EP1151236B1 - Anti-recoil device with brake, brake compensator and recuperator - Google Patents

Abstract

The invention relates to anti-recoil devices for guns and martars.The anti-recoil device has a brake with a principal cabity which houses a principal piston pierced with holes. The small chamber of the brake is connected by an opening to a subisdiary chamber closed by a fluid-tight piston. The principal cavity and the subsidiary chamber are filled with a liquid whilst a gas under pressure, located on the other side of the fluid-tight piston with respect to the subsidiary chamber, tends to push back the subsidiary piston. A valve partially obturtes the holes of the principal piston, during the return to firing position, in order to brake that return.

Description

The present invention relates to anti-recoil devices for guns and mortars and more specifically the anti-recoil devices that comprise a parking brake and, associated with this brake, a compensator and a recuperator.

It is known to reduce the effects of the recoil of a gun or a mortar with a firing brake. It is known to add to the firing brake a compensator and a recuperator; German Patent DE 103 975 of the August 18, 1898 offers an anti-recoil device where a brake equipped with a compensator plays, in addition to its role of brake, a role of recuperator.

The device according to this patent can be described as being an anti-recoil device which includes a firing brake serving as recuperator and a compensator coupled to the brake by a conduit, the brake having a main cavity, a main piston pierced with holes and a main rod with an integral end of the piston and one end out of the cavity, the piston forming a barrier imperfect which subdivides the cavity into a small chamber in which passes the rod and a large chamber, the compensator having an auxiliary cavity, a sealed auxiliary piston, for delimit a secondary chamber in the annex cavity, and a system booster which acts on the auxiliary piston to tend to reduce the volume of the annex chamber, the device having its main cavity and its annex chamber filled with liquid, the conduit connecting between they the small room and the annex room and the system being intended to be used with the small room that increases volume during the recoil.

In the device according to DE 103 975, which covers the preamble features of the claim, so that the speed of movement of the main piston is slowed down during the return in the firing position, the adjoining chamber is not in direct contact with the conduit but via channels drilled in a fixed piston; the piston appendage slides between the fixed piston that surrounds and the side walls the surrounding cavity surrounding it; speed reduction is obtained through valves that close, but that in part, the channels when returning.

The assembly formed of the auxiliary piston and the fixed piston with its channels and its support, is complicated to realize, expensive and relatively fragile.

The present invention aims to avoid these disadvantages.

This is achieved, in particular by mounting the flap on the main piston of an anti-recoil device as defined in the claim 1.

• la figure 1, un frein de tir vu en coupe,
• les figures 2a à 2d les différentes façons d'utiliser un frein de tir,
• la figure 3, une vue en coupe d'un frein de tir associé à un compensateur,
• la figure 4, une vue en coupe d'un récupérateur,
• la figure 5, une vue en coupe d'un dispositif selon l'invention,
• les figures 6a à 6d, le dispositif de la figure 5 dans quatre positions qu'il occupe successivement lors d'un tir du système d'arme auquel il est incorporé.

The present invention will be better understood and other characteristics will appear with the aid of the description below and the figures relating thereto which represent:

• FIG. 1, a firing brake seen in section,
• FIGS. 2a to 2d the different ways of using a firing brake,
• FIG. 3 is a sectional view of a firing brake associated with a compensator,
• FIG. 4, a sectional view of a recuperator,
• FIG. 5, a sectional view of a device according to the invention,
• FIGS. 6a to 6d, the device of FIG. 5 in four positions which it occupies successively during a firing of the weapon system to which it is incorporated.

In the different figures, the corresponding elements are designated by the same references. It should be noted, moreover, that all figures correspond to weapon systems which, by convention, are arranged to fire munitions in a direction parallel to small sides of the leaf and facing the large left side of the leaf ; Moreover, to simplify the figures, the tubes used to draw ammunition and which will be said to be fire tubes in what follows, do not have been represented.

FIG. 1 is a schematic longitudinal sectional view a reverse brake. This brake comprises a cavity 1 filled with a liquid 4, a piston 2 which can move in a direction XX in the cavity and a rod 3 secured to the piston; the liquid 4 is usually oil. The cavity has a longitudinal axis XX parallel to the firing direction of the weapon system considered; this cavity is of constant section, generally circular. The stem is parallel to the direction XX and has its first end attached to the piston; it crosses the floor of the cavity through an opening whose watertightness is provided by a seal, so as to have its second end off of the cavity and to allow a displacement of the piston in the cavity, without loss of liquid. The piston defines two chambers in the cavity; these rooms are usually called small room for that, 11, located on the same side of the piston 2 as the rod 3 and large for the other, 12. The piston is pierced with holes, such as hole 20, the dimensions are calibrated to ensure the braking intensity desired: the smaller the total cross section of these holes, the smaller the resistance to fluid exchange between the two chambers is big.

In Figure 1 it is assumed that at the moment the brake is observed, the relative movement of the piston 2 with respect to the cavity 1 is the one in which the stem length is located outside the cavity increases while the volume of the small chamber decreases and that that of the large room increases; in Figure 1 the displacement of the rod with respect to the cavity is symbolized by a arrow D and the transfer of liquid that provoke, through the piston 2, room volume changes is symbolized by a arrow Dp.

The brakes can be used in four configurations different depending on whether the fire tube is attached to the rod or the wall of the cavity and that, during the recoil, the displacement of the stem relative to the cavity causes a decrease in the volume of the small room or an increase of this volume. Figures 2a at 2d illustrate these four configurations in simplified diagrams where the cavity 1 is drawn in section so as to show the piston 2 and 3. On these diagrams of the arrows, T, oriented from the right towards the left indicate the direction of fire and thus symbolize the fire tube; these Arrows are connected by a line segment in broken line, or to the stem or to the cavity depending on whether the stem or cavity is integral with the tube and therefore according to whether the cavity or the rod is integral with the support of the weapon system considered; an arrow D associated with the part of the brake attached to the fire tube Indicates the movement of this part of the brake during the recoil. In correlation with the arrow T associated with the moving part of the brake, a hatched rectangle, M, is associated with the fixed part of the brake, it symbolizes the support of the system weapon.

In the case of FIG. 2a, the cavity 1 is fixed and the recoil leads to a reduction in the volume of the small room; the stem 3 works in traction.

In the case of Figure 2b, the cavity is also fixed but hindsight increases the volume of the small chamber; the stem 3 then works in compression.

In the case of FIG. 2c, the rod 3 is fixed and the recoil leads to a reduction in the volume of the small room; the stem works in traction.

In the case of Figure 2d, the rod 3 is also fixed but hindsight increases the volume of the small chamber; the stem 3 then works in compression.

The displacement of the piston-rod assembly inside the cavity causes a variation in the volume available for the liquid in the big and the little room. Figure 3 shows how a compensator can be associated with a brake of the type of the one that has been described in Figure 1, to compensate for these variations in volume and, at the same time, compensate for changes in the volume of liquid due to thermal expansion.

The assembly according to FIG. 3 comprises a brake similar to that of Figure 1 except that it has an opening, A, in the wall of the cavity 1 in the vicinity of that of the two ends of the cavity which is located in the big room. This set includes also an auxiliary cavity 1 ', of longitudinal axis YY parallel to XX; a piston 2 'can slide in this cavity, where, with the help of a seal 20 ', it constitutes a tight barrier between one side a clearing house 13 and on the other side a room Annex 14. The clearing house is filled with the same liquid, 4, that the cavity 1 with which it is in communication through opening A. Annex room 14 is in communication with the amblant atmosphere by a hole V; this annex room serves as housing with a coil spring, R; this spring that creates pressure to inside the clearing chamber 13, absorbs, by action on the piston 2 ', the volume variations of the compensation chamber 13.

• un écoulement de liquide de la petite chambre vers la grande chambre en ralson de la diminution du volume de la petite chambre; une flèche Dp symbolise cet écoulement
• une augmentation du volume global disponible pour le liquide dans la cavité, du fait que le volume occupé par la tige dans la cavité diminue; il en résulte une augmentation de la pression du liquide dans la chambre 11 et, en concordance, un déplacement du piston 2' sous l'action du ressort R pour réduire le volume de la chambre de compensation; une flèche Dc symbolise ce déplacement du piston 2' et une flèche Dt symbolise l'écoulement résultant de liquide de la chambre de compensation 13 vers la grande chambre 12.

Thus when the displacement of the rod relative to the cavity, according to an arrow D, reduces the length of the rod 3 which is inside the cavity, it occurs

• a flow of liquid from the small chamber to the large chamber in proportion to the diminution of the volume of the small chamber; an arrow Dp symbolizes this flow
• an increase in the overall volume available for the liquid in the cavity, because the volume occupied by the rod in the cavity decreases; this results in an increase in the pressure of the liquid in the chamber 11 and, in concordance, a displacement of the piston 2 'under the action of the spring R to reduce the volume of the compensation chamber; an arrow Dc symbolizes this movement of the piston 2 'and an arrow Dt symbolizes the resulting flow of liquid from the compensation chamber 13 to the large chamber 12.

It should be noted that among other variants of assembly according to the FIG. 3, the annex chamber 14 may be without communication with the outside atmosphere and the spring can be replaced by a gas under pressure or the spring R can be located in the chamber of compensation and work in traction. Likewise he is by no means essential that the annex cavity 1 'has its axis YY parallel to the axis XX of the cavity 1; it can even be in direct mechanical connection with the cavity 1 only by a duct which, like the opening A according to the figure 3, would communicate the large room and the room of compensation.

The replacement in initial position of fire of a fire tube, after firing an ammunition and retreating during that shot, is usually provided by a hydro-pneumatic recuperator; the role of the recuperator is to store some of the energy of recoil for, then, to restore it in order to bring the tube back to the position initial.

FIG. 4 is a diagram of an exemplary embodiment of a such recuperator. This figure shows two cavities 1a, 1b axes longitudinal X'X 'and Y'Y' and constant sections; these cavities views in longitudinal section in FIG. 4 are joined together by a leads W near their first end; the first ends of the cavities 1a and 1b are closed while only the second end of the cavity 1b is closed.

In the cavity 1a can slide a piston 2a integral with a rod 3a of axis parallel to the axis X'X '; the axis X'X 'must be parallel to the recoil direction of the fire tube which is not an obligation for the axis Y'Y 'which can make any angle with the direction of recoil of the fire tube. The piston 2a is provided with a seal so as to constitute a tight barrier inside the cavity la; likewise the rod 3a passes through the first closed end of the cavity 1a by an orifice provided with a seal to seal the crossing.

In the cavity 1b a piston 2b can slide along the axis Y'Y '; this piston is provided with a seal so as to constitute a barrier between two chambers 15 and 16 which it delimits within this cavity. The space between the pistons 2a, 2b and which includes the inside of the conduit W and the chamber 15 is filled with a liquid 4 while the chamber 16 between the piston 2b and the second end of the cavity 1b is filled with a gas under pressure and that the face of the piston 2a to the opposite of the rod 3a is to the pressure atmospheric; the liquid is usually oil and the gas of nitrogen.

When ammunition is pulled the recoil is translated by a displacement of the rod 3a relative to the cavity la from a initial firing position; this relative displacement is symbolized by a arrow D; recoil Injects oil via line W and arrow Ds, in the space of the cavity 2b between the conduit W and the piston 2b. The piston moves back along the arrow Dr compressing the nitrogen contained in the chamber 16. Compressed nitrogen can then be relax, pushing the piston 2b which pushes oil towards the cavity la and therefore brings back the piston-rod assembly, 2a-3a, to the position initial firing defined by a stop not shown.

Again, as when the firing brake is used alone or with a compensator, the fire tube can be secured to either the rod 3 and then the cavities 1a, 1b are fixed, ie cavities 1a, 1b and the piston-rod assembly, 2a-3a, is fixed. In addition, it should be noted that cavities 1a, 1b have been shown separately in FIG. is not an obligation, they could be joined like the two Brake cavities with compensator of Figure 3.

As a variant to the recuperator according to FIG. 4, the gas under pressure of the cavity 16 can be replaced by a spring that works in compression during the recoil or by a spring in the cavity 15, this last spring working in traction during the recoil.

FIG. 5 is a longitudinal sectional view of a brake with compensator which is designed to play the role of recuperator. Has some improvements, not essential to its operation, this brake corresponds to the recuperator according to FIG. 4, in which the end of the cavity opposite to the stem would be obstructed, in which the piston 2a would be deliberately leakproof and in which the entire cavity 1a would be filled with liquid. However, to be able operate in recuperator the brake thus constituted must have its stem who works in compression during the retreat, that is to say, be in one any of the configurations illustrated in Figures 2b, 2d; these configurations are those where the recoil has the effect of compressing the gas or the spring put in place of the gas or stretch the spring which has been said about figure 4 that it could be placed in chamber 15.

In Figure 5 thus appear a main cavity 1 of axis XX, with a piston 2, a rod 3, a small chamber 11, a large chamber 12 and a secondary cavity 6 of axis YY, with a piston 60, a secondary chamber 61 in communication, by a orifice C, with the small chamber 11 and a compression chamber 62 filled with a pressurized gas 5. The piston 2 is rendered leaky through holes such as 20.

It should be noted the presence of a control rod 7 in the large chamber 12 and a hollow part in the piston-rod assembly 2-3 next to the rod 7. The rod 7 integral with the cavity 1 is profiled in truncated cone and penetrates more or less into the hollow part of the rod 3 according to the position of the piston 2 in the cavity 1. This control rod assembly-hollow part constitutes a system classic to get the most constant brake pressure possible throughout the retreat.

It is also worth noting, in the small room 11, in connection with the piston 2, a valve 21 provided with a return spring 22. The valve is pierced with holes such as 210 which have a section of the order four times smaller than the holes such as 20 and the spring 22 tends to press the valve 21 on the piston 2. As long as the valve is plated on the piston, each hole such as 210 opens into a hole such as 20 and vice versa. Or the valve 21 is pressed on the piston 2 as long as the pressure in the large chamber 12 is less than the pressure in the small chamber increased by the pressure exerted by the spring 21 on the valve; beyond that, the flap opens.

Figures 6a to 6d show the drawing of the brake with compensator of Figure 5 in a configuration according to Figure 2d that is to say with the fixed rod 3 and the movable cavities 1, 6; this is symbolized by a ground pin which bears the mark M1 in Figure 6a.

In addition a rubber damper occupies a position fixed; it is symbolized by a rectangle supported on a ground stud. These elements which bear respectively the references N and M2 on the Figure 6a determine a return, after recoil, in a firing position which will be called initial position: the position where cavities 1, 6 come into contact with the damper N.

When ammunition is fired, the fire tube attached to cavities 1, 6 drives the latter in its recoil. The cavities are in the initial position according to Figure 6a at the time of firing trigger; the recoil brings them to a rear position maximum shown in Figure 6c.

Figure 6b shows the brake as it stands, during the recoil fire tube, in an intermediate position between the initial position and the maximum rear position. An arrow D symbolizes the displacement of the cavities 1, 6 during the recoil; hindsight leads to a strong pressure increase in the large room 12 from where a opening of the valve 21 which allows a rapid passage of liquid from the large room to the small room 11; an arrow Dp symbolizes the flow of liquid through the piston 2. The increase pressure in the large chamber causes: - a flow of liquid, symbolized by an arrow Dr, from the small chamber to the secondary chamber 61 - a push on the piston 60 that comes compressing the gas enclosed in the compression chamber 62.

When the pressure increase due to recoil ceases, cavities 1, 6 are in the position illustrated in Figure 6c with the valve 21 which closes; the pressure in the chamber of compression 62 is maximum and will therefore push the piston 60 and by there even cause a reflux of liquid which leads to a displacement cavities 1, 6 in which the length of the rod 3 located at the interior of the cavity 1 decreases.

Figure 6d shows the brake as it is when returning in initial position; the drawing corresponds to an intermediate position and, in this drawing, the displacements are symbolized by an arrow D ' for the cavities 1, 6 and by two arrows Dr 'and Dp' for the liquid; these three arrows correspond, but with opposite directions, respectively to the three arrows D, Dr and Dp according to Figure 6b.

The return ends with the arrival of cavities 1, 2 in contact with the shock absorber N, that is to say when the brake has returned to the position shown in Figure 6a.

It should be noted that, thanks to the flap, the flow of liquid which goes from the small to the big room is reduced and so the speed displacement, when returning, is reduced; regulation that the brake brings to the speed of movement of the fire tube when the return is thus independent of the regulation that it brings to this speed during of hindsight.

Here again various variants can be proposed; in particular: - no use of a control rod and use of a conventional piston-rod assembly as illustrated in Figures 1 and 3 - replacement of the gas by a spring working in compression in the compression chamber 62 or in traction in the chamber secondary 61, the chamber 62 then being in connection with the atmosphere - secondary cavity 6 without common wall with the primary cavity 1 and / or whose longitudinal axis has a direction different from that of the longitudinal axis of the main cavity - piston not pierced with holes but having a section smaller than that of the cavity so as to allow the exchange of liquid, at its periphery, between the small and the big room.

Claims (3)

1. Anti-recoil device comprising a fire brake serving as a recuperator and a compensator coupled to the brake by a duct (C), the brake comprising a principal cavity (1), a principal piston (2) pierced with holes (20) and a principal rod (3) with one end integral with the piston and one end outside of the cavity, the piston forming an imperfect barrier which subdivides the cavity into a small chamber (11) inside of which the rod passes and a big chamber (12), the compensator comprising a subsidiary cavity (6), a subsidiary fluid-tight piston (60) to delimit a subsidiary chamber (61) inside the subsidiary cavity, and a return system (62-5) which acts on the subsidiary piston in such a way as to tend to reduce the volume of the subsidiary chamber, the device having its principal cavity and its subsidiary chamber filled with liquid, the duct (C) interconnecting the small chamber (11) and the subsidiary chamber (61) and the system being provided in order to be used with the small chamber which increases in volume during the recoil, characterized in that the subsidiary chamber constitutes an empty space strictly delimited by the subsidiary piston and the subsidiary cavity and in that a valve (21) is mounted on the assembly constituted by the principal piston and the rod in order to obturate the holes partially when it is closed and to open when the pressure in the big chamber (12) exceeds that in the small chamber by a predetermined value.
2. Device according to Claim 1, characterized in that it comprises a control rod (7) integral with the principal cavity (1) and disposed inside the big chamber (12) and in that the assembly constituted by the principal piston (2) and the principal rod (3) has a hollow section, facing the control rod (7), and into which the control rod penetrates more or less deeply depending on the position of the principal piston in the principal cavity.
3. Device according to Claim 1, characterized in that the return system is a fluid-tight chamber (62) filled with a gas (5), this chamber filled with a gas being limited by the subsidiary piston in the subsidiary cavity opposite the subsidiary chamber.

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