Abstract:
A gun sight including a lens through which a target may be viewed and a light source for directing a point of light toward the lens, the point of light being reflected by the lens toward the viewer. The location of the reflected point of light with respect to the viewer along both windage and elevation axis is adjustable, and elevation and windage modules for permitting the adjustments are removable from the remainder of the gun sight without disturbing the adjusted and windage elevation settings.

Description:
BACKGROUND OF THE INVENTION 
   This invention relates to gun sights which are mounted on guns for the purpose of aiding the user in aiming the gun at a target. More particularly, the invention relates to such a sight provided with means for adjusting the elevation and windage of the sight with respect to the weapon upon which it is mounted. 
   Conventionally, the means for adjusting elevation and windage of a gun sight form a permanent part of the sight. Consequently, the adjustment elements remain on the gun, along with the sight, even though the adjustment elements are rarely needed once the sight is initially adjusted. 
   BRIEF SUMMARY OF THE INVENTION 
   According to the present invention, windage and elevation adjustment is accomplished by means of modules which are removable from the sight after the adjustments have been made. 
   Since the present invention employs elevation and windage adjustment modules which are removable from the sight after the sight has been properly adjusted with respect to the gun on which it is mounted, the adjustment modules need not be carried by the gun and sight when they are not needed. The advantage of this arrangement is that once the adjustment modules are removed, the weight of the gun is reduced. In addition, the possibility of inadvertently altering the adjustments is avoided. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be described in more detail with reference to the accompanying drawings, in which: 
       FIG. 1  is a perspective view, from the front and one side, of a gun sight according to the present invention; 
       FIG. 2  is an exploded perspective view, similar to  FIG. 1 , showing the elevation and windage modules, and a mounting plate, removed from the sight; 
       FIG. 3  is a perspective view of the gun sight, from the rear and one side, with the elevation and windage modules in place on the sight; 
       FIG. 4  is a perspective view, from the rear and the other side of the gun sight, with the adjustment modules having been removed. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The invention will be described in connection with a so-called “red dot” sight. In such a sight, a lens and a light source, e.g., an LED unit, are spaced apart along the axis of the gun. The lens is partially reflective so that the target can be seen through the lens, and simultaneously the lens reflects back to the user the light emitted by the LED in the form of a red dot. 
   The gun sight chosen to illustrate the present invention, and shown in  FIGS. 1-4  includes a platform  10  carrying an inverted U-shaped lens holder  11 . Supported within lens holder  11  is a lens arrangement  12 . Preferably, the lens arrangement is of a known design including two concavo-convex lenses in face-to-face contact sandwiching between them a partial reflection film. Lens holder  11  is pivotally mounted on platform  10  by means of two pins  13  passing through the vertical walls of the lens holder and into the platform. This permits an adjustment of the red dot to be made along a vertical elevation axis by moving the lens holder about the horizontal axis defined by the two pins  13 . 
   A bracket  15  ( FIGS. 3 and 4 ), having two upstanding ears  16  is fixed to the upper surface of platform  10 . Each ear is formed with an elongated slot (not shown) and is positioned adjacent to the inner surface of one of the vertical walls of lens holder  11 . Each wall of the lens holder has a hole aligned with the elongated slot in its respective ear  16 . A locking screw  17  passes through the hole in the lens holder and the slot in the adjacent ear and is threaded into a nut  18  adjacent to the inner face of the ear. Once the elevation adjustment has been made, by tilting lens holder  11  around pivot pins  13 , the lens holder is locked in place by tightening each pair of locking screws  17  and nuts  18 . 
   Also carried by platform  10  is a light-emitting diode (LED) unit  21 . The LED emits a red point of light in the direction of lens arrangement  12 . The red light is reflected, by the partially reflective lens arrangement, back to the user. The LED unit  21  includes a housing having two lateral arms  22  each formed with a U-shaped slot  23  positioned over two internally threaded holes (not shown) in platform  10 . Each slot  23  has an inwardly projecting ledge  24  adjacent to the upper surface of platform  10 . A locking screw  25  is accommodated by each slot  23 , the shaft of the locking screw (not shown), being threaded into the respective hole in platform  10  with which slots  23  are aligned. The space between the arms of U-shaped ledge  24  is smaller than the diameter of the locking screw head  25 , so that when the locking screws are tightened, the heads of the screws press down on ledges  24  to fix the LED unit in place on platform  10 . 
   With locking screws  25  in a loosened condition, LED unit can be shifted laterally to move the red dot along a horizontal windage axis so as to perform the windage adjustment. After the adjustment has been made, screws  25  are tightened to hold the LED unit firmly in place on platform  10 . 
   Stored within the hollow interior of platform  10  are a battery and associated circuitry for operating the LED. A button  27  ( FIGS. 1 and 2 ) at the front of the platform is used to turn the LED on and off, and may also be used to vary the brightness of the light emitted by the LED. 
   Adjustment of elevation and windage are accomplished by means of an elevation module  28  and a windage module  29 , respectively. 
   The elevation module  28  (best seen in  FIG. 2 ) includes a bracket portion  30  integral with a cylindrical housing  31 . The wall of housing  31  is formed with a vertically elongated slot  32  through which a finger  33  having a rounded tip projects externally from inside the housing. Finger  33  can be moved up and down by rotating the head  34  of an adjustment screw (not shown) accommodated within housing  31 . Surrounding head  34 , on the upper circular edge of housing  31 , is a series of equally spaced-apart markings  35 . Extending diametrically across adjustment screw head  34  is a slot  36  for accommodating a screwdriver blade, or like tool, for the purpose of rotating head  34  in either direction. By rotating head  34 , finger  33  is moved up or down. Markings  35 , viewed in coordination with the position of slot  36 , provide an indication of the distance through which head  34  has been rotated, and hence the distance through which finger  33  has been moved. 
   Lens holder  11  is formed with a notch  39  adapted to accommodate finger  33 . The location of finger  33  within notch  39  causes lens holder  11  to pivot about pins  13  in response to up and down movement of finger  33 . Thus, by rotating adjustment screw head  34 , resulting in movement of finger  33  and pivotal movement of lens holder  11 , the gun sight is subjected to elevation adjustment. In other words, this movement of the lens holder changes the point on the lens arrangement  12 , in a vertical direction, from which the red dot is reflected back to the user. 
   Elevation module  28  is attached to platform  10  by means of a mounting screw  40  ( FIGS. 1 and 2 ). Mounting screw  40  passes through bracket portion  30  and threads into a hole  41  in the platform. Thus, to attach elevation module  28  to platform  10  of the gun sight, housing  31  is fit into a semi-circular cavity  42  ( FIGS. 2 and 4 ) in the platform, so that finger  33  is received within notch  39 . Mounting screw  40  is then rotated to tightly join the elevation module to the platform. To remove the elevation module, mounting screw  40  is rotated in the opposite direction to unthread it from hole  41  permitting the module to be slipped in a horizontal direction away from platform  10 . These movements of the elevation module to and from the platform  10  is indicated by the double-headed arrow  43 . 
   The windage module  29  (best seen in  FIG. 2 ) includes a central body  46  flanked by two shoulders  47 . The front edges of shoulders  47  are sculpted at  48  to mesh with similarly sculpted edges  49  at the rear face of LED unit  21 . 
   Between shoulders  47  is a lug  50  ( FIG. 2 ) having an internally threaded through hole into which a threaded adjustment rod  51  is threaded. Rod  51  extends the full distance between the two shoulders  47 , one end  52  of rod  51  being rotatably captured in one of the shoulders. The other end of rod  51  is formed with a head  53  ( FIG. 3 ) carrying a screwdriver slot  54 . A serious of equi-distantly spaced markings  58  on the respective shoulder  47  surround head  53 . 
   It will be appreciated that as threaded rod  51  is rotated, by means of a screwdriver or similar tool engaging slot  54 , lug  50  will move horizontally back and forth between shoulders  47 . The back edge of platform  10  is formed with an indentation  55  ( FIG. 4 ) within which lug  50  is accommodated when windage module  29  is mounted on platform  10 . The cooperation between lug  50  and indentation  55  prevents lug  50  from moving with respect to platform  10 . Therefore, when threaded rod  51  is rotated, the remainder of windage module  29  will be moved horizontally with respect to platform  10 , and due to the cooperation of sculpted shoulders  48  and  49 , the LED unit will be moved horizontally with respect to platform  10 . The movement of the LED unit changes the point, in a horizontal direction, on the lens arrangement  12  from which the red dot is reflected back to the user. 
   Windage module  29  is secured to LED unit  21  by means of a mounting screw  56  ( FIG. 3 ) which is threaded into an internally threaded bore  57  ( FIG. 4 ) in the LED unit. To remove the windage module, mounting screw  56  is unscrewed from bore  57 , permitting the module to be moved in a horizontal direction away from LED unit  21 . The movement of module  29  toward and away from the LED unit is indicated by the double-headed arrow  59  in  FIG. 2 . 
   To mount the sight of the present invention on a gun, the upper surface of the gun has secured to it a conventional mounting rail (not shown), such as a rail distributed by Weaver Outdoor Optics, a division of Meade Instruments Corp. Secured to the mounting rail is a mount interface plate  60  ( FIG. 2 ) provided in its corners with four short upstanding posts  61 . Plate  60  is also furnished with two internally threaded holes  62 . The bottom face of platform  10  is furnished with four holes (not shown) arranged in a rectangular pattern so that they accommodate the four posts  61  of plate  60 . When mounting the sight on the gun, it is placed upon plate  60  so that the posts  61  enter the holes in the lower face of platform  10 , and two mounting screws  63 , located within through holes in platform  10 , are rotated to thread them into holes  62  and securely attach the sight to platform  60 . 
   Once the sight is mounted on the gun, the user aims by looking through sight and bringing the red dot reflected from the lens arrangement over the target. A test shot is then fired at a target. Depending on the results of the test shot, the head of elevation adjustment screw  34  is rotated to swing lens holder  11  up or down, so as to adjust the vertical position of the red dot provided by LED unit  21  on lens arrangement  12 . Also, head  53  of adjustment rod  51  is rotated so as to slide the LED unit  21  horizontally and thereby adjust the position of the red dot on lens  12  in the windage direction. Using additional test shots and elevation and windage adjustments, the correct location of the red dot on lens  12  is achieved. At that point, locking screws  17  are tightened to secure lens holder  11  in position with respect to platform  10 , and locking screws  25  are tightened to fix the LED unit to platform  10 . Then, elevation module  28  is removed from the sight by unscrewing mounting screw  40  from hole  41 , and windage module  29  is removed by unscrewing mounting screw  56  from hole  57 . 
   One advantage of a sight according to this invention is that it may be made quite small, i.e., having a length of about two inches, and a width and height of about one inch. This makes it ideal for use on pistols as well as longer barrel weapons. 
   The invention has been shown and described in preferred form only, and by way of example, and many variations may be made in the invention which will still be comprised within its spirit. It is understood, therefore, that the invention is not limited to any specific form or embodiment except insofar as such limitations are included in the appended claims.