EP0321345B1 - Breech block for an artillary cannon - Google Patents

Abstract

The invention relates to a breech wedge for artillery cannon, of a type that includes means for supporting a primer-cartridge magazine that is driven in translation and rotation under the control of an assembly consisting of a rack and pinion. This first pinion is mounted on a shaft supporting a second pinion, which cooperates with a second rack integral with a fork sliding on the wedge. A control lever pivots on the breech sleeve and supports a roller, which cooperates with a groove in the fork in such a way as to slide the fork on the breech wedge. A second roller cooperates with a groove in the wedge in such a way as to cause the wedge to slide on the breech sleeve.

Description

The present invention relates to a breech wedge for artillery cannon, of the type comprising means for supporting a barrel with a stuffing box, the translation and rotation of said barrel being controlled by a pinion-rack assembly.

Such breech wedges are used in cannons intended to fire munitions comprising on the one hand a projectile, and on the other hand a propellant charge contained in a gargoyle or a combustible case. The charge is ignited by means of a choke placed in a chamber formed at the rear of the breech wedge, and in communication by a light channel with the propellant charge placed at the entrance of the barrel. To increase the rate of fire, the nipples are mounted on barrels allowing to bring into the chamber each shot fired, a new nipple not yet consumed.

Document FR-A-2,464,451 describes a cylinder head wedge of the type mentioned above. The pinion-rack assembly is actuated by a lever secured to the pinion and a cam secured to the recoil slides of the weapon. Furthermore, the striker is carried in this document by a carriage sliding on the breech corner and abutting on the sleeve in the percussion position, or releasing the gland holder barrel in the open position, using a T-slot system inclined with respect to the direction of movement of the corner. Finally, the light channel is inclined and relatively long, and it does not emerge in the center of the shooting plate.

Although generally satisfactory, this breech wedge has a number of drawbacks.

First of all, many parts are moving, and the sliding system of the carriage leads to delicate machining. Finally, asymmetric ignition generates pressure peaks causing ballistic dispersions.

The present invention seeks to overcome these drawbacks by providing a breech wedge in which the movements of the barrel are controlled directly by the translation of the wedge, without requiring an external mechanical part. It also aims to simplify the mechanism for holding the choke and percussion.

To this end, the subject of the invention is a breech wedge for an artillery cannon, of the type comprising means for supporting a barrel with a stuffing box, the translation and rotation of said barrel being controlled by an assembly consisting of a first pinion and a first rack, characterized in that said first pinion is mounted on a shaft supporting a second pinion arranged to cooperate with a second rack fixed to a fork mounted sliding on said corner, a control lever being pivotally mounted on the cylinder head sleeve and supporting a first roller arranged to cooperate with a groove of the fork so as to cause the sliding of the fork on the breech wedge, and a second roller arranged to cooperate with a groove in the wedge so as to cause the wedge to slide on the breech sleeve.

Thus, the same lever which causes the movement of opening and closing of the cylinder head, also makes it possible to ensure the rotation of the barrel which carries the threads.

The second groove may in particular comprise a circular part centered on the axis of rotation of the control lever, so that the breech wedge remains substantially fixed relative to the breech sleeve during the rotation of the threaded barrel.

The two rollers can be mounted coaxially on the control lever, the parts of the grooves of the fork and of the cylinder head corner traversed by the rollers during the sliding of the corner on the cylinder head sleeve being superimposed when the fork is in its position where the The threaded barrel is engaged on the breech wedge.

In a particular embodiment, the breech wedge according to the invention comprises a striker carrying carriage slidingly mounted on the wedge between a first position where the striker is located opposite a nipple to be struck, and a second position where the carriage releases the gland holder barrel, stops being provided on the cylinder head sleeve to cause the carriage to move relative to the corner, when the corner is displaced relative to the sleeve.

More particularly, the carriage may be integral in translation with a rod sliding in a bore of the cylinder head sleeve, a stop of the rod cooperating with an abutment of the sleeve to bring the carriage into its said first position, when the closing of the cylinder head, and a stop of the carriage cooperating with another stop of the sleeve to bring the carriage into its said second position when the cylinder head opens.

The carriage may advantageously include an inclined surface arranged to cooperate with a corresponding surface of the nipple holder barrel to crimp the nipple in its housing, the resulting translational movement for said first rack, being absorbed by a torsional prestress of the 'support shaft of said first and second pinions.

The actuator of the striker of the breech wedge according to the invention can in particular be pivotally mounted on the wedge in a location such that it is only likely to actuate the striker when the carriage is in its said first position.

As the firing member is mounted on the cylinder head sleeve, this results, when the cylinder head is open, a double misalignment of the percussion chain, on the one hand between the cylinder head sleeve and the cylinder head corner, and on the other hand between the breech corner and the striker carriage.

• la figure 1 est une vue de derrière d'un coin de culasse selon l'invention,
• la figure 2 est une vue en coupe selon la ligne II-II de la figure 1,
• la figure 3 est une élévation vue de gauche, partiellement en coupe selon la ligne III-III de la figure 1.
• les figures 4a et 4b sont des vues partielles de dessus dans deux positions de la fourchette,
• la figure 5 est une vue de dessus du levier de commande, et
• la figure 6 est une vue de côté de ce levier, partiellement en coupe.

A particular embodiment of the invention will now be described, by way of nonlimiting example, with reference to the appended drawings in which:

• FIG. 1 is a rear view of a cylinder head corner according to the invention,
• FIG. 2 is a sectional view along the line II-II of FIG. 1,
• FIG. 3 is an elevation seen from the left, partially in section along the line III-III of FIG. 1.
• FIGS. 4a and 4b are partial top views in two positions of the fork,
• FIG. 5 is a top view of the control lever, and
• Figure 6 is a side view of this lever, partially in section.

The breech wedge 1 is mounted in a known manner sliding on the breech sleeve 2, partially shown in broken lines in FIG. 1.

A mounting system 3 makes it possible to support a nipple holder barrel 4, in such a way that a nipple is placed in a nipple holder chamber 6 communicating with the barrel of the weapon by a light channel 7.

A pinion 8 and rack 9 system makes it possible to roll back the barrel and to rotate it with each shot fired.

Such an arrangement is described in the aforementioned document FR-A-2,464,451. Note, however, that in the breech corner according to the invention, the light channel extends along the axis of the barrel of the weapon.

In the present case, the pinion 8 is mounted at the lower end of a torsion shaft 10 supporting at its upper part another pinion 11 (FIG. 3). The shaft 10 is rotatably mounted in the cylinder head corner 1, prestressed so as to tend to bring the rack 9 back.

At its upper part, the breech wedge 1 supports a fork 12 slidably mounted using two sets of grooves and T, 13.

The fork 12 also includes a rack 14 arranged to cooperate with the pinion 11.

The sliding movement of the fork 12 with respect to the cylinder head corner 1 is controlled using a lever 15 shown in detail in FIGS. 5 and 6, and shown diagrammatically in three different positions by the dashed lines 15a, 15b and 15c in Figures 4a and 4b.

One end of the lever 15 comprises a sleeve 16 in which a grooved bore 17 is formed capable of cooperating with a corresponding grooved shaft mounted for rotation on the cylinder head sleeve. Only the axis 18 of this tree is shown in Figures 4a and 4b.

The lever 15 also carries at its other end, two coaxial rollers 19 and 20.

The roller 20 is engaged in a Z-shaped groove in the cylinder head corner 1 comprising a first rectilinear part 21, a circular part 22 centered on the axis 18, and a second rectilinear part 23.

The roller 19 is engaged in a rectilinear groove 24 of the fork 12.

In the position of FIG. 4b, the part 23 of the Z-groove and the groove 24 are superimposed.

The breech wedge 1 also supports a carriage 25 slidably mounted using a T-slot, 26. The striker 27 is pivotally mounted on the carriage 25 via the axis 28 (Figure 3 ).

A slider 29 is also slidably mounted on the cylinder head corner 1, using T-shaped grooves 30, and is made integral with the carriage 25 by a projecting member 31. The slider 29 is also secured with a rod 32 mounted sliding in a bore 33 of the cylinder head sleeve 2.

The rod 32 carries at its end opposite to the slide 29, a nut 34 acting as a stop to cooperate with an abutment surface 35 of the cylinder head sleeve 2.

Likewise, the carriage 25 has an abutment surface 36 capable of cooperating with a corresponding abutment surface 37 of the cylinder head sleeve 2.

An actuating member 38 of the striker 27 is pivotally mounted on the breech wedge about an axis 39. The member 38 is rotatably connected to a shaft 40.

A rod 41 is mounted in a bore in the cylinder head corner 1 to move in translation against the action of a spring 42. Unecame 43 makes it possible to transform the translational movement of the rod 41 into a rotational movement of the shaft 40, and therefore to operate the actuator 38 of the striker.

The breech wedge being in its open position shown in FIG. 4a, with the lever 15 in its position 15a, this lever is rotated in the direction of the arrow F1, the roller 20 moving in the part 22 of the groove in Z.

The roller 19 cooperating with the groove 24 therefore causes the fork 12 to move relative to the cylinder head corner 1 in the direction of arrow F2. This displacement causes the pinion 11 to rotate in the direction of arrow F3 by means of the rack 14. There follows a rotation of the shaft 10 and of the pinion 8 which, by means of the rack 9 causes the installation of a choke in the chamber 6, as described in the aforementioned document FR-A-2,464,451.

The movement of the lever 15 continuing as shown in 15b in FIG. 4b, the roller 19 continues its race in the groove 24 while the roller 20 engages in the part 23 of the Z-groove in the breech wedge 1. It follows that this cylinder head corner moves in the direction of arrow F4 to close the cylinder head. This closure is obtained when the lever 15 reaches its position 15c shown in FIG. 4b, the breech wedge 1 then being located with respect to the breech sleeve 2 in the position shown in FIGS. 1 and 2.

During this second phase of the movement, the stops 34 and 35 came into contact so that the carriage 25 which was initially relative to the breech wedge 1 in position 25 ′ shown in phantom in Figure 1, is come into its position in solid lines, with the striker 27 having its upper part facing the chamber 6 and its lower part facing the actuating member 38. During this same movement, the head of the rod 41 came opposite a percussion member mounted on the breech wedge 2, so that the percussion chain is aligned.

If, in this position, a shock is exerted on the rod 41 in the direction of the arrow F5, this rod sinks against the action of the spring 42, thus causing the rotation of the shaft 40 and that of the member actuation 38. This switches the striker 27 which causes the ignition of the choke, and consequently the propellant charge.

It will be noted that the front end of the nipple is crimped in the conical end part of the chamber 6, due to the cooperation of an inclined surface 44 of the carriage 25 with an inclined surface 45 of the nipple holder barrel 4 This crimping results in a twisting of the shaft 10 and results in perfect positioning of the chuck in its housing.

After the shot has been fired, the lever 15 is first returned to its position 15b, which causes a displacement of the breech wedge in the direction of arrow F6, of FIG. 1.

As a result of friction, the rod 32 slides in the bore 33, the carriage 25 thus being driven with the breech wedge 1. When its abutment surface 36 comes into contact with the abutment surface 37 of the breech sleeve 2, the carriage 25 is immobilized with respect to this sleeve, so that, the breech wedge continuing its movement in the direction of arrow F6, the carriage 25 is brought back with respect to this breech wedge in its position 25 ′.

It will be noted that, from the start of the movement of the bolt wedge, the percussion chain is misaligned due to the lateral displacement of the rod 41. As soon as the abutment surfaces 36 and 37 are in contact, the percussion chain is doubly misaligned due to the fact that the lower part of the striker 27 is no longer facing the actuating member 38.

When the opening movement of the breech wedge 1 is complete, the lever 15 causes the fork 12 to move in the opposite direction to the arrow F1, and, by a reverse movement to that described previously, the extraction and rotation of the stuffing box barrel.

Claims (7)

1. Artillery tube breech wedge of the type including means for supporting a primer-cartridge magazine (4), the translation and rotation of said magazine being controlled by a first pinion (8) and first rack (9), characterised by the fact that said first pinion is mounted on a shaft (10) supporting a second pinion (11) that cooperates with a second rack (14) integral with a fork (12) mounted sliding on said wedge, with a control lever (15) mounted pivoting on the breech sleeve (2) and supporting a first roller (19) arranged to cooperate with a groove (24) in said fork so as to cause the fork to slide on the breech wedge, and a second roller (20) arranged to cooperate with a groove (21, 22, 23) in the wedge of the breech to cause the wedge of the breech to slide on the breech sleeve.
2. Breech wedge according to claim 1, characterized by the fact that the second groove includes a circular part (22) centered on the axis of rotation (18) of the said control lever, so that the breech wedge remains roughly stationary with respect to the breech sleeve during the rotation of the primer-cartridge magazine.
3. Breech wedge according to claim 1 or 2, characterized by the fact that the said first and second rollers are coaxial, the parts of the grooves in the fork and breech wedge in which the rollers ride as the wedge slides over the wedge sleeve are superposed when the fork is in position where the primer-cartridge magazine is engaged on the breech wedge.
4. Breech wedge according to anyone of claims 1 to 3 characterized by the fact that it includes a pin carriage slider (25) sliding on the wedge between a first position where the pin is facing a primer to be fired and a second position (25') where the slider frees the primer-cartridge magazine, with stops (35, 37) being provided on the breech sleeve to move the slider with respect to the wedge when the wedge moves with respect to the sleeve.
5. Breech wedge of claim 4, characterized by the fact that the said slider is integral in translation with a rod (32) sliding in a bore (33) of the breech sleeve, a stop (34) of the rod cooperating with a stop (35) of the sleeve to bring the slider into its said first position when the breech is closed, ans a stop (36) on the slider cooperating with another stop (37) on the sleeve to bring the slider into its said second position when the breech is open.
6. Breech wedge according to claim 4 and 5, characterized by the fact that said slider includes an inclined surface (44) arranged to cooperate with a corresponding surface (45) on the primer-cartridge magazine to crimp the primer into its lodging, while the resulting translational motion for said first rack is absorbed by a torsional prestress of the shaft supporting said first and second pinions.
7. Breech wedge according to anyone of claim 4 to 6, characterized by the fact that it includes a pin actuating element (38) mounted to pivot on the wedge at a position such that it is possible to actuate the pin only when the slider is in its said first position.

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