GB1593563A

GB1593563A - Devices for effecting auto-destruction of gyratory missiles

Info

Publication number: GB1593563A
Application number: GB1669/78A
Authority: GB
Original assignee: Manufacture de Machines du Haut Rhin SA MANURHIN
Current assignee: Manufacture de Machines du Haut Rhin SA MANURHIN
Priority date: 1977-02-04
Filing date: 1978-01-16
Publication date: 1981-07-22
Also published as: SE7712310L; IT1092087B; CH635671A5; BE860304A; SE422368B; DE2755712A1; FR2379796B1; ES464643A1; NL7714411A; DE7738138U1; DE2755712C2; IT7819547A0; FR2379796A1

Abstract

The self-destruction device for spinning projectiles has a blocking part (14) and a release part (24) which, constructed in the form of a bracket, grip a spring-loaded firing pin (20) and can pivot about a common shaft (12). Their centres of gravity (G1, G2) are located, for example, in the quiescent state in such a position that the blocking part (14) blocks the firing pin (20). The releasing part (24), which is subject to the force of a spring (26), is pivoted with a stop surface (30) in the direction of a cam (32) on the blocking part (14) when the centrifugal force reduces after the spinning projectile has been fired, so that the blocking part (14) is driven and the centres of gravity (G1, G2) are displaced. At the same time, the firing pin (20) is released. The firing pin (20) is provided with a flange (18) by means of which it can be locked in the prestressed position by means of the blocking part (14). <IMAGE>

Description

(54) DEVICES FOR EFFECTING AUTO-DESTRUCTION OF GYRATORY MISSILES (71) We, MANUFACTURE DE MACHINES DU HAUT-RHIN S.A., a French Company, of 10 rue de Soultz, 68060 Mulhouse Cedex, France, 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: The invention refers to a mechanical device for effecting auto-destruction of a gyratory missile.

Devices of this kind are known which have the aim of setting off the automatic destruction of a missile which has not reached its target and is finishing its ballistic path at a great distance from the firing point.

These devices operate owing to the fact that the missiles are launched with a certain speed of rotation about their longitudinal axes and that this rotation diminishes rapidly when the missile arrives at the end of its path with a low residual forwards velocity. The reduction of the centrifugal forces generated by the speed of rotation is employed for setting off the auto-destruction.

In the known devices of this kind, centrifugal forces are exerted on movable parts equipped with catch surfaces which tend to keep these surfaces engaged in a position where they block the operation of a member for setting off the self-destruction (for example, they block the movement of a firing-pin).

A spring acts to oppose these centrifugal forces and ends by overcoming them when the diminish, thus freeing the catch surfaces and allowing the operation of the member for setting off auto-destruction.

The disadvantage of these devices is that the instant of release and hence of autodestruction depends heavily upon the shape and the condition of the catch surfaces which must be able to hold back parts against high forces whilst allowing accurate and reliable release at the opportune moment.

It is the object of the present invention to reduce or eliminate this disadvantge.

According to the present invention, there is provided a device for effecting autodestruction of a gyratory missile, comprising a movable contact member for setting off auto-destruction which member is neutralizable by being rendered immovable and is capable of bein freed in order to set off destruction of the missile, characterised by the fact that the device comprises a first part (hereafter termed "sear") movable about an axis spaced from the gyratory axis of the missile and locatable in a position of neutralization where it renders the contact member immovable, the sear being constructed and arranged so that centrifugal forces acting thereon due to gyration of the missile tend to keep it in that position while the missile gyrates at more than a predetermined rate, a second part (hereafter termed "trigger") movable about the same axis as the sear and constructed and initially located in a first position where its centre of gravity is in a region such that the centrifugal forces tend to drive it in the same direction as the sear, a spring for acting upon the trigger against the centrifugal force exerted there upon when it is in its first position and adapted to overcome such force when the rate of gyration of the missile falls below said predetermined rate, the sear and trigger exhibiting abutment surfaces which are arranged to cooperate with one another when the trigger has shifted sufficiently under the action of the spring, and the sear and trigger being arranged in such a way that when the trigger comes into abutment against the sear, the resultant centre of gravity of the two parts is located in a region where the centrifugal forces tend to move the sear and trigger together away from their original position whereby the contact member is freed.

The device of the present invention employs the movement of a trigger and sear in order that in a first state (inhibition of the auto-destruction) the two parts are driven by the centrifugal force towards a position where the sear renders immovable the contact member, whilst in a second state the centre of gravity of at least the sear is at a position where the centrifugal force drives it in the reverse direction towards a position of freedom for the contact member. The final position of the centre of gravity of the sear results from the displacement of the trigger which is subjected to the action of a spring which tends to separate it from its original position against the centrifugal force and ends in succeeding in doing it when the centrifugal force has diminished sufficiently.

The trigger then preferably arrives in a second position where centre of gravity lies in a position such that centrifugal forces acting on it augment the action of the spring. Hence the sear and trigger are initially thrust in the direction of engagement with the movable contact member, and then, when the rate of gyration drops below the predetermined level, are thrust back into the release or auto-destruction position by the centrifugal forces acting on them. The predetermined rate of gyration at which this change of state takes place can be set by selecting a spring of suitable strength.

The contact member preferably consists of a firing-pin which can move in the direction of the axis of rotation of the missile but which is held back by a detent flange under which the bottom of the stirrup constituting the sear comes to be engaged when the latter is in its neutralization position, that is to say, either during storage of the missile or whilst it is revolving at normal speed.

The firing-pin is freed when the missile ceases to revolve at a sufficient speed and the reduction in centrifugal force allow the trigger to be moved by the spring and this in turn moves the sear until the latter is released from under the flange on the firing-pin.

Other characteristics and advantages of the invention will appear upon reading the detailed description which follows and which is given with reference to the attached drawings in which: Figure 1 represents a plan of the autodestruction device in accordance with the invention, in the storage position; Figure 2 shows a lateral section of the auto-destruction device; Figure 3 shows a plan of the autodestruction device in the position of normal motion during the course of the ballistic path of a gyratory missile which is carrying it; Figure 4 shows a plan of the autodestruction device in a transitory position when the speed of rotation of the gyratory missile has diminished sufficiently; and Figure 5 shows a plan of the selfdestruction device in the self-destruction position.

The device in accordance with the invention, mounted in a missile which is not shown, is shown diagrammatically in Figure 1 in plan and in Figure 2 which shows a lateral section of it in the directon X'X as Figure 1.

The device is contained in a casing 10 which bears a fixed spindle of rotation 12 off-centred with respect to an axis of gyration O of the missile.

A movable sear 14 in the shape of a stirrup is mounted on a spindle 12. The sear 14 has two arms 15 and 17 and it is by the end of the arm 15 that it is mounted on the spindle 12.

In the normal position (that is to say, either when the missile is stored or when it is revolving at normal speed during the course of its ballistic trajectory), the sear 14 reaches round the axis of gyration 0 of the missile and the design of this part is chosen so that if the bottom 16 (between the arms 15 and 17) of the stirrup 14 is located at one side of the line X'X joining the axis 0 and the spindle 12, then the centre of gravity G1 of the part 14 is in spite of that located on the other side of the line XX (whilst remaining all the same close to this line).

The bottom 16 connecting the arms 15 and 17 of the stirrup constituting the sear 14 is circular and adapted for coming to engage under a detent flange 18 on a firing-pin 20 which is used for setting off the autodestruction of the missile. The firing-pin 20 is capable of moving along the axis of the missile under the thrust of a compressed spring 22 (Figure 2), but it is rendered immovable at discharge in order to prevent autodestruction, by the sear 14 which engages under the detent 18.

In order to set off the self-destruction it will be sufficient if the sear 14 turns about the spindle 12 sufficiently to disengage from under the flange.

A second movable part 24 which will hereafter be referred to as the trigger is likewise mounted on the spindle 12. It too has the shape of a stirrup and it is the end of one of the arms of this stirrup which is mounted on the spindle 12.

The trigger 24 is wholly superimposed upon the sear 14, it is turned on the same side and its centre of gravity G2 lies when the missile is stored or when it is revolving at normal speed, at the same side of the line X'X as that of the sear 14. In this way the centrifugal force tends to bring the bottoms of the sear 14 and trigger 24 closer to the axis of gyration of the missile.

The trigger 24 is recalled by a spiral spring 26 which tends on the contrary to separate the bottom of the trigger 24 from the axis of gyration 0, hence initially opposing the centrifugal force being exerted on this trigger 24.

The spring 26 bears on one side against the casing 10 of the device and on the other against a lug 28 on the trigger 24.

The trigger 24 exhibits an abutment surface 30 capable of coming against a lug 32 which projects from the sear 14 at a pont located on the path of the abutment surface 30 in rotation and to a height sufficient to be able to catch it. The trigger 24 will thus be able in turning under the action of the spring 26 to come into abutment against the lug on the sear 14 and the trigger and sear will then move together.

Finally it is provided that in the storage position the sear and trigger parts 14 and 24 are locked in such a way that their centres of gravity G1 and G2 are located on the right side of the line X'X, that is to say, on the side such that at discharge of the missile the centrifugal force brings the sear 14 and trigger 24 nearer to the axis of gyration 0 of the missile, the former hence blocking any movement of the firing-pin 20 before discharge of the missile and continuing to block it afterwards because of this centrifugal force on the first part.

Figure 1 represents just the selfdestricution device in its storage position where it is neutralized by a latch 34 which consists of a blade wedged between a groove 36 in the casing and a notch 38 formed at the back of the sear 14 and trigger 24 which are thus kept applied in their position of neutralization of the setting-off of the selfdestruction (firing-pin 20 rendered immovable by its flange 18 and centres of gravity of the sear 14 and trigger 24 above the line X'X). The latch 34 retains the second trigger 24 in particular in this position against the restoring force of the spring 26.

The operation of the device is shown diagrammatically in Figures 3 to 5.

In Figure 3 the state of the device is seen when the missile has been launched and it is revolving at normal speed.

The centrifugal force tends to bring the trigger part 24 closer to the axis of rotation 0 of the missile. In fact it was said that the trigger 24 at discharge was wedged in a storage position such that its centre of gravity G2 is on the other side of the line X'X with respect to the bottom of the sirrup constituting the trigger 24.

The trigger 24 comes to a stop against the wall of the casing 10 of the device (or against the firing-pin, for example) and the latch 34 is freed since it is no longer wedged by the trigger 24 in its original position; latch 34 disengages completely and comes and flattens itself against the wall of the casing under the effect of the centrifugal force as seen in Figure 3.

The centrifugal force likewise keeps the sear 14 under the detent flange 18 of the firing-pin 20 since its centre of gravity G1 is also located at discharge on the other side of the line X'X with respect to the bottom of the stirrup constituting the sear 14.

As long as the missile revolves sufficiently fast this arrangement as Figure 3 is maintained and the firing-pin cannot free itself.

In Figure 4 the auto-destruction device is seen in a transitory state when the speed of rotation of the missile has sufficiently diminished for the force of the return spring 26 acting upon the trigger 24 to become greater than the centrifugal force on the trigger and to make it move away from the centre of gyration of the device.

As the latch 34 has disengaged from its storage position upon discharge of the missile, there is no longer anything opposing the trigger 24 from moving away appreciably from the centre of gyration 0 when the centrifugal force diminishes.

In proportion as this shifting of the trigger 24 is produced, the centre of gravity G2 comes back towards the line X'X and ends by passing to the other side. This abruptly brings about an acceleration of the motion of the trigger 24 because the centrifugal force is then added to the action of the return spring 26 for moving the bottom of the trigger 24 away from the axis of gyration 0 of the missile.

The abutment surface 30 of the trigger 24 then comes into contact with the lug 32 on the sear 14.

The abutment surface 30 and the lug 32 are arranged so that the contact between these two portions is effected at a time when the position of the centre of gravity G2 is sufficiently below the line X'X (the centre of gravity G1 having itself remained above the line X 'X) so that the resultant centre of gravity of the sear and trigger 14 and 24 (which are made to move together by the coming into contact of the surfaces 30 and the lug 32) lies below the line X'X at the time othis contact.

Thus once contact is effected between the sear 14 and the trigger 24 these two parts behave as an integral whole and the centrifugal force drives them both in a direction which tends to withdraw the sear 14 from under the detent flange 18 of the firing-pin 20 until complete disengagement of the sear 14 brings about the freedom of the firing-pin.

This is represented in Figure 5 which shows the phase of auto-destruction.

The two parts are first of all driven together by the action of the centrifugal force upon their resultant centre of gravity. Then the movement of the sear 14 brings about the passing of its centre of gravity G1 likewise from the other side of the line X'X, which enables the motion of disengagement of the sear 14 from the detent flange 18 to be completed even if-the two parts cease to move together, for example, in the case of Figure 5 where the trigger 24 has come to a stop againt the casing of the device before the sear 14 has finished its motion of complete withdrawal.

Auto-destruction is clear for a number of reasons.

Firstly, the motion of the trigger 24 is effected with the addition of the forces of recall of the spring 26 and of the centrifugal force on this part as soon as its centre of gravity has passed across from the other side of the line X'X. Next, the trigger 24 comes to strike against the lug 32 on the sear 14 only when the resultant centre of gravity of the two parts taken together lies underneath the line X'X. Finally the trigger 24 comes and strikes the lug 32 on the sear 14 with a certain speed of impact which favours rapid disengagement of the sear 14 from under the detent flange on the firing-pin.

Starting from the time when the resultant of the centrifugal force applied to the trigger 24 is cancelled by the movement of the centre of gravity G2 from its original position to a new position on the axis X'X the force from the return spring (26) becomes preponderant, and after the crossing of G2 from the other side of the axis X'X the centrifugal force applied to the trigger (24) goes on increasing and is added to the residual force of recall of the spring 26 so that the trigger 24 is then animated with an accelerated motion.

WHAT WE CLAIM IS: 1. A device for effecting autodestruction of a gyratory missile, comprising a movable contact member for setting off auto-destruction which member is neutralizable by being rendered immovable and capable of being freed in order to set off destruction of the missle, characterised by the fact that the device comprises::-a first part (hereafter termed "sear") movable about an axis spaced from the gyratory axis of the missile and locatable in a position of neutralization where it reders the contact member immovable, the sear being constructed and arranged so that centrifugal forces acting thereon due to gyration of the missile tend to keep it in that position while the missile gyrates at more than a predetermined rate, a second part (hereafter termed "trigger") movable about the same axis as the sear and constructed and initially located in a first position where its centre of gravity is in a region such that the centrifugal forces tend to drive it in the same direction as the sear-a spring for acting upon the trigger against the centrifugal force exerted there upon when it is in its first position, and adapted to overcome such force when the rate of gyration of the missile falls below said predetermined rate,- the sear and trigger exhibiting abutment surfaces which are arranged to cooperate with one another when the trigger has shifted sufficiently under the action of the spring, and the sear and trigger being arranged in such a way that when the trigger comes into abutment against the sear, the resultant centre of gravity of the two parts is located in a region where the centrifugal forces tend to move the sear and trigger together away from their original position whereby the contact member is freed.

2. A device as in Claim 1, characterised by the fact that the sear and trigger each have a stirrup shape, the common axis of these parts being at one end of one arm of each of the stirrups.

3. A device as in Claim 2, characterised by the fact that the stirrups are turned in the same direction and generally superimposed upon one another.

4. A device as in Claim 3, characterised by the fact that the contact member consists of a firing-pin capable of moving in the direction of the axis of gyration of the missile and equipped with a detent for engagement by the sear when the latter is in its position of neutralization.

5. A device as in one of the Claims 1 to 4, characterised by the fact that when the missile is gyrating at a rate above said predetermined rate the centres of gravity of the sear and trigger are on one and the same side of the line joining the axis of gyration of the missile and the common axis of the two parts.

6. A device as in Claim 5, characterised by the fact that the abutment surfaces of the sear and trigger are located on these parts in positions such that they come into contact with one another under the effect of the decrease in the centrifugal force only when the centre of gravity of the trigger has crossed over from the other side of the said line.

7. A device as in one of the Claims 1 to 6, characterised by the fact that the spring is a spiral spring mounted round the common axis of the sear and trigger and bearing against the casing of the device.

8. A device for effecting autodestruction of a gyratory missile substantially as herein described with reference to the accompanying drawings.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. strike against the lug 32 on the sear 14 only when the resultant centre of gravity of the two parts taken together lies underneath the line X'X. Finally the trigger 24 comes and strikes the lug 32 on the sear 14 with a certain speed of impact which favours rapid disengagement of the sear 14 from under the detent flange on the firing-pin. Starting from the time when the resultant of the centrifugal force applied to the trigger 24 is cancelled by the movement of the centre of gravity G2 from its original position to a new position on the axis X'X the force from the return spring (26) becomes preponderant, and after the crossing of G2 from the other side of the axis X'X the centrifugal force applied to the trigger (24) goes on increasing and is added to the residual force of recall of the spring 26 so that the trigger 24 is then animated with an accelerated motion. WHAT WE CLAIM IS:

1. A device for effecting autodestruction of a gyratory missile, comprising a movable contact member for setting off auto-destruction which member is neutralizable by being rendered immovable and capable of being freed in order to set off destruction of the missle, characterised by the fact that the device comprises::-a first part (hereafter termed "sear") movable about an axis spaced from the gyratory axis of the missile and locatable in a position of neutralization where it reders the contact member immovable, the sear being constructed and arranged so that centrifugal forces acting thereon due to gyration of the missile tend to keep it in that position while the missile gyrates at more than a predetermined rate, a second part (hereafter termed "trigger") movable about the same axis as the sear and constructed and initially located in a first position where its centre of gravity is in a region such that the centrifugal forces tend to drive it in the same direction as the sear-a spring for acting upon the trigger against the centrifugal force exerted there upon when it is in its first position, and adapted to overcome such force when the rate of gyration of the missile falls below said predetermined rate,- the sear and trigger exhibiting abutment surfaces which are arranged to cooperate with one another when the trigger has shifted sufficiently under the action of the spring, and the sear and trigger being arranged in such a way that when the trigger comes into abutment against the sear, the resultant centre of gravity of the two parts is located in a region where the centrifugal forces tend to move the sear and trigger together away from their original position whereby the contact member is freed.