Patent Publication Number: US-6339983-B1

Title: Ammunition-feeding device for a cannon

Description:
FIELD OF THE INVENTION 
     The invention relates to an ammunition-feeding device for a cannon, wherein the ammunition-feeding device has mechanisms for the conveyance and transfer of cartridges to the cannon. 
     BACKGROUND OF THE INVENTION 
     An ammunition-feeding device has become known from Swiss Pat. Application 01 587/95-6, which has a conveyor chain rotating in a housing of a magazine. Cups are provided on the conveyor chain, in which cartridges are held during the transport to a drum of a revolver cannon. Star-shaped reversing wheels and star-shaped transfer wheels, which are seated on a common rotatable shaft, are located at a reversing position of the conveyor chain facing the drum, wherein the reversing wheels are in engagement with the conveyor chain. A first conveyor link provided in the area of the reversing wheels takes over cartridges from the conveyor chain, or respectively the transfer wheels, wherein the cartridges are transported along a guide surface in the shape of an arc of a circle away from the transfer wheels to a second conveying link. The first conveying link consists of two trifurcate stars arranged on a common rotatable shaft, whose gaps are matched to the cross-sectional shape of the cartridges. The second conveyor link is also arranged to be rotatable and has a guide surface for guiding respectively one cartridge. A loading star is fastened on the drum and extends coaxially with it, to which the second conveying link transfers the cartridges. A scanning device arranged above a cartridge on the second conveying link, for example in the form of a photoelectric barrier, checks the position of the first cartridge. If a cartridge is present, a loading device is activated and the cartridges are pushed into the drum. 
     It is not possible to achieve faster rates of fire by means of the above described ammunition-feeding device. Moreover, the energy expenditure for conveying the cartridges is relatively great. 
     OBJECT AND SUMMARY OF THE INVENTION 
     It is the object of the invention to propose an ammunition-feeding device of the type mentioned at the outset, which does not have the above mentioned disadvantages. 
     This object is attained by means of an axial transport device with a conveyor chain, by means of which the cartridges are displaced during the transport in their longitudinal direction vertically in respect to the movement direction of the conveyor chain. A buffer shaft is provided for driving the conveyor chain, wherein the drive of the conveyor chain by means of the buffer shaft is performed in such a way that the cartridges are placed into a buffer position prior to being transferred to the cannon. 
     The advantages obtained by means of the invention are seen to be in particular in the buffering capability of the axial transport device, by means of which a more rapid rate of fire is made possible, and driving energy can be saved. Above all, the proposed axial transport device allows the seating of the cannon in the center of gravity, by means of which the dynamic behavior and the energy requirements of the elevation movement of the cannon are improved. Further advantages are to be seen in the modular construction of the ammunition-feeding device in accordance with the invention, so that production and maintenance costs can be lowered. 
     The invention will be explained in greater detail in what follows by means of several exemplary embodiments, making reference to the drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic representation of the ammunition-feeding device in accordance with the invention, 
     FIG. 2 is a view from above on the axial transport device of the ammunition-feeding device of FIG. 1 in a simplified representation, 
     FIG. 3 shows axial guidance devices for the axial transport device in an enlarged scale, 
     FIG. 4 shows a portion of a conveyor chain of the axial transport device, 
     FIG. 5 shows a carrier tube of the conveyor chain in FIG. 4, 
     FIG. 6 shows a buffer shaft of the axial transport device, 
     FIG. 7 represents a cross sectional view of the buffer shaft along the line VII—VII in FIG. 6, 
     FIG. 8 is a longitudinal section of the buffer shaft in a second embodiment, 
     FIG. 9 is a first schematic representation of the functioning of the buffer shaft in FIGS. 6 and 8, 
     FIG. 10 is a second schematic representation of the functioning of the buffer shaft in FIGS. 6 and 8, and 
     FIG. 11 is a distance/time diagram of the conveyor chain of the axial transport device. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In FIG. 1, a magazine is identified by  1 , which has a conveyor chain  3 , formed of cup-like holding links for cartridges  2 , which is guided over chain reversing wheels  4  and which can be supplied with cartridges  2  via a loading opening  5 . The magazine  1  is in connection with a conveyor  6 , which also has a conveyor chain  9  formed of cup-like holding links for the cartridges  2  and is guided over chain reversing wheels  7 ,  8 . By means of play between the holding links, the conveying chain  9  is able to store a few cartridges, so that it is possible to compensate special operating conditions or malfunctions. The cartridges  2  are transferred by means of a transfer wheel  10  from the magazine  1  to the conveyor  6 , wherein the conveyor chains  3  and  9  of the magazine  1 , or respectively of the conveyor  6 , are driven by a motor  11 . The conveyor chains  3  and  9  are guided in guide grooves, not represented, of housings  12  and  13  of the magazine  1 , or of the conveyor  6 . The conveyor  6  is connected with the cradle  16  of a revolver cannon via a flexible zone  14  for elevation compensation and via a conveyor reversing station  15 . 
     The conveyor reversing station  15  consists of a housing  17  with a front transfer wheel  18 , the chain reversing wheel  8  and a cup guidance and cartridge guidance, not represented. The cartridges  2  are transferred to the front transfer wheel  18  in the conveyor reversing station  15 , and the empty conveyor chain  9  is reversed and guided back to the magazine  1 . The front transfer wheel  18  transfers the cartridges  2  to an axial transport device  19 , which will be described in greater detail later by means of FIG.  2 . The conveyor reversing station  15  is connected via a gear with the axial transport device  19 , wherein the gear is constituted of gear wheels arranged on the shafts of the chain reversing wheel  8  and the transfer wheel  18 , as well as of a buffer shaft  35  (FIGS. 6 to  8 ) of the axial transport device  19 . 
     The axial transport device  19  is connected via a further gear with a transfer station  20 , which consists of a housing  21 , a rear transfer wheel  22 , a reversing wheel  23 , a further transfer wheel  24 , a compensating guide for the weapon recoil and a cartridge guide. The further gear is formed by gear wheels arranged on the shafts of the transfer wheels  22 ,  24  and the reversing wheel  23 , as well as on the buffer shaft  35  of the axial transport device  19 . The transfer station  20  takes over the cartridges  2  from the axial transport device  19  by means of the rear transfer wheel  22  and delivers them via the reversing wheel  23  and the further transfer wheel  24  to a revolver drum  25  of the revolver cannon. The revolver drum  25  has four cartridge layers, for example, the lowest of which is respectively located in the firing axis  26 . The compensating guide compensates the recoil of the weapon in a manner not further represented and guides the cartridges  2  into the cartridge guide. The upper end of the compensating guide is rotatably seated on the housing  21 , which also follows the recoil of the weapon, while the lower end of the compensating guide is fastened on the axial transport device  19 . 
     In accordance with FIGS. 2 to  8 , the axial transport device  19  consists of a housing  30 , composed of two plates  31 . 1  and  31 . 2 , a casing  32  and a guide plate  33 , a conveyor chain  34 , a buffer shaft  35 , chain reversing wheels  36 ,  36 ′ and two chain reversing wheels  37 , wherein the chain reversing wheels  36 ,  36 ′ are connected with each other by the buffer shaft  35 , while the chain reversing wheels  37  are seated independently of each other at the plates  31 . 1 , or respectively  31 . 2 . Guide grooves  38  (FIG. 3) for the conveyor chain  34  are provided in the plates  31 . 1 ,  31 . 2 . The casing  32  prevents cartridges  2  from falling out, and on the interior it has two axial guides  39 ,  40  (FIGS. 2,  3 ), which extend at a slant angle in relation to the conveyor chain  34  and by means of which the cartridges  2  are displaced in their longitudinal direction during transport vertically in respect to the movement direction of the conveyor chain  34 . Starting at the entry of the cartridges  2  at the front transfer wheel  18  of the conveyor reversing station  15 , the axial guides  39 ,  40  first cross the lower stringer and then the upper stringer of the conveyor chain  34  and end at the exit of the cartridges  2  at the rear transfer wheel  22  of the transfer station  20 . During movement of the conveyor chain  34  in the direction toward the revolver drum  25 , the one axial guide  39  leads the cartridges  2  at the shell mouth  2 . 1 , while the other axial guide  40  controls the position of the cartridges  2  and, in the course of the movement of the conveyor chain  34  in the direction toward the conveyor  6 , leads them at the shell bottom  2 . 2  (FIG.  3 ). The guide plate  33  is fastened on the plates  31 . 1 ,  31 . 2 . In this way it spaces the two plates  31 . 1 ,  31 . 2  apart and guides, or respectively separates, the cartridges  2  in the two stringers of the conveyor chain  34  from each other. 
     In accordance with FIGS. 4,  5 ,  9  and  10 , the conveyor chain  34  consists of two roller chains  50 ,  50 ′ between which carrier tubes  51  are arranged. End pieces  52 , which have receiving bores  53 , are provided at the ends of the carrier tubes  51 . Carrier pins  54  of the roller chains  50 ,  50 ′ engage the receiving bores  53  with play, wherein the play is of such a size that an inclined position of the carrier tubes  51  of +/−2 degrees is possible. 
     In accordance with FIGS. 6 and 7, the buffer shaft  35  consists of two parts, which are connected with each other by means of a claw coupling  60 . Bolts  61  are provided on the one coupling part  60 . 1 , which engage slits  62  in the shape of an arc of a circle in the other coupling part  60 . 2 . The arc length of the slits is of such a size that the coupling parts  60 . 1 ,  60 . 2  can be turned in respect to each other by a cartridge spacing Pt, or respectively the distance of the carrier tubes  51  of the conveyor chain  34  from each other. Gear wheels  63 ,  63 ′ and the chain reversing wheels  36 ,  36 ′ are fastened on the ends of the buffer shaft  35 . 
     It is also possible to design the claw coupling with resilient detents instead of the fixed detents provided by the slits  62 , as in FIGS. 6 and 7. 
     It is furthermore possible to design the buffer shaft  35  as a torsion shaft, wherein the turning up to a maximum torque corresponds to +/− one-half cartridge spacing P/t 2. 
     The buffer shaft  35  in accordance with FIG. 8 has a torsion shaft  65  and a detent tube  66  extending coaxially to it. The gear wheels  63 ,  63 ′ and the chain reversing wheel  36 ,  36 ′ are fastened at the ends of the torsion shaft  65 . On its end, the detent tube  66  has two cutouts  67 , which are engaged by detents  68  fastened on the one chain reversing wheel  36 . The other end of the detent tube  66  is firmly connected with the other chain reversing wheel  36 ′. The arc length of the cutouts  67  is of such a size, that the torsion shaft  65  can be turned by one cartridge spacing Pt, or respectively by the distance between the carrier tubes  51  of the conveyor chain  34  from each other. 
     Time is associated with the abscissa and the angle of rotation W of the revolver drum  25  with the ordinate in FIG. 11. A distance/time characteristic curve of the one roller chain  50  is identified by K 1 , and a distance/time characteristic curve of the other roller chain  50 ′ is identified by K 2 . The coordinates R 1  to R 5  identify the instants of shots which are fired during a defined length of time during one rotation of the revolver drum  25 . An occurring distance difference D between the two roller chains  50 ,  50 ′ is compensated by means of the buffer effect of the axial transport device  19  achieved by the buffer shaft  35  and, if required, by the play in the conveyor chain  9  of the conveyor  6 . Stops of the conveyor  6  and of the revolver cannon are identified by St-F and St-K. 
     The above described axial transport device  19  operates as follows: 
     Prior to firing, the one roller chain  50  of the axial transport device  19  is driven by the drive of the conveyor reversing station  15  via the gear wheel connected with the front reversing wheel  18  and the gear wheel  63  of the buffer shaft  35 , as well as via the chain reversing wheel  36 , wherein the one part of the buffer shaft  35  is turned by half a cartridge length Pt/2 until it arrives at a detent (FIG.  9 ). 
     During this action, the gear of the transfer station  20  blocks the other roller chain  50 ′ via the gear  63 ′ and the other part of the buffer shaft  35  with the chain reversing wheel  36 ′, so that the carrier tubes  51  of the conveyor chain  34  and the cartridges  2  are inclined by an angle of approximately 2 degrees out of the center position and take up a buffer position (FIG.  9 ). During firing, the canon can pull out one cartridge  2  without the roller chain  50  needing to move. Because of the explosive pressure generated during firing, the revolver drum  25  turns, so that the other roller chain  50 ′ is very rapidly driven by the transfer station  20  and the gear wheel  63 ′ as well as the chain reversing wheel  36 ′ and the carrier tubes  51 , as well as the cartridges  2  are inclined by an angle of approximately 2 degrees in the other direction (FIG.  10 ). 
     During firing, the roller chains  50 ,  50 ′ of the conveyor chain  34  move simultaneously in accordance with the distance/time characteristic lines K 1 , or respectively K 2 , in FIG.  11 . The revolver drum  25  of the cannon drives the roller chain  50 ′ in steps, which moves quickly in the process and is stopped again, namely twice per shot (R 1  to T 5 , K 2 , FIG.  11 ). The other roller chain  50  driven by the conveyor reversing station  15  runs continuously and follows the middle cadence of the cannon (K 1 , FIG.  11 ). In the process, drive energy is saved by making use of the buffering ability of the axial transport device  19 , provided by means of the buffer shaft  35 , and possibly because of the play in the conveyor chain  9  of the conveyor  6 . 
     If a torsion shaft is used as a buffer shaft, the torsion shaft is pre-stressed out of its center position by half a cartridge spacing Pt/2 by the conveyor  6  prior to firing. During firing, the cannon relieves this stress when pulling off a cartridge  2  and then pre-stresses the torsion shaft in the opposite direction.