US20070272111A1 - Low Energy Training Cartridge - Google Patents

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Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F42—AMMUNITION; BLASTING
  • F42B—EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION
  • F42B5/00—Cartridge ammunition, e.g. separately-loaded propellant charges
  • F42B5/26—Cartridge cases
  • F42B5/30—Cartridge cases of plastics, i.e. the cartridge-case tube is of plastics
  • F42B5/307—Cartridge cases of plastics, i.e. the cartridge-case tube is of plastics formed by assembling several elements
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F42—AMMUNITION; BLASTING
  • F42B—EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION
  • F42B5/00—Cartridge ammunition, e.g. separately-loaded propellant charges
  • F42B5/02—Cartridges, i.e. cases with charge and missile

Definitions

• the present invention relates to ammunition, particularly non-lethal ammunition intended for use in training and war games.
• the invention has particular application in cartridges in which a rearwards movement of a portion of the cartridge is used to initiate the recycling of an automatic or semi-automatic firearm.
• FIG. 1 of the accompanying drawings An example of such a cartridge is illustrated in FIG. 1 of the accompanying drawings.
• a problem that arises with these prior art cartridges is that they perform inconsistently when used in guns of the same calibre but made by different manufacturers. This is due to design variations between guns of different manufacturers, variations which the manufactures claim, when used in conjunction with live ammunition, provide certain technical advantages. These variations, discussed in more detail in the description of FIG. 1 given below, can result in different degrees of gas loss and volume related pressure variations around the bullet.
• the present invention aims to provide a novel low energy cartridge which allows more consistent and predictable performance when firing non-lethal ammunition from weapons of the same calibre, but different manufacturer.
• a low energy cartridge comprising:
• a rear telescopically slidable portion disposed, in use, to be telescopically extendable with respect to the outer casing in a direction towards the breech-block of a firearm;
• a front telescopically slidable portion disposed, in use, to be telescopically extendable with respect to the outer casing in a direction towards the barrel of a firearm;
• the cartridge further includes a projectile received in the front portion of the cartridge, the projectile comprising a bullet which is configured such that, in use, the bullet remains sealed in the front portion of the cartridge until a portion of it has entered the rifled part of the barrel of the firearm.
• the means for causing the telescopically slidable portions to telescopically extend include a gas releasing device positioned to the rear of the rear telescopically slidable portion, an open ended gas passage extending through the portion and forwardly of the gas releasing device and a closure member sealingly slidably located in the gas passage.
• the gas releasing device may be a primer.
• the means for causing the portions to telescopically slide comprise a primer positioned towards the rear of each of the front and rear telescopically slidable portions.
• the means may comprise a primer positioned to the rear of the rear portion which in turn ignites a propellant charge causing both portions to telescopically slide.
• the propellant charge may also, optionally, propel a projectile seated in the gas passage of the front portion.
• this primer may be initiated by percussion, for example on impact by the aforementioned closure member or, by chemical action of a component of gas released in the gas passage of the rear portion.
• the cartridge is loaded in the firearm with both telescopically slidable portions retracted into the outer casing.
• a projectile is positioned in the open end of the gas passage of the front portion.
• the firing pin strikes the primer causing release of gas into the gas passage extending forwardly of the primer.
• the closure member is caused to slide along the gas passage at increasing speed towards the primer of the second telescopically slidable portion.
• the expanding gas forces the rear telescopically slidable portion to extend towards the breach block of the firearm, travelling in an opposing direction to the closure member.
• the accelerating closure member strikes the primer of the front portion causing release of a second quantity of gas into the gas passage extending forwardly of this second primer. As it expands, this second quantity of gas forces the projectile out of the open ended gas passage and into the barrel of the firearm.
• the front telescopically slidable portion extends before the bullet is propelled through the barrel of the firearm.
• the portion thus creates a seal between the cartridge and the barrel to enable all of the propellant gas, without pressure drops or gas losses, to propel the bullet up the barrel. This overcomes inconsistencies in performance of cartridges in firearms of varying manufacturer's designs.
• the outer casing is shaped so as to include at or near each end an inwardly jutting surface which serves to stop the telescopically slidable portions separating from the outer casing when they extend.
• the inwardly jutting surface comprises an annular flange having an inner radius which is slightly smaller than the largest radius of the corresponding, telescopically slidable portion.
• the closure member is conveniently a plug which has a cross section in a direction perpendicular to the direction of travel of the telescopically slidable portions, of similar shape and size to that of the gas passage of the first telescopically slidable portion.
• the closure member is substantially spherical.
• the closure member may, optionally, comprise a steel ball.
• the closure member may comprise a ball of plastic material.
• the outer surface of the closure member is desirably selected to be of a low friction material so as to allow the member to easily slide along the gas passage when the first gas is released.
• a gas tight seal is provided between at least the rear telescopically slidable portion and the outer casing and optionally also the front telescopically slidable portion and the outer casing.
• Either or both of the primers may in turn ignite a propellant charge.
• FIG. 1 shows schematically a typical cartridge as is known from the prior art, correctly located in the chamber of a firearm.
• FIG. 2 shows in cross section an embodiment of a telescopically expandable cartridge in accordance with the invention located in the chamber of a firearm, prior to firing;
• FIG. 3 shows the embodiment of FIG. 2 shortly after the firearm has been fired but before the projectile is propelled into the barrel of the firearm;
• FIG. 4 shows the embodiment of FIG. 3 at a later moment when the projectile has been propelled into the barrel of the firearm.
• FIG. 1 illustrates schematically a typical cartridge Z as is known from the prior art.
• dimension A is a constant used by all firearm manufacturers for a given ammunition type.
• the cone shaped surface B is not common to all manufacturers designs and may be plane and smooth.
• the cartridge may make a seal between the rifled barrel X and the chamber Y or it may have grooves that run from the surface with dimension C across the cone shaped face and along the surface with dimension A thereby rendering it impossible to make a seal between the rifled barrel X and the chamber Y.
• C and D may vary from manufacturer to manufacturer as may diameters E and F.
• H represents the direction of extension of a telescopically expanding low energy cartridge during recycling.
• the dimension I may vary from manufacturer to manufacturer.
• manufacturers use slightly varying breech and chamber dimensions and configurations (for example fluted chambers) for use with live ammunition.
• FIG. 2 illustrates a cartridge in accordance with the invention.
• the cartridge of the invention comprises an outer casing 4 in to which are telescopically slidably arranged a rear portion 1 and front portion 6 .
• the rear portion includes a primer 2 sited to the rear of the portion where, in use, it can be initiated in striking by a firing pin of the firearm (not shown).
• an annular flange 9 which includes an annular recess which receives a sealing ring 10 .
• the sealing ring 10 provides a gas tight seal which prevents gases released from the primer 2 escaping from the rear of the cartridge.
• the inner radius of the annular protrusion is selected to be smaller than the outer radius of the flange 9 such that, when the rear portion 1 extends, it is prevented from separating from the casing by flange 9 abutting against protrusion 8 .
• a gas passage 11 extends forwardly of the primer 2 in the rear portion 1 .
• a closure member which may be a steel or plastic ball 3 which has a diameter comparable to that of the diameter of the gas passage 11 .
• the ball 3 acts as a closure member preventing the escape of gas released by the primer 2 from escaping through the open end of the gas passage 11 .
• the ball 3 is, however, slidable within the gas passage 11 .
• the front portion 6 is made from plastic or composite construction of pliable material which serves to seal in the outer casing 4 .
• the pliable nature of the material allows deformation at the interface between the front portion 6 and the entry to the barrel X maintaining a seal even if fluting is present.
• the front portion further comprises a second primer 5 sited towards its rear end.
• a second gas passage 12 extends forwardly of the second primer 5 and opens into a socket 13 configured to receive an end of a bullet or other projectile 7 .
• the smallest diameter (at position 14 ) of the front end of the casing 4 is smaller than the largest diameter (at position 15 ) of the front portion 6 so as to prevent separation of the front portion 6 from the casing 4 when the front portion telescopically extends.
• a bullet 7 is configured such that the bullet 7 remains sealed in the socket 13 of the pliable front portion 6 of the cartridge until the it has entered the rifled part X of the barrel of the firearm. This may be achieved by providing a bullet 7 with a parallel section 7 a , sealed in the socket 13 of the pliable front portion 6 .
• FIG. 3 shows the initial action of the cartridge of FIG. 2 when the firearm is fired.
• a firing pin P strikes the primer 2 in of the rear portion 1 which causes gas to be released into gas passage 11 .
• the pressure of the gas in passage 11 causes ball 3 to travel towards the front portion 6 .
• gas escapes past the ball and begins to force the front 6 and rear 1 portions apart.
• the rear portion 1 extends telescopically towards the breech of the firearm so as to recycle the firearm as is known from the prior art.
• the front portion 6 also telescopically extends so as to seal the front pliable portion at the interface between the guns chamber Y and the barrel X and deposit the front end of the projectile 7 into the barrel X of the firearm.
• the ball 3 strikes the primer 5 of the front portion 6 causing release of gas into gas passage 12 .
• the released gas builds up a pressure behind projectile 7 which ultimately forces the projectile along the barrel X.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Aiming, Guidance, Guns With A Light Source, Armor, Camouflage, And Targets (AREA)

Abstract

Description

Claims (18)

Applications Claiming Priority (3)

Publications (1)

Family

ID=29797851

Family Applications (1)

Country Status (5)

Cited By (5)

Families Citing this family (4)

Citations (3)

• 2003
  • 2003-11-26 GB GBGB0327492.5A patent/GB0327492D0/en not_active Ceased
• 2004
  • 2004-11-26 EP EP04819718A patent/EP1697692A1/en not_active Withdrawn
  • 2004-11-26 WO PCT/GB2004/004994 patent/WO2005054775A1/en active Application Filing
  • 2004-11-26 US US10/580,577 patent/US20070272111A1/en not_active Abandoned
  • 2004-11-26 CA CA002547395A patent/CA2547395A1/en not_active Abandoned

Patent Citations (3)

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