BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a conventional parachute having a payload attached to the parachute in an early stage of deployment;
FIG. 2 illustrates the parachute of FIG. 1 fully deployed with the reefing line severed from the parachute;
FIG. 3 illustrates a partial view of the skirt of a parachute which utilizes steel rings to secure the reefing line to the parachute;
FIG. 4 illustrates a partial view of the skirt of the parachute of FIG. 1 and one of the flexible fabric loop assemblies which secure the reefing line to the parachute;
FIGS. 5 and 5A illustrate detailed views of the flexible fabric loop assembly for one of the reefing loops of the parachute; and
FIGS. 6 an 6A illustrate detailed views of the structure for attaching a parachute suspension line to the skirt of the parachute canopy.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
Referring to FIG. 1, there is shown a conventional parachute 10 having a payload 12 attached to the parachute 10 in an early stage of the parachute's deployment.
Parachute 10 comprises a generally circular canopy 14 which has an upper or apex area 18 and a skirt area 20. The circular canopy 14 of parachute 10 has a plurality of equally spaced apart radial seams 22 and a plurality of equally sized gores 24. The radial seams 22 are utilized to secure adjacent gores 24 of the canopy 14 together. The circular canopy 14 of parachute 10 may be fabricated from well known, commercially available parachute material such as nylon.
Parachute 10 also includes a plurality of equally spaced apart suspension lines 26 each of which is attached at one end to the skirt 20 of canopy 14 and at the opposite end of a riser 29. The other end of the riser 29 attaches to payload 12.
Parachute 10 also has a reefing line 30 positioned around the skirt of parachute 10. Reefing line 30 is a short length of line routed through steel reefing rings 32 (FIG. 3) attached at the skirt 20 of the parachute 10, is utilized to limit the initial drag area of the parachute. The reefing line 30 also allows the canopy 14 of parachute 10 to be packed and to open in a controlled manner.
Referring to FIGS. 1 and 2, this short length of line 30 forms a circle at the skirt 20 of the parachute 10. Pyrotechnic line cutters 36 are generally used to sever the reefing line 30 at a specific time, allowing the parachute 10 to fully inflate once the payload 12 has slowed down. FIG. 2 illustrates the canopy 14 of parachute 10 fully inflated with the reefing line 20 severed from parachute 10. At this point in time parachute 10 has opened and is falling steadily. A state of equilibrium exist in which the resultant force of drag and lift acting upon the falling parachute is equal to the weight of the parachute 10 and the payload 12.
Referring to FIGS. 1, 2 and 3, large steel reefing rings 32 attached to the skirt 20 of parachute 10 are used to secure the reefing line 30 to parachute 10. The steel reefing rings 32 are equally spaced apart about the skirt 20 of parachute 10. When the parachute 10 begins to inflate, the skirt 20 of parachute 10 can only expand to the circle formed by the reefing line 30 in the manner illustrated in FIG. 1. After a length of time in which the velocity of the payload 12 has sufficiently slowed down, pyrotechnic line cutters 36 fire which sever the reefing line 30. Without the restraining force of the reefing line 30, the parachute skirt 20 is allowed to fully inflate as depicted in FIG. 2.
Unfortunately, while parachute fabrics generally compress easily, the steel reefing rings 32 do not, and a significant amount of effort must by made to prevent the rings from damaging the parachute fabric, the reefing line 30, the line cutters 36, or other rings. Since the damage occurs more frequently as the force required to pack parachute 10 is increased, the steel rings 32 severely limit the density to which a parachute 10 can be packed.
Referring now to FIGS. 1, 4, 5 and 5A, an alternative to using steel rings 32 (FIG. 3) to secure the reefing line 30 to the skirt 20 of parachute 10 is a reefing loop assembly 40 which is shown in FIGS. 5 and 5A. The reefing loop assembly 40 includes a flexible fabric material 42 which has a tubular shape and is fabricated from a low friction material such as Teflon. Inserted within the flexible fabric material 42 is a Kevlar strip 44, such as Kevlar, which strengthens the reefing loop assembly 40.
Each suspension line 26 includes a suspension line loop 38 at the end of the suspension line 26 attached to the skirt 20 of parachute 10 (FIG. 4). The suspension line loop 38 allows a user to attach the suspension line 26 to the skirt 20 of parachute 10 by looping the suspension line 26 through the loop 38 of suspension line 26.
Referring to FIGS. 1 and 4, each reefing loop assembly 40 is sewn onto the parachute skirt 20 at a radial tape 46. Each radial tape 46 is aligned with one of the radial seams 22 on the canopy 14 of parachute 10. The reefing line 30 passes through an opening 50 formed between the reefing loop assembly 40 and a radial attachment loop 52 at each radial seam 22 of the canopy 14 of parachute 10. The reefing line is also routed through reefing line cutters 36 at two opposing radial seams 22 of the canopy 14 of parachute 10. The reefing line 30 is fingertrapped to itself to form a complete circle which remains intact until the reefing line cutters 36 severe the reefing line 30 from the parachute 10.
Referring to FIGS. 1, 6 and 6A, FIG. 6A illustrates a side view of the reefing loop assembly 40 and parachute structure which is utilized to secure the reefing line 30 and suspension line loop 38 for each of the suspension lines 26 to the skirt 20 of the parachute 10. As shown in FIG. 6A, the reefing loop assembly 40 forms the outer most portion of the parachute structure used to support the suspension lines 26 and reefing line 30. The reefing loop assembly 40 is attached to the radial tape 46 by sewing the reefing loop assembly 40 onto the radial tape 46. Located inside the radial tape 46 is a layer of fabric 36, such as kevlar, which is a buffer between the radial tape 46 and the parachute cloth 58.
From the foregoing, it may readily be seen the present invention comprises a new, unique and exceedingly useful flexible reefing loop assembly for use in securing a reefing line to a parachute, which constitutes a considerable improvement over the known prior art. Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically describer.
Patent Application
20070267547
