Patent Publication Number: US-9851180-B2

Title: Firearm accessory locking structure

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of priority to and is a continuation in part of U.S. application Ser. No. 14/555,875 filed on Nov. 28, 2014. The content of U.S. application Ser. No. 14/555,875 filed on Nov. 28, 2014 is incorporated by reference herein in its entirety. This application also claims the benefit of priority to and is a continuation in part of U.S. application Ser. No. 14/949,428 filed on Nov. 23, 2015. The content of U.S. application Ser. No. 14/949,428 filed on Nov. 23, 2015 is incorporated by reference herein in its entirety. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable. 
     THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT 
     Not Applicable. 
     INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC 
     Not Applicable. 
     BACKGROUND OF THE INVENTION 
     (a) Field of the Invention 
     The device described in this application is a locking mechanism for accessories that may be attached to firearms. More specifically, this application describes a mechanism that is used to stabilize an accessory that is attached to the frame of a firearm. 
     (b) Background Art 
     There are a variety of firearm accessories already in existence that are designed to releasably attach to a firearm so that the operator of the firearm can use both the accessory and the weapon at roughly the same time. For example, weapon mounted lights are used in conjunction with a firearm to aid low light target identification, allowing the user to simultaneously aim and illuminate the target. These lights can be handheld or mounted to the weapon, with the light beam parallel to the bore. Such lights are commonly used by officers of tactical agencies such as military, government, local, state and federal agencies in the field and for training during daylight, low and/or no light conditions. Weapon mounted lights are mounted on rifles, shotguns, submachine guns and handguns. These lights offer hands-free use, leaving the operator free to use both hands to control the weapon. 
     Generally, firearm accessories attach to some portion of the frame of the firearm and may have a second component that stabilizes the accessory by engaging with a discrete part of the firearm frame or rail system. For example, in U.S. patent application Ser. No. 14/949,428 this inventor has disclosed a system for attaching a firearm accessory to a firearm using a rail system integrated into the handgun frame. The accessory has two rails that are substantially parallel and are complementary to two substantially parallel rails that are located on the frame of a firearm. The device is fitted onto the rail system of a firearm and the locking mechanism is engaged with a perpendicular impression that is located between the parallel rails on the forearm frame. The device features a thumb screw that allows the user to easily tighten or loosen the accessory on the firearm frame. 
     However, in making these devices easy to attach and detach, manufacturers have made the devices easier to lose especially during training exercises. In this inventor&#39;s personal and professional experience, live fire training that does not also simulate the use of the firearm mounted accessory does not adequately prepare individuals for using their firearms in real life combat situations. In other words, without the proper training, the average firearms operator will draw and fire their weapon considerably more slowly when their firearm has an accessory attached to it as compared to how fast they draw and fire the same weapon without the accessory attached. The use of firearm accessories during training exercises also gives the user an opportunity to take the accessory off of the firearm and to lose it. Moreover, there are opportunities for the attachment means of the accessory to become loose and to disengage from the firearm. 
     As a result, there is a need in the firearms industry for an accessory that can be easily and releasably mounted to a firearm and that allows the user to lock the accessory onto the firearm so that the user cannot easily disengage and separate the accessory from the firearm. 
     BRIEF SUMMARY OF THE INVENTION 
     The device described in this application is an inexpensive and sturdy mechanism that can be used to lock an accessory on a firearm. The device is meant to be used with both actual or real and functional firearm accessories as well as dummy, replica or artificial accessories that merely simulate the look and feel of a functioning firearm accessory. 
     One of the preferred embodiments of the presently disclosed device is designed to work with an artificial or replica firearm accessory with a body having a bore extending through the inner diameter of the firearm accessory body. While the bore could simply be a hole extending through the interior and exterior of the accessory body, in a preferred embodiment of the device, the interior of the bore features threads. The locking mechanism further features a locking screw inserted into the bore. A preferred embodiment of the device features threads on the exterior of the locking screw that are complementary to the threads on the interior of the bore. As a result, in preferred embodiments of this device the locking screw can be threaded into the bore. In addition, preferred embodiments include a second screw, ideally a thumb screw, positioned at one end of the bore with a screw body that passes through the bore to contact the locking screw. When the user turns the thumb screw, the tip of the thumb screw engages the locking screw causing it to turn in the bore in which it is situated. Thus the user can use the thumb screw to advance the locking screw until it contacts another structure located at or within the bore. 
     In the preferred embodiments of this device, at that opposite end of the bore, there is a platform featuring a raised ridge that is shaped to engage a corresponding portion of the firearm frame. As a result, when the user turns the thumb screw, the user causes the locking screw to advance in the bore of the device until the locking screw contacts the undersurface of the platform. Alternately, the locking screw can be used to contact and compress a spring positioned between the tip of the locking screw and the underside of the platform. Further turning the thumb screw causes the platform to move from a first retracted position to a second extended position. The unique functioning of this device is a result of the locking screw that, once advanced in the bore sufficiently to cause the platform to raise into its extended position, then stays in place until or unless the user uses a separate tool to loosen the locking screw. The user thereby locks the accessory onto the firearm frame preventing the user from removing the accessory from the firearm by simply turning the thumb screw in the opposite position. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  is an x-ray side view of a firearm accessory featuring the locking mechanism; 
         FIG. 2  is an x-ray side view of a firearm accessory featuring the locking mechanism; and 
         FIG. 3  is an exploded view of a firearm accessory featuring the locking mechanism. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the invention in more detail, in  FIG. 1  there is shown an x-ray view of a firearm accessory featuring the locking mechanism, generally  10 . The firearm accessory has a rigid body  11  featuring a bore  12  that passes completely through the interior and exterior of the body  11  such that each end of the bore  12  is accessible from the outside of the accessory. The bore  12  has a first end  13  and a second end  14 . The locking mechanism  10  also features a locking screw  15  that is inserted in the first end  13  of the bore  12 . In one preferred embodiment, the locking screw  15  is a set screw. In other preferred embodiments, the locking screw  15  is a jam socket screw. For convenience, when the various embodiments of this device are discussed, the term “locking screw” will be used and is meant to refer to a set screw, a jam socket screw and/or their functional and structural equivalents. 
     In addition, the locking mechanism  10  includes a screw  16  that is inserted into the first end  13  of the bore  12  after the locking screw  15  is placed into the bore  12 . In the preferred embodiment and best mode of this device, the screw  16  is a thumb screw. The locking mechanism also includes a platform  17  with a raised edge or protrusion  18  that is placed over the second end  14  of the bore  12 . Moreover, in the preferred embodiment and best mode of the locking mechanism  10 , the platform features a hole  19  that is comparable in diameter to the diameter of the bore  12 . Also, the preferred embodiment of the locking mechanism  10  includes a spring  20  inserted into the bore  12  from the second end  14  of the bore  12 , such that it is located immediately underneath the platform  17 . 
     The locking mechanism  10  in  FIG. 1  is assembled by inserting or threading the locking screw  15  into the first end  13  of the bore  12 . Next the thumb screw  16  is threaded into the first end  13  of the bore  12 . As previously discussed, in preferred embodiments of the locking mechanism  10 , the set screw  15  has external threads (not shown) that are complementary to threads lining the interior of the bore  12 . In addition, the exterior surface of the thumb screw  16  also features threads (not shown) that are complementary to the threads lining the interior of the bore  12 . The spring  20  can be inserted into the bore from either end, but generally a user will insert the spring  20  into the bore  12  from the second end  14  of the bore  12 , after the locking screw  15  and thumb screw  16  are inserted into the first end  13  of the bore  12 . Once the spring  20  is in place, the platform  17  is seated over the second end of the bore. By tightening the thumb screw  16 , the user can cause the locking screw  15  to advance or thread further into the bore  12  to contact and compress the spring  20  between the platform  17  and the locking screw  15  thereby applying upward force to the bottom surface of the platform  17 . This upward force will help keep the platform  17  featuring the protrusion  18  flush against the firearm frame until the locking screw is loosened. 
     In more detail, the diameter of the threaded portion of the thumb screw  16  has to be similar enough to the diameter of the bore  12  such that the thumb screw can be snugly threaded into the bore  12 . This necessarily means that the diameter of the hole  21  in the locking screw  15  must be smaller than the diameter of the thumb screw  16  and the bore  12 . Otherwise, it would be impossible to use the thumb screw  16  to thread the locking screw  15  into the bore  12 . 
     Referring now to the invention in more detail,  FIG. 2  shows an x-ray view of a firearm accessory, generally  30 , featuring the locking mechanism  10  attached to the frame of a firearm  31 . Generally, a firearm accessory  30  will have a primary means of attaching to the firearm and a secondary means of attachment meant to stabilize the accessory once it is attached using the primary means. For example, as previously discussed, there are a variety of rail systems that are commonly used to attach accessories to firearm frames. Firearm accessories that are designed to be attached to these rail systems have structures on their outer surfaces that are meant to be complementary to the rails and allow the firearm to attach to the rail system. Such a system has been disclosed by this inventor in U.S. patent application Ser. No. 14/949,428. The locking mechanism  10  disclosed herein is meant to complement or replace the secondary means of attachment that stabilize the accessory on the firearm frame. More specifically, once the accessory  30  is attached to the rails of the firearm  31 , the thumbscrew  16  is turned and thus turns the locking screw  15  and advances it upwards in the bore  12  towards the spring  20  and platform (not shown). As the locking screw  15  advances into the bore  12 , it compresses the spring  20  and provides tension that forces the platform against the firearm frame securing the accessory to the firearm  31 . Alternately, the device can work without the spring  20 . In such embodiments, the locking screw  15  contacts the underside of the platform (not shown) and engages the platform directly. 
     Once the locking screw  15  is securely engaged with the spring  20  and/or the platform  17 , the thumbscrew  16  can be removed from the device without the locking screw  15  being loosened or repositioned. Thus, the platform  17  featuring the protrusion stays in place, engaged with the frame of the firearm  31 . This can be an advantage in training scenarios in which the instructor does not want the user to be able to accidentally or intentionally remove the accessory from the firearm. Even with the thumbscrew  16  removed, the locking screw  15  is held securely in place by the complementary threading on the locking screw and the interior of the bore  12 . 
     As noted, the thumbscrew  16  advances the locking screw  15  into the bore  12 , but in the preferred embodiment, the thumb screw  16  does not attach to the locking screw  15  such that when the thumb screw  16  is unthreaded, removed or backed out of the device, it does not unthread, remove or back out the locking screw  15 . As a result, to remove the accessory  30  from the firearm  31 , the user must insert a tool into the bore  12  to turn the locking screw  15  such that it disengages with the threads inside the bore  12 . As the locking screw  15  is backed out of the bore  12 , it ceases to apply force to the platform  17  or the spring  20  and the platform in turn ceases to be engaged with the frame  31  of the firearm  30 . As previously mentioned, preferred embodiments of this device can use different structures as the locking screw  15 . In one embodiment, the locking screw  15  is a set screw with a screw drive that is shaped to fit a standard tool such as a screw driver. In this embedment, the user will remove the thumb screw  16  and then insert the tip of a screw driver or similar tool into the screw drive (not shown) of the set screw  15 , allowing the user to turn the set screw such that it backs out of the bore  12 . Alternately, the locking screw  15  can be a jam socket screw with a hole  21  in its center that can accommodate a hex key, Allen Key or Allen Wrench or other tool that can be used to turn or unscrew the screw and remove it from the bore  12 . In this embodiment, the user will still likely remove the thumb screw  16  before trying to “unlock” the device. The user can then insert a tool such as an Allen wrench into either the first end  13  of the bore  12  or the second end  14  of the bore through the hole  19  in the platform  17 . The tool can be used to engage the hole  22  in the jam socket screw  15  thus allowing the user to turn the jam socket screw  15  and remove it from the bore  12  altogether or simply to reposition it within the bore  12  so that it can be later used to lock the accessory  30  onto the same or a different firearm  31 . 
       FIG. 3  is an exploded view of a firearm accessory featuring the embodiment of the locking mechanism  10  using a socket jam screw  21 . The locking mechanism  10  in  FIG. 3  is assembled by inserting or threading the socket jam screw  21  into the first end  13  of the bore  12 . Next the thumb screw  16  is threaded into the first end  13  of the bore  12 . The spring  20  can either be inserted into the first end  13  of the bore  12  prior to inserting the set or socket jam screw  15  into the first end  13  of the bore  12 , or it can be inserted into the second end  14  of the bore  12  prior to positioning the platform  17 . Once the spring  20  is in place, the platform  17  is seated over the second end  14  of the bore  12 . By tightening the thumb screw  16 , the user can cause the set screw or socket jam screw  15  to advance or thread further into the bore  12  to contact and compress the spring  20  between the platform  17  and the jam socket screw  15  thereby applying upward force to the bottom surface of the platform  17 . 
     A skilled artisan will appreciate that the various components of this system can be made from a variety of materials, including metals, fiberglass and durable plastics and polymers. In addition, the tip of the thumb screw  16  can be machined as can the head of the locking screw  15  to make the two structures engage each other more firmly making it easier to use the thumb screw  16  to screw or unscrew the set screw  15 . 
     Reference throughout the specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present invention should be or are in any single embodiment of the invention. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, discussion of the features and advantages, and similar language, throughout the specification may, but do not necessarily, refer to the same embodiment. 
     Furthermore, the described features, advantages, and characteristics of the invention may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the invention can be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the invention. 
     It is understood that the above described embodiments are only illustrative of the application of the principles of the present invention. The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiment, including the best mode, is to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims, if any, in conjunction with the foregoing description. 
     While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The invention should therefore not be limited by the above described embodiment, method, and examples, but by all embodiments and methods within the scope and spirit of the invention.