U.S. patent number 3,765,336 [Application Number 05/221,498] was granted by the patent office on 1973-10-16 for chaff bullet.
This patent grant is currently assigned to The United States of America as represented by the Secretary of the Navy. Invention is credited to Robert J. Kulsik.
United States Patent |
3,765,336 |
Kulsik |
October 16, 1973 |
CHAFF BULLET
Abstract
A chaff bullet having a nose piece, a body and a rear section.
The body eoses a chaff element which comprises a pair of half
shells, each tapered at one end, and a plurality of chaff packettes
positioned within the half shells. Each chaff packette includes
several thousand elongated chaff which are enclosed by a thin
wrapping of Mylar. When the chaff bullet is fired from a gun the
tracer powder contained in the rear section burns slowly. After a
predetermined time the increasing heat from the burning tracer
powder causes ignition of an explosive in the body section which
forces out the chaff element. The spin of the bullet causes outward
release of the half shells and the chaff packettes. When the chaff
packettes enter the air stream the Mylar wrapping is unwrapped
which releases the chaff into the air in a well dispersed and
undamaged condition.
Inventors: |
Kulsik; Robert J. (Livermore,
CA) |
Assignee: |
The United States of America as
represented by the Secretary of the Navy (Washington,
DC)
|
Family
ID: |
22828073 |
Appl.
No.: |
05/221,498 |
Filed: |
January 28, 1972 |
Current U.S.
Class: |
102/505;
342/12 |
Current CPC
Class: |
F42B
12/70 (20130101) |
Current International
Class: |
F42B
12/70 (20060101); F42B 12/02 (20060101); F42b
013/56 () |
Field of
Search: |
;102/63,87,89,38,92.6,37.6,35.6,34.6 ;340/18B |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Stahl; Robert F.
Claims
What is claimed is:
1. A chaff bullet comprising:
a. a nose piece, a body and a rear section;
b. said rear section being operatively connected to the rear end of
said body;
c. a chaff element;
d. said chaff element being mounted within said body;
e. said chaff element comprising a pair of half shells and at least
one chaff packette mounted within said half shells;
f. each of said half shells includes a tapered end;
g. said nose piece including a cavity; and
h. each of the tapered ends of said half shells extends beyond the
front end of said body and into said cavity of said nose piece to
retain said nose piece in position.
2. The chaff bullet of claim 1 wherein:
a. said at least one chaff packette includes a plurality of
elongated chaff that is wrapped by a strip of thin plastic
wrapping.
3. The chaff bullet of claim 4 wherein:
a. a pair of half shells are positioned between said chaff and said
wrapping.
4. The chaff bullet of claim 1 wherein:
a. each of said half shells includes a flat end;
b. the flat ends of said half shells are positioned near the rear
end of said body; and
c. a piston is positioned adjacent said flat ends of said half
shells for driving said chaff element from said body.
5. The chaff bullet of claim 4 including:
a. a washer made of energy absorbing material positioned between
said piston and said rear section.
6. The chaff bullet of claim 6 wherein:
a. said rear sections include a tracer element containing a tracer
powder and an explosive charge; and
b. a metal section positioned between said tracer powder and said
explosive charge.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a chaff bullet, and more
particularly, to a chaff bullet that effectively releases the chaff
into the air in a well dispersed and undamaged condition.
2. Description of the Prior Art
One of the difficulties encountered with prior chaff bullets was
their inability to readily accomodate different sizes and numbers
of chaff. Another major difficulty was their inability to release
the chaff into a large area where the released chaff was well
dispersed and undamaged.
SUMMARY OF THE INVENTION
The present invention overcomes the above described disadvantages
of prior chaff bullets. Briefly, the present invention comprises a
chaff bullet having a nose piece, a body and a rear section. The
body encloses a chaff element which comprises a pair of half
shells, each tapered at one end, and a plurality of chaff packettes
positioned within the half shells. Each chaff packette includes
several thousand elongated chaff which are enclosed in a thin
wrapping of Mylar. When the chaff bullet is fired from a gun the
tracer power contained in the rear section burns slowly. After a
predetermined time the increasing heat from the burning tracer
powder causes ignition of an explosive in the body section which
forces out the chaff element. The spin of the bullet causes outward
release of the half shells and the chaff packettes. When the chaff
packettes enter the air stream the Mylar wrapping is unwrapped
which releases the chaff into the air in a well dispersed and
undamaged condition.
STATEMENT OF THE OBJECTS OF INVENTION
An object of the present invention is to provide an effective and
reliable chaff bullet.
Another object of the present invention is to provide a relatively
inexpensive chaff bullet.
A further object of the present invention is to provide a bullet
that can readily accomodate different sizes and numbers of
chaff.
A still further object of the present invention is to provide a
chaff bullet that releases the chaff into a large area where the
released chaff is well dispersed and undamaged.
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:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic drawing of the assembled chaff round of the
present invention;
FIG. 1A is a schematic drawing of the nose piece of the chaff
bullet of FIG. 1;
FIG. 1B is a schematic drawing of the body of the chaff bullet of
FIG. 1;
FIG. 1C is a schematic drawing of the rear section of the chaff
bullet of FIG. 1;
FIG. 1D is the side elevation of the pair of half shells of the
chaff bullet of FIG. 1;
FIG. 1E is an end view of the pair of half shells of FIG. 1D;
FIGS. 2A and 2B are schematic drawings of the chaff element of FIG.
1;
FIGS. 2C and 2D are schematic drawings of the chaff packette of the
chaff element of FIGS. 2A and 2B; and
FIGS. 3A through 3D are pictorial drawings showing the sequence of
operation of the chaff bullet of FIG. 1.
In FIG. 1 is shown a 20 mm chaff round 11 which consists of a shell
13 and a chaff bullet 15. The subject of the present invention is
the chaff bullet 15 and it is to be understood that the bullet may
be made in a variety of sizes and shapes and is not to be limited
in use with a 20 mm round. The chaff bullet 15 may be fired from
the shell 13 from a gun mounted on a flying aircraft. Normally,
there will be fired one chaff bullet for about five to ten live
bullets fired from the gun.
Chaff bullet 15 includes a nose piece 17, a body 19, and a rear
section 21. Nose piece 17 is illustrated in FIGS. 1 and 1A and has
an exterior configuration, as shown, and includes an elongated
cylindrical interior section 23 that includes threads 25 shown by
the dotted lines in FIG. 1A. The threads 25 are provided for
tooling which is used in the manufacturing process of the nose
piece. The rear section of nose piece 17 has an enlarged cavity 27
having a cylindrical section 29 and a conical section 31. The
cylindrical section 29 has a diameter a which is slightly smaller
than the diameter b of body 19, as shown in FIG. 1B. It should be
noted that the rear surface 33 of nose piece 17 abuts against the
forward surface 35 of body 19 when assembled, as illustrated in
FIG. 1. As will be hereinafter explained in greater detail, when
assembled the tapered ends 37 and 37' of half shells 39 and 39' are
in forced engagement with cylindrical surface 29.
Referring to FIGS. 1 and 1B, body 19 includes a circular groove 41
for receiving ring 43 and circular groove 45 for receiving circular
detent 47 of shell 13. The rear section of body 19 is provided with
female threads 49 for receiving male threads 50 of rear section 21
of FIG. 1C.
Rear section 21 of FIG. 1C includes a tracer element 51 that
comprises a cup having a steel cylindrical wall 53 and a steel
bottom section 55. The cup is filled with tracer powder 57 and is
closed by means of closure 59 which is made of a foil material such
as a heavy gauge aluminum foil. Rear section 21 also includes an
explosive charge 61 which may be bulls-eye pistol powder, for
example. Closure 62, which may be made of aluminum foil, seals the
explosive charge 61 in place and holds it against the forward
surface of bottom section 55. Tracer element 51 is retained in
position by means of circular lip 63 which prevents the tracer
element from being blown out by ignition of explosive charge
61.
Shell 13, which may be a 20 mm shell, for example, includes cap 65,
elongated section 67 and explosive powder 69. Upon being fired by
the gun, the powder within cap 65 ignites explosive charge 69 which
in turn ignites the powder in tracer element 57, rapidly
transmitting its heat through foil 59, and propels chaff bullet 15
in the forward direction.
In FIGS. 2A and 2B is illustrated the chaff element 71 used in the
chaff bullet 15 of FIG. 1. Chaff element 71 includes half shells 39
and 39', shown in FIGS. 1D, 1E, 2A, and 2B, which contain four
chaff packettes 73, as illustrated by the dotted lines of FIGS. 2A
and 2B. It is to be understood that more or less than four
packettes may be employed and one or more of them may be dummy
packettes. Also, depending upon the particular needs, the packettes
may be selected to have different lengths. In FIGS. 2C and 2D is
illustrated a single chaff packette 73. The chaff 75, comprising
approximately 20,000 pieces of very small metal covered glass rods,
are packed into half shells 77 and 77' of chaff packette 73. One
method for achieving this described chaff packette structure is to
draw 20,000 lengths of chaff 75 through a one-fourth inch soda
straw, then cut the straw to length and then make two slits
lengthwise in the straw to form half shells 77 and 77'. The chaff
filled half shells 77 and 77' are then wrapped by a thin Mylar
wrapping 79 having a width that is the same as the length of the
half shells. It has been found that a four-inch length of Mylar
film is very effective in that it provides an adequate time
interval before release at the chaff after the packette is
introduced into the air stream as will be hereinafter described in
detail.
Referring now to FIG. 1, the assembled chaff bullet includes chaff
element 71 that is inserted into body 19. The tapered ends 37, 37'
of half shells 39, 39' extend beyond the end of body 19. The
outside diameter of chaff element 71 is very slightly larger than
the inside diameter b of body 19 and is forced into body 19 and is
held in place by a snug fit. Also, the outside diameter of chaff
element 71 is substantially larger than the inside diameter a of
nose piece 17. Nose piece 17 is held in position by forcing it over
tapered ends 37, 37' until rear surface 33 of nose piece 17 abuts
against forward surface 35 of body 19. A metal piston 81, which is
preferably made of aluminum, abuts against the flat end of chaff
element 71 and a washer 83, preferably made of Teflon, abuts
against piston 81. Washer 83 functions to absorb the shock when the
bullet is initially fired from the gun. Rear section 21 is mounted
on the end of body 19 by means of threads 49 and 51 and shell 13 is
mounted on the rear part of body 19.
The following is a description of the operation of chaff round 11
when fired from a gun. The operation is initiated when the gun
hammer strikes cap 65 of shell 13. When this occurs the powder in
cap 65 ignites which in turn ignites explosive charge 69. The
ignition of explosive charge 69 simultaneously projects the chaff
bullet 15 down the gun barrel and ignites powder 57. While the
chaff bullet 15 travels down the barrel, the rifling of the gun
spins the bullet. This rotational spin of the chaff bullet is
important for its effective operation. As the powder 57 in tracer
element 51 burns, it causes a progressive temperature increase of
steel bottom section 55. When the temperature of bottom section 55
reaches about 1,000.degree. F, which occurs when the chaff bullet
15 is about 4500 feet from the gun, then explosive charge 61 is
ignited by this elevated temperature. It should also be noted that
bottom section 55 of tracer element 51 is sufficiently strong to
not blow out when explosive charge 61 ignites. When explosive
charge 61 ignites, the pressure generated thereby acts against
piston 81 which, being abutted against the flat surface of chaff
element 71, forces chaff element 71 out from body 19. This sequence
of operation is pictorially illustrated in FIG. 3B. As soon as the
chaff element 71 leaves the end of body 19 then the flat end of the
half shells 77 and 77' are free to move outward and will fly open
due to the centrifugal force caused by its rotation. This is
possible because the taper of tapered ends 37 and 37' permits the
shells to pivot about point "C" (see FIG. 1D) such that the flat
ends will rotate outwards due to the centrifugal force. When the
half shells 39, 39' fly outward then the chaff packettes 73 are
released and fly outward by centrifugal force. This sequence of
operation is pictorially illustrated in FIG. 3C. When the packettes
73 enter the wind stream then the wind unwinds the wrapping 79 from
the chaff 75. This releases the chaff 75 in an undamaged condition
into a large area of uniform dispersement and thereby provides an
effective radar decoy. This sequence of operation is pictorially
illustrated in FIG. 3D. It should be particularly noted that the
wrapping 79 protects the chaff 75 and allows sufficient time for
the chaff to slow down and travel outward before releasing half
shells 77, 77' and the chaff 75 contained therein. Normally, the
chaff bullet is traveling at about 1,000 feet per second when the
chaff element is expelled from the bullet body.
* * * * *