| United States Patent Application |
20050178917
|
| Kind Code
|
A1
|
|
Bonaceto, Bruce
|
August 18, 2005
|
LOW COST PARACHUTE
Abstract
A parachute includes first strips of fabric configurable to define a
pattern wherein the first strips are separated from each other and extend
parallel to each other, and second strips of fabric configurable 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 first strips being equal to the number of second
strips. The first and second strips cross each other to define vent
holes. The ends of the strips are connected to suspension lines which are
extendible to a confluence area for support of an article of cargo.
| Inventors: |
Bonaceto, Bruce; (Southborough, MA)
|
| Correspondence Name and Address:
|
U.S. Army Soldier Systems Center
15 Kansas Street
Natick
MA
01760
US
|
| Serial No.:
|
779484 |
| Series Code:
|
10
|
| Filed:
|
February 12, 2004 |
| U.S. Current Class: |
244/145 |
| U.S. Class at Publication: |
244/145 |
| Intern'l Class: |
B64D 017/02 |
Goverment Interests
[0001] The invention described herein may be manufactured and used by the
U.S. Government for Governmental purposes without the payment of any
royalty thereon.
Claims
1. 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; 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; said first and second strips crossing
each other at center portions thereof and thereby defining vent holes,
said first and second strips and vent holes being arranged for providing
an opening of the parachute with low opening shock, and providing drag
for a rate of descent; and ends of said strips being connected to
suspension lines extendible to a confluence area.
2. The parachute in accordance with claim 1 wherein the fabric exhibits a
tear resistance greater than 30 pounds.
3. The parachute in accordance with claim 2 wherein the fabric exhibits a
tear resistance greater than 40 pounds.
4. The parachute in accordance with claim 3 wherein the fabric comprises
polypropylene with a tear resistance of 40-65 lbs.
5. The parachute in accordance with claim 1 wherein each of said strips in
plan view is generally rectangularly shaped, less said ends of said
strips connected to the suspension lines.
6. The parachute in accordance with claim 5 wherein said strips are sewn
to each other where said first strips cross said second strips.
7. The parachute in accordance with claim 6 wherein said strips define a
canopy devoid of reinforcing lines and tapes and devoid of sewing other
than where said strips are sewn to each other.
8. The parachute in accordance with claim 1 wherein said pluralities of
strips each comprise 2-5 strips.
9. The parachute in accordance with claim 8 wherein said pluralities of
strips each comprise three strips so as to define four vent holes.
10. The parachute in accordance with claim 9 wherein each of said strips
is about 3 feet wide and about 51 feet long.
11. The parachute in accordance with claim 8 wherein said pluralities of
strips each comprise 5 strips and each of said strips is about 5 feet
wide and about 90 feet long.
12. The parachute in accordance with claim 1 wherein the suspension lines
comprise ropes, each suspension line being tied to an end of a said
strip.
13. The parachute in accordance with claim 12 wherein one suspension line
is tied to each strip, and said suspension rope and said end of said
strip are tied together by a self-tightening knot that extends around
gather fabric at the strip end.
14. The parachute in accordance with claim 1 wherein the confluence area
comprises load spreaders and D-rings, and wherein the suspension lines
extend from the strip ends, through said load spreaders, and are attached
to said D-rings which, in turn, support an article of cargo.
15. A method for making a parachute, the method comprising the steps of:
arranging a plurality of first strips of high tear resistant material
extending parallel to each other and spaced from each other; arranging a
plurality of second strips of the material extending parallel to each
other and spaced from each other, and extending normal to the first
strips, with central portions of the first and second strips extending
across each other; attachably fixing the first and second strips together
where the first and second strips extend across each other; wherein the
first and second strips are of equal width and equal length and the
spacings thereof define vents, said first and second strips and vents
being arranged for providing an opening of the parachute with low opening
shock, and providing drag for a rate of descent; and fixing suspension
lines to ends of said strips, the suspension lines being extendible to a
common confluence area; and wherein the fixing of the suspension lines to
the ends of the strips comprises tying the suspension lines and the ends
of the strips together with self-tightening knots.
16. (canceled)
17. The method in accordance with claim 15 wherein the fixing together of
the first and second strips comprises stitching the first and second
strips together.
18. The method in accordance with claim 15 wherein the high tear resistant
material is woven polypropylene.
Description
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] 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.
[0004] 2. Description of the Prior Art
[0005] 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.
[0006] 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.
[0007] 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.
[0008] 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.
[0009] 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.
SUMMARY OF THE INVENTION
[0010] Accordingly, an object of the invention is to provide a low cost
parachute for cargo airdrops.
[0011] 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.
[0012] 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.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] 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.
[0014] In the drawings:
[0015] FIG. 1 is a perspective view of one form of parachute illustrative
of an embodiment of the invention;
[0016] FIG. 2 is a top view of a canopy portion of the parachute of FIG. 1
disposed in a plane;
[0017] FIG. 3 is similar to FIG. 2, but showing an alternative embodiment;
[0018] FIG. 4 is similar to FIGS. 2 and 3, but illustrative of another
alternative embodiment; and
[0019] FIG. 5 is similar to FIG. 1, but showing a further alternative
embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] Referring to FIG. 1, it will be seen that an illustrative parachute
includes a canopy 10 and suspension lines 12 fixed at one end to the
canopy 10 and extendible toward a confluence area 14.
[0021] As shown in FIG. 2, the canopy 10 is formed by a plurality of first
strips 16 of fabric, preferably woven polypropylene. The strips 16 are
separated from each other and extend parallel to each other. A plurality
of second strips 18 of the same fabric are separated from each other and
extend parallel to each other and are normal to the first strips 16.
[0022] 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.
[0023] As best shown in FIG. 2, the strips 16, 18 cross each other in the
center area of the canopy 10. Inasmuch as the strips 16 are separated
from each other, and the strips 18 are similarly separated, the strips
16, 18 form vents 20, which serve to relieve the canopy of excessive
forces which might damage the canopy or the article of cargo during
opening. The arrangement of strips and the vents formed thereby has been
found to provide gentle opening of the canopy with low opening shock, yet
provide sufficient drag for a desired rate of descent.
[0024] 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.
[0025] 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 FIGS. 1 and 2 requires twelve suspension
lines. The round 26 foot parachute referred to hereinabove requires 26
suspension lines and the aforementioned cross parachute generally
requires 20 suspension lines in this size. Chutes larger or smaller
require correspondingly fewer lines than prior art round or cross
parachutes. Inasmuch as the suspension lines 12 are tied to the strip
ends 22, there are no additional attaching loops, reinforcements, ties or
sewing for attachment of the suspension lines 12 to the canopy 10.
[0026] Referring to FIG. 3, it will be seen that a smaller version of the
parachute of FIGS. 1 and 2 includes two first strips 16A and two second
strips 18A. In this case, one vent 20A is provided and only eight
suspension lines are required.
[0027] Thus, the parachute illustrated in FIGS. 1, 2, and 3 enables the
use of stock widths of material without any reinforcement lines or tapes.
The suspension lines are reduced in number and require no canopy lines or
sewing for affixing the suspension lines. Aside from the area where the
strips 16, 18 cross, there is no required sewing in the canopy of the
present parachute.
[0028] Referring to FIG. 4, there is shown a low velocity version
featuring five first strips 16B and five second strips 18B, providing
sixteen vents 20B. In this embodiment, the strips preferably are 5 feet
wide and 90 feet long.
[0029] The designs described above are scaleable and can be applied to
smaller (FIG. 3) and larger (FIG. 4) parachutes to provide similar
performance at a lower cost. The widths and lengths of the strips can be
proportionally sized to fit larger and smaller chutes.
[0030] Tests of the parachute shown in FIGS. 1 and 2 have been conducted.
[0031] 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 decent rate of 70 ft/sec. was observed. The desired range for high
velocity cargo drops is 70-90 ft/sec.
[0032] 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 as
experienced and the decent rate was clocked at 75 ft/sec.
[0033] 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 as
observed. The decent rate was 70 ft/sec.
[0034] 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 decent rate was 75 ft./sec.
[0035] 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.
[0036] 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 FIG. 4 was
conducted with 1,000 lbs. and performed well at a descent rate of 21
ft/sec.
[0037] 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.
[0038] Referring to FIG. 5, it will be seen that the confluence area 14
may include D-rings 15, known in the art, and may include load spreaders
17. In the latter embodiment, each side of the canopy 10 is provided with
a bundle of lines 12 routed through the load spreaders 17, and thence to
the D-rings 15, which support an article 19 to be delivered. The lines 12
are fastened to the D-rings 15.
[0039] 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.
[0040] 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.
[0041] It will be apparent that when packed or deployed the parachute will
not be laid out in the planar fashion shown in FIGS. 2-4. However, in the
construction of the parachute the strips are arranged so that they are
adapted to define the patterns shown in FIGS. 2-4.
[0042] 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.
* * * * *