original assignee: MARINE LIFELINE
Current assignee: MARINE LIFELINE
Priority date: 1997-05-27
Filing date: 1997-05-27
Publication date: 1998-12-02
Also published as: AU7543598A; GB9710892D0; WO1998054539A1

Abstract

A projectile comprising a compressed gas cylinder (1) and a nose cone (2) are particularly suited to marine safety applications. Prior to deployment the projectile is mounted within a launcher (3, 4, 7, 8). When a trigger (4) is operated a valve (6) on the projectile is opened and compressed gas escapes from the cylinder (1) to propel the projectile out of the launcher. A range of 200 metre or more is easily obtained. The nose cone (2) of the projectile may be buoyant or may contain a buoyancy aid or raft which inflates on contact with water. Additionally or alternatively the projectile is provided with a tether (5). Unlike conventional explosive launchers, such apparatus may be operated by unskilled personnel and in hazardous environments such as oil rigs and avalanche zones.

Description

LAUNCHING APPARATUS AND PROJECTILE The present invention relates to a launching apparatus and projectile having particular, but not exclusive, application to marine life-saving applications.

Life-saving devices are known such as buoyancy rings provided on ships, piers and so on. Should somebody fall into the water the ring is thrown to them to help maintain their buoyancy until a full rescue can be effected. However, such buoyancy rings have a very limited range which is dependent upon the strength.of the person throwing it.

Mechanical line throwing devices are also known which provide a somewhat greater range. However, these devices are propelled by means of an explosive launcher which has several disadvantages. In particular, such a launcher cannot be used in locations where flammable materials or gases are present. The rapid expansion of air pressure caused by detonation of the explosive can cause avalanches or rock falls, and explosive propellant imposes particular storage requirements upon the device.

It is an object of the present invention to provide a launcher and projectile which ameliorates the above disadvantages.

According to a first aspect of the present invention, there is provided a launching apparatus and projectile which launching apparatus comprises a barrel within which the projectile fits, wherein the projectile comprises a source of pressurized gas which gas is released to propel the projectile.

For marine safety applications, the projectile may be arranged to be buoyant in its own right or to contain a buoyancy aid which is inflated after the projectile has landed in the water.

The projectile may be. attached to a tether which may also be attached to the launcher or a buoy, for example.

The present invention has particular application to use in oil and gas fields, for example on an oil rig, in which explosive launchers cannot be used. Because the launching apparatus is quieter than an explosive launcher, it may also be used in areas of avalanche danger.

The invention may provide a life-saving apparatus which is particularly suitable for operation by unskilled personnel in a passenger ship, for example, even if moving at a modest speed of 10 to 15 knots, a passenger who falls overboard will very soon find himself beyond the range of a hand-thrown buoyancy aid. By providing a life-saving device comprising a launcher and projectile in accordance with the present invention, unskilled personnel will be able to quickly launch a tethered buoyancy aid to such a person. Since the range may easily be 100 metres or more, a buoyancy aid can still be provided to a person who has fallen overboard, despite the movement of the ship.

The projectile of the present invention may be provided with a buoyancy aid which inflates on contact with water. Such a device may respond to hydrostatic pressure (for example, once the projectile descends a short distance below the surface of the water).

The launching apparatus may be hand-held, provided with a stand such as a tripod or provided with means for mounting to the rail or superstructure of a vessel or oil rig.

The projectile may be tethered to the launcher, the vessel or structure upon which it is mounted or arranged or to a buoy, such as a danbuoy. The projectile, inflatable buoyancy aid and/or the buoy may each be provided with a light such as a flashing light or strobe and a navigation beacon or any combination in order to facilitate recovery of the people using the life-saving apparatus.

Alternatively, the projectile may have no tether and this may be particularly suitable for launching life-rafts from a large passenger ship.

According to a second aspect of the present invention, there is provided a launching apparatus and projectile, which projectile is attached to a tether and which launching apparatus comprises a barrel within which the projectile fits, wherein one of the launching apparatus and the projectile comprises a source of pressurized gas which gas is released to propel the projectile.

The tethered projectile may alternatively be launched by a source of pressurized gas located at the launcher. This may conveniently result in a lighter projectile.

Further preferred features of the present invention are set out in the accompanying dependent claims.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a perspective view of a launcher and projectile in accordance with an embodiment of the invention; Figure 2 shows the unit of Figure 1 momentarily after the projectile has been launched; Figure 3 shows the valve and coupling assembly of a compressed gas cylinder used to propel the projectile; Figure 4 shows an inflatable life-saving device which has deployed from the projectile; Figure 5 shows an end-view of the barrel of a launcher according to an embodiment of the invention; Figure 6 shows the arrangement of a nose-cone fitted to a projectile in accordance with an embodiment of the. invention; Figure 7 shows a possible attachment between a tether and the projectile; and Figure 8 shows a schematic diagram of a valve-release mechanism which may be used in the present invention.

Figure 1 shows a side view of a tripod-mounted embodiment of the invention. In this figure the projectile, of which only a nose-cone 2 is visible, is mounted within a launching tube or barrel 3. The barrel is mounted on a tripod 7 and a tether 5 is shown connected to the projectile. A trigger mechanism is also provided which will be discussed in greater detail below.

Figure 2 shows another side view of the arrangement shown in Figure 1, just after the projectile has been launched. The projectile comprises a pressurized gas cylinder 1, a nose-cone 2 and a high pressure valve arrangement 6. The projectile is attached to a tether 5, which may conveniently comprise floating polypropylene line for marine applications. The launching arrangement comprises a barrel 3 mounted on the tripod or stand 7 together with trigger 4 and a safety tag 8. The safety tag 8 is shown in position for convenience but would, in fact, have been removed prior to launching of the projectile.

The unit operates broadly as follows. A pressurized gas cylinder 1 which forms part of the projectile is charged and maintained with gas such as air at a high pressure. The pressure of the gas and the capacity of the container 1 are dependent upon the application and will be discussed in more detail below. The container 1 is provided with a valve arrangement 6 which allows the escape of the pressurized gas when released. When the projectile is to be launched, the safety tag 8 is removed and the trigger mechanism 4 operated. This has the effect of opening the valve 6 and permitting the escape of the pressurized gas in the cylinder 1. In the launching apparatus shown in Figure 2, the projectile is launched by a combination of Newton's Second Law (a reaction to the escape of gas) and the pressure build-up within the launching tube 3. The invention has also been found to work with an open launching tube in which case the projectile is propelled by reaction to the escape of the compressed gas. This is of particular importance to a hand-held launching apparatus because of the absence of a recoil force applied to the user.

For life-saving applications the container 1 may conveniently be of between 700 ml and 2,000 ml in capacity. The pressure to which the gas should be pressurized is dependent upon the desired range of the apparatus Values of between 2,000 and 3,000 Ibs per square inch may be provided. As is known, where pressures exceed approximately 250 Ibs per square inch mechanical valves cannot be relied upon. The valve mechanism 6 is arranged to be a hydraulic ball valve. A range of 200 metres is readily obtainable using compressed cylinders of this size containing air compressed to no more than 3,000 psi.

The trigger mechanism will be discussed in greater detail with reference to Figure 8 below.

Figure 3 shows a portion of the cylinder 1 coupled to a valve unit 12 and an O-ring seal 13 is provided to ensure a gas-tight seal. A quick release coupling 14 is provided to allow the pressurized gas to be placed in the cylinder. A further O-ring seal 15 is provided to ensure a gas-tight fitting with a source of compressed gas. The valve 12 comprises a hydraulic ball valve of any suitable type.

The pressurized gas may be re-charged by various methods, for example: 1. From an air-line ring main which could be fitted to larger vessels.

2. From a compressor.

3. By coupling to a larger compressed air cylinder to provide cylinder-to-cylinder recharging.

Figure 4 shows an embodiment of the invention in a marine life-saving application. A nose-cone 24 of.the projectile deforms or splits open or detaches to allow deployment of an inflatable horseshoe 21. The deployment of the horseshoe may conveniently be arranged to occur on contact with water. To this end, a water-sensitive valve 22 is provided. In one embodiment the valve is responsive to hydrostatic pressure such that when the projectile sinks below the water to a depth of 6 cm the horseshoe will inflate.

The nose-cone conveniently comprises a moulded arrangement as shown in Figure 6.

The nose-cone is moulded in one piece together with weaknesses along a pair of helical lines. The nose-cone may deform or split apart on collision with water or may do so in response to the deployment of the inflatable horseshoe 21. To ensure that the watersensitive valve 22 actuates properly, the nose-cone may be provided with a series of holes to ensure ingress of water once the projectile is beneath the water level.

As shown in Figure 4, a small compressed gas cylinder 23 is provided to inflate the horseshoe 21. Such a cylinder may contain carbon dioxide, air or other suitable compressed gas.

As an alternative to the arrangement shown in Figure 4, the present invention may be used to deploy a larger inflatable device, for example an inflatable raft (not shown).

The principle of operation is exactly the same, the size of the cylinder 1 (Figure 2) and the pressure of the gas stored therein may be adjusted as appropriate to carry the larger payload. The raft may be inflated in a manner analogous to that described for the inflatable horseshoe.

For deployment of a raft, it may be inappropriate to tether the raft to the ship (for example the ship may be sinking). As an alternative, the raft may be untethered or tethered to a buoy such as a danbuoy (not shown).

The projectile, inflatable horseshoe or life ring may be provided with an electronic navigation beacon to facilitate recovery of the people using the life-saving equipment.

A lamp, for example a flashing lamp or strobe, may alternatively or additionally be provided for the. same. purpose.

Figure 5 shows an end view of the barrel and a sectional view of the projectile shown in Figure 1. The inside of the barrel 3 is provided with four strips of a material having low frictional properties. Such materials are readily available from several manufacturers.

When the projectile is connected to a tether (see Figure 7) it will not usually be possible for the projectile to be a snug fit within the barrel 3 as would a bullet in a gun. This has not been found to cause any problems, indeed the barrel of the launching device can comprise an open tube. However, a closed tube will generally ensure more effective use of the escaping compressed gas in launching the projectile. A closed tube also confines the escaping gas and protects people in the vicinity of the apparatus. The launching tube 3 shown in Figure 5 also comprises a membrane 42 arranged across the gap between the tube 3 and the projectile. While the projectile is exiting the tube, the expelled gas will be retained, at least partially, by the membrane 42 to provide an extra expelling force to the projectile.

Figure 7 shows one means by which the tether may be connected to the projectile. A metal tag 50 is bolted between the gas container 1 and the valve 6. One end of the tag 50 is provided with an eye 52 to which a sprung fastener (or other suitable means of fastening the tether) may be attached.

Figure 8 shows a schematic diagram of an embodiment of the trigger mechanism. The valve 6 is operated by a two-sided lever 8 which is opened in a clockwise direction. A compression spring 9 is provided in a compressed state to urge the lever 8 into the open position. However, the spring is retained in the compressed position by a trigger 10.

Actuation of the trigger 10 releases the compression spring 9 which causes the lever 8 to move very quickly. A fast and effective flow of gas from the container 1 then launches the projectile. The flow of gas will normally occur for approximately one to two seconds.

Direct actuation of the lever 8 by the user of the apparatus has not been found to be so satisfactory because the valve 6 tends not to open so quickly.

In either case, a projection 11 is preferably.provided on the barrel 3 of the launching apparatus which is placed so as to move the lever 8 into the fully-opened position as the projectile leaves the barrel 3.

It is possible to re-use a life-saving apparatus embodying the principles of the present invention. The nose-cone (Figure 6) may be re-usable or replaceable. The cost of providing a new nose-cone in a.moulded plastics material is very low. Inflatable buoyancy aids such as the ring 21 (Figure 4) may be deflated and re-packed together with a recharged cylinder 23. The main cylinder 1 of the projectile can be recharged as discussed above.

After deployment of a marine life-saving device in salt water the whole apparatus should be thoroughly cleansed or purged to ensure that the corrosive sea-salts are removed.

The cylinder 1 will generally be made of cast aluminium in order to withstand the high gas pressures required. The launching tube 3 may comprise steel, preferably stainless steel or a plastics material particularly for an open-ended realisation. The inflatable devices and water sensitive valves are readily obtainable components from marine safety suppliers.

The length of the tether is dependent on the application and will typically be between 60 and 80 metres. Projectiles launched in accordance with the invention have been found to stay on course for this distance. A range of greater than 200 metres is possible, however.

The present invention has been described by way of example but the skilled person will readily contemplate a number of implementations and modifications of the present invention. The scope of protection is determined only by the appended claims.

Claims

CLAIMS:

1 A launching apparatus and projectile which launching apparatus comprises a barrel within which the projectile fits, wherein the projectile comprises a source of pressurized gas which gas is released to propel the projectile.

2. A launching apparatus and projectile as claimed in Claim 1, wherein the projectile is attached to a tether.

3. A launching apparatus and projectile as claimed in Claim 2, wherein the tether i! further attached to the launching apparatus.

4. A launching apparatus and projectile as claimed in Claim 2, wherein the tether is further attached to a buoy.

5. A launching apparatus and projectile as claimed in any one of Claims 1 to 4, wherein the launching apparatus comprises means for mounting to a ship.

6. A launching apparatus and projectile as claimed in any one of Claims 1 to 4, wherein the launching apparatus further comprises a stand.

7. A launching apparatus and projectile as claimed in any one of Claims 1 to 4, further comprising handle means to permit hand-held operation of the launching apparatus.

8. A launching apparatus and projectile as claimed in any one of Claims 1 to 7, wherein the projectile is buoyant.

9. A launching apparatus and projectile as claimed in any one of Claims 1 to 7, wherein the projectile comprises an inflatable buoyancy aid for a person and means for inflating the buoyancy aid.

10. A launching apparatus and projectile as claimed in any one of Claims 1 to 7, wherein the projectile comprises an inflatable raft and means for inflating the raft.

11. A launching apparatus and projectile as claimed in Claim 9 or Claim 10, wherein the means for inflating is responsive to contact with water.

12. A launching apparatus and projectile as claimed in Claim 11, wherein the means for inflating is responsive to hydrostatic pressure.

13. A launching apparatus and projectile as claimed in any one of Claims 1 to 12, wherein means for releasing the pressurized gas comprise a valve, a spring for urging the valve into an open position and trigger means for holding the valve closed until the trigger means are actuated.

14. A launching apparatus and projectile as claimed in any one of Claims 1 to 13, wherein the inside of the barrel comprises a material selected for a low friction property.

15. A launching apparatus and projectile as claimed in any one of Claims 1 to 14, wherein the projectile comprises a nose-cone.

16. A launching apparatus and projectile as claimed in Claim 15., wherein the nosecone is arranged to detach from the projectile upon landing of the projectile.

17. A launching apparatus and projectile as claimed in any one of Claims 1 to 16, wherein the projectile includes a radio navigation beacon.

18. A launching apparatus and projectile as claimed in any one of Claims 1 to 17, wherein the projectile includes a lamp or a strobe.

19. A launching apparatus and projectile which projectile is attached to a tether and which launching apparatus comprises a barrel within which the projectile fits, wherein one of the launching apparatus and the projectile comprises a source of pressurized gas which gas is released to propel the projectile.

20. A launching apparatus and projectile substantially as herein described with reference to the accompanying drawings.