The invention will become more apparent from the following description of a particular embodiment, such description made in reference to the appended drawings, in which:
a, 2b and 2c show three success steps in the deployment and implementation of the weapon system according to the invention,
a, 3b and 3c partially show the deployed weapon along three viewing axes,
a and 5b are explanatory schemas showing the kinematics of the arms.
The vehicle is a light vehicle (mass less than 5 tons), and here it is a 4×4 HMMWV (American Motors registered trademark) whose rear has been emptied out to receive the weapon system.
The weapon system 2 incorporates a canon 3 equipped with a muzzle brake 4, such cannon mounted on a cradle 5.
The structure of the cannon is not the subject of the present invention. The cannon classically comprises a breech ring 3a and a hydraulic recoil brake 3b connecting the cannon to the cradle (see
The cradle 5 is mounted able to pivot around a shaft 3c on a fork 6, thereby enabling the weapon to be laid in elevation. The cradle is classically made to pivot with respect to the fork by an electric motor 24 (see
The fork 6 is, furthermore, mounted on a turntable 7 (for example with ball bearings) which can be seen more particularly in
The laying motors 24 and 25 are powered by an electric generator, not shown. A hydraulic generator may also be implemented that associates hydraulic motors or jacks.
The turntable receiving the fork is integral with a base 8 fastened to a rear part of the vehicle 1.
The base 8 may be more particularly seen in
One front branch 9c is fastened to the chassis of the vehicle 1 by a bracket 10 bolted or welded to the chassis through the floor 1a. This bracket moreover has a hinged lashing hook 11 allowing the barrel 3 to be held in place with respect to the vehicle 1 when the vehicle is moving.
The rear branches 9a and 9b are also fastened to the vehicle chassis by means that are not visible in the Figures (for example, bolts).
The rear branches 9a and 9b have arms 12a and 12b which are hinged onto the branches by pins 13 (see
These jacks will be supplied with pressurised fluid by a hydraulic generator 15 fixed to the floor la (see
Locking means 16 are provided on each arm to ensure the immobilization of the arms 12a and 12b in their deployed position. These locking means are shown open in
Each arm 12a, 12b is extended by a spade 17 intended to anchor the arms in the ground and is also fitted with a safety support 18 intended to press on the ground, such support being positioned between the spade 17 and the point of articulation 13 of the arm 12a, 12b in question on its branch 9a, 9b.
Each safety support 18 is rigidly connected to the arm 12a, 12b in question. It may, for example, be fastened to the arm by welding. The arms 12a, 12b and branches 9a, 9b of the base as well as the safety supports 18 are made of mechanically welded plate metal.
Each support 18 has a plate 19 at its foot intended to press on the ground. This plate is intended to supply a bearing surface with the ground that is enough to guarantee the stability of the weapon system even on loose ground.
The plate 19 is linked to the support by a joint which gives it at least three degrees of freedom in rotation with respect to the support (ball and socket type joint), this in order to ensure bearing despite any irregularities of the ground. Such a ball and socket joint is well known to the Expert and is commercially available. It is thus unnecessary for it to be described in detail.
When arms 12a and 12b are in their folded position (
When arms 12a and 12b are in their extended position (
Note that in this case the lock 16 is not yet locked.
For the weapon system to be able to fire, it is necessary for the spades 17 to be pushed into the ground. Indeed, in this case the weapon system is in contact with the ground by a bearing polygon of sufficient size which namely prevents the excessive lifting of the vehicle 1 to the rear under the effect of the cannon 3 recoil.
For the spades to be able to be pushed into the ground, the following procedure is adopted.
After the arms 12a, 12b have been extended rearwards of the vehicle until the safety support 18 rests on the ground, the vehicle 1 is made to reverse under its own motorization.
Each support 18 is rigid with respect to the arm 12a, 12b in question so that the recoiling vehicle causes the arms 12a, 12b to pivot on the ends of the supports 18 thanks to the plates 19.
The spades 17 are thus pushed into the ground and the rear axle 21 of the vehicle 1 lifts up slightly off the ground.
At the same time, this pivoting of the arms results in ensuring the locking of locks 16 ensuring in turn the rigidity of the arm 12a, 12b and branch 9a, 9b assembly integral with the base 8.
The schemas shown in
Point H represents the link between a support 18 and an arm 12a, 12b. Point O represents the joint 13 of the arm 12a, 12b in question and its branch 9a, 9b.
Point A represents the end of the spade 17 pushed into the ground.
Point B represents the ball joint connecting the end of the support 18 and the plate 19 in contact with the ground.
A circle schematizes a wheel on the rear axle 21 which, naturally, is integral with the branches 9a, 9b fixed to the vehicle floor.
a shows one of the arms 12a, 12b when it has been extended, support 18 pressing on the ground.
The vehicle 1 is made to reverse (movement in direction R). The device thus takes up the configuration shown in
The end A (spade 17) pushes in the ground and the arm forms an angle α with the horizontal.
Since the rear axle 21 is no longer in contact with the ground, most of the recoil stresses are taken up by the arms 12a, 12b and their supports 18.
Someone skilled in the art will easily determine the arms and supports according to the characteristics of the vehicle.
An arm length OA will be selected in particular which ensures (for a given vehicle mass) a sufficient lever arm at the rear of the vehicle to prevent it from rolling over during firing. According to the characteristics of the weapon, it is possible for the device according to the invention to be supplemented by means also enabling the elevation of the cannon to be reduced during firing.
Means may be provided at the muzzle brake 4 enabling a torque to be exerted during firing that causes the weapon system 2 to pivot around point A in a direction allowing the support 18 to be more strongly pressed on the ground. These means may be constituted quite simply by one or several drill holes 22 (
The muzzle brake may thus be given an asymmetric shape (for example at its vents 23), such shape ensuring the appearance of stresses making the weapon system pivot in the required direction. For example, it is possible to provide the inside of the brake with a surface onto which the gas pressure is exerted which is greater under rather than over a median plane of the muzzle brake.
Such arrangements related to the muzzle brake do not form the subject of the present invention but are more particularly described in application FR-04.10903 dated 14 Oct. 2004 to which reference may be made.
A low value for angle α enables the amplitude of the rear pivoting to be reduced. This amplitude is also reduced by selecting a distance D between the spade 17 and the ground that is fairly reduced when the arm has just been extended. For a weapon system of a calibre of between 90 mm and 105 mm an angle α will preferably be selected of between 10° and 30° and a distance D will be adopted between the spade and the ground (horizontal) which will be of between 0 mm and 200 mm. The full length of the arms is between 1 and 2 m.
The lifting amplitude of the axle 21 also depends on the distance OH between the joint 13 and the safety support 18.
A distance OH will be chosen, for example, that is between 5% and 20% of the full length of the safety support.
It can be seen that, thanks to the invention, it is possible to provide a link to the ground for a weapon system using relatively simple light means and enabling firing from a relatively light vehicle.
The device according to the invention is also very rapidly implemented, since the vehicle 1 itself is used to ensure anchorage to the ground.
On the contrary, to withdraw the weapon system according to the invention, the arms have firstly to be unlocked (by manual action on the prong 16a which, to this end, is fitted with a handgrip—see
The, the vehicle 1 merely has to be driven forwards. Such an operation ensures the contrary pivoting of the arms 12 and enables the spades to be pulled from the ground.
The arms 12a, 12b are then folded to the front of the vehicle by means of their hydraulic jacks.
In practical terms, the deployment of the weapon system is made is less than 30 seconds. The time required to withdraw the system is roughly the same. When the weapon system is in the firing position (
Pivoting in elevation and in traverse is ensured by electric motors 24 and 25. The pivoting amplitude in traverse is of around 100°; the pivoting amplitude in elevation is of between −10° and +70° with respect to a horizontal plane via trunnions 3c.
Electronic means (not shown) allow firing control. These means are classical and comprise: a firing computer incorporating ballistic data, a global positioning system (GPS) supplemented by an inertial unit and means to communicate with a command post. These means are coupled with the electric motors and enable the rapid laying of the cannon so as to ensure the firing required by the command post.
Naturally, the vehicle may carry a stock of ammunition which will be placed in a rack 23 (see
Number | Date | Country | Kind |
---|---|---|---|
04.13966 | Dec 2004 | FR | national |