Patent Description:
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's fingers, and the lifted weight often exceeds the 95th percentile overhead lifting limit for human factors. <CIT> discloses ammunition containers that are reloadable from within an armored vehicle to supply a remote weapon system mounted externally to the vehicle. <CIT> discloses an ammunition magazine for stowing belted rounds for rapid fire guns. The magazine has generally horizontal laterally-spaced side rails for slidably supporting the rounds. <CIT> discloses methods and means for loading ammunition containers for the guns or cannon of military aircraft.

According to the present invention, a loading mechanism for loading a belt of linked ammunition into a magazine having a pair of spaced-apart rails is provided as defined in independent claim <NUM>. Furthermore, as defined in independent claim <NUM>, the present invention concerns a method of loading a belt of linked ammunition into a magazine having a pair of spaced-apart rails.

The inventive loading mechanism comprises 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.

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> and <FIG> show an ammunition magazine <NUM> for holding a belt of linked ammunition <NUM> in a serpentine arrangement of loops suspended from a pair of spaced-apart rails <NUM> 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 <NUM>. Ammunition magazine <NUM> is shown equipped with a loading mechanism <NUM> formed in accordance with an embodiment of the present disclosure. Loading mechanism <NUM> may be used by an operator to facilitate the task of loading rounds of linked ammunition <NUM> in magazine <NUM>. More specifically, loading mechanism <NUM> may be used by an operator to lift and create precise loops of ammunition and slide the loops onto the laterally spaced rails <NUM>. Loading mechanism <NUM> may be arranged at a loading end <NUM> of magazine <NUM> opposite a dispensing end <NUM> of magazine <NUM> from which the belt of ammunition is progressively dispensed as rounds are fired.

Reference is also made now to <FIG>. Loading mechanism <NUM> may generally comprise a guideway <NUM> and a carriage <NUM> movable along guideway <NUM> between a lowered position (<FIG> and <FIG>) and a raised position (<FIG> and <FIG>). Loading mechanism <NUM> may further comprise an anti-backdrive device <NUM> at its upper end.

Guideway <NUM> may include a pair of parallel sidewalls <NUM> each having an inner cam surface <NUM> and an outer cam slot <NUM>. Cam surface <NUM> and cam slot <NUM> may extend vertically from a lower portion of guideway <NUM> and curve near an upper portion of guideway <NUM> to extend horizontally a relatively short distance toward rails <NUM> at the loading end <NUM> of ammunition magazine <NUM>. Sidewalls <NUM> may be connected by a faceplate <NUM> which may have a pair of vertical travel slots <NUM>.

Carriage <NUM> may include a support block <NUM> slidably received between the sidewalls <NUM> of guideway <NUM>, and a handle <NUM> fixed to support block <NUM> and arranged to extend through travel slots <NUM> and outward from faceplate <NUM> for access by an operator. Support block <NUM> may be guided for vertical displacement by two pairs of guide rollers <NUM> arranged on opposite sides of support block <NUM> such that each pair of guide rollers <NUM> is received by a respective one of the cam slots <NUM> in sidewalls <NUM>. As may be understood, support block <NUM> is manually movable in upward and downward directions relative to guideway <NUM>, but is prevented from pivoting or swinging about a transverse axis by the use of two guide rollers <NUM> instead of one on each lateral side. Carriage <NUM> may further include a tandem bucket <NUM> configured to support two adjacent rounds of ammunition, and a linkage <NUM> pivotally connected to support block <NUM> and tandem bucket <NUM> to permit tandem bucket <NUM> to translate and pivot relative to support block <NUM> as described in greater detail below. Tandem bucket <NUM> may include a pair of inner followers <NUM> arranged at opposite sides thereof to respectively engage inner cam surfaces <NUM>, and a pair of outer followers <NUM> arranged at opposite sides thereof and respectively received by outer cam slots <NUM>. Tandem bucket <NUM> may include two cradles 35A and 35B each sized and configured to receive and support a predetermined type of ammunition round, wherein each cradle 35A, 35B is bifurcated by a central gap <NUM> through which the belt assembly linking the rounds may pass. Inner followers <NUM> may be associated with cradle 35B, and outer followers <NUM> may be associated with cradle 35A.

As best seen in <FIG>, <FIG>, linkage <NUM> of carriage <NUM> may include a straight link <NUM> having a first end pivotally coupled to support block <NUM> by a pivot pin <NUM> to enable link <NUM> to pivot relative to support block <NUM> about a laterally extending axis of pin <NUM>, and a second end pivotally coupled to tandem bucket <NUM> by a pivot pin <NUM> to enable tandem bucket <NUM> to pivot relative to link <NUM> about a laterally extending axis of pin <NUM>. Pivot pins <NUM> and <NUM> may be embodied as spring pins or cylindrical pins. When carriage <NUM> is moved to the lowered position shown in <FIG>, engagement of inner followers <NUM> with inner cam surface <NUM> and engagement of outer followers <NUM> with a boundary surface of cam slot <NUM> positions tandem bucket <NUM> and linkage <NUM> such that cradles 35A and 35B are horizontally adjacent one another. When carriage <NUM> is moved to the raised position shown in <FIG>, engagement of inner followers <NUM> with inner cam surface <NUM> and engagement of outer followers <NUM> with a boundary surface of cam slot <NUM> positions tandem bucket <NUM> and linkage <NUM> such that cradles 35A and 35B are vertically adjacent one another.

Anti-backdrive device <NUM> may include a transverse axle <NUM> rotatably journalled by rotational supports <NUM> mounted atop guideway <NUM> to permit the axle to rotate about its axis relative to the guideway. For example, each rotational support <NUM> may include a base portion 51A and a top portion 51B secured to the base portion by fasteners <NUM>, wherein base portion 51A and top portion 51B each include a semicylindrical cutout for receiving a radially reduced end portion of axle <NUM>. Axle <NUM> may carry one or more gate members <NUM> extending radially from the axle, each gate member having a distal end received through a corresponding slot <NUM> in guideway <NUM>. Axle <NUM> and each gate member <NUM> may rotate about the axis of axle <NUM> between a blocking position and a passage position with respect to a round of ammunition carried in cradle 35A. Axle <NUM> may be biased by a torsion spring <NUM> urging the axle in a counterclockwise angular direction as viewed in <FIG> toward its blocking position, and each gate member <NUM> may be angled to be pushed and rotated against the bias of torsion spring <NUM> toward its passage position when engaged by a round of ammunition in cradle 35A as carriage <NUM> is moved from its lowered position to its raised position. Cradle 35A, however, cannot pass completely under gate members <NUM>. Once the round of ammunition in cradle 35A passes under gate member <NUM>, axle <NUM> and gate members <NUM> rotate in a reverse direction under the power of torsion spring <NUM>. Consequently, a round of ammunition carried in cradle 35A will be prevented by gate members <NUM> from returning through anti-backdrive device <NUM> with carriage <NUM> is returned from its raised portion to its lowered position. In this manner, anti-backdrive device <NUM> functions as a one-way turnstile through which ammunition rounds may be received onto rails <NUM> at loading end <NUM> of magazine <NUM>. Of course, the function performed by anti-backdrive device <NUM> may be achieved by mechanisms differing from that shown in the figures and described above.

Loading mechanism <NUM> may comprise a pair of latches <NUM> configured for releasable mating with a pair of latch receptacles <NUM> provided at loading end <NUM> of ammunition magazine <NUM>, whereby loading mechanism <NUM> may be removably attached to magazine <NUM>. Other releasable fastening devices, for example threaded fasteners, may be used in place of latches. Alternatively, loading mechanism <NUM> may be permanently fixed to ammunition magazine <NUM>, or loading mechanism <NUM> may be incorporated as an integral non-removable feature of ammunition magazine <NUM> by forming inner cam surfaces <NUM> and outer cam slots <NUM> directly into an existing ammunition box structure for similar performance.

An operator uses loading mechanism <NUM> by inserting two adjacent rounds of ammunition into cradles 35A, 35B when carriage <NUM> is at its lowered position, as shown in <FIG>, and then manually moving carriage <NUM> from its lowered position to its raised position as depicted in <FIG>. When carriage <NUM> reaches its raised position, the round of ammunition carried by 35A will be delivered onto support rails <NUM> of ammunition magazine <NUM>, and the round of ammunition carried by cradle 35B, 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 <NUM>. The process may be repeated to suspend additional loops to reload ammunition magazine <NUM>.

In the depicted embodiment, handle <NUM> is provided on support block <NUM> for manual operation. Additionally or alternatively, a cable having a pull handle may be connected to support block <NUM> and routed over a pulley to enable an operator to raise carriage <NUM> 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 <NUM> 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.

Claim 1:
A loading mechanism (<NUM>) for loading a belt of linked ammunition (<NUM>) into a magazine (<NUM>) having a pair of spaced-apart rails (<NUM>), the loading mechanism (<NUM>) comprising:
a guideway (<NUM>); and
a carriage movable along the guideway (<NUM>) between a lowered position and a raised position, the carriage (<NUM>) including an articulated tandem bucket (<NUM>) having a pair of cradles (35A,35B) arranged to support two adjacent rounds of the belt of linked ammunition (<NUM>);
wherein the tandem bucket (<NUM>) is engaged by the guideway (<NUM>) such that the pair of cradles (35A,35B) are in a horizontal orientation when the carriage (<NUM>) is in the lowered position and the pair of cradles (35A,35B) are in a vertical orientation when the carriage (<NUM>) is in the raised position, and the loading mechanism (<NUM>), further comprises an anti-backdrive device (<NUM>) arranged to prevent the two adjacent rounds from returning with the carriage (<NUM>) from the raised position back to the lowered position.