GB1562410A

GB1562410A - Ignition means for propellant charges

Info

Publication number: GB1562410A
Application number: GB39314/76A
Authority: GB
Original assignee: Rheinmetall GmbH
Current assignee: Rheinmetall Industrie AG
Priority date: 1975-09-27
Filing date: 1976-09-22
Publication date: 1980-03-12
Also published as: NO144085B; BE846515A; FR2325900A1; SE7610583L; NO144085C; IT1123661B; FR2325900B1; SE427384B; DE2543223A1; NO763242L

Description

(54) AN IGNITION MEANS FOR PROPELLANT CHARGES (71) We, RHEINMETALL GmbH, of 4 Dusseldorf, Ulmenstrasse 125, Western Germany, a company organised and existing under the laws of Western Germany, 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 relates to an ignition means for a propellant charge contained in a casing e.g. a cartridge case.

In known propellant charges especially rounds of tank ammunition using a powder main charge excessive variations in the ignition delay may occur at a result of the ignition chain leading up to the effective firing of the charge. This is because the package of powder usually fills the cross section of the cartridge or charge casing but the axial combustion channels of the threaded percussion primer only cover the central zone of the package, thus an accurately defined burning rate for the main charge is not ensured.

According to this invention there is provided an ignition means adapted to be located within the base of a case containing a propellant charge, the means comprising a housing with a base provided with a primer cap for ignition by external means (electrical or mechanical), a booster charge coupled with the primer within the housing, axial combustion ports through the top of the housing, and radial combustion ports through the housing wall in the region of the booster charge and communicating with a priming charge positioned around the housing.

The radial combustion ports can be aligned either perpendicularly to or at an angle to the longitudinal axis of the housing.

The primer charge may be of annular or disc shape the central part being in communication during ignition with the axial combustion channels and the side part being isolated from the central part and communicating with the radial combustion channels.

In one construction preferred the housing includes in axial aligment a first booster charge adjacent the primer cap and a second booster charge in contact with the first booster charge, the second booster charge lying adjacent both the axial and radial combustion ports.

It is preferable if the housing containing the booster charge is screw connected with the base, the axial combustion ports being provided in a cap screw connected with the top of the housing.

This invention also provides in combination a casing housing a propellant charge, e.g. a cartridge case or case for a round of ammunition such as a shell, the ignition means being securable within an aperture in the base of the casing, with the radial combustion ports directed towards a priming charge adjacent the propellant charge.

In such an arrangement the priming charge will preferably be annular and lies around the ignition means with the top of the ignition means adjacent the propellant charge. However a disc part of the priming charge may be provided between the top of the ignition means and the propellant charge this part being separate from the annular part of the priming charge.

The accompanying drawings show an embodiment of the ignition means in conjunction with a charge and casing and a modification thereof by way of example: Figure 1 shows an ignition chain from the ignition means to the main charge, Figure 2 shows a modification with a disc shape priming charge.

The propellant charge ignition means has a body la with an external screw thread 2 and an abutment 3, a sealing ring 3a and key recesses 4. The base lh of the body la has a narrow central bore provided with a central contact 5 electrically insulated from the body la. The contact is associated with a primer 6 which is operatively coupled with a first booster charge 7 which is coupled with a second booster charge 8.

The booster charges 7 and 8 are carried in a housing 9 which is screwed into the ignition body la. The booster charge 8 is surrounded by a bowl casing 10 of celluloid or other rapidly combustible substance. At the side of the booster charge 8 are a total of eight radial combustion ports 11, slanting towards the base ib, and provided through the wall of the housing 9. The second booster charge 8 has a sealing cap 12 provided with a total of four axial combustion ports 13.

The propellant ignition means 1 is screwed into the base 14 of the shell or cartridge case 15 so that the sealing ring 3a and stop 3 forms a seal preventing any passage of gas from the ignition means to the cartridge case exterior. The base 14 of the cartridge case 15 is thick but only extends as far as the junction between the body la and the housing 9, so that the radial combustion ports 11 are left open.

The space left within the case 15 and defined by the base 14, the side of the case 15 and the housing 9, is completely or partly filled by an annular priming charge bag 16, which is immediately adjacent the main propellant charge 17, which lies on the cover 12. The main charge consists of a powder package.

As shown in Figure 2, the annular charge 16 may have a central disc like part 16a resting on the cover 12 with the remainder of the charge filling the space in the cartridge case 15. A particular advantage of this type of priming charge is that both the radial combustion ports 11 and the axial combustion ports 13 are in communication as far as ignition is concerned, with the priming charge.

In the breech block 18 of the weapon the electrical striker pin 19 on firing moves forward towards the central contact 5, and the primer 6 is first ignited and subsequently the first booster charge 7 and thus the second booster charge 8 in succession. The eight combustion ports 11 serve to ensure that on combustion of the booster charges 7 and 8 the priming charge 16 is ignif8 starting generally from the base 14 of the cartridge case 15 to ensure that the charge will undergo uniform and complete com bastion propazatinz in the direction of the main charge 17 which burns in a way to ensure radix conversion of the pronellRnt charge 17 into the gas phase.The four axial combustion ports 13 and the eight radial combustion ports 11 combine with the priming charge 16 and 16a to ensure that the ignition chain in the charge is shorter with a reduction in ignition time variations.

WHAT WE CLAIM IS: 1. An ignition means adapted to be located within the base of a case containing a propellant charge. the means comprising a housing with a base provided with a primer cap for ignition by external means (electrical or mechanical), a booster charge coupled with the primer within the housing, axial combustion ports through the top of the housing, and radial combustion ports through the housing wall in the region of the booster charge and communicating with a priming charge positioned around the housing.

2. An ignition means in accordance with Claim 1, wherein the radial combustion ports are aligned perpendicular to the longitudinal axis of the housing.

3. An ignition means in accordance with Claim 1, wherein the radial combustion channels are aligned obliquely to the longitudinal axis of the housing.

4. An ignition means according to any preceding claim, wherein the housing includes in axial alignment a first booster charge adiacent the primer cap and a second booster charge in contact with the first booster charge, the second booster charge lying adjacent both the axial and radial combustion ports.

5. An ignition means according to any preceding claim, wherein the housing containing the booster charge is screw connected with the base, the axial combustion ports being provided in a cap screw connected with the top of the housing.

6. In combination an ignition means according to any preceding claim and a casing housing a propellant charge, the ignition means being securable within an aperture in the base of the casing, with the radial combustion ports directed towards the priming charge adjacent the propellant charge.

7. The combination according to Claim 6, wherein the priming charge is annular and lies around the ignition means, the top of the ignition means being adjacent the propellant charge.

8. The combination according to Claim 6, wherein the priming charge is divided into a dise part between the top of the ignition means and the propellant charge and an annular part lying around the ignition means, the annular part of the priming charge being separate from the dise part.

9. An ignition means or a propellant charge casing incorporating same constructed and arranged to function substantially as herein described with reference to and as shown in Figure 1 or 2 of the accompanying drawings.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. surrounded by a bowl casing 10 of celluloid or other rapidly combustible substance. At the side of the booster charge 8 are a total of eight radial combustion ports 11, slanting towards the base ib, and provided through the wall of the housing 9. The second booster charge 8 has a sealing cap 12 provided with a total of four axial combustion ports 13. The propellant ignition means 1 is screwed into the base 14 of the shell or cartridge case 15 so that the sealing ring 3a and stop 3 forms a seal preventing any passage of gas from the ignition means to the cartridge case exterior. The base 14 of the cartridge case 15 is thick but only extends as far as the junction between the body la and the housing 9, so that the radial combustion ports 11 are left open. The space left within the case 15 and defined by the base 14, the side of the case 15 and the housing 9, is completely or partly filled by an annular priming charge bag 16, which is immediately adjacent the main propellant charge 17, which lies on the cover 12. The main charge consists of a powder package. As shown in Figure 2, the annular charge 16 may have a central disc like part 16a resting on the cover 12 with the remainder of the charge filling the space in the cartridge case 15. A particular advantage of this type of priming charge is that both the radial combustion ports 11 and the axial combustion ports 13 are in communication as far as ignition is concerned, with the priming charge. In the breech block 18 of the weapon the electrical striker pin 19 on firing moves forward towards the central contact 5, and the primer 6 is first ignited and subsequently the first booster charge 7 and thus the second booster charge 8 in succession. The eight combustion ports 11 serve to ensure that on combustion of the booster charges 7 and 8 the priming charge 16 is ignif8 starting generally from the base 14 of the cartridge case 15 to ensure that the charge will undergo uniform and complete com bastion propazatinz in the direction of the main charge 17 which burns in a way to ensure radix conversion of the pronellRnt charge 17 into the gas phase.The four axial combustion ports 13 and the eight radial combustion ports 11 combine with the priming charge 16 and 16a to ensure that the ignition chain in the charge is shorter with a reduction in ignition time variations. WHAT WE CLAIM IS:

1. An ignition means adapted to be located within the base of a case containing a propellant charge. the means comprising a housing with a base provided with a primer cap for ignition by external means (electrical or mechanical), a booster charge coupled with the primer within the housing, axial combustion ports through the top of the housing, and radial combustion ports through the housing wall in the region of the booster charge and communicating with a priming charge positioned around the housing.