Abstract:
A sight mount for a firearm includes a base, a pair of upwardly extending protective ears, and a rearwardly extending platform for supporting an iron sight assembly. The base includes dovetail rails for securing the base to a firearm, and transverse slots for accepting an electronic sight. The protective ears serve to protect the iron sight assembly, particularly when the electronic sight is removed, and also serve to stabilize the iron sight assembly. The sight mount enables a user to either use the electronic sight alone, or the iron sights, by simply shifting the direction of the user&#39;s view into the sight. Alternately, the electronic sight may be removed and the iron sights used directly, without requiring any adjustment of the iron sights.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to telescopic scopes and electronic sights for firearms. More particularly, the present invention relates to devices for mounting optical sights on rifles and other firearms. 
     2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98. 
     Certain rifles, for example the military style rifles commonly known and sold as AR-15 or M-16 rifles, are produced in different models. Some models have fixed iron sights. Other models, known as “flat top” models, are not provided with fixed iron sights, as they are intended instead to accommodate a telescopic scope or an electronic sight of the kind commonly known as a “red dot” sight. 
     The flat top models typically include a mounting configuration which is manufactured to military specifications, and which consists of a series of transverse slots formed in a planar upper surface of the rifle receiver. The slots allow for a scope or electronic sight to be mounted on the rifle at various positions along the axis of the rifle, so as allow for appropriate setting of relief distance between the objective lens of the scope and the eye of the user. Alternately, a carry handle having an iron sight assembly may be affixed to the flat top of the rifle. Such rifles typically include a front site post for the latter purpose. 
     Scopes and optical sights are sometimes mounted directly on the rifle. In such a configuration it is typically not possible to also accommodate an iron sight on the rifle. In some situations a scope or optical sight is mounted on a carrying handle of a military style AR-15 or M-16 rifle, but such mountings are not considered the most desirable because they result in the scope or sight being raised considerably above the barrel of the rifle. 
     In other configurations the scope or optical sight is affixed to a separate mount, which is in turn affixed to the rifle. Such a configuration allows the scope or sight to be removed independently of the mount. One advantage of such a configuration is that the mount may be equipped with an iron sight, which may be used when the optical sight is removed from the rifle. 
     Previously known sight mounts have utilized an iron sight on a tiltable hinge, which allows the iron sight to be swung down and out of the way of the optical sight. When the optical sight is removed, the iron sight is swung upwardly into its ordinary position for use. The disadvantage of such a configuration is that the hinge introduces some inaccuracy into the iron sight. In addition the hinged iron sight, when raised, is exposed in an unprotected position and is thus subject to damage and inaccuracies caused by inadvertent physical impacts. 
     Accordingly, it is the object and purpose of the present invention to provide an improved sight mount for a firearm. 
     In particular, it an object and purpose of the present invention to provide a sight mount which includes an integral iron sight that can be used either when the optical sight is removed or with the optical sight mounted. 
     It is yet another object of the present invention to provide a sight mount that includes an integral iron sight which can be used either alone, with the optical sight removed, or in combination with an electronic sight. 
     More particularly, it is an object and purpose of the present invention to provide a sight mount having an integral iron sight that does not interfere with use of the optical sight alone, but which can alternately be used in combination with the electronic sight, either in its operational mode or in the event of battery or electronic failure of the sight. 
     These and other objects and purposes are attained in the present invention, as described below and defined in the appended claims. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention provides a sight mount for a firearm which includes a base having a forward end and a rear end. The base includes an upper surface having a plurality of transverse slots formed therein and a lower surface having a pair of inwardly directed V-shaped dovetail rails formed therein. The sight mount further includes an integral rear sight platform extending rearwardly from the rear end of the base, and a pair of integral protective ears extending upwardly from the rear end of the base. 
     In the preferred embodiment the rear sight platform includes a vertical bore and an intersecting transverse rectangular bore for receiving a vertical threaded shaft and an elevation adjustment knob, respectively, of an iron sight assembly. The base preferably further includes a concavely curved protective ramp which is integrally formed between the protective ears and which extends upwardly from the rearmost of the transverse slots. 
     These and other features and advantages of the present invention will be apparent from the more detailed description below, when taken with the accompanying drawings and appended claims. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
     The accompanying drawings are incorporated into and form a part of this specification. In the drawings: 
     FIG. 1 is an isometric view of a preferred embodiment of the present invention as it is mounted on a conventional AR-15 or M-16 rifle; 
     FIG. 2 is an isometric exploded view, in partial cross section, of the mount shown in FIG. 1; 
     FIG. 3 is an isometric view of a conventional AR-15 or M-16 rifle having a flat top, military specification sight base. 
     FIG. 4 is an enlarged view of the sight base on the rifle shown in FIG. 3; 
     FIG. 5 is an isometric view of the rifle of FIG. 3, together with the sight mount of the present invention and an electronic sight mounted on the sight mount; 
     FIG. 6 is a rear view of the sight and sight mount of FIG. 5, as viewed from an raised position looking over the iron sight ring; and 
     FIG. 7 is a rear view as in FIG. 6, but viewed with the iron sights aligned with the center aiming dot of the electronic sight. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to the Figures, there is illustrated in FIGS. 1 and 2 a preferred embodiment of a sight mount  10  constructed in accordance with the present invention and mounted on a military style AR-15 or M-16 rifle  12 . 
     The rifle  12  alone is illustrated in FIG. 3, and includes a flat-top type sight base  12   a  which is typically manufactured to military specifications. The sight base  12   a  includes spaced transverse slots  12   b , and V-shaped longitudinal side rails  12   c  which constitute what is commonly referred to as a dovetail mount. The spaced slots  12  permit a scope or other mounting device to be mounted on the sight base  12   a  at various positions along the longitudinal length of the base  12   a , so as to permit appropriate adjustment of the scope for purposes of focusing and also for purposes of providing appropriate eye relief between the scope and the eye of the user. 
     Referring to FIGS. 1 and 2, the sight mount  10  includes a generally rectangular base  10   a  having transverse spaced slots  10   b  on its upper surface, and V-shaped dovetail side rails  10   c  along the upper side edges of the base  10   a , which together form a sight base which is much the same as that of the rifle  12 . The sight mount  10  further includes three transverse threaded bores  10   d , through which bolts (not shown) are passed through the transverse slots  12   b  of the rifle sight base. The bolts serve to locate the sight mount  10  on the sight base  12   a  and secure the sight mount  10  against longitudinal displacement caused by recoil of the rifle. The bolts also serve to clamp the sight mount  10  to the V-shaped rails  12   c  of the sight base  12   a . In this latter regard, the sight mount  10  includes inwardly directed V-shaped rails  12   e  (FIG.  2 ), which engage with the V-shaped rails of the sight base  12   a.    
     Referring particularly to FIG. 2, the sight mount  10  further includes an integral rear sight platform  10   f  which extends horizontally from the rear of the base  10   a , and a pair of upwardly extending integral protective ears  10   g  and  10   h , the function of which is described below. Protective ears  10   g  and  10   h  are connected by an integral, concavely curved ramp  10   i , which curves upwardly from the rearmost one of the transverse slots  10   b  to approximately half the height of ears  10   g  and  10   h . The sight platform  10   f  further includes a vertical bore  10   j  and an intersecting, transverse rectangular bore  10   l.    
     The sight platform  10   f  supports a rear iron sight assembly  14  (FIG.  2 ). Sight assembly  14  includes a sight fixture  16  having spaced left and right sidewalls  16   a  and  16   b , a horizontal floor  16   c , and a vertical threaded shaft  16   d . The sight assembly  14  further includes a windage knob  18  and an elevation knob  20 . Windage knob  18  is secured to the outside surface of the right sidewall  16   b  by means of a threaded screw  22  and a roll pin (not shown). The screw  22  passes through both sidewalls  16   a  and  16   b  from the outside of left sidewall  16   a  and also passes through a threaded bore  24   a  formed in a dual aperture iron sight  24  which is positioned between the sidewalls  16   a  and  16   b . A helical spring  26  and a ball bearing  28  are located in a bore (not shown) in the face of windage knob  18 . The ball bearing  28  is urged by spring  26  against detents  16   e  which are formed in a circular array in the outside surface of right sidewall  16   b . With this arrangement the windage knob  18  provides incremental adjustment of the position of the iron sight  24 . 
     The threaded shaft  16   d  of the sight assembly passes through the bore  10   j  of the platform  10   f  and is retained in place by a roll pin (not shown) which passes through a small bore  10   k  in the side of platform  10   f  and through a vertical slot  16   e  in the shaft  16   d . Elevation knob  20  is engaged with the threaded shaft  16   d  and positioned in the rectangular bore  10   l . Elevation knob  20  includes an interior guide ring and ball-and-detent stops (not shown) which allow the elevation knob  20  to raise and lower the sight assembly  16  in discrete increments. 
     The iron sight  24  includes a long range aperture  24   b  and a short range aperture  24   c . The sight  24  is rotatable about the screw  22 . A flat spring  30 , which is set into a rectangular recess (not shown) in the surface of floor  16   d , functions to maintain the iron sight  24  with either the long range aperture  24   d  or the short range aperture  24   c  in the upright position. 
     The sight assembly  14  further includes a helical spring  32  and a ball bearing  34 , which are set into a bore  16   g  that extends horizontally and longitudinally into the floor  16   c  where floor  16   c  intersects with left sidewall  16   a . The function of helical spring  32  and ball bearing  34  is to urge the sight assembly  16  against the rear of left protective ear  10   h , and thereby maintain optimum accuracy of the sight assembly  16 . In this regard, it will be seen that the elevation knob  20  and the threaded shaft  16   d  operate to raise and lower the assembly  16 , but do not precisely locate the assembly against small lateral displacements. The ball  34  and spring  32  serve to so locate the assembly against such lateral displacements. 
     FIGS. 5 through 7 illustrate the sight mount  10  the present invention as it is used support a conventional electronic optical sight  36 . It will be seen that the sight  36  includes dovetail mounts  36   a  which allow it to be secured to the sight mount  10  in the manner described above. 
     In particular, FIGS. 6 and 7 illustrate a principal advantage of the present invention. In FIGS. 6 and 7, a desired target is indicated by crossed lines  38  which are shown in the view of the sight  36 . That is, it should be understood that the crossed lines  38  represent a desired target as seen through the sight  36 , and are not crosshairs as are typically seen through a conventional telescopic sight. The actual aimpoint of the properly sighted rifle and sight  36  is illustrated by an aimpoint  40 , which is shown centered on the target represented by the crossed lines  38  and which is typically presented as a red, electronically generated “red dot” in the view of the sight  36 . It should also be understood, in connection with the further description below, that one of the features of modern electronic sights is that the aimpoint  40  remains accurately located on the target even though the user&#39;s angle of vision into the sight  36  may vary somewhat. 
     Thus, FIGS. 6 and 7 represent the view as seen by a user from two different angles. FIG. 6 represents the view as seen when the user is looking over the short range iron sight aperture  24   c  and also over a front sight post  42  of the rifle  12 . That is, the user is viewing the sight from a slightly elevated position behind the sight  36 . 
     In FIG. 7, the user is viewing the target from a lower angle, and is aligning the iron sight aperture  24  and the front sight post  42  on the target  38 , and which results in the aimpoint  40  of the sight  36  also being centered on the target  38 . 
     It will be seen that in both views represented by FIGS. 6 and 7, aimpoint  40  of the electronic sight is centered on the target  38 . 
     Thus, the user can use the sight mount  10  of the present invention in two alternate modes. In FIG. 6 the user is aiming at target  38  using only the aimpoint  40  of the electronic sight  36 , without using the iron sights. This is more appropriate, for example, in combat situations requiring quick sighting of the rifle. In FIG. 7, the user is using the iron sights together with the electronic sight to target the rifle. This mode might be used where increased accuracy is being sought, and where speed is not important. More importantly, however, this latter mode would be used where the electronic sight  36  has become nonfunctional, as for example where battery failure or other electronic failure has resulted in the aimpoint of the electronic sight no longer being visible. In such an event the iron sights can be used alone, sighting through the optical lenses of the nonfunctioning electronic sight, without first having to remove the electronic sight. 
     It will also be recognized that the electronic sight  36  can also be readily removed from the rifle to permit the iron sights to be used alone in their conventional manner. In such a mode it will be noted that the iron sight assembly  14  is protected from impacts and other abuses by the protective ears  10   g  and  10   h , and also by the curved ramp  10  which serves to protected against snagging of the rifle in brush or other foreign objects. 
     The foregoing description of one or more preferred embodiments of the present invention is presented for purposes of illustration and explanation, and is not intended to be exhaustive or to limit the invention to the precise form disclosed. Various modifications, alterations, and substitutions may be possible in light of the foregoing description. Accordingly, it is intended that the scope of the invention be defined by the following claims.