Abstract:
Adjustment mechanisms that may be employed for making operational adjustments to sighting mechanisms such as riflescopes, telescopes, binoculars, monoculars or other types of viewing devices. One configuration being directed to a pop-up cap that is retained and remains connected to the adjustment mechanism, the pop-up cap translating between a first position (typically the closed position) where rotation of the cap does not engage the adjustment mechanism to a second (typically the extended position) where rotation of the cap engages the adjustment mechanism.

Description:
RELATED APPLICATION DATA 
     This application claims priority to provisional application No. 60/853,106 filed Oct. 20, 2006 which is hereby incorporated by reference. 
    
    
     BACKGROUND 
     The field of the present invention generally relates to devices for actuating an adjustable feature on a sighting device such as a riflescope or spotting scope or other types of telescopic optical systems. 
     Telescopic sighting devices such as riflescopes, binoculars and telescopes may include an external adjustment mechanism or knob for actuating an inner working of the scope. For example, a riflescope is commonly used by hunters to aim their rifle at selected targets. Because bullet trajectory, wind conditions, and distance to the target can vary depending upon shooting conditions, quality riflescopes typically provide compensation for variations in these conditions by allowing a shooter to make small adjustments to the optical characteristics or the aiming of the riflescope relative to the firearm on which it is mounted. These adjustments are known as elevation and windage adjustments, and are typically accomplished by lateral movement of an adjusting member, such as a reticle located within the riflescope, as shown in U.S. Pat. No. 3,058,391 of Leupold, or pivotal movement of lenses mounted to a pivot tube within a housing of the riflescope to divert the optical path of the observed light before it reaches the reticle, as shown in U.S. Pat. Nos. 3,297,389 and 4,408,842 of Gibson. In these designs, a shooter accomplishes adjustment of windage and holdover by way of two laterally protruding adjustment knobs or adjustment screws, typically extended at right angles to each other, that are operatively connected to the adjusting member. A spring located between the housing and the adjusting member opposite the adjustment knobs biases the adjusting member against the adjustment knobs so that the adjusting member follows the movement of plunger screws of the adjustment knobs. Another external adjustment mechanism is focus. U.S. Pat. No. 6,351,907 discloses an external focus adjustment mechanism by which the position of an internal lens element is axially adjusted to change focus. 
     In these various external adjustment mechanisms, the adjustment knobs may be sealed to the housing to maintain a dry or inert gas charge within the interior of the housing to prevent fogging and condensation on internal lens surfaces. 
     It is desirable for these adjustment mechanisms or knobs to be readily accessible, and yet include some means to inhibit the adjustment from being inadvertently adjusted, such as bumping against the knob. One way of preventing such inadvertent adjustment is by providing a removable cap. The cap provides both physical protection from fouling or damage as well as physical isolation from inadvertent adjustment, but the cap must be removed in order to access the internal adjustment mechanism. Moreover, once the cap is removed, the user typically places it in a pocket or other location whereby the cap may be lost. 
     SUMMARY 
     The present invention relates to adjustment mechanisms that may be employed for making operational adjustments to sighting mechanisms such as riflescopes, telescopes, binoculars, monoculars or other types of viewing devices. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded view of an adjustment mechanism according to a preferred embodiment. 
         FIG. 2  is a cross-sectional view of the adjustment mechanism of  FIG. 1  and shown assembled in position on a riflescope, and with the cap in a closed position. 
         FIG. 3  is a cross-sectional view of the adjustment mechanism of  FIGS. 1-2  with the cap in a released position and the adjustment screw in the retracted position. 
         FIG. 4  is a cross-sectional view of the adjustment mechanism of  FIGS. 1-3  with the cap in a released position and the adjustment screw in the extended position. 
         FIG. 5  is a cross-sectional view of  FIG. 4  taken along line  5 - 5 . 
         FIG. 6  is a cross-sectional view of  FIG. 4  taken along line  6 - 6 . 
         FIG. 7  is a detailed view of the index ring element of  FIG. 1 . 
         FIG. 8  is a plan view of  FIG. 7  taken along line  8 - 8 . 
         FIG. 9  is a detailed view of the cap element of  FIG. 1 . 
         FIG. 10  is a cross-sectional view of  FIG. 9  taken along line  10 - 10 . 
         FIG. 11  is a detailed view of the adjustment flange element of  FIG. 1 . 
         FIG. 12  is a detailed view of the adjustment nut element of  FIG. 1 . 
         FIG. 13  is an exploded view of an adjustment mechanism according to another preferred embodiment. 
         FIG. 14  is a cross-sectional view of the adjustment mechanism of  FIG. 13  and shown assembled in position on a riflescope, and with the cap in a closed position. 
         FIG. 15  is a cross-sectional view of the adjustment mechanism of  FIGS. 13-14  with the cap in a released position and the adjustment screw in the retracted position. 
         FIG. 16  is an exploded view of an adjustment mechanism according to another preferred embodiment. 
         FIG. 17  is a cross-sectional view of the adjustment mechanism of  FIG. 16  shown assembled in position on a riflescope, and with the cap in a closed position. 
         FIG. 18  is a detailed view of cap element for the embodiment of  FIGS. 16-17 . 
         FIG. 19  is a cross-sectional view of the adjustment mechanism of  FIGS. 16-17  with the cap in a released position and the adjustment screw in the retracted position. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Preferred embodiments will now be described with reference to the drawings. While the preferred embodiments will be described in terms of an adjustment assembly for a riflescope or spotting scope, the adjustment mechanism may also be employed with binoculars, monoculars and other types of optical viewing or sighting mechanisms. 
       FIGS. 1-12  illustrate a first embodiment for an adjustment mechanism  30  as may be installed on a sighting mechanism.  FIGS. 1 and 2  illustrate the device  30  being installed on a riflescope  10  at a turret section  15 .  FIG. 1  is an exploded view of the adjustment mechanism  30 .  FIG. 2  illustrates the mechanism in cross-section with the adjustment screw or plunger  115  in an upward position. By rotation of the upper section of the adjustment mechanism relative to the lower section, the adjustment screw  115  is translated from the upward position as shown in  FIG. 2  to an inwardly extended position as shown in  FIG. 4 , thereby allowing adjustment of the pivoting element  12  within the riflescope  10 . 
     Each of the components of the adjustment device  30  will now be described in detail. The lower section of the device  30  includes a holder piece  130  with a lower cylindrical extension that seats within the circular opening of the outer housing of the riflescope  10 . The holder  130  is held in place by an adjustment flange  80 . The adjustment flange  80  has lower male threads  83  (as shown in  FIG. 11 ) that engage the female threads  16  of the riflescope turret section  15 . An o-ring  120  is disposed in a cavity between the holder  130 , the outer surface of the riflescope  10  and the ridge within the lower section of the adjustment flange  80  to provide a sealing surface therebetween. The holder  130  includes central opening  132 , having a somewhat rectangular shape for slidably but non-rotatably receiving the lower rectangular section  116  of the adjustment screw  115 . The threads  117  of the adjustment screw  115  engage the female threads within the adjustment nut  90  such that as the adjustment nut  90  is rotated, the adjustment screw  115  is prevented from rotating by the flat sides of the opening  132  in the holder  130 , thereby axially translating the adjustment screw  115 . 
     The adjustment nut  90  is seated against an o-ring  110 , held in place by the adjustment flange  80 . A Teflon gasket  125  is disposed on an upper surface of the holder  130  below the o-ring  110  to facilitate rotation of the adjustment nut  90  relative to the holder  130 . A click-ring  100  is connected with an inner surface of the adjustment flange  80 , disposed about the outer surface of the adjustment nut  90 . A spring  95  and cup-shaped plunger  96  are disposed within a radial aperture  99  within the adjustment nut  90 . The spring  95  urges the plunger  96  radially outward, the spring  95  comprising a means for biasing or urging the plunger  96  radially outward. A ball bearing  97  is disposed within a hole or channel within the plunger, and when installed, the ball bearing  97  is urged against the gear teeth  102  of the click-ring  100 . Thus, when the adjustment nut  90  is rotated relative to the stationary click-ring  100  and adjustment flange  80 , the user can feel and/or hear the ball  97  clicking past each gear tooth, each click then representing a desired rotational translation of the adjustment nut  90 . Thus in response to rotation of the adjustment nut  90 , the ball bearing  97  registers against the gear teeth  102  of the click-ring  100  with tactile clicks, each click indicating an incremental vertical adjustment (up or down) of the pivoting element  12  within the riflescope  10 . Further details of a tactile feedback mechanism for a riflescope are disclosed in U.S. Pat. No. 6,519,890 hereby incorporated by reference. An o-ring  105  is disposed between the adjustment flange  80  and within a groove of the engagement surface  92  of the adjustment nut  90  as a seal between the two parts for preventing passage of dirt or other contaminants therebetween. 
     The adjustment flange  80  includes a pair of lateral notches or flats  88  on opposite sides for accommodating a wrench. During assembly a wrench is employed for engaging the flats  88  to rotate the adjustment flange  80  with the lower threads  83  engaging the inner threads  16  on the riflescope turret  15  and secure the flange  80  in place. The adjustment nut  90  includes an upwardly-extending cylindrical section  92  and a radially outward-extending shoulder  91 . 
     The upper rotating section includes manually rotatable member such as an upper top cap  32 , a wave spring  38 , an index ring  40  secured by set screws  43 ,  44 ,  45  to the engagement surface  92  of the adjustment nut  90 , an o-ring  54 , a cap key  60 , and a retainer ring  56  disposed within the cap key  60 . The cap  32  serves the purpose of an actuator or knob to be grasped by the user and actuate the adjustment mechanism. The cap  32  has gripping notches  33  about its outer radial surface to facilitate grasping by the user during adjustment. The cap  32  may have an internal cavity or not depending upon the desired structure. 
     A gasket  72  is disposed within a groove  82  of the adjustment flange  80 , the groove  82  being located between the upper threads  83  and the lower threads  84 . 
     The top section, labeled as “A” in  FIG. 1 , is assembled by inserting the retainer ring  56  in the groove  66  located in an inner annular surface of cap key  60 . The retainer ring  56  then forms an inwardly-extending shoulder having a diameter smaller than the diameter of the shoulder  47  of index ring  40 . The outer diameter of the lower section of the index ring  40  is a smaller diameter that slides freely through the central portion within retainer ring  56 . The cap key  60  includes flats  64   a ,  64   b  disposed on opposite internal surfaces. The flats  64   a ,  64   b  form inward shoulder sections on opposite sides of the cap key  60  of a smaller diameter than the flange shoulder  47  on the index ring  40 . This flange shoulder  47  includes flats  48   a ,  48   b  on opposite sides thereof, corresponding to the flats  64   a ,  64   b  in the cap key  60 . When the flats  48   a ,  48   b  are aligned with the flats  64   a ,  64   b , the diameter of the flange shoulder  47  between the flats  48   a ,  48   b  is smaller than the diameter between the flats  64   a ,  64   b  and allows the flange shoulder  47  to pass by the flats  64   a ,  64   b  until the flange  47  shoulder contacts the retainer ring  56 . In this position (contacting the retainer ring  56 ), the threaded holes  43   a ,  44   a ,  45   a  are below the lower sealing surface  69  of the cap key  60 , and the index ring  40  is secured to the engagement surface  92  on the adjustment nut  90  via the set screws  43 ,  44 ,  45 . 
     The wave spring  38  is positioned between the cap  32  and the index ring  40 . The female internal threads  34  on the underside of the cap  32  threadily engage the male threads  62  on the cap key  60 . When the cap  32  is in place, the spring  38  is flexed into a compression state. In that compression state, the spring  38  puts a biasing force upward on the cap  32  and cap key  60  relative to the index ring  40 , the spring  38  comprising a means for biasing or urging the cap  32  upwardly. The o-ring  54  is disposed between the inside surface of the cap  32  and the outside surface of the cap key  60  below the threads  62  to provide a friction fit between these two elements. The cap  32  has gripping notches  33  about its outer radial surface to facilitate grasping by the user during adjustment. The o-ring  54  provides a desired friction fit for the cap  32 , such that the cap  32  will not rotate relative to the cap key  60  during normal operation of the adjustment mechanism  30 . Alternately, the cap  32  may be securely connected to the cap key  60  by some other mechanism, such as by gluing the threads. In such construction, the o-ring  54  could be eliminated. 
     The operation of the device will now be described with specific reference to  FIGS. 2-4 .  FIG. 2  illustrates the adjustment mechanism  30  in the closed position with the spring  38  in the compressed position with the lower inner threads  68  of the cap key  60  engaged onto the threads  83  of the adjustment flange  80 . The lower surface  69  of cap key  60  is engaged onto the washer  72  providing a seal against external elements. 
     In order to proceed to the adjustment state, the user grasps the top cap  32  and turns it in a counter-clockwise direction to disengage the cap key threads  68  from the flange threads  83 . Once the threads are disengaged, the spring  38  will then urge the cap section (the cap  32  and cap key  60 ) upward (relative to the index ring  40 ) until the flange  47  shoulder contacts the flats  64   a ,  64   b . The user then continues to rotate the cap  32  to position the flats  48   a ,  48   b  into alignment with the flats  64   a ,  64   b . At that point, the spring  38  continues to urge the cap  32  and cap key  60  upward until the flange shoulder  47  comes into contact with the retainer ring  56 . 
     The retainer ring  56  is made of a dissimilar material to the material of the index ring  40 . The retainer ring  56  is preferably made of plastic or other suitable sound-dampening material(s) to allow for the desired sliding contact. An example where the index ring  40  and other elements are constructed of aluminum, the retainer ring may be constructed of plastic, brass or copper. 
     Once the cap  32  has translated into the upward extended position as shown in  FIG. 3 , the cap  32  and cap key  60  combination is rotationally secured to the index ring  40  for rotation therewith by engagement of the flats  48   a ,  48   b  to the flats  64   a ,  64   b . As shown in  FIG. 3 , the adjustment screw  115  is in the upward position. By rotating the cap  32 , the index ring  40  is rotated (being engaged to the cap key  60 ), thereby rotating the adjustment nut  90 . By rotating the adjustment nut  90 , the adjustment screw  115 , being prevented from rotating itself due to the flats  116  engaging the corresponding flats  132  and the holder  130 , axially translates from the contracted position shown in  FIG. 3  to an extended position as shown in  FIG. 4 . Thus the adjustment screw  115  can be adjusted outwardly or inwardly to a desired position relative to the riflescope housing  10  via rotation of the cap section  32 . Once the adjustment screw  115  is translated to the desired position, the user presses downwardly on the cap  32 , disengaging the flats  64   a ,  64   b  from the flats  48   a ,  48   b  and then closes the cap combination  32 / 60  by screwing down the cap key threads  68  onto the threads  83  of the adjustment flange  80 , returning the unit to the closed condition as in  FIG. 1 . This disengagement serves to provide protection from accidental/unintended movement of the adjustment mechanism. 
     As shown in  FIG. 7 , the index ring  40  includes index markings  42  around its outer perimeter to assist the user in achieving the desired adjustment. 
     There are several mechanisms available for providing the spring or biasing mechanism between the index ring  40  and the cap combination  32 / 60  of this adjustment mechanism, that is, the spring or biasing mechanism comprises a means for biasing or urging the cap in a particular direction. The wave spring  38  provides a preferred spring configuration, but other types of springs, such as coil springs or leaf springs, may be employed. Another type of spring may comprise a compressible bladder disposed in the cavity between the top cap  32  and the index ring  40 . Another spring mechanism may comprise using one or more magnets or combinations of the above. For example, a pair of disk magnets (oriented similarly to the magnets  238 ,  239  shown in  FIG. 13 ) may be disposed between a top cap  232  and an index ring  240 . In one configuration employing conventional magnets (where the magnetic poles are on the top and bottom sides of the disk), a top magnet  238  is attached by gluing to the underside of the cap  232  with the north pole of the magnet facing downward and a lower magnet  239  is attached to the index ring  240  with its north pole facing upward. In this arrangement the magnets  238 ,  239  would create an opposing force urging the index ring  240  and the top cap  232  apart functioning in similar fashion to the spring  38  of the first embodiment. 
     Another preferred embodiment specifically illustrated in  FIGS. 13-15  uses a unique magnetic configuration for providing the biasing/spring mechanism between the components. The components of this embodiment are similar to those of the first embodiment of  FIGS. 1-12  and like numbered elements are identical to the first embodiment and the description of those elements will be omitted for brevity. In the alternate system  230 , a first magnet  238  is attached to the underside top surface of the top cap  232 . The cap key  260  has a somewhat different configuration from the cap key of  60  the prior embodiment. The top of the cap key  260  includes threads  262  that engage the inner threads  234  of the top cap  232 . Preferably, the cap  232  is secured permanently to the cap key  260  such as via glue between the interlocking threads, but may comprise another suitable means for ensuring desired locking thread strength such as the o-ring  54  of the first embodiment. Thus the o-ring  54  shown in  FIG. 13  is optional (depending upon the configuration) and is thus not shown in  FIGS. 14-15 . 
     The second magnet  239  is attached by glue (or other suitable attachment mechanism) in the upper cavity of the index ring  40 . The magnets  238  and  239  are disk-shaped of diametrically opposed magnetic configuration. For an adjustment mechanism for a typical riflescope, the disk magnet is approximately the size of a United States nickel coin. The preferred size is approximately 0.750 inches (1.905 cm) in diameter with a thickness of 0.095 inches (0.24 cm). Powerful grade magnets are preferred, and a suitable magnet is made from Neodymium N50 grade magnetic material that is black nickel coated. The diametrically-opposed configuration is such that the north and south poles (designated “N” and “S”) of each magnet are aligned along opposite lateral sides (of the diameter of the disk) as shown in the figures. 
     In  FIG. 14 , top cap section  232  is rotated to orient the magnets with the north pole of the lower magnet  239  adjacent to the south pole of the magnet  238 , and vice versa on the opposite side, thus the magnets attract each other, keeping the top section of the mechanism in the closed position with the bottom surface  269  of the cap key  260  engaged against the gasket  72  in a sealing arrangement. As the top section is rotated approximately 90 degrees and then to 180 degrees as shown in  FIG. 15 , the north poles of the magnets become aligned with each other (as do the south poles), thus the magnets then provide a repelling force on each other forcing the upper section away from the lower section. Once in the extended position, the interconnection mechanism between the index ring  240  and the cap key  260  are engaged (the interconnection mechanism comprises the engagement of the flats  264   a,b  on the inner surface of the cap key  260  with the flats  48   a,b  on the index ring  240 ), whereby rotation of the top cap  232  serves to adjust the position of the adjustment screw  115 . 
     In this diametric magnet configuration, the north and south poles are arranged such the north pole of the top magnet  238  is aligned to the south pole of the bottom magnet  239  when the flats  48   a ,  48   b  are aligned with flats  264   a ,  264   b . Thus, if user grasping the top cap  232  applies enough upward force to the top cap  232  to overcome the magnetic attraction force, cap section will translate to the upward extended position without having to first rotate the cap  232 , thus allowing for a quick rotary adjustment. 
     Using the desired powerful type of magnet, the attraction force is quite high and it is much easier to rotate the cap than axially translate. As the cap  232  is rotated (clockwise for example), the magnets not only exert an axial attraction force but also a rotational force. Assuming the at rest attraction state (with the north pole of magnet  239  aligned with the south poles of magnet  238  as in  FIG. 14 ) as 0°, as the cap is rotated clockwise, a restoring counter-clockwise rotational force (back to 0°) is exerted by the magnets. This restoring rotational force gradually increases until the rotational position reaches about 90° and then decreases until the rotational position reaches about 180° where the rotational force dissipates to about zero. Past 180°, the rotational force reverses and urges the rotational position clockwise toward 360°. Further, as the rotational position passes 90°, the net axial attraction force reduces to zero and then past 90° the axial force reverses to a repelling force reaching a maximum at 180°. At 180°, the flats  48   a ,  48   b  are aligned with flats  264   a ,  264   b  thereby allowing the cap section to axially translate upward (the cap being urged upward by the repelling force of the magnets) into the engage state as shown in  FIG. 15 . With the flats  264   a ,  264   b  engaged, the index ring  240  is rotated via rotation of the cap  232  to allow adjustment of the adjustment screw  115  as in the first embodiment. 
     The previous embodiments employ flats between the index ring and the cap ring to provide an interlocking mechanism. Other suitable interlocking mechanisms may be employed such as splines or gears, bayonet connector, or even a manually activated mechanism such as those used for various child-proof caps.  FIGS. 16-19  illustrate an embodiment employing one such alternate interlocking scheme. The components of this embodiment are similar to those of the prior embodiments of  FIGS. 1-12  and/or  13 - 15  and like numbered elements are identical to the prior embodiment(s) and the description of those elements will be omitted for brevity. In the alternate system  330 , a first magnet  238  is attached to the underside top surface of the top cap  232 . The cap key  360  is a somewhat different configuration from the cap key of the prior embodiments. The top of the cap key  660  includes threads  362  that engage the inner threads  334  of the top cap  332 . Preferably, the cap  332  is secured permanently to the cap key  360  such as via glue between the interlocking threads, but may comprise another suitable means for ensuring desired locking thread strength such as the o-ring  54  of the first embodiment of  FIGS. 1-12 . The cap key  360  includes radially inward extending splines or gears  361  at a lower portion thereof. These splines  361  engage corresponding splines  341  in the index ring  340 . Thus since the splines may engage at any rotational position, the cap  332  need not be rotated at the 180° alignment position as in the embodiments employing the flats. Similar to the previous embodiment, the top cap section  332  is rotated to orient the magnets with the north pole of the lower magnet  239  adjacent to the south pole of the upper magnet  238 , and vice versa on the opposite side, thus the magnets attract each other, keeping the top section of the mechanism in the closed position with the bottom surface  369  of the cap key  360  engaged against the gasket  72  in a sealing arrangement. 
     Though the spline/gear engagement mechanism of  FIGS. 16-19  is illustrated with a magnet configuration, such an engagement mechanism may be particularly suited for the spring configuration of  FIGS. 1-12 . 
     Various other spring and magnet combinations are envisioned. For example, a magnet configuration similar to the configuration of  FIGS. 13-15  or  FIGS. 16-19  except that the disk magnets  238 ,  239  are of conventional configuration with north and south poles on the top and bottom surfaces. If the two magnets are arranged with opposite poles facing each other, the magnets will attract each other no matter the radial orientation. To separate the magnets, the user applies sufficient force on the cap  232  to overcome the magnetic attraction force of the magnets and translate the upper section away from the lower section and thus allow engagement of the interlocking mechanism (such as the flats  48   a / 48   b  and  264   a / 264   b  of  FIGS. 13-15  or the splines  341  and  361  of  FIGS. 16-19 ). Upon release of the cap, the magnet attraction force returns the cap  232  to the closed position. 
     A spring mechanism may be employed in place of the magnets of the previous embodiment whereby the spring is placed in tension (rather than in compression) connected at one end to the top cap and at the bottom to the index ring. In tension, the spring urges the upper cap section downward into the closed position at all times. A suitable mechanism may be provided to allow the spring to avoid rotating when the cap is rotated. Alternately, rotation of the cap may adjust the spring tension. Other spring embodiments may include spring force adjustment by axial or rotational tensioning of the spring. 
     In yet another alternate embodiment, the springs and magnets may be entirely omitted. For example, in the embodiment of  FIGS. 1-12 , if the spring  38  was omitted there would be no biasing as between the cap combination  32 / 60  and the index ring  40 , but the user would merely manually between the contracted closed position ( FIG. 2 ) to the extended position ( FIG. 3 ). The device may be provided with a suitable mechanism to somewhat retain the cap combination  32 / 60  in the extended position such as designing the flats  48   a ,  48   b  with some friction fit within the flats  64   a ,  64   b.    
     Thus according to certain of the above-described embodiments, in the field, when windage or elevation changes (for example) are called for, the adjustment system allows the user to make windage or elevation adjustments to the sighting device without using tools or removing the scope cap(s). Rotating the captive pop-up one-half turn from its locked position enables the user to lift the cap and turn the adjustment knob for making the desired adjustments. 
     Thus preferred lens systems and ocular configurations have been shown and described. While specific embodiments and applications for an ocular have been shown and described, it will be apparent to one skilled in the art that other modifications, alternatives and variations are possible without departing from the inventive concepts set forth herein. Therefore, the invention is intended to embrace all such modifications, alternatives and variations.