Device forming a rear guidance interface for ammunition and ammunition comprising such devices

Abstract

The invention relates to a device (1) forming a rear guidance interface for ammunition, which ammunition comprises a projectile surrounded by a sabot having at least one rear support bearing (52), the device (1) comprising a linking element (2) and a contact interface element (3, 4), the linking element (2) comprising a fixing part (20) adapted to be fixed to the rear support bearing (52), a clamping part (21) and a guiding part (22), and the contact interface element (3, 4) comprising a pad-forming member (3) movably mounted, with guidance by the guiding part (22), relative to the linking element (2) between a retracted position and a protruding position in which the pad-forming member (3) protrudes at least partially out of the linking element (2) from the clamping part (21) and is adapted to be located at a diameter greater than that of the weapon tube (11),and a actuating element (4) of the sliding element (3) towards its projecting position. The present invention also relates to a munition comprising such devices (1). Figure to be published with the abbreviation: Fig. 6.

Description

Title of the invention: Device forming a rear guidance interface for ammunition and ammunition comprising such devices

[0001] The technical field of the invention is that of guidance and centering devices for ammunition during the internal ballistic phase, and more particularly of rear guidance for ammunition comprising a sabot surrounding an arrow-type projectile, which sabot includes at least one rear support bearing which allows the stabilization of the projectile during its ballistic path.

[0002] The present invention relates to a device forming a rear guidance interface and a munition comprising such devices in order to ensure a mechanical interface between a rear support span of a sabot and a weapon tube.

[0003] The invention can be applied to other types of projectiles besides arrow-type projectiles, in particular to all projectiles intended to be fired from a tube-type weapon. The device according to the invention is particularly suitable for elongated projectiles for which ensuring guidance within the weapon's tube is a problem.

[0004] In applications to fin-stabilized projectiles, it is known to use screws for the mechanical resistance to muzzle blast of the rear support plate and for the interface of the sabot with the barrel. For example, in the 120 mm fin-stabilized projectile marketed by the KNDS group under the reference 120 SHARD®, the mechanical interface between the rear support plate of the sabot and the barrel is ensured by three screws oriented radially to the axis of the projectile. More specifically, this ammunition uses a technical solution for artificially increasing the chamber volume in order to increase the propellant loading capacity and improve the efficiency of the propulsion system, namely to reduce the maximum pressure while maintaining a high muzzle velocity. To achieve this, the sabot's thrust plate is advanced well beyond the connecting cone in the barrel, which has the effect of increasing the length of the projectile's towed portion.Since vibrations and projectile movement within the barrel have a first-order impact on the external ballistic performance of the ammunition, a support bearing on the rear of the sabot is necessary to stabilize the projectile during its ballistic trajectory. Radial screws ensure the mechanical strength of this rear support bearing against muzzle blast, as well as its interface with the barrel. These screws are high-strength, hexagonal-head steel screws, specifically grade 12.9.

[0005] During the manufacturing process of this fin-stabilized ammunition, the radial screws are first screwed into the rear bearing surface of the sabot. However, these screws protrude. The screws must be machined to match the external profile of the ammunition and therefore compatible with insertion into a weapon tube. Specifically, the screws must be machined to the tube's diameter. Furthermore, once the screws are screwed into the sabot, it is no longer possible to mount the ammunition's connecting piece. This connecting piece, which is riveted to the projectile's belt, is a known component that joins the projectile and propellant parts of the ammunition. However, due to its external dimensions and shape, this connecting piece cannot be attached to the belt before the screws are machined.

[0006] Due to the constraints stated above, the current assembly method consists, after assembling the various sections of the sabot, of screwing the screws onto the projectile part by tightening them to the specified torque, matching each screw to its respective region of the bearing surface, then mounting the assembly on a lathe and machining it. A horizontal marking line is then made on the machined screw heads. The screws are then removed from the sabot by unscrewing them, and the connecting piece is positioned and riveted to the belt. Finally, each screw is reinserted through a hole provided in the connecting piece, and then the screws are tightened to the specified torque on the bearing surface, notably using a torque wrench, while ensuring that the marking line remains horizontal.

[0007] Thus, the use of these screws involves multiple assembly, disassembly, adjustment, machining and post-machining surface treatment operations, which makes the production of the munition complex, with a major impact on the industrialization phase.

[0008] Furthermore, these numerous operations are associated with a significant risk of human error. For example, there is a risk of insufficient tightening of the screws or incorrect repositioning of the screws after the connecting piece has been assembled, particularly due to an operator's oversight or a drift in the tightening torque setting of the torque wrench. Following such an error, the contact interface between the tube and the screw could no longer be maintained, which would result in premature and irreparable damage to the tube.

[0009] Furthermore, the machining operation of steel screw heads has the disadvantage of removing the zinc plating that protects the screws against corrosion. As a result, the screw heads are left exposed, without protection, and are quickly covered with rust. However, this rust is unacceptable from the point of view of the quality and lifespan of the part.

[0010] Yet another disadvantage of these screws is that, because they are machined to the diameter of the weapon tube, in the event of differences in circularity between the weapon tube and the ammunition, the mechanical interface with the weapon tube is no longer assured.

[0011] The invention proposes to replace these screws with a more sophisticated device, compatible with the technical solution of artificially increasing the volume of the chamber, capable of automatically ensuring a constant mechanical interface between the rear support area of ​​the sabot and the weapon tube, making it possible to avoid most of the costly operations in time and money related to the use of screws and unacceptable from an industrial point of view, in particular eliminating the steps of matching, machining, marking, unscrewing and rescrewing, avoiding any formation of rust, and capable of compensating for possible differences in circularity between the weapon tube and the ammunition.

[0012] The solution according to the invention is a device forming a rear guidance interface for ammunition, which ammunition comprises a projectile part intended to be fired from a weapon having a chamber communicating with a tube, the projectile part comprising a projectile surrounded by a sabot having at least one rear support bearing, the device comprising a connecting element and a contact interface element, the connecting element comprising a fastening part adapted to be fixed to the rear support bearing, a clamping part dimensioned so that, once the fastening part is fixed to the rear support bearing, it is located at a diameter greater than that of the rear support bearing and less than the internal diameter of the tube, and a guidance part, and the contact interface element comprising a movable-mounted pad-forming member, with guidance by the guidance part,relative to the connecting element between a retracted position and a protruding position in which the pad-forming element protrudes at least partially from the connecting element from the clamping part and is able to be located at a diameter greater than the internal diameter of the tube, and a load-bearing element for moving the pad-forming element towards its protruding position.

[0013] Such a device therefore ensures, in use, the mechanical stability of the rear support bearing while serving as a contact interface between the ammunition and the weapon tube, acting as a guide pad. In addition to this dual function, due to the movable mounting of the pad-forming element and its excitation towards its protruding position by the excitation element—a protruding position in which the pad-forming element is able to abut against the weapon tube—the device according to the present invention is capable of automatically compensating for differences in circularity between the weapon tube and the ammunition, thus providing a self-correcting function for the interface between the tube and the ammunition. Furthermore, such a device does not require any machining to be compatible with insertion into a weapon tube.

[0014] Advantageously, the contact interface element is received in the guide part, the pad-forming member being mounted to slide along the guide part, parallel to a fixing direction of the fixing part, the load-bearing member being applied against the pad-forming member. Such an assembly sliding allows for a simple structural device, with a reduced number of parts.

[0015] In a particular embodiment, the connecting element is a socket comprising:

[0016] - a cylindrical shaft with a longitudinal axis constituting the fixing part and having an external thread intended to screw into a corresponding bore provided in the rear support surface;

[0017] - a clamping collar extending in a plane perpendicular to the axis longitudinal section of the cylindrical shaft, forming the clamping part, which clamping collar is configured to be located between the rear support surface and the tube; and

[0018] - an internal cavity centered on the longitudinal axis of the shaft and opening towards the outside of the socket on the collar side, the internal cavity forming the guide part.

[0019] Thus, the connecting element ensures the mechanical strength of the device and the interface with the rear support area of ​​the shoe.

[0020] Preferably, the connecting element is made of steel.

[0021] Preferably, the connecting element further comprises a cap fixed in such a way removable from the cylindrical barrel, notably by threading, opposite the clamping collar. Such a cap allows the integration of the pad-forming element and the stress-bearing element into the connecting element.

[0022] In a particular embodiment, the sliding member is a pin comprising a head attached to a bearing, the internal cavity of the sleeve is a stepped internal cavity comprising a first recess on the flange side dimensioned to receive the head by sliding and a second recess dimensioned to receive the bearing by sliding, a face on the head side of the bearing, called the stop face, being able to bear against a first internal end-of-stroke shoulder formed between the first and second recesses, the loading member being arranged in the second recess.

[0023] Preferably, the pin is made of a friction-resistant material, in particular steel.

[0024] Preferably, the head has a cylindrical cross-section on the bearing side and a hemispherical cap-shaped cross-section at its free end. Thus, in use, the contact interface with the tube has a shape that prevents any damage to the tube.

[0025] In a particular embodiment, the skate-forming member further comprises a rod connected to the head by the bearing surface, the internal cavity further comprising a third recess dimensioned to slidably receive the rod, the load-bearing member being mounted around the rod and arranged between a rod-side face of the bearing surface, called thrust face, and a second internal shoulder formed between the second and third recesses.

[0026] Preferably, the internal cavity is a through cavity extending coaxially to the longitudinal axis of the cylindrical shaft.

[0027] Preferably, the first, second, and third recesses are cylindrical recesses having diameters corresponding, respectively, to the diameters of the head, the bearing surface, and the stem of the sliding element. Thus, sliding guidance of the sliding element is ensured by the guiding portion.

[0028] Preferably, the stressing member is an elastic stressing member formed by a spring or by a deformable body made of elastic material, in particular elastic polymer.

[0029] Advantageously, the clamping part includes a clamping recess, in particular a polygonal recess, intended to accommodate a clamping or screwing tool.

[0030] The imprint could be a polygonal imprint or an imprint formed by notches.

[0031] Preferably, the clamping part, where applicable the collar, has a frustoconical profile.

[0032] The invention also relates to a munition comprising a projectile part intended to be fired by a weapon having a chamber communicating with a tube, the projectile part comprising a projectile, in particular an arrow-type projectile, surrounded by a sabot, characterized in that it further comprises at least one device forming a rear guidance interface as defined above, for the or each device, the fixing part being fixed in the sabot radially to the axis of the projectile, and, in the protruding position, the element forming a pad being intended to come into contact with the weapon tube.

[0033] In a particular embodiment, the munition comprises three devices forming a rear guidance interface regularly distributed angularly around the sabot.

[0034] Preferably, the shoe comprises at least one rear support bearing spaced axially from a front support bearing, the rear support bearing being made up of three radial arms regularly distributed angularly around the shoe, each device being fixed to the end of an arm of the rear support bearing.

[0035] The invention will be better understood upon reading the following description, a description made in light of the accompanying drawings, drawings in which:

[0036] [Fig. 1] shows a cross-sectional view of the device forming the rear guidance interface according to the invention;

[0037] [Fig.2] represents a cross-sectional view of the connecting element of the device of the [Fig.1] alone ;

[0038] [Fig.3] is a perspective view of the device in [Fig.1];

[0039] [Fig.4] is a perspective view showing a device according to the invention mounted on the rear support range of a sabot of a munition, in its resting state;

[0040] [Fig. 5] is a cross-sectional view showing the device of [Fig. 1] mounted on the shoe of a munition and located opposite the connecting cone;

[0041] [Fig.6] is a view analogous to that of [Fig.5], showing the device opposite the inner wall of the weapon tube; and

[0042] [Fig.7] is a schematic representation, in longitudinal section, of a munition according to the invention, placed in the chamber of a weapon and equipped with devices forming a rear guidance interface according to the invention.

[0043] According to Figures 1 and 3, a device 1 forming a rear guidance interface according to a preferred embodiment of the present invention comprises a connecting element 2 in two pieces and a contact interface element 3, 4 in two pieces.

[0044] The linking element 2 allows the device 1 to be secured to the projectile part 5, 6 of a munition 10, in particular to the rear support span 52 of the sabot 5, as well as to guide the contact interface element 3, 4.

[0045] Referring to [Fig. 2], it can be seen that the connecting element 2 is in the form of a hollow sleeve generally comprising a fastening portion 20, a clamping portion 21, and a guide portion 22, and carrying a cap 23. The fastening portion 20, clamping portion 21, and guide portion 22 are formed as a single unit. The sleeve extends longitudinally along a longitudinal axis XI from a first end 2a to a second end 2b.

[0046] The mounting portion 20 is dimensioned and configured to be received and fixed in the projectile portion 5, 6. The mounting portion 20 is in the form of a cylindrical barrel extending along the longitudinal axis XI of the sleeve from the first end 2a. This barrel has an external thread adapted to screw into a corresponding bore 50 provided in the projectile portion 5, 6, in particular in the shoe 5, as can be seen in Figures 5 and 6. For this purpose, the length of the barrel is less than or equal to the depth of the corresponding bore 50 and the diameter of the external thread corresponds to the diameter of the internal thread of the bore 50. At the junction between the barrel and the clamping portion 21, the barrel has a narrowed section forming a V-groove 200 on the circumference of the barrel.This V-groove 200 is intended to cooperate with an internal bearing 500 of complementary shape provided at the through end of the bore 50.

[0047] The fastening part 20 carries a plug 23 at the first end 2b of the socket. The plug 23 is detachably fixed to the end region of the barrel opposite the clamping portion 21. In particular, the cap 23 has an external thread cooperating with an internal thread of the barrel. This cap 23 has a narrow portion carrying the external thread and a wide portion. These narrow and wide portions have a cylindrical cross-section, the diameter of the wide portion being greater than the diameter of the narrow portion. Thus, the wide portion covers the inner edge of the free end of the barrel. Advantageously, the surface of the wide portion opposite the clamping portion has a frustoconical shape, making it easier to screw and unscrew the cap 23.

[0048] The clamping portion 21 allows for the clamping, in particular the torque tightening, of the connecting element 2 onto the rear support bearing 52. The clamping portion 21 is dimensioned and configured so as not to protrude relative to the external profile of the ammunition 10, in other words, relative to the external profile of a connecting piece 7 of the ammunition 10, as shown in [Fig. 5], when this connecting piece 7 is attached to the projectile portion 5, 6. This connecting piece 7 is known in itself and has, for the device or devices 1, a radial through-hole 70 dimensioned and configured to be traversed by the clamping portion 21. In other words, the thickness of the clamping portion 21 is less than or equal to the distance between the projectile portion 5, 6 to which the barrel is attached and the outer wall of the connecting piece 7.The clamping portion 21 is in the form of a clamping collar extending transversely to the shaft, i.e., in a plane orthogonal to the longitudinal axis XI of the sleeve, at the second end 2b. This collar has a cylindrical section 210 on the shaft side, extended by a frustoconical section 211 whose diameter decreases from the cylindrical section 210 to the second end 2b of the sleeve. The face of the collar located at the second end 2b of the sleeve may have a polygonal recess (not shown) designed to accommodate a tightening tool. Alternatively, as can be seen in Figures 3 and 4, the recess may be formed of notches, in particular two diametrically opposed semi-cylindrical notches, passing through the collar and configured to receive a tightening tool. Thus, the recess allows for easy manipulation of the sleeve by a suitable tool.During the assembly phase, the socket must be torqued to the shoe; a torque wrench is the appropriate tightening tool. Such a wrench optimizes the fastening of the device without risk of loosening or damaging it.

[0049] The guide portion 22 is dimensioned and configured to receive and guide the contact interface element 3, 4. The guide portion 22 is in the form of an internal cavity centered on the longitudinal axis XI of the sleeve and extending through the plug 23 and the fixing and clamping portions 20 and 21. This internal cavity opens on either side of the sleeve at the first 2a and second 2b. ends. Alternatively, the internal cavity could open only at the second end 2b, namely at the collar 21. The internal cavity comprises first 220, second 221, and third 222 recesses. The first recess 220 is a cylindrical recess extending from the second end 2b of the socket to the second recess 221. More precisely, this first recess 220 is surrounded by the collar 21 and by the junction between the collar 21 and the barrel. The second recess 221 is a cylindrical recess extending from the first recess 220 to the third recess 222. The second recess 221 is surrounded by a major portion of the barrel. The diameter of the second recess 221 is greater than the diameter of the first recess 220. Thus, a first internal shoulder 223 at the end of the stroke is formed between the first 220 and second 221 recesses.The third recess 222 is a cylindrical recess extending from the second recess 221 to the first end 2a of the sleeve. The third recess 222 is formed through the plug 23. The diameter of the third recess 222 is smaller than the diameter of the second recess 221, and also smaller than the diameter of the first recess 220. Thus, a second internal shoulder 224 is formed between the second 221 and third 222 recesses.

[0050] The contact interface element 3, 4 provides a guiding pad function, in other words a mechanical interface between the shoe 5 and the tube 11, while compensating for differences in circularity between a weapon tube 11 and a munition 10 equipped with devices 1 according to the invention.

[0051] As can be seen in Figures 1, 5 and 6, the contact interface element comprises a pad-forming member 3 and a stress-forming member 4. The pad-forming member 3 is mounted to move in translation relative to the sleeve, coaxially with the longitudinal axis XI of the sleeve, between a retracted position and a protruding position. The stress-forming member 4 has the function of stressing the pad-forming member 3 towards its protruding position.

[0052] The sliding element 3 is in the form of a pin received and mounted to slide in the guide part 22. The mounting of the sliding element 3 in the guide part 22 allows the device 1 according to the invention to be mounted in a conventional shoe 5, without needing to modify said shoe 5.

[0053] This pin comprises a head 30, a bearing 31, and a shaft 32 formed as a single unit. The bearing 31 connects the head 30 and the shaft 32. The head 30 has a cylindrical cross-section and a rounded free end in the shape of a hemispherical cap. The rounded end, intended to come into contact with the weapon tube 11 during use, prevents damage to the inner wall of the weapon tube 11 as the projectile portion 5, 6 advances within the tube 11. The diameter of the cylindrical cross-section corresponds approximately to the diameter of the first recess 220, such that The head 30 is mounted to slide along the first recess 220. The bearing surface 31 has a cylindrical cross-section with a diameter greater than the diameter of the cylindrical cross-section of the head 30, and more specifically, the diameter of the bearing surface 31 corresponds approximately to the diameter of the second recess 221, such that the bearing surface 31 is mounted to slide along the second recess 221. The longitudinal translational movement of the bearing surface 31 towards the flange 21 is axially limited by the first internal shoulder 223 at the end of travel. The face of the bearing surface 31 that bears against this first shoulder 223 is called the abutment face 310. The rod 32 is a cylindrical rod extending from the center of the face of the bearing surface 31 opposite the abutment face 310, called the thrust face 311. Thus, the rod 32 constitutes a central guide axis.The diameter of the rod 32 corresponds approximately to the diameter of the third recess 222, such that the rod 32 is mounted to slide along the third recess 222. Thus, the sliding movement of the pin along the sleeve is reliably guided by the walls of the internal cavity 22. It should be noted that the pin might not have such a rod 32.

[0054] Thus, in the retracted position, the head 30 does not protrude from the external profile of the cartridge 10, and in the protruding position, part of the head 30 protrudes from the casing and from the external profile of the cartridge 10. In Figures 1, 3, 4 and 5, the pin 3 is shown at rest, i.e. not constrained towards its retracted position by the weapon tube 11, and therefore held in its protruding position by the activating member 4. In [Fig. 6], the pin 3 is pushed towards its retracted position, against the pushing force of the activating member 4, under the effect of the cooperation of the head 30 with the internal wall of the tube 11.

[0055] In the preferred embodiment of the invention, the stressing member 4 is an elastic stressing member 4 formed by a spring, in particular a cylindrical compression spring made of an elastomeric material, or by a deformable body made of an elastic material, for example, an elastic polymer. Of course, the stressing member 4 is not limited to such an elastic member. This elastic member 4 is disposed in the second recess 221, between the thrust face 311 of the bearing surface 31 and the second internal shoulder 224 of the cavity 22. An internal annular channel 40 is provided through the elastic member 4, coaxially with the longitudinal axis XI of the sleeve. This channel 40 has a diameter corresponding to the diameter of the rod 32. Thus, the rod 32 is received in the channel 40 and is surrounded by the elastic element 4. The elastic element 4 is configured to apply a pushing force on the pushing face 311 and thus to move the pin towards its protruding position.In other words, the direction of the thrust force is coaxial with the longitudinal axis XI of the sleeve and the direction of the thrust force is outwards from the sleeve on the second end side 2b.

[0056] Thus, the device 1 according to the invention has a simple and robust structure comprising four parts consisting of the sleeve 20, 21, 22, the plug 23, the pin 3, and the elastic element 4. The device 1 is obtained by a simple and quick assembly of these four parts. Indeed, it is sufficient to insert the pin 3 into the sleeve through the guide portion 22, from the end opposite the collar 21, until the bearing surface 21 abuts against the first internal shoulder 223, to insert the elastic element 4 into the second recess 221 and around the rod 32, and then to screw the plug 23 onto the shaft 20.

[0057] As can be seen in Figures 4 to 6, and very schematically in [Fig.7], the device 1 according to the present invention is intended to be used in a munition 10, in particular a munition 10 of the fin-stabilized arrow or fin-stabilized projectile type, for example a 120 mm fin-stabilized projectile, for guiding the munition 10 in the tube 11. The fin-stabilized arrow-type munition 10 consists of a projectile part 5, 6, comprising a sabot 5 and a sub-projectile 6, a propellant part 8, 9, comprising a socket 8 or cartridge containing a propellant charge 9, and a connecting piece 7.

[0058] In [Fig.7], the munition 10 is shown positioned in a chamber 12 of a weapon, the projectile part 5, 6 being partially engaged in the tube 11 of the weapon, the front part of the chamber 12 having a connecting cone 120, and the tube 11 being a smooth tube.

[0059] The sub-projectile 6 is a penetrator or arrow 60 having at its rear part a tail 61.

[0060] The arrow 60 is held by a sabot 5 to compensate for the dimensional difference between the arrow 60 and the internal diameter of the gun tube 11. This sabot 5 has a front support bearing 51 or a belt, of the caliber, adapted to close the gap between the arrow 60 and the internal wall of the tube 11, and a rear support bearing 52 located axially behind the front support bearing 51. The rear support bearing 52 consists of radial arms 520, regularly distributed angularly around the sabot 5. Each radial arm 520 has, at its free end, a bore 50 adapted to receive the device 1 according to the invention in order to guide the sabot 5 in the gun tube 11. Thus, in the case where the rear support bearing 52 has three radial arms 520, the resulting ammunition 10 has three devices 1 forming a guidance interface rear. Of course, the number of radial arms 520 and devices 1 is not limited to three.Similarly, the support span could include a cylindrical span instead of radial arms.

[0061] The socket 8 of the propellant part 8, 9 is closed at the rear by a base 80 and contains a propellant charge 9. A primer 81 is integral with the base 80. The socket 8 is made integral with the sabot 5 by means of the connecting piece 7.

[0062] The connecting piece 7 comprises, in a known manner, a cylindrical front portion 71, a cylindrical rear portion 72 and a conical portion 73 ensuring the connection of the rear portion 72 with the front portion 71.

[0063] The cylindrical front portion 71 has, at its end on the side of the conical portion 73, a number of radial through-holes 70 regularly distributed angularly, suitable for being positioned opposite the bores 50 of the radial arms 520 of the rear support bearing 52 of the sabot 5. The diameter of these through-holes 70, of circular cross-section, is at least equal to the diameter of the collar 21 of a device 1. In the assembled state, the devices 1 therefore extend radially around the longitudinal axis X2 of the munition 10. The outside diameter of the connecting piece 7 at the level of this front portion 71 is slightly greater than the diameter of the tube 11.

[0064] The cylindrical rear portion 72 is secured to the sleeve 8, for example by bonding. The outside diameter of the rear portion 72 is substantially equal to the outside diameter of the sleeve 8. Although not shown for clarity, the cylindrical front portion 71 is riveted to the belt.

[0065] When the munition 10 according to the invention is positioned, the forward portion 71 of the connecting piece 7 is aligned with the connecting cone 120. The pad-like element 3 of each device 1 is then pushed into its protruding position by the actuating element 4, as shown in [Fig. 5], a position in which the hemispherical cap-shaped section of the head 30 has a diameter greater than that of the tube 11. The ignition of the propellant charge 9 will cause the cartridge case 8 to separate from the projectile portion 5, 6 carrying the connecting piece 7 and allow the projectile portion 5, 6 to advance into the tube 11. When the forward portion 71 of the connecting part 7 enters the tube 11, the pad-like element 3 of each device 1, which comes into contact with the inner wall of the tube 11, brings the actuating element 4 of the compression spring type to pre-stress and crush, as shown in [Fig.6].The appropriate dimensioning of the stressing element 4, coupled with a mechanical stop, then makes it possible to maintain a constant contact interface with the tube 11, thus achieving the centering and guidance of the projectile part 5, 6, and this independently of the geometry of the tube 11 or the geometry of the sabot 5. In other words, this mobile mounting of the pad-forming element 3 of each device 1, under the effect of an elastic element 4, makes it possible to ensure automatic compensation of differences in circularity between the inner wall of the tube 11 and the ammunition 10, thus ensuring optimal and reliable guidance of the rear part of the projectile during the internal ballistic phase.

[0066] Furthermore, the assembly of this munition 10 is easy and quick, the only operation necessary for mounting the devices 1 according to the invention on the projectile part 5, 6 being a simple screwing of the devices 1 forming rear guide interface into the radial arms 520 of the shoe 5 directly after the installation of the connecting part 7. In particular, no rework or adjustment operation of the device 1 is required, which makes the solution industrially viable, considerably reduces the risks of assembly error and prevents the appearance of rust on the device 1.

[0067] It is understood that the particular embodiment just described has been given by way of example and not limitation, and that modifications may be made without departing from the scope of the present invention.

Claims

Demands

1. Device (1) forming a rear guidance interface for ammunition (10), said ammunition (10) comprising a projectile portion (5, 6) intended to be fired from a weapon having a chamber (12) communicating with a tube (11), the projectile portion (5, 6) comprising a projectile (6) surrounded by a sabot (5) having at least one rear support bearing (52), the device (1) comprising a connecting element (2) and a contact interface element (3, 4), the connecting element (2) comprising a fastening portion (20) adapted to be fixed to the rear support bearing (52), a clamping portion (21) dimensioned so that, once the fastening portion (20) is fixed to the rear support bearing (52), it is located at a diameter greater than that of the rear support bearing (52) and less than the internal diameter of the tube (11), and a guidance portion (22), and the contact interface element (3, 4) comprising a sliding element (3) mounted to move,with guidance by the guiding part (22), relative to the connecting element (2) between a retracted position and a protruding position in which the pad-forming member (3) protrudes at least partially out of the connecting element (2) from the clamping part (21) and is able to be located at a diameter greater than the internal diameter of the tube, and a load-bearing member (4) of the pad-forming member (3) towards its protruding position.

2. Device (1) according to claim 1, characterized in that the contact interface element (3, 4) is received in the guide part (22), the pad-forming member (3) being mounted movable in translation by sliding along the guide part (22), parallel to a fixing direction of the fixing part (20), the stressing member (4) being applied against the pad-forming member (3).

3. Device (1) according to any one of claims 1 and 2, characterized in that the connecting element (2) is a sleeve comprising: - a cylindrical shaft with longitudinal axis (XI) constituting the fixing part (20) and having an external thread intended to screw into a corresponding bore (50) provided in the rear support surface (52); - a clamping collar extending in a plane perpendicular to the longitudinal axis (XI) of the cylindrical barrel and constituting the clamping part (21), which clamping collar is configured to be located between the rear support surface (52) and the tube (11); and - an internal cavity centered on the longitudinal axis (XI) of the barrel and opening outwards from the sleeve on the side of the collar (21), the internal cavity constituting the guiding part (22).

4. Device (1) according to claim 3, characterized in that the pad-forming member (3) is a pin comprising a head (30) integral with a bearing (31), the internal cavity of the sleeve is an internal stepped cavity comprising a first recess (220) on the flange side (21) dimensioned to receive the head (30) by sliding and a second recess (221) dimensioned to receive the bearing (31) by sliding, a face on the head side (30) of the bearing (31), called the stop face (310), being able to bear against a first internal shoulder (223) of the end of travel formed between the first (220) and second (221) recesses, the stressing member (4) being arranged in the second recess (221).

5. Device (1) according to claim 4, characterized in that the pad-forming member (3) further comprises a rod (32) connected to the head (30) by the bearing (31), the internal cavity further comprising a third recess (222) dimensioned to receive the rod (32) by sliding, the stressing member (4) being mounted around the rod (32) and being arranged between a rod-side face (32) of the bearing (31), called the thrust face (311), and a second internal shoulder (224) formed between the second (221) and third (222) recesses.

6. Device (1) according to any one of claims 1 to 5, characterized in that the stressing member (4) is an elastic stressing member formed by a spring or by a deformable body made of elastic material, in particular elastic polymer.

7. Device (1) according to any one of claims 1 to 6, characterized in that the clamping part (21) has a clamping recess, in particular a polygonal recess, intended to accommodate a clamping or screwing tool.

8. Munition (10) comprising a projectile portion (5, 6) intended to be fired from a weapon having a chamber (12) communicating with a tube (11), the projectile portion (5, 6) comprising a projectile (6), in particular an arrow-type projectile, surrounded by a sabot (5), characterized in that it further comprises at least one device (1) forming a rear guidance interface according to any one of claims 1 to 7, for the device or each device (1), the fixing part (20) being fixed in the shoe (5) radially to the axis (X2) of the projectile (6), and, in the protruding position, the element forming a skid (3) being intended to come into contact with the weapon tube (H).

9. Munition (10) according to claim 8, characterized in that it comprises three devices (1) forming a rear guidance interface regularly distributed angularly around the sabot (5).

10. Munition (10) according to claim 9, characterized in that the sabot (5) has at least one rear support bearing (52) axially spaced from a front support bearing (51), the rear support bearing (52) being made up of three radial arms (520) regularly distributed angularly around the sabot (5), each device (1) being integral with the end of an arm (520) of the rear support bearing (52).

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