Patent Publication Number: US-2023140580-A1

Title: Loading mechanism for suspended loop ammunition

Description:
FIELD OF THE DISCLOSURE 
     The present disclosure relates to ammunition magazines in which linked rounds of ammunition are stowed in suspended loops each depending from an uppermost round supported by a pair of laterally spaced rails near the top of the magazine. 
     BACKGROUND OF THE INVENTION 
     Overhead ammunition magazines within armored vehicles for carrying linked ammunition are typically very difficult to load by hand. An operator must create a loop by hand and then guide the loop onto an overhead support rail near the top of the magazine, often in a blind fashion and/or while lifting considerable weight. An experienced operator typically supports some of the weight of the source belt of linked ammunition over his/her shoulder while the other hand is used to lift the loop and slide the ammunition into place. Operator error is frequent, the loading operation is difficult on the operator&#39;s fingers, and the lifted weight often exceeds the  95 th percentile overhead lifting limit for human factors. 
     SUMMARY OF THE DISCLOSURE 
     A mechanism for loading suspended loops of linked ammunition onto rails of an ammunition magazine may generally comprise a guideway, a carriage guided by the guideway, and an anti-backdrive device. 
     The guideway may include inner cam surfaces and outer cam slots each extending vertically from a lower portion of the guideway and curving near an upper portion of the guideway toward a loading end of the magazine. The carriage may include a support block slidably received by the guideway and a tandem bucket mounted on the support block by a linkage. The tandem bucket may include a pair of cradles for respectively receiving two adjacent ammunition rounds, and inner and outer followers respectively engaging the cam surfaces and cam slots. The tandem bucket is maintained in a horizontal orientation and may be loaded with two adjacent rounds of a belt of linked ammunition when the carriage is at a lowered position. The carriage may then be raised manually, wherein the tandem bucket is articulated by camming engagement of the inner and outer followers to a vertical orientation to deposit one of the two rounds onto the magazine rails with the other round and trailing rounds suspended therefrom. 
     The anti-backdrive device may be configured in the manner of a one-way gate or turnstile to prevent the deposited rounds from returning with the carriage back to the lowered position. 
     The loading mechanism may be configured as a separate unit removably attachable to an ammunition magazine, or may be permanently fixed to or made integral with the ammunition magazine. 
     The loading mechanism of the present disclosure facilitates the task of loading an overhead ammunition magazine with suspended loops of linked ammunition. The loops may be created by the operator in a comfortable position and installed onto the rails of the ammunition magazine with ease, thereby reducing loading errors and operator injuries. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING VIEWS 
       The nature and mode of operation of the present invention will now be more fully described in the following detailed description taken with the accompanying drawing figures, in which: 
         FIG.  1    is a perspective view of an ammunition magazine loaded with ammunition and equipped with a loading mechanism formed in accordance with an embodiment of the present disclosure; 
         FIG.  2    is another perspective view of the ammunition magazine and loading mechanism shown in  FIG.  1   , wherein the ammunition magazine is empty of ammunition; 
         FIG.  3    is a perspective view of the loading mechanism in isolation, wherein a carriage of the loading mechanism is shown in a lowered position; 
         FIG.  4    is another perspective view of the loading mechanism in isolation, wherein the carriage of the loading mechanism is shown in the lowered position; 
         FIG.  5    is a view similar to that of  FIG.  3   , wherein the carriage is shown in a raised position; 
         FIG.  6    is a view similar to that of  FIG.  4   , wherein the carriage is shown in the raised position; 
         FIG.  7    is a perspective view of the carriage of the loading mechanism in isolation; 
         FIG.  8 A  is a cross-sectional view of the loading mechanism wherein the carriage is shown in the lowered position; 
         FIG.  8 B  is a cross-sectional view of the loading mechanism wherein the carriage is shown in the raised position; and 
         FIG.  9    is a view similar to that of  FIG.  1   , wherein the carriage of the loading mechanism is shown in its raised position depositing rounds of ammunition onto rails of the ammunition magazine. 
     
    
    
     DETAILED DESCRIPTION 
       FIGS.  1  and  2    show an ammunition magazine  1  for holding a belt of linked ammunition  2  in a serpentine arrangement of loops suspended from a pair of spaced-apart rails  3  provided at an upper portion of the ammunition magazine. As will be appreciated, each loop depends from an uppermost round of ammunition supported at opposite ends by spaced rails  3 . Ammunition magazine  1  is shown equipped with a loading mechanism  10  formed in accordance with an embodiment of the present disclosure. Loading mechanism  10  may be used by an operator to facilitate the task of loading rounds of linked ammunition  2  in magazine  1 . More specifically, loading mechanism  10  may be used by an operator to lift and create precise loops of ammunition and slide the loops onto the laterally spaced rails  3 . Loading mechanism  10  may be arranged at a loading end  4  of magazine  1  opposite a dispensing end  5  of magazine  1  from which the belt of ammunition is progressively dispensed as rounds are fired. 
     Reference is also made now to  FIGS.  3 - 6   . Loading mechanism  10  may generally comprise a guideway  12  and a carriage  14  movable along guideway  12  between a lowered position ( FIGS.  3  and  4   ) and a raised position ( FIGS.  5  and  6   ). Loading mechanism  10  may further comprise an anti-backdrive device  16  at its upper end. 
     Guideway  12  may include a pair of parallel sidewalls  20  each having an inner cam surface  22  and an outer cam slot  24 . Cam surface  22  and cam slot  24  may extend vertically from a lower portion of guideway  12  and curve near an upper portion of guideway  12  to extend horizontally a relatively short distance toward rails  3  at the loading end  4  of ammunition magazine  1 . Sidewalls  20  may be connected by a faceplate  26  which may have a pair of vertical travel slots  28 . 
     Carriage  14  may include a support block  30  slidably received between the sidewalls  20  of guideway  12 , and a handle  31  fixed to support block  30  and arranged to extend through travel slots  28  and outward from faceplate  26  for access by an operator. Support block  30  may be guided for vertical displacement by two pairs of guide rollers  32  arranged on opposite sides of support block  30  such that each pair of guide rollers  32  is received by a respective one of the cam slots  24  in sidewalls  20 . As may be understood, support block  30  is manually movable in upward and downward directions relative to guideway  12 , but is prevented from pivoting or swinging about a transverse axis by the use of two guide rollers  32  instead of one on each lateral side. Carriage  14  may further include a tandem bucket  34  configured to support two adjacent rounds of ammunition, and a linkage  36  pivotally connected to support block  30  and tandem bucket  34  to permit tandem bucket  34  to translate and pivot relative to support block  30  as described in greater detail below. Tandem bucket  34  may include a pair of inner followers  37  arranged at opposite sides thereof to respectively engage inner cam surfaces  22 , and a pair of outer followers  39  arranged at opposite sides thereof and respectively received by outer cam slots  24 . Tandem bucket  34  may include two cradles  35 A and  35 B each sized and configured to receive and support a predetermined type of ammunition round, wherein each cradle  35 A,  35 B is bifurcated by a central gap  38  through which the belt assembly linking the rounds may pass. Inner followers  37  may be associated with cradle  35 B, and outer followers  39  may be associated with cradle  35 A. 
     As best seen in  FIGS.  7 ,  8 A, and  8 B , linkage  36  of carriage  14  may include a straight link  40  having a first end pivotally coupled to support block  30  by a pivot pin  42  to enable link  40  to pivot relative to support block  30  about a laterally extending axis of pin  42 , and a second end pivotally coupled to tandem bucket  34  by a pivot pin  44  to enable tandem bucket  34  to pivot relative to link  40  about a laterally extending axis of pin  44 . Pivot pins  42  and  44  may be embodied as spring pins or cylindrical pins. When carriage  14  is moved to the lowered position shown in  FIG.  8 A , engagement of inner followers  37  with inner cam surface  22  and engagement of outer followers  39  with a boundary surface of cam slot  24  positions tandem bucket  34  and linkage  36  such that cradles  35 A and  35 B are horizontally adjacent one another. When carriage  14  is moved to the raised position shown in  FIG.  8 B , engagement of inner followers  37  with inner cam surface  22  and engagement of outer followers  39  with a boundary surface of cam slot  24  positions tandem bucket  34  and linkage  36  such that cradles  35 A and  35 B are vertically adjacent one another. 
     Anti-backdrive device  16  may include a transverse axle  50  rotatably journalled by rotational supports  51  mounted atop guideway  12  to permit the axle to rotate about its axis relative to the guideway. For example, each rotational support  51  may include a base portion  51 A and a top portion  51 B secured to the base portion by fasteners  52 , wherein base portion  51 A and top portion  51 B each include a semi-cylindrical cutout for receiving a radially reduced end portion of axle  50 . Axle  50  may carry one or more gate members  54  extending radially from the axle, each gate member having a distal end received through a corresponding slot  56  in guideway  12 . Axle  50  and each gate member  54  may rotate about the axis of axle  50  between a blocking position and a passage position with respect to a round of ammunition carried in cradle  35 A. Axle  50  may be biased by a torsion spring  58  urging the axle in a counterclockwise angular direction as viewed in  FIGS.  8 A and  8 B  toward its blocking position, and each gate member  54  may be angled to be pushed and rotated against the bias of torsion spring  58  toward its passage position when engaged by a round of ammunition in cradle  35 A as carriage  14  is moved from its lowered position to its raised position. Cradle  35 A, however, cannot pass completely under gate members  54 . Once the round of ammunition in cradle  35 A passes under gate member  54 , axle  50  and gate members  54  rotate in a reverse direction under the power of torsion spring  58 . Consequently, a round of ammunition carried in cradle  35 A will be prevented by gate members  54  from returning through anti-backdrive device  16  with carriage  14  is returned from its raised portion to its lowered position. In this manner, anti-backdrive device  16  functions as a one-way turnstile through which ammunition rounds may be received onto rails  3  at loading end  4  of magazine  1 . Of course, the function performed by anti-backdrive device  16  may be achieved by mechanisms differing from that shown in the figures and described above. 
     Loading mechanism  10  may comprise a pair of latches  18  configured for releasable mating with a pair of latch receptacles  7  provided at loading end  4  of ammunition magazine  1 , whereby loading mechanism  10  may be removably attached to magazine  1 . Other releasable fastening devices, for example threaded fasteners, may be used in place of latches. Alternatively, loading mechanism  10  may be permanently fixed to ammunition magazine  1 , or loading mechanism  10  may be incorporated as an integral non-removable feature of ammunition magazine  1  by forming inner cam surfaces  22  and outer cam slots  24  directly into an existing ammunition box structure for similar performance. 
     An operator uses loading mechanism  10  by inserting two adjacent rounds of ammunition into cradles  35 A,  35 B when carriage  14  is at its lowered position, as shown in  FIG.  1   , and then manually moving carriage  14  from its lowered position to its raised position as depicted in  FIG.  9   . When carriage  14  reaches its raised position, the round of ammunition carried by  35 A will be delivered onto support rails  3  of ammunition magazine  1 , and the round of ammunition carried by cradle  35 B, along with subsequent trailing rounds linked thereto, will be suspended from the supported round as the belt linking the rounds of ammunition passes through the lateral space between rails  3 . The process may be repeated to suspend additional loops to reload ammunition magazine  1 . 
     In the depicted embodiment, handle  31  is provided on support block  30  for manual operation. Additionally or alternatively, a cable having a pull handle may be connected to support block  30  and routed over a pulley to enable an operator to raise carriage  14  by pulling downward on the pull handle, thereby allowing the operator to use his or her body weight for advantage. 
     As may be understood, loading mechanism  10  may be scaled and dimensioned depending on the type of linked ammunition. 
     The loading mechanism of the present disclosure greatly assists an operator in the task of loading an overhead ammunition magazine with suspended loops of linked ammunition. The loops may be created by the operator in a comfortable position and installed onto the rails of the ammunition magazine with ease. Consequently, loading errors and operator injuries are reduced. 
     While the disclosure describes 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 embodiments as may be apparent to one of ordinary skill in the art.