Patent Publication Number: US-2022228831-A1

Title: Accessory mount for machine gun spade grip

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a continuation-in-part application claiming the benefit of U.S. patent application Ser. No. 17/468,626, filed on Sep. 7, 2021, which claims the benefit of U.S. Provisional Application Ser. No. 63/074,505, filed on Sep. 4, 2020, the entireties of both applications are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     This disclosure relates to implementations of an accessory mount that can be attached to the spade grip of a machine gun. 
     BACKGROUND 
     Machine guns mounted to vehicles and tripods are usually equipped with spade grips, instead of buttstocks. A typical spade grip includes twin handles disposed on opposite sides of, and adjacent to, a thumb pad trigger mechanism so that a user&#39;s thumb(s) will naturally rest against the thumb pad trigger mechanism when grasping one or both handles. 
     Modern firearms, including machine guns, are routinely equipped with flashlights, infrared and visible laser sights, and other electrically powered accessories. These weapon-mounted electrical accessories are often used in conjunction with remote switches, also referred to as control devices, for convenience. However, machine guns equipped with a spade grip lack an ergonomic position to mechanically attach one or more control devices in close proximity to the thumb pad trigger mechanism. 
     Accordingly, it can be seen that needs exist for the accessory mount for a machine gun spade grip disclosed herein. It is to the provision of an accessory mount for a machine gun spade grip configured to address these needs, and others, that the present invention is primarily directed. 
     SUMMARY OF THE INVENTION 
     Implementations of an accessory mount for a machine gun spade grip are provided. In general, a spade grip includes twin handles that are disposed on opposite sides of, and adjacent to, a thumb pad trigger mechanism for a firearm, a machine gun in particular. The accessory mount is attached to the upper arm of the spade grip, adjacent one of the twin handles. One or more control devices, used to operate weapon-mounted electrical accessories, can be attached to the accessory mount. 
     An example accessory mount for a firearm spade grip comprises:
         a bridge member having a top and a bottom, the top of the bridge member includes a mounting interface and the bottom of the bridge member includes a cutout adapted to receive a portion of the firearm spade grip therein;   a clamp member removably attached to the bottom of the bridge member;   an actuator arm having a base and a distal end, the base of the actuator arm is attached to the top of the bridge member; and   a paddle actuator rotatably connected to the distal end of the actuator arm.       

     Another example accessory mount for a firearm spade grip comprises:
         a bridge member having a top and a bottom, the top of the bridge member includes three mounting interfaces and the bottom of the bridge member includes a cutout adapted to receive a portion of the firearm spade grip therein;   a clamp member removably attached to the bottom of the bridge member;   an actuator arm having a base and a distal end, the base of the actuator arm is attached to one of the three mounting interfaces on the top of the bridge member; and   a paddle actuator rotatably connected to the distal end of the actuator arm.       

     Yet another example accessory mount for a firearm spade grip comprises:
         a bridge member having a top and a bottom, the top of the bridge member includes a mounting interface and the bottom of the bridge member includes a cutout adapted to receive a portion of the firearm spade grip therein;   a clamp member removably attached to the bottom of the bridge member;   an actuator arm having a base and a distal end, the base of the actuator arm is attached to the top of the bridge member;   a paddle actuator rotatably connected to the distal end of the actuator arm;   a control device configured to operate at least one weapon-mounted electrical accessory, the control device is attached to the mounting interface on the top of the bridge member; and   a cross-bolt safety axially displaceable between an active position, whereby rotational movement of the paddle actuator is prevented, and an inactive position.       

    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates an example accessory mount according to the principles of the present disclosure, wherein the accessory mount is secured to the spade grip of a machine gun and the paddle actuator is shown flipped back. 
         FIG. 2  illustrates the accessory mount shown in  FIG. 1 , wherein the paddle actuator has been flipped forward. 
         FIG. 3  illustrates the accessory mount shown in  FIG. 1 , wherein the control devices have been removed. 
         FIG. 4  illustrates the accessory mount shown in  FIG. 3  removed from the machine gun spade grip. 
         FIG. 5  illustrates an exploded view of the accessory mount shown in  FIG. 4 . 
         FIGS. 6 and 7  illustrate another configuration of the example accessory mount shown in  FIG. 4 . 
         FIGS. 8 and 9  illustrate yet another configuration of the example accessory mount shown in  FIG. 4 . 
         FIG. 10  illustrates another example accessory mount according to the principles of the present disclosure, wherein the accessory mount is secured to the spade grip of a machine gun and the paddle actuator is shown flipped back. 
         FIG. 11  illustrates the accessory mount shown in  FIG. 10 , wherein control devices have been attached to the accessory adapters. 
         FIG. 12  illustrates the accessory mount shown in  FIG. 11 , wherein the paddle actuator has been flipped forward. 
         FIG. 13  illustrates the accessory mount shown in  FIG. 10  removed from the machine gun spade grip. 
         FIG. 14  illustrates an exploded view of the accessory mount shown in  FIG. 13 . 
         FIGS. 15 and 16  illustrate isometric views of the actuator arm shown in  FIG. 14 . 
     
    
    
     Like reference numerals refer to corresponding parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION 
       FIGS. 1-3  illustrate an example accessory mount  100  secured to the spade grip  102  of a machine gun. Though only a partial cutaway of the spade grip  102  is shown in  FIGS. 1-3 , in general, an example spade grip  102  includes twin handles  104  that are disposed on opposite sides of, and adjacent to, a thumb pad trigger mechanism  106  for a firearm, a machine gun in particular. The accessory mount  100  is attached to the upper arm  108  of the spade grip  102 , adjacent a handle  104  thereof. One or more control devices (also referred to as “remote switches”)  116 , used to operate weapon-mounted electrical accessories, can be attached to the accessory mount  100 . An example control device  116  is the Hot Button, sold by Unity Tactical, LLC, shown in the illustrations. Each example control device  116  includes a pushbutton switch  118  and a flexible cable having a connector or plug. The flexible cable is not illustrated for the sake of clarity. 
     As shown best in  FIGS. 3-5 , an accessory mount  100  includes a bridge member  120  that can be secured to the upper arm  108  of a spade grip  102  by a moveable clamp member  122 . The bottom of the bridge  120  includes a cutout  124  adapted to receive a portion of the spade grip arm  108  therein. The clamp member  122  is secured to the bottom of the bridge member  120  by threaded fasteners  126 . Each threaded fastener  126  extends through an opening  128  in the clamp member  122  to engage a threaded hole (not shown) in the bottom of the bridge member  120 . Tightening the threaded fasteners  126  brings the bridge member  120  and the clamp member  122  together, thereby securing the accessory mount  100  to the upper arm  108  of the spade grip  102  (see, e.g.,  FIG. 1 ). 
     As shown best in  FIG. 5 , the top of the bridge member  120  includes three mounting interfaces  130 . Though, in some implementations, the bridge member  120  may only include one or two mounting interfaces  130 . Each mounting interface  130  is a recessed channel in the top of the bridge member  120  configured to receive a portion of an accessory adapter  132 , or other compatible component, therein. 
     Each accessory adapter  132  is configured to be attached to a mounting interface  130  on the top of the bridge member  120 . The base  134  of each accessory adapter  132  is configured to fit within the recessed channel of a mounting interface  130 . Although, in some implementations, only a portion of the base  134  is configured to fit within the recessed channel of a mounting interface  130 . Threaded fasteners  136  are used to attach each accessory adapter  132  to a mounting interface  130  of the accessory mount  100 . Each threaded fastener  136  extends through an opening  138  in the bridge member  120  to engage a threaded hole in the proximal end  138  of an accessory adapter  132 . The top side of an accessory adapter  132  includes an accessory mounting interface  140  (e.g., a MIL-STD-1913 accessory mounting rail) adapted for the attachment of a control device  116  (see, e.g.,  FIGS. 1 and 2 ). 
     As shown in  FIGS. 3-5 , in some implementations, the accessory mount  100  may include a paddle actuator  142  that is connected to the bridge member  120  by an actuator arm  144 . The actuator arm  144  extends up from the bridge member  120  to position the paddle actuator  142  above the attached control devices  116 . The paddle actuator  142  can be used to simultaneously actuate the pushbutton switch  118  of both control devices  116  attached to the accessory mount  100 . Also, in conjunction with a lockout pin  158 , the paddle actuator  142  can be fixed in position over the pushbutton switches  118  of attached control devices  116 . In this way, the paddle actuator  142  is used to prevent actuation of the control devices  116 . 
     As shown in  FIG. 5 , two axially spaced contact protuberances  150  extend from the bottom face of the paddle actuator  142 . In some implementations, as shown in  FIG. 5 , each contact protuberance  150  is formed in an approximately hemispherical shape. Two knuckles  164 ,  166  extend from a side of the paddle actuator  142 . The first knuckle  164  includes an opening  160  that extends therethrough and the second knuckle  166  includes a threaded hole  162 . 
     The paddle actuator  142  is moveable between a first position (shown in  FIG. 1 ) and a second position (shown in  FIG. 2 ). The paddle actuator  142  rotates about the shaft  148  of a fastener  146  used to secure it to the distal end of the actuator arm  144 . The fastener  146  extends through the opening  160  in the first knuckle  164  of the paddle actuator  142 , through an opening  154  in the distal end of the actuator arm  144 , and engages with the threaded hole  162  in the second knuckle  166  of the paddle actuator  142 . 
     As shown best in  FIGS. 4 and 5 , the base  152  of the actuator arm  144  is configured to fit within the recessed channel of a mounting interface  130  located on the bridge member  130 . In the preferred implementation, the base  152  of the actuator arm  144  is attached to the middle mounting interface  130 . Threaded fasteners  156  are used to attach the base  152  of the actuator arm  144  to the mounting interface  130  of the bridge member  120 . Each threaded fastener  156  extends through an opening  138  in the bridge member  120  to engage a threaded hole in the base  152  of the actuator arm  144 . 
     In some implementations, spring-loaded detent assemblies are employed to positively position (or removably latch) the paddle actuator  142  in the first position (shown in  FIG. 1 ) and the second position (shown in  FIG. 2 ). Each spring-loaded detent assembly (not shown) is nested in a bore  182  found in each side of the actuator arm  144 , near its distal end. Only one bore  182  is shown in the illustrations. Each spring-loaded detent assembly operates in conjunction with a detent locking groove  184  located on the interior side of each knuckle  164 ,  166  of the paddle actuator  142 . The outer end of each spring-loaded detent assembly includes a detent ball that extends slightly out of its bore  182 . This configuration, then, allows the detent ball to engage with the detent locking groove  184  when the paddle actuator  142  is rotated into the first position or the second position. 
     As shown best in  FIG. 5 , the accessory mount  100  may include a lockout pin  158 , the purpose of which will be described below. The lockout pin  158  includes a cylindrical shaft having a chamfered tip  176 , and a pull ring  178  attached to one end. The lockout pin  158  also includes a spring-loaded detent assembly  180  positioned near the chamfered tip  176 . 
     As shown in  FIG. 1 , when the paddle actuator  142  is flipped back, the paddle actuator  142  does not cover, or otherwise inhibit, use of either control device  116  attached to the accessory mount  100 . 
     As shown in  FIG. 2 , when the paddle actuator  142  is flipped forward, the paddle actuator  142  is positioned over both control devices  116  attached to the accessory mount  100 . Further, each contact protuberance  150  is positioned over the pushbutton switch  118  of an underlying control device  116 . Applying downward pressure to the top face  168  of the paddle actuator  142  presses the contact protuberances  150  into their respective pushbutton switches  118 , thereby actuating both control devices  116  simultaneously. 
     Although not shown, the paddle actuator  142  can be fixed in the flipped forward position using the lockout pin  158 . To do so, the pin openings  170 ,  172  extending through the paddle actuator  142  are aligned with a groove  174  in the distal end of the actuator arm  144 . The lockout pin  158  is then pushed through this alignment of openings ( 170 ,  172 ,  174 ), thereby fixing the paddle actuator  142  in position over the control devices  116 . In this way, the paddle actuator  142  is used to cover, and prevent the use of, the underlying control devices  116 . 
     As shown in  FIGS. 1-4 , when the lockout pin  158  is not being used, it can be stored within an opening  186  extending through the middle section of the actuator arm  144 . The spring-loaded detent assembly  180  prevents the lockout pin  158  from inadvertently falling out. 
     As shown in  FIGS. 6 and 7 , in some implementations, an accessory mount  100  may be assembled and used without a paddle actuator  142 , the actuator arm  144 , or a lockout pin  158 . Such a configuration of the accessory mount  100  includes the bridge member  120 , the moveable clamp member  122 , and two accessory adapters  132 . 
     As shown in  FIGS. 8 and 9 , in some implementations, an accessory mount  100  may be assembled and used with only a single accessory adaptor  132 . Such a configuration of the accessory mount  100  includes the bridge member  120 , the moveable clamp member  122 , and a single accessory adapter  132  attached to the center mounting interface  130  of the bridge member  120 . 
       FIGS. 10-12  illustrate another example accessory mount  200  secured to the spade grip  102  of a machine gun. The spade grip  102  includes twin handles  104  that are disposed on opposite sides of, and adjacent to, a thumb pad trigger mechanism  106  for a firearm, a machine gun in particular. The accessory mount  200  is similar to the accessory mount  100  discussed above, but the paddle actuator  242  and the actuator arm  244  have been modified to incorporate a cross-bolt safety  290  that replaces the lockout pin  158 . 
     The paddle actuator  242  rotates about the shank  248  of a pivot pin  246  coupling it to the distal end of the actuator arm  244 . The pivot pin  246  is positioned within a bore defined by openings  260 ,  262  in the knuckles  264 ,  266  of the paddle actuator  242 , and an opening  254  in the distal end of the actuator arm  244 . The openings ( 254 ,  260 ,  262 ) defining the bore are axially aligned. A retaining pin  292 , positioned within another opening  267  in one knuckle  266  of the paddle actuator  242 , holds the pivot pin  246  in position. The retaining pin  292  includes a threaded head  292   a  and an elongate shaft  292   b.  The threaded head  292   a  is used to secure the retaining pin  292  within the opening  267  in the paddle actuator  242 . The elongate shaft  292   b  of the retaining pin  292  extends across a circumferential groove  249  in the shank  248  of the pivot pin  246 . In this way, lateral displacement of the pivot pin  246  is prevented. The elongate shaft  292   b  in the illustrated embodiment is cylindrical and has a circular cross-section, although other non-circular cross-sectional shapes are possible (e.g., square). 
     As shown best in  FIGS. 14 and 15 , the actuator arm  244  includes a groove  274 ,  276  in a front side and a back side of the distal end. The forward-facing groove  274  is positioned to be in axial alignment with an aperture  270 ,  272  in each knuckle  264 ,  266  of the paddle actuator  242  when the paddle actuator  242  is in the flipped forward position; the rearward facing groove  276  is positioned to be in axial alignment with the aperture  270 ,  272  in each knuckle  264 ,  266  of the paddle actuator  242  when the paddle actuator  242  is in the flipped back position. Each groove  274 ,  276  defines a curved surface configured to receive therein, at least a portion of, the first end portion  290   a  of the cross-bolt safety  290 . 
     As shown best in  FIG. 14 , the cross-bolt safety  290  is an elongate rod having two end portions  290   a,    290   b  separated by a circumferential groove  296 . One end portion  290   a  includes a clearance cutout  294  and the other end portion  290   b  includes two detent recesses  298   a,    298   b.  The cross-bolt safety  290  is axially displaceable between an active position, whereby rotational movement of the paddle actuator  242  is prevented, and an inactive position. In this way, the cross-bolt safety  290  can be used to fix the paddle actuator  242  in either a flipped back position (see, e.g.,  FIG. 11 ) or a flipped forward position (see, e.g.,  FIG. 12 ). The cross-bolt safety  290  is secured within a bore defined by the aperture  270  in one knuckle  264  that is axially aligned with the aperture  272  in the other knuckle  266  of the paddle actuator  242 . The first end portion  290   a  of the cross-bolt safety  290  partially projects from one aperture  272  in the inactive position and the second end portion  290   b  partially projects from the opposing aperture  270  in the active position. In either the inactive or active positions, the cross-bolt safety  290  is readily displaced by pressure from a user&#39;s finger on a projecting end portion  290   a,    290   b.  The retaining pin  292  described above is used to limit lateral movement of the cross-bolt safety  290 . In the illustrated embodiment, the elongate shaft  292   b  of the retaining pin  292  extends across the clearance cutout  294  in the first end portion  290   a  of the cross-bolt safety  290 . The width of the clearance cutout  294  is greater than the diameter of the retaining pin shaft  292   b.  In this way, the cross-bolt safety  290  is able to laterally move between the inactive position and active position. The detent recesses  298   a,    298   b  of the cross-bolt safety  290  are axially spaced. 
     A spring-loaded detent assembly is employed to positively position the cross-bolt safety  290  in both the inactive and active positions, acting as a force-to-overcome mechanism. The spring-loaded detent assembly also provides tactile resistance to any axial displacement of the cross-bolt safety  290 . The spring-loaded detent assembly is carried in a bore  278  in one knuckle  264  of the paddle actuator  242 . The spring-loaded detent assembly comprises a spring  280 , a ball detent  282 , and a set screw  284  that retains the spring  280  and ball detent  282  within the bore  278  of the paddle actuator  242 . The ball detent  282  is resiliently biased, by the spring  280 , for projection into one detent recess  298   a  when the cross-bolt safety  290  is in the inactive position and for projection into the other detent recess  298   b  when the cross-bolt safety  290  is in the active position. 
     Operation and use of the Cross-Bolt Safety 
     The cross-bolt safety  290  can be used to lock the paddle actuator in either the flipped forward position (see, e.g.,  FIG. 12 ) or the flipped back position (see, e.g.,  FIG. 11 ). Axially displacing (i.e., laterally sliding) the cross-bolt safety  290  to the active position when the paddle actuator  242  is in the flipped forward position or the flipped back position places the first end portion  290   a  of the cross-bolt safety  290  in the forward-facing groove  274  or the rearward facing groove  276 , respectively. In this way, the paddle actuator  242  is prevented from rotating, thereby locking it in position. 
     The paddle actuator  242  can be unlocked by axially displacing (i.e., laterally sliding) the cross-bolt safety  290  to the inactive position. This removes the first end portion  290   a  from the groove ( 274  or  276 ) in the front side or back side of the actuator arm  244  and positions the circumferential groove  296  of the cross-bolt safety  290  over the same groove ( 274  or  276 ). The circumferential groove  296  of the cross-bolt safety  290  is sized so that it&#39;s too small to engage with the curved surface of either groove  274 ,  276 . In this way, the paddle actuator  242  can be rotated between the flipped forward position and the flipped back position. 
     While a Hot Button control device  116  is shown throughout the illustrations, it is to be understood that other control devices (i.e., remote switches) capable of being attached to one of the accessory mounts  100 ,  200  disclosed herein may be used. 
     The bridge  120 , the clamp member  122 , the accessory adapters  132 , the paddle actuators  142 ,  242 , and the actuator arms  144 ,  244  are fabricated of an aluminum alloy, but could be fabricated of another suitably durable and light weight material (e.g., a stainless-steel alloy). 
     Although not shown, it is contemplated that an accessory adapter  132  having an integrated control device  116  could be developed and used in conjunction with either accessory mount  100 ,  200  disclosed herein. 
     Reference throughout this specification to “an embodiment” or “implementation” or words of similar import means that a particular described feature, structure, or characteristic is included in at least one embodiment of the present invention. Thus, the phrase “in some implementations” or a phrase of similar import in various places throughout this specification does not necessarily refer to the same embodiment. 
     Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. 
     The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the above description, numerous specific details are provided for a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that embodiments of the invention can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations may not be shown or described in detail. 
     While operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results.