Abstract:
An RWS is configurable to adjust the height of a rotational elevation axis thereof by providing interchangeable pairs of removably mounted yoke arms, wherein the pairs have different heights. The RWS is provided with at least one fixed hanging ammunition container that is reloadable under the armored protection of the vehicle and the RWS shell.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to the field of remote-controlled weapon stations or systems (RWSs), and more particularly to vehicle-mounted RWSs designed to mount over a hatch opening in a top deck of a vehicle. 
     BACKGROUND OF THE INVENTION 
     Vehicle-mounted RWSs are retrofittable to various types of military vehicles, including but not limited to armored combat vehicles (ACVs), mine-resistant ambush protected (MRAP) vehicles, armored multi-purpose vehicles (AMPVs), amphibious assault vehicles (AAVs), and light armored vehicles (LAVs). The RWS allows personnel to operate externally-mounted weapons from the within the armored protection of the vehicle. 
     An RWS may be outfitted with selected weapons (e.g. guns and missile launchers), and non-lethal operating units (e.g. target sighting units, acoustic hailers, and illuminators), to provide desired performance capabilities. Missile launchers suitable for use in an RWS include, without limitation, a Hellfire missile launcher, a Javelin missile launcher, and a TOW missile launcher. Automatic guns that process linked ammunition are favored in RWS configurations. Some of the guns falling into this category are the MK44 chain gun, CTAI 30 mm and 40 mm canons, the M242 chain gun, the M230LF autocannon, the M2 machine gun, the M3 submachine gun, the MK19 automatic grenade launcher, the M240 machine gun, the M249 light machine gun, and the M134 machine gun. Of course, an RWS may be outfitted with weapons and operating units other than those specifically mentioned above. 
     The linked ammunition typically comes in the form of a long ammunition belt held within an ammunition container. The belt extends out through an exit opening in the container to an ammunition feed mechanism at the gun. As an existing ammunition belt advances and is used up during firing, a leading link of a subsequent ammunition belt may be coupled to a trailing link of the existing belt to accomplish reloading. In some systems, the new belt is loaded into the existing container, while in other systems, the existing emptied container is removed and replaced with a new container holding the new belt. 
     One type of ammunition container designed to be reloaded when emptied is a hanging ammunition or suspended ammunition container. In this known arrangement, an ammunition belt is folded in serpentine fashion within the ammunition container, with upper links in the belt being supported by parallel rails at or near the top of the container so as to suspend or hang folded vertical segments of the belt in the container. This type of “hanging ammo” arrangement is described, for example, in U.S. Pat. No. 2,573,774 (Sandberg); U.S. Pat. No. 4,433,609 (Darnall); and U.S. Pat. No. 8,763,511 (Schvartz et al.). 
     In designing an RWS, it is desirable to provide personnel with the capability to reload the externally mounted automatic guns with linked ammunition while the personnel remain within the relatively safe confines of the armored vehicle. U.S. Patent Application Publication No. 2012/0186423 (Chachamian et al.) describes a system for protected reloading of an RWS. The system comprises an extendable and retractable support bracket having a top plate attached to the RWS and a bottom plate for receiving and supporting an ammunition container. The bottom plate is connected to the top plate by four gas pistons enabling the bottom plate carrying the ammunition box to be raised up into the RWS turret for regular use and lowered down into the vehicle compartment for reloading. While the system enables reloading under armored protection, it requires a mechanically complicated bracket and uses space within the vehicle compartment to accommodate the lowered ammunition container during reloading. Given that the vehicle compartment is already very confined, this solution is not optimal. 
     Another system for under armor reloading of ammunition is described in the aforementioned U.S. Pat. No. 8,763,511 (Schvartz et al.). The ammunition containers disclosed by Schvartz et al. are open at the front end and the rear end such that multiple containers may be stowed end-to-end in the RWS with their belts linked for regular use. An elevator mechanism is provided to lift ammunition containers from the vehicle compartment through a hatch and into the RWS. When a rearmost container is emptied, it is removed manually or using the elevator to make room for another container. Here again, the system enables reloading under armored protection, but it requires an elevator mechanism and uses valuable space within the vehicle compartment. The system also dedicates limited space within the RWS pedestal for multiple ammunition cans associated with only a single weapon. 
     With respect to weapons configuration, RWS design has been limited by a “point solution” mindset. In other words, RWSs are predominantly designed with a specific weapon configuration in mind. This mindset is understandable, given that the RWS must incorporate sophisticated motion drive and stabilization systems to rotate the RWS turret or pedestal about an azimuth axis, and to rotate a mounted weapon about an elevation axis, with precision and accuracy. By focusing on one or perhaps a few weapon configurations, RWS designers can limit the loading variables that must be accommodated and can optimize the weapon support and motion drive systems. However, this “point solution” mindset may be detrimental to combat preparedness because an RWS having a fixed weapon configuration may become ill-suited for combat as battle conditions change. 
     The height of the RWS elevation axis is an example of an RWS design parameter that limits the available weapon configurations. A relatively low elevation axis is useful for shorter barrel guns and gives the armored vehicle a desirably low profile. However, an RWS with a relatively low elevation axis cannot accommodate certain longer barrel guns and missile launchers. U.S. Pat. No. 7,669,513 (Niv et al.) teaches an RWS intended to have a variety of weapon configurations. The RWS has an automated vertically-adjustable linkage on which a weapon mount is carried for adjusting the height of the weapon elevation axis. This type of system introduces other costs, complexities, and possible malfunction points to the RWS. 
     What is needed is an RWS that enables reloading of ammunition under armor without using valuable space within the vehicle compartment and without relying on a conveyor mechanism. 
     What is also needed is a mechanically simple RWS that can be readily outfitted with a variety of weapon configurations depending upon changing combat requirements. 
     SUMMARY OF THE INVENTION 
     In an embodiment of the present invention, an RWS is configurable to adjust the height of a rotational elevation axis thereof by providing interchangeable pairs of removably mounted yoke arms, wherein the pairs have different heights. 
     The configurable RWS apparatus comprises a pedestal adapted to be mounted on an armored vehicle for rotation relative to the armored vehicle about an azimuth axis. The pedestal includes a pair of laterally-spaced yoke arm attachment interfaces. The RWS apparatus also comprises a first pair of elevation yoke arms and a second pair of elevation yoke arms selectively exchangeable with the first pair of elevation yoke arms in being removably mounted on the pedestal. The yoke arms are configured for removable mounting on the pair of yoke arm attachment interfaces of the pedestal for movement with the pedestal. A pair of elevation rotary bearings are respectively supported by the mounted pair of elevation yoke arms in alignment with one another to define the elevation axis. The RWS apparatus further comprises an elevation drive motor, and an elevation drive hub connected to the elevation drive motor and supported by one of the pair of elevation rotary bearings, wherein the elevation drive hub is rotatable about the elevation axis by operation of the elevation drive motor. An elevation follower hub is supported by the other of the pair of rotary bearings. The elevation drive hub and the elevation follower hub are configured for removable mounting of a primary weapon thereto such that the primary weapon resides between the mounted pair of elevation yoke arms and is rotatable about the elevation axis by operation of the elevation drive motor. 
     When the first pair of elevation yoke arms are mounted on the pedestal, they support the pair of elevation rotary bearings such that the elevation axis is at a first height above the pedestal. When the second pair of elevation yoke arms are mounted on the pedestal, they support the pair of elevation rotary bearings such that the elevation axis is at a second height above the pedestal different from the first height. Consequently, the elevation axis is height-adjustable for replacing a mounted primary weapon with a different primary weapon. 
     In another embodiment of the invention, an RWS is provided with at least one fixed hanging ammunition container that is reloadable under the armored protection of the vehicle and the RWS shell. The ammunition container has an ammunition storage portion and an ammunition exit chute leading from the storage portion, and the ammunition container is fixed to the pedestal such that the storage portion of the ammunition container resides at least mostly within, preferably completely within, an interior compartment defined by the pedestal. The exit chute of the ammunition container extends through the pedestal. A belt of linked ammunition suspended in the storage portion of the ammunition container is fed through the exit chute to supply a weapon carried by the external weapon support yoke. The fixed ammunition container is reloadable by personnel under protection of the armored vehicle and the pedestal. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The nature and mode of operation of the present invention will now be more fully described in the following detailed description of the invention taken with the accompanying drawing figures, in which: 
         FIG. 1  is a perspective view of an RWS formed in accordance with an embodiment of the present invention, without any weapons or operational units installed thereon; 
         FIG. 2  is another perspective view of the RWS shown in  FIG. 1 , wherein the RWS is shown equipped with a central weapon cradle; 
         FIG. 3  is a further perspective view of the RWS shown in  FIG. 1 , viewing from underneath the RWS; 
         FIG. 4  is an exploded perspective view of the RWS shown in  FIG. 1 ; 
         FIG. 5  is a perspective view of the RWS shown in  FIG. 1 , wherein a first pair of elevation yoke arms of the RWS has been replaced with a second, taller pair of yoke arms, and the RWS is shown equipped with a lateral weapon cradle; 
         FIG. 6  is another perspective view of the RWS shown in  FIG. 5 ; 
         FIG. 7  is an exploded perspective view of an elevation yoke arm of the RWS shown in  FIG. 5 ; 
         FIGS. 8-10  depict examples of various weapon configurations of the RWS as shown in  FIG. 1 , wherein shorter yoke arms are installed; 
         FIGS. 11-14  depict examples of various weapon configurations of the RWS as shown in  FIG. 5 , wherein taller yoke arms are installed; 
         FIG. 15  is a perspective view looking upward toward an inner compartment of the RWS pedestal, wherein a base plate of the pedestal and other structure are hidden to more clearly show ammunition containers of the RWS; 
         FIG. 16  is another perspective view looking upward toward an inner compartment of the RWS pedestal, wherein a slip ring of the RWS is hidden to more clearly show ammunition containers of the RWS; 
         FIG. 17  is a perspective view of an empty ammunition container of the RWS; and 
         FIG. 18  is a cross-sectional view of the ammunition container shown in  FIG. 17 , wherein the ammunition container is loaded with an ammunition belt. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1-4  depict a remote weapon station (RWS)  10  formed in accordance with an embodiment of the present invention, wherein RWS  10  is shown without any weapons, weapon cradles, or other operational units mounted thereon. RWS  10  generally comprises a base or pedestal  12  and a weapon support yoke  14  definable by a first pair of elevation yoke arms  14 A,  14 B. As will be understood by those skilled in the art, pedestal  12  is adapted to be mounted on an armored vehicle (not shown) so as to cover a hatch opening in a top deck of the armored vehicle and be rotatable relative to the armored vehicle about an azimuth axis AZ. For this purpose, pedestal  12  may include a base plate  16  to which an outer rotary bearing race  18  is attached, and a corresponding inner rotary bearing race  20  mountable to the armored vehicle. For example, inner race  20  may be bolted onto the top deck of the armored vehicle. Pedestal  12  further includes an armored shell  22  coupled to base plate  16 . As seen in  FIG. 3 , pedestal  12  defines an interior compartment  24  that is accessible from within the armored vehicle. Shell  22  may include a pair of lateral hatches  23  at opposite lateral sides of pedestal  12 , a pair of front hatches  25  at a front end of the pedestal, and/or a topside hatch  27 . 
     Rotation of pedestal  12  about azimuth axis AZ may be driven by an azimuth drive assembly  26  fixed to an interior wall of shell  22 . Azimuth drive assembly  26  includes a motor-driven output gear  28  meshing with inner gear teeth  30  of inner race  20 . Azimuth drive assembly  26  may be commanded through an operator interface and control electronics (not shown) to control the angular position of pedestal  12  about azimuth axis AZ relative to the armored vehicle. A slip ring assembly  32  provides signal transmission to and from azimuth drive assembly  26  and other electronic units in pedestal  12  across the rotational interface. 
     In accordance with an aspect of the present invention, pedestal  12  includes a pair of laterally-spaced yoke arm attachment interfaces  34  for removable mounting of elevation yoke arms  14 A,  14 B. In the illustrated embodiment, each yoke arm attachment interface  34  includes a flat surface  36  on the exterior of shell  22 , a plurality bolt holes  38  registering with bolt holes  40  on the corresponding yoke arm  14 A,  14 B, and a central opening  42  communicating with pedestal interior compartment  24 . The pair of elevation yoke arms  14 A,  14 B are removably mounted on the pair of yoke arm attachment interfaces  34  using threaded fasteners  44  extending through aligned holes  38 ,  40 . As a result, elevation yoke arms  14 A,  14 B move with pedestal  12  as the pedestal rotates about azimuth axis AZ. As shown in the depicted embodiment, topside hatch  27  may be located between the pair of yoke arm attachment interfaces  34 . RWS  10  includes a pair of elevation rotary bearings  46 A,  46 B respectively supported by elevation yoke arms  14 A,  14 B. Elevation rotary bearings  46 A,  46 B are aligned with each other to define a rotational elevation axis EL at a first height H 1  above pedestal  12 . 
     Reference is also made now to  FIGS. 5-7 . Apparatus for RWS  10  comprises a second pair of elevation yoke arms  14 C,  14 D configured for removable mounting on the pair of yoke arm attachment interfaces  34  of pedestal  12  for movement with the pedestal. The second pair of elevation yoke arms  14 C,  14 D are taller than the first pair of yoke arms  14 A,  14 B and can be selectively swapped with the first pair of elevation yoke arms  14 A,  14 B to support the pair of elevation rotary bearings  46 A,  46 B at a second height H 2  above the pedestal greater than the first height H 1 . In this manner, elevation axis EL is height-adjustable for replacing a mounted primary weapon with a different primary weapon. 
     As may be understood from  FIGS. 4 and 7 , RWS  10  additionally comprises an elevation drive motor  48  and an elevation drive hub  50  connected to the elevation drive motor  48  and supported by elevation rotary bearing  46 A, wherein elevation drive hub  50  is rotatable about elevation axis EL by operation of elevation drive motor  48 . Elevation drive motor  48  may be housed within the elevation yoke arm that houses drive hub  50  to keep drive motor  48  near drive hub  50  and reduce complexity of a connecting drive train assembly, however drive motor  48  may be located outside of the yoke arm without straying from the invention. 
     RWS  10  also comprises an elevation follower hub  52  supported by elevation rotary bearing  46 B. Elevation drive hub  50  and elevation follower hub  52  are configured for removable mounting of at least one primary weapon thereto such that the primary weapon resides between the mounted pair of elevation yoke arms  14 A,  14 B or  14 C,  14 D and is rotatable about elevation axis EL by operation elevation drive motor  48 . For example, hubs  50  and  52  may each include a bolt hole array used to removably mount a weapon cradle  56  (shown in  FIG. 2 ) or to directly mount a primary weapon housing thereto. Weapon cradle  56  may be designed to support more than one weapon. 
     RWS  10  may further comprise a lateral hub  58  connected to elevation drive motor  48 , wherein the lateral hub  58  is rotatable about elevation axis EL by operation of elevation drive motor  48 . Lateral hub  58  is configured for removable mounting of a secondary weapon thereto, either directly or through a secondary or lateral weapon cradle  60 , such that the mounted secondary weapon is rotatable about elevation axis EL by operation of the elevation drive motor  48 . 
     Referring again to  FIG. 4 , RWS  10  may also comprise a sighting hub  62  and a corresponding sighting drive motor  64 . In the embodiment shown, sighting hub  62  is supported by the same yoke arm (either  14  B or  14 D) as elevation follower hub  52  for rotation about elevation axis EL. Sighting hub  62  is configured for removable mounting of a sighting unit thereto. Sighting hub  62  is rotatable about elevation axis EL by operation of sighting drive motor  64 . Sighting drive motor  64  is operable independently of elevation drive motor  48 , whereby sighting hub  62  and a mounted sighting unit are rotatable about the elevation axis EL independently of elevation drive hub  50  and any equipment or weapons mounted to drive hub  50 . 
     Attention is now directed to  FIGS. 4 and 7 . In an aspect of the present invention, the second pair of elevation yoke arms  14 C,  14 D may be structurally similar to the first pair of elevation yoke arms  14 A,  14 B. When mounted to pedestal  12 , each yoke arm  14 A- 14 D includes a respective base  66 S or  66 T and a respective cap  68  removably attachable onto base  66 . In the embodiment shown by the figures, the yoke arm bases  66 T (tall) of the second pair of elevation yoke arms  14 C,  14 D are taller than the yoke arm bases  66 S (short) of the first pair of elevation yoke arms  14 A,  14 B. Each base  66 S or  66 T is adapted for removable mounting to one of the yoke arm attachment interfaces  34  of pedestal  12 . For example, each yoke arm base  66 S or  66 T may include bolt holes  40  registering with the bolt holes  38  of an associated yoke arm attachment interface  34 . Caps  68  for yoke arms  14 C,  14 D may be identical to caps  68  for yoke arms  14 A,  14 B, or at least they may fit onto yoke arms  14 A,  14 B. Thus, the overall apparatus may require only a single pair of caps  68  for installation on the two bases  66  of the particular pair of yoke arms that currently mounted on pedestal  12  at a given time; the yoke arm bases  66 S or  66 T not in use at a given time do not require caps  68 . 
     When RWS  10  is configured with taller yoke arms  14 C,  14 D, the overall height of the armored vehicle may prevent it from passing through locations where there are overhead obstructions. In order to temporarily lower the overall profile height of the armored vehicle, pedestal  12  may further include a pair of yoke arm pivot interfaces  70  spaced from the pair of yoke arm attachment interfaces  34 , and the yoke arm bases  66 T of the second pair of yoke arms  14 C,  14 D may include a pivot coupling  72  configured to mate with a corresponding pivot interface  70  of pedestal  12 . For example, pivot interfaces  70  may have a pair of aligned circular pivot apertures  74  with which another pair of pivot apertures  76  in base  66 T may be aligned, and a pair of pivot covers  78  securable into the aligned pivot apertures  74 ,  76 . As a result, the second pair of yoke arms  14 C,  14 D may be pivoted relative to pedestal  12  when they are situated on, but not fixed to, yoke arm attachment interfaces  34 . In this way, the armored vehicle can be provided with a lower profile for travel. The yoke arm pivot interfaces  70  may define a yoke arm pivot axis PA parallel to and behind elevation axis EL. 
     Changeover between the first pair of yoke arms  14 A,  14 B and the second pair of yoke arms  14 C,  14 D may be carried out by unbolting yoke arm caps  68  from the mounted yoke arm bases, removing the assembled bearings, hubs, and any drive motors housed by the mounted yoke arms, and unbolting the mounted yoke arm bases  66  from yoke arm attachment interfaces  34 . The yoke arm bases  66  of the other pair of yoke arms are then bolted to the yoke arm attachment interfaces  34 , the drive assemblies are reinstalled and aligned in the newly mounted yoke arm bases  66 , and the caps  68  are bolted onto the newly mounted yoke arm bases  66 . Transferring the same drive assemblies and bearings between the short and tall yoke arms avoids hardware cost and reduces the amount of additional hardware that must be stocked. It is also contemplated to provide dedicated drive assemblies within each yoke arm  14 A- 14 D so that removal and replacement of the drive assemblies is not necessary. As will be appreciated, changeover may be accomplished quickly by trained mechanics at a military base, whereby the same armored vehicle may have one RWS configuration one day and a different RWS configuration the next. 
       FIGS. 8-10  illustrate various examples of weapon configurations of RWS  10  when the shorter pair of yoke arms  14 A,  14 B is installed on pedestal  12 . 
     In  FIG. 8 , there is central weapon cradle  56  mounted between drive hub  50  and follower hub  52 , and an M134 machine gun  100  mounted on central weapon cradle  56  as a primary weapon. A non-lethal equipment cradle  61  is coupled to lateral hub  58  and carries an acoustic hailer  102 , an illuminator  104 , and a grenade launcher  106 . A sighting unit  108  is mounted on the opposite side of the RWS to sighting hub  62 . 
     The configuration shown in  FIG. 9  includes central weapon cradle  56  mounted between drive hub  50  and follower hub  52  to support an MK19 automatic grenade launcher  110  and an M2 machine gun  112 . A javelin mount  114  is attached to lateral hub  58  and supports a javelin missile launcher  116 . Sighting unit  108  is mounted on sighting hub  62 . 
     In  FIG. 10 , a TOW missile launcher  118  has a hub bracket for direct mounting to drive hub  50  and follower hub  52 . Lateral cradle  60  supports an M240 machine gun  120 . Sighting unit  108  is mounted on sighting hub  62 . 
       FIGS. 11-14  show examples of other weapon configurations of RWS  10  when the taller pair of yoke arms  14 C,  14 D is installed on pedestal  12  replacing shorter yoke arms  14 A,  14 B. 
     In  FIG. 11 , a hellfire missile launch pod  122  has a hub bracket for direct mounting to drive hub  50  and follower hub  52 . Lateral cradle  60  supports M240 machine gun  120 . Again, sighting unit  108  is mounted on sighting hub  62 . 
     The configuration of  FIG. 12  is similar to that of  FIG. 11 , except the hellfire pod is replaced by an M230LF cradle  124  coupled to hubs  50  and  52  that carries an M230LF autocannon  126 . 
     In  FIG. 13 , a pair of 30 mm ammunition boxes  128  are associated with opposite lateral sides of RWS  10 , and an MK44 chain gun assembly  130  is mounted to hubs  50  and  52  as the primary weapon. Lateral cradle  60  supports M240 machine gun  120 , and sighting unit  108  is mounted on sighting hub  62 . 
       FIG. 14  shows TOW missile launcher  118  directly mounted to hubs  50  and  52  as the primary weapon. Lateral cradle  60  supports M240 machine gun  120 , and sighting unit  108  is mounted on sighting hub  62 . 
     The configurations shown in  FIGS. 8 through 14  are intended as non-limiting examples. Of course, many other configurations involving other weapons and equipment are possible. 
     In another aspect of the present invention, RWS  10  enables reloading of ammunition under the armored protection of the vehicle and pedestal  12  without using space within the vehicle compartment and without the need for a conveyor mechanism. As best seen in  FIGS. 15-18 , RWS  10  comprises an ammunition container  80  having an ammunition storage portion  82  and an ammunition exit chute  84  leading from the storage portion  82 , wherein the ammunition container  80  is fixed to pedestal  12  such that its storage portion  82  resides completely within interior compartment  24  of pedestal  12  and its exit chute  84  extends through shell  22  of pedestal  12 . While it is preferred that storage portion  82  fit completely within interior compartment  24 , an alternative wherein storage portion  82  is mostly within interior compartment  24  is also contemplated. Storage portion  82  of ammunition container  80  has a reload opening  86  by which the ammunition container may be reloaded with ammunition. A belt  88  of linked ammunition is fed from storage portion  82  through exit chute  84  to supply a weapon carried by the weapon support yoke  14 , and the ammunition container is reloadable by onboard personnel under protection of the armored vehicle and the pedestal. 
     Ammunition container  80  may include a flange  90  on exit chute  84 , whereby the ammunition container  80  may be fixed to shell  22  of pedestal  12  by threaded fasteners engaging the flange and the pedestal. 
     The storage portion  82  of ammunition container  80  may have a pair of side walls  92  connected by a front wall  93  and a top wall  94 , wherein at least one of a bottom and a rear of storage portion  82  is open to provide the reload opening  86 . Ammunition container  80  may take the form of a “hanging ammo” container configured with an open rear and a pair of inner support ledges  96  extending from side walls  92  to receive and suspend a folded ammunition belt  88  that is slid into the container through the rear reload opening  86 . In the depicted embodiment, both the bottom and the rear of storage portion  82  are open to provide the reload opening  86 , thereby allowing greater access during reloading. As best seen in  FIG. 18 , ledges  96  may have a slight dip or trough  97  to prevent unwanted sliding or shifting of the suspended ammunition belt  88  as the vehicle travels over uneven terrain. Support ledges  96  may be omitted if they would impede the feeding of a particular size of ammunition round. 
     As will be understood from the drawing figures, weapon support yoke  14  may be configured to support two weapons and RWS may comprise two ammunition containers  80  respectively associated with the two weapons. Those skilled in the art will understand that the dimensions and specific configuration of each ammunition container  80  may vary and will depend on the specific type of ammunition being fed. 
     To allow an operator to reload either or both of the containers  80  from the same location, and to simplify location of a firing control unit  98  sensing ammunition status, the respective reload openings  86  of the two ammunition containers  80  may face a common reloading space  99  within interior compartment  24 . 
     While the invention has been described in connection with exemplary embodiments, the detailed description is not intended to limit the scope of the invention to the particular forms set forth. The invention is intended to cover such alternatives, modifications and equivalents of the described embodiment as may be included within the spirit and scope of the invention.