U.S. patent application number 09/734244 was filed with the patent office on 2002-06-13 for deforming charge assembly and method of making same.
Invention is credited to Grigsby, William H. JR., Gripshover, Robert J., Hannick, John W., Landman, Charles W..
Application Number | 20020069784 09/734244 |
Document ID | / |
Family ID | 24950873 |
Filed Date | 2002-06-13 |
United States Patent
Application |
20020069784 |
Kind Code |
A1 |
Landman, Charles W. ; et
al. |
June 13, 2002 |
DEFORMING CHARGE ASSEMBLY AND METHOD OF MAKING SAME
Abstract
A deforming charge assembly is provided which has an inner and
an outer cylinder formed from carbon fiber. Each of the inner and
outer cylinders have an inner circumferential surface having an
inner diameter, and that outer circumferential surface having an
outer diameter. The inner diameter of the outer cylinder is greater
than the outer diameter of the inner cylinder. Each of the inner
and outer cylinders have a first layer of circumferentially wound
carbon fiber, a second layer of unidirectional carbon fiber sheet
and a plurality of layers of carbon fibers circumferentially
wrapped around the second layer. A plurality of sympathetic
detonation barrier members are provided and have an inner surface
in contact with the outer circumferential surface of the inner
cylinder and an outer surface in contact with the inner
circumferential surface of the outer cylinder. The deforming charge
assembly is formed by the method of circumferentially winding a
carbon fiber around an inner mandrel to form a first layer of the
inner cylinder, wrapping a unidirectional carbon sheet around the
first layer of the inner cylinder to form a second layer of the
inner cylinder, circumferentially winding a carbon fiber around the
second layer of the inner cylinder to form a plurality of outer
layers, coating the inner cylinder with epoxy resin, positioning an
outer mandrel around the inner cylinder and in contact therewith,
which outer mandrel has slots extending from one end of the outer
mandrel towards the other end of the outer mandrel, positioning a
steel sympathetic detonation barrier strip and strips of Teflon on
each side of the barrier strip in each of the slots in the outer
mandrel, circumferentially winding a carbon fiber around the outer
mandrel to form a first layer of an outer cylinder, wrapping a
unidirectional carbon sheet around the first layer of the outer
cylinder to form a second layer of the outer cylinder,
circumferentially winding a carbon fiber around the second layer of
the outer cylinder to form a plurality of outer layers, coating the
outer cylinder with epoxy resin, and removing the outer mandrel
from between the inner and outer cylinders and the inner mandrel
from the inner cylinder.
Inventors: |
Landman, Charles W.;
(Callao, VA) ; Grigsby, William H. JR.;
(Fredericksburg, VA) ; Gripshover, Robert J.;
(King George, VA) ; Hannick, John W.; (King
George, VA) |
Correspondence
Address: |
James B. Bechtel, Esq.
NSWCDD (CD222)
Dahlgren
VA
22448-5100
US
|
Family ID: |
24950873 |
Appl. No.: |
09/734244 |
Filed: |
December 11, 2000 |
Current U.S.
Class: |
102/331 |
Current CPC
Class: |
F42B 12/76 20130101;
C06B 45/00 20130101 |
Class at
Publication: |
102/331 |
International
Class: |
F42B 003/00; F42D
003/00; F41A 009/00 |
Goverment Interests
[0001] The invention described herein may be manufactured and used
by or for the Government of the United States of America for
governmental purposes without the payment of any royalties thereon
or therefor.
Claims
The invention claimed:
1. A deforming charge assembly comprising an inner and an outer
cylinder formed from carbon fiber, each of said inner and outer
cylinders having an inner circumferential surface having an inner
diameter and that outer circumferential surface having an outer
diameter, said inner diameter of said outer cylinder is greater
than said outer diameter of said inner cylinder, each of said inner
and outer cylinders having a first layer of circumferentially wound
carbon fiber, a second layer of unidirectional carbon fiber sheet
and a plurality of layers of carbon fibers circumferentially
wrapped around said second layer, a plurality of sympathetic
detonation barrier members having an inner surface in contact with
said outer circumferential surface of said inner cylinder, said
barrier members having an outer surface in contact with said inner
circumferential surface of said outer cylinder.
2. The deforming charge assembly of claim 1 wherein said
sympathetic detonation barrier members are formed from 304
stainless-steel.
3. The deforming charge assembly of claim 1 wherein said
sympathetic detonation barrier members are about 0.125 inches
thick.
4. The deforming charge assembly of claim 1 wherein at least one of
said inner and outer cylinders have a wall thickness of about 0.05
inches.
5. The deforming charge assembly of claim 1 wherein the difference
between said outer diameter of said inner cylinder and said inner
diameter of said outer cylinder is about 0.285 inches.
6. The deforming charge assembly of claim 1 wherein said barrier
members adjacent each other and said outer circumferential surface
of said inner cylinder extending between said adjacent barrier
members and said inner circumferential surface of said outer
cylinder extending between said adjacent barrier members forming an
annular cavity.
7. The deforming charge assembly of claim 6 which includes an
explosive in said annular cavity.
8. A method for making a deforming charge assembly comprising the
steps of: circumferentially winding a carbon fiber around an inner
mandrel to form a first layer of an inner cylinder, wrapping a
unidirectional carbon sheet around the first layer of the inner
cylinder to form a second layer of the inner cylinder,
circumferentially winding a carbon fiber around the second layer of
the inner cylinder to form a plurality of outer layers, coating the
inner cylinder with epoxy resin, positioning an outer mandrel
around the inner cylinder and in contact therewith, which outer
mandrel has slots extending from one end of the outer mandrel
towards the other end of the outer mandrel, positioning a steel
sympathetic detonation barrier strip and strips of plastic on each
side of the barrier strip in each of the slots in the outer
mandrel, circumferentially winding a carbon fiber around the outer
mandrel to form a first layer of an outer cylinder, wrapping a
unidirectional carbon sheet around the first layer of the outer
cylinder to form a second layer of the outer cylinder,
circumferentially winding a carbon fiber around the second layer of
the outer cylinder to form a plurality of outer layers, coating the
outer cylinder with epoxy resin, removing the outer mandrel from
between the inner and outer cylinders and the inner mandrel from
the inner cylinder.
9. The method for making the deforming charge assembly of claim 8
which includes securing a circular clamp around the outer mandrel
and in contact with the steel sympathetic detonation barrier strips
and the strips of plastic in the slots of the outer mandrel after
the step of positioning the barrier strips and strips of plastic in
the slots in the outer mandrel.
10. The method for making the deforming charge assembly of claim 9
which includes removing the circular clamp during circumferentially
winding the carbon fiber around the outer mandrel as the first
carbon fiber approaches the clamp.
11. The method for making the deforming charge assembly of claim 8
which includes heating the inner and outer cylinders to cure the
epoxy resin after coating the outer cylinder with epoxy resin.
12. The method for making the deforming charge assembly of claim 8
which includes removing the plastic strips after removing the outer
mandrel from between the inner and outer cylinders in the inner
mandrel from the inner cylinder.
13. The method for making the deforming charge assembly of claim 12
which includes securing the ends of the deforming charge assembly
after removing the plastic strips.
14. The method for making the deforming charge assembly of claim 8
which includes extruding an explosive between the inner and outer
cylinders after removing the outer mandrel from between the inner
and outer cylinders and the inner mandrel from the inner
cylinder.
15. The method for making the deforming charge assembly of claim 8
which includes rotating the deforming charge assembly after
removing the outer mandrel from between the inner and outer
cylinders and the inner mandrel from the inner cylinder.
16. The method for making the deforming charge assembly of claim 8
which includes heating the deforming charge assembly after removing
the outer mandrel from between the inner and outer cylinders and
the inner mandrel from the inner cylinder.
Description
BACKGROUND OF INVENTION
[0002] The present invention relates to a deforming charge assembly
and method of making same and more particularly to a deforming
charge assembly which reduces the danger of explosion by the charge
assembly.
[0003] Ordinance items such as loaded charge assemblies, for
example those used in rocket motors, warheads and bombs, present an
extreme hazard in the event of "cook off" which is defined for
purposes of the subject application as detonation or deflagration
of the main explosive charge of the item due to an accidental fire.
The transportation and storage of charge assemblies, loaded with an
explosive, frequently requires placing them in environments which
have a high probability of being in the proximity of open flames.
For example, loaded charge assemblies are frequently placed on the
flight deck of a naval ship where an aircraft fuel tank is also
present. If accidental rupture of the fuel tank occurs, fuel
spreads over the flight deck. A fire that results upon ignition of
the spilled fuel can subject the loaded charge assemblies to high
temperatures along with a high risk of ignition of the explosive
material in the charge assemblies. The rapid internal pressure
buildup in the loaded charge assemblies will result in case rupture
and explosion with catastrophic results, including costly equipment
losses and potential loss of life.
[0004] Efforts have been made to modify charge assemblies to
preclude explosive behavior of the charge assembly when loaded with
an explosive material or to extend the time prior to violent
reaction of the loaded charge assembly to a fire. It is desirable
to provide an economical, reliable and tailorable charge assembly
which provides the necessary structural integrity under normal
conditions essential to its primary mission, while allowing
structural degradation when the assembly reaches a predetermined
abnormally elevated temperature which is below the auto ignition
temperature of the explosive in the charge assembly. Such a charge
assembly design renders the loaded charge assembly incapable of
sustaining sufficient internal pressure to destructively detonate
the charge assembly.
[0005] With the advent of plastic and other fibers, various
materials have been used to form ordinance devices. For example,
U.S. Pat. No. 2,872,865 discloses a woven fiber glass sleeving
impregnated with plastic material. U.S. Pat. No. 5,369,955 shows a
filament of polyolefin or polyethelene wound on a mandrel in a
number of plies and impregnated with a matrix material curable by
radiation. U.S. Pat. No. 5,170,007 discloses a sheet of material
woven from a composite fiber reinforced thermoplastic, such as
polyethersulfonegraphite fiber, rolled into a cylinder. An
adhesive, having a breakdown temperature less than the autoignition
temperature of the propellant in the cylinder, is used to hold the
sheet in the cylindrical form and release before the propellant
reaches its autoignition temperature.
[0006] U.S. Pat. No. 5,035,180 discloses an ordinance venting
system having a number of holes in the ordinance casing covered by
thermal metallic patches which expand at a different rate than the
casing and open the vent holes when subjected to heat.
[0007] U.S. Pat. No. 3,992,997 shows an insulated warhead casing
having a metallic tube surrounded by an ablative material such as
cork, carbon or TEFLON and an outer fire resistant layer of glass
fiber material impregnated with curable epoxy adhesive. U.S. Pat.
No. 5,125,179 teaches a gun barrel formed from a ceramic material
sections surrounded by an outer sleeve of braided graphite
composition structure or a graphite fiber/epoxy composite wrapped
about the ceramic sections. Other warhead designs used a graphite
epoxy material, wound in a thin cylinder, to contain an explosive
billet which is removed during depot maintenance of the
missile.
[0008] U.S. Pat. No. 4,646,615 discloses a barrel section for a
lightweight firearm manufactured by positioning epoxy treated
carbon fibre rovings in grooves in a mandrel with an inner mandrel
supporting the rovings which are at a slight helical angle to form
the rifling of the barrel. The grooves have a slight narrowing
towards the center of the barrel to facilitate removal of the
grooved mandrel after formation of the barrel. A carbon fibre
material treated with an epoxy resin is then wound around the
mandrels and rovings in the desired angle and layers. Preferably
the first four layers are hoop wound at a helix angle as close to
90 degrees as possible within the remaining layers wound according
to a formula.
[0009] Deforming charge assemblies of the type provided by the
present invention have been made with strips of relatively
insensitive Dupont LF-2 Detasheet, separated by sympathetic
detonation barriers, applied around the portion of the warhead
circumference on the side to be deformed. In a system application,
Detasheet would be placed around the entire warhead. The number of
strips and barriers would be determined by the number of firing
directions that a candidate system could support. The barrier would
confine the detonation to those sectors specifically selected by
the target detection device (TDD), and fired and initiated by the
electronic safe arm device (ESAD) and the warhead initiation system
(WIS).
[0010] Safety requirements dictated that an insensitive form of
Detasheet be used in any tactical system. When the insensitive LF-2
Detasheet became unavailable, alternate designs using insensitive
explosive as a means of deforming the warhead had to be devised.
More sensitive Detasheet was available and could be used to
complete development, but it was too sensitive for tactical
applications. Also, when producibility and depot maintenance were
considered, the use of discrete strips of Detasheet with barriers
between them was not an acceptable design. Graphite-epoxy
materials, wound in a thin cylinder, have been used to contain
explosive billets which are removed during depot maintenance of the
missile.
[0011] It is therefore an object to provide a deforming charge
assembly loaded with an explosive that can be sized to duplicate
the performance characteristics of Detasheet and which resolves the
problems inherent with separate pieces of Detasheet and barriers.
It is a further object to provide a deforming charge assembly that
may be efficiently mass produced and that may be efficiently
explosively loaded by the extrusion process. It is a further object
to provide a graphite housing of the deforming charge assembly to
aid in meeting Insensitive Munitions (IM) requirements.
SUMMARY OF THE PRESENT INVENTION
[0012] The present invention provides a deforming charge assembly
which as an inner and an outer cylinder formed from carbon fiber.
Each of the inner and outer cylinders have an inner circumferential
surface having an inner diameter, and an outer circumferential
surface having an outer diameter. The inner diameter of the outer
cylinder is greater than the outer diameter of the inner cylinder.
Each of the inner and outer cylinders have a first layer of
circumferentially wound carbon fiber, a second layer of
unidirectional carbon fiber sheet and a plurality of layers of
carbon fibers circumferentially wrapped around the second layer. A
plurality of sympathetic detonation barrier members are provided
and have an inner surface in contact with the outer circumferential
surface of the inner cylinder and an outer surface in contact with
the inner circumferential surface of the outer cylinder which form
a plurality of annular cavities.
[0013] The deforming charge assembly is formed by the method of
circumferentially winding a carbon fiber around an inner mandrel to
form a first layer of the inner cylinder, wrapping a unidirectional
carbon sheet around the first layer of the inner cylinder to form a
second layer of the inner cylinder, circumferentially winding a
carbon fiber around the second layer of the inner cylinder to form
a plurality of outer layers, coating the inner cylinder with epoxy
resin. The outer mandrel is then positioned around the inner
cylinder and in contact therewith. The outer mandrel has slots
extending from one end of the outer mandrel towards the other end
of the outer mandrel. Steel sympathetic detonation barrier strips
and strips of TEFLON on each side of the barrier strip are
positioned in each of the slots in the outer mandrel. The method
then provides for circumferentially winding a carbon fiber around
the outer mandrel to form a first layer of an outer cylinder,
wrapping a unidirectional carbon sheet around the first layer of
the outer cylinder to form a second layer of the outer cylinder,
circumferentially winding a carbon fiber around the second layer of
the outer cylinder to form a plurality of outer layers, coating the
outer cylinder with epoxy resin, and removing the outer mandrel
from between the inner and outer cylinders and the inner mandrel
from the inner cylinder.
[0014] An explosive, such as PBXW-128, is injection loaded into the
annular cavities and is sized to duplicate the performance
characteristics of Detasheet which resolves the problems inherent
with separate pieces of Detasheet and barriers. The present
invention provides a deforming charge assembly which may be
efficiently mass produced and that may be efficiently explosively
loaded by the extrusion process. A deforming charge assembly is
also provided by the present invention having a graphite housing
which aids in meeting Insensitive Munitions (IM) requirements. In
addition to light weight and strength, graphite material is
electrically conductive, thereby eliminating the electrostatic
hazard often associated with composites and explosives.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a perspective view of the deforming charge
assembly of the present invention,
[0016] FIG. 2 is a partial sectional view of the deforming charge
assembly shown in FIG. 1 and taken along line 2-2 thereof,
[0017] FIG. 3 is a partial sectional view of the deforming charge
assembly shown in FIG. 1 and taken along line 3-3 thereof,
[0018] FIG. 4 is a partial sectional view of the deforming charge
assembly shown in FIG. 3 and taken along line 4-4 thereof,
[0019] FIG. 5 is a perspective view of the inner and outer mandrels
used to form the deforming charge assembly of the present invention
and a hose clamp, and
[0020] FIG. 6 is a partial sectional view of the outer mandrel
shown in FIG. 5 with a sympathetic detonation barrier of the
deforming charge assembly positioned therein.
DETAILED DESCRIPTION OF THE INVENTION
[0021] The present invention provides a deforming charge assembly
10 which has an inner and an outer cylinder 12, 14 respectively,
formed from carbon fiber 16 as seen in FIGS. 1-4. Each of the inner
and outer cylinders 12, 14 have an inner circumferential surface
18, 20 respectively having an inner diameter 22, 24 respectively,
an outer circumferential surface 26, 28 respectively having an
outer diameter 30, 32 respectively. The inner diameter 24 of the
outer cylinder 14 is greater than the outer diameter 30 of the
inner cylinder 12 and in a preferred design is about 0.57 inches
greater.
[0022] Each of the inner and outer cylinders 12, 14 have a first
layer 34, 36 respectively of circumferentially wound carbon fiber
16, a second layer of 38, 40 of unidirectional carbon fiber sheet
and four outer layers 42, 44, 46, 48; 50, 52; and 54, 56
respectively of carbon fibers 16 circumferentially wrapped around
the second layer 38, 40. The layers 34, 38, 42, 46, 50 and 54
extend between the ends 56, 58 of the inner cylinder 12 and the
layers 36, 40, 44, 48, 52 and 56 extend between the ends 57, 59 of
the outer cylinder 14. The carbon fiber 16 to form the cylinders
12, 14, is light weight, high strength, and is electrically
conductive, thereby eliminating the electrostatic hazard often
associated with composites and explosives. Preferably, the
cylinders are made of an AS4 carbon fiber.
[0023] A plurality of sympathetic detonation barrier members 60 are
provided and have a generally rectangular crossectional
configuration and have an inner surface 62, an outer surface 64,
and side surfaces 66. The inner surface 62 is in contact with the
outer circumferential surface 26 of the inner cylinder 12 and its
outer surface 64 is in contact with the inner circumferential
surface 20 of the outer cylinder 14. A number of barrier members 60
are positioned around the space between the inner and outer
cylinders 12,14 as described above. The side surfaces 66 of
adjacent barrier members 60, the outer circumferential surface 26
of the inner cylinder 12 and the inner circumferential surface 20
of the outer cylinder 14 between the adjacent barrier members form
annular cavities or apertures 68 about the cylinders 12, 14. The
annular cavities or apertures 68 are filled with an explosive 70 as
will be more fully described. In a preferred design, the radial
distance between the outer circumferential surface of the inner
cylinder and the inner surface of the outer cylinder is about 0.285
inches.
[0024] The number of firing directions which could be supported by
a system dictate the number of strips and barriers 60 which are
used. Testing has been conducted to determine what material the
sympathetic detonation barrier members 60 should be made of, and
how much of it, had to be placed between the sectors of inner and
outer cylinders 12, 14 so that one strip would not sympathetically
detonate an adjacent one. The best material was determined to be
the most dense, and tungsten emerged as the first choice, followed
by lead and steel. Although barriers of tungsten or lead would be
less thick than those made of steel, the cost and environmental
effects of using either of those materials outweighed the savings.
Therefore, steel was chosen for the barriers. In the preferred
design, the sympathetic detonation barriers 60 are fabricated from
304 stainless steel, and are 0.125 inches thick, that is the
distance between the side surfaces 66, which is a conservative
design for the standard PBXW-128 explosive 70 with 77% HMX content
used to load the annular cavities of apertures 68 about the
cylinders 12, 14.
[0025] The cylinders 12, 14 and the sympathetic detonation barrier
members 60 are formed as a unitary structure with an epoxy 72, such
as EPON 8132/Teta hardener epoxy system, binding the carbon fiber
16 and the unidirectional carbon fiber sheet 38, 40 forming the
inner and outer cylinders 12, 14 respectively. The method of
forming the inner and outer cylinders 12, 14 is described below and
the use of the epoxy 72 is more fully described. The deforming
charge assembly 10 of the present invention is formed with an inner
and outer mandrel 74, 76 respectively, as shown in FIGS. 5 and 6.
The inner cylinder 12 is manufactured first. To form the inner
cylinder 12, the inner mandrel 74 is mounted on a winding machine
such as and a four axis filament winding machine manufactured by
Engineering Technology Co., Salt Lake City, Utah. The inner mandrel
74 has a generally cylindrical shape. The first layer 34 of the
inner cylinder 12 is formed by circumferentially winding a carbon
fiber 16, such as a dual carbon fiber wrap manufactured by Thornel,
product number T300 6K, around the outer circumferential surface 77
of the inner mandrel 74 to form the first layer 34 as shown in FIG.
4.
[0026] The second layer 38 is formed by wrapping a unidirectional
carbon sheet, such as that manufactured by Hexel, part No. S6565,
around the first layer 34 of the inner cylinder 12 to form the
second layer 38 of the inner cylinder and is provided for
longitudinal strength of the inner cylinder 12. The third, fourth,
fifth and sixth layers 42, 46, 50 and 54 respectively of the inner
cylinder 12 are formed on the four axis filament winding machine by
circumferentially wrapping the third layer 42 around the second
layer 38, then circumferentially wrapping the fourth layer 46
around the third layer 42, then circumferentially wrapping the
fifth layer 50 around the fourth layer 46 and then
circumferentially wrapping the sixth layer 54 around the fifth
layer 50.
[0027] The third through six layers, 42, 46, 50 and 54, sue the
same T300 6K wrap as in the first layer 34, for a typical total
thickness of the inner cylinder 12 of about 0.050 inches. The inner
mandrel 74, carbon fiber wraps 34, 42, 46, 50 and 54, and the
unidirectional sheet 38 are then liberally coated with epoxy resin
72, manufactured by Shell Oil Co., part no. EPON 8132 mixed with an
appropriate curing agent such as Shell's Epi-Cure 3046.
[0028] The outer mandrel 76, as shown in FIGS. 5 and 6, and has a
generally cylindrical shape with inner and outer circumferential
surfaces 78, 80 respectively. The inner circumference 82 of the
outer mandrel 76, and consequently the diameter of its inner
surface 78 is equal to the circumference of the outer circumference
26 of the inner cylinder 12 and its diameter 30. The outer
circumference 84 of the outer mandrel 76, and consequently the
diameter of its outer surface 80 is equal to the circumference of
the inner circumference 20 of the outer cylinder 14 and its
diameter 24.
[0029] To position the sympathetic detonation barriers 60 between
the inner and outer cylinders 12, 14, the outer mandrel 76 has a
series of slots 86 about its periphery 88 and positioned
therearound to position the sympathetic detonation barriers 60
where desired. As seen in FIGS. 5 and 6 plastic strips 90, such as
TEFLON, are provided for allowing removal of the outer mandrel 76
after the deforming charge assembly 10 is formed as will be
hereinafter described.
[0030] The outer mandrel 76 is positioned around the inner cylinder
12 with its inner circumferential surface 78 adjacent to the outer
circumference 26 of the inner cylinder 12. The sympathetic
detonation barriers 60 are then positioned in each of the slots 86
of the outer mandrel 76 with the plastic strips 90 positioned
between the mandrel slot 86 and the sympathetic detonation barrier.
Each of the slots 86 has opposing inner sides 92 which are spaced
from each other a sufficient distance to receive a sympathetic
detonation barrier 60 with a plastic strip 90 on each side of the
barrier 60.
[0031] The entire assembly of the inner mandrel 74, inner cylinder
12, outer mandrel 76, sympathetic detonation barriers 60 and
plastic strips 90 is bolted together on the wrapping machine. Prior
to starting the manufacture of the outer cylinder 14, the outer end
94 of the outer mandrel 76 is encircled with a stainless steel
aircraft type circular hose clamp 96 which contacts the steel
sympathetic detonation barriers 60 and plastic strips 90 in the
slots 86 and holds them in proper alignment. The hose clamp 96 is
removed s the first carbon fiber wrap approaches the clamp.
[0032] The outer cylinder 14 is manufactured in the same manner as
the inner cylinder 12, using the same products and winding machine.
To form the outer cylinder 14, first layer 36 of the inner cylinder
14 is formed by circumferentially winding a carbon fiber 16, such
as a dual carbon fiber wrap manufactured by Thornel, product number
T300 6K, around the outer mandrel 76. The circular or hose clamp 96
is removed as the first carbon fiber 16 approaches the clamp.
[0033] The second layer 40 is formed by wrapping a unidirectional
carbon sheet, such as that manufactured by Hexel, part No. S6565,
around the first layer 36 of the outer cylinder 14 to form the
second layer 40 of the outer cylinder and is provided for
longitudinal strength of the outer cylinder 14. The third, fourth,
fifth and sixth layers 44, 48, 52 and 56 respectively of the outer
cylinder 14 are formed on the four axis filament winding machine by
circumferentially wrapping the third layer 44 around the second
layer 40, then circumferentially wrapping the fourth layer 48
around the third layer 44, then circumferentially wrapping the
fifth layer 52 around the fourth layer 48 and then
circumferentially wrapping the sixth layer 56 around the fifth
layer 52.
[0034] The third through six layers 44, 48, 52 and 56, use the same
T300 6K wrap as in the first layer 36, for a typical total
thickness of the outer cylinder 14 of about 0.050 inches. The outer
mandrel 76, carbon fiber wraps 36, 44, 48, 52 and 56, and the
unidirectional sheet 40 are then liberally coated with epoxy resin,
manufactured by Shell Oil Co., part no. EPON 8132 mixed with an
appropriate curing agent such as Shell's Epi-Cure 3046.
[0035] After wrapping, the assembly is allowed to rotate slowly to
prevent the resin from sloughing off the cylinders 12, 14 until it
gels. The entire assembly is removed from the winding machine and
placed in an oven at a temperature and for a sufficient time for
the epoxy to cure. Using the preferred materials described herein,
the assembly 10 is placed in an oven for four hours at 212.degree.
F. temperature to cure. After the epoxy resin is cured, the
assembly 10 is then allowed to cool to ambient (room) temperature
for the remainder of the day and over night.
[0036] The mandrels 74, 76 and then using a specially made fixture,
since the force required is usually very large. This is an
important step, since the deforming charge assembly 10 can be
destroyed by the force required for removing the mandrels. Finally,
the plastic strips 90 are removed by hand using a screw driver as a
probe and the ends 56, 58 of the inner cylinder 12, the ends 57, 59
of the outer cylinder 14, and the sympathetic detonation barriers
60 of the assembly 10 are dressed by hand, using emery cloth and a
sanding block. The deforming charge assembly 10 is then injection
loaded with PBXW-128 explosive. When ready to use the deforming
charge assembly 10, detonators, such as RP-80 detonators, are
installed.
[0037] The invention has been described with reference to the
preferred embodiments. Obviously, modifications and alterations
will occur to others upon reading and understanding this
specification. It is intended to include all modifications and
alterations insofar as they come within the scope of the appended
claims or equivalents thereof.
* * * * *