Background of the Invention
This invention relates to weapon systems and in particular to apparatus for feeding either linked or linkless rounds to a rapid-fire weapon. While the invention is described in particular detail with respect to the linkless ammunition in a rapid-fire weapon system, those skilled in the art will recognize the wide applicability of the principles disclosed hereinafter.
Rapid-fire weapon systems, particularly when installed in an air-borne carrier, present heretofore unresolved problems in their operation. In general, the firing weapon of an air-borne carrier is contained in a gun mount or turret located at one part of either a fixed or rotary wing aircraft, and the magazine supply for ammunition rounds is located some distance from the gun mount in another part of the aircraft. Mere separation of the weapon and magazine is troublesome. For example, the length of the supply line between the magazine and the weapon can be so great that the pulling force of the weapon may be insufficient to draw the rounds from the magazine container due to the conveyor length, and, hence, the weight of the conveyor along the supply path.
The prior art does deal with the conveyor length problem and offers a number of problem solutions. In general, the prior art provides means for driving either the magazine or the conveyor at a rate comparable to the weapon demand rate. While these prior art solutions work for their intended purposes, the solution themselves often raise additional difficulties. Thus, high power is required to overcome the inertia of the magazine when the magazine is driven in conjunction with the demand rate of the weapon. Since the firing weapon demand rate varies between instantaneously high and instantaneously low, depending on whether the firing mechanism is held on or released, rather complex systems are needed to bring the mazazine first to a high feed rate and then to bring it to rest after the gun shuts down. Magazine drive is further complicated when the weapon is fired in short but repeated bursts. Extremely complex devices are required for drive control under these conditions. If the magazine itself is not drivable, some form of powerdriven sprocket is utilized in conjunction with a stationary magazine to accomplish the same purpose. Although a power driven sprocket requires less driving power, it requires the same type of complex control devices. Other weapon system designs rely merely on the pull of the gun to move the rounds to the firing chamber.
While prior art solutions to the problem of feeding a rapid-fire gun are acceptable in certain application installations, their use with a rapid-fire weapon movable in elevation and azimuth planes, for example, particularly where the system is installed in an air borne carrier, has presented additional unresolved difficulties. In air borne weapon applications, individual rounds from the magazine are transported to the gun mount by some type of conveyor or other rounds carrier, usually contained within a flexible chute. These flexible chutes commonly are capable of motion in both elevation and azimuth planes. The chute contortions dictated by required elevation and azimuth angles for proper gun mount flexibility result in ever changing dynamic conditions in the ammunition, chutes and conveyors. This in turn has resulted in increased weapon reliability problems, because flexible chutes have a number of inherent deficiencies. For example, friction between the conveyor or the ammunition proper and the feed chute can vary as the chute twists and rolls or expands and contracts in following the motion of the weapon. Consequently, the force required to either drive or pull the ammunition varies, and changes the power requirements for the drive mechanism. Because of the motion of the weapon necessarily acts on the flexible chute utilized, the chute may collapse or extend axially during weapon motion. Compression or extension causes the ammunition flow path to change its dimensional length, which generally leads to a compressive or tension force being applied to the conveyance means or the ammunition. Compression or tension forces on the chute leads to dimensional changes in the chute which in turn causes a velocity change for the ammunition within the feed chute. Compression and tension forces on the chute, in addition to increasing the friction between the ammunization and chute, also can cause separation of either the ammunition conveyance means or the chute itself.
Most prior art weapon systems utilize a common power source both to power the weapon's storage magazine and to power the associated feed system components in order to match the velocity and acceleration requirements of the firing weapon. Commonly, use of a common power source leads to utilization of oversized power devices in order to meet all system contingencies and complex control means for regulating the power source. This combination of factors leads to increased weight, inertia, complexity and expense of the weapons system.
The invention disclosed hereinafter overcomes these prior art deficiencies with a novel device or mechanism that has a fixed, non-flexible chute connected between the input side of the device and the output of the magazine. The fixed, non-flexible chute and associated conveyor brings individual rounds from a conventional storage magazine to the entrance of the device. The device has its entrance anchored to a fixed structure. The output end of the device, however, is designed to rotate with the weapon or weapon mount. While a flexible chute still is connected between the output side of the device and the firing weapon, that chute need be movable only in the elevation plane of the weapon. Three power inputs are used in connection with the invention. One input from the weapons's magazine correlates the input to the mechanism with the magazine feed rate. The exit power from the device is obtained from the weapon's demand. The third input is obtained from weapon mount rotation. Weapon mount rotation is used to adjust rounds within the device. This precludes the necessity of changing round position in either the fixed chute connected between the mechanism input and the magazine output or in the flexible chute connected between the output of the mechanism and the weapon.
The mechanism includes storage means and a differential for transferring rounds in the storage means. The differential adds and subtracts velocities to match the input velocity to the mechanism and the output velocity from the mechanism to the required weapon feed rate. By utilizing the storage capacity within the device, it is possible to permit the weapon to fire at full rate without requiring the magazine to match this rate in phase with the weapon. Consequently, reduced power is required to accelerate the magazine upon initiation of weapon operation. The elimination of chute motion about the azimuth plane permits the use of a fixed or rigid type feed chute for substantially the entire chute length, which in turn reduces cost in the overall system and provides increased reliability by elimination of potential jam or high friction points inherent in flexible chuting, caused by chute motion. The system described hereinafter also will allow the gun to cease fire while the reservoir provided in the mechanism absorbs ammunition and refills to a correct level before requiring the magazine to halt. This action again may be accomplished out of phase from the weapon.
One of the objects of this invention is to provide a simplified weapon system for a rapid firing weapon.
Another object of this invention is to provice means for correlating a rapid fire weapon demand rate for ammunition and the output rate of an associated magazine.
Another object of this invention is to provide a correlating device utilizing differential means for adjusting input and output velocities from the device.
Yet another object of this invention is to provide a correlating means mounted to and rotatable with a gun turret.
Yet another object of this invention is to provide a weapon system for a rapid fire gun having reduced power requirements for the drive of an associated magazine.
Other objects will be apparent to those skilled in the art in light of the following description and accompanying drawings.
Summary of the Invention
In accordance with this invention, generally stated, a rapid fire weapon system is provided with intermediate correlating means for matching the output rate of the magazine with the input rate of the weapon. The correlating means includes a housing having a first fixed part, a second rotatable part, and a rounds reservoir interleafed above and below a differential means for summing magazine output and weapon input rates. The combination of reservoir and differential enables the correlating means to meet gun demand simultaneously, in phase, and to treat azimuth rotation of the weapon mounting merely as one factor in differential position. Because the correlating means eliminates azimuth motion in the ammunition feed system, the conveyor and chute utilized in conjunction with the weapon also in less complex, and lower in both cost and weight.
Breif Description of the Drawings
In the drawings, FIG. 1 is a diagrammatic view in perspective, partly broken away, of a weapon system utilizing one illustrative embodiment of rotary differential ammunition reservoir of this invention;
FIG. 2 is a view of perspective, partly broken away, of a second illustrative embodiment of a rotary differential ammunition reservoir compatible with the weapon system of FIG. 1;
FIG. 3 is a diagrammatic view illustrating the operation of the rotary differential ammunition reservoir of FIG. 2;
FIG. 4 is a series of exploded views correlating the diagrammatic view of FIG. 3 with the structural embodiment of FIG. 2;
FIG. 5 is a diagrammatic view illustrating operation of the combined components of FIG. 4;
FIG. 6 is a top plan view, partly broken away, of the rotary differential ammunition reservoir shown in FIG. 2; and
FIG. 7 is a sectional view taken along the line 7--7 of FIG. 6.
Description of the Preferred Embodiment
Referring now to FIG. 1, reference numeral 1 indicates the rotary differential ammunition reservoir of this invention illustratively shown as forming a part of a weapon system 2. The weapon system 2 includes a storage magazine 3 having an output side connected to a conveyance means 4. The conveyance means 4 includes a chute 5 covering a conventional ammunition conveyor 6, shown in FIG. 2. The conveyor 6 is an endless loop type having a forward path 60 and a return path 61. As used hereinafter, the terms conveyance means 4 and chute 5 are intended to encompass both of the paths 60 and 61.
A rapid fire weapon 7 is mounted in a gun turret 10 for movement in an elevation plane 8 and in an azimuth plane 9. The weapon 7 and gun turret 10 are conventional and a variety of rapid fire weapons and their associated gun turrets are compatible with the broader aspects of this invention.
The reservoir 1 is mounted to the turret 10 by any convenient method. As is explained in detail hereinafter, a portion of the reservoir 1 is rotatable with the turret 10 in the azimuth plane 9. A partially flexible end 11 terminates one side of the conveyance means 4. A second end 47 of the conveyance means 4 also is partially flexible. The flexible ends 11 and 47 are desirable in order to permit easy reloading of the magazine 3, and to provide easy connect and disconnect functions between the conveyance means 4 and the reservoir 1 or the magazine 3 should any malfunction occur in those portions of the system 2. However, once in position, the ends 11 and 47 of the conveyance means 4 function as fixed elements in the operation of the system 2.
The reservoir 1 has an input side 12 and an output side 13. The output side 13 is connected to the input of the weapon 7 by a conveyance means 14. Conveyance means 14 includes a chute 62 covering a conventional conveyor, not shown, which also commonly has a forward and a return path arranged in an endless loop, similar to conveyance means 4. The chute 62 also is flexible in the sense of the flexible ends 11 and 47 of conveyance means 4. That is, the conveyance means 14 need be movable with the weapon 17 only in one plane, the elevation plane 8, as it may rotate in the azimuth plane 9 with the weapon 7 and a portion of the reservoir 1. The conveyance means 14, besides being relatively short in overall length, is more simple in construction and lower in cost than flexible chutes movable in two planes commonly used in prior art devices.
The weapon system 2 may be installed on any convenient launch platform 15. Launch platform 15 is illustrated in phantom lines as an aircraft structure, of either a rotary or a fixed wing type. The magazine 3 is placed at any convenient location on the launch platform 15 and the conveyance means 4, a substantial part of which is constructed from a non-flexible chute material, is interconnected between the magazine and the input 12 to the reservoir 1. Because the major portion of the conveyance means 4 is a non-flexible chute and the entire length of the conveyance means 4 operates as a non-flexible chute, problems inherent in prior art systems related to chute dynamics are eliminated and the weapon system 1 exhibits high reliability with little down time because of ammunition jams or chute separations.
Referring now more specifically to FIGS. 2 and 7, the reservoir 1 includes a housing 16 having a first or upper stationary housing part 17 and a lower rotatably mounted plate 18, which define a chamber 49 in their intermounted position.
The stationary part 17 includes a top wall 50 and an integrally formed, downwardly extending side wall 51. The lower extremity of the side wall 51 has a flange 52 extending radially outwardly from it. The flange 52 seats a bearing means 32 which permits rotation of the plate 18 with respect to the part 17. The part 17 is attached to convenient stationary structure as illustratively shown at 53. Attachment may be made by conventional threaded fasteners, for example. Top wall 50 has a central hub area 54 which, together with a similar hub 55 in the plate 18, provide passage for various conventional gun turret 10 power drives and related components which form no part of this invention and are not described in detail. The top wall 50 preferably is a lattice structure having a plurality of radial spokes 58 extending outwardly from the hub area 54 to the side wall 51 and a series of annular ribs 56 supportively attached to the spokes 58. The reservoir 1 shown in FIGS. 1 and 2 are identical with the exception of the lattice construction of the stationary part 17. The lattice design gives better access and visibility to the internal components of the reservoir 1 and is preferred for this reason. An input sprocket 19 is rotatably mounted to the stationary housing part 17.
The input sprocket 19 shown is a six station, two wheel device of conic design. The sprocket 19 is designed to provide smooth transfer of an individual round 63 from the conveyance means 4 to the reservoir 1. A plurality of scoop cams 64 may be utilized as an aid in round transfer.
Individual rounds 63 are transferred from the storage magazine 3 to the conveyance means 4 which in turn transports the rounds 63 to the upper housing part 17 of the reservoir 1. Since the upper housing part 17 is attached to a fixed structure and is itself not movable, the chute 5 which guides the conveyor 6 can be of rigid type construction. It should be reiterated that this feature of fixed chuting greatly enhances the reliability of the feed system. Simply stated, fixed chuting represents a constant conveyor length and subsequently constant tension on the conveyor loop. Experience has shown that reliability and power requirements of a weapon supply system are extremely sensitive to changes in conveyor tension. A slack conveyor means a change in linear pitch, i.e., links folding, and therefore a loss of positive control of the conveyor loop. On the other hand, a tight conveyor requires more power due to resultant high friction loads between the conveyor and the chuting.
The conveyor 6 of the conveyance means 4 approaches the input sprocket 19 of the reservoir 1 in a plane tangent to the line of revolution which forms the conic of the sprocket 19. The conveyor plane also is curved toward the apex of the sprocket 19 cone to match velocities at the tangency plane. It should be noted that the round/conveyor spacing at the pull line of the conveyor 6 remains constant and differences in the linear velocity between the nose and butt of an individual round 63 is achieved by canting the conveyance means 4 about a point on the conveyor pull line. The phrase "pull line" is a term of art and refers to the longitudinal axis of the ammunition conveyor. Achieving this geometry to the tangency line with the sprocket is accomplished by simply curving the cute end 11 as shown in FIG. 1. Individual ones of the rounds 63 are transported by the sprocket 19 from the conveyance means 4 through the stationary housing part 17, to an upper transfer wheel 20.
The upper transfer wheel 20 generally is a flat, annular plate having a plurality of tangs 22 which engage individual ones of the rounds 63 along an extractor groove 24 in the rounds. The tangs 22 are formed integrally with a plurality of fingers 25 which extend radially outwardly from a central hub 26 of the upper transfer wheel 20. Lateral control of the rounds 63 within the reservoir 1 is maintained by a pair of concentric rings 65 formed on each side of a differential rounds carrier 28 and a ring 66 which is integrally formed with the stationary housing part 17. These rings combine to provide a stable, three point support of the round.
The differential rounds carrier 28 is annular in plan and includes an outer and inner rim 67 and 68 which have the rings 65 integrally formed therewith. The rims 67 and 68 are journaled for rotation with respect to an outer support structure 69 along bearing means 70 and with respect to an inner support structure 71 along a bearing means 72. A transfer sprocket 29 is mounted to the differential rounds carrier 28 between the rims 67 and 68 and is rotatable with respect to the carrier 28. The rings 65, which as previously indicated, are integrally formed with the rounds carrier 28, enable the rounds 63 to be canted as they approach the transfer sprocket 29. Canting the rounds 63 allows a smooth transition of the rounds from the upper transfer wheel through the differential rounds carrier to the lower transfer wheel, minimizing the acceleration of the round during transition. The differential rounds carrier 28 is symmetrical in a horizontal plane. That is, the round is canted as it approaches the transfer sprocket 29 and is straightened as it travels away from the sprocket on the opposite, lower side of the rounds carrier 28. As is later explained, the reservoir 1 is symmetrical about and below the differential rounds carrier 28 and the same guidance control features apply to the lower half of the reservoir 1.
Mounted beneath the differential rounds carrier is a lower transfer wheel 30. The lower transfer wheel 30 is similar to the upper transfer wheel 28 and includes the central hub 26 having a plurality of the fingers 25 extending radially outwardly from it. The upper and lower transfer wheels are identical and may be interchanged with one another during the manufacture of the reservoir 1. The lower transfer wheel 30 receives the rounds 63 from the transfer sprocket 29 and carries them to an output sprocket 31. Output sprocket 31 is mounted to the lower rotatably mounted plate 18 and is rotatable both with and with respect to plate 18. The plate 18 includes a ring 73 for supporting the rounds 63. While preferably described as a distinct part, those skilled in the art will recognize that the plate 18 may in fact comprise the top wall of the gun turret 10, if desired.
The sprocket 31, like the sprocket 19, is a six station, two wheel device of conic design. The conveyance means 14 also is curved toward the apex of the sprocket 31 to match velocities at the tangency plane. Again, this geometry is achieved merely by curving the conveyance means 14 as shown in FIG. 1.
To recapitulate the functional operation of the reservoir 1 in its simplest terms, rounds 63 are transported from the magazine 3 via the conveyance means 4 to the input sprocket 19 of the reservoir 1. The rounds are transferred from the conveyor to the upper transfer wheel 20 which serves as one half of the reservoir for the rounds 63. The rounds 63 in turn are transferred from the upper transfer wheel 20 to the lower transfer wheel 30 by the transfer sprocket 29 of the differential rounds carrier 28. The lower transfer wheel 30 transfer the rounds 63 to the output sprocket 31 of the reservoir 1 at which point the rounds are placed into the gun conveyance means 14 for transport to the rapid fire weapon 7.
To achieve this operation, the lower plate 18 is rotatably mounted with respect to the stationary housing part 17 along the bearing means 32. The lower transfer wheel 30 is rotatably mounted with respect to the plate 18 along a bearing means 33. Transfer wheel 30 also is rotatably mounted with respect to the differential rounds carrier 28 along a bearing means 34. The differential rounds carrier 28 in turn is rotatably mounted with respect to the upper transfer wheel 20 along a bearing means 35. Finally, the upper transfer wheel 20 is rotatably mounted with respect to the stationary housing part 17 along a bearing means 36.
A system of internal gears is utilized in conjunction wth the upper transfer wheel 20, the lower transfer wheel 30 and the differential rounds carrier 28 to enable the reservoir 1 to correlate weapon demand rate with magazine output rate. The reservoir 1 gear system may be considered a rack and pinion differential in which the racks used are infinitely long, i.e., are plantary gears. Basically, a differential device is simply an adding machine that can continuously produce difference or sum values from two inputs that may themselves be changing quite rapidly. In the weapon system 2, the two inputs are the magazine feed rate and the demand rate of the weapon 7. As indicated above, a third output, the azimuth location of the turret 10, is treated merely as a second source or a second indication of weapon demand rate. In the gear system of the preferred embodiment, the output sprocket 31 receives weapon 7 demand rate information along a gear 37. The sprocket 31 is rotatably mounted to the plate 18 along a pair of bearings 38 and 39 respectively. The gear 37 is coupled to and transmits weapon demand to the lower transfer wheel 30 through a gear 40 interconnected to a first side of the transfer wheel 30. A second side of the transfer wheel 30 has a gear 41 attached to it. Gear 41 is coupled to a gear 42. The gear 42 in turn is connected to the differential transfer sprocket 29. As previously stated, the differential transfer sprocket 29 is mounted to the differential rounds carrier 28 which is journaled for rotation along bearing means 70 and 72 The gear 42 is coupled to a gear 43 which is mounted to a first side of the upper transfer wheel 20. A second side of the upper transfer wheel 20 has a gear 44 associated with it. The gear 44 is coupled to a gear 45. The gear 45 also is connected to the input sprocket 19 and is mechanically coupled to a magazine drive motor 76. The magazine drive motor 76 drives the gear 45, and consequently, the input sprocket 19, at a speed corresponding to the speed at which the rounds 63 leave the magazine 3.
It should be noted that the gears 40 and 41 and the gears 43 and 44 for example, may be formed in the hub structure 26 of the transfer wheels and need not be manufactured separately and attached individually to the transfer wheels. It also may be observed that because the lower housing portion 18 is rotatable about the bearing means 32 and because the output sprocket 31 is attached to the housing portion 18, gun turret 10 movement appears as a weapon demand rate signal to the reservoir 1. That is, rotation of the housing portion 18 in response to weapon 7 movement in the azimuth plane 9 causes the gear 37 to move with the housing portion 18, affecting the remaining gears in the same way as if the weapon 7 were firing ammunition rounds 63.
The function of the differential rounds carrier 28 while not complex, is probably the most difficult to understand. FIG. 3a is a functional flow schematic illustrating the situation where input ammunition flow is equal to output demand. In this situation, the input sprocket 19 is rotating at the output sprocket 31 speed. Consequently, there is no translation of the differential rounds carrier 28 or the transfer sprocket 29. The sprocket 29 of the differential rounds carrier 28 rotates about its axis consistent with the firing rate, but it acts as if its axis were fixed in space.
FIG. 3b illustrates the situation where weapon 7 demand is greater than flow. It is evident that the transfer sprocket 29 of the differential rounds carrier 28 must move to the right taking rounds from the upper transfer wheel 20 at a higher rate than they are being fed in, thereby depleting both the upper transfer wheel 20 and the lower transfer wheel 30. In the instance where flow is greater than demand, the opposite action occurs. That is, the differential rounds carrier 28 and the sprocket 29 move to the left, filling the upper and lower transfer wheels 20 and 30 respectively.
FIG. 3c illustrates the situation where flow from the magazine 3 is equal to weapon 7 demand but the turret 10 is moving clockwise or to the left in the diagrammatic illustration shown. Turret 10 motion in the azimuth plane 9 effects a response similar to that for a demand rate situation. The transfer sprocket 29 location moves relatively to the output sprocket 31 because the output sprocket 31 is fixed to the moving structure of lower housing portion 18. Because the output sprocket 31 moves with the turret 10, the conveyance means 14 is not required to twist to accommodate azimuth motion. Azimuth movement of the turret 10 may be viewed as the output sprocket 31 moving to meet the rounds 63 in the transfer wheels 20 and 30. Therefore, for a fixed output rate, the lower transfer wheel 30 rotation generated by turret 10 rotation causes the differential rounds carrier 28 and transfer sprocket 29 to increase the number of rounds 63 in the upper transfer wheel 20.
When the turret moves to the right, the opposite condition occurs, that is the output sprocket 31 is moving away from the rounds 63. To accommodate this apparent increase in demand, the differential rounds carrier 28 moves to the right and the transfer sprocket 29 places additional rounds in the lower transfer wheel 30. Movement of rounds 63 between the upper and lower transfer wheels 20 and 30 rounds is possible because dead space is provided in each transfer wheel for this contingency. That is, not all positions available for storage of the rounds 63 in the transfer wheels 20 and 30 are utilized in the normal operating range of the reservoir 1. Those additional spaces are available to accommodate the rounds transfer between the wheels 20 and 30 during azimuth plane 9 movement of the turret 10.
Those skilled in the art will recognize that the position of the differential rounds carrier 28 may be monitored and controlled by instrumentation not shown, affecting the drive assembly for the weapons system 2. In the event the reservoir provided by the upper and lower transfer wheels tends to overfill, the drive motor 76 for the magazine may be shut down until the transfer wheel compliment is reduced to a prescribed level. On the other hand, if the demand from the weapon 7 exceeds the flow capacity of the magazine, the reservoir provided by the transfer wheels would empty and the weapon can be shut down until the input flow partially fills the transfer wheels. In the embodiment illustrated, the total rotation of the differential rounds carrier 28 is limited to 267.degree.. This limit is set by the input and output sprockets and the scoop cam 64. That is, the sprocket 29 of the differential rounds carrier can not pass by the input sprocket 19 or the output sprocket 31.
Additional electrical or mechanical stops or combinations of them may be utilized, if desired.
The operational description of the reservoir 1 made in conjunction with FIG. 3 is shown as a combination in FIG. 5 and the components of the reservoir 1 are equated in the two diagrammatic views. As previously mentioned, power to the reservoir 1 is derived from two sources, a weapon drive motor 75 and the magazine drive motor 76. Hence, the reservoir 1 acts as the balancing media. Driving torque is transmitted to the reservoir 1 via flexible shafts 77. In order to operate the shafts at high r.p.m. and low torque, a pair of drive gear boxes 78 is incorporated in the system. Low torque and flexible shafts are synonomous with smaller shafts, tighter bend radii and low wind up. The two drive gear boxes 78 are identical and are arranged in a 1 to 10 step down ratio. The ratio is achieved in a single double lead worm gear mesh. The flexible shaft input is utilized to drive the rounds 63 from the magazine 3 and to drive the gear 45. As indicated, the same drive is applied, via the gear 45, to the input sprocket 19. A similar arrangement is used between the weapons 7 drive system, the conveyance means 14 and the gear 37 on the turret 10 side of the reservoir 1.
Storage for the ammunition rounds 63 is provided by the magazine 3. Preferably, the magazine 3 is the drum type. Conventionally, this type of magazine has a fixed outer drum which incorporates a single helical track. The magazine motor 76, located at the drum, powers the inner drum whose drive staves push the rounds along the outer drum helix, out of the magazine and into the closed loop conveyance means 4 which runs between the magazine 3 and the stationary housing part 17 of the reservoir 1, located above the turret 10. Rounds are next transferred from the conveyance means 4 into the upper transfer wheel 20 of the reservoir 1 which is powered at the same rate by the magazine drive motor via the gear 45, gear 44 arrangement.
Round transfer proceeds to the lower transfer wheel 30 of the reservoir 1 and then into a closed loop conveyance means 14 running between the bottom of the reservoir 1 and the weapon 7. The weapon drive motor 75 provides weapon and feeder action as well as driving the lower portion of the reservoir 1.
The mechanical differential principle of the reservoir 1 automatically provides for major compensation between gun demand and magazine 3 feed rate during weapon firing, acceleration and shut down. The differential rounds carrier 28 senses the transient deviations between the rotation speed of the upper transfer wheel 20 of the reservoir 1 as established by feed speed of the magazine 3 and the speed of the lower transfer wheel 30 as determined by firing rate demand. The differential rounds carrier 28 seeks an azimuthal position proportional to the upper and lower transfer wheel speed difference and transfers rounds from the upper transfer wheel 20 to the lower transfer wheel 30 and hence to the weapon 7 at the proportional speed point. In effect, the reservoir 1 compliment of rounds is depleted or added to as required to accommodate firing start up or termination.
The relatively large reservoir 1 capacity provided by the upper and lower transfer wheels minimizes magazine loop control requirements. A simple control loop employing sensing switches in the reservoir 1 may be utilized to provide a trimming and safety control function. For example, those skilled in the art will recognize that control loops are known which will shut down and restart the magazine drive motor 76 in the event that the reservoir 1 capacity or depletion limits are reached, as when caused by magazine or conveyor loop failure, for example.
The reservoir 1, in addition to providing both a means of reducing system power and one plane conveyor chute motion, localizes system damage in the event of either a weapon 7 or magazine 3 jam. Should either weapon or magazine malfunction, the differential rounds carrier 28 in the reservoir 1 will be driven out of its normal operating zone, as may be sensed by potentiometer limits, for example, and will shut down either the gun drive 75 or the magazine drive 76. An additional full or empty limit sensor may be used to sense any additional travel of the differential rounds carrier 28 which can be programmed to shut off all power to the system 2. In the event of a double failure, mechanical stops may be utilized to halt differential round carrier movement.
Numerous variations, within the scope of the appended claims, will be apparent to those skilled in the art in light of the foregoing description and accompanying drawings. For example, the silhouette of the reservoir 1 may be varied in other embodiments of this invention. As indicated, the lower housing portion 18 may have a combined function of forming a portion of a gun turret enclosure. Likewise, while it is advantageous to attach the reservoir 1 to the gun turret 10, many of the desirable features of the invention may be obtained even where the reservoir 1 is positioned remote from the weapon 7 or its associated gun turret 10. The reservoir 1 may be mounted adjacent the magazine, for example. Similarly, while the weapon system 2 was described as utilizing a movable rapid fire weapon and weapon mount, either or both may be fixed. The ability to match input with output rates for a weapon system occurs even with a fixed weapon installation. The rounds 63 may be linked or linkless ammunition of various calibers. The diameter of the transfer wheels may vary in other embodiments of this invention. In like manner, the design of the feed and transfer sprockets may be changed. These variations are merely illustrative.