GB2353088A - Indicating when ammunition in a projector is spent - Google Patents

Abstract

A container 4 loaded with munitions such as target illumination shells is provided with means for indicating when all the munitions have been fired. When the last munition has been fired from the container a member 8 is urged downwards against a part 12 of the launcher and thus moves the container 4 upwardly and releases a sensor switch 14. The member 8 may be urged downwardly after a shear pin 10 is broken by a pyrotechnic element 5 which is ignited by the combustion gases generated on firing the last munition. In another embodiment (figures 3, 4 not shown) a magnet (50) holds an armature (51) against the bias of a spring 11 until the last munition has been fired.

Description

2353088 DEVICE FOR EMULATING AN EMPTY STATE OF A PROJECTOR FOR SHELLS AS

WELL AS A SHELL THEREWITH The present invention relates to a device for simulation (emulation) of an empty state of a projector for shells according to claim 1, as well as a shell according to claim 9.

So-called projectors are used to fire shells, especially target illumination shells.

The projector itself is, as a rule, able to recognise the loaded state by means of a sensor switch, e.g. a reed switch which is located as a rule in the bottom part of the projector, and to pass this state on to the operating unit.

With shells, especially target illumination shells of newer types, which are constructed on the so-called submunition principle, the empty shell case remains in the projector after firing all sub- munitions.

A loaded projector is therefore reported to the operating personnel, although all sub-munitions have already been fired.

In the light of this situation it was therefore the object of the present invention to provide a device with which a signal is generated after firing the last submunition, which makes a completely fired shell recognisable.

This object is met by a device with the features of claim 1, as well as by a shell according to claim 9.

The device according to the invention for simulation (emulation) of an empty state of a projector for shells comprises a lifting device at the projector end of a shell, which is loaded with sub-munitions, wherein, after firing the last sub-munition, the lifting device drives out a part capable of extension from the shell bottom and releases a sensor switch, which generates a signal, from which a control unit recognises that the ammunition of the projector is spent.

A sensor switch, e.g. a reed switch is released again through the lifting of the empty shell, so that it emulates a state which corresponds to that of an unloaded projector, i.e. without a loaded shell.

The design of the lifting device can vary according to the invention.

According to claim 2 the lifting device comprises a pyrotechnic delay element, which according to claim 3 is arranged in a cylindrical hollow space with a movable part, especially a piston, wherein the delay element is ignited on firing the last sub-munition by the hot combustion gases thereof. The combustion gases of the delay element create an excess pressure in the hollow space and the movable part, on whose lower side facing away from the delay element, the extensible part, especially a platform is arranged, moves in the direction of the shell bottom, whereby the extensible part is driven out from the shell in the direction of a spring force, whereby the shell rises from the projector bottom and thus releases the sensor switch.

The lifting device is preferably fixed in position according to claim 4 by means of a shear pin, so that inadvertent extension of the extensible part is ruled out.

After igniting the pyrotechnic delay element the shear pin is sheared and the piston can move out of the shell bottom with the extensible part and so bear on the projector bottom that the shell is lifted far enough for the sensor switch to be released.

Alternatively, instead of the pyrotechnic delay element an electrical ignition means can be used according to claim 4, which is initiated electrically on firing the last sub munition body. This ignition element includes a gas-forming pyrotechnic charge or causes such to react, which then takes care of the necessary excess pressure in the interior of the hollow space.

An alternative embodiment of the lifting device is claimed in claim 6, with a magnet which can be electrically weakened, especially a holding magnet.

According to claim 7, the magnet retains an armature against the force of a spring, the armature being coupled to the extensible part.

On electrical weakening of the magnet this loses its holding force on the armature and the extensible part is driven out by means of the force of the spring and the shell is thus lifted up enough for the sensor switch to be released and the empty state of the projector is thus emulated.

According to claim 8 it is particularly preferred that a reed switch is used as the sensor switch, since reed switches have proved themselves in practice, are available on the market in many variants and are cheap.

The subject matter of claim 9 is a shell which comprises a device according to the invention for emulation of an empty state of a projector.

Further advantages and features appear from the following detailed description of preferred embodiments which are described by way of example, with reference to the drawings, in which:

Fig. 1 shows a partial longitudinal section through a shell according to the invention with a lifting device according to the invention, wherein the lifting device comprises a pyrotechnic delay element and a projector is in a loaded state; Fig. 2 also shows a partial longitudinal section through a shell according to the invention, wherein the device according to the invention is in a state after igniting the delay element; Fig. 3 is a partial longitudinal section through a shell according to the invention with a magnet which can be weakened electrically, in the loaded state; and Fig. 4 is a partial longitudinal section through a shell according to the invention in the empty state.

A shell according to the invention the invention is denoted 1 in Fig. 1. The shell 1 comprises a lifting device 3 at its projector end 2, which is surrounded by the peripheral wall 4 of the shell 1.

Sub-munitions, not shown in the drawing, of the shell 1 are present above the lifting device 3.

According to Fig. 1, the lifting device 3 comprises a pyrotechnic delay element 5. The delay element 5 is ignited by the hot combustion gases which arise on firing the last sub-munition. The delay element 5 ends on the firing side in a cylinder 6 with a piston 7 as a movable part.

In the example the piston 7 passes directly into a platform 8 as an extensible part, which finishes flush with the shell bottom 9. When the delay element burns through, it creates an excess pressure in the cylindrical hollow space 6 and the piston 7 moves away f rom the delay element 5. in the example a shear pin 10, which keeps the whole lifting device stable before igniting the pyrotechnic delay element, is parted. The platform 8 now moves, assisted by the spring 11, into an outer end position and stays there. The platform 8 bears on the projector bottom, in particular the projector spool 12. The result of this is that the empty shell 1, including the peripheral wall 4, is lifted up in the projector. The ignition coil 13 of the empty fired shell 1 releases a reed switch 14 which acts as the sensor switch of the projector. The release message is communicated to the operating unit of the projector system and thus emulates the empty state of the projector, although the empty shell casing is still present in the projector.

The emulated empty state of the projector is shown in Fig. 2, which is given the same reference numerals as Fig.

1.

An alternative embodiment of the lifting device 3 of the device according to the invention is shown in Figs. 3 and 4. The same parts are given the same reference numerals as Figs. 1 and 2.

Fig. 3 shows the loaded state of the projector while Fig. 4 shows the emulated empty state of a projector.

In the embodiment according to Figs. 3 and 4 the lifting device 3 comprises a holding magnet 50 which can be weakened electrically and which holds an armature 51 fast against the spring force of a spring 11. The armature 51 passes directly into the platform 8, which ends flush with the shell bottom 9. In the state according to Fig. 3 the reed switch 14 as sensor switch of the projector is engaged and communicates the "loaded" state. If now the magnet force of the holding magnet 50 is weakened by application of a voltage pulse, the armature 51 is released and moves, assisted by the spring 11, away from the magnet 50 into the outer end position and stays there. The platform 8 thereby bears on the projector bottom or the projector spool 12. The result of this is that the shell, including the peripheral wall 4, is lifted up.

The ignition coil 13 of the empty fired shell 1 thereby releases the reed switch 14 of the projector. The released message is passed to the operating unit of the projector system By manually pressing the shell or the peripheral wall 4 down into the projector, the platform is pressed in against the spring force, until the armature 51 is again held by the magnet 50. The reed switch 14 is again engaged, the projector communicates the "loaded" state again and the release operation described above can begin afresh.

The particular advantage of the embodiment of the present invention according to Figs. 3 and 4 is based on the fact that it concerns a reversible system, whereby a lifting device 3 is suitable especially for training and test purposes with test shells, through use of a magnet 50 which can be weakened.

6 List of references 1: shell 2: projector end of shell 3: lifting device 4: peripheral wall of the shell 5: pyrotechnic delay element 6: cylindrical hollow space 7: piston 8: platform 9: shell bottom 10: shear pin 11: spring 12: projector bottom/projector spool 13: projector ignition coil 14: reed switch 50: magnet 51: armature

Claims (9)

1. I A device for simulation (emulation) of an empty state of a projector for shells (1); the device comprising a lifting device (3) at the projector end (2) of a shell (1) which is loaded with sub-munitions, wherein, after firing the last sub-munition, the lifting device (3)is operable to drive out a part (8) capable of extension from the shell bottom (9) so as to release a sensor switch (14), which generates a signal, from which a control unit can recognise that the ammunition of the projector is spent.
2. 2. A device according to claim 1, characterized in that the lifting device (3) comprises a pyrotechnic delay element (5).
3. 3. A device according to claim 2, characterized in that is the delay element (5) is arranged in a cylindrical hollow space (6) with a movable part (7), especially a piston (7); and the delay element (5) is ignitable, in use, on firing the last sub-munition by the hot combustion gases thereof, so that the combustion gases of the delay element (5) create an excess pressure in the hollow space (6) and the movable part (7), on whose side remote from the delay element (5)is arranged the extensible part (8), especially a platform (8) is arranged, to drive the extensible part (8) out from the shell (1) in the direction of a spring force, whereby the shell (1) rises from the projector bottom (12) and releases the sensor switch (14).
4. 4. A device according to claim 1, characterized in that the lifting device (3) comprises an electrical ignition element, which causes a reaction of a gas charge, in order to cause the lifting device (3) to operate through the appropriate excess pressure.
5. 5. A device according to any of claims 1 to 4, characterized in that the lifting device (3) is fixed in position by means of a shear pin (10).
6. 6. A device according to claim 1, characterized in that the lifting device (3) comprises a magnet (50), in particular a holding magnet, which can be electrically weakened.
7. 7. A device according to claim 6, characterized in that the magnet (50) retains an armature (51) against the force of a spring (11), the armature being coupled to the extensible part (8).
8. 8. A device according to any of claims 1 to 7, characterized in that the sensor switch (14) is a reed switch.
9. 9. A shell with a device according to at least one of claims 1 to 8.