U.S. patent application number 09/848151 was filed with the patent office on 2001-09-13 for blank cartridge for self loading guns.
Invention is credited to Saxby, Michael Ernest.
Application Number | 20010020428 09/848151 |
Document ID | / |
Family ID | 10838788 |
Filed Date | 2001-09-13 |
United States Patent
Application |
20010020428 |
Kind Code |
A1 |
Saxby, Michael Ernest |
September 13, 2001 |
Blank cartridge for self loading guns
Abstract
The invention provides a blank pyrotechnic cartridge comprising
a cartridge casing having a bullet-like projection extending
forwardly therefrom, the bullet-like projection being retractable
through an opening in the casing when the cartridge is fired, the
cartridge being axially expandable in a rearwards direction in use
to move the breechblock of a firearm to recycle the firearm. Also
provided is a method of feeding blank ammunition into the barrel of
a gun comprising the step of loading the gun with a blank
cartridge, the blank cartridge comprising a cartridge casing having
a bullet-like projection extending forwardly therefrom, the
bullet-like projection being retractable through an opening in the
casing when the cartridge is fired, the cartridge being axially
expandable in a rearwards direction in use to move a breechblock of
the gun to recycle the gun.
Inventors: |
Saxby, Michael Ernest;
(Bexhill-on-Sea, GB) |
Correspondence
Address: |
LAHIVE & COCKFIELD
28 STATE STREET
BOSTON
MA
02109
US
|
Family ID: |
10838788 |
Appl. No.: |
09/848151 |
Filed: |
May 3, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09848151 |
May 3, 2001 |
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09220640 |
Dec 24, 1998 |
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Current U.S.
Class: |
102/444 |
Current CPC
Class: |
F42B 8/04 20130101 |
Class at
Publication: |
102/444 |
International
Class: |
F42B 008/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 14, 1998 |
GB |
9819928.4 |
Claims
What is claimed is:
1. A blank pyrotechnic cartridge comprising a cartridge casing
having a bullet-like projection extending forwardly therefrom, the
bullet-like projection being retractable through an opening in the
casing when the cartridge is fired, the cartridge being axially
expandable in a rearwards direction in use to move the breechblock
of a firearm to recycle the firearm.
2. A blank cartridge according to claim 1 wherein sealing means are
provided for preventing propellant gases from escaping through the
opening upon firing.
3. A blank cartridge according to claim 1 wherein the expandable
cartridge casing comprises a piston portion slidably received
within a sleeve portion.
4. A blank cartridge according to claim 3 wherein the cartridge
casing has a nose portion and the sleeve portion extends rearwardly
of the nose portion.
5. A blank cartridge according to claim 4 wherein the bullet-like
projection is connected to or formed integrally with the piston
portion.
6. A blank cartridge according to claim 4 wherein the piston has a
hollow rear portion from which the bullet-like projection extends
forwardly.
7. A blank cartridge according to claim 6 wherein the hollow rear
portion contains a pyrotechnic composition.
8. A blank cartridge according to claim 7 wherein the hollow rear
portion defines a first expansion chamber, and a second expansion
chamber is defined by inner surfaces of the nose portion and
sleeve, and a leading surface of the hollow rear portion, one or
more gas channels being provided between the first and second
expansion chambers.
9. A blank cartridge including a sleeve extending rearwardly from a
nose portion, and a piston slidably disposed within the sleeve; the
piston having at its forward end a bullet-like spigot slidably
received in a channel through the nose portion and extending
forwardly of the nose portion, the piston having at its rearward
end a chamber containing a pyrotechnic composition; an expansion
chamber being provided within the sleeve between the piston and the
nose portion, one or more gas channels being provided between the
pyrotechnic composition in the piston and the expansion chamber;
whereupon after ignition of the pyrotechnic composition, expanding
gas passing through the or each gas channel into the expansion
chamber moves the piston rearwardly in the sleeve, the rearward
movement of the piston causing the gun to recycle and the
bullet-like spigot to retract into the nose portion.
10. A blank cartridge according to claim 9 wherein the piston is
hollow and one or more gas channels are provided between the hollow
interior of the piston and the expansion chamber.
11. A blank cartridge according to claim 9 wherein the expansion
chamber is defined by a radially inner surface of the sleeve, a
generally axially facing surface of the piston and a generally
axially facing surface of the nose portion.
12. A blank cartridge according to claim 9 wherein the expansion
chamber is of generally annular configuration, surrounding the
axially inner end of the bullet-like spigot.
13. A blank cartridge including a sleeve extending rearwardly from
a nose portion, and a hollow piston slidably disposed within the
sleeve; the piston having a bullet-like spigot slidably received in
a channel through the nose portion and extending forwardly of the
nose portion; an expansion chamber being provided within the sleeve
between the hollow piston and the nose portion, one or more gas
channels being provided between the hollow interior of the piston
and the expansion chamber; whereupon after ignition, expanding gas
passing into the expansion chamber moves the piston rearwardly in
the sleeve, the rearward movement of the piston causing the gun to
recycle, and the bullet-like spigot to be retracted into the nose
portion.
14. A blank cartridge according to claim 1 3 wherein the expansion
chamber is of generally annular configuration, surrounding the
axially inner end of the bullet-like spigot.
15. A blank cartridge according to of claim 13 wherein the
bullet-like spigot is sealed within the channel through the nose
portion by sealing means sited in a circumferential recess around
the spigot.
16. A blank cartridge according to claim 15 wherein the sealing
means takes the form of a circumferential sealing means, for
example, an `O`-ring.
17. A blank cartridge according to claim 13 wherein the bullet-like
spigot is of a length such that after ignition, the greater part of
its length is withdrawn into the nose portion.
18. A blank cartridge comprising a cartridge casing having a
bullet-like projection extending forwardly therefrom, the
bullet-like projection being retractable through an opening in the
casing when the cartridge is fired, sealing means being provided
for preventing propellant gases from escaping through the opening
upon firing; the cartridge being axially expandable in a rearwards
direction in use to move the breechblock of a firearm to recycle
the firearm.
19. A blank cartridge according to claim 18 which is a pyrotechnic
cartridge.
20. A combination of a firearm and a blank cartridge, the firearm
having a firing chamber in which the blank cartridge is received,
the cartridge being expandable upon ignition such that a portion
thereof is propelled rearwardly against a breechblock at one end of
the firing chamber to recycle the firearm, the cartridge having a
bullet like projection extending forwardly therefrom, the
bullet-like projection being retracted into the cartridge upon
ignition; wherein the length of the cartridge after complete
expansion thereof is limited such that the cartridge can be ejected
from the chamber.
21. A method of feeding blank ammunition into the barrel of a gun
comprising the step of loading the gun with a blank cartridge, the
blank cartridge comprising a cartridge casing having a bullet-like
projection extending forwardly therefrom, the bullet-like
projection being retractable through an opening in the casing when
the cartridge is fired, the cartridge being axially expandable in a
rearwards direction in use to move a breechblock of the gun to
recycle the gun.
22. A method of feeding blank ammunition into the barrel of a gun
according to claim 21 wherein the bullet-like projection extends
forwardly of the nose portion to an extent equivalent to a
cartridge carrying live ammunition.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to blank cartridges,
particularly those used for training in conjunction with simulators
and war games. More especially, the invention relates to a blank
cartridge that will cycle most known types of self loading small
calibre guns without the use of external adapters or the release of
toxic gases and debris.
[0002] The object of a blank cartridge is to cycle self loading
guns, preferably without allowing any dangerous particles or
emissions to leave the barrel of the gun.
[0003] However, presently, all known blank cartridges suffer
several disadvantages. Firstly, without the benefit of a bullet
sited at the front of the cartridge, the blank cartridge often
feeds through and jams the internal mechanics of the gun.
[0004] Furthermore, to develop the back pressures required to
operate the gun's reloading mechanism, special blank firing
adapters are usually required. These adapters spoil the balance and
handling of a gun.
[0005] It is also known that conventional blank cartridges emit
toxic gases and debris from the barrel of the gun after firing, are
limited in power and therefore are only suitable for a small number
of gun types and calibres.
SUMMARY OF THE INVENTION
[0006] It is an object of the present invention to solve the
aforementioned problems by providing a blank cartridge that will
cycle most known types of self loading small calibre gun without
the use of external adapters.
[0007] Accordingly, in a first aspect, the invention provides a
blank pyrotechnic cartridge for use in a firearm, the cartridge
comprising a cartridge casing having a bullet-like projection
extending forwardly therefrom, the bullet-like projection being
retractable through an opening in the casing when the cartridge is
fired, the cartridge being axially expandable in a rearwards
direction in use to move the breechblock of a firearm to recycle
the firearm, the cartridge optionally having sealing means for
preventing propellant gases from escaping through the opening upon
firing.
[0008] In another aspect, the invention provides a blank cartridge
(e.g. a pyrotechnic cartridge) comprising a cartridge casing having
a bullet-like projection extending forwardly therefrom, the
bullet-like projection being retractable through an opening in the
casing when the cartridge is fired, sealing means being provided
for preventing propellant gases from escaping through the opening
upon firing; the cartridge being axially expandable in a rearwards
direction in use to move the breechblock of a firearm to recycle
the firearm.
[0009] In the cartridges of the invention, the expandable cartridge
casing can comprise a piston portion slidably received within a
sleeve portion. For example, the cartridge casing can have a nose
portion, the sleeve portion extending rearwardly of the nose
portion. The bullet-like projection can be connected to or formed
integrally with the piston portion and, in one embodiment, the
piston has a hollow rear portion from which the bullet-like
projection extends forwardly. The hollow rear portion can contain a
pyrotechnic composition.
[0010] In one preferred embodiment, the invention provides a blank
cartridge including a sleeve extending rearwardly from a nose
portion, and a piston slidably disposed within the sleeve; the
piston having at its forward end a spigot slidably received in a
channel through the nose portion and extending forwardly of the
nose portion, the piston having at its rearward end a chamber
containing a pyrotechnic composition; an expansion chamber being
provided within the sleeve between the piston and the nose portion,
one or more gas channels being provided between the pyrotechnic
composition in the piston and the expansion chamber; whereupon
after ignition of the pyrotechnic composition, expanding gas
passing through the or each gas channel into the expansion chamber
moves the piston rearwardly in the sleeve, the rearward movement of
the piston causing the gun to recycle.
[0011] Preferably, the piston is hollow and one or more gas
channels are provided between the hollow interior of the piston and
the expansion chamber.
[0012] Accordingly, in a particularly preferred embodiment, the
invention provides a blank cartridge including a sleeve extending
rearwardly from a nose portion, and a hollow piston slidably
disposed within the sleeve; the piston having a spigot slidably
received in a channel through the nose portion and extending
forwardly of the nose portion; an expansion chamber being provided
within the sleeve between the hollow piston and the nose portion,
one or more gas channels being provided between the hollow interior
of the piston and the expansion chamber; whereupon after ignition,
expanding gas passing into the expansion chamber moves the piston
rearwardly in the sleeve, the rearward movement of the piston
causing the gun to recycle.
[0013] The expansion chamber can be defined by a radially inner
surface of the sleeve, a generally axially facing surface of the
piston and a generally axially facing surface of the nose portion.
The expansion chamber can be, for example, of generally annular
configuration, surrounding the axially inner end of the spigot.
[0014] In one preferred embodiment, the spigot is sealed within the
channel through the nose portion by sealing means, for example
circumferential sealing means such as an `O`-ring, sited in a
circumferential recess around the spigot. This prevents or
minimises the escape of gases and other emissions from the barrel
of the gun after firing.
[0015] The spigot typically is of a length such that after
ignition, all or the greater part of its length is withdrawn into
the nose portion as the cartridge is expanded. This can be achieved
for example by connecting the spigot to that portion of the
expanding cartridge casing which is thrown rearwardly upon
ignition.
[0016] The maximum extent of expansion of the cartridge casing is
chosen such that when fully expanded, the cartridge can still be
ejected from the gun in the normal way.
[0017] In yet another aspect, the invention provides a method of
feeding blank ammunition into the barrel of a gun comprising the
step of loading the gun with a blank cartridge as hereinbefore
defined.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] An embodiment of the invention will now be described with
reference to the following diagrammatic drawings in which:
[0019] FIG. 1 is a longitudinal section through a blank gun
cartridge, prior to firing, according to one embodiment of the
invention; and
[0020] FIG. 2 is a longitudinal section through the gun cartridge
shown in FIG. 1 after the blank cartridge has recycled.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] A blank gun cartridge 2 according to the present invention
is illustrated in FIG. 1. The cartridge 2 comprises a cylindrical
cartridge case 4 with an in-turned flange 6 at the rearward end.
The forward end of the casing comprises a nose portion 8, which in
this embodiment is in the form of a plug, from which sleeve 4
extends in a rearwards direction. The plug 8 has an axial bore
10.
[0022] The inner surface of the sleeve and the rearward surface 12
of the plug define a piston chamber 14. A piston 16 is slidably
contained within the piston chamber 14 and has a pair of outwardly
extending flanges 18 at its forward end. Nested between the flanges
18 and surrounding the piston is an `O`-ring 20 to provide a seal
between the forward end of the piston and the inner surface of the
casing.
[0023] A pyrotechnic composition 22 is housed at the rearward end
of the piston 16. Extending from the pyrotechnic composition to the
forward end of the piston is a first gas expansion chamber 24. At
the head of the gas expansion chamber 24, gas channels 26 allow the
flow of propellant gas from the first expansion chamber 24 into a
second expansion chamber 14a (which corresponds to the expansion
chamber defined in the claims appended hereto), which is defined by
the space between the piston head and the rearward surface 12 of
the plug.
[0024] A spigot 28 extends from the forward end of the piston and
is slidably contained within the axial bore 10 of the plug. Spigot
28 is surrounded by O-ring 30 which provides a seal with the inner
surface of the axial bore 10.
[0025] In operation, the pyrotechnic composition 22 is activated by
the impact of the firing pin P and the propellant gas formed by
ignition of the composition expands into the first gas expansion
chamber 14 and then through the gas channels 26 between the first
gas expansion chamber 14 and the second expansion chamber 14a at
the front of the piston. The pressure of expanding gas in the
second expansion chamber forces the piston (and with it the spigot)
to move rearwardly relative to the outer casing 4. Thus the piston
is propelled rearwardly against the breech block B to recycle the
firearm.
[0026] The extent of rearwards movement of the piston, and hence
the degree of expansion of the cartridge casing is limited by the
flanges 18 on the forward end of the piston which engages with the
flange 6 on the rearward end of the casing 4 (FIG. 2).
[0027] As the cartridge casing expands and the piston 16 is
propelled rearwardly, the bullet shape presented by the spigot is
withdrawn into the cartridge keeping the overall length of the
cartridge substantially the same as a normal spent cartridge and
thereby allowing the cartridge to be ejected in the normal way.
[0028] As can be seen from FIGS. 1 and 2, at least a portion of the
spigot 28 remains in the bore 10 after firing. An advantage of this
is that it prevents relative pivoting movement taking place between
the piston and the casing as the piston moves rearwardly out of the
casing, eliminating the risk of the base section of the piston
bending relative to the axis of the assembly and missing the
cartridge eject mechanism of the gun.
[0029] One advantage of the blank cartridge of the present
invention is that the presence of an `O`-ring seal 30 on the spigot
prevents any gas escaping from the cartridge in cases where zero
emissions are required. A further advantage, which arises from the
presence of the bullet-like projection, is that the cartridge feeds
from the magazine into the firing chamber much more easily and with
considerably reduced likelihood of jamming.
[0030] It is to be understood that the foregoing is merely
exemplary of one embodiment of the invention and that modifications
can be made thereto without departing from the scope of the
invention.
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