Device forming a rear guide interface for a munition and munition comprising such devices
The rear guidance interface device addresses the complexity and reliability issues of fin-stabilized projectile assembly by providing a self-compensating mechanism for circularity differences, ensuring stable mechanical interfaces and reducing assembly errors and rust formation.
Patent Information
- Application Number
- PCT/IB2025/055679
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2024-06-03
- Filing Date
- 2025-06-03
- Publication Date
- 2025-12-11
AI Technical Summary
The current assembly process for fin-stabilized projectiles involves complex and error-prone operations with radial screws, leading to potential damage, rust formation, and inconsistent mechanical interfaces due to machining and torque adjustments, which complicates production and increases the risk of human error.
A rear guidance interface device comprising a connecting element with a clamping and guide part, and a movable pad-forming element, which automatically compensates for circularity differences between the projectile and the weapon tube, eliminating the need for machining and ensuring a stable mechanical interface.
The device simplifies assembly, reduces the risk of human error, prevents rust, and maintains a consistent mechanical interface, enhancing industrial efficiency and reliability.
Smart Images

Figure IB2025055679_11122025_PF_FP_ABST
Abstract
Description
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 involving fin-stabilized projectiles, it is common practice to use screws for the mechanical resistance to muzzle blast of the rear support plate and for the interface between the sabot and 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 projectile's axis. More specifically, this ammunition uses a technical solution to artificially increase 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 positioned well beyond the forcing cone in the barrel, which has the effect of increasing the length of the projectile's thrust portion.Since vibrations and projectile movement within the barrel have a first-order impact on the ammunition's external ballistic performance, 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 support of the sabot. However, these screws protrude beyond the external profile of the ammunition and must therefore be machined to be compatible with insertion into a weapon tube. More specifically, the screws must be machined to the diameter of the tube. 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 belt, is a known component that joins the projectile and propellant parts of the ammunition. However, this connecting piece cannot be attached to the belt before the screws are machined due to its external dimensions and shape.
[0006] Due to the constraints outlined above, the current assembly process involves, after assembling the various sections of the sabot, screwing the screws onto the projectile section to the specified torque, matching each screw to its respective region of the bearing surface, and 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 pre-drilled hole in the connecting piece, and the screws are then torqued to the specified torque on the bearing surface, typically 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 ammunition 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 deviation in the torque setting of the torque wrench. Following such an error, the contact interface between the tube and the screw could be compromised, resulting in premature and irreparable damage to the tube.
[0009] Furthermore, machining steel screw heads has the drawback of removing the zinc plating that protects them against corrosion. As a result, the screw heads are left exposed, unprotected, and quickly become covered in rust. This rust is unacceptable from the perspective of the part's quality and lifespan.
[0010] Yet another disadvantage of these screws is that, because they are machined to the diameter of the gun tube, in case of differences in circularity between the gun tube and the ammunition, the mechanical interface with the gun 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 guide part, and the contact interface element comprising a movable-mounted pad-forming member, with guidance by the guide 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, in use, ensures the mechanical stability of the rear support bearing while simultaneously serving as a contact interface between the ammunition and the barrel, acting as a guide pad. In addition to this dual function, due to the movable mounting of the pad-like element and its excitation towards its protruding position by the excitation element—a protruding position in which the pad-like element is able to abut against the barrel—the device according to the present invention is capable of automatically compensating for differences in circularity between the barrel and the ammunition, thus providing a self-correcting function for the interface between the barrel and the ammunition. Furthermore, such a device does not require any machining to be compatible with insertion into a barrel.
[0014] Advantageously, the contact interface element is received in the guide section, the sliding element being mounted to move along the guide section, parallel to a direction of attachment of the mounting section, the load being applied against the sliding element. Such a sliding assembly allows for a simple structural device with a reduced number of parts.
[0015] In one 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 be screwed into a corresponding bore provided in the rear support area;
[0017] - a clamping collar extending in a plane perpendicular to the longitudinal axis of the cylindrical barrel and constituting 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 barrel and opening outwards towards the outside of the socket on the collar side, the internal cavity constituting the guiding part.
[0019] Thus, the connecting element ensures the mechanical stability 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 also includes a plug removably fixed to the cylindrical barrel, for example by threading, opposite the clamping flange. Such a plug 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 stressing member being arranged in the second recess.
[0023] Preferably, the pawn is made of a material resistant to friction, especially steel.
[0024] Preferably, the head has a cylindrical section on the bearing side and a hemispherical cap-shaped 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 element further comprises a rod connected to the head by the bearing surface, the internal cavity further comprising a third recess dimensioned to receive the rod by sliding, the stressing element being mounted around the rod and being arranged between a rod-side face of the bearing surface, called the 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 with 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 guide portion.
[0028] Preferably, the stressing element is an elastic stressing element 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 truncated conical 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 one particular embodiment, the munition comprises three devices forming a rear guidance interface regularly distributed angularly around the sabot.
[0034] Preferably, the shoe has 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 attached to the end of an arm of the rear support bearing.
[0035] The invention will be better understood upon reading the following description, which is made in light of the attached drawings, drawings in which:
[0036] represents a cross-sectional view of the device forming the rear guidance interface according to the invention;
[0037] represents a cross-sectional view of the connecting element of the laseul device;
[0038] is a perspective view of the device of the;
[0039] is a perspective view showing a device according to the invention mounted on the rear support bearing of a sabot of a munition, in the resting state;
[0040] is a cross-sectional view showing the mounting device on the sabot of a munition and located opposite the connecting cone;
[0041] is a view analogous to that of the, showing the device opposite the inner wall of the weapon tube; and
[0042] 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 range 52 of the sabot 5, as well as to guide the contact interface element 3, 4.
[0045] Referring to the figure, we can see that the connecting element 2 is in the form of a hollow sleeve generally comprising a fixing portion 20, a clamping portion 21, and a guide portion 22, and carrying a cap 23. The fixing portion 20, clamping portion 21, and guide portion 22 are formed as a single unit. The sleeve extends longitudinally along a longitudinal axis X1 from a first end 2a to a second end 2b.
[0046] The mounting portion 20 is dimensioned and configured to be received and secured in the projectile portion 5, 6. The mounting portion 20 is in the form of a cylindrical shaft extending along the longitudinal axis X1 of the socket from the first end 2a. This shaft has an external thread suitable for screwing 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 shaft 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 shaft and the clamping portion 21, the shaft has a narrowed section forming a V-groove 200 on the circumference of the shaft. 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 portion 20 carries a plug 23 at the first end 2b of the sleeve. The plug 23 is detachably fixed to the end region of the barrel opposite the clamping portion 21. In particular, the plug 23 has an external thread that engages with an internal thread of the barrel. This plug 23 has a narrow portion carrying the external thread and a wide portion. Both the narrow and wide portions have a cylindrical cross-section, with 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 fastening portion has a frustoconical shape, facilitating the tightening and loosening of the plug 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 the figure, when this connecting piece 7 is attached to the projectile portion 5, 6. This connecting piece 7 is known in itself and has, for each device 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 X1 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 bracket; a torque wrench is the appropriate tightening tool. Such a wrench ensures optimal fastening of the device without risk of loosening or damage.
[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 X1 of the sleeve and extending through the plug 23 and the fixing and clamping portions 20 and 21. This internal cavity opens on both sides of the sleeve at the first 2a and second 2b ends. Alternatively, the internal cavity could open only at the second end 2b, i.e., the flange side 21. The internal cavity includes first 220, second 221, and third 222 recesses. The first recess 220 is a cylindrical recess that extends 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 area 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 socket. The third recess 222 is formed through the plug 23. The diameter of the third recess 222 is less than the diameter of the second recess 221, and also less 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 load-forming member 4. The pad-forming member 3 is mounted to move in translation relative to the sleeve, coaxially with the longitudinal axis X1 of the sleeve, between a retracted position and a protruding position. The load-forming member 4 has the function of forcing the pad-forming member 3 towards its protruding position.
[0052] The pad-forming element 3 is in the form of a pin received and mounted to slide in the guide part 22. The mounting of the pad-forming 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 shaft 31, and a stem 32 formed as a single unit. The shaft 31 connects the head 30 and the stem 32. The head 30 has a cylindrical cross-section and a rounded free end in the shape of a hemispherical cap. The rounded end, designed 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 section corresponds approximately to the diameter of the first recess 220, such that the head 30 slides along the first recess 220. The bearing 31 has a cylindrical section with a diameter larger than the diameter of the cylindrical section of the head 30, and more specifically, the diameter of the bearing 31 corresponds approximately to the diameter of the second recess 221, such that the bearing 31 slides along the second recess 221.The longitudinal translational displacement of the bearing surface 31 towards the flange 21 is axially limited by the first internal end-of-stroke shoulder 223. 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 slides along the third recess 222. Therefore, 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 may 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, that is, not constrained towards its retracted position by the weapon tube 11, and therefore held in its protruding position by the activating member 4. In Figure 1, 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 element 4 is an elastic stressing element 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 element 4 is not limited to such an elastic element. This elastic element 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 element 4, coaxially with the longitudinal axis X1 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 X1 of the socket and the direction of the thrust force is outwards from the socket on the second end side 2b.
[0056] Thus, the device 1 according to the invention has a simple and robust structure comprising four parts: 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. In fact, 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 Figure 1, 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] On the figure, the munition 10 is shown placed 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 in place by a sabot 5 to compensate for the dimensional difference between the arrow 60 and the internal diameter of the weapon tube 11. This sabot 5 has a front support bearing 51 or a belt, of the caliber, suitable for closing the space 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 suitable for receiving the device 1 according to the invention in order to guide the sabot 5 in the weapon 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 rear guidance interface. 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 radially through openings 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 openings 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 gluing. The outside diameter of the rear portion 72 is approximately 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] During the loading of the ammunition 10 according to the invention, the forward portion 71 of the connecting piece 7 is positioned opposite the connecting cone 120. The pad-like element 3 of each device 1 is then pushed towards its protruding position by the actuating element 4, as shown in the figure, 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 separation of the casing 8 and 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, causes the actuating element 4, a compression spring type, to pre-stress and to crush, as shown on the.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 an automatic compensation of differences in circularity between the inner wall of the tube 11 and the munition 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 required for mounting the devices 1 according to the invention on the projectile part 5, 6 being a simple screwing of the devices 1 forming the rear guidance interface into the radial arms 520 of the sabot 5 directly after the installation of the connecting piece 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 as an indication and not as a limitation, and that modifications may be made without departing from the scope of the present invention.
Claims
Device (1) forming a rear guidance interface for ammunition (10), which ammunition (10) comprises 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 movably, 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. 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). Device (1) according to any one of claims 1 and 2, characterized in that the connecting element (2) is a sleeve comprising: - a cylindrical barrel with longitudinal axis (X1) 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 (X1) 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 (X1) of the barrel and opening outwards towards the outside of the sleeve on the side of the collar (21), the internal cavity constituting the guiding part (22). Device (1) according to claim 3, characterized in that the sliding member (3) is a pin comprising a head (30) integral with a bearing (31), the internal cavity of the sleeve is a stepped internal 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) at the end of travel formed between the first (220) and second (221) recesses, the stressing member (4) being arranged in the second recess (221). Device (1) according to claim 4, characterized in that the skating 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 stress 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. 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 of elastic polymer. 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. Munition (10) comprising a projectile part (5, 6) intended to be fired by a weapon having a chamber (12) communicating with a tube (11), the projectile part (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 or each device (1), the fixing part (20) being fixed in the sabot (5) radially to the axis (X2) of the projectile (6), and, in the protruding position, the pad-forming element (3) being intended to come into contact with the weapon tube (11). 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). Munition (10) according to claim 9, characterized in that the sabot (5) comprises at least one rear support bearing (52) axially spaced from a front support bearing (51), the rear support bearing (52) being constituted by 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).
Citation Information
Patent Citations
Sub-calibred projectiles with multiple supports
US20050016413A1