GB1601917A

GB1601917A - Ammunition for small arms

Info

Publication number: GB1601917A
Application number: GB44737/76A
Authority: GB
Original assignee: Hilvenna Ltd
Current assignee: Hilvenna Ltd
Priority date: 1976-10-28
Filing date: 1976-10-28
Publication date: 1981-11-04
Also published as: AU2959777A; BE860116A; SE7711447L; ZA776038B; FR2369537A1; ES463587A1; JPS5355698A; DE2747932A1

Description

(54) IMPROVEMENTS IN OR RELATING TO AMMUNITION FOR SMALL ARMS (71) We, HILVENNA LIMITED, a British Company, of 5 Rushton Close, Balsall Common, Coventry, West Midlands, England, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention concerns improvements relating to cartridge ammunition for small arms, such as pistols rifles and automatic small arms, and to small arms adapted or modified to utilise such ammunition.

According to the present invention there is provided a cartridge device comprising an elongate hollow casing provided with an opening at one end and a missile holder at the opposite end, an elongate pressure cylinder slidably accommodated in the casing and provided with a valve arrangement to admit gas into and release gas from the pressure cylinder via an opening in one end of the pressure cylinder, an abutment member fixedly located in the hollow casing between the valve arrangement and a mouth of the missile holder, and a spring arranged to bias the valve arrangement to a closed condition, wherein the missile holder incorporates or is provided with missile retaining means to retain a missile in the mouth; and wherein the valve arrangement is openable by movement of the pressure cylinder towards the mouth against the bias of the spring to cause the abutment member to open the valve means to allow compressed gas to flow from the pressure cylinder and longitudinally of the abutment member to the mouth to expel a missile from the mouth.

The invention will be described, by way of example only, with reference to the accompanying diagrammatic drawings.

In the drawings:- Figure 1 shows an enlarged cross-section of a first embodiment of a cartridge device of the invention, with parts of a small arm and a missile shown in broken outline; Figure 2 shows part of a slightly modified form of said first embodiment, disposed in a charging device; Figure 3 shows an enlarged cross-section of a second embodiment of cartridge device of the invention; and Figures 4 to 6 show details of a slightly modified form of the second embodiment.

The first embodiment cartridge device comprises a substantially cylindrical metal casing 10, a pressure chamber defined by a metal cylinder 11 disposed in the casing, a valve arrangement 12 disposed at one end of the pressure cylinder, a fixed abutment member 13 adjacent the valve arrangement, and retaining means 14 disposed in a mouth 15 of a missile holder provided at one end of the casing.

The casing 10 has a calibre or diameter and base flange 16 matching those of a standard .303 rifle cartridge, has an open base end, and the mouth is slightly greater than 0.177 inch diameter.

The cylinder 11 is slidable in the casing 10 and has one open end, and partially accommodates the valve arrangement 12. The latter comprises a plastics valve seat member 17, in which member 17 a part conical head 18 of a valve member disposed in the pressure chamber is normally engaged by means of a bias. The valve member has an extension 19 which extends out of the pressure chamber.

The bias is provided by a closure coil spring 20 captive in the cylinder and co-axial with the pressure chamber. The periphery of the head 18 is fluted or grooved, so that if an excess gas pressure in the cylinder causes the head to enter into the valve seat member beyond a predetermined limit, the periphery of the head will provide escape passages for the gas in the cylinder. The valve pin 19 extends from the cylinder to a central socket in the abutment member 13. The abutment member 13 is longitudinally ribbed to pro vide passage 13B, is ofhard plastics or metal, and is press fitted into the casing 10.

The retaining means 14 is in the form of a resilient "O-ring" seated in an annular channel in the missile holder, and is adapted to retain a standard .177 calibre air gun pellet 21 in the mouth 15.

As shown in Figure 2, the base portion of the casing 10 may be internally provided with retaining means in the form of an annular channel in the base portion of the casing and a further "O-ring" 22 or a circlip to retain the cylinder 11 in the casing.

The cylinder 11 is chargeable with compressed air by means of a charging device represented schematically in Figure 2. The charging device comprises a pump having a body 30, a piston 31, a duct 32 and a socket for the mouth end of the cartridge casing, together with a base 33. The base and body are relatively movable to cIamp the casing 10 therebetween to permit air to be pumped by the piston into the cylinder 11. A cylinder support boss 34 may be provided on the base 33, and the wall of the body 30 may be extended to surround the cartridge device, i.e. to form the wall of a protective charging chamber around the casing 10 as indicated partially by broken lines 35.

The stroke and mechanical advantage of the pump is preferably matched to the size of the cylinder and the required missile velocity to give satisfactory charging in a single manually operated stroke. In the example.the pump should be able ta charge the cylinder to a high pressure of, for example, 600 psi for Great Britain, or 1000 psi for U.S.A. and other countries where the use of high power air weapons is unrestricted.

For use in Great Britain a charging and valve relief pressure of 600 psi in a cylinder 3/64th of a cubic inch, will bring the energy imparted to a .177 slug below the limit set by the present laws, but the charging pressure, pellet diameter, valve relief pressure and cylinder capacity can be modified to give higher missile energies.

After charging, the pellet 21 is pushed into the mouth so that the pellet skirt is thrust past the "O-ring" 14 whereby to load the cartridge device to form a round of ammunition.

The so charged and loaded cartridge device may then be loaded as a round of ammunition into the firing chamber of a suitable gun, or into a magazine or like holder. The cartridge device can be "fired" or discharged by thrusting the cylinder 11 towards the mouth 15 so that the pin 19 strikes the abutment member 13 and is forced off the valve seat member 17 to allow the compressed air to escape and flow along the abutment member, via passage means connecting the valve and the mouth, whereby to drive the pellet from the mouth.

The passage means in this embodiment includes the interior of the member 17 and the passages 13B.

The relevant parts of a suitable gun for using the cartridge devices are shown in broken lines in Figure 1, and these parts include a wall 40 defining a firing chamber in which the cartridge device is accommodated, and a barrel 41, together with a liner 42 having a resilient seal 43 at one end, and a firing pin 44.

The gun in this example is a well known standard .303 service rifle, the wall 40 and barrel 41 being unchanged, to which a modifying kit comprising the liner 42, seal 43 and the firing pin 44 have been fitted. The firing pin 44 is in the form of a broad headed blunt projection on a replacement bolt which is substituted for the standard bolt having a pointed firing pin. The liner 42 is of standard air gun .177 bore and the seal 43 is fitted at the chamber end of the liner to engage the mouth end of the casing 10, as shown diagrammatically in Figure 1. However, the firing pin 44 may be in the form of a blunt cap adhesively secured to the original firing pin to prevent the cylinder 11 being damaged.

The mechanism driving the firing pin may be modified by incorporating a non-standard driving spring.

The modification of the gun may be made permanent to render the gun unable to fire a firearms cartridge by disposing of the original bolt and driving spring, brazing the liner in position and drilling or cutting holes or slots transversely into the barrel, to remove the gun from the scope of the firearms laws.

The general form of the second embodiment shown in Figures 3 to 6 is similar to that of the first embodiment, and similar reference numbers with a suffix A are used to indicate parts in the second embodiment similar to those in first embodiment.

In the second embodiment the casing 10A has a reduced basal opening, and at the other end a fixed-in missile holder 50 defines the mouth 15A and the fixed abutment member 13A, so that the latter is located by the missile holder. The passage means comprises a passage 51 provided in the fixed abutment member, which passage extends longitudinally within the abutment member between side ports 52 and the mouth 15A.

The valve arrangement 12A is disposed in the pressure chamber, and includes the seat member 17A which provides an annular seat against which a plastics valve member 53 abuts. The valve member 53 has an axial recess, and the abutment member 13A extends into the cylinder I IA and through the seat member 17A to engage in the axial recess.

The cylinder 1 lA has a thick basal projection 54 which extends into the basal opening in the casing 10A, and the projection 54 is sufficiently robust to withstand the impact of a firing pin. The projection 54 joins the body of the cylinder body entering the basal aperture.

The mouth 15A of the missile holder is adapted to serve also as frictional retaining means, and for this purpose the diameter of the mouth is fractionally smaller than the skirt diameter of the pellet, so that the pellet is a push fit in the mouth.

The external shape of the casing 10 or 1 0A may be varied to suit the intended use. For example the casing 10A in Figure 3 is for a cartridge device for a 0.38 revolver, whereas the casing 10A in Figure 4 is for a cartridge device for the SLR rifle and has an ejector rim 60 and ejector groove 61 around the base for the self-loading mechanism of the rifle.

The mouth diameter is not proportional to the casing diameter (compare Figures 4 and 5), and the open end of the mouth may have a chamfer 62 as shown in Figure 5.

The base end of the cylinder 11 or 11A may be varied in shape. and the size and shape of the projection and step may be varied. For example, the projection 54 shown in Figure 3 is relatively wider but shorter than the equivalent projection 64 of the cylinder 11A for the SLR cartridge device shown in Figure 6, and in the latter case the shoulder is inclined to compliment the internal form of the basal end of the casing 10A shown in Fig. 4.

In use, the second embodiment can be charged, loaded and fired in the sane manner as the first embodiment, but the second embodiment can be charged to higher pressures, and when fired, compressed air flows between the valve member 53 and the annular seat directly into the passage 51 in the abutment member so as not to build up any back pressure within the casing.

It will be readily appreciated that the invention enables a user io employ a gun of firearms form as an air weapon whereby to reduce the cost, noise and danger involved in pra. ti.ing, and removes the need for a firearms target range and all the expensive saí . v r pleasures and licences involved therein. Furthermore, a number of such cartridge devices can be ioaded into a magazine to 'ive a normal repeater action in a repeating or automatic gun, which is not possible with a standard air weapon, and the cartridge devices can even be employed in a replica or model mechanically actuated machine gun of, for example, Gatling or Maxim form.

The relative proportions of the cartridge devices can be altered to enable such devices to be employed in revolvers and pistols after suitable modification, to enable quick draw and police training to be practiced on the actual type of firearms in service.

WHAT WE CLAIM IS: 1. A cartridge device comprising an elongate hollow casing provided with an opening at one end and a missile holder at the opposite end, an elongate pressure cylinder slideably accommodated in the casing and provided with a valve arrangement to admit gas into and release gas from the pressure cylinder via an opening in one end of the pressure cylinder, an abutment member fixedly located in the hollow casing between the valve arrangement and a mouth of the missile holder, and a spring arranged to bias the valve arrangement to a closed condition, wherein the missile holder incorporates or is provided with missile retaining means to retain a missile in the mouth; and wherein the valve arrangement is openable by movement of the pressure cylinder towards the mouth against the bias of the spring to cause the abutment member to open the valve means to allow compressed gas to flow from the pressure cylinder and longitudinally of the abutment member to the mouth to expel a missile from the mouth.

2. A cartridge device as claimed in claim 1, wherein the retaining means comprises a resilient O-ring provided in the mouth.

3. A cartridge device as claimed in claim 2, including a missile in the form of an air gun pellet having a skirt, and wherein said skirt is engaged by the O-ring.

4. A cartridge device as claimed in claim 1, 2 or 3, wherein the missile holder is secured to the casing and serves to locate the abutment member in the casing.

5. A cartridge device as claimed in any preceding claim further comprising retaining means provided in said one end of the casing to retain the pressure cylinder in the casing.

6. A cartridge device as claimed in any preceding claim, wherein the valve arrangement comprises a valve member which is located in the pressure cylinder; wherein the spring is located in the pressure cylinder and urges the valve member to abut a seating provided by the pressure cylinder; and wherein the abutment member extends into the opening in said one end of the pressure cylinder and engages said valve member.

7. A cartridge device as claimed in claim 6, wherein the abutment member provides an internal passage which extends from said mouth to ports in said abutment member, from the cylinder which ports are disposed adjacent to the valve member so as to open into and receive gas from the pressure cylinder when the valve arrangement is open.

8. A cartridge device as claimed in claim 6 or 7, wherein said valve member is of plastics material.

9. A cartridge device as claimed in any preceding claim, wherein the end portion of the pressure cylinder remote from the open

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. in the casing 10A, and the projection 54 is sufficiently robust to withstand the impact of a firing pin. The projection 54 joins the body of the cylinder body entering the basal aperture. The mouth 15A of the missile holder is adapted to serve also as frictional retaining means, and for this purpose the diameter of the mouth is fractionally smaller than the skirt diameter of the pellet, so that the pellet is a push fit in the mouth. The external shape of the casing 10 or 1 0A may be varied to suit the intended use. For example the casing 10A in Figure 3 is for a cartridge device for a 0.38 revolver, whereas the casing 10A in Figure 4 is for a cartridge device for the SLR rifle and has an ejector rim 60 and ejector groove 61 around the base for the self-loading mechanism of the rifle. The mouth diameter is not proportional to the casing diameter (compare Figures 4 and 5), and the open end of the mouth may have a chamfer 62 as shown in Figure 5. The base end of the cylinder 11 or 11A may be varied in shape. and the size and shape of the projection and step may be varied. For example, the projection 54 shown in Figure 3 is relatively wider but shorter than the equivalent projection 64 of the cylinder 11A for the SLR cartridge device shown in Figure 6, and in the latter case the shoulder is inclined to compliment the internal form of the basal end of the casing 10A shown in Fig. 4. In use, the second embodiment can be charged, loaded and fired in the sane manner as the first embodiment, but the second embodiment can be charged to higher pressures, and when fired, compressed air flows between the valve member 53 and the annular seat directly into the passage 51 in the abutment member so as not to build up any back pressure within the casing. It will be readily appreciated that the invention enables a user io employ a gun of firearms form as an air weapon whereby to reduce the cost, noise and danger involved in pra. ti.ing, and removes the need for a firearms target range and all the expensive saí . v r pleasures and licences involved therein. Furthermore, a number of such cartridge devices can be ioaded into a magazine to 'ive a normal repeater action in a repeating or automatic gun, which is not possible with a standard air weapon, and the cartridge devices can even be employed in a replica or model mechanically actuated machine gun of, for example, Gatling or Maxim form. The relative proportions of the cartridge devices can be altered to enable such devices to be employed in revolvers and pistols after suitable modification, to enable quick draw and police training to be practiced on the actual type of firearms in service. WHAT WE CLAIM IS:

1. A cartridge device comprising an elongate hollow casing provided with an opening at one end and a missile holder at the opposite end, an elongate pressure cylinder slideably accommodated in the casing and provided with a valve arrangement to admit gas into and release gas from the pressure cylinder via an opening in one end of the pressure cylinder, an abutment member fixedly located in the hollow casing between the valve arrangement and a mouth of the missile holder, and a spring arranged to bias the valve arrangement to a closed condition, wherein the missile holder incorporates or is provided with missile retaining means to retain a missile in the mouth; and wherein the valve arrangement is openable by movement of the pressure cylinder towards the mouth against the bias of the spring to cause the abutment member to open the valve means to allow compressed gas to flow from the pressure cylinder and longitudinally of the abutment member to the mouth to expel a missile from the mouth.

ing has a thick basal projection which extends into the opening in the casing.

10. A cartridge device as claimed in any preceding claim, in combination with a charging device, comprising a pump or reservoir adapted to provide compressed gas to charge the pressure cylinder to a predetermined pressure.

11. A cartridge device as claimed in any one of claims 1 to 9 in combination with a small arm having a firing pin, wherein the firing pin is blunt and the arm is adapted so as to be capable of discharging the cartridge device but not a firearms cartridge.