Bofors Defence Ab

Bae Systems Bofors Ab

Bofors Defence Aktiebolag

Ulf Holmqvist

Ulf Hellman

Stig Johnsson

This disclosure relates to a method and an arrangement for low or non-rotating artillery shells fired from launch weaponry, and which introduces a portion of the barrel pressure built up in the barrel during the launch phase into a chamber arranged in the low or non-rotating artillery shell which is delimited in at least one direction by an element which is movable relative to the rest of the shell when a differential pressure between the chamber and the external environment of the shell is sufficient to move the element. The moveable element may be a protective casing covering fins of the artillery shell.

Method and arrangement for low or non-rotating artillery shells

The present invention relates to a fin-stabilized artillery shell () comprising a body part () which can be axially displaced rearwards, in the direction of flight of the shell, once the latter has left the barrel from which it has been fired, and which in the original position is fully retracted in the shell (), and in which a number of deployable fins () are in turn secured, and from which the fins are automatically deployed as soon as the body part has reached its rear position in which it is locked relative to the rest of the shell. One of the advantages of the invention is that in the flight position it gives the shell a greater length than is permitted by the charging position of the artillery piece launching the shell. This gives the shell considerably better stability in its trajectory towards the target. The invention also includes different embodiments of the body part () which can be tubular () or cylinder-shaped () and accommodate different types of fins () and also in certain configurations a built-in base-bleed unit (). The body part can also be divided into two parts (and) which rotate freely relative to each other and which allow the fins () to spin freely relative to the rest of the shell () which has been shown to make the latter more easily manoeuvred without impairing its directional stability.

Fin-stabilized shell

The present invention relates to a fin-stabilized missile ( ) of the type which is intended to be fired at high acceleration towards a defined target along its trajectory and which can be guided in the trajectory and which, for stabilizing it in the trajectory, is provided with stabilizing fins ( ) arranged at its rear end, and control elements ( ) which are arranged at its front end and are intended to guide the latter, and whose rear part, in which the fins are secured, consists of a body part ( ) which can rotate freely relative to the main part ( ) of the missile about a bearing ( ) arranged concentric to the longitudinal axis (L) of the missile ( ). According to the invention, said bearing ( ) is arranged near the dividing plane between the missile ( ) and the body part ( ) and has a short length in the longitudinal direction of the missile, this having been made possible by the fact that it has been given a large diameter compared with its length and it has been designed with special load-bearing contact surfaces ( ) which limit the stresses during ramming and firing and during the flight of the missile ( ) through the air. The freely rotatable body part ( ) for the fins ( ) can then in turn be axially displaced from a launch position located inside the missile to a flight position where the fins ( ) are pushed out behind the rear plane of the missile, where they can rotate freely.

Fin-stabilized guidable missile

The present invention relates to a method and a device designed for use with such shells ( ) that are equipped with a base-bleed unit ( ) for extended range and which during the first phase of their trajectory are spin-stabilised but which in the subsequent phase are subjected to spin deceleration by fins ( ) that deploy from the shell body and take over the stabilising function. More exactly the present invention is a method and a device that enables the said shells ( ) to achieve an effective and functional deployment of the fins ( ) at the desired point in time with simultaneous ejection of the base-bleed unit ( ) which at this point in time either no longer performs any useful function since it is burnt-out and solely constitutes a dead-weight or its function is no longer required. The basic idea behind the present invention is that the base-bleed unit ( ) and the fin protector ( ) that initially surrounds the fins ( ) shall be permanently integrated with each other and thereby can be removed/ejected as a single unit.

Growing community of inventors

Mörrum Karlskoga, Sweden

Ulf Holmqvist