AUTOMATED PROGRESSIVE AMMUNITION, IN PARTICULAR CARTRIDGE, ASSEMBLY APPARATUS AND METHOD WITH FEEDBACK ASSEMBLY CONTROL

Abstract

The invention relates to an automated progressive ammunition, in particular cartridge, assembly apparatus (1) and method. The automated progressive ammunition assembly apparatus (1) according to the invention comprises a conveyor subsystem (4) and at least one assembly station (5). The at least one assembly station (5) comprises an actuator subsystem (8), a measurement subsystem (12) and a control subsystem (13). The conveyor subsystem (4) is adapted to transport the ammunition (2, 3) past the at least one assembly station (5) in an assembly direction (6) preferably along a rectilinear path. The actuator subsystem (8) is adapted to move a component (9), such as a powder or propellant (10) or a projectile (11), thereby adding the component to the ammunition. The component thus changes at least one physical parameter (P) of the ammunition. The measurement subsystem (12) is adapted to measure the at least one physical parameter and output a measurement signal (15), representative of the at least one physical parameter. In order to be able to meet very tight product specifications, and at the same time allow a quick change between the manufacture of different types of ammunition using the same apparatus (1), the subsystem (21) is adapted to control the actuator subsystem (8) depending on the measurement signal. The at least one assembly station (5) may, in particular, be a powder filling station (18) or a projectile insertion station (27) where powder (10) or a projectile (11) is added to the ammunition.

Claims

1. Automated progressive ammunition, in particular cartridge, assembly apparatus (1) comprising a conveyor subsystem (4) and at least one assembly station (5), the at least one assembly station comprising an actuator subsystem (8), a measurement subsystem(12) and a control subsystem (13), the conveyor subsystem (4) being adapted to transport ammunition (2, 3) past the at least one assembly station in an assembly direction (6), the actuator subsystem (8) being adapted to add a component (9) to the ammunition, the component changing at least one physical parameter (P) of the ammunition, the measurement subsystem (12) being adapted to measure the at least one physical parameter and output a measurement signal (15) representative of the at least one measured physical parameter, wherein the control subsystem (13) is adapted to control the actuator subsystem (8) depending on the measurement signal.

2. Automated progressive ammunition assembly apparatus (1) according to claim 1, wherein the control subsystem (13) comprises a storage member (22) in which a representation of at least one target physical parameter (T) is retained and wherein the control subsystem (13) is adapted to control the actuator subsystem (8) depending on a deviation of the at least one measured physical parameter (P) from the at least one target physical parameter.

3. Automated progressive ammunition assembly apparatus (1) according to any one of claim 1 or 2 wherein the conveyer subsystem (4) comprises a conveyer belt (41) comprising compartments (42) configured to receive the ammunition (2,3) and the conveyer belt (41) extends at least sectionwise linearly to transport the ammunition past the at least one assembly station (5).

4. Automated progressive ammunition assembly apparatus (1) according to the previous claim, wherein the conveyer subsystem (4) is assembled as a loop (55) around two pulleys (50), which lie on an axis and are rotated by means of a driver (57).

5. Automated progressive ammunition assembly apparatus (1) according to any one of claims 1 to 4, wherein the at least one assembly station (5) is a powder filling station (18).

6. Automated progressive ammunition assembly apparatus (1) according to any one of claims 1 to 5, wherein the component (9) is a propellant (10) and wherein the at least one physical parameter (P) is powder weight (W) in the cartridge (2, 3).

7. Automated progressive ammunition assembly apparatus (1) according to any one of the previous claims, wherein the measurement subsystem (12) comprises a net weighing apparatus (20a) which is arranged in the assembly direction (6) before the actuator subsystem (8) and a gross weighing apparatus (20b) which is arranged in the assembly direction (6) behind the actuator subsystem (8).

8. Automated progressive ammunition assembly apparatus (1) according to any one of the previous claims, wherein the measurement subsystem (12) comprises a weighing apparatus (20a, 20b) which has a weighing cell (69) that is arranged in line with the conveyor subsystem (4).

9. Automated progressive ammunition assembly apparatus (1) according to the previous claim, wherein the weighing cell (69) is mounted flush to a transport plane (44) an which the ammunition (2, 3) stands while being pushed by the conveyor subsystem (4).

10. Automated progressive ammunition assembly apparatus (1) according to claim 8 or 9, wherein the weighing cell (69) comprises a centering mechanism (71) which is adapted to move automatically the ammunition (2, 3) away from contact with the conveyor subsystem (4) upon transport of the ammunition (2,3) onto the weighing cell (69).

11. Automated progressive ammunition assembly apparatus (1) according to claim 10, wherein the centering apparatus (71) comprises a spring drive (72) with at least one centering bevel (74), the spring drive being adapted to be automatically loaded by the ammunition (2, 3) transported by the conveyor subsystem (4) onto the weighing cell (69).

12. Automated progressive ammunition assembly apparatus (1) according to claim 10 or 11, wherein the centering apparatus (71) comprises a spring drive (72) with at least one centering bevel (74), in which the ammunition (2,3) is held spaced apart from conveyor subsystem (4) during a working cycle of the conveyor subsystem (4).

13. Automated progressive ammunition assembly apparatus (1) according to any one of the previous claims, wherein the measurement subsystem (12) comprises a weighing apparatus (20a, 20b) comprising a weighing cell (69) and the apparatus comprises a transport device (120) adapted to separate the ammunition (2,3) from the conveyor subsystem (4) in order to pass them onto the weighing cell (69).

14. Automated progressive ammunition assembly apparatus (1) according to the previous claim, wherein conveyor subsystem (4) comprises a conveyor belt (41) configured to transport the ammunition (2,3) within compartments (42) and the transport device (120) comprises at least one transport wheel (122, 123) adapted to receive the ammunition (2, 3) from said compartments (42) and transport the ammunition (2,3) onto the weighing cell.

15. Automated progressive ammunition assembly apparatus (1) according to any one of the previous claims, which apparatus (1) comprises a projectile insertion station (27), the component (9) is a projectile (11) and the at least one physical parameter (P) is a length (L) of a cartridge (3) with an inserted projectile (11).

16. Automated progressive ammunition assembly apparatus (1) according to any one of the previous claims, which apparatus (1) comprises a plurality of assembly stations (5), wherein the conveyor subsystem (4) extends linearly at least sectionwise through the automated progressive ammunition assembly apparatus (1) and the assembly stations (5) are arranged rectilinearly one behind the other in the assembly direction (6).

17. Automated progressive ammunition assembly apparatus (1) according to any one of the previous claims, which apparatus (1) further comprises a horizontal bulkhead (66) which separates an upper manufacturing space (67), in which the conveyor subsystem (4) and at least one assembly station (5) are arranged, from a lower bottom space (68) in a dust-tight manner.

18. Automated progressive ammunition assembly system (110) comprising at least two automated progressive ammunition assembly apparatuses (1) according to any one of claims 1 to 17, wherein the conveyor subsystems (4) of the apparatuses are arranged parallel and side-by-side and wherein at least one assembly station (5) of one automated progressive ammunition assembly apparatus (1) shares at least one reservoir (39, 90, 91) with an adjacent automated progressive ammunition assembly apparatus (1).

19. Automated progressive ammunition, in particular cartridge, assembly method comprising the steps of adding a component (9) to the ammunition (2, 3) thereby changing a physical parameter (P) of the ammunition (2,3), of automatically measuring the physical parameter and of automatically modifying the addition of the component depending on the measured physical parameter.

Description

[0090] In the drawings:

[0091] FIG. 1 shows a schematic representation of an automated progressive ammunition assembly apparatus and method according to the invention;

[0092] FIG. 2 shows a schematic perspective view of a preferred embodiment of an automated progressive ammunition assembly apparatus according to the invention;

[0093] FIG. 3 shows a schematic view of a detail of FIG. 2;

[0094] FIGS. 4 to 6 show schematic views of a preferred measurement subsystem for measuring the weight of a cartridge according to the apparatus and method according to the invention;

[0095] FIG. 7 shows a schematic perspective view of a powder filling station according to the invention;

[0096] FIG. 8 shows a schematic perspective view of a system which comprises two apparatus according to the invention;

[0097] FIG. 9 shows a schematic representation of a preferred embodiment of an apparatus according to the invention, wherein the assembly stations and the conveyer system are attached to the mounting plane; and

[0098] FIG. 10 shows a schematic view of a further preferred measurement subsystem for measuring the weight of a cartridge comprising a rotatable transport device

[0099] First, the basic design and function of an automated progressive ammunition assembly apparatus 1, according to the invention, is explained with reference to FIG. 1. In FIG. 1, each step carried out by the apparatus 1 is represented by a block. As each step is carried out by a specific dedicated structure of the apparatus 1, the blocks of FIG. 1 also schematically represent the structural outline of the apparatus 1.

[0100] The apparatus 1 as shown uses shells 2 to produce cartridges 3. To this end the shells 2 are filled with a propellant, i.e. ammunition powder, and a projectile 11. Commonly the end products, i.e. shells 2 comprising the propellant and the projectile 11, are referred to as cartridges 3. However in the context of the invention shells may also be referred to as cartridges, which are not fully assembled. For the sake of simplicity the terms shells and cartridges are therefore preferably used synonymously, except where a clear differentiation seems to be more appropriate.

[0101] In the embodiment shown, the apparatus 1 comprises a conveyor subsystem 4, which is schematically represented by the arrows between the blocks.

[0102] The conveyor subsystem 4 linearly transports shells 2 and cartridges 3 from one assembly station 5 to the next. At each station 5, a single manufacturing and/or control step is performed on the shell 2 or the cartridge 3.

[0103] The conveyor subsystem 4 is adapted to move linearly, i.e. in a straight line from one assembly station 5 to the next. Thus, the assembly stations 5 are lined up linearly in an assembly direction 6, in which the cartridges 3 are transported. The conveyor subsystem 4 is adapted to move intermittently between the stations by switching between a transport cycle, in which the cartridges 3 are moved, and a working cycle, in which the cartridges 3 rest and are being worked upon. The transport and the working cycle are constant throughout the manufacturing process of at least one variant or type of cartridge 3. The assembly stations 5 are spaced apart from each other in the assembly direction 6 in an integer multiple of the step width of the transport cycle.

[0104] Each assembly station 5 may comprise several subsystems. One such subsystem may be an actuator subsystem 8, which performs a particular assembly step e.g. by adding a component 9, such as a propellant or powder 10 or a projectile 11, to a cartridge 3.

[0105] The assembly station 5 may further be provided with a measurement subsystem 12, which may measure a physical parameter P of the cartridge 3 such as a weight W or a length L, which has been changed due to the addition of the component 9.

[0106] Furthermore, an assembly station 5 may comprise a control subsystem 13 which is adapted to control the actuator subsystem 8, in particular an actuator 14 thereof, which performs a movement by which the component 9 is added to a cartridge 3.

[0107] A measurement signal 15 may be input to the control subsystem 13 from the measurement subsys-tem 12. The control subsystem 12 may be adapted to control the actuator subsystem 8 depending on the measurement signal 15. The measurement signal 15 may be an analog or digital representation of the physical parameter P.

[0108] In the embodiment shown in FIG. 1, the first assembly station 5 is a powder filling station 18, in which powder 10 is filled into the cartridge 3. This step is carried out in a filler subsystem 19.

[0109] Typically, the cartridge 3 has to satisfy very tight specifications. A cartridge which does not meet the specifications is a reject. For example, the weight W of the propellant 10 in the cartridge has to be within 15 mg for a 7.62 mm NATO cartridge. Cartridges 3 with too much or too few powder may not be used. The exact amount of propellant 10 is determined by the gas pressure which is to be generated in the chamber. The gas pressure not only depends on the amount of powder in the shell but also on the quality and granularity of the powder. Thus, the manufactured cartridges need to be controlled continuously during the manufacturing process by ballistic tests of production samples.

[0110] To maintain an exact filling of powder throughout the manufacturing process even over very long production periods, the powder filling station 18 comprises a measurement subsystem 12, which is adapted to measure the weight W of the propellant 10, which has been added as the new component 9 by the powder filling station 18. The measurement subsystem 12 of the powder filling station 18 comprises a net weighing apparatus 20a and a gross weighing apparatus 20b. The net weighing apparatus 20a is arranged in the assembly direction 6 before an actuator subsystem 8, which performs the actual filling of the propellant 10 into the shell 2. In the powder filling station 18, the actuator subsystem 8 comprises as an actuator 14 a dosing mechanism 21 for apportioning the powder and delivering it into the shell 2.

[0111] The gross weighing apparatus 20b is arranged in the assembly direction 6 preferably immediately behind the actuator subsystem 8.

[0112] In operation, the net weighing apparatus 20a determines a weight W.sub.N of the shell 2 before the powder filling, and the gross weighing apparatus 20b determines a weight W.sub.G of the shell 2 after the powder filling. The difference W.sub.G-W.sub.N of the two weight measurements W.sub.G, W.sub.N by the net and gross weighing apparatus 20a, 20b yields the actual weight of the powder 10 in the cartridge.

[0113] The control subsystem 13 of the powder filling station 18 is adapted to control the dosing operation of the dosing mechanism 21 depending on the measurement signal 15.

[0114] The measurement signal 15 may reflect a single momentary measurement value or an average of a plurality of subsequent or randomly picked momentary measurement values, as e.g. calculated using a sliding average. The amount of samples used for the sliding average may vary e.g. between 100 and 10,000. This results in a comparatively short time window, over which the average is calculated, given that an apparatus according to the invention may assemble between approximately 120 and 200 rounds of ammunition per minute.

[0115] More specifically, a storage member 22 may be provided in the control subsystem 13 which retains a representation of a target value T of the particular physical parameter P determined by the measurement subsystem 13. The target value T corresponds to the value of the physical parameter P as prescribed by the specification for the cartridges 3. The storage member 22 may be any one of a digital or analog electric or electronic memory, or a mechanic device such as a manipulator which is mechanically set to a certain position which represents the target value T.

[0116] In the case of the powder filling station 18, the storage member 22 may store a target weight W.sub.T for the powder in the shell as target value T. This target value T can be manually varied during the manufacturing process. For example, ballistic tests of sample products may necessitate a change of the target powder weight W.sub.T in order to maintain the specified gas pressure of the cartridge 3.

[0117] The deviation W.sub.T-(W.sub.G-W.sub.N) of the powder in a single shell from the target value W.sub.T or, if a sliding average is used, the average actual deviation

[00001]$\underset{n=1}{\overset{N}{.Math.}}.Math.\frac{W_T-\left(W_G-W_N\right)}{N}$

of N previous shells 2 is used by the actuator subsystem 8 to compensate the deviation. This can be done by a simple PID-control algorithm or any other control algorithm.

[0118] A reject station 23 may be arranged in the assembly direction 6 behind the assembly station 18 to remove reject cartridges which do not fulfill the specifications from the assembly process.

[0119] However, it is preferred that a storage and control subsystem 24 of the apparatus maintains a memory representation 26 of preferably all the cartridges currently being transported by the conveyor subsystem 4. In the memory representation, an ID, at least one physical property P, a reject flag R and/or its position in the apparatus 1 may be assigned to a particular cartridge 3. The handling of a particular cartridge 3 may depend on one or more of the values of in the representation 26.

[0120] For example, if a measurement subsystem 13 measures a physical parameter P which lies outside the specification, the respective cartridge 3 may be marked as a reject by setting the reject flag R and be ejected at the end of the assembly. The apparatus 1 may be adapted to not perform any operation on a cartridge 3 which is marked as reject. Further, the representation 26 of the array of cartridges in the conveyor subsystem 4 may mark specific types of cartridges, such as blanks which have been deliberately manufactured but for which some subsequent assembly steps, such as projectile insertion or crimping, need not be carried out or need to be carried out differently.

[0121] In addition to or alternatively to the powder filling station 18, the apparatus 1 may comprise a projectile insertion station 27 as an assembly station 5.

[0122] In the projectile insertion station 27, a projectile 11 is inserted into the shell 2 which has already been filled with propellant 10.

[0123] The projectile insertion station 27 comprises a measurement subsystem 13 which is configured as a cartridge length measurement apparatus 28. The cartridge length measurement apparatus 28 outputs as measurement signal 15 a representation of the actual length L of the cartridge 3.

[0124] The projectile insertion station 27 further comprises, as an actuator subsystem 8, a press-in subsystem 29. In the press-in subsystem 29, a projectile is delivered to, and pressed into the cartridge 3 with the help of an actuator 14. The actuator 14 may be force-controlled or path-controlled and terminate the press-in process once a target force or a target stroke has been reached.

[0125] The projectile insertion station 27 further comprises a control subsystem 13 which is adapted to control the force and/or the stroke of the press-in subsystem 29 depending on a deviation of the actual cartridge length L as measured by the cartridge measurement device 28 from the target value T, here a target length L.sub.T, stored in the storage member 22 of the control subsystem 13 of the projectile insertion station 27. If, for example, the cartridges 3 produced by the press-in subsystem 29 are too short, the control subsystem 13 may modify the stroke of the actuator so that the projectiles 11 are pressed to a lesser degree into the shells 2 than before.

[0126] Again, the deviation from a single measurement or from an average formed by a multitude of subsequent measurements can be taken to control the actuator subsystem 8. The various control signals and lines are designated with the reference numeral 30 in FIG. 1.

[0127] It is to be understood that each of the above-described steps of adding a component 9, measuring a physical property P of the cartridge 3, and rejecting a cartridge 3 are performed during a working cycle of the conveyor subsystem.

[0128] Starting from the above generic representation of the automated progressive ammunition assembly apparatus 1 and method, further designs and functions are described with reference to the remaining figures.

[0129] FIG. 2 shows a schematic perspective view of an automated progressive ammunition assembly apparatus 1. The apparatus 1 has a powder reservoir 39 and a reservoir 40 for the shells which preferably are already equipped with the primer.

[0130] As can be seen in FIG. 2, the conveyor subsystem 4 comprises a conveyor belt 41 which extends rectilinearly in the assembly direction 6 through the apparatus 1. Along the conveyor belt 41, the assembly 5 stations are lined up rectilinearly in the assembly direction 6. Again, each assembly station 5 completes one assembly step. For each assembly step, there is exact one assembly station 5.

[0131] The conveyor belt 41 is provided with compartments 42. Each compartment 42 is adapted to receive loosely a single cartridge 3 in a standing position. The bottom 43 of the cartridge 3 slides on a transport plane 44 of the apparatus 1. Thus, the cartridges 3 are simply pushed by the conveyor belt 41 in the assembly direction 6. Each compartment 42 is separated from the neighboring compartments 42 in the assembly direction 6 by a vertical rib 45. The conveyor belt 41 and the ribs 45 are preferably made from rubber and/or resin material. Vertically, the compartments 42 are open, preferably such that a shell 2 may fall through a compartment 42. Each compartment 42 defines a niche-shaped receptacle for a cartridge 3.

[0132] The conveyor belt 41 may be vertically spaced apart from the transport plane 44 so that the cartridges 3 project both vertically beneath and above the conveyor belt 41. The compartments 42 surround each cartridge 3 an three sides only, namely both in and against the assembly direction 6, and both perpendicular to the assembly direction 6 and perpendicular to a longitudinal axis 46 of the cartridges 3 standing on the transport plane 44. This can be seen in FIG. 3.

[0133] To avoid wear of the transport plane 44, a stationary slider bar 47 made from hardened and polished steel may be located in the transport plane 44 underneath the conveyor belt 41. The slider bar 47 may be exchanged if worn.

[0134] As shown in FIG. 3, at least one stationary retainer bar 48 may be used which extends parallel to the conveyor belt 41 to keep the cartridges 3 in the respective compartments, facing and closing the compartments 42. The retainer bar 48 is preferably located at a short distance from the conveyor belt, so that no pressure or friction-generating force is generated between the cartridges 3, the conveyor belt 41, and the retainer bar 48 during transport of the cartridges 3 in the assembly direction 6. The distance 49 between the retainer bar 48 and the conveyor belt 41 is small enough to prevent the cartridges from being moved out of the compartments. The distance 49 is preferably smaller than half the outer width D.sub.S of the shells 2, preferably even less than of the outer width D.sub.S.

[0135] The slider bar 47 and the retainer bar 48 may be combined monolithically to form a U- or L-shaped profile for guiding the cartridges 3 an at least two sides.

[0136] In the conveyor subsystem 4, the conveyor belt 41 is looped endlessly around two pulleys 50 of which the axes 51 are oriented vertically, i.e. parallel to the longitudinal axis 46 of the upright cartridges 3 in the conveyor belt 41. The loop 55 of the conveyor belt 41 defines a plane 56 which extends parallel to the transport plane 44 respectively.

[0137] It is to be noted that a drive 57 of the conveyor subsystem 4 is located above the transport plane 44. Thus, no openings are needed which extend through the transport plane 44 and in which the powdery propellant may gather during longer operations of the apparatus 1.

[0138] In the embodiment of FIG. 2, in a first step, the shells 2 which already may have been provided with a primer are fed and placed into the compartments 42 of the conveyor belt 41. This is done in a shell-feeding station 58. There, a feeder tube 59 may be extended from a shell reservoir 40 downwards to the location where a compartment 42 comes to rest between two subsequent transport cycles of the conveyor subsystem 4.

[0139] The shells 2 are fed through the feeder tube 59 passively by the force of gravity, and simply fall into the compartment 42. To allow this, the inner width D.sub.C of a compartment 42 should be larger than the largest outer width D.sub.S of the shell.

[0140] The feeding rhythm of the shell feeding station 58 is synchronized with the intermittent motion of the conveyor subsystem 4.

[0141] The shells 2 are then transported in the assembly direction 6 along a straight path to the powder filling station 18. There, the net weighing apparatus 20a determines the weight W.sub.N of each shell 2. The weight W.sub.N may be stored in the control subsystem 13 of the powder filling station 18 and/or in the representation of the assembly process in the storage and control system 24 of the apparatus 1.

[0142] The shells 2 are then transported to the filler subsystem 19, where powder in a dosed amount is filled into the shells. From there, the shells are transported in the assembly direction 6 to the gross weighing apparatus 20b, in which the weight W.sub.G of the powder-filled shell 2 is determined. The weight W.sub.N may be stored in the powder filling station 18 or in the storage and control subsystem 24.

[0143] In order to determine the actual weight of the amount of powder in the shell 2, the previously measured net weight W.sub.N from the net weighing apparatus 20a is subtracted from the gross weight W.sub.G as measured by the gross weighing apparatus 20b. The resulting weight difference W.sub.G-W.sub.N is then, as described above, compared to a target weight W.sub.T and the dosing mechanism 21 of the powder filling 18 is adjusted correspondingly in a feedback loop control.

[0144] The powder-filled shells 2 may pass an optional reject station 23, which removes shells 2 with a powder filling that does not meet the specification for the particular cartridge 3 to be manufactured. This reject station 23 may be omitted if, as described above, the conveyor control subsystem 24 keeps track of all the cartridges currently in the assembly process.

[0145] The powder-filled shells 2 are then transported in the assembly direction 6 to a projectile insertion station 27. In the projectile insertion station 27, projectiles (not shown) are fed from a projectile reservoir 60 to a location, where the powder-filled shells 2 come to rest between two subsequent transport cycles of the conveyor subsystem 4. If the cartridge below the projectile insertion station 27 is marked in the storage and control subsystem 24 as containing a non-reject powder-filled shell which should be provided with a projectile, the projectile insertion station 27 presses a projectile into the powder-filled shell.

[0146] In the assembly direction 6 preferably immediately behind the projectile insertion station 27, a cartridge length measurement apparatus 28 may be located. The cartridge length measurement apparatus 28 determines the length L of the cartridge 3 with the pressed-in projectile. This actual length is then compared to a target length L.sub.T as required by the specification for the cartridge 3 to be manufactured. If there is a deviation from the target value, the stroke of the projectile insertion station 27 is adjusted to compensate this deviation, as explained above.

[0147] Cartridges 3 which are either too long or too short to meet the specification may be removed from the conveyor subsystem 4 by a reject station 23 which is located downstream of the projectile insertion station 27. They may be marked as reject in the storage and control subsection 24 by setting the reject flag R for that particular cartridge 3.

[0148] A crimp station 65 may be provided, where the shell is crimped onto the projectile 11. The crimp station 65 may be located as shown between the projectile insertion station 27 and the length measurement apparatus 28.

[0149] Alternatively or additionally, another length measurement apparatus 28 may be located in the assembly direction 6 behind the crimp station 65 to control whether the length requirement is satisfied by the crimped cartridge 3. If the crimping process affects the length L of the cartridge 3, this may be compensated by adjusting the insertion stroke in the projectile insertion station 27. A difference can be calculated between the length L of the cartridge 3 before crimping and alter crimping in order to separate the effects of projectile Insertion from the effects of crimping and to provide adequate feedback control of the projectile insertion station 27 for both instances.

[0150] As can be seen in FIG. 2, all stations and subsystems are arranged above the transport plane 44 of the apparatus 1 or system 24 respectively. The apparatus 1 may comprise a dust-tight bulkhead 66 which separates a manufacturing space 67 from a bottom space 68. The bulkhead 66 may be formed by a massive steel or a metal sheet plate. Only the weighing apparatus 20a, 20b, notably its frame, may in one embodiment extend below the transport plane 44. The bulkhead 66 is spaced at a distance 61 from the transport plane so that the assembly stations 5 and all subsystems of the apparatus 1 are mounted on a mounting plane 62 of the apparatus 1.

[0151] The mounting plane 62 extends perpendicular to and above the bulkhead 66. Between the assembly stations 5 and the other subsystems of the apparatus 1 and the bulkhead 66 there is preferably an empty space 63 to allow easy access to the bulkhead 66 e.g. for cleaning. Only the weighing apparatus may extend into the empty space if a separated socket 100 for decoupling the weighing apparatus from the rest of the apparatus 1 is needed.

[0152] Next, the structure and function of a weighing apparatus 20a, 20b is explained with reference to FIGS. 4 to 6. The following description applies to both a net weighing apparatus 20a and a gross weighing apparatus 20b, which may be configured identically.

[0153] The weighing apparatus 20a, 20b comprises a weighing cell 69 which occupies the base area of a compartment 42. A bottom plate 70 of the weighing cell 69 is aligned flush with the transport plane 44. For weighing, a shell 2 is simply slid from the slider bar 47, which is provided with an opening or which is interrupted at this position, onto the bottom plate 70 during a transport cycle.

[0154] A transport channel 64 which is formed by the slider bar 47 and the retainer bar 48, which are monolithically combined and through which the shells 2 are transported, is clearly visible in FIG. 4.

[0155] For an accurate measurement of the weight, it is important that the shell 2 does not contact the compartment 42 or any other part of the apparatus 1, such as the slider bar 47 or the retainer bar 48, which does not belong to the weighing apparatus 20a, 20b. For this, a centering mechanism 71 is provided, which automatically moves the shell 2 away from contact with the compartment 42 and preferably centers the shell 2 an the bottom plate 70 of the weighing cell without moving the cartridge out of the compartment 42. This is preferably done automatically and passively, i.e. without any actuators requiring external power, during a transport cycle. The centering mechanism 71 may comprise a spring drive 72, which is automatically loaded and operated by the shell 2 being trans-ported onto the weighing cell 69.

[0156] In the embodiment of FIGS. 3 and 4, the spring drive 72 comprises at least one spring arm 73 which is adapted to be resiliently deflected in a direction parallel to the transport plane 44 and perpendicular to the assembly direction 6 by the shell 2 upon its transport onto the weighing cell 69. The spring arm 73 may be configured to be bent elastically upon deflection or be hinged using spring-loaded joints. The spring arm 73 is provided with a centering bevel 74, which may be V- or U-shaped in a cross-section parallel to the bottom plane. The bottom 75, where the width of the centering bevel 74 is widest, is located vertically above the center of the bottom plate 70. The bottom 75 may be rounded and in particular be formed complementary to the shell 2 to allow a snug fit.

[0157] One or two pairs of spring arms 73 may be provided on the opposite sides of the conveyor belt 41 and each of the spring arms may be provided with a centering bevel 74. The conveyor belt 41 may extend between each pair of spring arms 73. An upper pair 76 of spring arms may be adapted to engage a neck 77 of a shell 2, another, lower, pair 78 of spring arms may be adapted to engage the shell at its base shortly above the lower rim 79 of the shell 2.

[0158] The weighing cell 69 and the centering mechanism 71 operate as follows.

[0159] If, in a transport cycle of the conveyor subsystem 4, a shell 2 is pushed from the previous resting position 81 onto the weighing cell 69, the spring arms 73 are pried apart from each other by the shell 2 and thus generate a force which tries to move the spring arms 73 back towards each other. To allow easy entrance of the shell 2 into the centering bevel 74 between the spring arms 73, an entry bevel 82 may be provided, which provides an entrance opening 83 which opens wide against the assembly direction 6 and, in the assembly direction 6, narrows until the centering bevel 74 be-gins.

[0160] Once the shell 2 has moved past the entry bevel 82 and enters the centering bevel 74, the force exerted by the pried-open spring arms 73 pushes the shell automatically into the bottom 75, where the centering bevel 74 has its largest inner width. This happens in a quick snapping motion of the spring arms 73.

[0161] In the bottom 75 of the centering bevel 74, the shell is held spaced apart from the compartment 42 when the conveyor subsystem 4 has reached the next working cycle. For this, the weighing cell 69 with the at least one spring arm 73 has to be aligned with the resting position 81 of the compartment 42 on the location of the weighing cell 69.

[0162] With the shell 2 resting in the bottom 75 of the centering mechanism 71, the weight measurement can take place during the working cycle of the conveyor subsystem 4. As the spring arms 73 are part of the weighing cell 69, they do not falsify the weight measurement.

[0163] In the next transport cycle, the conveyor belt 41 first moves until it abuts the shell 2 at its surface facing away from the assembly direction 6. It then continues to push the shell 2 from the weighing cell 69 and out of the centering mechanism 71 by, again, prying apart the spring arms 73. To allow a smooth exit of the shell 2 from the centering mechanism 71, an exit bevel 84 may be provided which has an exit opening 85 that widens in the assembly direction 6. The geometry of the exit bevel 84 may be the same as for the entry bevel 82, except that directions are reversed.

[0164] To allow a smooth transition from the entry bevel 82 or the exit bevel 84 into the centering bevel 74, the transition zone between the two may be rounded.

[0165] Both the net weighing apparatus 20a and the gross weighing apparatus 20b acquire, during the same working cycle, the weight of two different shells 2. At the same time, another shell may be filled with powder. In order to determine the actual powder weight of a shell 2, only the net weight and the gross weight of one particular shell may be considered. This is facilitated by using the representation 26 of the current manufacturing process in the control and storage subsystem 24.

[0166] In FIG. 7, part of the powder filling station 18 is shown. The dosing mechanism 21 of the powder filling station 18 comprises an outer centering tube 86 with an inner centering bevel 87, and an inner feeder tube 88. The centering tube 86 and the feeder tube 88 are aligned coaxially and may be rigidly connected so that they are moved together. In the shown embodiment, however, the feeder tube 88 is stationary with respect to the shell 2 and the centering tube 86 may be moved independently of the feeder tube 88 in the vertical direction.

[0167] For filling a shell 2 with propellant 10, the centering tube 86 is moved vertically, until the centering bevel 87 hits an upper rim 89 of the shell in the compartment 42 underneath the dosing mechanism 21. The centering bevel 87 automatically centers the shell underneath the centering tube 86. For this, an outer diameter D.sub.BO of the centering bevel 87 may be larger than the inner width D.sub.C of the compartment. An inner diameter D.sub.BI of the centering bevel 87 corresponds to the outer width D.sub.S of the shell 2 so that the centering tube 86 may slide over the shell 2 and provide a dust-tight sealing during the filling process. Of course, it is also possible that the outer diameter of the centering tube 86 and the centering bevel 87 respectively correspond to an inner diameter of the shell 2, so that the centering tube 86 may slightly enter the shell.

[0168] Once the shell 2 is inserted in the centering tube 86 and thus centered within the compartment 42, the propellant 10 is falling through the feeder tube 88 into the shell 2.

[0169] The amount of propellant 10 is determined by the size of a dosing chamber 90. The size of the dosing chamber 90 is adjusted by the dosing mechanism 21 which uses a stepper motor 91 to move one wall 92 of the dosing chamber 21. The stepper motor 91 is moved together with the dosing chamber 90 in a reciprocating motion 93 which motion successively aligns the dosing chamber 90 with the powder reservoir 39 for filling and with the feeder tube 88 for discharging the powder into the shell 2. The size of the dosing chamber 90 is adjusted as described above depending on the values W.sub.N, W.sub.O and W.sub.T.

[0170] In FIG. 8, a system 110 is shown consisting of two apparatuses 1, which are paired together side-by-side having parallel assembly directions.

[0171] The system 110 is easily scalable in its output and versatility, because the layout of the apparatus 1 allows to simply group two or more apparatuses 1 together in parallel. In the system 110, several apparatuses 1 may share a common powder reservoir 39, a common shell reservoir 40 and/or a common projectile reservoir 60. The assembly direction 6 is preferably the same so that the assembly stations 5 are at the same locations with respect to the assembly direction 6 in the parallel apparatus 1. The apparatus 1 may be arranged such that the transport planes 44 are at the same distance from the bulkhead 66.

[0172] FIG. 9 depicts a further preferred embodiment of the apparatus 1 according to invention for the manufacturing of ammunition. The apparatus 1 depicted in FIG. 9 corresponds to the preferred embodiment of an apparatus depicted in FIG. 2, illustrates however an alternative mounting of the assembly stations 5 as well as the conveyer system 4 to the mounting plane 62 of the apparatus 1. The working principle for the apparatus 1 is the same as detailed for the apparatus depicted in FIG. 2. Shells 2 are supplied from the shell reservoir 40 into compartments 42 of the conveyer belt 41. In the powder filling station 18 the ammunition powder is filled into the shells 2. The amount of powder is controlled by means of a feedback control mechanism that is based on the weight measurements of the shell 2 prior to and after the powder dosing using the weighting apparatus 20a and 20b. Subsequently the cartridges 3 are moved along the sectionwise linear conveyer belt 41 and are worked upon by additional assembly stations 5 that are arranged in a rectilinear manner along the assembly direction 6. The projectile insertion station 27 serves to press the projectiles 11 into the shells 2. To this end the projectiles 11 are preset into the shells 2 and subsequently pressed-in using the press-in subsystem 29. By means of a cartridge length measurement apparatus 28 the projectile insertion can be monitored and adapted by a feedback control. As shown in FIG. 9 the assembly stations 5 as well as the conveyer system 4 are attached to the mounting plane 62 such that an empty space 63 is formed between these components of the apparatus 1 and the upper surface of the horizontal bulk head 66. The assembly stations 5 and the conveyer system 4 are therefore situated in a manufacturing space 67 above the bottom space of the apparatus 68. The horizontal bulk head 66 may be preferably made of metal and is preferably constructed in a dust-tight manner: Only the weighing apparatus 20a and 20b may extend into the bottom space 68. However the weighting cells 69 are also concealed in a dust-tight manner. In the preferred embodiment ammunition powder will remain on the upper surface of the bulk head 66 and can be easily removed due to the empty space 63. The attachment of the assembly stations 5 to the mounting plane 62 allows for a fast mounting and demounting of the assembly stations 5. The preferred embodiment of the apparatus 1 is therefore characterized by a modular design allowing for a high degree of functional flexibility.

[0173] FIG. 10 shows a schematic view of a further preferred measurement subsystem 12 for measuring the weight of a cartridge comprising a rotatable transport device. In FIG. 10 two measurement subsystems 12 are shown side-by-side as it is preferably the case for two conveyor subsystems 4 arranged side-by-side for a system of two apparatus assembled parallel and next to each. However, the illustrated mechanism of the preferred measurement subsystem 12 comprising a rotatable transport device 121 equally applies to an apparatus 1 with a single conveyor subsystem 4. In the preferred embodiment the conveyor subsystem 4 comprises a conveyor belt 41 comprising compartment 42 to receive the shells 2 which are separated by vertical ribs 45. The shells 2 are moved through the apparatus by means of said conveyor belt 41 pushing the shells 2 within a transport guide 48. As explained with respect to FIG. 4-6 in one embodiment of the invention the weighing cells 69 are installed in line with the conveyor subsystem 4, wherein it is preferred to use a centering apparatus to allow to separate the cartridges from the conveyor subsystem 4 in order to arrive at more precise weight measurements. FIG. 9 depicts a particularly preferred alternative solution to arrive at a highly precise weight measurement. Instead of installing the weighing cells 69 in line with the conveyor subsystem 4, i.e. in line with the conveyor belt 41 and the transport guide 48. The embodiment of the weighing apparatus 20a, 20b of FIG. 10 comprises weighing cells 69, whose measurement position is outside the conveyor belt 41. In order to move the shells 2 from the conveyor belt 41 to the respective weighing cell 69, the measurement subsystem 12 comprises a transport device 121, which is preferably rotatable. It is particularly preferred that the rotatable transport device 121 comprise a lower transport wheel 123 and an upper transport wheel 122 that comprise niches or compartments shaped to receive the shells 2. In a preferred embodiment the weighing procedure is conducted as follows.

[0174] The shells 2 are transported within the transport guide 48 by means of the conveyor belt 41 towards the transport device 121 comprising rotatable upper and lower transport wheels 123, 122. The rotation of the transport wheels 122, 123 is synchronized with the movement of the conveyor belt 41 such that a single shell 2 passes from one of the compartments 42 of the conveyor belt 41 to a corresponding compartment of the transport wheels 122, 123. As it is the case for the linear movement of the conveyor belt 41 the rotation of the transport wheels 122, 123 is preferably intermittently comprising a transport and a working cycle. By means of the intermittent rotation the shells 2 are moved on top of a transportation plane towards a first weighing cell 69 of the net weighing apparatus 20a. It is preferred that the weighing cell 69 is not mechanically connected to the conveyor subsystem 4. For instance the conveyor subsystem 4 may be mounted to a base frame or mounting plane (not shown in FIG. 10), while the weighing cells 69 is situated on top of a support 120, which is mounted on a free standing socket 100. Thereby it can be efficiently avoided to transmit vibrations of the conveyor subsystem 4 or base frame to the weighing apparatus.

[0175] To this end it is particularly preferred that after the shell 2 is moved onto the measurement position of the weighing cell 69 the transport device 121 is rotated slightly backwards in order to ensure that during the measurement the shell 2 is not in contact with the transport wheels 122, 123. This procedure proved to allow for a particular precise measurement of the net weight of the shells 2. After the measurement the transport device 121 continuous to move the shells 2 towards a position for the filling of ammunition powder. At this position the filler subsystem (not shown in FIG. 10) of the powder filling station adds the ammunition powder to the shell 2. Subsequently the transport wheels 122, 123 continue to move the shell 2 filled with ammunition powder towards a second weighing cell 69 of the gross weighing apparatus 20b. It is likewise preferred that prior to the gross weight measurement the transport wheels 122, 123 are moved slightly backward in order to ensure a precise measurement that is not compromised by the shells 2 touching the transport wheels 122, 123. Throughout the operation of the apparatus the transport wheels 122, 123 hence perform an intermittent rotation along the rotation direction with a transport and working cycle, wherein before the working cycle (and thus a measurement) starts the rotation is shortly reverted. Afterwards the shells 2 are further moved along by means of the rotating transport device 121 and handed back over to the conveyor belt 41 and transport guide 41 to continue the processing along the assembly line.

[0176] It is preferred that the rotation of the transport wheels is achieved by means of a servo motor allowing for a particular precise motion. Moreover as seen in FIG. 10 it is particular preferred that each of the weighing cells 69 are installed on separate supports 120 which may be mounted onto a common socket for the weighing apparatus 20a, 20b. In case of an embodiment with two conveyor subsystems 4, the four weighing cells 69 of the two net weighing apparatus 20a and two gross weighing apparatus 20b are preferable installed onto the same socket 100. It is preferred that said socket 100 is mechanically disconnected from the rest of the base frame for the apparatus, which may as previously described comprise a bulkhead and a mounting plane (not shown in FIG. 10).

REFERENCE NUMERALS

[0177] 1 automated progressive ammunition assembly apparatus [0178] 2 shell [0179] 3 cartridge [0180] 4 conveyor subsystem [0181] 5 assembly station [0182] 6 assembly direction [0183] 8 actuator subsystem [0184] 9 component [0185] 10 propellant/powder [0186] 11 projectile [0187] 12 measurement subsystem [0188] 13 control subsystem [0189] 14 actuator [0190] 15 measurement signal [0191] 18 powder filling station [0192] 19 filler subsystem [0193] 20a net weighing apparatus [0194] 20b gross weighing apparatus [0195] 21 dosing mechanism [0196] 22 storage member of control subsystem [0197] 23 reject station [0198] 24 storage and control subsystem [0199] 25 storage section of conveyor control subsystem [0200] 26 representation of cartridges presently in storage section of the conveyor subsystem [0201] 27 projectile insertion station [0202] 28 cartridge length measurement apparatus [0203] 29 press-in subsystem [0204] 30 control signals [0205] 39 powder reservoir [0206] 40 shell reservoir [0207] 41 conveyor belt [0208] 42 compartment of conveyor belt [0209] 43 bottom of cartridge or shell [0210] 44 transport plane an which cartridges stand upright during transport [0211] 45 ribs between compartments [0212] 46 longitudinal axis of cartridge [0213] 47 slider bar [0214] 48 retainer bar [0215] 49 distance between retainer bar and conveyor belt [0216] 50 pulley for conveyor belt [0217] 51 axis of pulley [0218] 55 loop of conveyor belt [0219] 56 plane of conveyor belt loop [0220] 57 drive of conveyor subsystem [0221] 58 shell feeding station [0222] 59 feeder tube [0223] 60 projectile reservoir [0224] 61 distance between transport plane and bulkhead [0225] 62 mounting plane [0226] 63 empty space [0227] 64 transport channel [0228] 65 crimp station [0229] 66 dust-tight bulkhead [0230] 67 manufacturing space of apparatus [0231] 68 bottom space of apparatus [0232] 69 weighing cell [0233] 70 bottom plate of weighing cell [0234] 71 centering mechanism of weighing cell [0235] 72 spring drive [0236] 73 spring arm [0237] 74 centering bevel of centering mechanism [0238] 75 bottom of centering bevel [0239] 76 upper pair of spring arms [0240] 77 neck of shell [0241] 78 lower pair of spring arms [0242] 79 rim of the primer [0243] 80 primer of cartridge [0244] 81 resting position [0245] 82 entry bevel of centering mechanism [0246] 83 entrance opening of entry bevel [0247] 84 exit bevel of centering mechanism [0248] 85 exit opening of exit bevel [0249] 86 centering tube [0250] 87 inner centering bevel of centering tube [0251] 88 feeder tube [0252] 89 upper rim of shell [0253] 90 dosing chamber [0254] 91 stepper motor [0255] 92 wall of dosing chamber [0256] 93 reciprocating motion [0257] 100 socket of weighing apparatuses [0258] 110 system comprising at least two apparatuses [0259] 120 support for weighing cells [0260] 121 transport device [0261] 122 upper transport wheel [0262] 123 lower transport wheel [0263] 124 servo motor for the transport device [0264] D.sub.C inner width of compartment [0265] D.sub.S outer width of shell [0266] D.sub.BI inner width of centering bevel of centering tube [0267] D.sub.BO outer width of centering bevel of centering tube [0268] L.sub.T target length of the cartridge [0269] L measured length of the cartridge [0270] ID identification number of the cartridge [0271] P physical parameter of cartridge [0272] R reject flag [0273] target value [0274] W weight [0275] W.sub.G gross weight [0276] W.sub.N net weight [0277] W.sub.T target weight