US3682097A

US3682097A - Firearm cartridge

Info

Publication number: US3682097A
Application number: US855936A
Authority: US
Inventors: Gad Anders Rausing
Original assignee: LADCO ENTERPRISES Ltd
Current assignee: Tetra Pak Developpement SA
Priority date: 1968-10-14
Filing date: 1969-09-08
Publication date: 1972-08-08
Anticipated expiration: 1989-08-08
Also published as: SE324301B; FR2022265A1; CH515482A; NL6914427A; SU367622A3; DE1951006C2; DE1951006A1; GB1229119A; CA930243A; JPS4828240B1

Abstract

A firearm cartridge having a propulsion charge for a bullet and a sealing element at the rear thereof composed of a combustible material which burns more slowly than the propulsion charge so as to maintain its sealing effect while the propulsion charge is exploded and thus prevent flashback but will subsequently completely burn out to leave the cartridge chamber of the firearm clear for reloading.

Description

United States Patent 1151 3,682,097 Rausing 1451 Aug. 8, 1972 [54] FIREARM CARTRIDGE 2,632,391 3/1953 Kintzinger 102/38 [72 lnvemor: Gad Anders musing, Land, Sweden 3,345,945 10/1967 Quinlan et a1. ..102/38 3,396,658 8/1968 Scanlon, Jr. et a1. 102/38 [731 Asslgnw Enterprises limited, Hamfl- 2,299,465 10/1942 Coffman 102/1910. 1

ton, Bermuda 1 [22] Filed: Sept. 8, 1969 FOREIGN PATENTS OR APPLICATIONS 455,382 1/1928 Germany ..l02/D1G. l App! 855336 7,193 1891 Great Britain ..102/43 P 519,341 3/1940 Great Britain ..102/D1G. 1 [30] Foreign Application Priority Data 0C1. 14, [968 Sweden ..13799 Prim? W Slab Attorney-fierce, Scheffler & Parker [52] US. Cl ..l02/38, l02/D1G. l, 102/40,

102 44 [57] ABSTRACT 51 1m. (:1 ..F42b 9/16 A firearm camid h 1 h f ge avlng a propu SlOn c arge or a [58] Field of Search ..102/38, DIG. 1, 44, 45, 86.5, bullet and a sealing element at the rear thereof 102/40 posed of a combustible material which burns more slowly than the propulsion charge so as to maintain its [56] References Cited sealing effect while the propulsion charge is exploded UNITED STATES PATENTS and thus prevent flashback but will subsequently 1 t 1 b t t 1 th art 'd h h f 487,125 ll/l892 DeLatouche........l02/D1G. 1 3,353, ?,,fi gee am em 1,353,118 9/1920 Thompson ..102/41 1,808,877 6/1931 Young ..102/40 6 Chins, 1 Drawing figure FIREARM CARTRIDGE This invention relates to a firearm cartridge, comprising bullet and propulsion charge.

It has been known for a long time how to combine the bullet and propulsion charge in a self-exploding cartridge which usually also includes a primer. In known cartridges, the propulsion charge is usually contained in a cartridge case of metal, cardboard, plastic or some other similar material. There are usually one or more projectiles pressed into one end wall whose center portion is usually fitted with a primer, through the agency of which the propulsion charge can be ignited. The said end wall, which is usually made of metal, also has an important duty as a gastight seal between the breech and the bolt, in order to prevent flashback when the bullet is fired. It is quite natural that this duty to act as a seal is very important, since the flashback which may arise if there were no seal may easily injure the person firing the weapon and/or affect the working and life of the mechanism.

The self-exploding cartridges available are certainly very efficient from the point of view of forming a gastight seal and are convenient to handle, but they have the drawback that they are comparatively expensive and that the case which remains in the chamber after firing must be removed before a new cartridge can be inserted. A very high proportion of the cost of the cartridge is due to the cost of the case. If the case can be eliminated, the cartridge can be made considerably cheaper and naturally also lighter, and the absence of the case means that the mechanism of automatic weapons can be made simpler and lighter, since there is no need for an extractor to withdraw the case from the chamber after the bullet has been fired. The cartridge can also be made shorter which in turn makes possible a shorter and lighter mechanism and a higher firing rate.

There is no difficulty involved in moulding a body of powder or some other explosive material into a certain shape defined by the shape of the chamber of the weapon and thereby also partly embedding a bullet in the moulded body, and the techniques for such operations have already been evolved. Solution of the sealing action is a greater problem, and it seems inescapable that the cartridge must be provided with some kind of sealing washer or sealing flange in order to prevent the occurrence of flashback.

This invention provides a solution to this problem, without however relinquishing for this reason the requirement that there shall be no need for portions of the cartridge to be removed from the chamber after firing. The invention is thereby characterized by the fact that the propulsion charge consists of a moulded, preferably cylindrical, body of an explosive material, for instance powder, into which body there is affixed a bullet, and by the fact that the said preferably cylindrical body exhibits a ringshaped or washer-shaped sealing device which surrounds the end of the propulsion charge, which device entirely consists of a combustible material. One constructional version of the invention will be described below by reference to the attached diagrammatic drawing which shows a cartridge in accordance with the invention.

The cartridge shown in the FIGURE consists of a propulsion charge 1 made up of a moulded body of powder. The bullet is denoted 2 and the rear anchorage of the bullet by 5. The sealing device is denoted 3 and the primer 4.

The powder material is moulded in a mould that has been made to fit the shape of the chamber of the weapon in which the cartridge is to be used. In conjunction with the moulding operation, the propulsion charge 1 is in a suitable manner joined onto the bullet 2 which may at its rear end have a dovetail anchorage, by means of which the bullet 2 can be embedded in the propulsion charge 1. The propulsion charge 1 is also formed at its rear end in such a way that the sealing device 3, produced in a separate operation, can be fitted into the propulsion charge. The sealing device 3 consists in the version shown of a washer-shaped end portion with a flange 6 and a central hole. The sealing device 3 may for instance be made of nitrocellulose or some other easily combustible material which is yet comparatively stable mechanically. The primer 4 situated at the central part of the sealing device 3 consists of a primer containing a charge that is ignited by a firing pin being thrown against the wall of the primer 4. [n a conventional primer, both the anvil and the case are made of metal. In primers for cartridges of the type in accordance with the invention, they are made from an entirely combustible material with a combustion time the same as, or shorter than, that of the charge material. The seal and the primer can be made in one piece. lgnition can also take place in some other way, e.g., by means of compressed air or an electrical primer which directly actuates the propulsion charge.

When the cartridge in accordance with the drawing is to be fired, it is first placed in the chamber, which has been adapted to fit the cartridge, of a weapon. In the example shown, the cartridge and naturally the chamber of the weapon also are slightly conical, but it is naturally also possible to have a cylindrical chamber.

After the cartridge has been inserted into the chamber and this has been locked, the propulsion charge 1 is ignited and undergoes rapid combustion, whereupon a high pressure develops in the chamber. This high pressure has the effect that the sealing device 3 is forced backwards against the rear wall of the chamber and that the bullet 2 is ejected through the barrel of the weapon. The propulsion charge 1 is naturally not consumed instantaneously, and generally speaking combustion of the propulsion charge proceeds the whole time that the bullet 2 is inside the barrel, and owing to the increasing pressure, the bullet is accelerated so as to reach its maximum velocity at the muzzle. After the bullet has left the barrel, the pressure in the barrel and chamber will naturally drop. During the time that the high pressure in the chamber is acting, there are high stresses set up on the sealing device 3, which fact prevents hot gases, the flashback, being ejected through the rear wall of the chamber. Since the sealing device 3 is made from a combustible material, combustion of the sealing device commences simultaneously with ignition of the propulsion charge 1. The combustion times of the propulsion charge 1 and the sealing device 3 respectively are however adjusted in such a way that the sealing action of the sealing device is maintained during the whole of the combustion time of the propulsion charge 1, which time is however very short. This means that the dimensions of the sealing device 3, i.e., preferably its thickness, must be adapted to the combustion velocity of the material in such a way that complete combustion of the sealing device 3 does not take place before the propulsion charge 1 has completely burned away or the bullet has left the barrel.

it is important that complete combustion of both the propulsion charge and the sealing device takes place so that such solid combustion products as may hinder insertion into the chamber of a new cartridge are not left behind.

It is possible to produce sealing devices of the above type which are completely burned 0.001 0.5 second after the bullet has been fired, whereby the sealing device, despite the short combustion time, will have been able to exercise the required sealing action so that there is no flashback when the bullet is tired.

It is thus possible, using cartridges in accordance with the invention, to achieve a very high firing rate in automatic weapons, and at the same time ammunition costs will be considerably lower and there will be no refuse" in the shape of empty cartridge cases.

] claim:

l. A firearm cartridge comprising a propulsion charge of explosive material molded in the form of a body having a substantially circular cross section, a bullet element affixed to the forward end of said body for propulsion thereby, a washer-like sealing means at the opposite end of said body, said washer-like sealing means being composed of a combustible material having a burning rate slower than the burning rate of said propulsion charge to provide a sealing action during the entire burning of said propulsion charge and thus prevent flashback and be consumed by its own combustion, and primer means for igniting the propulsion charge.

2. A cartridge as claimed in claim 1 wherein said propulsion charge has an annular recess thereabout and the washer-like sealing means comprises a rear end wall and an annular flange thereabout forming a coex' tensive surface with said propulsion charge, said flange being seated in said annular recess of the propulsion charge.

3. A cartridge as claimed in claim 1 wherein said primer means comprises a primer cap disposed centrally of said washer-like sealing means.

4. A cartridge as claimed in claim 1 wherein the washer-like sealing means is composed of a combustible material which will be completely burned away in 0.001 to 0.5 seconds after ignition of said propulsion charge.

5. A cartridge as claimed in claim 1 wherein the propulsion charge is composed of a powder charge and the washer-like sealing means is composed of nitrocellulose.

6. A cartridge as claimed in claim 1 wherein the primer means and the washer-like sealing means are made in one piece.

III 0 l

Claims

1. A firearm cartridge comprising a propulsion charge of explosive material molded in the form of a body having a substantially circular cross section, a bullet element affixed to the forward end of said body for propulsion thereby, a washerlike sealing means at the opposite end of said body, said washerlike sealing means being composed of a combustible material having a burning rate slower than the burning rate of said propulsion charge to provide a sealing action during the entire burning of said propulsion charge and thus prevent flashback and be consumed by its own combustion, and primer means for igniting the propulsion charge.

2. A cartridge as claimed in claim 1 wherein said propulsion charge has an annular recess thereabout and the washer-like sealing means comprises a rear end wall and an annular flange thereabout forming a coextensive surface with said propulsion charge, said flange being seated in said annular recess of the propulsion charge.