EP0687884B1 - Sleeve for preventing bowing - Google Patents

Description

The technical field of the present invention is that of anti-arching sleeves for artillery tube heavy gauge.

Modern design of artillery tubes involves the use of an anti-arcuate sleeve, i.e. an additional part cooperating with the tube to avoid its curvature. Indeed, the tube which is used to launching projectiles is a relatively long piece attached to the mount at one end. She must therefore resist in particular the action of its own weight, to the constraints resulting from the cannon shot and weather conditions.

Three techniques are used to achieve currently the anti-arcuate sleeves: by molding, by mechanical welding and filament wound, followed by each time of particular machining to ensure after assembling the alignment of the spans. So it's a significant drawback with regard to the dimensions of the parts to be handled. On the other hand, taking into account recoil accelerations brought into play by cannon fire, the dimensioning of the anti-arcuate sleeves means that the length of these for outfit issues mechanical, or to increase the thickness of the walls, therefore suspended mass.

The main reason for the anti-arch sleeve is function of limiting the arcuate, i.e. the deformation of the tube, due to external conditions: rain, heating for example, which cause a change in the tube temperature in a direction other than that of its axis. So a temperature gradient between the upper and lower part of the tube causes a deformation of it and affects the shot accuracy.

Patent FR-A-1 445 546 describes a device to prevent the arching of a cannon according to which one has an envelope around the tube at a certain distance from this one. This creates a fluid mattress within which temperature differences cause phenomena convection which restore thermal homogeneity. However, no specific structure is described for fix this envelope on the tube.

The European Patent Application EP-0 183 432 of which the account is taken from the preamble of claim 1, describes a thermal insulation sleeve made up of two half-shells assembled by means of connection and fixed to the barrel of the weapon by rings. The sleeve is made from a rigid plastic. However, such a sleeve is not enough efficient for a large caliber artillery tube.

The object of the present invention is to design an arcuate sleeve for a tube large caliber artillery to overcome the disadvantages of the prior art while reducing its mass and minimizing the temperature gradient between the two ends of the tube.

To this end, the invention provides a sleeve anti-bending for large caliber artillery tube, consisting of an envelope in the form of two half-shells assembled by a connection means, said envelope surrounding the tube at a distance over a length substantially equal to that of the emerging part of the tube and being fixed by means of a front ring mounted on the near the free end of the tube and a ring rear mounted at the tube smoke box, characterized in that each half-shell is provided with external and / or internal reinforcement means.

According to an exemplary embodiment, the means of internal reinforcement consists of a shaped profile from T.

According to an exemplary embodiment, the means of external reinforcement consists of a section profile straight Ω-shaped.

According to a characteristic of the invention, each ring is provided with a groove for receiving the envelope.

• les deux demi-coquilles sont munies au niveau de leurs bords adjacents d'un moyen de connexion constitué par un profilé en forme de H, par exemple, et
• chaque demi-coquille est munie de percements pour assurer la circulation de l'air entre l'espace interne délimité par les demi-coquilles et le tube, et l'extérieur.

According to other characteristics of the invention:

• the two half-shells are provided at their adjacent edges with a connection means constituted by an H-shaped profile, for example, and
• each half-shell is provided with openings to ensure the circulation of air between the internal space delimited by the half-shells and the tube, and the outside.

According to yet another characteristic of the invention, the anti-arcuate sleeve comprises at least one intermediate ring disposed substantially at the level of the middle part of the envelope, this ring being provided with on either side of a groove receiving the end of the two envelope elements, this ring being applied directly on the tube by clamping.

According to another characteristic of the invention, an insulating washer, for example in rubber, is arranged between the intermediate ring and the tube.

According to a preferred embodiment, two intermediate rings are provided, each ring intermediate being provided with longitudinal holes making communicate the subsets delimited by the envelope, the front and rear rings and the ring (s) intermediaries.

Generally speaking, each half-shell presents in section a semi-circular profile, the envelope has a conical profile with a large base constituted by the rear ring, and the half-shells, the profiles in H, L and Ω are made using sheets using a folding technique.

An advantage of the present invention lies in the implementation of simple techniques of manufacturing excluding any molding operation, machining or mechanical welding, leading to a lower manufacturing costs.

Another advantage of the invention lies in the fact that the sleeve resists recoil accelerations greater than 5000 m / s ² .

Yet another advantage of the invention is in the possibility of partial or total replacement of the sleeve without affecting the characteristics of the tube itself.

Yet another advantage of the invention is in that elements of the sleeve have a identical structure.

• la figure 1 est une vue d'un premier mode de réalisation du manchon selon l'invention,
• la figure 2 est une vue d'un second mode de réalisation du manchon selon l'invention,
• la figure 3 est une vue éclatée en perspective d'une partie de la moitié supérieure du manchon du second mode de réalisation de la figure 2,
• la figure 4 est une vue en perspective de la moitié inférieure du manchon,
• la figure 5 est une vue en coupe d'un collier, et
• la figure 6 est une vue en coupe transversale de l'enveloppe.

Other characteristics and advantages of the invention will be better understood on reading the additional description which follows given in relation to the drawings in which:

• FIG. 1 is a view of a first embodiment of the sleeve according to the invention,
• FIG. 2 is a view of a second embodiment of the sleeve according to the invention,
• FIG. 3 is an exploded perspective view of part of the upper half of the sleeve of the second embodiment of FIG. 2,
• FIG. 4 is a perspective view of the lower half of the sleeve,
• FIG. 5 is a sectional view of a necklace, and
• Figure 6 is a cross-sectional view of the envelope.

Figure 1 shows an artillery tube 1 provided a smoke box 2, terminated by a muzzle brake 3 forward. Tube 1 conventionally extends the chamber from the barrel and need not be described more fully. he presents however a general frustoconical form between the smoke box 2 and the muzzle brake 3, the large base being located towards the smoke box. At the level of intermediate part between the smoke box 2 and the brake mouth 3 or else the free front end if the tube 1 does not have a muzzle brake, it is well known to have an anti-arcuate sleeve 4 whose primary objective is to limit detrimental tube deformations weapon performance. The longer the length of this intermediate part is important plus the anti-arcuate sleeve must be efficient, which results in a increase in mass of the projecting part of the tube. The reversing accelerations brought into play further aggravate the disadvantages linked to the mass and deteriorate the holding mechanics of the anti-bending tube-sleeve assembly.

According to the invention, the anti-arcuate sleeve 4 includes a rear ring 5 and a front ring 6 between which is arranged a spacer 7. The ring rear 5 is guided on a surface made on the box smoke 2. Front ring 6 is held in a groove practiced on the tube. You can fix the front ring 6 to any distance from the rear ring 5 depending characteristics sought by those skilled in the art. According to the invention, it is preferred to fix the front ring 6 as close as possible to the muzzle brake 3. The casing 7 is placed at a distance from the tube 1 and can surround totally or partially said tube. According to the figure 1, the casing 7 completely surrounds the tube 1 and has a general frustoconical shape analogous to that of the tube, this embodiment being chosen for for convenience. Envelope 7 consists of two half-shells 8 and 9 joined by means of 10 H-shaped connection at their edges adjacent, and held by clamps 11. Each half-shell 8 and 9 can be reinforced by means external and / or internal reinforcement. Figure 1 shows a external reinforcement means 12 consisting of a profile with Ω-shaped cross section applied against the surface outer of each half-shell trapping the collars 11, by gluing, riveting or welding. The length of this profile is substantially equal to that of the half-shell, pressing against the two rings 5 and 6. These reinforcements increase the resistance of envelope 7 at acceleration of recoil and absorb forces created by the inertia of the anti-arcuate sleeve.

The rear 5 and front 6 rings include each a circular groove on their lateral face in look of the envelope and in which is housed at minus the corresponding end portion of the casing 7. The groove 24 of the rear ring 5 is visible in Figures 3 and 4, and the groove 28 of the front ring 6 is visible in Figure 4.

The position of the two half-shells 8 and 9 can be arbitrary compared to tube 1. In particular, we can arrange the two half-shells 8 and 9 to the upper and lower parts of the tube 1. The lower half-shell 8 can be provided with holes 13 promoting air circulation.

Another embodiment is shown in Figure 2 where we see that each half-shell is itself carried out in two parts.

This variant can be implemented in especially when the tube 1 is very long and of large caliber undergoing very strong accelerations recoil (6000 g).

The spacer 7 then consists of two elements 7a and 7b in the extension of one another. Element 7a itself consists of two half-shells 8a and 9a joined by collars 11, while element 7b itself consists of two half-shells 8b and 9b joined by necklaces 11. For fix the two elements 7a and 7b together, the ring rear 5 of element 7b is guided on the ring front 6 of element 7a, this ensuring coaxial guidance elements 7a and 7b. Intermediate rings 14 and 15 have bearing faces on which come rely on the two elements 7a and 7b. As in fashion of previous embodiment, each element 7a and 7b includes connection elements 10a and 10b for connecting the two half-shells 8a, 9a and 8b, 9b constituting each element, and reinforcing means 12a and 12b of Ω-shaped cross section. Finally, the half-shells upper 9a and 9b have holes 16 allowing air to escape from the top of the sleeve without allowing the water to runoff to enter. These openings have a smaller diameter than the holes 13 in the figure 1, which allow them to quickly evacuate everything liquid on board when crossing a river.

Figure 3 shows in more detail the half-shell 9a of element 7a of the envelope of the Figure 2, the constituent parts of which are shown in an exploded view. Concretely, we finds the rear ring 5, the half-shell 9a and the intermediate ring 14. In this embodiment, the half-shell 9a is reinforced by a profile 12a of Ω-shaped cross section in projecting view and by a profile 12a of straight section in the shape of Ω external side on the one hand, and by two T-shaped profiles 18 and 19 internal side on the other hand. Half shells 8a and 9a of element 7a are joined to using the two connection means 10a on which notches 20 can be made to cooperate with lugs 21 projecting at the edge of said half-shells. Thus, any relative displacement of the half-shells forbidden. In Figure 3, we can still see that the intermediate ring 14 is isolated from the tube 1 by a washer 22, for example made of rubber. This is for example bonded to the intermediate ring 14 and prohibits the transmission of deformations unavoidable from tube 1 to anti-arc sleeve 4 and reciprocally. The same is true of the ring intermediate 15 when the latter is used.

In Figure 4, there is shown an element 7a of the envelope and more particularly the half-shell 8a, the constituent parts of which are assembled. We sees that the half-shell 8a is provided with holes 13 large diameter for the evacuation of fluids during operation, of the reinforcing profile 12a projecting from the side external and T-shaped profile 19 on the internal side, two other sections 12a and 18 not being shown. The half-shell 8a or 8b consists of a part single applied to the intermediate rings 14 and 15. In this figure 4, we see that the rear ring 5 is provided with a groove 24 in which the half-shell engages 8a, the end of the profile 19 coming to bear against the edge of this groove. Each ring intermediate 14 or 15 receives a washer 22 in rubber. This washer can be placed in a groove in the thickness of the ring. Each intermediate ring has a notch 25 receiving the protruding edge 26 of the profile 19. The intermediate rings 14 and 15 are provided with longitudinal holes 27 to make communicate the subsets delimited by the envelope. We can also see that the front ring 6 has a groove 28 receiving the half-shell 8b and the end of the profile 19. The male part 29 has also been shown and the female part 30 of the necklaces 11 bringing together the half-shells between them, for example using a screw.

To further reduce the mass of the anti-arch sleeve, the weakly requested parts 14, 15, 5 and 10a can be made of aluminum alloy and plastic material. The solution according to the invention allows to increase the length usually allowed on tubes for anti-bending sleeves of about 1.50 m all reducing the mass by more than 20%.

On the other hand, we understand that the solution used in the invention makes it possible to maintain a layer air around the tube which is neither subjected to radiation neither wind nor precipitation. Homogeneity of this layer of air over the entire length of the tube is provided by the holes 13 and 16 of the half-shells and openings 25 of the intermediate rings 14 and 15. The 16 holes will be, given their position on the upper generator of the half-shell, sufficiently small so as not to let rainwater enter being large enough to allow an exchange of air to the outside, for example with a diameter of around 2 mm. The holes 13 will be, taking into account their position on the lower generatrix of the half-shell, large enough to allow, when crossing a ford, rapid evacuation of water that got into the anti-arc sleeve during of the maneuver. We can for example adopt a surface cumulative lower holes 13 equal or slightly greater than that of the upper holes 16 for ensure, inside the anti-arcing sleeve, a current of air which will have the effect of minimizing the gradient of temperature between the upper generator and the lower generator of the tube.

Figure 5 shows in section the ring intermediate 14 positioned on the tube (not shown) by means of the washer 22, provided with the holes 25 Communication. The half-shell 8a is applied to the outer surface of this ring as explained previously. The half-shell is engaged in the profiled in H 10 and is provided on its external surface with omega 12 profiles and 29 male parts and female 30 forming a connection collar 11. The half-shell complementary also includes these same elements. Each collar 11 has a welded tab 40 on the outer surface of the half-shell. This leg 40 receives the male or female part as the case may be. During assembly, the corresponding half-shells are placed facing each other by matching the male parts and female whose connection is ensured for example by screwing.

In Figure 6, there is shown a section transverse of a half-shell 8a for example on which the two reinforcements have been reported to on the outside 12a in omega on the external side and 19-shaped reinforcements T internal side. We also see the way to connection 10 H-shaped from half-shell 8a to corresponding half-shell not shown.

Claims (15)

1. A thermal sleeve for a large-calibre artillery barrel (1), formed of an envelope (7) in the form of two half-shells (8, 9) assembled by connection means (10), said envelope enclosing the barrel at a certain distance and for a length substantially equal to that of the emergent part of the barrel and being fastened by means of a front ring (6) mounted in the vicinity of the free end of the barrel (1) and a rear ring (5) mounted level with the smoke extractor (2) of the barrel, characterised in that each half-shell (8, 9) is fitted with external (12; 12a, 12b) and / or internal (18, 19) reinforcement means.
2. A thermal sleeve according to Claim 1, characterised in that the internal reinforcement means (18, 19) are formed by a T-shaped part.
3. A thermal sleeve according to Claims 1 or 2, characterised in that the external reinforcement means (12; 12a, 12b) are formed by a part having a Ω-shaped cross section.
4. A thermal sleeve according to any one of Claims 1 to 3, characterised in that each ring (5, 6) is fitted with a groove (24, 28) to accommodate the envelope (7).
5. A thermal sleeve according to any one of Claims 1 to 4, characterised in that the two half-shells (8, 9) are fitted at their adjacent edges with connection means (10).
6. A thermal sleeve according to Claim 5, characterised in that the connection means (10) are formed of an H-shaped part.
7. A thermal sleeve according to any one of Claims 1 to 6, characterised in that each half-shell (8, 9) has perforations (13, 16) to ensure the free circulation of air between the inner space delimited by the half-shells and the barrel, and the exterior.
8. A thermal sleeve according to any one of the above Claims, characterised in that it incorporates at least one intermediate ring (14, 15) positioned substantially at the median part of the envelope (7), this ring being fitted on either side with a groove (24, 26) accommodating the end of the two elements (7a, 7b) forming the envelope.
9. A thermal sleeve according to Claim 8, characterised in that the intermediate ring (14, 15) is applied directly to the barrel by clamping.
10. A thermal sleeve according to Claim 9, characterised in that an insulating washer (22), for example made of rubber, is placed between the intermediate ring (14, 15) and the barrel (1).
11. A thermal sleeve according to any one of Claims 8 to 10, characterised in that it comprises two intermediate rings (14, 15).
12. A thermal sleeve according to any one of Claims 8 to 11, characterised in that each intermediate ring (14, 15) is being perforated with longitudinal holes (25) making the sub-assemblies delimited by the envelope (7) communicate with the front (6) and rear (5) rings and the intermediate ring or rings (14, 15).
13. A thermal sleeve according to any one of Claims 1 to 12, characterised in that each half-shell (7) has a semi-circular cross section
14. A thermal sleeve according to Claim 13, characterised in that the envelope has a conical profile whose wide base is formed by the rear ring (5).
15. A thermal sleeve according to any one of Claims 1 to 14, characterised in that the half-shells, the H-shaped (10), T-shaped (18, 19) and Ω-shaped (12; 12a, 12b) parts are made using metal sheets employing a bending technique.

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