U.S. patent number 3,675,577 [Application Number 04/380,117] was granted by the patent office on 1972-07-11 for rod warhead.
This patent grant is currently assigned to The United States of America as represented by the Secretary of the Navy. Invention is credited to Howard Katz, Dante Piacesi, Jr., Hyman M. Sternberg.
United States Patent |
3,675,577 |
Sternberg , et al. |
July 11, 1972 |
ROD WARHEAD
Abstract
1. An explosive warhead comprising, Inner and outer metallic
cylinders concentrically disposed about a common is, First and
second annular bodies of explosive material concentrically disposed
about said axis, Said first body being disposed within the inner
cylinder, Said second body being positioned radially between said
cylinders in contact with one of said cylinders and being radially
spaced from the other cylinder, and Means connected to the first
body for igniting the first body of explosive material prior to the
detonation of the second body of explosive material.
Inventors: |
Sternberg; Hyman M. (Silver
Spring, MD), Piacesi, Jr.; Dante (Silver Spring, MD),
Katz; Howard (Rockville, MD) |
Assignee: |
The United States of America as
represented by the Secretary of the Navy (N/A)
|
Family
ID: |
23499973 |
Appl.
No.: |
04/380,117 |
Filed: |
June 30, 1964 |
Current U.S.
Class: |
102/474 |
Current CPC
Class: |
F42B
12/22 (20130101); F42B 12/204 (20130101) |
Current International
Class: |
F42B
12/22 (20060101); F42B 12/20 (20060101); F42B
12/02 (20060101); F42b 013/48 () |
Field of
Search: |
;102/64,65,67,68,69 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Bentley; Stephen C.
Claims
What is claimed is:
1. An explosive warhead comprising,
inner and outer metallic cylinders concentrically disposed about a
common axis,
first and second annular bodies of explosive material
concentrically disposed about said axis,
said first body being disposed within the inner cylinder,
said second body being positioned radially between said cylinders
in contact with one of said cylinders and being radially spaced
from the other cylinder, and
means connected to the first body for igniting the first body of
explosive material prior to the detonation of the second body of
explosive material.
2. The explosive warhead of claim 1 wherein,
said outer cylinder comprises a bundle of elongated rods connected
together to form an expansion-linkage type of continuous rod
assembly, and
said second body of explosive material is in intimate contact with
the outer peripheral surface of the inner cylinder.
3. The explosive warhead of claim 2 further comprising an annular
body of low density foam material positioned within and completely
filling the annular space defined by said second body of explosive
material and the outer cylinder.
4. The explosive warhead of claim 1 further comprising,
first and second end caps disposed on opposite ends of said warhead
and fixedly secured to opposite ends of said inner and outer
metallic cylinders to define a closed chamber within said
warhead.
5. The explosive warhead of claim 1 wherein,
said outer cylinder is a continuous metallic cylinder having a
plurality of grooves formed therein to create weakened portions in
the outer cylinder to facilitate fragmenting thereof upon
detonation of the explosive material, and
said second body of explosive material is in intimate contact with
the inner peripheral surface of the outer cylinder.
6. The explosive warhead of claim 5 further comprising an annular
body of low density foam material positioned within and completely
filling the annular space defined by said second body of explosive
material and said inner cylinder.
7. The explosive warhead of claim 1 wherein said outer cylinder is
a continuous metallic cylinder having weakened portions therein to
facilitate fragmenting thereof upon detonation of the explosive
material, and
said second body of explosive material is in intimate contact with
the outer peripheral surface of the inner cylinder.
8. The explosive warhead of claim 7 further comprising an annular
body of low density foam material positioned within and completely
filling the annular space defined by the second body of explosive
material and the outer cylinder.
9. A two stage explosive warhead comprising,
a cylindrical metal tube,
a first annular body of explosive material filling said tube and
having a longitudinal axial bore formed therein,
a second annular body of explosive material concentrically
positioned about said tube and being in intimate contact with the
tube throughout the periphery thereof,
a plurality of rods interconnected to form an expansible-linkage
type or rod assembly,
said rod assembly being positioned around the second annular body
of explosive material,
support means for maintaining said rod assembly radially spaced
apart from the second annular body of explosive material, and
means mounted within said bore for initiating the first annular
body of explosive material,
whereby the rod assembly is radially expanded outwardly by the
gases of the explosion with high velocity.
10. The two stage explosive warhead of claim 9 further
comprising
an annular body of low density foam material positioned between the
inner peripheral surface of the rod assembly and the outer
peripheral surface of the second annular body of explosive material
and completely filling the space therebetween.
Description
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.
This invention relates to explosive warheads and more particularly
to a warhead adapted to be carried by a missile and constructed in
such a manner as to disperse a fragmenting casing or an
expansion-link type of continuous rod assembly with very high
velocities being imparted thereto.
It has been found that the damage caused to aircraft structures
decreases rapidly when the angle between the rod path and the
normal to the path of the target exceeds 50.degree.. When the
aircraft is struck a glancing blow by either a fragmenting casing
or a continuous rod assembly, the damage inflicted is substantially
less than the damage which might have been inflicted if the rod
path has been normal to the path of the target. Most modern
continuous rod warheads and fragmenting casing warheads have
expansion velocities in the order of 4,000 to 6,000 feet per
second, which is rather slow when it is considered that the closing
speed or relative speeds of the target and the missile in modern
warfare approaches 10,000 feet per second. Consequently, when using
conventional warheads having slow expansion velocities in
situations where the missile to target closing speeds approach
10,000 feet per second, the angle between the rod path and the
normal to the target path is undesirably large and the warheads are
therefore unable to inflict their optimum amount of damage upon the
target.
The use of a higher energy explosive in continuous rod warheads to
obtain these velocities is not feasible because higher pressures
would result in the rods and contribute to reduced continuity in
the continuous rod assembly. In fragmenting warheads, these higher
pressures could result in smaller sized fragments than desired. The
use of larger explosive charges in both fragmenting and continuous
rod warheads is not feasible because of warhead weight limitations.
The present invention, however, utilizes a unique design geometry
whereby the energy of the explosive material is more efficiently
transferred to the expanding materials and acts upon the expanding
materials in two stages to impart velocities to the fragmenting
casing or continuous rod assembly of magnitudes heretofore not
practically obtainable.
It is an object of the present invention to provide a continuous
rod warhead which, upon detonation, has high rod velocity and yet
maintains the continuity of the rod assembly.
Another object of the invention is to provide a continuous rod
warhead having an efficient transfer of energy from the explosive
material to the rod assembly whereby high rod velocities may be
obtained with smaller amounts of explosive than used in
conventional warheads and which is constructed in a manner to
eliminate problems of aerodynamic heating of the explosive
material.
A further object of the invention is to provide a fragmenting case
type of warhead capable of imparting high velocities to the
fragmenting materials.
Other objects, advantages and novel features of the invention will
become apparent from the following detailed description of the
invention when considered in conjunction with the accompanying
drawings wherein:
FIG. 1 is a view in elevation and partly broken away of a warhead
of the present invention in accordance with a preferred embodiment
thereof;
FIG. 2 is a sectional view taken along line 2--2 of FIG. 1;
FIG. 3 is a sectional view of a second embodiment of the present
invention; and
FIG. 4 is a sectional view of a third embodiment of the present
invention.
Referring now to FIGS. 1 and 2 of the drawings, there is shown a
continuous rod type warhead rod assembly shown generally at 10. The
warhead has a metallic tube 11 which receives the main body of the
explosive material 12. The explosive material 12 completely fills
the tubular member 11 with the exception of a through aperture
formed therein at the common axis of the tube 11 and the main
charge 12. The outer peripheral surface of tube 11 is coated with a
layer 13 of explosive material and the whole core of the warhead,
comprising the main charge 12, the tube 11, the layer of explosive
material 13 and a gas or foam filled space 22, is positioned within
an expansible link type of continuous rod assembly 10. The
continuous rod assembly may, for example, comprise a plurality of
rods arranged in a cylindrical bundle and positioned side by side
to one another and having the opposite ends of each rod welded or
otherwise secured to different adjacent rods. The rod assembly is
of substantially the same length of the core of the warhead but has
a diameter larger than the diameter of the explosive layer 13 and
is concentrically positioned about and radially spaced from the
core assembly and mounted thereto by means of a pair of end caps 15
and 16. The annular space or chamber defined by the concentrically
disposed explosive layer 13 and the continuous rod assembly 14 is
filled with a gas at a pressure near ambient or, if desired, may be
filled with a low density foam material 22, to provide an
additional means to control the loading of the continuous rod
assembly. Connected to the main charge is a conventional detonation
device 17, which may be positioned along the axis of the main
charge or at an end thereof and may be either a single or
multipoint detonator system, to initiate the explosion of the main
charge, which in turn causes the detonation of the annular charge
13.
In operation, when detonator 17 initiates the explosive of material
12, the detonation charge accelerates the inner metal tube 11
radially outwardly and the accompanying shock wave causes the
initiation of the outer explosive layer 13. When the gas from the
explosive layer first reaches the outer tube or continuous rod
assembly 10, the pressure within the annular space therebetween is
near ambient at the gas metal interface because the gas has been
expanding across the space. However, the pressure builds up rapidly
at the interface, thus producing a shock in the metal of the
continuous rod assembly which accelerates the rod assembly radially
outwardly. At the same time a shock wave is reflected back into the
gas in a radially inward direction. As this shock wave travels
radially inwardly it impinges upon the inner metal tube 11, which
is expanding radially outwardly under the pressures developed by
the main charge 12, and is again reflected and caused to travel in
a radially outward direction. The shock wave then moves radially
outwardly and impinges upon the inner surface of the continuous rod
assembly for a second time to further accelerate the rod assembly.
The first impact of the shock wave upon the inner peripheral
surface of the continuous rod assembly causes an acceleration of
the rod assembly in a radially outwardly direction and the second
impact of the reflected shock wave upon said inner peripheral
surface of the rod assembly causes a further acceleration in the
radially outwardly direction to import an even higher velocity to
the expanding rod assembly. By virtue of the construction of the
rod assembly 10, this assembly is capable of expanding to a
circumference almost equal to the combined length of the individual
rods in the rod assembly. The two stage warhead of the present
invention accelerates the continuous rod assembly by means of two
separate shock waves, each of which is of lesser magnitude than the
single shock wave of a single stage conventional warhead, and in so
doing maintains continuity of the expanding rod assembly while
imparting velocities much higher in magnitude than those able to be
developed by a conventional type of warhead while maintaining
continuity.
The two stage warhead of the present invention is capable of
imparting to the rod assembly velocities in the order of 12,000 to
14,000 feet per second, which is much larger than the velocities
obtainable in the same size conventional single stage warhead, and
produces these velocities with the use of peak pressures which are
35 to 55 percent lower than those pressures required in
conventional single stage warheads. Because the peak pressures are
so much lower than those in the conventional systems, preservation
of the continuity of the rod assemblies is more likely and it may
be seen that the design in the present invention would permit the
use of more powerful explosives and therefore lends more
versatility to the selection of the explosives employed.
Furthermore, the annular space between the rod assembly 10 and the
explosive layer 13 eliminates problems of aerodynamic heating of
the explosive material which are inherent in conventional guided
missile warhead systems and thereby lends further versatility in
the selection of the explosive material. The two stage warhead
expansion velocities of the order of 12,000 to 14,000 feet per
second insures a more favorable impact angle with the target and
therefore enables the warhead to deliver a more destructive blow to
the target. It should also be noted that the two stage warheads of
the present invention are usually about 40 percent lighter than
conventional single stage warheads.
This two stage system may also be employed in a warhead of the
fragmenting type such as shown in FIGS. 3 and 4 wherein the outer
casing 14, for example, may be a solid continuous cylindrical body
having weakened sections such as those formed by grooves in the
surface thereof so that, upon detonation of the explosive material,
the casing 14 will separate into fragments having a high velocity
of expansion, which fragments then disperse into a pattern for
collision with the target. If the particular explosive material
employed is of such a nature as to not be effected by aerodynamic
heating, the explosive material comprising the layer 21 may be
secured to the inner surface of the outer casing 14. If however the
layer 21 of explosive material is of a type which is sensitive to
heat, it should be secured to the outer peripheral surface of inner
metal tube 11, as shown in the FIG. 4 embodiment of the invention.
In either case, the annular space adjacent to the layer of
explosive material may be filled with a low density foam material,
if desired, to provide an additional means for controlling the
loading of the casing upon detonation. The two stage fragmenting
warhead shown in FIGS. 3 and 4 has a substantially better
efficiency of energy transfer from the explosive material to the
outer casing than does a conventional warhead, for reasons
explained in the operation of the embodiments disclosed in FIGS. 1
and 2.
As is seen from the foregoing, the two stage warhead of the present
invention provides means for controlling the loading of the
continuous rod assembly or, alternatively, the loading of the
fragmenting casing, i.e., the pressure-time history for the inner
surface of the rods. More specifically, the peak pressure developed
by the warhead may be manipulated by varying any one of the
following factors: the dimensions of the inner metal tube, the
dimensions of the explosive layer, the dimensions of the annular
void between the second stage explosive layer and the rod assembly,
or the particular explosive materials use in the warhead. It should
also be noted that the explosive material comprising the main
charge 12 may be a different explosive than that used in the second
stage charge, for example, in the embodiment of FIGS. 3 and 4 the
second stage explosive layer 21 may be selected of an explosive
which is insensitive to aerodynamic heating while the main
explosive charge 12 may be any explosive desired since it is
isolated from the aerodynamic heating.
The two stage warhead of this invention provides a very efficient
means for transferring energy from the explosive material to the
continuous rod assembly or to the fragmenting casing, whichever
type warhead is used, and therefore a guided missile warhead may be
40 percent lighter than a conventional single stage warhead but yet
will achieve expansion velocities much higher than those obtainable
with the conventional warheads. The two stage warhead creates the
high expansion velocities with peak pressures which are 35 to 55
percent lower than the peak pressures developed in conventional
systems, thus enhancing continuity of the rod assembly and enabling
the use of more powerful explosives if desired. The annular space
between the outer casing of the warhead and the second stage
explosive layer eliminates aerodynamic heating problems which are
inherent in conventional single stage systems, thus giving two
stage warhead a greater versatility in the selection of the
explosives employed. Furthermore, the high expansion velocities
obtainable with a two stage warhead guarantees a favorable impact
angle of the rod assembly with the target and therefore enables the
two stage warhead to inflict a much greater damage to high speed
targets than is possible with a single stage conventional
warhead.
Obviously many modifications and variations of the present
invention are possible in light of the above teachings. It is
therefore to be understood that within the scope of the appended
claims the invention may be practiced otherwise than as
specifically described.
* * * * *