Note: Descriptions are shown in the official language in which they were submitted.
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Dct. No. 52-AR-230Ç
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CASED TELESCOPED AMMUNITIC)N
Field Of The Invention
.
This invention relates to cased telescoped am-
munition utilizing a "control tube" to provide an
initial forward displacement of the projectile from
5the case into the gun barrel prior to the subsequent
ig~ition of the main charge which propells the
projectile along the length of the gun barrel.
.
Background Of The Invention
Cased telescoped ammunition utilizing control
tubes are well known, and are shown, for example, in:
U.S. 4,938,145, issued July 3, 1990 to W.E. Martwick;
U.S. 4,907,510, issued March 13, 1990 to W.E.
Martwick, et al;
U.S. 4,846,069, issued July 11, 1989 to B.8. Tasson,
et al;
U.5. 4,803,927, issued Feb. 14, 1989 to W.J.
Washburn;
U.S. 4,782,758, issued Nov. 8, 1988 to W.J. washburn;
U.S. 4,691,638, issued Sept. 8, 1987 to D.A. Meyer,
et al; and
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Dct. No. 52--AR~2306
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U.S. 4,604,954, issued Aug. 12, 1986 to S.E. Clarke,
et al.
Cased telescoped ammunition not utilizing
control tubes are also well known, and are shown, ~or
example, in:
U.S. 3,009,394, issued Nov. 21, 1961 to E.A. Kamp, et
al.
The use of sabot projectiles having fin stabi-
lized long rod penetrators in cased telescoped ammu-
nition is also known, as shown in U.S. 4,846,069,
mentioned above. Other sabot projectiles are shown,
for example, in:
U.SO 4,881,466, issued Nov. 21, I989 to J.E.
McGinley;
U.S. 4,776,280, issued Oct. 11, 1988 to J. ~urri, et
al:
U.S. 3,714,900, issued Feb. 6, 1973 to F.K. Feldman
and
U.S. 3,496,869, issued Feb. 24, 1970 to W. Engel.
It will be noted that the sabots are not of -
full bore dimension at the forward end of the sabot
and penetrator ossembly, It will also be noted that
the use o~ spin stabilized penetrators in a sabot
projectile in a cased telescoped round is not shown.
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Dct. No. 52-A~-~306
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SUMMARY OF THE INVENTION
An object o this invention is to provide a
simplified cased telescoped round of ammunition uti-
lizing a control tube for (i) a full bore projectile
or (ii) an APDS sabot projectile (i.e., not a long
rod sabot projectile.)
Another object is to provide such a cased
telescoped round of minimalized length.
Yet another object is to provide such a cased
tele~coped round with a minimalized number of parts
to make up the assembly and wherein the control tube
i5 integral with the aft seal and itself retains the
projectile.
Still another object is to provide such a
cased telescoped round with an APDS sabot projectile
with minimalized potential balloting and minimalized
control tube launch strQke length.
A feature of this invention is a cased tele-
scoped round having a control tube which is integral
with the aft seal and itself retains the projectile
against loose forward movement.
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Dct. No. 52-AR-2306
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BRIEF DESCRIPTION OF THE DRAWING
These and other objects, features and
advantages o~ the invention will be apparent from the
following specification thereof taken in conjunction
with the accompanying drawing in which:
FIG. 1 is a longitudinal view in section of a
cased telescoped round with a controi tube and a full
bore projectile of the prior art;
FIG. 2 is a longitudinal view in section of a
cased telescoped round with a control tube and a full
bore projectile in a first embodiment of the inven-
tion; and
FIG. 3 is a longitudinal view in section of a
cased telescoped round with a control tube and an
APDS sabot projectile in a second embodiment of the
invention.
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Dct. No. 52-AR-2306
DETAI~ED DESCRIPTION OF THE INVENTION
Reference is first made to the prior art round
shown in FIG. 1. This round 10 is comprised of a
metal case 12 which is clipped to and between a front
seal 14 and an aft seal 16. A control tube 18 is
S fixed into a longitudinal bore 20 in the aft seal.
The tube 18 has an aft bore portion 22 in which is
fixed a primer 24, an intermediate flash passageway
26, and a forward bore portion 2~ in which is ~ixed a
booster charge 30. An annular aft main charge 32 and
an annular forward main charge 34 support these be-
tween a frangible retainer ~6 which is clipped into a
groove 38 in the base portion of a full bore pro-
jectile 40 (HEI, API or TP). The projectile has a
piston 42 extending aftwardly from its base portion
into the forward bore portion 28 of the control tube.
The projectile has a rotating band 44 to provide spin
stabilization. The front seal has a longitudinal
bore 46 therein which will pass the projectile and
which is closed by a frangible disc 48.
In operation, the primer 2g is percussed to provide
ignition gas to the booster charge 30 which generates
.
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Dct. No. 52-AR-2306
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an initial volume of hot combustion gas. The gas
acts against the aft surface of the piston 42 to moYe
the projectile forwardly, fracturing the retainer 36
and the disc 48, and into the gun barrel. When the
aft end of the piston exits the forward end of the
control tube, the hot combus~ion gas from the booster
vents rom the tube to ignite the forward and aft
main charges, which generate the main volume of
combustion gas to progressively fully seat the
projectile in the barrel~ engrave the ro~ating band,
and send the projectile along the lenqth of the gun
barrel and out the muzzle.
It will be appreciated that (i) the length of
such a round must accomodate the length of the pis-
ton, (ii) there are many parts to assemble in fabri-
cating thc round, and (iii) the piston displaces the
center of gravity of the projectile undesirably
aftwards, induces parasitic aerodynamics, and makes
no useful contribution of fragme`nts when the HEI
pro~ectile impacts the target.
A much shorter and simpler round is shown in
FI&. 2 as a first embodiment of the present inven-
tion. This round lO0 is comprised of a case 112
(here shown as metal, but which may be nonmetallic)
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Dct. No. 52-AR-2306
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which is clipped to and between a front seal 114 and
an aft seal 116 which also serves as a full caliber
control tube and a projectile retention device.
Alternatively, the case 112 may be integral with the
aft seal 116. The main charge 118 is a single tube
having a longitudinal bore having a forward portion
with a diameter to accommodate the diameter of the
rotating band 120 on the projectile 122, and an aft
portion with a diameter to accommodate the diameter
of the control tube portion 116A of the aft seal 116.
The forward-most margin of the control tube portion
has an annular crimp 124 which fits into an annular
groove 126 in the projectile 122 aft of the rotating
band. The aft seal 116 also has a cup 116B formed
therein which receives a primer 128, and a flash
passageway 130 which leads into the interior of the
control tube portion which receives the booster
charges 132. The annular crimp 124 is formed after
the booster and the projectile have been inserted
into the control tube portion in the same manner that
the neck of a conventional cartridge case is crimped
onto a projectile. ~he ~EI projectile will include a
fuze, which may be of the type shown in U.S.
4,242,963, is~ued Jan. 6, 1981 to R.T. Ziemba. The
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Dct. No. 52-AR-2306
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case joins the seals with snap-in features, not
shown, which may be of the type shown in U.S.
4,591,63a, m~ntioned previously. Thus, the raund is
made up o~ seven parts: projectile, primer, booster
charge, main charge, aft seal, forward seal and case.
Another much shorter and simpler round is
shown in FIG. 3 as a second embodiment of the present
invention. The round shown here is an APDS configu-
ration with a modification of the sabot projectile
shown in U.S. 4,881,466, issued Nov. 2, 1989 to J.~.
McGinley. This round 200 is comprised of a metal
case 212 which is clipped to and between a front seal
214 and an aft seal 216 which also serves as a full
caliber control tube and a projectile retention de-
vice. The main charge 218 is a single tube having a
longitudinal bore having a forward portion with a di-
ameter to accommodate the rotating band 220 in the
sabot foresection 222, and an aft portion with a
diameter to accommodate the diameter of the control
~ tube portion 216A of the aft seal 216. The forward-
most margin of the control tube portion has an annu-
lar cri~p 224 which fits into an annular groove 226
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Dct. No. 52-AR-2306
_g_
in the sabot foresection 22~ aft of the rotating
band. The aft seal 216 also has a cup 216B formed
therein which receives a primer 228 formed therein
which receives a primer 228 and a flash passageway
230 which leads into the interior of the control tube
portion which receives the booster charge 232. The
sabot assembly includes a pusher 234. The sabot
foresection 236 also provides a bore-rider and an
integral closed front 238. The,subcaliber penetrator
240 is surmounted with a windscreen 242.
The blunt-nose sabot projectile provided by
the bore-rider provides two major improvements over
the conventional sabot projectile: (i) the penetra-
tor is much better supported in the barrel bore,
thereby reducing balloting of the projectile and re-
sultant dispersion, and (ii) the barrel bore is
sealed sooner in the launch stroke which enables much
greater flexibility in the design of the control tube
launch and sequencing of the main charge ignition,
i.e., the conventional problem of obturating the bar-
rel prior to main charge ignition is eliminated.
~oc~ation of the rotating band along the sabot is also
Dct. N~. 52-AR-2306
--10--
flexible from the point of view of launch dynamics
and may be moved forward on the projectile to allo~
the full-bore control tube to extend further forward.
This is true for conventional and saboted pro-
jectiles. Obviously, constraints on sabot strength
and transmission of rotational loads for spin-up must
also be considered in band location.
