Abstract:
The weapon interface mounting device is designed to permit a secure interface between a Mil-Std 1913 or similar rail and a compatible component such as an optical device, bipod, or light source. It can be easily installed, requires no adjustment by the user, and will mate securely to rails that are out of specification or poorly manufactured. The weapon interface mounting device utilizes a constant force system that applies adequate pressure to positively secure any accessory or device despite being subject to rough treatment such as recoil shock from a host weapon. Unlike prior art devices, the weapon interface mounting device insures repeatability by utilizing a mechanical index system.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is related to and claims priority from earlier filed U.S. Provisional Patent Application No. 61/111,285, filed Nov. 4, 2008. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to accessory mounting assemblies for combat weapons. 
     BACKGROUND OF THE INVENTION 
     As the field of combat and commercial weaponry expands, numerous add-on enhancements have become available for attachment to standard firearms. For example, the well-known M16 weapon system, includes a mil-std 1913 dovetail rail extending along the top of the upper receiver. This rail provides a convenient mounting point for many types of accessories such as tactical lights, night vision devices, laser sighting modules, reflex sights, fore grips, and bipods. 
     Field modification of weapons is critical in combat situations. As such, standardized attachment assemblies have been developed to allow quick and easy removal and mounting of accessory devices relative to the dovetail rails. Examples of such attachment assemblies are disclosed in U.S. Pat. Nos. 5,276,988 and 7,493,721. 
     Although some needs have been met with such prior art devices, significant performance issues remain. In particular, manufactured rails having even slight imperfections are not well accommodated by the prior art. They are not well secured and repeated shock due to firing can lead to degradation and eventual failure of the rail/interface system. Accordingly, a need exists for a weapon interface mounting device that performs well regardless of the quality of the rail with which it interfaces. 
     Although prior art devices posses an indexing system, accessories mounted using such devices nevertheless require adjustment due to residual slack between the rail and the indexing geometry. Clearly, a need also exists for a weapon interface mounting device that is capable of automatic indexing with 100% repeatability that requires no active adjustment by the user. 
     Prior art devices do not attempt to constrain the rail in all three orthogonal dimensions. This, together with the inherent imperfect manufacturing of such rails, are also responsible for amplification of residual slack that occurs during the firing process, thereby leading to inevitable mechanical failure. A need exists for a weapon interface mounting device that constrains the rail in all three orthogonal dimensions as well as having the capability to fully compensate for residual slack in all dimensions. 
     OBJECTS OF THE INVENTION 
     It is an objective of the present invention to provide a lever-deployed clamp-driver system for incorporation into a weapon interface mounting device that is enabled by the driver system to provide extremely rapid removable mounting of a weapon accessory onto a weapon-mounted interface rail in a manner that constrains the rail in all three orthogonal dimensions as well as having the ability to compensate for residual slack in all dimensions. 
     It is a further objective of the present invention that the lever of the driver system be made and arranged to be readily and rapidly manipulated by a user to rotationally select between (1) an open orientation enabling a disengaged mode for rapid and convenient accessory removal and replacement and (2) a closed orientation enabling an automatically locked in an engaged operational mode wherein the accessory is held, clamped solidly in place on the rail. 
     It is a further objective of the present invention to provide a weapon interface mounting device that incorporates the modular lever-activated mechanism for extremely rapid deployment and removal of accessories, that provides automatic compensation for dimensional variations and that requires no threaded adjustment manipulation and yet performs well regardless of out-of-specification deviations in the quality of the rail with which it interfaces. 
     It is an objective of the present invention to provide a weapon interface mounting device that is capable of automatic indexing with 100% repeatability. 
     SUMMARY OF THE INVENTION 
     
         
         
           
             The above objectives are met by a first main embodiment, i.e. a lever-activated clamp-driver system intended as a marketable product for attachment to and incorporation with complementary components that can be readily incorporated into clamping-type mounting systems and devices, and by a second main embodiment, i.e. a clamping-type mounting device operable for serving as an interface between a rail mounted to a weapons platform and an accessory. 
           
         
       
    
     Functionally, a mounting device in the field of the present invention can be regarded as essentially a basic C-clamp forceably engaging a workpiece, in this case the rail, between a fixed clamp jaw and a movable clamp jaw that can manipulated by the user to apply/release the clamping force. 
     The clamping driver system embodiment enables a mounting device to provide mateable engagement clamped onto the rail at a desired location along the firing axis, the direction of the path taken by a bullet. The mounting device may also be made in a version that is operable for providing repeatable indexing capability between the weapons platform and the accessory 
     As a major point of the invention, the clamping driver system includes a compressible drive component having a lever-driven side that receives compressive clamping force from a cam configured on the lever arm, pivoting about a common pivot pin within a range approximating 90 degrees, and a movable clamp jaw configured at the second and opposite driving side of the compressible drive component, made and arranged to transmit clamping force from the cam onto the proximal side edge of the rail. 
     The cam-originated displacement transmitted via the compressible drive component is designed to have sufficient stroke-length that moving the lever to initiate the disengaged mode facilitates initial attachment of a mounting device onto the rail and, when mounted with the lever locked in the engaged mode, to generate sufficient compressive clamping force with further capability to automatically compensate and take up the slack for dimensional variations in rail width, even with a rail that is poorly manufactured, e.g. with dimensions falling substantially outside specified tolerances. 
     The accessory-to-weapon clamping device embodiment of the invention can be regarded functionally and structurally as a C-clamp having two major portions: (1) a first portion constituting essentially the clamping driver system embodiment, with the movable clamp-jaw engaging the proximal side edge of the rail, and (2) a second portion having a first end operationally combined with the first portion, a mid-region serving as main clamp body providing an accessory-mounting platform and extending across above the rail to a fixed clamp-jaw portion that engages the rail. 
     In basic form, the mounting device of the second embodiment provides the capability for a lever activated continuous positional adjustment and clamped setting anywhere along the rail. 
     To the extent that this clamping capability maintains positive interlock integrity for at least two out of three possible orthogonal dimensions along with substantial interlock integrity for the third dimension, the lever activated automatically-compensated clamping capability of the basic mounting device acts to take up the slack for a poorly manufactured rail and provides support in maintaining positional integrity and helps the indexing process in absorbing the recoil shock during firing. 
     In an optional variation of the second embodiment of the invention, the mounting device may be made to include enhanced capability of indexing by the further incorporation of an articulate finger that engages adjacent crosswise indexing slots of the MIL-STD-1913 or similar rail. An expansion feature of the articulate finger takes up slack to compensate for dimensional variations including tolerances in the indexing slots of the manufactured rail, facilitating the indexing process and ensuring positional integrity in accommodating recoil during firing. 
     DESCRIPTION 
     The term “firing axis”, as used herein, is used to define the longitudinal axis of a firearm as shown in  FIG. 1 . Its positive direction is collinear with that taken by a bullet as shown in the figure. It is denoted the “x axis” in  FIGS. 4-9 . 
     The term “orthogonal to the firing axis”, as used herein, is used to define the plane orthogonal to the firing axis as defined by a right-handed coordinate system. It is the “yz” plane as denoted in  FIGS. 4-9 . 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       FIG.  1 —weapon interface mounting device functioning as an interface between a firearm and mounted accessory. 
       FIGS.  1 A- 1 E—Five views of the claimed clamping driver system.embodiment. 
       FIGS.  1 F- 1 H—Three views of the claimed weapon interface mounting device embodiment, shown clamped onto a weapon-mounted rail. 
       FIG.  2 —First perspective view of the weapon interface mounting device. 
       FIG.  3 —Alternate perspective view of the weapon interface mounting device. 
       FIG.  4 —Top ( 4 A) and end-on ( 4 B) views of the weapon interface mounting device. 
       FIG.  5 —Edge view ( 5 A) and cross section ( 5 B) along the line A-A′. 
       FIG.  6 —Cross section showing driver in open ( 6 A) and closed ( 6 B) positions. 
         FIGS. 6C ,  6 D—Cross-sections showing the clamping driver system in the closed-lever clamped operational mode and in the open-lever released mode. 
       FIG.  7 —Detailed view of the assembled ( 7 A) and unassembled ( 7 B) driver. 
       FIG.  8 —Alternate views of a standard rail along the three orthogonal axes. 
       FIG.  9 —Views detailing the mating surfaces between the weapon interface mounting device and a standard rail. 
     
    
    
     BRIEF DESCRIPTION OF THE ITEMS SHOWN IN THE FIGURES 
     
         
           1 —firearm 
           2 —accessory 
           9 —auxiliary indexing component 
           10 —weapon interface mounting device a.k.a. clamp embodiment 
           11 —clamp body, forming channel 
           12  accessory-mounting surface 
           13 —primary indexing component 
           14 —compressible edge configuration of  13  a.k.a. articulated finger 
           15 —compressible drive subassembly 
           16 —driver system a.k.a. driver embodiment 
           17 —shaped surface of fixed clamp jaw 
           18 —shaped surface of movable clamp-jaw  71   
           19 —lever 
           19 A—pivot point of lever 
           19 B—cam portion of lever 
           20 —safety a.k.a bar, lock, latch 
           30 —rail such as the MIL STD-1913 
           31 —ridges on rail for indexing 
           32 —rail cross-section 
           33 —slots on rail for indexing 
           34 —beveled edges a.k.a. angled rail-edge facet 
           60 —driver housing 
           71 —movable clamp-jaw driven from compressible drive component  73  a.k.a. driver component proximate rail side a.k.a. second spring-end retainer 
           71 A—offset extension portion of  71   
           72 —rail-mating angled facet surface on  71 A 
           73 —compressible drive component variable resistance member 
           74 —lever-driven component driving compressible drive component  73  a.k.a. driver component proximate lever side .a.k.a. first spring-end retainer part 
       
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 1  shows a firearm ( 1 ) with an accessory ( 2 ) mounted thereto. The mounting apparatus consists of a MIL-STD 1913 rail ( 30 ) and the weapon interface mounting device ( 10 ) of the present invention. As shown in  FIG. 8 , the MIL-STD-1913 rail ( 30 ) comprises a series of ridges ( 31 ) interspersed with flat slots ( 33 ). Accessories are mounted by means of a “rail-grabber” which is clamped to the slots ( 33 ) or onto the rail ( 30 ) itself. 
     Driver system  16 , shown in five orthogonal views in  FIGS. 1A-E , constitutes, in a basic form of the invention, a first of two main embodiments. Driver system  16  enables user-manipulation of lever  19  to deploy an automatically-locked operational mode wherein a cam portion  19 B of lever  19  transmits compressive clamping force onto a special compressible drive subassembly  15 , partially enclosed in driver housing  60  and including a movable clamp-jaw  71 , configured with a shaped surface  18  ( FIG. 1C ) for engaging and clamping a workpiece in co-operation with an external fixed clamp-jaw that is not included in this first main embodiment. 
     Driver system  16  is configured with a pair of mounting flanges including two holes  12 A for bolted attachment to some form of host complementary clamping structure that includes a fixed clamp jaw, thus enabling the creation of clamping devices that can be adapted and directed to various clamping requirements including particularly but not limited to a weapon interface mounting device 
     Optionally, in a particular version of driver system  16  that is specifically intended for incorporation into a weapon interface mounting device utilizing a MIL STD-1913 rail  30  or equivalent, the shaped surface  18  ( FIG. 1C ) is specially configured as shown also in  FIGS. 1A ,  1 D,  1 E,  1 F,  5 A and  9 B, so as to interface and clamp rail  30  as the workpiece at a single angled facet rail-mating surface  72  of the offset extension portion  71 A of clamp-jaw  71 . 
     Lever  19  becomes automatically safety-locked in the operational mode shown when manipulated by a user to the orientation shown, releasable only by depressing safety-lock-bar  20 . 
       FIGS. 1F-1H  show three orthogonal views of a weapon interface mounting device  10 , which incorporates the above-described particular version of driver system  16  and constitutes the second of two main embodiments of the invention. 
       FIG. 1F  is a top/plan view of the weapon interface mounting device  10 , showing the general appearance as viewed by a user facing the firing direction and looking down onto the weapon. 
     The main clamp body  11  shown is a version with an alternative shape in place of the generally-orthogonal plan shape shown in FIGS.  1  and  2 - 6 . This alternative shape acts to increase the working area of the accessory-mounting surface  12  ( FIGS. 1F and 5A ) and the working area of interface interaction with rail  30 , otherwise the two shapes are generally equivalent. 
     A driver system  16  is attached to the main clamp body  11  as shown in the optional usual right-handed orientation, i.e. with lever  19  oriented in the firing direction as shown in  FIGS. 1 ,  2  and  3 . For left-handed orientation, since the driving housing  60  is configured with a pair of holes  12 A for symmetric bolted attachment to clamp body  11 , the driver system  16  can be readily mounted to the main clamp body  11  with the direction of lever  19  reversed 180 degrees. Similarly, for left-handed orientation in a system that utilizes primary indexing bar  13 , it is designed for convenient mounting reversal to retain recoil impact properties. 
       FIG. 1G  shows a cross-section, taken at  1 G- 1 G of  FIG. 1F , showing a main portion of rail  30 , traversed overhead by the main clamp body  11  so as to form a channel within which the rail  30  is clamped at its two opposite edges between a fixed jaw  11 A configured in main clamp body  11  and movable clamp jaw  71  having a shaped surface  18  including an offset extension portion  71 A configured with a single-facet rail-mating angled facet  72 . 
       FIG. 1H  depicts a bottom view of rail  30  clamped in place in between channel walls  11 A and  11 B of main clamp body  11 , with the components of the driver system  16  extending through the d river housing  60  and a portion of clamp body  11  such that offset drive extension  72  extends into the channel region as shown to engage the right hand edge  18  of rail  30  as in  FIG. 1G  . . . . 
     An optional variation of the weapon interface mounting device  10  further includes an indexing feature shown in and described in connection with  FIGS. 2-5 . 
     The second main embodiment of this invention, the weapon interface mounting device ( 10 ), is shown in alternate perspective views in  FIGS. 2-3 . Designed to enable a secure interface between a weapon system and accessory component, it can be modular or custom designed for a particular device. Overall details of the device are shown in  FIGS. 4-7 . Details of the geometry involved in the interfacing between the device and the rail ( 30 ) are indicated in  FIG. 9 . 
     The weapon interface mounting device ( 10 ) of the present invention accomplishes the following:
         1. constrains the rail in all three orthogonal dimensions,   2. compensates for residual slack in each respective dimension, thereby enabling it to:
           perform well regardless of the quality of the rail with which it interfaces,   act as a “shock absorber” against the recoil of firing, and   
           3. provides automatic indexing with 100% repeatability.       

     It accomplishes the above goals by utilizing the following design principles:
         a. employing geometrical features mateable to the external dimensions of a Mil-Std 1913 or similar rail ( 30 ),   b. exploiting the compliant properties of spring material in the compressible drive component  73 , and in the compressible edge  14  of optional primary indexing component  13 , to automatically compensate for any residual space between the mating surfaces ( 9 ,  13 ,  14 ,  31 , and  15 ,  17 ,  18 ,  34 ) of the weapon interface mounting device ( 10 ) and the rail ( 30 ) as well as providing shock absorbance against the recoil of firing, and   c. providing simple geometry ( 9 ,  13 ) operable for securing both sides of a rail ridge ( 31 ).       

     As seen in  FIG. 4 , the second main embodiment of the weapon interface mounting device ( 10 ) is shown utilizing a version of driver housing that is substantially rectangular in the XY plane, having a channel ( 11 ) to accommodate a MIL-STD-1913 or similar rail ( 30 ). The primary ( 13 ) and auxiliary ( 9 ) indexing components fit into adjacent crosswise slots ( 33 ) scored at regular intervals along the length of the rail ( 30 ) shown in  FIGS. 8A and 9A . An articulated finger ( 14 ) acts as a spring to push against the edge of the ridge ( 31 ) flanking a slot ( 33 ) in order to accommodate any residual slack. The details of this mated geometry are shown in  FIG. 9A . Not only is a tight fit enabled, but when positioned correctly, helps to offset the recoil shock of a fired weapon that would otherwise loosen the interfaced connection. In addition, the indexing system facilitates 100% repeatability with respect to the positioning of the accessory device on the weapons system. 
     The edges of the channel ( 11 ) provides shaped surfaces ( 17 ,  18 ) that are mateable to the outer beveled edges ( 34 ) of the rail ( 30 ) shown in  FIG. 8C . The details of this fit are indicated in  FIGS. 8C and 9B . The driver system ( 15 ) is actuated by means of a lever ( 19 )  19  as shown in  FIG. 6A-6D . The lever  19  locks automatically in the engaged mode by a safety-lock push-bar  20  to prevent unintended release.  FIG. 6A  shows lever  19  in a released orientation close to the clockwise end of its rotational range. Lever  19  remains unlocked at this orientation since it is holding safety-lock push-bar  20  in a depressed orientation.  FIG. 6B  shows lever  19  having been rotated clockwise to its operational orientation, locked by safety-lock push-bar  20 . When properly deployed, the driver system  15  forces a snug engagement between the shaped surface of the channel ( 17 ,  18 ) and the beveled edges ( 34 ) of the rail ( 30 ) as detailed in  FIG. 9B . 
     A preferred embodiment of the compressible drive subassembly  15 , utilized in both the driver system  16  embodiment and in the clamping device  10  embodiment, is shown in  FIG. 7A . The compressible drive subassembly  15  includes a rail-side component, i.e. movable clap jaw ( 71 ) and a lever-side component ( 74 ) with a compressible drive component implemented as four coil springs  73 , therebetween.  FIG. 7B  shows drive subassembly  15  of  FIG. 7A  with the lever-side component  74  removed to show the uncompressed extent of coil springs  73 .  FIG. 7C  is a top view of lever-side component  74  ( FIG. 7A ). 
       FIG. 6C  is a cross-section taken at axis  6 C- 6 C of  FIG. 1G , showing a clamping device embodiment incorporating a compressible drive subassembly  15 . Lever  19  is shown locked in its engaged mode by safety lock push-bar  20 . Part of the rail side component  71  is configured with a surface  18 , ( FIG. 1G ) on offset extension ( 71 A) that is mateable to the beveled edges ( 34 ) of a rail ( 30 ). This is actuated by a cam portion  19 B of the lever ( 19 ) being pressed against the lever side component ( 74 ) which, by way of the springs ( 73 ), urges the rail side component ( 71 ) and its mateable surface on offset extension ( 71 A) against an angled facet  72  of the beveled edges ( 34 ) of the rail ( 30 ) as well as the shaped surface opposite the driving member ( 17 ) as shown in  FIG. 9B . Because the rail ( 30 ) cross section ( 32 ) and the mating surfaces ( 17 ,  18 ) are angled in the YZ plane, a component of force is applied in both the Y and Z direction, thereby tightly securing the rail ( 30 ) in the YZ plane. Compressible drive component  73 , as implemented by the springs or similar equivalent, takes up any slack due to poor manufacturing, recoil, or other effects. 
       FIG. 6D  shows the clamping device of  FIG. 6  having been released from clamped engagement with the rail edge  34  by a user urging lever  19  clockwise while depressing the safety lock push-bar  20 . With lever  19  having been rotated to the clockwise end of its approximately 90 degree rotational range as shown, further rotation is blocked by the end of safety lock push-bar  20 . The lever-side driver. component  74  has been displaced from its locked location shown in  FIG. 6C , by a stroke length that is determined by the shape of cam  19 B on lever  19 . This moves the movable jaw, i.e. offset extension  71 A of rail-side component, i.e. movable clamp-jaw  71 , clear of the rail edge  34  to allow adjustment or removal from the rail. 
     The stroke length of rail-side component  71  and its offset extension  72  is less than that of driver-side component  74  by the amount of differential engaged/disengaged compression in the coil springs forming the compressible drive component  73 . Rail clearance in the disengaged mode is ensured by a pair of relatively small weak retaining coil springs located toward the far side and thus not visible in this view, recessed and arranged to apply compressive bias force between a lower region of the main clamp body  11  and the rail-side driver component  71 , sufficient to ensure required rail clearance in the disengaged mode. 
     The foregoing descriptions regarding the structure and operation of the driver device are equally applicable to both the first and second main embodiments as claimed. 
     In this manner, weapon interface mounting device enables a secure interface between a Mil-Std 1913 or similar rail and a compatible component such as an optical device, bipod, or light source. It can be easily installed with the assurance of positioning repeatability, requires no adjustment by the user, and mates securely to rails that are out of specification or poorly manufactured despite the imparted and consistent shock due to recoil of a fired weapon.