EP4105591B1 - Stationing device for a projectile - Google Patents

Description

The technical field of the invention is that of devices for positioning projectiles in a chamber of a rifled weapon, in particular a large caliber weapon.

The purpose of positioning a projectile, that is, the insertion of the projectile into the chamber of the barrel of the rifled weapon, is to wedge the projectile into the forcing cone of the weapon by means of its belt so that it is held in this position within the weapon while waiting to be fired. During positioning, the projectile is roughly guided to the forcing cone by the internal wall of the barrel.

To position a projectile, it is necessary to force the projectile back inside the barrel to the forcing cone. Since projectiles are heavy, they must be forced back at a sufficient speed to become wedged and ensure a seal in the forcing cone without the risk of falling back down, regardless of the elevation position of the weapon barrel.

Several methods and devices for positioning are known.

Conventionally, the projectile is positioned using a pusher cylinder that pushes the projectile into the forcing cone. The main disadvantage of such a device is its slow loading. Indeed, the times for accompanying the projectile and withdrawing the device are too long and significantly penalize the rate of fire.

To overcome this drawback, it is known to use an impulse device which gives the projectile a strong acceleration allowing it to move by its own inertia to its position in the tube. The projectile is thus projected into the tube by the impeller, which remains outside the weapon. The French patent FR3043190 B1 describes an example.

However, with such a booster device, it may happen that the projectile is not positioned correctly, which leads to possible projectile detachments or belt sealing problems.

Indeed, the internal diameter of the tube being substantially larger than the diameter of a projectile, the chamber allows unwanted oscillations of the projectile during the impulse. Such oscillations can cause unsatisfactory attachments of the projectile in the forcing cone because the projectile is off-axis relative to the longitudinal axis of the tube when it comes into contact with the forcing cone.

Furthermore, the tube has in its lower rear part an area called a spoon which corresponds to a slight recess in the chamber. This spoon is intended to allow propellant charges to be housed partly within it and has a retaining edge which is located towards the rear of the chamber in order to retain the charges in the chamber when the weapon is pointed at a positive site. Thus, the spoon causes a local increase in the diameter of the chamber which then allows, when the projectile is positioned, wider oscillations of the projectile in a vertical plane passing through the axis of the weapon. The risk of unsatisfactory attachment of the projectile is therefore particularly present when the projectile oscillates in said vertical plane.

In order to solve this problem of incorrect positioning of the projectile, the US patent application US2020/0326146 A1 proposes as a solution to use, in addition to the impeller, an additional rammer, called a correction rammer, allowing a second positioning of the projectile in the event of a stall, by applying a more moderate thrust to the projectile than during the initial impulse by the impeller.

The use of such a correction rammer, however, has the disadvantage of increasing the size of the positioning device, which can make its integration into an artillery piece difficult.

Furthermore, although this solution can in principle ensure correction of incorrect projectile positioning, the fact remains that the rate of fire can still be affected.

THE European patent EP1102023 B1 describes a positioning device according to the preamble of claim 1. In this device, a stretcher is secured to a rammer and slides on a ramp aligned with the axis of the barrel. The stretcher is accelerated along the ramp and stops near the entrance to the chamber. The ramming of the ammunition is achieved by the effect of its inertia. However, since the ammunition is guided only to an area close to the entrance to the chamber, there is a risk of the ammunition being misaligned with respect to the axis of the barrel beyond this area.

The present invention proposes a positioning device aimed at ensuring correct positioning of the projectile from the initial impulse by the impeller, by reducing the risks of the projectile being misaligned with respect to the longitudinal axis of the weapon, whether or not the latter includes a spoon.

The invention thus relates to a device for positioning a projectile in a chamber of a weapon barrel, comprising a discharge impeller comprising a chassis which defines a projectile receiving space, extending along an axis of the chassis and open at one end of the chassis, which end is intended to be placed in facing an entrance of the tube, and at least one projectile thrust member capable of being driven by an alternating translational movement, along said axis, between an initial position, before pushing back the projectile, and a final position, from which the projectile is projected towards its positioning position, the positioning device further comprising a support for guiding the introduction of the projectile into the tube, the support being rigid and integral with the at least one thrust member so as to be movable in translation with the latter, the support being configured to be in the reception space when the at least one thrust member is in the initial position and allow the projectile to be supported by the support before pushing back, and to be at least partly cantilevered from said end of the chassis when the at least one thrust member is in the final position, characterized in that, in said final position, the at least one thrust member has been moved to the vicinity of said end of the chassis, by which the projectile is projected from said end and the support, intended to penetrate at least partly into the tube during the repulsion, is capable of limiting the amplitude of any possible oscillation of the projectile during its projection towards its position of placement.

Advantageously, in the case where the positioning device is intended for positioning the projectile in the chamber of a weapon tube which includes a spoon in its rear part, the support constitutes a means for closing the spoon in the final position of the at least one thrust member. The expression "closing the spoon" means that the support extends above the spoon to cover a major part of the latter, to an extent such that the support forms a bridge extending from the retaining edge to the vicinity of the end of the spoon where the latter joins the conical part of the chamber. This results in the sizing of the length of the support according to the dimensions of the spoon.

Advantageously, the support comprises an introduction part, capable of penetrating into the tube during the discharge, which includes the front end of the support, and a connecting part by which the support is secured to the at least one thrust member, the introduction part being in the form of a plate of uniform thickness and curved in the shape of a trough following an arc of a cylinder of revolution whose axis is aligned with the axis of the chassis, the free transverse edge of the plate forming the front end of the support.

Advantageously, the introduction part and the connecting part are formed by the same curved, trough-shaped plate.

Advantageously, the plate forming the introduction part, and where appropriate also the connecting part, has an opening angle equal to a constant value, for example a value between 100° and 180°, over all or part of its length, for example over three quarters of its length starting from the connecting part. The opening angle may advantageously be 170°. For smaller opening angles it may be necessary to stiffen the support, which can be done for example by adding stiffeners.

Advantageously, said plate has its opening angle which, from its free transverse edge, increases progressively, for example from a value of 60°, until it is equal to said constant value of the opening angle.

Provide such variation of the opening angle of the introduction part in the region of its transverse edge free allows on the one hand to prevent the support from catching on the tube during introduction and, on the other hand, to take into account the progressive reduction of the diameter of the chamber towards the front to avoid any jamming between the shell and the internal face of the chamber.

The dimensions of the support, in particular of the introduction part, will be advantageously chosen taking into account the dimensions of the spoon of the chamber in which the projectile is to be placed, so that during the movement of the introduction part inside the chamber, the introduction part can come into contact, by its sides, with the edges of the spoon.

Advantageously, the support is coated, at least on the support areas, if necessary on the entire plate forming the support, with an anti-friction coating, preferably of the nickel-chemical type or nickel-chemical type loaded with PTFE.

The support can be made of metal alloy or composite material.

The at least one thrust member may be a pusher comprising a bearing surface intended to correspond with a rear face of the projectile.

• [Fig. 1] est une vue schématique de dessus, en coupe longitudinale, de la partie d'entrée d'un tube d'arme et du dispositif de mise à poste selon l'invention, avec un projectile supporté par le support et en position initiale ;
• [Fig. 2] est une vue analogue à la Figure 1, le dispositif de mise à poste étant en position finale, à l'instant où le projectile est projeté par l'impulseur vers sa position de mise à poste ;
• [Fig. 3] est une vue schématique en coupe transversale du dispositif de mise à poste, prise le long du plan A-A sur la Figure 1 ; et
• [Fig. 4] est une vue schématique de côté, en coupe longitudinale, du tube et du dispositif de mise à poste en position finale.

The invention will be better understood on reading the following description of a particular embodiment, a description made in light of the appended drawings, drawings in which:

• [ Fig. 1 ] is a schematic top view, in longitudinal section, of the entry part of a weapon tube and of the positioning device according to the invention, with a projectile supported by the support and in the initial position;
• [ Fig. 2 ] is a view analogous to the Figure 1 , the positioning device being in the final position, at the instant when the projectile is projected by the impeller towards its positioning position;
• [ Fig. 3 ] is a schematic cross-sectional view of the positioning device, taken along plane AA on the Figure 1 ; And
• [ Fig. 4 ] is a schematic side view, in longitudinal section, of the tube and the positioning device in final position.

If we refer to the Figures 1 to 4 , it can be seen that a positioning device 1 according to a particular embodiment of the present invention comprises a discharge impeller 2, used to project a projectile P, shown in dotted lines, into a chamber 101 of a tube 100 to its positioning position, and a support 3 used to guide the introduction of the projectile P into the tube 100 in a manner making it possible to limit possible oscillations of the projectile P.

The discharge impeller 2 is a conventional impeller, for example of the type described in the patent FR3043190 B1 .

The impeller 2 thus comprises, in a known manner, a chassis 20 in which is defined a receiving space 21 extending along an axis A1 of the chassis 20 and opening onto an opening 22, called the discharge opening, at a first end 20a, also called the discharge opening, of the chassis 20. The chassis 20 also comprises an opening 23, called the introduction opening, through which a projectile P can be introduced into the receiving space 21, this introduction opening being here on the top. It could also be provided that the introduction opening, used for the introduction of the projectile P into the impeller 2, is the discharge opening 22 or is arranged at another location of the chassis 20.

The impeller 2 also comprises a thrust member 24 movable in translation along the axis A1 alternately between an initial position, illustrated in the Figure 1 and where the thrust member 24 is located on the rear side of the chassis, and a final position illustrated on the Figures 2 And 4 , where the thrust member 24 has been moved to the vicinity of the discharge end 20a, as is well known. The thrust member 24 will be guided and moved by any suitable means, and reference may for example be made again to the patent FR3043190 B1 .

The movement of the thrust member 24 from the initial position to the final position will be defined so as to obtain a projection of the projectile P. This movement will thus present a strong acceleration from the initial position and a strong deceleration on approaching the final position.

The pushing member 24 is here formed by a pusher 25 having a bearing face 25a which will come into contact with the rear face of the projectile P in order to push the latter.

It is emphasized here that the present invention is not limited to a specific type, number, guidance and drive of the thrust member 24.

The positioning device 1 is distinguished in that the impeller 2 is provided with a support 3 which is integral with the thrust member 24 and intended to receive the projectile P before being pushed back, the support 3 also being intended to penetrate partly into the tube 100 with the projectile P during the latter's being pushed back, while the thrust member 24 remains outside the tube 100.

The support 3 is thus constructed and dimensioned so as to be able to support the weight of the projectile P and to be partially introduced into the tube 100 during the discharge, in the gap present between the body of the projectile and the inner wall of the chamber 101. Thus, in the dimensioning of the support 3, the dimensions of the projectile P and of the tube 100 will be taken into account, and in particular the external diameter of the body of the projectile P and the diameter(s) interiors and lengths of the different interior walls of the tube 100.

In the present particular embodiment, the support 3 is formed by a simple plate 30 curved in the form of a bucket following an arc of a cylinder of revolution whose axis is the axis A1 of the chassis 20. The plate 30 thus has a concave inner face 30a, the concavity of which is here turned towards the introduction opening 23, on which the projectile P will be placed, and a convex outer face 30b, the convexity of which is turned away from said introduction opening 23. In other words, in use, the concavity of the inner face 30a will be turned upwards and the convexity of the outer face 30b will be turned downwards. In order to ensure the stability of the projectile P once placed on the plate 30, the radius of the inner face 30a may be only slightly greater than the outer radius of the body of the projectile P. The radius of the outer face 30b may be only slightly less than the inner radius of the entrance to the weapon chamber 100.

It is emphasized here that the expression "axis of the chassis" means the straight line which will be aligned with the longitudinal axis of the projectile P supported by the support 3 and which during the pushing back operation is also aligned with the longitudinal axis A2 of the tube 100. It would therefore be possible to provide a chassis whose geometric axis is not aligned with the axis A2 during pushing back, without however departing from the scope of the present invention.

It should also be noted that, for the sake of clarity in the drawings, certain thicknesses, and in particular that of plate 30, have been exaggerated.

The plate 30 comprises an insertion part 31 and a connecting part 32. The insertion part 31 is the one that penetrates the tube 100 when the pusher 25 is in the final position, as can be better seen in the Figure 4 , and the connecting part 32 is the one which does not penetrate into the tube 100 and by means of which the support 3 is made integral with the pusher 25.

The support 3 may be secured to the pusher 25 by any appropriate means, such as for example by welding the outer face 30b to a semi-cylindrical bearing surface 25b of the pusher 25 provided for this purpose.

If we refer more particularly to the Figure 4 , it can be seen that the plate 30 is here semi-cylindrical over three quarters of its length from its transverse edge fixed to the pusher 25, and which constitutes the rear end of the support 3, then its opening angle α decreases progressively, from a value of 180° in the semi-cylindrical part, up to the transverse edge 30a of the plate, where the opening angle is for example 60°.

The reduction of the opening angle α can be done according to a constant slope, as illustrated in the Figure 4 where it can be seen that each longitudinal edge of the plate 30 comprises a rectilinear segment 30d which is located at the height of the axis A1 and an inclined rectilinear segment 30e. Of course, one could foresee a reduction of the opening angle α according to a non-constant slope, or even no reduction.

In the initial position of the thrust member 24, illustrated in the Figure 1 , the support 3 is located in the receiving space 21 and is ready to receive the projectile P, which is placed on the support 3 manually or by suitable handling means, which are well known and will therefore not be described in detail.

The positioning device 1 is then moved, again by any suitable well-known means, so that the discharge opening 22 is aligned with the inlet 102 of the tube 100.

The thrust member 24 can then be moved to the final position, illustrated in the Figures 2 And 4 , of so as to push back the projectile P by projecting it into the tube 100 to its position of placement.

During this movement to the final position, the plate 30 enters with the projectile P into the tube 100, passing through the gap present between the body of the projectile P and the inner walls of the tube 100.

Thus, during this movement, the support 3 will constitute an obstacle preventing the projectile P from tilting towards the lower part of the tube 100 when the projectile P enters the latter, and will therefore limit the amplitude of any possible oscillation of the projectile P.

This is particularly useful in the case where the tube 100 has a spoon 103. As indicated above, the spoon 103 is formed by a recess in the inner wall of the tube 100, immediately after the inlet 102, so that the inlet 101 has a cylindrical lower bearing surface 104 forming a rim 105 intended to retain the propellant charges.

Despite the fact that the spoon 103 in principle creates an additional space allowing a greater amplitude of oscillation for the projectile P, the support 3 allows the projectile P to behave during repulsion as if the spoon 103 were not present.

When the support 3 enters the tube 100, it will come to bear both on the lower bearing surface 104 and on the two longitudinal edges 106 of the spoon 103, at the level of two lateral zones of the support 3 circled in dotted lines on the Figure 2 , which in the present embodiment correspond to the areas where the opening angle α of the plate 30 decreases.

Furthermore, due to the conical shape of the weapon chambers, the support of the two lateral support zones of the support 3 will be on the conical generatrices of the chamber 101, of so that the support 3 will be centered naturally and progressively in the chamber 101.

In order not to reduce the speed communicated to the projectile P by the thrust member 24, the plate 30 may advantageously be coated, on its inner 30a and outer 30b faces, with an anti-friction coating, preferably of the nickel-chemical type or nickel-chemical type loaded with PTFE.

Finally, in order to avoid jamming of the support 3 between the projectile P and the tube 100, the support 3 will also be sized, depending on the dimensions of the tube 100, so that a clearance d1 is present between the front end 30c of the support 3 and the tube 100, clearance measured in the plane transverse to the axis A2 of the tube 100 and passing through the front end 30c, when the thrust member 24, and therefore the support 3, is in the final position. The clearance d1 will preferably be at least 1.5 mm.

It can therefore be seen that the present invention makes it possible to significantly limit any oscillations of the projectile during its repulsion, even in the presence of a spoon in the chamber, and therefore to considerably improve the reliability of the repulsion device, for successful positioning on the first shot.

The solution according to the present invention is also particularly simple to implement and inexpensive.

It is understood that the particular embodiment which has just been described has been given for informational purposes and is not limiting, and that modifications may be made without departing from the present invention.

Claims (9)

1. - A device (1) for positioning a projectile (P) in a chamber (101) of a gun tube (100), comprising an impulse rammer (2) comprising a frame (20) that defines a space (21) for receiving a projectile, extending along an axis (A1) of the frame (20) and open at one end (20a) of the frame (20), which end (20a) is intended to be placed opposite an inlet (101) of the tube (100), and at least one member (24) for pushing the projectile (P) capable of being driven in an alternating translational movement, along said axis (A1), between an initial position, before the projectile (P) is rammed, and a final position, from which the projectile (P) is projected toward its positioning location, the positioning device (1) further comprising a support (3) for guiding the introduction of the projectile (P) into the tube (100), the support (3) being rigid and secured to the at least one pushing member (24) so as to be movable in translation with the latter, the support (3) being configured to be in the receiving space (21) when the at least one pushing member (24) is in the initial position and allow the projectile (P) to be supported by the support (3) before ramming, and to be at least partly cantilevered from said end (20a) of the frame (20) when the at least one pushing member (24) is in the final position, characterised in that, in said final position, the at least one pushing member (24) has been moved to the vicinity of said end (20a) of the frame (20), whereby the projectile (P) is projected from said end (20a) and the support (3), intended to penetrate at least partly into the tube (100) during ramming, is able to limit the amplitude of any possible oscillation of the projectile (P) during its projection toward its positioning location.
2. - The positioning device (1) according to claim 1, intended for positioning the projectile (P) in the chamber (101) of a gun tube (100) that comprises a scoop (103) in its lower rear part, the positioning device (1) being characterised in that the support (3) constitutes a means for closing the scoop (3) in the final position of the at least one pushing member (24).
3. - The positioning device (1) according to any one of claims 1 and 2, characterised in that the support (3) comprises an introduction part (31), capable of penetrating into the tube (100) during ramming, which includes the front end (30c) of the support (3), and a connecting part (32) whereby the support (3) is secured to the at least one pushing member (24), the introduction part (31) taking the form of a plate (30) of uniform thickness curved in the shape of a trough along an arc of a cylinder of revolution whose axis is aligned with the axis (A1) of the frame (20), the free transverse edge (30c) of the plate (30) forming the front end (30c) of the support (3).
4. - The positioning device (1) according to claim 3, characterised in that the introduction part (31) and the connecting part (32) are formed by the same plate (30) curved in the form of a trough.
5. - The positioning device (1) according to any one of claims 3 and 4, characterised in that the plate (30) forming the introduction part (31), and if applicable also the connecting part (32), has an opening angle (α) equal to a constant value, for example a value between 100° and 180°, over all or part of its length, for example over three quarters of its length starting from the connecting part (32).
6. - The positioning device (1) according to claim 5, characterised in that said plate (30) has its opening angle (α) which, starting from its free transverse edge (30c), increases progressively, for example starting from a value of 60°, until it is equal to said constant value of the opening angle (α).
7. - The positioning device (1) according to any one of claims 1 to 6, characterised in that the support (3) is coated, if applicable over the entire plate (30) forming the support (3), with an anti-friction coating, preferably of the chemical-nickel or PTFE-filled chemical-nickel type.
8. - The positioning device (1) according to any one of claims 1 to 7, characterised in that the support (3) is made of metal alloy or of composite material.
9. - The positioning device (1) according to any one of claims 1 to 8, characterised in that the at least one pushing member (24) is a pusher (25) comprising a bearing surface (25a) intended to correspond with a rear face of the projectile (P).