The present invention relates to parachutes and in particular to a parachute assembly having means for extracting a parachute canopy for deployment. More particularly, but not exclusively, the invention may be used in the extraction of a reserve parachute which may need to be deployed if a main parachute fails to deploy or malfunctions.

Typically a military parachutist is provided with a main parachute arranged in a back-mounted pack and normally opened by a static line, and a fron -mounted reserve parachute which is opened manually by the parachutist should the main parachute fail to deploy or malfunction. For example, the main parachute may "squid", that is its canopy may adopt an elongate shape and not deploy fully, or its rigging lines may become twisted, again preventing a satisfactory deployment of the canopy. In such circumstances, particularly at low levels, it is essential to deploy a reserve parachute quickly and in such a manner that the reserve does not itself become entangled in the main canopy, which cannot be cut away in the short time available. Several systems are known for extracting and deploying reserve parachutes. In a first system, the reserve canopy is pushed out of its pack by a spring member. However, this is not particularly satisfactory since the mass of the canopy is such that it is not pushed a great distance away from the parachutist, which means that as it deploys, the canopy may become entangled with the main canopy, or with the parachutist or his equipment.

A second proposal, described in GB-A-1523807 , is to use an auxiliary, or drogue, parachute to extract the primary reserve parachute from the pack. The auxiliary parachute is ejected out of the pack by an ejection

spring mounted in the bridle which extends between the auxiliary parachute and the primary parachute, adjacent the apex of the auxiliary shroud lines. After ejection, the auxiliary parachute opens to extract the primary parachute from the pack. In a further system, as described in FR-A-2502580, an ejection spring is actually mounted within the auxiliary parachute canopy. A problem with such systems, however, is that since the spring remains closely attached to the auxiliary parachute as it is ejected, it adds to the mass of the parachute, which means that the auxiliary canopy may tend to fall downwardly relative to the pack before it moves upwardly to deploy. This means that the deployment time is increased, and that the auxiliary parachute after deployment may become entangled with a mis-deployed main parachute. This is especially important in situations where the main canopy partially malfunctions to the extent that the rate of descent is sufficiently high to cause injury to the paraichutist but not high enough to facilitate effective deployment of the reserve parachute.

The present invention seeks to overcome these problems and from a first aspect, the invention provides a parachute assembly comprising a primary parachute and an auxiliary parachute coupled to said primary parachute for extracting said primary parachute from the parachute pack, and ejection means for ejecting the auxiliary parachute from the pack, said ejection means being arranged so as effectively to be decoupled from the auxiliary parachute during ejection of the auxiliary parachute.

Thus in accordance with the invention, the ejection means s arranged such that effectively ts nass will not add to that of the ejected auxiliary parachute, thereby reducing the tendency of the auxiliary parachute to sink before deployment and thereby reducing the deployment time. Furthermore, the full drag force

exerted by the auxiliary parachute can then act to deploy the primary parachute rather than having to lift additionally the mass of the ejection means.

In one embodiment, the ejection means may be arranged remotely from the auxiliary parachute, for example in an extraction line or bridle connecting the auxiliary parachute to the primary parachute at a location remote from the auxiliary parachute, most preferably adjacent the apex of the primary parachute. Being remote from the auxiliary parachute, the mass of the ejection means will not tend to cause the auxiliary parachute to sink.

Preferably, however, the ejection means is separate from the auxiliary parachute, that is it is not coupled to it. In this way the ejection means may fall away from the auxiliary parachute after its operation and not interfere with ejection or deployment of the auxiliary canopy.

From a second broad aspect therefore, the invention provides a parachute assembly comprising a primary parachute and an auxiliary parachute coupled to said primary parachute for extracting said primary parachute from the parachute pack, and ejection means for ejecting the auxiliary parachute from the pack, said ejection means being arranged so as to fall away from said auxiliary parachute during deployment.

Preferably the ejection means comprises resilient means which may be pre-loaded to provide an ejection force. In the preferred embodiment, the ejection means comprises a compression spring which is pre-loaded to provide an ejection force. The spring is preferably arranged to have a large extension relative to its coiled length so that it applies a sustained accelerating force to the auxiliary parachute over a relatively long distance and time, thereby maximising the momentum of the auxiliary parachute at the point when the spring falls away. Most preferably the spring

is provided within a sleeve of fabric or the like to reduce the risk of entanglement with other parts of the system. Preferably the sleeve is vented to prevent any damping effect on the spring during its ejection. Preferably means are provided associated with the spring means which will allow the spring means to be retained in a pre-loaded condition during packing of the parachute assembly, said means being released once the assembly is packed to 'cock' the spring means. In the sleeve arrangement described above, for example, the sleeve may have ties which will allow the spring to be compressed and retained in a compressed condition until the pack is closed, or partially closed, at which point the ties may be released, to leave the spring in a pre- loaded condition. Of course other pre-loading devices may be envisaged which achieve this, for example a catch or the like. It would also be possible to have pre¬ loading means which would be released upon the pack opening. Prior to ejection, the ejection means is preferably located in the parachute pack between the primary- parachute and the auxiliary parachute so that the ejection means can propel the auxiliary parachute clear of the parachutist, and a mis-deployed main parachute, before the primary parachute is deployed.

Preferably the primary parachute is arranged in a compartment which is closed by two or more flaps. This prevents, or reduces, the chances of the ejection means becoming entangled in the primary parachute. Staging means may be provided to keep this compartment closed until the auxiliary parachute has been fully deployed. Particularly preferred staging means comprise a bight formed in an end region of the bridle closest to the primary parachute or a pin attached to the bridle, the bight or pin securing the flaps enclosing the primary parachute by passing through a loop which is itself attached to the lower flap and which passes through a

hole in the upper flap (a "staple and hasp"-type closure) , so that when the bridle becomes taut the bight or pin is pulled out of the loop by the bridle, so releasing the flaps to allow the primary parachute to be extracted.

To facilitate deployment of the auxiliary parachute, an orienting mass may be arranged to orient the auxiliary parachute in the correct direction. This mass need not be very large, typically for example about 0.05-0.15 kg. The mass of the orienting mass is intended to be significantly less than that of the ejection means, so as not to negate the lifting force of the auxiliary parachute. Preferably the mass is arranged at, or closely adjacent, the base of the auxiliary parachute, for example at the top of the bridle or around the attachment loop securing the bridle to the auxiliary parachute. The mass may comprise lead shot or the like in a sleeve which may be attached to the bridle etc., or a fishing weight or the like secured to the bridle etc. Heat shrink sleeving may be attached around the mass to secure it in position and to prevent entanglement.

In an alternative arrangement the mass may comprise a metal link arranged between a loop at the upper end of the bridle and another loop at the base of the auxiliary parachute.

The orienting mass is preferably arranged between the auxiliary parachute and the ejection means in the assembled pack. A preferred embodiment of the invention will now be described by way of example only and with reference to the accompanying drawings, in which:

Fig. l shows a schematic section though a reserve parachute pack in accordance with the invention,- Fig. 2 shows an exploded view of the pack of Fig.

1;

Fig. 3 shows, schematically, an initial stage in

the opening of the pack of Fig. 1,•

Figs. 4 to 6 show, schematically, later stages in the deployment of the primary reserve parachute of the pack; Fig. 7 shows a first form of auxiliary mass for use in the pack of Figs . 1 to 6 ,• and

Fig. 8 shows a second form of auxiliary mass for use in the pack of Figs . 1 to 6.

With reference to Figs. 1 and 2, a reserve parachute pack 2 which is strapped to a parachutist's chest by a harness (not shown) comprises an outer pack 4 and an inner pack 6. The inner pack 6 contains the folded main reserve parachute 8 with its rigging lines 10 which are retained, in a known manner, in a pocket 12. The inner pack 6 is closed by a pair of flaps 14,16. The outer pack 4 houses an auxiliary parachute 18 which is attached to the crown region 20 of the primary parachute canopy by a bridle 22. The auxiliary parachute typically has a deployed diameter of about 1.5m, and is very light, of the order of only 350g. Typically the bridle 20 may be about 3-4m in length between its attachment to the auxiliary parachute 18 and the crown of the primary parachute. Such a length prevents so-called "horse-shoe" malfunctions and allows the auxiliary to be projected well clear of a malfunctioning main parachute. The bridle 22 is stowed in a pocket 24 provided on one of the inner flaps 14.

Arranged between the auxiliary parachute 18 and the flaps 14,16 of the inner pack 2 is a compressed ejection spring 26 which is contained within a fabric sock or sleeve 28. This sleeve prevents the spring 26 from becoming entangled with the bridle 22 which, as can be seen extends along one side of the sleeve 28. Typically the spring may have a diameter of about 150 mm, a compressed length of about 10-25 mm and a relaxed length of between 750-800 mm, a mass of about 300g, and provide an ejection force of 100 to 150N.

An orienting mass 30 of about 50-150g is arranged at the base of the shroud lines 32 of the auxiliary parachute adjacent the upper end of the bridle 22, and is intended to orient the auxiliary parachute in the correct attitude for opening, without substantially adding to the weight of the parachute . The orienting mass 30 also provides inertia to the auxiliary parachute 18 after it has been ejected thereby maximising the separation of the auxiliary from the pack 2 after the spring 26 has dropped away. As shown in Figs. 7 and 8, the mass may, for example, be in the form of lead shot or the like, provided in a tubular sleeve 34 stitched to the auxiliary attachment loop 36 or in the form of a fishing weight 38 attached to the upper part of the bridle 22 and held in position by a sleeve 40 of heat shrinkable material.

Assembly of the pack 2 and its method of operation will now be described. Firstly, the rigging lines 10 are folded in a known manner as shown in Fig. 2 and placed in the retaining pocket 12, and the primary parachute 8 then folded and positioned on top of the rigging lines 10 as shown. The inner flaps 14,16 are then folded over to close the inner pack 4, and the bridle 22 is then folded and inserted in the stowage pocket 24. The sleeved ejection spring 26 is then positioned on top of the pocket 24. The spring 26 may already have been compressed to its loaded condition, or may be compressed in situ. In one arrangement, a tie (not shown) with a slip knot may be tightened around the spring sleeve 28 and an end of the tie positioned so that the knot may be released and the tie removed after the pack is closed. The outer pack 4 is closed with four flaps 42 arranged in a cruciform manner, and two opposed flaps may be secured together while the other two are unsecured to allow access to the tie, and secured after the tie is removed. Alternatively some other releasable arrangement, such as a pin or catch may

be employed.

The orienting mass 30 and folded auxiliary parachute 18 are then placed on top of the spring 26, and the outer flaps 42 closed and secured after, if appropriate, releasing the spring 26.

In use, should a primary parachute fail to deploy or malfunction, the parachutist opens the outer flaps 42 using a rip cord, or the like in the usual manner. Once the flaps 42 are released, the auxiliary parachute 18, the orienting mass 30 and the bridle 22 are ejected out of the pack under the force of the ejection spring 26, as shown schematically in Fig. 3.

By virtue of reaction against the inner pack 6, the spring 26 is also ejected, as shown. However, unlike the prior art systems, since the spring 26 is not attached to the auxiliary parachute 18, it will not be entrained by it during ejection, and will fall away, as shown in Fig. 4, which means that the auxiliary parachute 18 is less likely to be dragged downwardly by the mass of the spring before moving upwardly to open, and that the drag force of the auxiliary parachute will not have to entrain the mass of the spring. The orienting mass 30 assists in the rapid orientation of the parachute for opening without causing significant sinking of the auxiliary parachute 18 prior to opening. As the bridle 22 is pulled away from the pack by auxiliary parachute 18 as it opens, it will open the inner pack 6 and will extract the primary reserve parachute 8 from the inner pack 6 as shown in Figs. 4 and 5. The primary reserve parachute 8, having been projected well clear of the malfunctioned primary parachute 50 will then be able to deploy fully as shown schematically in Fig. 6.

It will be apparent that many variations to the above described embodiment can be made without departing from the scope of the invention. For example, whilst a simple compression spring 26 has been shown as the

ejection means, other, more complicated devices could also be used.

The present invention has been found to provide rapid canopy deployment and also to permit the ejection of the auxiliary parachute a considerable distance compared to prior art arrangements, so that the likelihood of entanglement with mis-deployed primary parachutes is reduced.