Abstract:
Rifle scope turrets with spiral cam mechanisms include a scope body, a movable optical element defining an optical axis enclosed by the scope body, and a turret having a screw operably connected to the optical element for adjusting the optical axis in response to rotation of the screw. The turret has a spiral cam mechanism engaged thereto. The turret defines first and second stop surfaces positioned for engagement by the spiral cam to limit rotation of the turn The first stop surface defines a zero position of the screw and the movable optical element. The second stop surface defines a maximum point of displacement of the screw and the moveable optical element. The stop surfaces may be defined by a spiral cam groove in the indexing portion of the turret. The groove may overlap itself at least partially. The turret may be an elevation turret or a windage turret.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation patent application of U.S. patent application Ser. No. 14/537,506 filed Nov. 10, 2014, which is a continuation patent application of U.S. patent application Ser. No. 13/450,005 filed Apr. 18, 2012, now U.S. Pat. No. 8,919,026; the disclosure of the above recited applications is hereby incorporated by reference herein in its entirety for all purposes. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to the field of optic sighting devices. More particularly, the present invention relates to devices and methods for conveniently adjusting such optics. 
       BACKGROUND 
       [0003]    A turret is one of two controls on the outside center part of a rifle scope body. Turrets are marked in increments and are used to adjust elevation and windage for points of impact change. Conventional turrets have markings on them that indicate how many clicks of adjustment have been dialed in on the turret, or an angular deviation, or a distance compensation for a given cartridge. A click is one tactile adjustment increment on the windage or elevation turret of a scope. 
         [0004]    In order to achieve accurate sighting of objects at greater distances, the downward acceleration on the projectile imparted by gravity is of significance. The effect of gravity on a projectile in flight is often referred to as bullet drop because it causes the bullet to drop from the shooter&#39;s line of sight. For accuracy at longer distances, the sighting components of a gun must compensate for the effect of bullet drop. An adjustment to the angular position of the rifle scope relative to the rifle barrel is made using the elevation turret to compensate for bullet drop. 
         [0005]    Similarly, any horizontal forces imparted on the projectile, such as wind, is of significance. The effect of wind on a projectile in flight is often referred to as drift because it causes the bullet to drift right or left from the shooter&#39;s line of sight. For accuracy at longer distances, the sighting components of a gun must compensate for the effect of drift. An adjustment to the angular position of the rifle scope relative to the axis of the rifle barrel is made using the windage turret to compensate for drift. 
         [0006]    Conventional turrets allow for multiple rotations in order to enable the scope to compensate for longer-range targets or environmental conditions such as wind. Unfortunately, conventional turrets typically omit at least one of the following functions: adjustment stops that prevent adjustment of the elevation and windage turrets beyond preset amounts, rotation indicator/counter, or turret locking. As a result, users of conventional turrets may lose track of how many rotations are dialed in if they do not carefully count the number of rotations both while dialing away from the zero point and when dialing towards the zero point even when the turret&#39;s markings are visible. Furthermore, turrets can be easily bumped, and in dark conditions where it may be difficult to see the turret markings, the user may not realize the turrets have been inadvertently adjusted if the turret lacks a locking mechanism. 
         [0007]    Another difficulty with existing rifle scopes is that certain operating conditions require the user to remember both how many clicks and the direction of rotation needed to return the elevation turret to its zero point from a different setting. When light conditions are poor, such as at twilight, night, or in darkened rooms of buildings, or if it is difficult for the user to hear or feel the clicks, it is very easy for the user to lose track of what adjustment is needed to return to the zero point. Under such conditions, the markings may not be sufficiently visible and the absence of a tactile rotation indicator is keenly felt. This is particularly significant for police and military users of firearms, who in the course of their duties may very likely be confronted with a threat under poor lighting conditions. In addition, hunters may hunt at twilight or in deep shade. 
         [0008]    Because of the need for compact rifle scope components, markings are necessarily small, making them difficult to read under borderline conditions. While this may be a concern when making fine adjustments, it is of greater concern when a user must make large changes involving several revolutions of a knob, which may lead to an error in the number of revolutions made. 
         [0009]    Therefore, a need exists for a new and improved rifle scope with adjustment stops that prevents adjustment of the elevation and windage turrets beyond preset amounts. There is also a need for visual and tactile indication of how many rotations have been dialed in on a turret. Finally, there is a need for a turret locking mechanism so the user can be assured that the turret is still in its last used position. In this regard, the various embodiments substantially fulfill at least some of these needs. In this respect, the spiral cam mechanism according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in doing so provides an apparatus primarily developed for the purpose of preventing adjustment of a turret beyond a preset amount, giving the user an indication of how many rotations have been dialed on the turret, and giving the user the ability to lock the turret. 
       SUMMARY OF THE INVENTION 
       [0010]    One embodiment of the present invention provides an improved rifle scope with adjustment stops, rotation indicator, and locking mechanism, and overcomes the above-mentioned disadvantages and drawbacks of the prior art. 
         [0011]    To attain this, one embodiment of the present invention essentially comprises a scope body, a movable optical element defining an optical axis enclosed by the scope body, and a turret having a screw operably connected to the optical element for adjusting the optical axis in response to rotation of the screw. The turret has a spiral cam mechanism engaged thereto. The turret defines first and second stop surfaces positioned for engagement by the spiral cam to limit rotation of the turret. The first stop surface defines a zero position of the screw and the movable optical element. The second stop surface defines a maximum point of displacement of the screw and the moveable optical element. The stop surfaces may be defined by a spiral cam groove in the indexing portion of the turret. The spiral cam groove may overlap itself at least partially. The turret may be an elevation turret or a windage turret. 
         [0012]    There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood and in order that the present contribution to the art may be better appreciated. 
         [0013]    It will be understood by those skilled in the art that one or more aspects of this invention can meet certain objectives, while one or more other aspects can lead to certain other objectives. Other objects, features, benefits and advantages of the present invention will be apparent in this summary and descriptions of the disclosed embodiment, and will be readily apparent to those skilled in the art. Such objects, features, benefits and advantages will be apparent from the above as taken in conjunction with the accompanying figures and all reasonable inferences to be drawn therefrom. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  is a side view of an embodiment of the rifle scope with adjustment stops. 
           [0015]      FIG. 2  is a top perspective exploded view of an elevation turret screw subassembly. 
           [0016]      FIG. 3  is a top perspective exploded view of the elevation turret screw subassembly and turret housing. 
           [0017]      FIG. 4  is a top perspective view of an elevation turret chassis and elevation indicator. 
           [0018]      FIG. 5A  is a top perspective view of an elevation cam disc. 
           [0019]      FIG. 5B  is a bottom perspective view of the elevation cam disc. 
           [0020]      FIG. 6  is a top view of the elevation cam disc inserted into the elevation turret chassis with the elevation cam disc rendered partially transparent. 
           [0021]      FIG. 7A  is a top perspective exploded view of the elevation turret chassis subassembly. 
           [0022]      FIG. 7B  is a side sectional view of the elevation turret chassis subassembly of  FIG. 8A  taken along the line  7 B- 7 B. 
           [0023]      FIG. 8A  is a top perspective exploded view of the elevation turret chassis subassembly, elevation turret screw subassembly, and turret housing. 
           [0024]      FIG. 8B  is a side sectional view of the elevation turret chassis subassembly, elevation turret screw subassembly, and turret housing. 
           [0025]      FIG. 9A  is a top perspective exploded view of an elevation micro adjuster and elevation outer knob. 
           [0026]      FIG. 9B  is a side sectional view of the elevation micro adjuster, elevation outer knob, elevation turret chassis subassembly, and elevation turret screw subassembly of  FIG. 1  taken along the line  9 B- 9 B. 
           [0027]      FIG. 10  is a top perspective view of a windage turret chassis. 
           [0028]      FIG. 11  is a bottom perspective view of the windage cam disc of  FIG. 10 . 
           [0029]      FIG. 12  is a side sectional view of the windage turret of  FIG. 3  taken along the line  12 - 12 . 
           [0030]      FIG. 13  is a side sectional view of the rifle scope with adjustment stops of  FIG. 1  taken along the line  13 - 13 . 
           [0031]      FIG. 14A  is a rear view of the rifle scope with adjustment stops of  FIG. 1  with the elevation turret in the locked position. 
           [0032]      FIG. 14B  is a rear view of the rifle scope with adjustment stops of  FIG. 1  with the elevation turret in the unlocked position. 
           [0033]      FIG. 15A  is a rear view of the rifle scope with adjustment stops of  FIG. 1  with the elevation turret having made one rotation. 
           [0034]      FIG. 15B  is a rear view of the rifle scope with adjustment stops of  FIG. 1  with the elevation turret having made two rotations. 
       
    
    
     DETAILED DESCRIPTION 
       [0035]    An embodiment of the rifle scope with spiral cam mechanism is shown and generally designated by the reference numeral  10 . 
         [0036]      FIG. 1  illustrates one embodiment of an improved sighting device, such as a rifle scope with spiral cam mechanism  10 . More particularly, the rifle scope or a sighting device  10  has a body  12 , in the embodiment shown, a scope body, that encloses a movable optical element  248  (shown in  FIG. 13 ), which is an erector tube. The scope body is an elongate tube having a larger opening at its front  14  and a smaller opening at its rear  16 . An eyepiece  18  is attached to the rear of the scope body, and an objective lens  20  is attached to the front of the scope body. The center axis of the movable optical element defines the optical axis  506  of the rifle scope. 
         [0037]    An elevation turret  22  and a windage turret  24  are two dials on the outside center part of the scope body  12 . They are marked in increments by indicia  34  on their perimeters  30  and  32  and are used to adjust the elevation and windage of the movable optical element  248  for points of impact change. These turrets protrude from the turret housing  36 . The turrets are arranged so that the elevation turret rotation axis  26  is perpendicular to the windage turret rotation axis  28 . Indicia typically include tick marks, each corresponding to a click, and larger tick marks at selected intervals, as well as numerals indicating angle of adjustment or distance for bullet drop compensation. 
         [0038]    The movable optical element  248  is adjusted by rotating the turrets one or more clicks. A click is one tactile adjustment increment on the windage or elevation turret of the rifle scope, each of which corresponds to one of the indicia  34 . In one embodiment, one click changes the scope&#39;s point of impact by 0.1 mrad. 
         [0039]      FIG. 2  illustrates the improved turret screw subassembly  88 . More particularly, the turret screw subassembly consists of a turret screw  38 , a turret screw base  60 , a friction pad  86 , and various fasteners. The turret screw is a cylindrical body made of brass in one embodiment. The top  40  of the turret screw defines a slot  48 , and two opposing cam slots  46  run from the top part way down the side  44 . Two 0-ring grooves  50  and  52  are on the side located below the cam slots. The bottom  42  of the turret screw has a reduced radius portion  56  that defines a ring slot  54 . The ring slot  54  receives a retaining ring  84 , and a bore  304  in the bottom  42  receives the shaft  306  of the friction pad  86 . The side of the turret screw immediately below the 0-ring groove  52  and above the ring slot  54  is a threaded portion  58 . In one embodiment, the slot  48  is shaped to receive a straight blade screwdriver, but could be shaped to receive a hex key or any other suitable type of driver. 
         [0040]    The turret screw base  60  is a disc-shaped body made of brass in one embodiment. A cylindrical collar  66  rises from the center of the top  62  of the turret screw base. The collar has a turret screw bore  68  with threads  70 . The exterior of the collar defines a set screw V-groove  78  above the top of the turret screw base, an 0-ring groove  76  above the set screw V-groove, an 0-ring groove  74  above the 0-ring groove  76 , and a ring slot  72  above the 0-ring groove  74 . The turret screw base has three mount holes  82  with smooth sides and a shoulder that receive screws  80 . 
         [0041]      FIG. 3  illustrates the improved turret screw subassembly  88  and turret housing  36 . More particularly, the turret screw subassembly  88  is shown assembled and in the process of being mounted on the turret housing  36 . The top  92  of the turret housing defines a recess  94 . Three mount holes  96  with threads  98  and a smooth central bore  508  are defined in the top of the turret housing within the recess. 
         [0042]    The threads  70  of the turret screw bore  68  are fine such that the turret screw bore may receive the threads  58  on the turret screw  38 . The retaining ring  84  limits upward travel of the turret screw so that the turret screw cannot be inadvertently removed from the turret screw bore. 
         [0043]    When the turret screw subassembly  88  is mounted on the turret housing  36 , screws  80  are inserted into the mount holes  82  and protrude from the bottom  64  of the turret screw base  60 . The screws are then screwed into the mount holes  96  in the turret housing to mount the turret screw base to the turret housing. Subsequently, the turret screw base remains in a fixed position with respect to the scope body  12  when the elevation turret  22  is rotated. This essentially makes the turret screw base functionally unitary with the scope body, and the turret screw base is not intended to be removed or adjusted by the user. The smooth central bore  508  in the top of the turret housing permits passage of the friction pad  86  and the bottom  42  of the turret screw into the scope body. 
         [0044]      FIG. 4  illustrates the improved elevation turret chassis  100 . More particularly, the top  110  of the elevation turret chassis has an interior perimeter  102  with a relief cut  240  adjacent to the floor  264 , a toothed surface  108  above the relief cut, a lower click groove  106  above the toothed surface, and an upper click groove  104  above the lower click groove. The relief cut is for the tool that cuts the toothed surface. The floor defines a smooth central bore  120  and a slot  122 . The smooth central bore permits passage of the friction pad  86  and the bottom  42  of the turret screw through the turret chassis. 
         [0045]    The exterior perimeter  112  of the turret chassis  100  defines an 0-ring groove  244 . Near the bottom  116  of the turret chassis, the exterior perimeter widens to define a shoulder  114 . Three holes  118  with threads  158  communicate from the exterior perimeter through the turret chassis to the smooth bore  120 . In one embodiment, the turret chassis is made of steel. 
         [0046]    The slot  122  in the floor  264  of the turret chassis  100  communicates with a hole  124  in the exterior perimeter  112  of the turret chassis. The hole  124  receives a rotation indicator, which in this embodiment is an elevation indicator  136 . The rear  140  of the elevation indicator defines a cam pin hole  154 . The front  138  of the elevation indicator has two stripes  148  and  150  and an 0-ring groove  152 . The stripe  148  divides a first position  142  from a second position  144 . The stripe  150  divides a second position  144  from a third position  146 . In one embodiment, the elevation indicator is made of painted black steel, and the stripes are white lines that do not glow, but which could be luminous in an alternative embodiment. 
         [0047]    The cam pin hole  154  receives the bottom  134  of a cam pin  126 . In one embodiment, the cam pin is a cylindrical body made of steel. The top  128  of the cam pin has a reduced radius portion  130  that defines a shoulder  132 . The reduced radius portion of the cam pin protrudes upward through the slot  122  above the floor  264  of the turret chassis  100 . 
         [0048]      FIGS. 5A and 5B  illustrate an improved elevation cam disc  160 . More particularly, the elevation cam disc is made of steel with a top face  162  and a bottom face  164 . The top has a reduced radius portion  166  that defines a shoulder  168  around the exterior perimeter  170  of the elevation cam disc. The top also defines three mount holes  180  with threads  182 . A reduced radius central portion  176  defines a shoulder  172  and a smooth central bore  178 . The smooth central bore permits passage of the turret screw subassembly through the elevation cam disc. 
         [0049]    A radial clicker channel  186  in the top  162  of the exterior perimeter  170  receives a clicker  188  that reciprocates in the channel, and is biased radially outward. The front, free end  190  of the clicker protrudes from the exterior perimeter. In one embodiment, the clicker has a wedge shape with a vertical vertex parallel to the axis of rotation of the turret and is made of steel. 
         [0050]    The bottom  164  of the elevation cam disc  160  is a planar surface perpendicular to the elevation turret rotation axis  26  that defines a recessed spiral channel  184 . The spiral channel terminates in a zero stop surface  198  when traveled in a clockwise direction and terminates in an end of travel stop surface  200  when traveled in a counterclockwise direction. When traveled in a counterclockwise direction, the spiral channel defines a first transition  194  and a second transition  196  when the spiral channel begins to overlap itself for the first time and second time, respectively. The spiral channel is adapted to receive the reduced radius portion  130  of the cam pin  126 . The spiral channel and the stop surfaces are integral to the elevation cam disc and are not adjustable. 
         [0051]      FIG. 6  illustrates an improved elevation cam disc  160  and improved turret chassis  100 . More particularly, the elevation cam disc is shown installed in the turret chassis. The spiral channel  184  receives the reduced radius portion  130  of the cam pin  126 . The clicker  188  protrudes from the clicker channel  186  in the exterior perimeter  170  of the elevation cam disc. A spring  202  at the rear  192  of the clicker outwardly biases the clicker such that the clicker is biased to engage with the toothed surface  108  on the interior perimeter  102  of the turret chassis. When the elevation cam disc rotates as the elevation turret  22  is rotated when changing elevation settings, the clicker travels over the toothed surface, thereby providing a rotational, resistant force and making a characteristic clicking sound. 
         [0052]    In one embodiment, the toothed surface  108  has 100 teeth, which enables 100 clicks per rotation of the elevation turret  22 . The spiral channel  184  is formed of a several arcs of constant radius that are centered on the disc center, and extend nearly to a full circle, and whose ends are joined by transition portions of the channel, so that one end of the inner arc is connected to the end of the next arc, and so on to effectively form a stepped spiral. This provides for the indicator to remain in one position for most of the rotation, and to transition only in a limited portion of turret rotation when a full turret rotation has been substantially completed. In another embodiment, the spiral may be a true spiral with the channel increasing in its radial position in proportion to its rotational position. In the most basic embodiment, the channel has its ends at different radial positions, with the channel extending more than 360 degrees, the ends being radially separated by material, and allowing a full 360 degree circle of rotation with the stop provided at each channel end. 
         [0053]    The elevation turret  22  is positioned at the indicium  34  corresponding to 0° of adjustment when the cam pin  126  is flush with the zero stop surface  198 . In one embodiment, the spiral channel  184  holds the cam pin  126  in a circular arc segment at a constant distance from the rotation axis  26  until the elevation turret has rotated 9 mrad (324°). The first transition  194  occurs as the elevation turret rotates counterclockwise from 9 mrad (324°) to 10 mrad (360°). During the first transition, the spiral channel shifts the cam pin  126  towards the exterior perimeter  170  so the spiral channel can begin overlapping itself. As the elevation turret continues its counterclockwise rotation, the spiral channel holds the cam pin  126  in a circular arc segment at a constant further distance from the rotation axis  26  until the elevation turret has rotated 19 mrad (684°). The second transition  196  occurs as the elevation turret rotates counterclockwise from 19 mrad (684°) to 20 mrad (7200°). During the second transition, the spiral channel shifts the cam pin  126  even further towards the exterior perimeter  170  so the spiral channel can overlap itself a second time. As the elevation turret continues its counterclockwise rotation, the spiral channel holds the cam pin  126  in a circular arc segment at a constant even further distance from the central bore  178  until the elevation turret has rotated 28.5 mrad (1026°). At that time, the cam pin is flush with the end of travel stop surface  200 , and further counterclockwise rotation of the elevation turret and elevation adjustment are prevented. In one embodiment, the first and second transitions are angled at about 36° (10% of the rotation) to enable adequate wall thickness between the concentric circular arc segments about the rotation axis  26  of the spiral channel. The cam pin diameter determines the overall diameter of the turret. Because there are three rotations, any increase in diameter will be multiplied by three in how it affects the overall turret diameter. In the preferred embodiment, a cam pin diameter of 1.5 mm provides adequate strength while remaining small enough to keep the overall diameter of the turret from becoming too large. 
         [0054]      FIGS. 7A and 7B  illustrate an elevation turret chassis subassembly  230 . More particularly, the turret chassis subassembly is assembled by inserting a locking gear  206  into the turret chassis  100  on top of the elevation cam disc  160 . The elevation turret chassis subassembly is shown in the locked position in  FIG. 7B . 
         [0055]    The locking gear  206  has a top  208  and a bottom  210 . The top  208  defines three mount holes  216  with threads  218 . The locking gear also defines three smooth mount holes  220  and a central smooth bore  222 . The bottom  210  of the locking gear defines a toothed surface  214 . The toothed surface  214  extends downward below the bottom  210  of the locking gear to encircle the reduced radius portion  166  of the top  162  of the elevation cam disc  160  when the turret chassis subassembly is assembled. In one embodiment, the toothed surface  214  has 100 teeth to mesh precisely with the 100 teeth of the toothed surface  108  on the interior perimeter  102  of the turret chassis  100  when the elevation turret  22  is locked. 
         [0056]    Four ball bearings  226  protrude outwards from bores  232  in the exterior perimeter  212  located between the toothed surface and the top. Springs  400  behind the ball bearings outwardly bias the ball bearings such that the ball bearings are biased to engage with the upper click groove  104  and lower click groove  106  on the interior perimeter  102  of the turret chassis  100 . When the locking gear rises and lowers as the elevation turret  22  is unlocked and locked, the ball bearings travel between the lower and upper click grooves, thereby providing a vertical, resistant force and making a characteristic clicking sound. 
         [0057]    When the turret chassis subassembly  230  is assembled, screws  224  are inserted into the mount holes  220  and protrude from the bottom  210  of the locking gear  206 . The screws are then screwed into the mount holes  180  in the top  162  of the elevation cam disc  160  to mount the locking gear to the elevation cam disc. Subsequently, the locking gear  206  remains in a fixed rotational position with respect to the elevation cam disc when the elevation turret  22  is unlocked and rotated. The heads  234  of the screws  224  are much thinner than the depth of the mount holes  220  from the top  208  of the locking gear to the shoulders  236 . The screws  224  have shoulders  228  that contact the top  162  of the elevation cam disc  160  when the screws are secured. As a result, the locking gear  206  is free to be raised until the heads of the screws contact the shoulders  236  and to be lowered until the bottom of the locking gear contacts the top of the elevation cam disc. This vertical movement is sufficient for the toothed surface  214  of the locking gear to be raised above the toothed surface  108  of the turret chassis  100 , thereby enabling the elevation turret to be unlocked and free to rotate. 
         [0058]      FIGS. 8A and 8B  illustrate an elevation turret chassis subassembly  230 , turret screw subassembly  88 , and turret housing  36 . More particularly, the turret chassis subassembly is shown assembled and in the process of being mounted on the turret screw subassembly in  FIG. 8A  and mounted on the turret screw subassembly in  FIG. 8B . 
         [0059]    When the elevation turret chassis subassembly  230  is mounted on the turret screw subassembly  88 , the top  40  of the turret screw  38  and the collar  66  of the turret screw base  60  pass upwards through the smooth central bore  120  of the turret chassis  100 , the smooth central bore  178  of the elevation cam disc  160 , and the central smooth bore  222  of the locking gear  206 . A retaining ring  246  is received by the ring slot  72  in the collar to prevent the elevation turret chassis subassembly from being lifted off of the turret screw subassembly. Three recesses  245  in the bottom  116  of the turret chassis receive the heads of the screws  80  that protrude from the top  62  of the turret screw base  60  so the bottom  116  of the turret chassis can sit flush against the top  92  of the turret housing  36 . 
         [0060]      FIGS. 9A and 9B  illustrate an improved elevation turret  22  with the top cap  308  removed. More particularly, the outer knob  268  is inserted over the top  110  of the turret chassis  100  so that the bottom  272  of the outer knob rests against the shoulder  114  of the turret chassis. The top  270  of the outer knob defines a recess  274  with threads  276 . The top of the outer knob also defines three mount holes  280  and a smooth central bore  284 . Each of the mount holes  280  receives a screw  282 . The screws  282  are screwed into mount holes  216  in the top  208  of the locking gear  206 . The perimeter  30  of the outer knob has three holes  300  in the knurled portion  310 . The holes  300  communicate with the central bore  284 . 
         [0061]    The recess  274  of the outer knob  268  receives an elevation micro adjuster  266  when the elevation turret  22  is assembled. The micro adjuster is a disc with a smooth central bore  292  and a downward facing central shaft  286 . The shaft defines an 0-ring groove  296  immediately below the disc-shaped portion of the micro adjuster. The shaft defines a V-groove  294  immediately below the 0-ring groove, and two cam pin holes  288  immediately below the V-groove. Each of the cam pin holes receives a cam pin  290 . When the elevation turret  22  is assembled, the shaft  286  is received by the bore  284  in the outer knob  268  and by the bore  222  in the locking gear. The cam pins are received by the cam slots  46  in the turret screw  38 . 
         [0062]    The micro adjuster  266  is used to provide infinite adjustability of the point of aim instead of limiting the point of aim to coincide with turret click positions. The micro adjuster rotates such that the indicia  291  indicate how much adjustment is being made. A flat blade screwdriver is inserted into the slot  48  on the top  40  of the turret screw  38  to make the adjustment once the outer knob is disengaged from the V-groove  294  in the micro adjuster. 
         [0063]    0-rings  298 ,  256 ,  252 ,  260 ,  262 ,  258 , and  254  seal the elevation turret  22  to protect its components from the elements. 
         [0064]      FIG. 10  illustrates an improved windage turret chassis  338 . More particularly, the top  344  of the windage turret chassis has an interior perimeter  340  with a relief cut  362  adjacent to the floor  364 , a toothed surface  342  above the relief cut, a lower click groove  360  above the toothed surface, and an upper click groove  358  above the lower click groove. The floor defines a smooth central bore  366  and a slot  368 . The smooth central bore permits passage of the friction pad  478  and the bottom  468  of the turret screw  446  through the turret chassis. 
         [0065]    The exterior perimeter  346  of the turret chassis  338  defines 0-ring groove  352 . Near the bottom  350  of the turret chassis, the exterior perimeter widens to define a shoulder  348 . Three holes  354  with threads  356  communicate from the exterior perimeter through the turret chassis to the smooth bore  366 . In one embodiment, the turret chassis is made of steel. 
         [0066]    The slot  368  in the floor  364  of the turret chassis  338  receives the bottom  372  of a cam pin  370 . In one embodiment, the cam pin is a cylindrical body made of steel. The top  376  of the cam pin has a reduced radius portion  378  that defines a shoulder  374 . The reduced radius portion of the cam pin protrudes upward through the slot  368  above the floor  364  of the turret chassis  338 . 
         [0067]      FIG. 11  illustrates an improved windage cam disc  322 . More particularly, the windage cam disc is made of steel with a top  510  and a bottom  326 . The top has a reduced radius portion  514  that defines a shoulder  516  around the exterior perimeter  518  of the windage cam disc. The top also defines three mount holes  522  with threads  524 . A reduced radius central portion  502  defines a shoulder  526  and a smooth central bore  328 . The smooth central bore permits passage of the friction pad  478  and the bottom  468  of the turret screw  446  through the windage cam disc. 
         [0068]    A clicker channel  512  in the top  510  of the exterior perimeter  518  receives a clicker  334 . The front  336  of the clicker protrudes from the exterior perimeter. In one embodiment, the clicker is made of steel. 
         [0069]    The bottom  326  of the windage cam disc  322  is a planar surface perpendicular to the windage turret rotation axis  28  that defines a recessed spiral channel  324 . The spiral channel terminates in an end of travel stop surface  330  when traveled in a clockwise direction and terminates in an end of travel stop surface  332  when traveled in a counterclockwise direction. When traveled in a counterclockwise direction, the spiral channel gradually moves outwards from the bore  328  so the spiral channel can slightly overlap itself. The spiral channel is adapted to receive the reduced radius portion  130  of the cam pin  126 . The spiral channel and the stop surfaces are integral to the windage cam disc and are not adjustable. To provide a full 360° of rotation, the center points of the semi-circular ends of the channel are at the same rotational position on the disc, at different radial distances from the center of the disc. More than 360° of rotation could also be provided as described with respect to the elevation cam disc  160  above. 
         [0070]    When the windage cam disc  322  is installed in the turret chassis  338 , the spiral channel  324  receives the reduced radius portion  378  of the cam pin  370 . The clicker  334  protrudes from the clicker channel  512  in the exterior perimeter  518  of the windage cam disc. A spring  412  at the rear  410  of the clicker outwardly biases the clicker such that the clicker is biased to engage with the toothed surface  342  on the interior perimeter  340  of the turret chassis. When the windage cam disc rotates as the windage turret  24  is rotated when changing windage settings, the clicker travels over the toothed surface, thereby providing a rotational, resistant force and making a characteristic clicking sound. 
         [0071]    In one embodiment, the toothed surface  342  has 100 teeth, which enables 100 clicks per rotation of the windage turret  24 . The windage turret  24  is positioned at the indicium 90 corresponding to 0° of adjustment when the cam pin  370  is located at the midpoint  320  of the spiral channel  324 . The spiral channel holds the cam pin  126  in an arc segment at a constantly increasing distance from the rotation axis  28 . The spiral channel  324  permits one-half of a revolution either clockwise or counterclockwise from the zero point  320 , which is  5  mrad in one embodiment. At that time, the cam pin is flush with an end of travel stop surface, and further rotation of the windage turret and windage adjustment are prevented. The spiral channel  324  could be reconfigured to allow various other mrads of travel from the zero point  320 . 
         [0072]      FIG. 12  illustrates an improved windage turret  24 . More particularly, the windage turret  24  is substantially identical in construction to the elevation turret  22  except for changes to the spiral cam disc and elimination of the elevation indicator. Although the windage turret could similarly include a windage indicator and spiral cam disc with more than one revolution, in practice, one revolution of the turret has been sufficient to adjust for lateral sighting adjustments. 
         [0073]    The turret screw subassembly  528  consists of a turret screw  446 , a turret screw base  490 , a friction pad  478 , and various fasteners. The turret screw is a cylindrical body made of brass in one embodiment. The top  442  of the turret screw defines a slot  444 , and two opposing cam slots run from the top part way down the side  530 . Two 0-ring grooves  464  and  494  are on the side located below the cam slots. The bottom  468  of the turret screw has a reduced radius portion  470  that defines a ring slot  472 . The ring slot  472  receives a retaining ring  476 , and the bottom  468  receives the shaft  480  of the friction pad  478  in a bore  474 . The side of the turret screw immediately below the 0-ring groove  494  and above the ring slot  472  is a threaded portion  492 . In one embodiment, the slot  444  is shaped to receive a straight blade screwdriver. 
         [0074]    The turret screw base  490  is a disc-shaped body made of steel in one embodiment. A cylindrical collar  498  rises from the center of the top  532  of the turret screw base. The collar has a turret screw bore  533  with threads  534 . The exterior of the collar defines a set screw V-groove  458  above the top of the turret screw base, an 0-ring groove  456  above the set screw V-groove, an 0-ring groove  454  above the 0-ring groove  456 , and a ring slot  452  above the 0-ring groove  456 . The turret screw base has three mount holes  536  with smooth sides and a shoulder that receive screws  486 . 
         [0075]    The threads  534  of the turret screw bore  533  are fine such that the turret screw bore may receive the threads  492  on the turret screw  446 . The retaining ring  476  limits upward travel of the turret screw so that the turret screw cannot be inadvertently removed from the turret screw bore. 
         [0076]    A locking gear  548  is inserted into the turret chassis  338  on top of the windage cam disc  322 . The windage turret  24  is shown in the locked position in  FIG. 12 . The locking gear has a top  402  and a bottom  326 . The top  402  defines three mount holes  538  with threads  540 . The locking gear also defines three smooth mount holes  426  and a central smooth bore  500 . The bottom  326  of the locking gear defines a toothed surface  542 . The toothed surface  542  extends downward below the bottom  326  of the locking gear to encircle the reduced radius portion  514  of the top  510  of the windage cam disc  322  when the turret chassis subassembly  544  is assembled. In one embodiment, the toothed surface  542  has 100 teeth to mesh precisely with the 100 teeth of the toothed surface  342  on the interior perimeter  340  of the turret chassis  338  when the windage turret  24  is locked. 
         [0077]    Four ball bearings  404  protrude outward from bores  408  in the exterior perimeter  546  located between the toothed surface and the top. Springs  406  behind the ball bearings outwardly bias the ball bearings such that the ball bearings are biased to engage with the upper click groove  358  and lower click groove  360  on the interior perimeter  340  of the turret chassis  338 . When the locking gear rises and lowers as the windage turret  24  is unlocked and locked, the ball bearings travel between the lower and upper click grooves, thereby providing a perpendicular, resistant force with respect to the optical axis  256  and making a characteristic clicking sound. 
         [0078]    When the turret chassis subassembly  544  is assembled, screws  422  are inserted into the mount holes  426  and protrude from the bottom  326  of the locking gear  548 . The screws are then screwed into the mount holes  522  in the top  510  of the windage cam disc  322  to mount the locking gear to the windage cam disc. Subsequently, the locking gear remains in a fixed rotational position with respect to the windage cam disc when the windage turret  24  is unlocked and rotated. The heads  424  of the screws  422  are much thinner than the depth of the mount holes  426  from the top  402  of the locking gear to the shoulders  550 . The screws  422  have shoulders  428  that contact the top  510  of the windage cam disc  322  when the screws are secured. As a result, the locking gear is free to be raised until the heads of the screws contact the shoulders  550  and to be lowered until the bottom of the locking gear contacts the top of the windage cam disc. This vertical movement is sufficient for the toothed surface  542  of the locking gear to be raised above the toothed surface  342  of the turret chassis  338 , thereby enabling the windage turret to be unlocked and free to rotate. 
         [0079]    When the windage turret chassis subassembly  544  is mounted on the turret screw subassembly  528 , the top  442  of the turret screw  446  and the collar  498  of the turret screw base  490  pass upwards through the smooth central bore  366  of the turret chassis  338 , the smooth central bore  328  of the windage cam disc  322 , and the smooth central bore  500  of the locking gear  548 . A retaining ring  450  is received by the ring slot  452  in the collar to prevent the windage turret chassis subassembly from being lifted off of the turret screw subassembly. Three recesses  552  in the bottom  414  of the turret chassis receive the heads of the screws  486  that protrude from the top  532  of the turret screw base  490  so the bottom  414  of the turret chassis can sit flush against the top of the turret housing  36 . 0-rings  488  seal the screws  486  within mount holes  536 . An 0-ring groove  482  in the bottom  554  of the turret screw base receives an 0-ring  484  to seal the bottom of the turret screw base against the top of the turret housing  36 . 
         [0080]    The outer knob  380  is inserted over the top  344  of the turret chassis  338  so that the bottom  556  of the outer knob rests against the shoulder  348  of the turret chassis. The top  392  of the outer knob defines a recess  558  with threads  382 . The top of the outer knob also defines three mount holes  560  and a smooth central bore  562 . Each of the mount holes  560  receives a screw  398 . The screws  398  are screwed into mount holes  538  in the top  402  of the locking gear  548 . The perimeter  32  of the outer knob has three holes  384  in the knurled portion  312 . The holes  384  communicate with the central bore  562 . 
         [0081]    The recess  558  of the outer knob  380  receives an windage micro adjuster  388  when the windage turret  24  is assembled. The micro adjuster is a disc with a smooth central bore  390  and a downward facing central shaft  448 . The shaft defines an 0-ring groove  394  immediately below the disc-shaped portion of the micro adjuster. The shaft defines a V-groove  592  immediately below the 0-ring groove, and two cam pin holes, similar to the pin hole  288  seen in  FIG. 9B , immediately below the V-groove. Each of the cam pin holes receives a cam pin, similar to the cam pin  290  seen in  FIG. 9B . When the windage turret  24  is assembled, the shaft  448  is received by the bore  562  in the outer knob  380  and by the bore  500  in the locking gear. The cam pins are received by the cam slots in the turret screw  446 . 
         [0082]    The micro adjuster  388  is used to provide infinite adjustability of the point of aim instead of limiting the point of aim to coincide with turret click positions. Indicia on the micro adjuster rotate to indicate how much adjustment is being made. A flat blade screwdriver is inserted into the slot  444  on the top  442  of the turret screw  446  to make the adjustment once the outer knob is disengaged from the V-groove  592  in the micro adjuster. 
         [0083]    0-rings  440 ,  396 ,  460 ,  462 ,  466 ,  436 ,  484  and  488  seal the windage turret  24  to protect its components from the elements. 
         [0084]      FIGS. 13-15B  illustrate an improved rifle scope turret with spiral cam mechanism  10 . More particularly, the rifle scope  10  is shown in use.  FIGS. 14A and 14B  show the elevation turret  22  in the locked and unlocked positions, respectively. The elevation turret is unlocked by raising it parallel to the rotation axis  26 . This upward motion disengages the toothed surface  214  of the locking gear  206  from the toothed surface  108  of the turret chassis  100 . The elevation turret is then free to rotate to the extent permitted by the spiral channel  184  in the elevation cam disc  160 . Lowering the elevation turret engages the toothed surface of the locking gear  206  with the toothed surface  108  of the turret chassis. This downward motion returns the elevation turret to the locked position. 
         [0085]    When “0” on the outer knob  268  is facing the user, the cam pin  126  is resting against the zero stop surface  198 , which prevents any further downward adjustment of the turret screw  38 . Zero on the outer knob is the distance the rifle scope  10  is sighted in at when no clicks have been dialed in on the elevation turret and references the flight of the projectile. If the rifle scope is sighted in at 200 yards, it is said to have a 200 yard zero. 
         [0086]    When the elevation turret  22  is unlocked, the user rotates the elevation turret counterclockwise for longer range shots than the sight-in distance of the rifle scope  10 . Rotation of the turret adjusts the amount of the turret screw  38  that extends from the bottom of the turret. As is shown in  FIG. 13 , the turret applies a downward force in the form of elevation pressure to the moveable optical element  248  via the friction pad  86 . The windage turret  24  applies a sideways force in the form of windage pressure to the movable optical element via the friction pad  478 . These forces are balanced by a biasing spring pressure applied to the moveable optical element by a biasing spring at an angle of about 135° with respect to both the elevation pressure and the windage pressure. 
         [0087]    Once a full revolution is made on the elevation turret  22 , the elevation indicator  136  pops out from hole  124  in the exterior perimeter  112  of the turret chassis  100 . The position of the elevation indicator after one revolution is shown in  FIG. 15A , in which the first position  142 , stripe  148 , and second position  144  are visible. After a second revolution is made on the elevation turret, the elevation indicator extends further outwards radially as shown in  FIG. 15B , in which the stripe  150  and a portion of the third position  146  are newly visible. When the user dials the turret back down by rotating the turret clockwise, the indicator retracts back into the turret chassis. As a result, the indicator provides both visual and tactile indication to the user of which of the nearly three revolutions the elevation turret is on. 
         [0088]    The windage turret functions substantially identically to the elevation turret except for lacking an elevation indicator. Although the windage turret could similarly include a windage indicator, in practice, one revolution of the turret has been sufficient to adjust for lateral sighting adjustments. 
         [0089]    While multiple embodiments of the rifle scope turret with adjustment stops, rotation indicator, locking mechanism and/or multiple knobs have been described in detail, it should be apparent that modifications and variations thereto are possible, all of which fall within the true spirit and scope of the invention. With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.