Abstract:
A system for mounting a plurality of tactical attachments to firearms having a magazine tube is disclosed. Tactical attachments or devices such as laser illumination sights, flashlights, magazine extension tubes, and breaching tools are interchangeable and attached with a single adapter mounted to the end of a magazine ammunition tube. Adapters of varying lengths provide increased ammunition capacity. The tactical devices have a common mounting structure for mating to the adapter, which includes a locking ring to assure the tactical device cannot become dislodged from the adapter during firearm usage. The adapter/tactical device interface allows rapid swapping of tactical devices without the need of tools.

Description:
REFERENCES TO PRIOR APPLICATIONS 
     This application is related to provisional application, reference no. 61/639,950 filed Apr. 30, 2012, entitled SHOTGUN TACTICAL ULTRA-ILLUMINATION DEVICE OR THE ACRONYM: S.T.U.D., and claims benefit thereof. Provisional application no. 61/639,950 is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     The invention relates to the design and structure of attachments and their mounting system for firearms. More specifically, the invention relates to tactical attachments mounted to the ammunition magazine tube of long guns and shotguns. 
     Users of firearms often attach removable devices such as laser sights, flashlights, and other accessories to their weapon. Typically, these attachments require special brackets and mounting systems which are expensive and custom built, each “tactical” device or attachment having its own bracketing or mount. These custom mounts further require alignment with the firearm&#39;s point of aim, which can be time consuming to set up and are subject to misalignment if physically bumped during use. Some bracketing interferes with the use of the aiming sights on the weapon which can further hinder use. 
     If the weapon stores ammunition in a tubular style magazine, tactical attachments may be mounted to the end of the ammunition tube, replacing the stock cap employed by the manufacturer. This mounting method has the advantage of automatic alignment with the weapon&#39;s point of aim. Typically, this method has been utilized with pump style shotguns, although it may also be employed with other longs guns having tube magazines such as lever action rifles, for example. 
       FIG. 1  (prior art) is a side view  100  of a shotgun having an ammunition tube  106 . Ammunition tube  106  and pump slide  104  are situated below the barrel  102 . Ammunition spring  110  provides the force to feed ammunition (not shown) in the action of the weapon (not shown) for firing. Spring  110  is held within the ammunition tube  106  via cap  112  which is threaded onto ammunition tube  106  via threads  108 . 
     Patent Application Publication US 2010/0277896 A1 by Oehlkers discloses an example of a flashlight threaded on to the ammunition tube of a shotgun. The device combines a flashlight with extended ammunition capacity. One weakness of this approach is that a special flashlight device must be manufactured for every make and model of shotgun or long gun, which can be expensive for owners of multiple weapons. Another weakness is that the ammunition spring  110  is exposed every time the flashlight is removed or replaced with another device, which can lead to the spring launching from the ammunition tube  106  as the attachment is removed. It may also be difficult to re-install the spring if the magazine tube is full of ammunition. This can prove to be disruptive, particularly for peace officers or military personnel who rely on rapid exchange of tactical attachments during moments of high duress. Further, a thread on device  202 , such as that shown in  FIG. 2 , may have the activation switch  204  end up in different locations, depending on the starting position prior to threading the unit  202  on. This can be troubling for military and peace officers who require “hands off” familiarity of their weapon, and can ill afford taking their eyes from the sight picture ahead to find the flashlight on/off switch. 
     U.S. Pat. No. 5,727,346 to Lazzarini et. al. discloses a device for mounting a flashlight or similar device into a holder attached to (below) slide  104 . This system has the disadvantage that the device is mounted to a movable part, and therefore the accuracy (particularly of a laser illumination sight) is questionable. Furthermore, tactical attachments such as door breaching tools or ammunition extension tubes are not compatible with this mounting system. 
     U.S. Pat. No. 6,565,226 to Cummings discloses flashlight mounting system wherein the flashlight is mounted with a portion of the ammunition tube  106 . This system has the disadvantage of consuming ammunition capacity, as a significant portion of the flashlight is mounted within the ammunition tube. It also requires the use of tools for the removal of the flashlight and adapters which would not be suitable for military or police field use. It is also suitable only for the larger gauge shotgun calibers, due the outside diameter requirements of the flashlight. 
     These and other limitations of the prior art will become apparent to those of skill in the art upon a reading of the following descriptions and a study of the several figures of the drawing. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a system for mounting tactical attachments to a firearm having an ammunition tube and an ammunition spring mounted therein, including a tactical attachment adapter having an ammunition tube mounting end and an opposing tactical attachment mounting end, the ammunition tube mounting end removably mounted to the end of the ammunition tube of the firearm, the tactical attachment mounting end having a cavity fashioned therein, the mounting end having one or more pins extending into the cavity; and a tactical attachment having a mounting structure, the mounting structure having a first portion and a second portion, the first portion of the mounting structure having one or more “J” shaped slots fashioned within an outer surface, the mounting structure being inserted into the cavity fashioned within the tactical attachment adapter such that one or more pins extending into the cavity are engaged within a hook portion of the “J” shaped slots, the second portion of the tactical attachment mounting structure containing a locking ring engaging an external threaded surface on the tactical attachment mounting structure, the locking ring operative to provide tension between said tactical attachment and said tactical attachment adapter. 
     These and other embodiments, features and advantages will become apparent to those of skill in the art upon a reading of the following descriptions and a study of the several figures of the drawing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Several example embodiments will now be described with reference to the drawings, wherein like components are provided with like reference numerals. The example embodiments are intended to illustrate, but not to limit, the invention. The drawings include the following figures: 
         FIGS. 1  (Prior Art) is a side view of a shotgun having an ammunition tube; 
         FIG. 2  (Prior Art) is a side view of a shotgun having a flashlight threaded on to the end of a magazine tube; 
         FIG. 3  is a profile side view of a tactical attachment system, in accordance with example embodiments of the present invention; 
         FIG. 4   a  is a partial cross section view of a tactical attachment adapter mounted on a magazine tube, in accordance with an example embodiment of the present invention; 
         FIG. 4   b  is a partial cross section view of a tactical attachment adapter mounted on a magazine tube, and mounted to a typical tactical attachment, in accordance with an example embodiment of the present invention; 
         FIG. 4   c  is a partial cross section view of a “bore through” version of the tactical attachment adapter, in accordance with an example embodiment of the present invention; 
         FIG. 4   d  is an end view of the tactical attachment adapter of  FIG. 4   a , in accordance with an example embodiment of the present invention; 
         FIG. 5   a  is a partial cross section view of an extended length tactical attachment adapter mounted on a magazine tube, in accordance with an example embodiment of the present invention; 
         FIG. 5   b  is a partial cross section view of an extended length tactical attachment adapter mounted on a magazine tube, and mounted to a typical tactical attachment, in accordance with an example embodiment of the present invention; 
         FIG. 5   c  is a partial cross section view of a “bore through” version of the extended length tactical attachment adapter, in accordance with an example embodiment of the present invention; 
         FIG. 5   d  is an end view of the extended length tactical attachment adapter of  FIG. 5   a , in accordance with an example embodiment of the present invention; 
         FIG. 6  is a side view of a laser sight tactical attachment, in accordance with an example embodiment of the present invention; 
         FIG. 7  is a side view of a flashlight tactical attachment, in accordance with an example embodiment of the present invention; 
         FIG. 8  is a side view of a flashlight tactical attachment, having stun gun electrodes, in accordance with an example embodiment of the present invention; 
         FIG. 9   a  is a side view of a shotgun having a tactical attachment adapter and a breaching tool tactical attachment mounted, in accordance with an example embodiment of the present invention; 
         FIG. 9   b  is a cross section view of a breaching tactical attachment, in accordance with an example embodiment of the present invention; 
         FIG. 9   c  is a partial cross section view of a “bore through” version of a breaching tactical attachment, in accordance with an example embodiment of the present invention; 
         FIG. 10   a  is a side view of a magazine capacity extension tube tactical attachment, in accordance with an example embodiment of the present invention; 
         FIG. 10   b  is a partial cross section view of a magazine capacity extension tube tactical attachment, in accordance with an example embodiment of the present invention; and 
         FIG. 11  is a side view of a tactical attachment cap, in accordance with an example embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Example embodiments of the subsequently disclosed present invention provide significant improvements over the heretofore described prior art. The present invention discloses a system for a wide variety of tactical attachments that can be added to long guns with tube magazines or shotguns with tube magazines. The system provides a standardized mounting geometry for all tactical attachments that are mounted to custom adapters designed for each individual firearm. The adapters provide fast insert and lock mechanisms with a locking collar to prevent loosening of the tactical attachment. In some embodiments, the magazine spring is fully contained by the adapter, even with the tactical attachment removed, so there is no possibility of loosing the spring or having to re-insert the spring during the swap of different attachments. A wide variety of tactical attachments are accommodated with this system, including (but not limited to) flashlights, laser illumination sights, door breaching tools, and magazine capacity extension tubes. 
       FIG. 3  is a profile side view  300  of a tactical attachment system, in accordance with example embodiments of the present invention. As an example, a pump style shotgun (as shown in  FIG. 1 ) is used to illustrate the application of embodiments of the present invention, although it is understood that other suitable weapons having tube ammunition magazines may also be utilized, as can be appreciated by those skilled in the art. Adapters  302 ,  304  are threaded on to ammunition tube  106  via threads  108 . The differences between adapters  302  and  304  are discussed further below. Tactical attachments laser illumination sight  306 , flashlight  308 , and breaching tool  310  all have a common mounting geometry, which is designed to interchangeably fit the receiving portion of adapters  302 ,  304 . In the field or during use of the firearm, interchange of any of the tactical attachments  306 ,  308 , or  310  can be accomplished without tools or the removal of adapter  302  (or  304 ). This flexibility allows the owner of the firearm to purchase and stock different adapters designed for individual weapons, but use a common selection of tactical attachments for all firearms. Significant cost savings can be realized, particularly for military organizations or large law enforcement departments, as the purchase of a large number of tactical attachments designed for individual weapons is no longer required. 
       FIGS. 4   a - 4   d  disclose details of adapter  302 .  FIG. 4   a  is a partial cross section view  400  of a tactical attachment adapter  302   a  mounted on a shotgun magazine tube  106 , in accordance with an example embodiment of the present invention. In this example version  302   a  of adapter  302 , ammunition spring  110  is contained by piston  402 , which provides containment of the spring  110  once the adapter  302   a  is threaded onto the magazine tube  106 . Piston  402  is freely mounted within the bore of adapter  302   a , allowing the spring force to be transmitted to any tactical attachment coupled to the adapter (see  FIG. 4   b ). Adapter  302   a  has pins  404  designed to engage fabricated slots in the mounting adapter portion of a tactical attachment (see also  FIG. 4   b ). Adapter  302   a  is designed to be permanently mounted to the ammunition tube  106 , serving the purpose of cap  112 , allowing full functionality of the weapon, with or without tactical attachments connected. 
       FIG. 4   b  is a partial cross section view  401  of a tactical attachment adapter  302   a  mounted on a magazine tube  106 , mounted to an example tactical attachment mating structure  406 , in accordance with an example embodiment of the present invention. The mating portion of a typical example tactical attachment  406  has a fabricated slot  410  designed to engage pins  404  of adapter  302   a . Slot  410  is generally fabricated in the shape of a squared off “J”, with an entrance section (the leg of the “J”) and a re-entrant pin locking section (the “hook” on the “J”). When mating a tactical attachment  406  to the adapter  302   a , the tactical attachment  406  is oriented so the pins  404  engage the entrance section of slot(s)  410 . The tactical attachment  406  is then pushed in to the mounting cavity of adapter  320   a  until the rear mounting surface of the tactical attachment  406  contacts piston  402 . Further insertion of tactical attachment  406  compresses spring  110  via rearward movement of piston  402 , until pins  404  contact the base of the “J”. Tactical attachment  406  is then rotated until pins  404  are aligned with the re-entrant pin locking section, then released. The slight forward motion of the tactical attachment  406  is aided by compressed spring  110  and piston  402  until pins  404  are locked in the hook portion of slot  410 . Locking collar  408  is back threaded against the front face of adapter  302  once pins  404  are properly captured by the re-entrant geometry of slot  410 . 
       FIG. 4   c  is a partial cross section view  403  of a “bore through” version  302   b  of the tactical attachment adapter, in accordance with an example embodiment of the present invention. In this example version, piston  402  is removed, allowing spring  110  to be directly engaged against the rear mounting surface of tactical attachment  406 . This example embodiment is useful for extending magazine ammunition capacity, but has the potential disadvantage of exposing the open end of the spring while changing tactical attachments.  FIG. 4   d  is an end view  405  of the tactical attachment adapter  302   a  of  FIG. 4   a , in accordance with an example embodiment of the present invention. In this view the two diametrically opposed engagement pins  404  are indicated, which mate with corresponding diametrically opposed fabricated slots on the coupling portion of the tactical attachments  406  (not shown). In the example embodiment of  FIGS. 4   a - 4   d , two engagement pins  404  are provided on the adapter. However, as can be appreciated by those skilled in the art, only one pin is essential for operation. Likewise, only a single slot  410  required on each tactical attachment, although having two slots diametrically opposed aids in rapid engagement of the attachments as there are two possible engagement positions, as opposed to only one. 
       FIGS. 5   a - 5   d  disclose details of adapter  304 .  FIG. 5   a  is a partial cross section view  500  of an extended length tactical attachment adapter  304  mounted on a magazine tube  106 , in accordance with an example embodiment of the present invention. The difference between adapters  302  and  304  is that adapter  304  allows for further expansion of the ammunition spring  110 , by extending the dimension between the end of the ammunition tube  106  and the rear of piston  502 , over that provided by adapter  302 . This extended length allows for more ammunition to be stored within the ammunition tube. Adapter  304   a  provides for extended ammunition capacity without the need for separate ammunition tubes (which would prohibit the use of other tactical attachments) or a bore through adapter (which can make changing tactical attachments more difficult due to the exposed magazine spring). Piston  502  and pins  504  serve the same purpose as previously described for piston  402  and pins  404  in  FIGS. 4   a - 4   d.    
       FIG. 5   b  is a partial cross section view  501  of an extended length tactical attachment adapter  304   a  mounted on a magazine tube  106 , mounted to an example tactical attachment mating structure  406 , in accordance with an example embodiment of the present invention.  FIG. 5   c  is a partial cross section view  503  of a “bore through” version  304   b  of the extended length tactical attachment adapter, in accordance with an example embodiment of the present invention.  FIG. 5   d  is an end view  505  of the extended length tactical attachment adapter  304   a  of  FIG. 5   a , in accordance with an example embodiment of the present invention. 
       FIG. 6  is a side view  600  of a laser illumination sight tactical attachment  306 , in accordance with an example embodiment of the present invention. This sight produces a narrow beam of visible red or infrared light, projecting an illuminated “dot” at the intended aim point of the weapon it&#39;s mounted on. Typically, the light source is a solid state laser diode  604 . To be used effectively, the laser illumination sight  306  must be mounted securely on the weapon, and must remain in alignment during handling and recoil after discharge. Mounting the laser sight coaxial with the ammunition tube assures alignment with the sight axis of the firearm. The slight displacement from the actual axis of the barrel is a minor issue when used with shotguns, and can be easily compensated for on a long gun. The mating end of laser sight  306  has the fabricated slot  410  required for compatible mounting with pins  404 , 504  in adapter  302  or  304 . Knurled ring  408  is back threaded against the adapter body once the pins  404 , 504  are engaged within slot  410 , holding the laser sight  306  firmly on the weapon. Turning the laser on and off is accomplished with a rotary actuated switch  602 . This switch provides tactile feedback with detents to confirm the “on” status of the laser. In one example embodiment, the laser illumination sight  306  is powered with batteries that are contained within the enclosure (not shown). As would be evident to those skilled in the art, the laser illumination sight can be used whether mounted to a tactical attachment adapter or not. 
       FIG. 7  is a side view  700  of a flashlight tactical attachment  308 , in accordance with an example embodiment of the present invention. Flashlight  306  is equipped with the same mounting structure as shown for the laser illumination sight  306 . Flashlight  306  may use LEDs (either visible or infrared) or incandescent bulbs to provide illumination. A rotary actuated switch  702  is also provided on the flashlight, which allows the operator to operate the flashlight without removing their eyes from the sight picture ahead of the weapon. In one example embodiment, the flashlight  308  is powered with batteries that are contained within the enclosure (not shown). As would be evident to those skilled in the art, the flashlight can be used whether mounted to a tactical attachment adapter or not. 
       FIG. 8  is a side view  800  of a flashlight tactical attachment  309 , having stun gun electrodes  804 , in accordance with an example embodiment of the present invention. The built in stun electrodes provide a non-lethal option for disabling subjects. This is accomplished by providing a very high voltage, low current electrical discharge at electrodes  804 . Rotary switch  802  provides control of both lighting and stun functions. In one example embodiment, the flashlight  309  is powered with batteries that are contained within the enclosure (not shown). As would be evident to those skilled in the art, the flashlight and stun functions can be used whether mounted to a tactical attachment adapter or not. 
       FIGS. 9   a,b,c  disclose details of an example breaching attachment of the present invention. A breaching tool is typically an extension placed at the muzzle end of shotguns, with a saw-toothed end protruding beyond the end of the muzzle. The jagged edge is placed firmly against a surface and the shotgun is discharged. This tool is primarily used by military and law enforcement personnel to blow out locks and door hinges to allow forced entry to buildings and enclosed rooms.  FIG. 9   a  is a side view  900  of a shotgun having a tactical attachment adapter  302  and a breaching tool tactical attachment  310  mounted, in accordance with an example embodiment of the present invention. Breaching tool  310  is generally cylindrically shaped, having a jagged toothed end structure, which must protrude beyond the end of the barrel  102  by a distance  902 . The teeth  904  fashioned into the end of breaching tool  310  are designed to firmly dig into the surface close to where the projectiles from the firearm will be discharged, to hold the muzzle firmly in place during discharge, and focus the destructive force. Use of the breaching tool requires firm mounting to the shotgun which is aided by locking ring  408 , particularly during discharge and recoil of large 10 and 12 gauge shotguns. 
       FIG. 9   b  is a cross section view  901  of a breaching tactical attachment  310   a , in accordance with an example embodiment of the present invention. This embodiment provides for the standard breaching tactical attachment. Note that this breaching attachment  310   a  can be rapidly exchanged with any of the foregoing tactical attachments without worry of the magazine spring being dislodged during the exchange, when used with adapters  302   a  or  304   a . Rapid exchange with for example, the flashlight  308 , can be useful to military or law enforcement personnel who, subsequent to breaching doors, must proceed into darkened rooms. 
       FIG. 9   c  is a partial cross section view  903  of a “bore through” version of a breaching tactical attachment  310   b , in accordance with an example embodiment of the present invention. The bore through version  310   b  provides for increased magazine capacity by allowing the magazine spring  110  to extend the majority of the length of the breaching tool. A shallow plug  906  is inserted from the toothed end of the breaching attachment to provide a stop for spring  110 . 
       FIG. 10   a  is a side view  1000  of a magazine capacity extension tube tactical attachment  312 , in accordance with an example embodiment of the present invention. The magazine extension tube provides increased ammunition capacity by extending the volume of the ammunition tube  106 . A cross section view  1001  is shown in  FIG. 10   b . The magazine capacity extension tube must be used with bore through adapters to obtain an increase in ammunition capacity, so swapping with other tactical attachments requires the compression of the magazine spring during the exchange. 
       FIG. 11  is a side view  1100  of a tactical attachment cap, in accordance with an example embodiment of the present invention. The cap may be useful for enclosing the open end of adapters  302   a  and  304   a  when no tactical attachments are mounted, to prevent the contamination of the piston mechanism with dirt and debris. The cap is required to seal bore through type adapters and provide an engagement surface for the magazine spring, when no tactical attachments are mounted. 
     Although various embodiments have been described using specific terms and devices, such description is for illustrative purposes only. The words used are words of description rather than of limitation. It is to be understood that changes and variations may be made by those of ordinary skill in the art without departing from the spirit or the scope of various inventions supported by the written disclosure and the drawings. In addition, it should be understood that aspects of various other embodiments may be interchanged either in whole or in part. It is therefore intended that the claims be interpreted in accordance with the true spirit and scope of the invention without limitation or estoppel.