GB2237362A

GB2237362A - Projectile retardation system

Info

Publication number: GB2237362A
Application number: GB8923931A
Authority: GB
Inventors: Glenn Edward Martin Webb
Original assignee: British Aerospace PLC
Current assignee: BAE Systems PLC
Priority date: 1989-10-24
Filing date: 1989-10-24
Publication date: 1991-05-01
Anticipated expiration: 2009-10-24
Also published as: GB2237362B; GB8923931D0

Abstract

A retardation system for use on a projectile launched from an aircraft absorbs the retardation forces, with minimal inertial loss, arms the fuze and erects the fins. A parachute or balloon is attached via lines 3 to an arming cylinder 4, the force on the lines causing the cylinder to slide rearwardly relative to the projectile. This movement causes (i) portion 7 of the cylinder 4 to compress a damper 8 via an arm 10, thus damping launch forces; (ii) lines 16 to erect the fins; and (iii) a ballscrew 11 and a shaft 14 to be screwed into a position to arm the fuze. <IMAGE>

Description

Fin Erection Retardation and Arming Mechanism This invention relates to a mechanism for fin erection, fuze arming and retardation of projectile.

High speed aircraft and the like may view hostile targets as they fly over enemy territory. The aircraft then aim to launch a missile to destroy that target. In order that the aircraft is not put at risk and that say a guided missile can follow a required trajectory the missile is generally retarded immediately after launch. This retardation may be achieved by the use of parachutes and) our balloons, released after a set time. This can cause problems since the launching aircraft velocity is not taken into consideration, as a result it may not, for example, be out of risk when the missile is detonated.

For safety and other reasons it is also essential that both fin erection and fuze arming are achieved reliably. There are many and various methods and mechanisms of achieving this, each of which may have problems associated therewith.

The object of this invention is to provide a mechanism that at least overcomes some of the problems encountered in the other fin erection and fuze arming mechanisms and which provides a means of retarding the missile which is velocity depending.

A cording to one aspect of the present invention there is provided a projectile retardation system for use in a projectile launched form an aircraft in which said system includes: a retardation means; and a damper for absorbing the forces on the projectile generated by the retardation means, such as to inhibit inertial losses of the launched projectile.

Reference will now be made by way of example to the accompanying drawing in which single figure is a simplified cross-sectional diagram of a rear section of a projectile according to one embodiment of the invention.

A missile the rear portion of which is shown generally at 1, is launched from an aircraft (not shown). On launch a parachute (also not shown) is released from the rear of the projectile Z. The parachute is attached to the missile by parachute lines 3. The parachute lines are attached, specifically, to a generally cylindrical arming cylinder 4. The arming cylinder comprises two substantially tubular section 5 and 6 separated by a solid dividing member 7 and is movable along an axis parallel to the length of the missile. Within section 5 is located a damper 8 which is firmly connected (not shown) to the rear casting 9 and an arm 10 which extends out of the damper and up to the dividing member. The connection of the damper to the rear casting member is permitted by the presence of slots (not shown) running the length of the arming cylinder.

Section 6 houses a ball screw 11 and a ball nut 12. The ball nut is threaded onto the ball screw, and is further firmly attached to the arming cylinder 4. The ball screw is attached at its end 13 to a fuze arming shaft 14 of the type of fuze which needs fro example the detonator screwed down a number of turns in order the initiate detonation.

When the missile is launched from the aircraft, the parachute is ejected, as it unfolds a force is generated on the lines 3 in the general direction of arrow A. This forces causes a number of things happen. As the arming cylinder slides towards the back of the missile.

The dividing member 7 presses against the arm, thereby compressing into the damper. This has the effect damping the effect of the launching forces on the body of the missile as a whole. The compression of the damper caters for varying launch speeds, such that the separation between the aircraft and the missile is constant thereby giving a minimum inertia loss for all launch speeds since the damper not the missile absorbs the parachute retardation forces.

The foremost end of the arming cylinder 15 is attached to lines 16 (only two of which are shown) which in turn are attached to the fin erecting mechanisms. The force on the cylinder which causes it to slide backwards also pulls the fins into place. The damper further prevents any jamming of this action, so that fin erection is reliably achieved.

Another effect of the movement of the arming cylinder is that it causes the ball screw and subsequently the fuze arming shaft to screw up against the fuze, since the ball nut is held relative to cylinder 4.

The damper will generally be of the oil filled type, however the system could be adapted to suit any variation of damper.

There may be as many lines 16 as there are fins, and of course any number of fins. Alternatively they may be one line which produces erection of all the fins.

The damper orifice may be variable such that differing environmental and other requirement may be considered prior to launch.

The system is applicable t9 any retardation system requiring controllable andl or minimum inertia loss. For example when a Torpedo is released from an aircraft. Alternatively for use as a mine deployment retarded system, scattering the mines over a site by varying the dampers for their orifices to produce differing trajectories.

It should be noted that the parachute may be replaced by any known alternative retardation device, for example a balloon.

As the arming cylinder is dragged backwards is the parachute forces at a certain predetermined point, ie for example at a point when fin erection, fuze arming and retardation are complete, the parachute is released along with release 17. This release can be achieved in any manner known in the art.

Claims

1. A projectile retardation system for use in a projectile launched from an aircraft in which the system includes: a retardation means; and a damper for absorbing the forces on the projectile generated by the retardation means, such as to inhibit the inertial losses of the launched projectile.

2. A retardation system according to claim 1 which further includes means for utilising said forces to arm a fuze within the projectile.

3. A retardation system according claim 1 and claim 2 which further includes means for utilising said forces for erecting one or more fins on the projectile.

4. A retardation system according to any one of claims 1,2 or 3, where in said retardation means is a parachute attached to the missile.

5. A retardation system substantially as herein before described, with reference to, and as illustrated in, the accompanying drawings.