Abstract:
A rugged, adjustable optical alignment device well suited for use as a pistol rear sight is adapted for use in a dovetail, as is customarily seen on the slide of an automatic pistol. The sight assembly includes a rear notch, but could just as easily include a peep aperture or other optical alignment structure. The rear sight provides an easy click-detent adjusting mechanism for horizontal translation of the notch, as well as a second click-detent mechanism for vertical translation of the structure defining the notch, thereby providing adjustments for windage and elevation. A base hingedly supports a vertical tilt member. A horizontal slide member mounted on the rear of the vertrical tilt member is horizontally translatable by adjustment of a windage adjustment screw.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS AND CLAIM TO PRIORITY 
   This application claims the benefit (under 35 U.S.C. §§ 119(e) and 120) of U.S. provisional patent application No. 60/496,990, filed Aug. 22, 2003, the entire disclosure of which is incorporated herein by reference. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to an adjustable optical device such as a pistol sight and a method for mounting and adjusting optical alignment devices such as gun sights on pistols or other firearms. 
   2. Discussion of the Prior Art 
   At present, a wide variety of optical sights are available for use on firearms such as pistols. 
   A typical handgun or pistol has optical alignment fixtures or sights including a front sight and a rear sight which are aligned with one another to form a sight picture for aligning the pistol&#39;s point of aim on a target. Prior art pistol sights are usually mounted along the top edge of the pistol. Traditional semi-automatic pistols (such as the well known Colt™ model 1911, caliber 0.45) include a grip or handle carrying a lower receiver and a trigger mechanism, with a slide member slidably supported on the lower receiver and surrounding the barrel. 
   The traditional front sight is a vertically projecting blade, post or ramp-like member mounted at the front of the slide and the rear sight is adapted for mounting to the rear of the slide using a dovetail shaped transverse protrusion that mates with a corresponding transverse dovetail shaped slot in the pistol&#39;s slide. 
   Police officers and members of the military require especially rugged sights on their weapons and so a genre of firearms and accessories adapted for “combat carry” has evolved to serve their special needs. 
   The applicant developed a fixed sight intended to provide a smooth and snag-free draw, a clear sight picture and rugged service; the applicant&#39;s fixed sight design is shown in Design Patent D447,205. Others, including gunsmith Wayne Novak, have also developed a number of designs for sights intended to provide rugged service, and such sights are often fitted in a transverse dovetailed notch having standardized dimensions known in the industry as the “Novak notch” dimensions. By “transverse” is meant in a direction at a right angle to the pistol bore and lying in a horizontal plane when the pistol is held in a standard vertically aligned grip with the bore centerline in a horizontal plane. Generally, the standard notch will slidably receive and support a dovetail-like projection that is 12.5 millimeters (mm) in fore-aft length along a planar bottom surface and tapers inwardly at a selected angle (e.g., 60 to 70 degrees) from horizontal on front and back wall surfaces; the bottom planar surface of the sight&#39;s dovetail shaped projection is preferably 3 mm in vertical height from the upper surface of the notch opening, within customary gunsmithing tolerances. 
   While the combat sights of the prior art do provide a smooth and snag-free draw, a clear sight picture and rugged service, they do not provide the adjustability many have come to enjoy when using target pistols equipped with adjustable target sights. 
   Pistol sights are often used in a variety of situations. A sight is customarily optically aligned along the axis of the bore and used to align the bore of the firearm with the target. Target sights are usually adjustable in the left and right direction for “windage” and in the up and down direction for “elevation.” Usually, a shooter will mount a sight to a firearm and then immediately “zero” the sight by a procedure of adjusting windage and elevation settings so that the sight&#39;s point of aim corresponds with the projectile&#39;s point of impact for a selected target at a desired range. 
   Traditional combat carry sights, as described above, are usually not adjustable for windage, and so shooters have turned to permanently altering the front sight post by filing it down (to raise the point of impact) or substituting a taller front sight blade (to lower the point of impact). Adjustments for windage have required the shooter to strike the side of the sight with a pin punch and hammer, to force the sight laterally in the notch, a procedure which does not permit fine adjustment. 
   If a target sight is mounted to a large caliber firearm generating large recoil forces, the zero may change after firing several rounds and the sight must then be adjusted for proper zero again. Target sights are also relatively fragile, and may move out of adjustment if a pistol is dropped or struck. Both of these results present an unsatisfactory result if the firearm is to be used in life-threatening situations. 
   There has been a long felt need, then, for a method and apparatus permitting attachment and adjustment of a combat carry style rear sight or the like on a firearm such as a pistol, permitting the shooter to quickly and easily zero the sights. 
   OBJECTS AND SUMMARY OF THE INVENTION 
   Accordingly, it is a primary object of the present invention to overcome the above mentioned difficulties by providing a method and apparatus permitting the user to rigidly affix a sight onto a firearm and to permit precise and convenient sight adjustment. 
   Another object of the present invention is attaching an adjustable optical alignment device to a mount to permit a smooth and snag-free draw, a clear sight picture and rugged service. 
   The aforesaid objects are achieved individually and in combination, and it is not intended that the present invention be construed as requiring two or more of the objects to be combined unless expressly required by the claims attached hereto. 
   In accordance with the present invention, an optical aligning instrument, or sight, is adapted for use in a Novak-style dovetail, as is customarily seen on the slide of an automatic pistol. The sight assembly includes a rear notch, in the embodiments illustrated below, but could just as easily include a peep aperture or other optical alignment structure. The rear sight provides an easy click-detent adjusting mechanism for horizontal translation of the notch, as well as a second click-detent mechanism for vertical translation of the structure defining the notch, thereby providing for the customary adjustments of windage and elevation, without requiring the shooter to either file down the front sight or strike his or her pistol with a hammer and drift pin. 
   In the adjustable rear pistol sight of the present invention, the adjustable sight assembly includes a base with a downwardly-projecting dovetail-shaped member adapted to fit in the pistol&#39;s transverse dovetail slot, and the base carries a vertical tilt member hinged to rotate about an axis defined by a elevation-tilt hinge pin carried by laterally spaced bosses or vertical walls projecting up from the base. The vertical translation of the sighting notch (or other optical alignment structure) is accomplished by adjusting an elevation adjustment screw removably received in a threaded bore defined in the vertical tilt member and threadably received in the base. The elevation adjustment screw has a flanged head adapted to engage or cooperate with a detent mechanism to provide positive click adjustment to give the user feedback, and to maintain the zero setting during rugged use of the firearm. The vertical tilt member is biased upwardly, away from the base by a coil spring or other elastic force-supplying structure (referred to broadly as a “spring”). 
   In the adjustable sight assembly of the exemplary embodiment, the vertical tilt member carries a horizontal slide which preferably includes or defines a sighting notch that is translatable in the horizontal, or windage, direction by use of a click-detent windage adjustment screw. The windage adjustment screw also has a flanged head adapted to engage or cooperate with a detent mechanism provide positive click adjustment and give the user feedback, and to maintain the zero setting during rugged use of the firearm. The horizontal slide member has a cantilevered, or forwardly-projecting, cylindrical member carried by a connecting support segment affixed to a vertical front wall surface, and the interior of the cylindrical segment is threaded to received and cooperate with the threaded windage adjustment screw. The windage adjustment screw moves the cylindrical segment of the horizontal slide member left and right laterally through an adjustment range provided by a rearward-facing slot defined in the vertical tilt member. The windage adjustment screw is kept in place by a threaded member or nut which is received in a circular receiving socket or aperture on the side of the vertical tilt member; the depth of the socket is substantially equal to the thickness of the nut so that the nut is sunken within the side wall to provide a flush fit. The windage adjustment screw has first and second outer diameters, with the distal end of the windage adjustment screw having a smaller diameter than the majority of the length of the elevation adjustment screw body. The smaller distal portion of the elevation adjustment screw is threadably received in the retaining nut which, being round, spins freely within the socket defined in the side of the vertical tilt member. Rotation of the windage adjustment screw causes the cylindrical member carried by the horizontal slide to move left and right freely within the vertical tilt member tunnel. A substantially rectangular slot provides clearance for the supporting steel segment which connects the horizontal slide member&#39;s cylindrical segment to the exposed rear portion of the horizontal slide, defining the sighting notch. 
   In use, the adjustable sight assembly is installed by inserting the dovetail-shaped base into the Novak-style transverse dovetail-shaped slot in a pistol slide or firearm receiver, and the gunsmith or shooter estimates an appropriate central location for the sight assembly. A base set screw is then tightened, preferably with an Allen wrench or hex key, to (at least preliminarily) fix the lateral position of the sight assembly in the slide notch. Once installed, the user may twist the elevation adjustment screw against its detent to adjust the vertical translation of the vertical tilt member, which swings through an arc about the hinge pin. The elevation adjustment of the sight is held steady by the elevation tilt bias spring, which may provide some shock-absorbent qualities in the event the pistol is dropped. 
   The user then turns the windage adjustment screw against its spring-biased detent to laterally translate the horizontal slide to adjust the lateral position of the sighting notch and the point of impact for a given point of aim. 
   The above and still further objects, features and advantages of the present invention will become apparent upon consideration of the following detailed description of a specific embodiment thereof, particularly when taken in conjunction with the accompanying drawings, wherein like reference numerals in the various figures are utilized to designate like components. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a top or overhead view, in elevation, of the adjustable sight assembly of the present invention aligned for insertion in the sight carrying notch of a pistol slide, in accordance with the method of the present invention. 
       FIG. 2  is a left side view, in elevation, of the adjustable sight assembly of  FIG. 1  inserted in the sight carrying notch of the pistol slide, in accordance with the method of the present invention. 
       FIG. 3  is an exploded perspective view of the adjustable sight assembly of  FIGS. 1 and 2 , in accordance with the present invention. 
       FIGS. 4   a  through  4   f  are six views of the adjustable sight assembly of  FIGS. 1 and 3 . 
       FIGS. 5   a  through  5   d  are detailed views of the base member of the adjustable slide assembly of  FIG. 1 , in accordance with the present invention. 
       FIGS. 6   a  through  6   d  are detailed views of the vertical tilt member for the adjustable sight assembly of  FIG. 1 , in accordance with the present invention. 
       FIGS. 7   a - 7   d  are detailed views of the horizontal slide member the adjustable sight assembly of  FIG. 1 , in accordance with the present invention. 
       FIGS. 8   a  through  8   d  are detailed views of the windage adjustment screw of the adjustable sight assembly of  FIG. 1 , in accordance with the present invention. 
       FIGS. 9   a  through  9   d  are detailed views of the elevation adjustment screw of the adjustable sight assembly of  FIG. 1 , in accordance with the present invention. 
       FIGS. 10   a  through  10   c  are detailed views of the hinge pin, an elevation tilt bias spring member and the windage adjustment spring member of the adjustable sight assembly of  FIG. 1 , in accordance with the present invention. 
       FIGS. 11   a  and  11   b  are detailed views of the windage adjustment nut of the adjustable sight assembly of  FIG. 1 , in accordance with the present invention. 
       FIG. 12  is a perspective view, in elevation, of a second embodiment of the adjustable sight assembly of the present invention. 
       FIG. 13  is a perspective view, in partial cross-section, of the adjustable sight assembly of  FIG. 12 , in accordance with the present invention. 
       FIG. 14  is an exploded view, in perspective, of the adjustable sight assembly of  FIG. 12 . 
       FIGS. 15   a  through  15   f  are detailed views of the adjustable sight assembly of  FIG. 12 . 
       FIG. 16  is an exploded view, in perspective, of the adjustable sight assembly of  FIG. 12 . 
       FIGS. 17   a  through  17   d  are detailed views of the base member for the adjustable sight assembly of  FIG. 12 . 
       FIGS. 18   a  through  18   d  are detailed views of the vertical tilt member for the adjustable sight assembly of  FIG. 12 . 
       FIGS. 19   a  through  19   d  are detailed views of the horizontal slide member of the adjustable sight assembly of  FIG. 12 . 
       FIGS. 20   a  through  20   d  are detailed views of the windage adjustment screw of the adjustable sight assembly of  FIG. 12 . 
       FIGS. 21   a  through  21   d  are detailed views of the elevation adjustment screw of the adjustable sight assembly of  FIG. 12 . 
       FIGS. 22   a  through  22   c  are detailed views of the base screw used for either of the adjustable sight assemblies shown in  FIGS. 1 through 21 . 
       FIGS. 23   a  through  23   f  illustrate the elevation tilt hinge pin, the elevation tilt bias spring, the elevation detente pin, the windage detent pin and the windage nut fastener, respectively. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   As best seen in  FIGS. 1 and 2 , a first embodiment of adjustable sight assembly  100  is aligned with Novak-style dovetail notch  32  to permit mounting sight assembly  100  on pistol slide  30 .  FIG. 2  illustrates a side view of adjustable sight assembly  100  in dovetail notch  32  on pistol slide  30  and shows the orientation of sight base  114  when received within notch  32 . 
   Referring now to  FIGS. 3-11   b , in the first embodiment of the adjustable rear pistol sight of the present invention, adjustable sight assembly  100  preferably includes a base  114  with a downwardly-projecting dovetail-shaped member adapted to fit in the pistol&#39;s transverse dovetail slot, and base  114  carries a vertical tilt member  110  hinged to rotate about an axis defined by an elevation-tilt hinge pin  126  carried by laterally spaced vertically projecting side walls or bosses on base  114 . The vertical translation of the sighting notch  130  (or any other optical alignment structure) is accomplished by adjusting an elevation adjustment screw  116  removably received in a threaded bore  115  in base  114  and aligned with a through bore in vertical tilt member  110 . Elevation adjustment screw  116  has a flanged head with radially aligned scallops or grooves  117  (best seen in  FIG. 9   b ) adapted to engage a ball detent  120  to provide positive click adjustment to give the user feedback, and to maintain the zero setting during rugged use of the firearm. 
   Vertical tilt member  110  is biased upwardly, away from base  114  by at least one (and preferably two symmetrically arranged) elevation tilt bias spring(s)  128  or other elastic force-supplying structure (referred to broadly as a “spring”). 
   In the adjustable sight assembly  100 , the vertical tilt member  110  carries a horizontal slide  112  which preferably includes a substantially planar, non-reflective rear facing surface with an opening that defines sighting notch  130 . Horizontal slide member  112  is translatable in the horizontal, or windage, direction by use of a click-detent windage adjustment screw  218 . Windage adjustment screw  118  has a flanged head with radially aligned scallops or grooves  119  (best seen in  FIG. 8   b ) adapted to engage a ball detent  122  to provide positive click adjustment and give the user feedback, and to maintain the zero setting during rugged use of the firearm. 
   As best seen in  FIGS. 3 and 7   a  through  7   c , horizontal slide member  112  has a cantilevered, or forwardly-projecting, cylindrical sleeve  132  carried by a 5 mm wide 2 mm thick connecting sleeve support segment  134  affixed to a vertical front wall surface, and the interior of the cylindrical segment is threaded to receive and cooperate with the threaded windage adjustment screw  118 . Horizontal slide cylindrical sleeve  132  preferably defines a through-bore with a radius of 2.5 mm threaded with M3×0.35 threads; the outer cylindrical wall preferably has a radius of 2.5 mm and the central axis of the sleeve is 2.75 mm above the planar bottom surface of the body of the horizontal slide  112 . 
   Windage adjustment screw  118  moves the horizontal slide cylindrical sleeve  132  left and right laterally through an adjustment range constrained by a rearward-facing slot  136  defined in vertical tilt member  110 . Vertical tilt member slot  136  is 2 mm tall and 13.5 mm wide and opens on the right side of the body of vertical tilt member  110  to be in communication with a transverse bore opening to the right side of the tilt member body and slidably receive horizontal slide sleeve  132  within bore  138 , along with windage bias spring  140 , as best seen in  FIGS. 3 and 6   a - 6   c.    
   Windage adjustment screw  118  is kept in place by a threaded member or nut  124  which is received in a circular receiving socket or aperture on the side of the vertical tilt member; the depth of the socket is approximately 1.5 mm, substantially equal to the thickness of the nut so that the nut is sunken within the left side wall to provide a flush fit. The windage adjustment screw is threadably received in the retaining nut  124  which, being round, spins freely within the socket defined in the side of the vertical tilt member. Nut  124  is preferably crimped or bonded to permanently hold windage adjustment screw  118 . As noted above, rotation of windage adjustment screw  218  causes horizontal slide cylindrical sleeve  132  to move left and right freely within the vertical tilt member tunnel or bore  138 . Vertical tilt member slot  236  provides adequate clearance for the supporting steel segment  234  connecting the horizontal slide sleeve  234  to the exposed rear portion of the horizontal slide  212 . 
   In use, the adjustable sight assembly  100  is installed by inserting the dovetail-shaped base  114  into the transverse dovetailed slot  32  in pistol slide  30 , and the gunsmith or shooter estimates an appropriate central location for sight assembly  100 , preferably centered over the pistol&#39;s bore axis or centerline  34 . Base screw(s)  128  are then tightened, preferably with an Allen wrench or hex key, to (at least preliminarily) fix the lateral position of the sight assembly  100  in the slide notch  32 . Once installed, the user may twist elevation adjustment screw  116  against its detent to adjust the vertical translation of vertical tilt member  110  which swings through an arc about hinge pin  126 . The elevation adjustment of the sight is held steady by bias spring(s)  128 , which may provide some shock-absorbent qualities in the event the pistol is dropped. 
   The user may then turns windage adjustment screw  118  against its spring-biased detent to laterally translate the horizontal slide member  112  to adjust the point of aim of the pistol. 
   All of the components of sight assembly  100  are preferably fabricated from tool steel or materials customarily employed in gunmaking, and are preferably machined using spark erosion methods or wire electro-discharge machining (wire EDM) methods. In the preferred embodiment of sight assembly  100 , as shown in  FIGS. 1-11 , hinge pin  126  is received within coaxially aligned transverse hinge pin receiving bores, where the base&#39;s first sidewall bore and second sidewall bore are necessarily coaxially aligned and the tilt member&#39;s pin-receiving bore axis, when aligned with said base&#39;s sidewall bores, are all within three to five millimeters (3-5 mm) of the base&#39;s front edge. 
   Referring now to  FIGS. 12-23   f , in a second embodiment of the adjustable rear pistol sight of the present invention, adjustable sight assembly  200  preferably includes a base  214  with a downwardly-projecting dovetail-shaped member adapted to fit in the pistol&#39;s transverse dovetail slot, and base  214  carries a vertical tilt member  210  hinged to rotate about an axis defined by an elevation-tilt hinge pin  226  carried by laterally spaced bosses base  214 . The vertical translation of the sighting notch  230  (or other optical alignment structure) is accomplished by adjusting an elevation adjustment screw removably received in a threaded bore defined in vertical tilt member  210  and threadably received the base  214 . Here again, the elevation adjustment screw  216  has a scalloped head adapted to receive a spring-biased detent pin or rod  220  to provide positive click adjustment to give the user feedback, and to maintain the zero setting during rugged use of the firearm. Vertical tilt member  210  is biased upwardly, away from base  214  by an elevation tilt bias spring  228  or other elastic force-supplying structure (referred to broadly as a “spring”). 
   In the adjustable sight assembly of the second embodiment  200 , the vertical tilt member  210  carries a horizontal slide  212  which preferably includes or defines sighting notch  230 ; vertical tilt member  230  is translatable in the horizontal, or windage, direction by use of a click-detent windage adjustment screw  218 . Windage adjustment screw  218  has a scalloped head which is adapted to receive a spring-biased detente pin or rod  222  to provide positive click adjustment and give the user feedback, and to maintain the zero setting during rugged use of the firearm. 
   As best seen in  FIGS. 14 ,  16  and  19   a  through  19   d , horizontal slide  212  has a cantilevered, or forwardly-projecting, cylindrical sleeve  232  carried by a 5 mm wide 2 mm thick connecting sleeve support segment  234  affixed to a vertical front wall surface, and the interior of the cylindrical segment is threaded to receive and cooperate with the threaded windage adjustment screw  218 . Horizontal slide cylindrical sleeve  232  preferably defines a through-bore with a radius of 2.5 mm threaded with M3×0.35 threads; the outer cylindrical wall preferably has a radius of 2.5 mm and the central axis of the sleeve is 2.75 mm above the planar bottom surface of the body of the horizontal slide  212 . 
   Windage adjustment screw  218  moves the horizontal slide cylindrical sleeve  234  left and right laterally through an adjustment range constrained by a rearward-facing slot  236  defined in vertical tilt member  210 . Vertical tilt member slot  236  is 2 mm tall and 13.5 mm wide and opens on the right side of the body of vertical tilt member  210  to be in communication with a transverse bore opening to the right side of the tilt member body and slidably receive horizontal slide sleeve  234  as best seen in  FIGS. 16 and 18   a - 18   d.    
   Windage adjustment screw  218  is kept in place by a threaded member or nut  224  which is received in a circular receiving socket or aperture on the side of the vertical tilt member; the depth of the socket is approximately 1.5 mm, substantially equal to the thickness of the nut so that the nut is sunken within the left side wall to provide a flush fit. The windage adjustment screw has first and second outer diameters (i.e., 3 mm and 2.5 mm), with the distal end of windage adjustment screw (opposite the head) having the smaller diameter than the majority of the length of the elevation adjustment screw body. The smaller distal portion of the elevation adjustment screw is threadably received in the retaining nut  224  which, being round, spins freely within the socket defined in the side of the vertical tilt member. As noted above, rotation of windage adjustment screw  218  causes horizontal slide cylindrical sleeve  232  to move left and right freely within the vertical tilt member tunnel or bore  238 . Vertical tilt member slot  236  provides adequate clearance for the supporting steel segment  234  connecting the horizontal slide sleeve  232  to the exposed rear portion of the horizontal slide  212 . 
   In use, the second embodiment of the adjustable sight assembly  200  is installed by inserting the dovetail-shaped base into the transverse dovetailed slot  32  in a pistol slide  30 , and the gunsmith or shooter estimates an appropriate central location for the sight assembly. Base screw  228  is then tightened, preferably with an Allen wrench or hex key, to (at least preliminarily) fix the lateral position of the sight assembly in the slide notch. Once installed, the user may twist elevation adjustment screw  216  against its biased detent rod or pin  220  to adjust the vertical translation of vertical tilt member  210  which swings through an arc about hinge pin  226 . The elevation adjustment of the sight is held steady by bias spring  228 , which may provide some shock-absorbent qualities in the event the pistol is dropped. 
   The user then turns windage adjustment screw  218  against its spring-biased detent pin or rod  222  to laterally translate the horizontal slide to adjust the point of aim of the pistol. 
   All of the components of sight assembly  200  are preferably fabricated from tool steel or materials customarily employed in gunmaking, and are preferably machined using spark erosion methods or wire electro-discharge machining (wire EDM) methods. In the preferred embodiment of sight assembly  200 , as shown in  FIGS. 12-21   d , hinge pin  226  is received within coaxially aligned transverse hinge pin receiving bores, where the base&#39;s first sidewall bore and second sidewall bore are necessarily coaxially aligned and the tilt member&#39;s pin-receiving bore axis, when aligned with said base&#39;s sidewall bores, are all within three to five millimeters (3-5 mm) of the base&#39;s front edge. 
   For either embodiment illustrated above, the adjustable sight assembly is adapted for mounting on pistols or other firearms configured to receive a dovetail projection, and provides a compact, rugged, snag free, adjustable structure including a base (e.g.,  214 ) having a front surface, where at least a lower portion of the front surface defines a substantially planar surface segment terminating in a substantially linear front edge. The base also has a substantially planar bottom surface terminating at the front edge to define a selected base front edge angle (e.g., an angle of between 60-70 degrees). The base has a first side wall projecting upwardly from the planar bottom surface and opposing a second side wall projecting upwardly from the planar bottom surface and has a substantially planar base top surface opposite the base bottom surface and the first and second side walls project upwardly from the top surface to define substantially parallel opposing side wall surfaces. The first side wall has a first bore axially aligned with and parallel to the base front edge. The second side wall has a second bore axially aligned with the base front edge and coaxially aligned with the first side wall&#39;s bore. 
   In order to provide a very compact and snag free overall structure, the first bore axis and the second bore axis defining the hinge for the vertical tilt member (e.g.,  210 ) should be very close to (e.g., within five millimeters) of the base front edge. The hinged vertical tilt member has a front edge opposite a rear edge and includes a transverse hinge bore proximate the tilt member front edge; the tilt member carries a sighting notch at the tilt member rear edge. The hinged vertical tilt member is rotatably affixed between the first base side wall and the second base side wall with the transverse hinge bore coaxially aligned with the first sidewall bore and the second sidewall bore so that a hinge pin (e.g.,  226 ) can provide a tilting motion, thereby allowing the sighting notch to move through an arc having a selected vertical sight adjustment range. 
   The tilt member sighting notch (e.g.,  130 ) is preferably substantially rectangular in shape, having substantially vertical side wall segments separated by a selected notch width (e.g., approximately three millimeters). The tilt member sighting notch is defined in a substantially planar vertical surface proximate said tilt member rear edge, and the entire planar vertical surface is substantially textured or finished with a dull or matte finish, to provide a non-reflective visual reference for framing the pistol&#39;s front sight post in the rear notch. 
   Tilt member (e.g.  110 ) carries at least one biasing spring member configured to push the vertical tilt member away from the base top surface and through the arc. The tilt member also carries at least one tilt adjustment member (such as elevation adjustment screw  116 ) configured to limit the vertical position of the vertical tilt member when biased to move through the arc. The tilt adjustment member preferably comprises a threaded fastener having a distally projecting shaft configured to engage a threaded bore in the base and terminating proximally in a flanged head, wherein the flanged head is configured to engage a click detent mechanism. The tilt member preferably carries a horizontally translatable slide member including a non-reflective surface defining the sighting notch. 
   It will be appreciated by those skilled in the art, that the present invention makes available an optical alignment instrument or sight providing reliable and stable position adjustability in two (preferably orthogonal) directions, and other combinations of these mechanisms can be envisioned which will provide the intended result, namely providing a compact, adjustable optical alignment device to a mount to permit a smooth and snag-free draw, a clear sight picture and rugged service. 
   Having described preferred embodiments of a new and improved method, it is believed that other modifications, variations and changes will be suggested to those skilled in the art in view of the teachings set forth herein. It is therefore to be understood that all such variations, modifications and changes are believed to fall within the scope of the present invention, as set forth in the following claims.