1. Field of the Invention
The invention described and shown herein relates to parachutes and is directed more particularly to a low cost cargo parachute for use in providing water, food and supplies to areas unreachable by other means, for humanitarian relief, or for remote military operations.
2. Description of the Prior Art
In use, very few airdrop parachutes are returned for reuse. By and large, only in training does reuse of parachutes occur. Yet, parachutes are relatively expensive items.
Most cargo parachutes are round with numerous suspension lines attached to a skirt portion of the parachute fabric. A multitude of lines are sewn into the fabric to reinforce the fabric which itself is sewn together in pieces. A typical 26 foot high velocity cargo parachute is provided with 26 suspension lines. Much of the expense incurred in the manufacture of such parachutes is devoted to the many feet of lines used and the sewing together of small pieces of cloth and reinforcement tapes. Typically a parachute of this type must be vented so as to survive high opening forces at altitudes of 25,000 feet, or more. Present technology requires labor intensive methods to accomplish this.
A simpler, less expensive, parachute is a “cross chute” which includes two rectangular pieces of cloth sewn together in a cross shape. The stitching is simplified in a cross chute inasmuch as the stitching is principally in a straight line and larger pieces of fabric are joined together. Still, the cross chute requires many suspension lines and many reinforcement lines on the canopy.
Both types of parachutes utilize canopies which traditionally are of nylon, which usually is produced in 5 foot wide strips. The nylon pieces must be sewn together and reinforced with lines and tapes.
Considering that most parachutes are used only once in delivery of humanitarian and military supplies, it is deemed necessary that there be made available a much less expensive cargo parachute which offers acceptable performance.
Accordingly, an object of the invention is to provide a low cost parachute for cargo airdrops.
With the above and other objects in view, a feature of the invention is the provision of a parachute comprising a plurality of first strips of fabric adapted to define a pattern wherein the first strips are separated from each other and extend parallel to each other, and a plurality of second strips of fabric adapted to further define the pattern wherein the second strips are separated from each other and extend parallel to each other and normal to the first strips, the number of the second strips being equal to the number of the first strips. The first and second strips cross each other at center portions thereof and thereby define vent holes. The ends of the strips are connected to suspension lines which are extendible to a confluence area.
The above and other features of the invention, including various novel details of construction and combinations of parts, will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular parachutes embodying the invention are shown by way of illustration only and not as limitations of the invention. The principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the invention.
Reference is made to the accompanying drawings in which are shown illustrative embodiments of the invention, from which its novel features and advantages will be apparent.
In the drawings:
Referring to
As shown in
In an embodiment provided to replace a prior art round 26 foot high velocity cargo chute (not shown), the strips 16, 18 preferably are three feet wide and fifty-one feet long. Inasmuch as woven polypropylene is produced in strips of three feet width, the stock material does not have to be sewn together to form larger pieces. The strips are cut to a desired length. The edges of the strips are finished during the making of the standard fabric used, and are strong enough to withstand tearing without the use of reinforcement lines or tapes. The woven polypropylene material exhibits a tear resistance of 40 to 65 pounds, whereas commonly used nylon exhibits a tear resistance of 5 to 10 pounds.
As best shown in
The strips 16, 18 are sewn together at the areas of their crossing each other. Aside from this sewing, there is no sewing in the entire canopy.
The suspension lines 12 are ropes, each tied to a strip end 22 by a self-tightening slip knot 24 that extends around the strip end gathered fabric. One suspension line 12 is tied to each strip end. Thus, the parachute presented herein in
Referring to
Thus, the parachute illustrated in
Referring to
The designs described above are scaleable and can be applied to smaller (
Tests of the parachute shown in
A parachute attached to a 1,500 pound load was dropped at 5,000 feet. The drop was successful. No damage to the parachute was experienced and a descent rate of 70 ft/sec. was observed. The desired range for high velocity cargo drops is 70–90 ft/sec.
The same parachute attached to a 2,200 pound load was dropped at 15,000 feet. The drop was successful. No damage to the parachute was experienced and the descent rate was clocked at 75 ft/sec.
The same parachute attached to a 2,200 pound load was dropped at 18,000 feet. The drop was successful. No damage to the parachute was observed. The descent rate was 70 ft/sec.
A newly fabricated parachute attached to a 2,200 pound load was dropped from an altitude of 25,000 feet. The drop was successful. Minor damage to one strip was noted. The descent rate was 75 ft./sec.
The parachute from the last drop was repaired and attached to a 2,200 pound load and dropped from 25,000 feet. The drop was successful.
Each drop was from a C-130 aircraft over the Yuma Proving Grounds. Subsequently, about 20 more successful air drops have been conducted at max load at 25,000 feet. One drop of the chute shown in
The combined features of the above-described parachute allow the parachute to be produced for from one third to one half the cost of the standard round cargo parachute and provides a reduced impact velocity.
Referring to
The load spreaders 17 are constructed of two pieces of nylon welding with a loop formed in each end. The load spreaders are bound together in an X pattern, providing four spaced end loops, through which pass the lines 12 extending to the D-rings 15. This arrangement permits the lines to adjust to a tumbling article 19 and to the proper opening of the parachute when carrying an article with uneven loading.
There is thus provided a new parachute providing a new geometry and a new method of construction. The new parachute is very low in costs, both in terms of materials and cost of production. The design remains applicable to scaled-up and scaled-down versions.
It will be apparent that when packed or deployed the parachute will not be laid out in the planar fashion shown in
It is to be understood that the present invention is by no means limited to the particular constructions herein disclosed and/or shown in the drawings, but also comprises any modification or equivalent within the scope of the claims.
The invention described herein may be manufactured and used by the U.S. Government for Governmental purposes without the payment of any royalty thereon.
Number | Name | Date | Kind |
---|---|---|---|
2745615 | Fogal | May 1956 | A |
3104856 | Knacke et al. | Sep 1963 | A |
3127137 | Downing | Mar 1964 | A |
3252676 | Frieder | May 1966 | A |
3331573 | Winker et al. | Jul 1967 | A |
3531067 | Mitchell | Sep 1970 | A |
4664342 | Jones | May 1987 | A |
4834323 | Reuter | May 1989 | A |
5082210 | Morehead | Jan 1992 | A |
5839695 | Puskas | Nov 1998 | A |
6443396 | Berland | Sep 2002 | B1 |
Number | Date | Country | |
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20050178917 A1 | Aug 2005 | US |