GB2095374A - An impact or dentonation fuze for a projectile - Google Patents

Abstract

A fuze having a firing pin (9) includes a safety device in the form of a U-shaped clamp (17) having two limbs 17 joined by a permanently deformable web (23). The clamp 17 safeguards the firing pin (9) or percussion piece (8) connected to the pin (9), and is located between an intermediate part (10) and a housing (16). The webb (23) is permanently deformable when a projectile and fuze are spun, thereby rendering the clamp ineffective, after the projectile has been launched. <IMAGE>

Description

SPECIFICATION An impact or detonation fuze for a projectile This invention relates to an impact or detonation fuze for a projectile such as a gun shell, the fuze including a safety member or safety device which safeguards a striking member, for example, a firing pin and maintains the firing pin in a safe position when the projectile is introduced into the cartridge chamber of a weapon.

In a base fuze for an artillery shell, the firing pin has to be protected against the considerable acceleration which may occur when the projectile or shell with the fuze is introduced into the cartridge chamber of a weapon. Safety is also required during transportation of the projectile or shell fitted with the fuze. In addition, it is required that the safety device is rendered ineffective only when the projectile or shell is spun through a specific threshold spin. A safety device has been proposed in German Patent Specification No. 228652. Lamellae which are swingable as a result of centrifugal force safeguard the firing pin. It is a disadvantage of this prior proposed safety device, on account of confined space conditions, that it tends only to be suitable with large-calibre projectiles.With smaller projectile calibres of about 30 mm, the prior proposed safety device tends not to be suitable, on account of the confined space conditions and also because of the high production costs which wou Id be incurred.

A spin projectile fuze having a safety member in the form of a clamp which secures a detonator rotor in a safe position is shown in German Patent Specification No: 2539750. When a projectile which is provided with a fuze of this kind is launched, because of the spin effectthe clamp is permanently bent open and thereby frees the rotor for swinging a detonator into a live position i.e. in line with a firing pin.

An object of the present invention is to provide a relatively simple and inexpensive safety device on an impact or detonation fuze for a projectile.

According to the present invention there is provided a detonation fuze for a projectile such as a gun shell, comprising a striking member biassed to one end of a chamber and, in use, away from a detonator located between the fuze and an explosive charge, the striking member being restrained from activating said detonator by a safety member having two limbs straddling the striking member, the two limbs being connected to one another by a deformable arcuate web, the arrangement being such that the arcuate web is deformable as the fuze is spun so that, after launch of the projectile, the striking member is no longer restrained by the safety device from activating the detonator on impact of the projectile with a target.

Further according to the present invention there is provided a fuze assembly including a fuze as described in the immediately preceding paragraph and a rotor holding a detonator adjacent one end of the striking member and an explosive charge located adjacent said detonator opposed to the striking member.

Still further according to the present invention there is provided a combination of a projectile in the form of a shell to be launched from a cartridge chamber of a firearm, and a fuze assembly as described in the immediately preceding paragraph.

Still further according to the present invention there is provided a safety device, which is capable of being rendered ineffective by centrifugal force, for the striker of an impact fuze for a projectile which safeguards a firing pin of the fuze and, when the projectile containing the fuze is fed into the cartridge chamber of a weapon, holds the firing pin in a safe position, characterised in that the safety device is a clamp, the limbs of which safeguard the firing pin and support it in housing-fast manner and in that the limbs are connected to one another by an arcuate web which is permanently deformable by centrifugal forces.

In some embodiments of the present invention, the safety member or device may be integrally formed in a simple manner, for example, by punching the member out of sheet metal. The safety member or device may be of copper beryllium, and the limbs may grip the striking member at opposed locations. The safety member or device, advantageously, may be U-shaped in design and have recesses corresponding to or matching the firing pin.

By the present invention, upon launching of the projectile, relatively slight cross-sectional loads occur, so that a deformation of the clamp does not have to be feared.

In one embodiment ofthe present invention, the fuze comprises a first part releasably fastened to a second part shaped to seat a detonator, an intermediate part sandwiched between said first and second parts and the safety member being located between the intermediate part and the first part, the striking member extending from said chamber which is defined in said first part and through said intermediate part into said second part.

An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 shows a base fuze assembly in accordance with the invention; and Figure 2 shows a safety member in the form of a clamp of the fuze assembly shown in Figure 1.

Referring to the Figures, a base screw 1 is fastened or screwed to a fuze underpart 2. The fuze underpart 2 contains a rotor 3 with detonator 4 and a screw 5 with an explosive booster charge 6. Furthermore, a guide means including a safety sleeve 7 in the fuze underpart 2 is provided for safety before a projectile with the fuze assembly is introduced into a cartridge chamber or barrel. The base screw 1 houses a percussion piece or hammer 8, and a striking member in the form of a firing pin 9 is mounted therein. An intermediate piece 10 is screwed to the base screw 1.

The percussion piece 8 is supported by way of a spring 15 in a housing 16. Between the housing 16 and the intermediate piece 10 lies a safety member or device in the form of a low mass clamp 17 which safeguards the percussion piece 8 and is supported on the intermediate piece 10. The base screw 1 and housing 16 comprise a first part of the fuze and the underpart 2 comprises a second part.

As shown in Figure 2, the clamp 17 consists of limbs 19 and 20 having recesses 21,22, and an arcu ate web 23 connecting these limbs. The recesses 21, 22 correspond to the cross-section of a collar 18 of the firing pin 9.

Forces, arising as the result of a projectile shock or impact, on the percussion piece 8 and on the firing pin 9 act in the direction of the arrow A. The clamp 17 safeguards the percussion piece 8 and is supported againstthe intermediate piece 10 by housing 16. The clamp 47 straddles the firing pin 9 but may alterna- tively straddle the percussion piece 8 During the transmission of spin in the weapon barrel the projectile, and therewith the fuze, receive the required spin to render the safety device ineffective. As a result of the acceleration of the projectile, the clamp 17 is relieved, in the direction of the arrow A, from forces emanating from the percussion piece 8 and can therefore expand in radial directions B, the web 23 being permanently deformed. The radially expanded clamp 17 then butts against wall 25 of recess 26.

Upon impact of the projectile on a target, the percussion piece 8, by way of collar 18, axially moves the firing pin 9, which then punctures the detonator 4 arranged by the rotor 3 in the live position.

Claims (16)

1. A detonation fuze for a projectile such as a gun shell, comprising a striking member biassed to one end of a chamber and, in use, away from a detonator located between the fuze and an explosive charge, the striking member being restrained from activating said detonator by a safety member having two limbs straddling the striking member, the two limbs being connected to one another by a deformable arcuate web, the arrangement being such that the arcuate web is deformable as the fuze is spun so that, after launch of the projectile, the striking member is no longer restrained by the safety device from activating the detonator on impact of the projectile with a target.

2. Afuze as claimed in Claim 1 in which the safety member is integrally formed and the limbs grip the striking member at opposed locations.

3. A fuze as claimed in Claim 2 in which the safety member is generally U-shaped and the limbs have recesses matching the shape of the striking member.

4. A fuze as claimed in Claim 2 or Claim 3 in which the striking member is a firing pin and the limbs engage a collar of the firing pin.

5. Afuze as claimed in any one of Claims 1 to 4 in which the safety member is of copper.

6. Afuze as claimed in any one of Claims 1 to 5 comprising a first part releasably fastened to a second part shaped to seat a detonator, an intermediate part sandwiched between said first and second parts and the safety member being located between an intermediate part and the first part, the striking member extending from said chamber which is defined in said first part and through said intermediate part into said second part.

7. Afuze as claimed in Claim 6 comprising guide means for the striking member between the second and intermediate parts.

8. Adetonation fuze substantially as herein described with reference to the accompanying draw ings.

9. Afuze as claimed in Claim 1 in which the safety member is substantially as herein described with reference to Figure 2 of the accompanying drawings.

10. A fuze assembly including a fuze as claimed in any one of the preceding claims and a rotor holding a detonator adjacent one end of the striking menlber, and an explosive charge located adjacent said detonator opposed to the striking member.

11. An assembly as claimed in Claim 10 and substantially as herein described with reference to the accompanying drawings.

12. A combination of a projectile in the form of a shell to be launched from a cartridge chamber of a firearm, and a fuze assembly as claimed in Claim 10 or11.

13. A combination as claimed in Claim 12 in which the shell has a calibre of about 3 cm.

14. A safety device, which is capable of being rendered ineffective by centrifugal force, for the striker of an impact fuze for a projectile which safeguards a firing pin of the fuze and, when the projectile containing the fuze is fed into the cartridge chamber of a weapon, holds the firing pin in a safe position, characterized in that the safety device is a clamp, the limbs of which safeguard the firing pin and support it in housing-fast manner and in that the limbs are connected to one another by an arcuate web which is permanently deformable by centrifugal forces.

15. A safety device as claimed in Claim 14, characterised in that the clamp is U-shaped and has recesses corresponding to the firing pin.

16. A safety device as claimed in Claim 15, characterised in that the clamp consists of copper beryllium.