Abstract:
A reserve parachute with air pockets at the apex of the canopy to allow rapid deployment of the reserve parachute without tangling with a malfunctioning main parachute. Skirt assist lines are provided to allow the lower edge of the canopy to spread on deployment and thus speed the opening of the canopy. In addition, ties may be provided between the pockets to maximize their effectiveness.

Description:
This application is a continuation of application Ser. No. 09/030,444, filed on Feb. 25, 1998, now U.S. Pat. No. 6,003,815, the entire contents of which are hereby incorporated by reference. 
    
    
     BACKGROUND TO THE INVENTION 
     1. Field of the Invention 
     The invention relates to parachutes and in particular to reserve parachutes. 
     2. Description of Related Art 
     Where a parachute is used to support a person, a reserve parachute is provided for use in the event that the main parachute does not deploy or does not deploy successfully. In general, where a reserve parachute is deployed, it is essential that the reserve parachute deploys very quickly. This is particularly true where the main parachute is being used for low level dropping. 
     There are a number of factors that mitigate against the rapid and successful opening of a reserve parachute in these circumstances. First, a pilot parachute cannot be used to promote rapid deployment of the reserve parachute as such pilot parachutes tend to fly up inside the malfunctioning main parachute causing a persisting entanglement between the reserve parachute and the main parachute. Secondly, the air flow regime in such circumstances may not be conducive to rapid deployment of the reserve parachute. 
     SUMMARY OF THE INVENTION 
     According to the invention, there is provided a reserve parachute comprising a conical canopy having an apex and a lower edge, the apex including a plurality of pockets which inflate on release of the canopy to deploy the canopy. 
     The use of pockets at the apex has been found to create a positive force to control the deployment while avoiding entanglements. 
     Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The following is a more detailed description of some embodiments of the invention, by way of example, reference being made to the accompanying drawing in which: 
     FIG. 1 is a diagrammatic view of a reserve parachute following deployment but before inflation and showing air pockets at an apex of a canopy of the parachute in an inflated condition, 
     FIG. 2 is a similar view to FIG. 1 but showing the use of skirt assist lines between rigging lines of the parachute and an interior of the canopy, and 
     FIG. 3 is a schematic view of a part of the canopy of the reserve parachute of FIGS. 1 and 2 showing an alternative arrangement of air pockets and the location point for break ties. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring first to FIG. 1, the reserve parachute comprises a canopy indicated diagrammatically at  10  connected by rigging lines, some of which are shown at  11 , to a harness  23  for attachment to a parachutist  24 . The canopy  10  may be of any suitable construction but both the canopy  10  and the rigging lines  11  are preferably made from lightweight materials; for example, the complete weight of the parachute may be less than 4 kg. 
     The canopy  10  has a lower edge  12  and an apex  13 . The apex is provided with four air pockets  14  which extend continuously around the apex over three gores with two plain gores in between. Of course, there may be more or less than four air pockets. 
     In use, the reserve parachute is carried with the main parachute (shown packed at  25 ) by the parachutist  24 . If the main parachute  25  malfunctions either by a failure to deploy or by incorrect deployment, the parachutist  24  activates the reserve parachute. As the reserve parachute enters the air stream, the air pockets  14  inflate rapidly to create a positive force that controls the deployment of the reserve parachute by lifting it out of the container and aligning it with the air flow. They act in a similar manner to a pilot chute. The fact that the air pockets  14  are on the canopy means that any tendency of the air pockets to entangle with the malfunctioning main parachute is avoided. 
     The rapidity of the deployment is also assisted by the fact that the canopy  10  and rigging lines  11  are of light weight. 
     Referring next to FIG. 2, parts common to FIG.  1  and FIG. 2 will be given the same reference numerals and will not be described in detail. 
     The reserve parachute of FIG. 2 is provided with skirt assist lines  15 . Each skirt assist line  15  is connected between a rigging line  11  and the canopy  10 . The connection is between a point  16  on the rigging line adjacent the lower edge  12  of the canopy and a point  17  on the interior of the canopy  10  spaced from the lower edge  12 . The length of each skirt assist line  15  is less than the distance between the points  16 , 17  along the associated rigging line  11  and along the canopy  10 . 
     The effect of this is that, when the canopy is deployed, the edge of the canopy  10  between the lower edge  12  and the point  17  of connection of the skirt assist lines  15  on the canopy  10  is relieved from tension. This allows this portion of the canopy  10  to move outwardly rapidly in the air flow to promote fast inflation of the canopy. This is particularly advantageous when deployment is at low level. 
     Referring next to FIG. 3, this shows an alternative arrangement of the canopy  10  of the reserve parachute from the air pockets  14 . As seen in this figure, the canopy is formed from a plurality of generally triangular gores  18 . The gores are connected at their apexes and stitched together along their side edges  19  leading to the apexes. Alternate pairs of gores  18  are covered by air pockets  14 . Each air pocket  14  is generally triangular with an apex connected at the apex of the canopy  10  and side edges  20  connected along the outer side edges  19  of the two gores  18  spanned by each air pocket  14 . 
     Two break ties  21  are provided between the adjacent side edges  20  of each pair of pockets  14 . One break tie  21  extends between two points adjacent the lower edges of the adjacent side edges  20  and one break tie  21  extends between two points on the side edges  20  towards the apexes of the air pockets  14 . 
     The purpose of these break ties  21  is to close the gores  18  between the pockets  14  during packing so that the air pockets  14  are substantially continuous around the apex of the canopy  10  when the reserve parachute is first deployed. This gives the air pockets  14  maximum effectiveness on deployment. As the canopy  10  inflates, the ties  21  break (as shown) to allow full deployment of the canopy. 
     It will be appreciated that the reserve parachutes described above with reference to the drawings provide a canopy which deploys accurately in the airstream without entangling with a malfunctioning main parachute and then opens quickly. This allows the reserve parachute to be used reliably at low altitudes. 
     The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.