Method and arrangement for modifying a separable projectile

A method for modifying a separable projectile between a test embodiment or an effect embodiment includes detaching the front projectile body from the rear projectile body, arranging a payload container in the front projectile body where the payload container comprises measuring equipment or an effect part, and fitting the front projectile body to the rear projectile body by way of a belt. A separable projectile which can be modified between a test embodiment and an effect embodiment is also provided.

BACKGROUND AND SUMMARY

The present invention relates to a method and an arrangement for modifying a separable projectile.

Separable projectile designs for the separation of one or more effect charges in the forward direction of the projectile are disclosed by the following patent documents: U.S. Pat. No. 4,333,400A US Navy 1980, U.S. Pat. No. 3,839,962 US Army 1973 and U.S. Pat. No. 3,513,777 US Army 1968, among others.

In the testing of a separable projectile as described above various types of measuring equipment are normally used in the projectile for registering parameters such as acceleration stresses, velocity, pressure etc., during the launch phase and trajectory phase of the projectile. Recovery of the measuring equipment after testing for evaluation of the measurement data is done, for example, by slowing a projectile in compacted bales backed by a sand trap. The method has proved less suitable, however, for certain types of sensitive measuring equipment.

A need therefore exists for a separable projectile arranged in a test embodiment, comprising a recoverable measuring equipment for measuring characteristics of the projectile during the acceleration and trajectory phase without damaging the measuring equipment after testing.

It is also desirable that said separable projectile should be easy to modify from a test embodiment for testing out the projectile to an effect embodiment for terminal effect.

It is desirable to provide a separable projectile arranged in a test embodiment for measuring characteristics of the projectile during the acceleration and trajectory phase of the projectile without ensuing damage to the measuring equipment.

It is also desirable to provide a method for modifying a separable projectile in that the projectile can easily be modified from a test embodiment to an effect embodiment; which means that the projectile is produced in an unmodified state. The payload container, adapted for holding the measuring equipment or the effect charge, is produced and supplied separately. This affords flexibility in modifying said projectile to the desired form, that is to say the test embodiment or the effect embodiment.

According to an aspect of the present invention, a method has been provided for modifying a separable projectile from a test embodiment to an effect embodiment and vice versa, the projectile comprising a payload container and a separation charge arranged behind the payload container for separating the payload container from the projectile in the forward direction of the projectile.

A characteristic feature of the method is that the projectile is modified from the test embodiment to the effect embodiment in that the payload container is changed from a payload container comprising measuring equipment to a payload container comprising an effect part by:

detaching the front projectile body from the rear projectile body,

arranging a payload container in the front projectile body where the payload container comprises measuring equipment or at least one effect part, and

fitting the front projectile body to the rear projectile body by way of a belt.

According to the present invention a separable projectile has also been provided, comprising a payload container and a separation charge arranged behind the payload container for separating the payload container from the projectile in the forward direction of the projectile, the projectile being modifiable from a test embodiment to an effect embodiment by changing the payload container.

According to a second embodiment of the separable projectile the separation charge consists of or comprises a propellant charge comprising a smokeless nitrocellulose propellant.

According to a third embodiment of the separable projectile the projectile comprises a pyrotechnic primer charge for initiating the propellant charge.

According to a fourth embodiment of the separable projectile the projectile comprises a fuse for initiating the pyrotechnic primer charge.

According to a fifth embodiment of the projectile in a test embodiment the payload container comprises a measuring equipment for measuring the acceleration stresses, velocity, altitude, temperature etc. of the projectile during the acceleration and trajectory phase of the projectile.

According to a sixth embodiment of the projectile in the test embodiment the payload container is connected to a parachute for recovery of the payload container after separation from the projectile.

According to a seventh embodiment of the projectile in the effect embodiment the payload container consists of or comprises an integral unit, entirely or partially closed.

According to an eighth embodiment of the projectile in the test embodiment the parachute is arranged and packed in a separable parachute container on or in the rear part of the payload container.

According to a ninth embodiment of the projectile in the effect embodiment the payload container comprises at least one effect part comprising at least one effect projectile and at least one explosive charge for aimed effect against a target.

According to a tenth embodiment of the projectile in an effect embodiment the payload container comprises a delay charge for delayed initiation of said effect part.

According to an eleventh embodiment of the projectile in an effect embodiment the payload container is capable of separating into two or more parts after separation for release of the effect part.

According to a twelfth embodiment of the projectile in an effect embodiment the projectile comprises a fuse for initiating the pyrotechnic primer charge and the pyrotechnic delay charge.

The invention, according to an aspect thereof, affords a series of advantages and effects, the most important of which are:

Modification of the separable projectile from a test embodiment to an effect embodiment by changing the payload container affords a simplified and cost-effective method in which the projectile can be drawn directly from one and the same production line irrespective of the form of embodiment.

The separation of a payload container, comprising one or more effect charges, in the forward direction of the projectile prevents potentially disruptive action from the projectile body on the effect charge during the effect phase of the projectile.

The separation of a payload container, comprising a measuring equipment and a parachute, in the forward direction of the projectile allows recovery of the measuring equipment without damage occurring to the measuring equipment.

DETAILED DESCRIPTION

The invention, according to an aspect thereof, relates to a method for modifying a separable projectile from a test embodiment to an effect embodiment or vice versa.

The basic construction of the projectile is such that the projectile can easily be modified from the test embodiment to the effect embodiment by changing the payload container. In a test embodiment the payload container is characterized in that that it comprises sensitive measuring equipment for measuring characteristics of the projectile during the launch and trajectory phase of the projectile. The payload container is also connected to a parachute for recovery of the payload container after separation from the projectile. In the effect embodiment the payload container is characterized in that it comprises an effect part comprising one or more effect projectiles and effect charges for effect against a target after separation of the payload container.

The content of the payload container differs, therefore, depending on the embodiment of the projectile. In order to fit the payload space of the projectile regardless of the embodied form of the projectile, the payload containers are of similarly shaped design, preferably cylindrical, and of the same size.

The payload containers differ, however, with regard to their construction. In an effect embodiment the payload container preferably comprises a longitudinally dividable cylinder, comprising two cylinder halves fixed to one another so that the payload container, after separation from the projectile, divides into two halves for release of the effect part in the forward direction of the projectile. In a test embodiment the payload container consists of or comprises an integral unit which does not divide after separation, entirely or partially closed, for safe preservation of the measuring equipment during the course of testing. In a special embodiment, not shown, the cylindrical payload container comprises a rear cylindrical cavity for the connection of a parachute or a container holding a parachute.

In said test embodiment the payload container is connected to a parachute for recovery of the payload container after separation from the projectile.

The parachute, preferably packed in a separate, detachable parachute container, is arranged in or adjacent to the rear end of the payload container, preferably in the cylindrical cavity. The parachute container is preferably designed as a separable cylindrical module detachably fitted adjacent to or in the rear cylindrical part of the payload container, for example by snap fasteners.

FIG. 1shows the separable projectile1in an effect embodiment for effect in the forward direction of the projectile1. The projectile1comprises a front projectile body2and a rear projectile body3joined by a belt4, the belt4joining the rear projectile body to the front projectile body by means of a threaded connection, shrink connection and/or press-fit connection, for example.

The rear projectile body3comprises a separation charge5and a pyrotechnic primer device6for initiating the separation charge5. The primer device6is arranged in front of the separation charge5behind a drive plate7adjacent to the rear end of a payload container8and the front projectile body2. The separation charge5preferably consists of or comprises a propellant charge of conventional type, for example a propellant charge comprising a smokeless nitrocellulose propellant, or in an alternative embodiment a composite propellant.

The payload container8which is arranged in the front projectile body2and comprises at least one effect part9comprising one or more effect projectiles41and effect (explosive) charges42together with one or more delay charges43for delayed initiation of said minimum of one effect part9. A proximity fuse40comprising an activation unit for activating the primer device6, is arranged in the nose part10of the front projectile body2, in front of the payload container8. The nose part10is fitted to the front projectile body2by a second drive plate11and by shear pins30, which are designed to rupture under the effect of the pressure on the separation of the payload container8from the projectile1. In an alternative embodiment a continuous detonator wire12, preferably a nonel, is arranged between the pyrotechnic primer device6and the second drive plate11for separating the nose part10from the projectile1.

FIG. 2shows the separable projectile20in a test embodiment for testing the projectile20. In the test embodiment the payload container21comprises e measuring equipment50for registering acceleration stresses on the payload container during the launch phase and the velocity, altitude and temperature during the trajectory phase. In the test embodiment the projectile20differs in that it has no firing connection between the primer device6and the payload container21, since there is no effect part9and no delay charges. Otherwise the projectile20in the test embodiment is identical to the projectile1in the effect embodiment.

The payload container21in the test embodiment is designed as a strong, integral unit, entirely or partially closed, intended to remain intact and not to disintegrate or break up after separation from the projectile. The payload container21with measuring equipment50may also be connected/coupled to a parachute22by parachute lines23connected to the payload container21via a ball bearing-guided pivot24on the rear end of the payload container21. The parachute22is packed and arranged in a separable parachute container25of its own arranged behind or inside the payload container21, preferably in a cylindrical space in the rear part of the payload container21.

After separation of the payload container21and of the parachute container25from the projectile20, the parachute container25is broken up into smaller parts at the same time that the parachute22is released and deploys, so that the payload container21with measuring equipment50slowly falls to the ground without the measuring equipment being damaged.

In an alternative embodiment, not shown, the effect part9of the projectile1in the effect embodiment of the projectile1is arranged in a payload container of the same type as that used for the measuring equipment in the test embodiment of the projectile20, that is to a payload container that does not break up after separation from the projectile and which comprises a separable parachute container25with parachute22. The payload container differs, however, in that its front end is open for releasing the effect part9when the payload container approaches a target.

The invention is not limited to the embodiments shown but may be modified in various ways without departing from the scope of the patent claims.