Abstract:
An ammunition management system for firing mixed ammunition in an automatic cannon. The ammunition management system includes a rotatable ammunition magazine including ammunition shot, a breech casing and an ammunition feed device for feeding of ammunition shot between the ammunition magazine and the breech casing. A drive device drives the ammunition magazine via a chain drive mechanism disposed in the ammunition magazine. A decoupling device engages and disengages the ammunition magazine with respect to the ammunition feed device, so that ammunition can be moved between different positions in the ammunition magazine, via an alternating process including: feeding of ammunition from the ammunition magazine to the ammunition feed device, disengagement of the ammunition magazine, rotation of the ammunition magazine, engagement of the ammunition magazine, and feedback of ammunition from the ammunition feed device to the ammunition magazine. A method for sorting ammunition in a ammunition magazine.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The application claims priority to Swedish patent application 1300692-9 filed 7 Nov. 2013 is the national phase under 35 U.S.C. §371 of PCT/SE2014/000130 filed 3 Nov. 2014. 
     FIELD OF THE INVENTION 
     The present invention relates to an ammunition management system and to a method for sorting and firing mixed ammunition types in an automatic cannon. Included ammunition types can differ in number and type. 
     For present-day ammunition management systems there is a requirement for sorting and firing of mixed ammunition types to proceed quickly, especially in the firing of shots in which shots which are fired in periods following preceding shots are expected to hit the target substantially simultaneously with the previously fired shot or shots. 
     BACKGROUND OF THE INVENTION 
     Ammunition management systems of the kind stated in the introduction, for firing mixed ammunition types in an automatic cannon, are previously commonly known. Examples of such ammunition management systems are described in documents: WO 2009/049710 A1, WO 2009/049721 A1 and WO 2004025209 A1. In the stated documents, devices and methods based on sensor-based functions for feeding different types of ammunition shot (M1, M2, M3) from a plurality of different magazines via a plurality of different chains (Z1-Z3) to an automatic cannon via a common rotor 2 are described, see, for example WO 2009/049721 A1, FIG. 2, abstract and description on page 4. 
     A problem with the said ammunition management systems is the use of a plurality of ammunition magazines and a plurality of feed chains, which makes the systems complex and increases the risk of malfunction, thereby resulting in fire stoppages. 
     The object of the present is to solve, inter alia, these problems. 
     SUMMARY OF THE INVENTION 
     A principal object of the present invention has been to provide a simple and safe ammunition management system for firing mixed ammunition types in an automatic cannon, having few moving parts, high ammunition transfer speed and high reliability, in which the risk of fire stoppages is low. 
     This object, as well as other objectives not enumerated here, is satisfactorily met within the scope of that which is described herein. 
     Thus, according to the present invention, a simple and safe ammunition management system for firing mixed ammunition types in an automatic cannon, having few moving parts and comprising a rotatable ammunition magazine and an ammunition feed device, has been provided. 
     What can principally be considered characteristic is that the ammunition management system comprises a drive device for driving the ammunition magazine via a chain drive mechanism disposed in the ammunition magazine, and that the ammunition management system comprises a decoupling device for engagement and disengagement of the ammunition magazine with respect to the ammunition feed device, so that ammunition can be moved between different positions in the ammunition magazine, via an alternating process comprising: feeding of ammunition from the ammunition magazine to the ammunition feed device, disengagement of the ammunition magazine, rotation of the ammunition magazine, engagement of the ammunition magazine, and feedback of ammunition from the ammunition feed device to the ammunition magazine. 
     According to further aspects of the automatic ammunition management system according to the invention: 
     the ammunition magazine is rotatably disposed on the bottom side of the breech casing in the vertical direction via two front rotation shafts and two rear bolts, and via two handles, one on either side of the ammunition magazine, with which the ammunition magazine can easily be lowered from a tilted-up position into a tilted-down position during servicing or during emptying of the magazine, 
     the ammunition magazine is driven via at least two separate chains, which are synchronized with one another via a system of drive shafts and chain wheels, which distribute the drive force between the chains and ensure that the chains are always synchronized with one another, 
     the chains are manually adjustable via a chain-adjusting mechanism, comprising adjusting screws connected to raisable and lowerable chain holders on the end walls, arranged such that, when a chain holder is adjusted upwards in the height direction, pretension in the chain increases and, when a chain holder is adjusted downwards in the height direction, the pretension decreases, 
     the ammunition magazine comprises a hatch for manual feed-in and feed-out of ammunition to the ammunition magazine, 
     the ammunition magazine comprises an external angle encoder, configured to verify the position of the ammunition in the ammunition magazine, wherein the angle encoder is mounted on one of the drive shafts of the ammunition magazine via a flexible damping device in order to minimize the effect of harmful shocks or vibrations, 
     the ammunition magazine is connected to the ammunition feed device via a coupling shaft configured with square cross section, which makes it impossible to connect the magazine to the ammunition feed device incorrectly. 
     According to the present invention, a method for sorting mixed ammunition types in an ammunition management system, comprising a rotatable ammunition magazine, an ammunition feed device, a breech casing and a decoupling device for decoupling the ammunition feed device from the ammunition magazine, has also been provided. 
     What can principally be considered characteristic of the method is that the method comprises the following stages: feeding of ammunition from the ammunition magazine to the ammunition feed device; decoupling of the ammunition magazine from the ammunition feed device via the decoupling device; rotation of the ammunition magazine into a new position; coupling of the ammunition magazine with the ammunition feed device, and feeding of ammunition from the ammunition feed device into the new position in the ammunition magazine, whereafter the said stages are repeated until the ammunition is ready-sorted. 
     As a result of that which has been proposed above, an advantageous ammunition management system which means a simplified ammunition sorting of mixed ammunition types in an automatic cannon is obtained. 
     The invention means that the ammunition management system can choose between several different sorting programs. The software of the gun keeps track of different ammunition types and their placement in the ammunition magazine. No manual sorting is required. The invention solves the drawbacks which arise where a plurality of ammunition magazines are used in the sorting of different ammunition types. The use of just one ammunition magazine offers the advantages, above all, of a more lightweight product which is simpler, faster and has greater reliability. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A currently proposed embodiment of an ammunition management system which has the characteristics significative of the invention is described below with simultaneous reference to the appended drawings, in which: 
         FIG. 1  shows an ammunition management system according to invention, mounted in an automatic cannon, 
         FIG. 2  shows the ammunition magazine according to  FIG. 1 , viewed obliquely from the rear, 
         FIG. 3  shows an enlargement of the ammunition-adjusting mechanism according to  FIG. 2 , 
         FIG. 4  shows the relative positions of the star wheels and pawls, disposed in the ammunition management system, in the chain feed mechanism when ammunition is fed from the magazine to the breech casing of the cannon, 
         FIG. 5  shows the relative positions of the star wheels and pawls, disposed in the ammunition management system, in the chain feed mechanism when ammunition is fed from the breech casing of the cannon to the magazine, 
         FIG. 6 a    shows an ammunition feed device, disposed in the ammunition management system, for manual feed-in and feed-out of ammunition to and from the magazine, wherein the said ammunition is shown in fed-in position in the magazine, 
         FIG. 6 b    shows the ammunition feed device according to  FIG. 6 a   , wherein the ammunition is shown in fed-out position in the magazine, 
         FIG. 7  shows a drive device, disposed in the ammunition management system, for driving the magazine, 
         FIG. 8  shows an external angle encoder for monitoring the placement of the ammunition in the magazine, 
         FIG. 9  shows a decoupling mechanism, disposed in the ammunition management system, for decoupling the magazine from the ammunition feed device in the resorting of ammunition, wherein the decoupling mechanism is shown in the deactivated state, 
         FIG. 10  shows the decoupling mechanism according to  FIG. 9  in the activated state. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows an ammunition management system  1  according to the invention, disposed in an automatic cannon  2 . The ammunition management system comprises an ammunition feed mechanism  3 , also referred to as an ammunition feed device, and a rotatable ammunition magazine  4  comprising ammunition  5 , also referred to as ammunition shot or ammunition unit, wherein the ammunition magazine  4  and ammunition feed mechanism  3  are driven by a common drive device  6 . 
     The ammunition magazine  4  is rotatably and detachably arranged directly on the breech casing  7  of the automatic cannon  2 , below the ammunition feed mechanism  3 , via two front rotation shafts  8  and two rear bolts  9 . In the rotatable ammunition magazine  4  there is arranged 10-50 ammunition shots  5 , preferably 15 ammunition shots  5 , ready to be fired from the automatic cannon  2 . When the automatic cannon  2  is ready to fire, ammunition units  5  are fed from the ammunition magazine  4  to the breech casing  7  via the ammunition feed device  3 . 
     The drive device  6  comprises an electric motor  10  for driving the ammunition magazine  4  and the ammunition feed mechanism  3  via a chain drive mechanism  11  disposed in the front and rear end walls  12 ,  13  of the ammunition magazine  4 ,  FIG. 2 . 
     The ammunition management system  1  is arranged such that, when the ammunition magazine  4  rotates anti-clockwise (viewed from the rear from the rear end wall  13 ), ammunition is fed from the ammunition magazine  4  to the breech casing  7  of the cannon. Clockwise rotation of the ammunition magazine  4  is used for emptying of ammunition  5  and in the sorting of mixed ammunition  5  in the ammunition magazine  4 . Adjacent to the chain drive mechanism  11  and the ammunition feed mechanism  3  there is arranged a disengaging device  14 , configured as a claw coupling, which makes it possible to rotate the ammunition magazine  4  even when the ammunition feed device  3  is stationary. By alternating between anti-clockwise and clockwise rotation of the ammunition magazine  4 , corresponding to feed-in/feed-out of ammunition  5  to/from the ammunition feed device  3 , it is possible to sort the ammunition  5  in the ammunition magazine  4  according to a preselected sorting program. 
     The ammunition management system  1  comprises, apart from the ammunition magazine  4 , the feed mechanism  3 , the chain drive mechanism  11  and the disengaging device  14 , as well as an angle encoder  15  for registering the relative position of the ammunition  5  in the ammunition magazine  4 . 
     The ammunition magazine  4  is accessible in a simple and manageable manner, for example in connection with servicing or when the ammunition magazine  4  needs to be emptied quickly, via two rear, releasable bolts  9  and two handles  15 , one on either side of the ammunition magazine  4 , with which the ammunition magazine  4  can be lowered from a tilted-up position into a tilted-down position. 
     On the top side of the ammunition magazine  4  there is arranged a protruding locking shaft coupled to a cardan joint, which has to be released before the ammunition magazine  4  can be lowered. 
     The ammunition magazine  4  with ammunition  5 , chain drive mechanism  11  and end walls  12 ,  13  is held together by two beams  17 , mounted between the end walls  12 ,  13 , and a centre bracket  27  fitted to the beams  17 . End walls  12 ,  13  and the beams  17  are preferably made of aluminium or steel. 
     The ammunition magazine  4  is driven by the chain drive mechanism  11  via two separate chains  18  disposed in the front end wall  12  and in the rear end wall  13  respectively. The chains  18  are synchronized with one another via a number of drive shafts  19 , which distribute the drive force from the electric motor  10  to the chains  18 . In total, six drive shafts  19  and six chain wheels  20  are used, which ensures that the chains  18  are always synchronized with one another, even if one of the chains  18  is loose. There is also the possibility of adjusting the chains  18  manually via a chain-adjusting mechanism  21 . The adjustment is made with the aid of adjusting screws  22  connected to raisable and lowerable chain holders  23  on the end walls  12 ,  13 . When a chain holder  23  is adjusted upwards in the height direction, pretension in the chain  18  increases, and when a chain holder  23  is adjusted downwards in the height direction, the pretension decreases,  FIG. 3 . The degree of pretension is monitored via graduated scales  24 , arranged adjacent to a chain holder  23 . 
     The ammunition  5  is transported around in the ammunition magazine  4  via/on guide rods  25 , which are coupled to the chain drive mechanism  11  via mounting pins  26 . 
     The star wheels  28 ,  FIG. 4 , are mechanically synchronized with the chains  18  and will always correspond with the space (distance) between the ammunition  5 . The primary task of the star wheels  28  is to feed ammunition  7  to and from the ammunition feed device  3  via spring-loaded pawls  29 ,  FIG. 4  and  FIG. 5  respectively. When the ammunition  5  is fed to the breech casing  7  of the cannon, the chains  18  rotate clockwise. The star wheels  28  press the ammunition  5  against the spring-loaded pawls  29 , which guide ammunition  5  out from the ammunition magazine  4  and onwards into the ammunition feed device  3 ,  FIG. 4 . 
     When the ammunition  5  moves in the opposite direction, anti-clockwise, in the ammunition magazine  4 , the spring-loaded pawls  29  will be opened when the ammunition  5  presses on the pawls  29 , while the ammunition  5 , if there is any ammunition  5  in the feed-in position of the ammunition feed device  3 , can be fed back to a vacant position in the ammunition magazine  4  unless the decoupling device  14  is activated and prevents disengagement,  FIG. 10 . 
     In the upper right-hand corner of the rear end wall  13  there is a hatch  30  intended for manual loading/unloading of ammunition  5  to/from the ammunition magazine  4 . In the case of loading, ammunition  5  is introduced into the ammunition magazine  4  via the hatch  30  into a position in which the flange  31  of the ammunition casing meets a stop in the end wall  13 , whereafter the ammunition unit  5  is pressed down into its intended position with the aid of a spring-loaded hook  32 . By pulling on a black handle  33  on the end wall  13 , a spring-loaded ejection mechanism  34  is activated, which ejects the ammunition  5 ,  FIGS. 6 a    and  6   b.    
     The ammunition magazine  4  and the ammunition feed device  3  are driven by a drive unit comprising a planetary gear, a servomotor  10  having a built-in absolute angle encoder (internal angle encoder), and a mechanical brake. 
     The internal encoder in the servomotor  10  is used to monitor the ammunition magazine  4 . If a power cut occurs, the mechanical brake will be activated, whereupon the ammunition magazine  4  comes to a halt and is locked. It is nevertheless still possible to release the brake on condition that the power system is engaged, the magazine  4  being manually rotatable with the aid of a hand-operated crankshaft. 
     The drive device  6  comprises an electric motor  10  for driving the ammunition magazine  4  and the ammunition feed mechanism  3  via a chain drive mechanism  11  disposed in the front and rear end walls  12 ,  13  of the ammunition magazine  4 . The chain mechanism  11  is driven via a front drive shaft  37  on the front end wall  12 . To the front drive shaft  37  is also fitted a planetary gear  35 , to which the drive shaft of the electric motor  10  is connected via a fixed hub  36 . The hub  36  is mounted with a hexagon socket head screw, which is accessible via the mounting plate. The motor  10  has two connections, an X 1  connection for mains supply and an X 2  connection for signal. 
     An external angle encoder  38  is positioned on the front end wall  12  of the ammunition magazine  4 , in which it is mounted on one of the drive shafts via a flexible damping device in order to minimize the effect of harmful shocks or vibrations. The external encoder  38  is used only to verify that position of the ammunition  5  which is given by the internal encoder in the servomotor  10 . 
     In loading and unloading of ammunition  5  to the ammunition feed mechanism  3  from the ammunition magazine  4 , the movement of the ammunition magazine  4  is synchronized with the star wheel  28  in the chain drive mechanism  11  via three gearwheels in the decoupling device  14 . In the stated case, the decoupling device  14  is always deactivated. 
     In order to enable reorganization and shifting of ammunition  5  between different ammunition types  5  in the ammunition magazine  4 , the ammunition feed device  3  must be able to be decoupled from the ammunition magazine  4 , i.e. the decoupling device  14  must be activated, which is done with the aid of a solenoid, which controls the decoupling device  14 . 
     The decoupling device  14  comprises a rear movable claw, which is activated once the solenoid has pressed back the claw into its rear position. In the event of a power cut, the decoupling device  14  will remain deactivated due to pre-loaded helical springs which act on the disengaging device  14  such that the movable claw of the decoupling device  14  is kept pressed back in its rear position. An inductive sensor  39 ,  FIG. 9 , directed towards the flange of the movable claw, signals when the claw changes position, i.e. when the decoupling device  14  is activated. 
     The ammunition magazine  4  is connected to the ammunition feed device  3  via a coupling shaft  40 ,  FIG. 9 , configured with square cross section, which makes it impossible to connect the magazine  4  to the ammunition feed device  3  incorrectly. In order to remove or lower the ammunition magazine  4 , the ammunition magazine  4  must be decoupled from the ammunition feed device  3 . The decoupling can be realized by connecting an M8-screw to the coupling shaft  40  and subsequently pulling on the coupling shaft  40  such that it comes loose from the cardan joint in the ammunition feed device  3 .