Patent Publication Number: US-11029131-B2

Title: Rail interface system

Description:
This application is a continuation-in-part of co-pending application Ser. No. 16/252,502 filed on Jan. 18, 2019, which claims the benefit of U.S. Provisional Application No. 62/619,530 filed Jan. 19, 2018, the disclosure of which is hereby incorporated by reference. 
    
    
     This invention relates to a rail interface system for small firearms, and in particular a rail interface system using a lever mechanism extending through a rail opening to provide the locking force that secures the accessories directly to the rail. 
     BACKGROUND OF THE INVENTION 
     Rail interface systems (“RIS”), also commonly referred to as rail accessory systems, is a generic term for a system for attaching weapon accessories to small firearms such as pistols, rifles and light machine guns. Common weapon accessories include tactical lights, laser aiming modules, forward hand grips, weapon sights and optics, and bipods. A variety of rail interface systems have been developed for military and civilian application, including Picatinny (MIL-STD-1913), KeyMod and M-Lok®. These rail interface systems are well known in the firearms industry and most weapon accessories are compatible with one or more rail interface systems. 
     The M-LOK® RIS was developed by Magpul Industries, Corp. of Austin, Tex. and protected by several patents including U.S. Pat. Nos. 8,925,236; 9,239,209; 9,239,210; 9,429,388; and 9523,554. M-LOK® is a registered trademark of Magpul Industries, Corp. The M-LOK® RIS consists of a series of elongated rail openings (“slots”) formed in the handguard, rail or other weapon component, and a specialized T-slot nut capable of only 90-degree rotation. The “quarter-turn” T-slot nuts have a “cammed” surface that allow the “T” section to engage the backside of the handguard or rail when the fastener bolts draw down on the nuts securing the attachment of the accessory. The cammed surface also allows the “T” section to disengage the backside of the handguard or rail when fasteners are loosened. 
     M-Lok is a popular rail interface system that aims to supersede the Picatinny military standard rail interface system (MIL-STD-1913). The M-Lok® rail interface system eliminates the need for weapon components, particularly handguards to be fully outfitted with “Picatinny” style rails. The M-Lok® RIS enables the user to have a slimmer, lighter, smoother and better fenestrated handguard/fore-end with accessories mounted only where needed, whereas a Picatinny handguard typically will have rail slots along its whole length resulting in a heavier and bulkier handguard with sharp edges and poorer barrel ventilation. However, the M-Lok® RIS requires the use of separate specialized fasteners. 
     SUMMARY OF INVENTION 
     The improved rail interface system of this invention uses spring tensioned “locking” shoes that extend from the accessory body into the rail opening to restrictively engage the edges of the rail openings and hold the weapon accessory against the weapon or weapon component. The locking shoes may be adapted for use with M-Lok® style rail openings without the use of specialized nuts and fasteners. The locking shoe mechanisms provide a quick and secure integrated interface connection. The locking shoe mechanism of the RIS of this invention may be integrated into the design and functionality of any particular weapon accessory or accessory mount. In an exemplary embodiment, the RIS of this invention is incorporated into a weapon light mount used with a weapon component having conventional M-Lok style rail openings. 
     The above described features and advantages, as well as others, will become more readily apparent to those of ordinary skill in the art by reference to the following detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention may take form in various system and method components and arrangement of system and method components. The drawings are only for purposes of illustrating exemplary embodiments and are not to be construed as limiting the invention. The drawings illustrate the present invention, in which: 
         FIG. 1  is a perspective view of an exemplary embodiment of the rail interface system of this invention shown using an embodiment of a rail section and a weapon light mount; 
         FIG. 2  is an exploded view of the light mount of  FIG. 1 ; 
         FIG. 3  is a top perspective view of the light mount of  FIG. 1 ; 
         FIG. 4  is a bottom perspective view of the light mount of  FIG. 1 ; 
         FIG. 5  is a side sectional view of the light mount of  FIG. 1  shown with the shoe in the locked position; 
         FIG. 6  is an exploded view of a second exemplary embodiment of the rail interface system of this invention; and 
         FIG. 7  is a side sectional view of the rail interface of  FIG. 6 . 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description of the exemplary embodiments, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is understood that other embodiments may be utilized and that logical, structural and mechanical changes may be made without departing from the spirit or scope of the invention. To avoid detail not necessary to enable those skilled in the art to practice the invention, the description may omit certain information known to those skilled in the art. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims. 
     The drawings illustrate exemplary embodiments of the improved rail interface systems (“RIS”) of this invention. The RIS of this invention consists of complimentary components and component features that interface to securely attach the weapon accessory to the weapon or weapon component. In particular, the complimentary features and components of the RIS of this invention consist of a series of interface or “rail” openings formed in the weapon or weapon component and a lever mechanism incorporated into the weapon accessory that pivots to extend through and restrictively engage the edges of the opening thereby securely affixing the weapon accessory against the weapon or weapon component. 
     The rail openings used as part of the RIS of this invention may be formed in any weapon structure or component to which an accessory may be attached, but are most commonly formed in the hand guards or receivers. Furthermore, the arrangement and location of the rail openings on the weapon or weapon component may vary depending on application and purpose. The rail openings may all be of similar or identical size. In other alternative embodiments, rail openings can have differing sizes. Furthermore, the rail openings may or may not have consistent or constant lengths (the longer dimension of an opening) or widths (the smaller dimension of an opening). As illustrated throughout this disclosure, the rail openings can be arranged in rows such that the longer dimension of each opening is aligned with the longer dimension of at least one other opening. 
     In the RIS system of this invention, a spring tensioned sliding shoe is used to engage the edges of rail openings and the inner surface of the rail section, which securely hold the accessory component to the rail section. The spring tensioned sliding shoe mechanism may be integrated into the design and functionality of any particular weapon accessory. The lever mechanisms of this invention may be incorporated directly into the design of a weapon accessory or into the design of a mount for any such accessory. The lever mechanisms may be incorporated into weapon accessories, such as Picatinny® rail sections, handle grips, lights, lasers, and sling connections. 
     Ideally, the RIS of this invention is adapted to utilize M-Lok® style rail openings (the elongated slots for M-Lok® without using M-Lok® style fasteners. The sliding shoe mechanism eliminates the need for separate M-Lok® fasteners with existing weapons and weapon components having M-Lok® style rail openings, while still providing a quick, convenient and secure integrated interface connection. In other alternative embodiments, the sliding shoe mechanisms can be modified and adapted to interface with the rail openings of any configuration or dimension as required. 
     Referring now to the drawings,  FIGS. 1-5  illustrate the RIS of this invention using an exemplary embodiment of a weapon rail panel  100  and an exemplary embodiment of mount  200  with rail interface. Generally, rail covers are commonly used to cover weapon rails and hand guards on M16/M4 style rifles and other rail systems. As shown, rail panel  100  is a simplified depiction of a section of a conventional rail section of a firearm hand guard (not shown) of the kind used on AR-15 style rifles. Mount  200  is illustrated as light/laser mount to which a weapon light or laser  10  (only partially not shown) is affixed. 
     Rail section  100  is of conventional construction and may be machined, cast, molded or extruded from any suitable metal, plastic or composite material. Rail section  100  has an elongated rail body  110  having a subtle arcuate cross section with an outer surface  112  and an inner surface  114 . Rail section  100  also has a plurality of elongated “M-Lok” style rail openings  121  (four slots are shown). Rail openings  121  are longitudinally aligned in a row formed along the longitudinal axis of rail body  110 . Ideally, rail openings  121  are configured and dimensioned to be M-Lok compliant. As shown, each rail opening  121  is defined by a peripheral edge having opposed parallel side edges  122  and rounded end edges  124 . 
     Light mount  200  is generally cast, formed or molded of a suitable metal or plastic, which is selected to provide the desired durable, texture and thermal insulating properties. Light mount  200  includes a mount body  210  that is adapted to support a conventional weapon light, a laser or similar device (not shown). The light, laser or other device is affixed to mount body  210  by fasteners that turn into threaded lateral bores in the mount body. Mount body  210  includes an integral L-shaped protrusion (“under-hook”)  214  that extends from its bottom surface  212  at one end of the mount body. Body protrusion  214  terminates in a foot  216  that extends parallel to bottom surface  212 . Body protrusion  214  is configured and dimensioned to abut against the rounded contour of side edge  122  of rail opening  121 . In addition, foot  216  is spaced from bottom surface  212  to receive side edge  122  there between. 
     Mount  200  also includes a spring tensioned “locking” shoe  220  that slides along bottom surface  212  of mount body  210  for movement between an unlocked position and a locked position. Shoe  220  is an elongated piece dimensioned to extend through rail opening  121 . Shoe  220  has a raised guide shoulder  222  that shiftably seats within a longitudinal channel  213  formed in bottom surface  212  of mount body  210 . Shoe  220  is held against bottom surface  212  by a nut  230  and bolt  232 . Bolt  232  extends through bore  231  in mount body  210  and a longitudinal slot  221  in shoe  220 . Bolt  232  turns into nut  230 , which shiftably seats in a second longitudinal slot  227  formed in the bottom of shoe  220 . Tightening bolt  232  locks shoe  220  in place against mount body  210  to hold the shoe in either the open or locked position. A foot  226  (extends longitudinally from the distal end of shoe  220 , which forms a corresponding “under-hook” for the shoe opposite body protrusion  214 . Similar to protrusion  214 , the distal end of shoe  220  is configured and dimensioned to abut against the rounded contour of side edge  122  of rail opening  121  and foot  226  is located to receive side edge  122  between the foot and bottom surface  212 . A coil spring  218  is disposed between protrusion  214  and shoe  220  to urge the shoe towards its unlocked position. One end of spring  218  is seated within a longitudinal bore  217  formed in protrusion  214  and the other end is seated in a shallow longitudinal bore  227  in shoe  220 . A second string  240  is seated within a bore  241  within mount body  210  which slightly urges shoe  220  away from bottom surface  212 . 
     Light mount  200  attaches to rail section  100  by manually pressing shoe  220  inward against protrusion  214  and tightening bolt  232  to hold the shoe in the unlocked position. Once secured in the unlocked position, shoe  220  and protrusion  214  are inserted into rail opening  121 . Once inserted, bolt  232  is loosened allowing shoe  220  to slide away from protrusion  214  under the force of spring  218  to the locked position. In the locked position, protrusion  214  and shoe  220  abut against the opposite rounded end edges  124  of rail opening  121  with feet  216  and  226  seated against the inner surface  114  of rail body  110 . Once shoe  220  is in the locked position, bolt  232  is tightened securing shoe  220  against mount body  210  within rail opening  121 . Mount  200  detaches from rail section  100  by loosening bolt  232 . Once bolt  232  is loosened, mount body  210  is manually shifted within rail opening  121  towards the “shoe end” which compresses spring  218  and allows protrusion  214  to be pivoted outward from rail opening  121 . Once the protrusion is freed, mount  200  can be fully removed from rail section  100 . 
       FIGS. 6 and 7  illustrate a second embodiment of an RIS mount interface of this invention, designated generally as reference numeral  300 , for use with the exemplary embodiment of a weapon rail panel  100 . Mount interface  300  is designed to affix to or be incorporated into a rail accessory, such as a light, lazer, foregrip, bi-pod and the like. As shown, interface body  310  is affixed to the rail accessory (not shown) by fasteners that turn into threaded lateral bores in the accessory. Mount interface  300  permits a secure connection between the rail accessory and the rail section regardless of any variations in the wall thickness of the rail section. 
     Mount interface  300  includes an interface body  310  and two sliding shoe elements  320  and  330 . Interface body  310  is adapted to support or integrate into the rail accessory (not shown). Interface body  310  has a U-shaped side profile with a bottom (i.e., the side facing the rail) recessed opening  311 . Shoe element  320  is an L-shaped body having an elongated body  322  and an integrated leg  324 . An integral foot  326  extends outward longitudinally from the distal end of leg  324 . Shoe element  330  is a rectangular shaped body that slidingly nests against the bottom of shoe element  320 . Shoe element  330  has an elongated main body  332  that terminates at one end in a foot  316  that extends parallel to bottom surface  336 . Shoe bodies  322  and  332  are configured and dimensioned to seat within rail opening  121 . Similiarly, feet  326  and  336  are configured and dimensioned to abut against the rounded contour of side edge  122  of rail opening  121 . 
     Shoe element  320  shiftably sits within recessed bottom  311  of interface body  310  for longitudinal movement within the interface body. Similarly, shoe element  330  shiftably abuts against shoe element  320  for longitudial movement relative to shoe element  320  within recessed openinng  311  of interface body  310 . Mount interface  300  also includes a spring  350  seated between shoe elements  320  and  330  to bias the shoe elements apart. Spring  350  seats within opposed bores  325  and  335  in each shoe element. 
     Shoe elements  320  and  330  are connected to interface body  310  by a fastener  340  that extends through an aligned hole  313  in interface body  310  and an elongated slot  323  in shoe element  320  and turns into a threaded bore  333  in shoe element  330 . Fastener  340  also “locks” shoe elements  320  and  330  relative to one another in either a “released” or “locked” positions. Tightening bolt  340  locks shoe elements  320  and  330  in place against interface body  310  to hold the shoe in either the “released” or “locked” positions. 
     Interface mount  300  connects to rail section  100  by pressing and locking shoe elements  320  and  330  together to fit within rail opening  121 . Next, shoe elements  320  and  330  of interface mount  300  are seated within the selected rail opening  121  and fastener  350  is loosened to “unlock” the shoe elements. Once “unlocked”, spring  350  urges shoe elements  320  and  330  apart to engage against the opposite rounded end edges  124  of rail opening  121  with feet  316  and  326  seated against the inner surface  114  of rail body  110 . Once engaged, fastener  350  is tightened to “lock” shoe elements  320  and  330  in place relatively to one another and against end edges  124  of rail opening  121  thereby securing interface mount  300  to rail section  100 . 
     Conversely, interface mount  300  detaches from rail section  100  by loosening fastener  350 . Once loosened, interface body  310  is manually manipulated within rail opening  121  to compresses shoe element  330  against shoe element  320  so that interface mount  300  can be withdrawn from rail opening  121 . In some instances, the fastener  350  can be tightened again to “lock” the shoe element in place facilitating the withdrawal from rail opening  121 . 
     It should be noted that the two shoe element design allows interface mount  300  to adjust and compensate for variations in the wall thickness of rail body  120 . When fastener  350  is tightened, both shoe elements  320  and  330  are pressed uniformly against the rail body, which is pressed against the bottom of interface body  310 . Because both shoe elements are independently connected to interface body  310 , interface mount  300  can be fitted to any rail section with a compatible slot dimension independent of the wall thickness of the rail section. 
     It should be apparent from the foregoing that an invention having significant advantages has been provided. While the invention is shown in only a few of its forms, it is not just limited but is susceptible to various changes and modifications without departing from the spirit thereof. The embodiment of the present invention herein described and illustrated is not intended to be exhaustive or to limit the invention to the precise form disclosed. It is presented to explain the invention so that others skilled in the art might utilize its teachings. The embodiment of the present invention may be modified within the scope of the following claims.