U.S. patent application number 10/182246 was filed with the patent office on 2003-05-15 for sabot stripping.
Invention is credited to O'Dwyer, James Michael.
Application Number | 20030089221 10/182246 |
Document ID | / |
Family ID | 3819632 |
Filed Date | 2003-05-15 |
United States Patent
Application |
20030089221 |
Kind Code |
A1 |
O'Dwyer, James Michael |
May 15, 2003 |
Sabot stripping
Abstract
Barrel assembly (10) includes an array of individual barrels
(11) with each barrel (11) including a sabot stripping structure
(23) and a sabot receiver (28) arranged to collect and prevent
sabots (14) from exiting muzzle (20) of barrel (11). Each barrel
(11) incoporates a multiplicity of sabotted projectiles (12)
stacked axially within barrel (11) and a multiplicity of interposed
corresponding propellent charges (16). Sabotted projectiles (12)
each comprise projectile (13) and an associated sabot (14)
detachably engaged with projectile (13). Detonation of a leading
propellant charge (16) urges following sabotted projectiles (12)
into sealing engagement with respective barrels (11).
Inventors: |
O'Dwyer, James Michael;
(Brisbane, AU) |
Correspondence
Address: |
FINNEGAN, HENDERSON, FARABOW, GARRETT &
DUNNER LLP
1300 I STREET, NW
WASHINGTON
DC
20006
US
|
Family ID: |
3819632 |
Appl. No.: |
10/182246 |
Filed: |
October 18, 2002 |
PCT Filed: |
February 9, 2001 |
PCT NO: |
PCT/AU01/00087 |
Current U.S.
Class: |
89/14.6 |
Current CPC
Class: |
F41A 21/46 20130101;
F42B 5/035 20130101 |
Class at
Publication: |
89/14.6 |
International
Class: |
F41A 021/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 9, 2000 |
AU |
PQ5313 |
Claims
1. A barrel assembly incorporating a multiplicity of sabotted
projectiles stacked axially within the barrel assembly and a
multiplicity of corresponding propellant charges disposed
therebetween wherein the barrel assembly includes a barrel having a
muzzle and wherein said barrel includes a sabot stripping structure
and a sabot receiver arranged whereby sabots are prevented from
exiting the muzzle of the barrel and wherein the multiplicity of
sabotted projectiles comprise a multiplicity of projectiles and a
multiplicity of associated sabots wherein the associated sabots
detachably engage the projectiles whereby detonation of a leading
propellant urges subsequent sabotted projectiles into sealing
engagement with the barrel.
2. A barrel assembly according to claim 1 wherein the multiplicity
of projectiles have bullet shaped head portion about which the
sabot is disposed and a tail portion that extends rearwardly into
abutting relationship with the leading end of the next adjacent
trailing projectile whereby the stacked column of sabotted
projectiles are positively located in their operative positions in
the barrel.
3. A barrel assembly according to claim 1 wherein the sabot
detachably engages the projectile whereby it is secured it against
forward movement relative to the projectile.
4. A barrel assembly according to claim 3 wherein the sabot is
detachably secured to the projectile by a detent for engaging a
corresponding recess on the projectile.
5. A barrel assembly according to claim 3 wherein the projectile
incorporates a detent for engaging a corresponding recess on the
sabot.
6. A barrel assembly according to claim 3 wherein the sabot
includes complementary shallow inwardly directed annular ribs on
the inner face of the sabot for engagement with shallow outer
annular recesses in the projectile.
7. A barrel assembly according to claim 3 wherein the sabot
includes an annular concavity in the inner face of the sabot for
engagement with a complementary convex outer annular portion of the
projectile.
8. A barrel assembly according to claim 3 wherein the sabot
detachably engage the projectile through an interference fit.
9. A barrel assembly according to claim 8 wherein the interference
fit is a tapered interference fit.
10. A barrel assembly according to claim 1 wherein the associated
sabots comprise a pair of complementary continuous or segmented
annular portions that engage through opposed tapered land portions
whereby the outer annular portion is urged to expand radially upon
commencement of movement of the inner annular portion therethrough
to sealably engage the barrel wherein the inner annular portion is
urged to move through the outer annular portion by the detonation
of the propellant charge in front of the sabotted projectile in the
array of axially stacked projectiles.
11. A barrel assembly according to claim 10 wherein a transversely
extending flange is provided on one annular portion to limit the
relative longitudinal movement of the inner portion through the
outer portion.
12. A barrel assembly according to claim 11 the flange is a radial
outwardly extending flange formed on the trailing end of the inner
annular portion.
13. A barrel assembly according to claim 1 wherein the sabot
stripping structure includes an inner sleeve portion at or adjacent
the muzzle and disposed concentric with the barrel and through
which the projectiles pass and about which the sabots pass.
14. A barrel assembly according to claim 13 wherein the inner
sleeve is suitably tapered at its stripping end to urge the sabot
away from the projectile into an annular barrel portion between the
sleeve and the muzzle of the barrel.
15. A barrel assembly according to claim 13 wherein the inner
sleeve portion is supported by webs extending between the inner
sleeve and the barrel.
16. A barrel assembly according to claim 1 wherein the barrel
flares outwardly at the muzzle.
17. A barrel assembly according to claim 1 wherein the stripped
sabot is retained in an annular storage portion at the muzzle end
of the barrel.
18. A barrel having a muzzle and wherein said barrel includes a
sabot stripping structure and a sabot receiver arranged whereby
sabots are prevented from exiting the muzzle of the barrel.
19. A barrel according to claim 18 wherein the sabot stripping
structure includes an inner sleeve portion at or adjacent the
muzzle and disposed concentric with the barrel and through which
projectiles pass and about which sabots pass.
20. A barrel according to claim 19 wherein the inner sleeve is
suitably tapered at its stripping end to urge the sabot away from
the projectile into an annular barrel portion between the sleeve
and the muzzle of the barrel.
21. A barrel according to claim 19 wherein the inner sleeve portion
is supported by webs extending between the inner sleeve and the
barrel.
22. A barrel according to claim 18 wherein the barrel flares
outwardly at the muzzle.
23. A barrel according to claim 18 wherein the barrel includes an
retainer whereby the stripped sabot is retained in an annular
storage portion at the muzzle end of the barrel.
24. A sabotted projectile for stacking axially within a barrel
assembly comprising a projectile and a sabot wherein the sabot
detachably engages the projectile wherein detonation of a leading
propellant in an axially stacked array urges subsequent sabotted
projectiles into sealing engagement with the barrel.
25. A sabotted projectile according to claim 24 wherein the
projectile has a bullet shaped head portion about which the sabot
is disposed and a tail portion that extends rearwardly into
abutting relationship with the leading end of the next adjacent
trailing projectile whereby a stacked column of sabotted
projectiles are positively located in their operative positions in
the barrel.
26. A sabotted projectile according to claim 24 wherein the sabot
detachably engages the projectile whereby it is secured it against
forward movement relative to the projectile.
27. A sabotted projectile according to claim 26 wherein the sabot
is detachably secured to the projectile by a detent for engaging a
corresponding recess on the projectile.
28. A sabotted projectile according to claim 26 wherein the
projectile incorporates a detent for engaging a corresponding
recess on the sabot.
29. A sabotted projectile according to claim 26 wherein the sabot
includes complementary shallow inwardly directed annular ribs on
the inner face of the sabot for engagement with shallow outer
annular recesses in the projectile.
30. A sabotted projectile according to claim 26 wherein the sabot
includes an annular concavity in the inner face of the sabot for
engagement with a complementary convex outer annular portion of the
projectile.
31. A sabotted projectile according to claim 26 wherein the sabot
detachably engages the projectile through an interference fit.
32. A sabotted projectile according to claim 31 wherein the
interference fit is a tapered interference fit.
33. A sabotted projectile according to claim 24 wherein the
associated sabots comprise a pair of complementary continuous or
segmented annular portions that engage through opposed tapered land
portions whereby the outer annular portion is urged to expand
radially upon commencement of movement of the inner annular portion
therethrough to sealably engage the barrel wherein the inner
annular portion is urged to move through the outer annular portion
by the detonation of the propellant charge in front of the sabotted
projectile in the array of axially stacked projectiles.
34. A sabotted projectile according to claim 33 wherein a
transversely extending flange is provided on one annular portion to
limit the relative longitudinal movement of the inner portion
through the outer portion.
35. A sabotted projectile according to claim 34 the flange is a
radial outwardly extending flange formed on the trailing end of the
inner annular portion.
Description
[0001] The present invention relates to munitions and firearms, in
particular the present invention relates to a sabotted round, to a
barrel assembly for launching a sabotted round and to such a barrel
assembly incorporating a multiplicity of sabotted projectiles
stacked axially within the barrel assembly.
[0002] Sabotted projectiles are employed in applications requiring
projectiles to have high kinetic energies, such as in penetrating
armour plate on ships and tanks, and for long range applications. A
sabotted projectile generally incorporates a sub-calibre projectile
that is adapted by a relatively lightweight sabot to provide a gas
seal with the bore of the barrel. The sabot permits the propellant
charge to exert the propulsive force over a larger area and thus
the sub-calibre projectile and relatively lightweight sabot
achieves a greater in-barrel velocity than a full diameter
projectile.
[0003] The sabot is separated from the sub-calibre projectile,
typically after it exits the muzzle of the barrel and in one
configuration can be adapted to disintegrate after it emerges from
the muzzle of the barrel. Other sabot configurations employ
different systems for separating the sabot from the sub-calibre
projectile. The differing centrifugal forces generated in the sabot
and sub-calibre projectile by a rifled barrel have been employed in
sabot designs to separate the sabot from the sub-calibre
projectile. The aerodynamic drag on the sabot relative to that on
the sub-calibre projectile in other configurations may be used to
separate the sabot from the sub-calibre projectile.
[0004] Barrel assemblies having a plurality of projectiles stacked
axially within a barrel together with discrete selectively
ignitable propellant charges for propelling the projectiles
sequentially through the muzzle of the barrel allow the projectile
to be fire at extremely high rates. Firing sabotted rounds at such
high rates increases the likelihood of a projectile striking the
sabot from a previously fired round and being rendered ineffective.
We have now found a configuration that minimises the likelihood of
a projectile striking the sabot from a previously fired round.
[0005] Accordingly, in one aspect the present invention provides a
barrel assembly incorporating a multiplicity of sabotted
projectiles stacked axially within the barrel assembly and a
multiplicity of corresponding propellant charges disposed
therebetween wherein the barrel assembly includes a barrel having a
muzzle and wherein said barrel includes a sabot stripping structure
and a sabot receiver arranged whereby sabots are prevented from
exiting the muzzle of the barrel and wherein the multiplicity of
sabotted projectiles comprise a multiplicity of projectiles and a
multiplicity of associated sabots wherein the associated sabots
detachably engage the projectiles whereby detonation of a leading
propellant urges subsequent sabotted projectiles into sealing
engagement with the barrel.
[0006] In a second aspect the present invention provides a barrel
having a muzzle and wherein said barrel includes a sabot stripping
structure and a sabot receiver arranged whereby sabots are
prevented from exiting the muzzle of the barrel.
[0007] In a third aspect the present invention provides a sabotted
projectile for stacking axially within a barrel assembly comprising
a projectile and a sabot wherein the sabot detachably engages the
projectile wherein detonation of a leading propellant in an axially
stacked array urges subsequent sabotted projectiles into sealing
engagement with the barrel.
[0008] The present invention may utilise barrel assemblies capable
of firing a controlled rapid fire sequence of projectiles and being
of the general type described and/or illustrated in our earlier
International Patent Applications, including PCT/AU94/00124 and
PCT/AU96/00459. However other barrel assemblies incorporating
discrete propellant charges for propelling respective sabotted
projectiles stacked axially within the barrel assembly may be used
in the present invention.
[0009] The projectile may be round, conventionally shaped or
dart-like and the fins thereof may be offset to generate a
stabilising spin as the dart is propelled from a barrel that may be
a smooth-bored barrel.
[0010] Each projectile may include a projectile head and tail
portion for at least partly defining a propellant space. The tail
portion may include a spacer assembly that extends rearwardly from
the projectile head and abuts an adjacent projectile assembly.
[0011] The spacer assembly may extend through the propellant space
and the projectile head whereby compressive loads are transmitted
directly through abutting adjacent spacer assemblies. In such
configurations, the spacer assembly may add support to the
extension means that may be a thin cylindrical rear portion of the
projectile head. Furthermore the extension means may form an
operative sealing contact with the bore of the shell to prevent
burn leakage past the projectile head.
[0012] The spacer assembly may include a rigid collar that extends
outwardly to engage a thin cylindrical rear portion of the
malleable projectile head inoperative sealing contact with the bore
of the shell such that axially compressive loads are transmitted
directly between spacer assemblies thereby avoiding deformation of
the malleable projectile head.
[0013] It is preferred that each projectile has a bullet shaped
head portion about which the sabot is positioned and a tail portion
which extends rearwardly into abutting relationship with the
leading end of the next adjacent trailing projectile whereby the
stacked column of rounds are positively located in their operative
positions in the barrel. This configuration allows for high volumes
of propellant charges to be employed for each projectile thereby
providing high kinetic energy to the projectile.
[0014] Alternatively, the projectile charge may be form as a solid
block to operatively space the projectiles in the shell or the
propellant charge may be encased in metal or other rigid case which
may include an embedded primer having external contact means
adapted for contacting an pre-positioned electrical contact
associated with the shell. For example the primer could be provided
with a sprung contact which may be retracted to enable insertion of
the cased charge into the shell and to spring out into an aperture
upon alignment with that aperture for operative contact with its
mating shell contact. If desired the shell may be consumable or may
chemically assist the propellant burn.
[0015] The sabot may be in the form of complementary wedging
surfaces disposed on the projectile head respectively whereby the
projectile head is urged into engagement with the bore of the
barrel in response to relative axial compression between the spacer
means and the projectile head. In such arrangement the projectile
head and spacer assembly may be loaded into the barrel and there
after an axial displacement is caused to ensure good sealing
between the projectile head and barrel. Suitably the extension
means is urged into engagement with the bore of the barrel.
[0016] The barrel may be non-metallic and the bore of the barrel
may include recesses that may fully or partly accommodate the
ignition means. In this configuration the barrel houses electrical
conductors which facilitate electrical communication between the
control means and ignition means. This configuration may be
utilised for disposable barrel assemblies that have a limited
firing life and the ignition means and control wire or wires
therefor can be integrally manufactured with the barrel.
[0017] A cartridge may alternatively include ignition apertures in
the barrel and the ignition means may be disposed outside the
barrel and adjacent the apertures. The barrel may be surrounded by
a non-metallic outer barrel that may form the sleeve which may
include recesses adapted to accommodate the ignition means. The
outer barrel may also house electrical conductors that facilitate
electrical communication between the control means and ignition
means. The outer barrel may be formed as a laminated plastics shell
which may include a printed circuit laminate for the ignition
means.
[0018] The cartridge may have adjacent projectiles that are
separated from one another and maintained in spaced apart
relationship by locating means separate from the projectiles, and
each projectile may include an expandable sealing means for forming
an operative seal with the bore of the barrel. The locating means
may be the propellant charge between adjacent projectiles and the
sealing means suitably includes a skirt portion on each projectile
which expands outwardly when subject to an in-shell load. The
in-shell load may be applied during installation of the projectiles
or after loading such as by tamping to consolidate the column of
projectiles and propellant charges or may result from the firing of
an outer projectile and particularly the adjacent outer
projectile.
[0019] The projectiles may be adapted for seating and/or location
within circumferential grooves or by annular ribs in the bore or in
rifling grooves in the bore and may include a metal jacket encasing
at least the outer end portion of the projectile. The projectile
may be provided with contractible peripheral locating rings which
extend outwardly into annular grooves in the shell and which
retract into the projectile upon firing to permit its free passage
through the barrel.
[0020] The electrical ignition for sequentially igniting the
propellant charges of a barrel assembly may preferably include the
steps of igniting the leading propellant charge by sending an
ignition signal through the stacked projectiles, and causing
ignition of the leading propellant charge to arm the next
propellant charge for actuation by the next ignition signal.
[0021] Ignition of the propellant may be achieved electrically or
ignition may utilise conventional firing pin type methods such as
by using a centre-fire primer igniting the outermost projectile and
controlled consequent ignition causing sequential ignition of the
propellant charge of subsequent rounds. This may be achieved by
controlled rearward leakage of combustion gases or controlled
burning of fuse columns extending through the projectiles.
[0022] In another form the ignition is electronically controlled
with respective propellant charges being associated with primers
which are triggered by distinctive ignition signals. For example
the primers in the stacked propellant charges may be sequenced for
increasing pulse width ignition requirements whereby electronic
controls may selectively send ignition pulses of increasing pulse
widths to ignite the propellant charges sequentially in a selected
time order. Preferably however the propellant charges are ignited
by a set pulse width signal and burning of the leading propellant
charge arms the next propellant charge for actuation by the next
emitted pulse.
[0023] Suitably in such embodiments all propellant charges inwardly
from the end of a loaded barrel are disarmed by the insertion of
respective insulating fuses disposed between insertion of
respective insulating fuses disposed between normally closed
electrical contacts, the fuses being set to burn to enable the
contacts to close upon transmission of a suitable triggering signal
and each insulating fuse being open to a respective leading
propellant charge for ignition thereby.
[0024] Any convenient trigger may be used in the present invention.
Conventional trigger mechanisms may be employed. In such
conventional trigger mechanisms the single firing event may be a
single squeeze or depression of the trigger for the predetermined
number of projectiles to be fired. There is no requirement to
maintain the trigger in a depressed state for the predetermined
number of projectiles to be fired as would be the case with an
automatic weapon such as a machine gun in automatic mode. Other
trigger mechanisms may be employed provided that a single firing
event initiated directly by the user, or remotely, activates the
trigger and fires the predetermined number of projectiles.
[0025] The sabot associated with the projectile is desirably
configured to prevent forward movement relative to the projectile
whereby the sabot is accelerated integrally with the projectile
through the barrel towards the muzzle. Preferably the sabot
detachably engages the projectile whereby it is secured it against
forward movement relative to the projectile. The sabot may be
detachably secured to the projectile by a detent for engaging the
projectile, for example into a corresponding recess. Alternatively
the projectile may incorporate a detent for engaging the sabot, for
example into a corresponding recess on the sabot. Preferably the
detachable engagement of the sabot to the projectile does not
inhibit its relative rearward movement along the projectile for
stripping purposes whereby the projectile is not slowed
significantly as the sabot is stripped from the projectile.
[0026] In one embodiment complementary shallow inwardly directed
annular ribs on the inner face of the sabot are located in shallow
outer annular recesses in the projectile and which are disengaged
by the stripping arrangement. Alternatively an annular concavity in
the inner face of the sabot may be located about a complementary
convex outer annular portion of the projectile which is disengaged
by the stripping arrangement. In a further embodiment an
interference fit, and preferably a tapered interference fit,
between the projectile and the sabot may provide detachable
engagement between the sabot and the projectile and which may be
dislodged upon forward movement of the projectile relative to the
sabot, such as that which occurs by the stripping arrangement.
[0027] In a preferred embodiment each sabot comprises a pair of
complementary continuous or segmented annular portions that engage
through opposed tapered land portions whereby the outer annular
portion is urged to expand radially upon commencement of movement
of the inner annular portion therethrough to sealably engage the
barrel. The inner annular portion is urged to move through the
outer annular portion by the detonation of the propellant charge in
front of the sabotted projectile in the array of axially stacked
projectiles. A transversely extending flange may be provided on one
annular portion to limit the relative longitudinal movement of the
inner portion through the outer portion. In one embodiment,
preferably this flange is a radial outwardly extending flange
formed on the trailing end of the inner annular portion.
[0028] The barrel assembly includes a barrel having a said barrel
includes a sabot stripping structure and a sabot receiver arranged
whereby sabots are prevented from exiting the muzzle of the
barrel.
[0029] Preferably the sabot stripping structure includes an inner
sleeve portion at or adjacent the muzzle and disposed concentric
with the barrel and through which the projectiles may pass and
about which the sabots pass. The sleeve may be suitably tapered at
its stripping end to urge the sabot away from the projectile into
an annular barrel portion between the sleeve and the muzzle of the
barrel.
[0030] In a preferred form the barrel flares outwardly at the
muzzle adjacent the stripping end of the sleeve to accommodate the
sabots stripped from the sabotted projectiles substantially without
radial compression of the stripped sabots. The inner sleeve portion
may be supported by webs extending between the sleeve and the
flared section of the barrel and between which stripped segments of
the sabot may pass.
[0031] The stripped sabot may pass through the annular barrel
portion adjacent the sleeve. Preferably, the stripped sabot is
retained in an annular storage portion of the muzzle end of the
barrel so as to prevent its possible interference with a following
one of a group of projectiles fired in rapid succession. The
stripped sabot may be allowed to exit the barrel through a lateral
aperture adjacent the muzzle.
[0032] The braking of the stripped sabots in the barrel will
provide a reaction that will assist in reducing the recoil action
of a barrel assembly. This reaction may also be achieved by forcing
a radial compression of the sabot during transit through the
annular passage.
[0033] In order that this invention may be more readily understood
and put into practical effect, reference will now be made to the
accompanying drawing wherein:
[0034] FIGURE 1 is a diagrammatic sectional view of a typical
multi-barrel firearm of the invention illustrated in diagrammatic
cross-sectional form for explanatory purposes.
[0035] The multi-barrel firearm 10 comprises a cluster of barrels
11 each supporting a plurality of rounds 12 in axially stacked
relationship in the respective barrels 11.
[0036] Each round comprises a projectile head 13 supported within
the respective barrel by a sabot assembly 14. A tail portion 15
extends rearwardly into abutting relationship with the nose of the
following projectile 12. For this purpose the rear end of the
trailing stem 15 is provided with a recess which snugly
accommodates the leading end of the projectile 13.
[0037] Propellant 16 extends about the trailing stems 15 and when
ignited, either electrically or otherwise, acts against the sabots
14 and any laterally extending faces of the respective projectiles
to propel them together with their sabots 14 through the barrel
towards the muzzle end 20 of the barrel 10.
[0038] Each barrel 12 flares outwardly at 21 towards the muzzle
from a point adjacent the inner end 22 of a concentric stripping
sleeve 23 supported within the respective flared end sections 24 by
end walls 25.
[0039] The bore diameter of the sleeves 23 are substantially the
same as the external diameter of the projectile heads 13 so that
projectile heads may pass directly therethrough and exit the barrel
assembly 10 at high velocity.
[0040] The sleeves 23 taper toward their trailing ends to present a
relatively fine annular end to approaching rounds so as to engage
between the sabot 14 and the projectile head 13 to strip the sabot
14 from the projectile head 13 as it passes into the sleeve 23. The
sabots 14 are diverted about the sleeves 23 by radial expansion
thereof or in segments and collect in the annular passage 28 which
extends about the sleeve 23.
[0041] This action causes a change of direction of the sabot
portions about the sleeve 23 so that the action will slow and
subsequently stop the sabots 14 by impact with the end wall 25 or
another sabot already located within the passage 28.
[0042] This action may be accompanied by a sharp deceleration just
prior to impact as gasses are compressed between the leading end of
the sabot and the end wall 25. The resultant staged deceleration of
the sabots 14 will assist in reducing the recoil action resulting
from ignition of the respective propellant charges.
[0043] Each sabot 14 has an inner annular part 30 engaged on the
projectile head 13 through complementary engaged serrations 29 and
an associated outer annular part 31 which mates with the inner
annular part 30 along a forwardly tapered face 33 such that
acceleration of the sabot through the barrel 11 will tend to force
the outer part 31 rearwardly along the inner part 30, accompanied
by a consequent radial expansion urging the sabot 14 into effective
sealing relationship with the barrel 11.
[0044] A radial flange 32 extends from the back face of the inner
part 30 to provide a limit for rearward movement of the outer part
32 and/or a reaction face 35 substantially spanning the barrel 11
and against which the products of combustion of the propellant can
react.
[0045] From the above it will be seen that the beneficial effects
of sabots enabling the use of larger quantities of propellant may
be achieved without sabot debris causing local effect and without
air borne sabot debris providing collision obstacles for
subsequently fired rounds.
[0046] It will of course be realised that the above has been given
only by way of illustrative example of the invention and that all
such modifications and variations thereto as would be apparent to
persons skilled in the art are deemed to fall within the broad
scope and ambit of the invention as is herein set forth.
* * * * *