Patent ID: 12209842

DETAILED DESCRIPTION

The apparatuses and methods disclosed herein will now be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the disclosure are shown. The apparatuses and methods disclosed herein may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that the disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art.

It will be appreciated by those skilled in the art that the set of features and/or capabilities may be readily adapted within the context of a standalone weapons sight, front-mount or rear-mount clip-on weapons sight, and other permutations of filed deployed optical weapons sights. Further, it will be appreciated by those skilled in the art that various combinations of features and capabilities may be incorporated into add-on modules for retrofitting existing fixed or variable weapons sights of any variety.

It will be understood that when an element or layer is referred to as being “on”, “connected to” or “coupled to” another element or layer, it can be directly on, connected or coupled to the other element or layer. Alternatively, intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly connected to” or “directly coupled to” another element or layer, there are no intervening elements or layers present.

Like numbers refer to like elements throughout. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, components, regions, and/or sections, these elements, components, regions, and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, or section from another element, component, region, or section. Thus, a first element, component, region, or section discussed below could be termed a second element, component, region, or section without departing from the disclosure.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below,” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the exemplary term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90° or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

All patents, patent applications, and non-patent literature references are incorporated herein in their entireties.

Definitions

The numerical ranges in this disclosure are approximate, and thus may include values outside of the range unless otherwise indicated. Numerical ranges include all values from and including the lower and the upper values, in increments of one unit, provided that there is a separation of at least two units between any lower value and any higher value. As an example, if a compositional, physical or other property, such as, for example, molecular weight, viscosity, etc., is from 100 to 1,000, it is intended that all individual values, such as 100, 101, 102, etc., and sub ranges, such as 100 to 144, 155 to 170, 197 to 200, etc., are expressly enumerated. For ranges containing values which are less than one or containing fractional numbers greater than one (e.g., 1.1, 1.5, etc.), one unit is considered to be 0.0001, 0.001, 0.01 or 0.1, as appropriate. For ranges containing single digit numbers less than ten (e.g., 1 to 5), one unit is typically considered to be 0.1. These are only examples of what is specifically intended, and all possible combinations of numerical values between the lowest value and the highest value enumerated, are to be considered to be expressly stated in this disclosure. Numerical ranges are provided within this disclosure for, among other things, distances from a user of a device to a target.

The term “and/or” as used in a phrase such as “A and/or B” herein is intended to include both A and B; A or B; A (alone); and B (alone). Likewise, the term “and/or” as used in a phrase such as “A, B, and/or C” is intended to encompass each of the following embodiments: A, B, and C; A, B, or C; A or C; A or B; B or C; A and C; A and B; B and C; A (alone); B (alone); and C (alone).

As used herein, an “erector sleeve” is a protrusion from the erector lens mount which engages a slot in the erector tube and/or cam tube or which serves an analogous purpose. This could be integral to the mount or detachable.

As used herein, an “erector tube” is any structure or device having an opening to receive an erector lens mount.

As used herein, a “firearm” is a portable gun, being a barreled weapon that launches one or more projectiles often driven by the action of an explosive force. As used herein, the term “firearm” includes a handgun, a long gun, a rifle, shotgun, a carbine, automatic weapons, semi-automatic weapons, a machine gun, a sub-machine gun, an automatic rifle, and an assault rifle.

As used herein, the term “viewing optic” refers to an apparatus used by a shooter or a spotter to select, identify or monitor a target. The “viewing optic” may rely on visual observation of the target, or, for example, on infrared (IR), ultraviolet (UV), radar, thermal, microwave, or magnetic imaging, radiation including X-ray, gamma ray, isotope and particle radiation, night vision, vibrational receptors including ultra-sound, sound pulse, sonar, seismic vibrations, magnetic resonance, gravitational receptors, broadcast frequencies including radio wave, television and cellular receptors, or other image of the target. The image of the target presented to the shooter by the “viewing optic” device may be unaltered, or it may be enhanced, for example, by magnification, amplification, subtraction, superimposition, filtration, stabilization, template matching, or other means. The target selected, identified or monitored by the “viewing optic” may be within the line of sight of the shooter, or tangential to the sight of the shooter, or the shooter's line of sight may be obstructed while the target acquisition device presents a focused image of the target to the shooter. The image of the target acquired by the “viewing optic” may be, for example, analog or digital, and shared, stored, archived, or transmitted within a network of one or more shooters and spotters by, for example, video, physical cable or wire, IR, radio wave, cellular connections, laser pulse, optical, 802.11b or other wireless transmission using, for example, protocols such as html, SML, SOAP, X.25, SNA, etc., Bluetooth™, Serial, USB or other suitable image distribution method. The term “viewing optic” is used interchangeably with “optic sight.”

As used herein, the term “outward scene” refers to a real world scene, including but not limited to a target.

As used herein, the term “shooter” applies to either the operator making the shot or an individual observing the shot in collaboration with the operator making the shot.

As used herein, “zeroing” refers to aligning the point of aim (what the shooter is aiming at) and the point of impact (where the bullet fired from the firearm is actually hitting) at a specific distance. In one embodiment, zeroing is the process of adjusting a rifle scope to a setting in which accurate allowance has been made for both windage and elevation for a specified range.

The disclosure relates to viewing optic turrets. In one embodiment, the disclosure relates to rifle scope turrets, and more particularly to rifle scope turrets having zero adjustment mechanisms that do not require tools to make adjustments. Certain preferred and illustrative embodiments of the disclosure are described below. The disclosure is not limited to these embodiments.

FIGS.1-2illustrate a rifle scope10, generally, in accordance with embodiments of the disclosure. The rifle scope10has a body12that encloses a movable optical element13, which is an erector tube. The scope body12is an elongate tube having a larger opening at its front14and a smaller opening at its rear16. An eyepiece18is attached to the rear of the scope body12, and an objective lens20is attached to the front of the scope body12. The center axis of the movable optical element13defines the optical axis17of the rifle scope10.

An elevation turret22and a windage turret24are two knobs in the outside center part of the scope body12. They are marked in increments by indicia34on their perimeters30and32and are used to adjust the elevation and windage of the movable optical element13for points of impact change. These knobs22,24protrude from the turret housing36. The turrets22,24are arranged so that the elevation turret rotation axis26is perpendicular to the windage turret rotation axis28. 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.

The movable optical element13is 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 scope10, each of which corresponds to one of the indicial34. In the current embodiment, one click changes the scope's point of impact by 0.1 milliradians (mrad). However, the turrets, systems and concepts disclosed herein can be used with other measures of increments. In other embodiments, the increments can be minutes of angle (MOA) increments.

Using the turrets22,24to adjust the elevation and windage of the movable optical element13adjusts the elevation and windage relative to a zero point. That zero point must be established, and, in some instances, it is even desirable to adjust the zero point. Each combination of scope, rifle, and ammunition type may have its own zero point. The zero point for each turret22,24is generally provided as a feature on the given turret. WhileFIGS.4-10illustrate exemplary turrets including a zero point adjustment subassembly500in combination with an elevation turret22, it will be appreciated that the zero point adjustment subassembly500may be used with any adjustment turret, including but not limited to a windage turret or parallax adjustment mechanisms.

FIGS.3-12illustrate exemplary embodiments of a turret22having a zero point adjustment subassembly500. Generally, a turret22includes a turret screw38, a turret chassis subassembly230, and a turret cap501. The turret screw38defines a screw axis and is operably connected to the optical element13for adjusting the optical element13in response to rotation of the screw38. The turret chassis subassembly230includes a turret chassis100and the additional components required to accomplish the elevation (or other) adjustment permitted by the turret22. Exemplary turret chassis subassemblies will be described in further detail.

The turret cap501sits over the turret chassis subassembly230and is the structure that includes the indicia34and, if provided, other visual and/or tactile features. The turret cap501has an upper surface502that defines a recess504(not shown) that is generally circular and centrally located on the turret cap501. The recess has an upper surface506that is generally flat. An opening (not shown) runs through the center of the turret cap501through which the turret screw38protrudes.

A zero point adjustment subassembly500, in accordance with embodiments described herein, includes a zero cap510that connects, directly or indirectly, with the turret screw38, and a locking mechanism to secure the zero cap510to the turret cap501. As shown in theFIGS.3-12, the zero cap510is positioned in the recess504of the turret cap501with at least one component of the locking mechanism positioned between the zero cap510and the upper surface506of the recess504.

In the representative embodiment shown inFIGS.3-5, the locking mechanism comprises a lock ring530, a cam ring540, a plurality of spring followers550, and a lock ring lock button539. The lock ring530, cam ring540and zero cap510are positioned concentrically within the recess504with the cam ring540being externally concentric with the zero cap510and the lock ring530being externally concentric with both the cam ring540and zero cap510. The zero cap510has a downward protruding stem512that engages the turret screw38. A flange542on the cam ring540sits on top of the peripheral edge514of the zero cap510and retains the zero cap510in the turret cap501. The lock ring530sits on top of a second flange544of the cam ring540and engages the turret cap501to retain the cam ring540.

The spring followers550are sandwiched between the zero cap510and the upper surface506of the recess504. The spring followers550contact the outer surface516of the downward protruding stem512. In the embodiment shown inFIG.4, the tails552of the spring followers550are shown free; however, the tails552of the spring followers550are generally secured to the underside of the zero cap510using a fastener. The fastener is not shown inFIG.5for clarity and in order to show the geometry of the spring followers550.

As shown inFIG.4, the zero point adjustment subassembly500is in its locked position. The inner surface546of the cam ring540has at least two (e.g., in the embodiment shown, three) ramped surfaces548. InFIG.4, each of the spring followers550is engaged with the thickest end of the ramped surfaces548, meaning the spring followers550are applying force to the zero cap510and prohibit the zero cap510from freely spinning. Turning the cam ring540in the counterclockwise direction (relative to the embodiment as shown inFIG.4) results in the spring followers550being aligned with the thinner ends of the ramped surfaces548. Thus, less (or no) force is exerted on the zero cap510and the zero cap510freely spins within the recess504. Rotation of the cam ring540in the clockwise direction results in the spring followers550realigning with the thickest ends of the ramped surfaces548and the zero cap510being once again locked in position.

It will be appreciated that the zero point adjustment subassembly500permits adjustment of the zero point without the use of tools. That is, a user can rotate the cam ring540and zero cap510by hand. This saves time and does not require a user to turn away from the rifle scope to make any zero point adjustments.

FIG.6illustrates a further embodiment of a zero point adjustment subassembly500′ in accordance with embodiments of the disclosure. In the embodiment shown inFIG.6, the zero cap510′ includes a lever513′ with a pivot point513a′. The lever513′ has a stem515′ that projects through an opening511′ in the zero cap510′ and connects with the turret screw38. The locking mechanism includes conical wedge521′ and a collet523′. The conical wedge521′ is positioned around the turret screw38and partially extends through the opening (not shown) of the turret cap501. The conical wedge521′ is operatively connected with the lever513′ such that actuation of the lever513′ causes vertical movement of the conical wedge521′, as described in further detail below. The collet523′ also has a central opening and sits in the recess504(not shown) of the turret cap501externally concentric with the turret screw38and conical wedge521′.

As shown inFIG.6, the zero point adjustment subassembly500′ is in the locked position. The lever513′ is flush against the upper surface of the zero cap510′. The conical wedge521′ has an increasing lower radius (wedge-like radius) and, in this locked position, the conical wedge521′ has been forced upwards by the lever513′ such that the thicker portion521a′ of the conical wedge521′ contacts the flange523a′ of the collet523′, causing the collet523′ to expand radially outward into the turret cap501and lock the zero cap510′ from freely spinning. To adjust the zero point, the lever513′ is flipped along its pivot point513a′, which lowers the conical wedge521′. With the collet523′ disengaged from the conical wedge521′, the zero cap510′ can spin freely.

It will be appreciated that the zero point adjustment subassembly500′ permits adjustment of the zero point without the use of tools. That is, a user can actuate the lever513′ and rotate the zero cap510′ by hand. This saves time and does not require a user to turn away from the rifle scope to make any zero point adjustments.

FIGS.7-9illustrate a further embodiment of a zero point adjustment subassembly500″ in accordance with embodiments of the disclosure. The zero point adjustment subassembly500″ includes the zero cap510′ and the locking mechanism520″. The locking mechanism520″ includes a brake disc527″ and a lock ring530″.

As shown inFIGS.7-8, the zero cap510′ engages the turret screw38and sits in the recess (not shown) of the turret cap501. The brake disc527″ is circular with a central opening and sits over a flange514″ of the zero cap510″ in the recess. The brake disc527″ is keyed to the turret cap501via the mating of projections527a″ on the brake disc527″ with recesses501a″ on the inside wall of the turret cap501. The brake disc527″ is therefore prohibited from rotating but is free to translate vertically. The lock ring530″ is externally concentric to the zero cap510″ and the brake disc527″ and rotatably secured with the turret cap501via a threaded engagement. As the lock ring530″ is rotated into a locked position (e.g., clockwise), its vertical translation downward applies a force to the brake disc527″. The brake disc527″ transfers that downward force to the zero cap510″ that is thereby prohibited from freely spinning. Rotation of the lock ring530″ in the opposite direction (e.g., counterclockwise) releases the force on the brake disc527″, and therefore zero cap510″, to allow the zero cap510″ to freely spin in the turret cap501.

FIGS.10-12illustrate a further embodiment of a zero point adjustment subassembly500′, which is a variation of subassembly500″, in accordance with embodiments of the disclosure. The zero point adjustment subassembly500′″ includes the zero cap510′″ and the locking mechanism520″ which is composed of the locking ring530′, a brake disc527″, and a lock ring lock button539″. The locking ring530′, brake disc527′ and zero cap510′″ are all positioned concentrically within the recess (not shown) with the brake disc527′″ being externally concentric with the zero cap510′″ and the lock ring530′″ being externally concentric with both the brake disc527′″ and the zero cap510′″. The zero cap510′ has a downward protruding stem512′″ that engages the turret screw38. A flange542on the brake disc527′ sits on top of at least a portion of the upper surface516′″ of the zero cap510′ and retains the zero cap510′″ in the turret cap501. The locking ring530′ sits on top of a flange518′ of the brake disc527′″ and engages the turret cap501. In the embodiment shown, the locking ring530′″ is in threaded engagement with the turret cap501.

As shown inFIGS.10-11, the zero cap510′″ engages the turret screw38and sits in the recess (not shown) of the turret cap501. The brake disc527′″ is circular with a central opening and sits over a flange514′″ of the zero cap510′″ in the recess. The brake disc527′″ is keyed to the turret cap501via the mating of projections527a′″ on the brake disc527′″ with recesses501a′″ on the inside wall of the turret cap501. The brake disc527′″ is therefore prohibited from rotating but is free to translate vertically. The lock ring530′″ is externally concentric to the zero cap510′″ and the brake disc527′ and rotatably secured with the turret cap501via a threaded engagement. As the lock ring530′″ is rotated into a locked position (e.g., clockwise), its vertical translation downward applies a force to the brake disc527′. The brake disc527′ transfers that downward force to the zero cap510′″ that is thereby prohibited from freely spinning. Rotation of the lock ring530′″ in the opposite direction (e.g., counterclockwise) releases the force on the brake disc527″, and therefore zero cap510′″, to allow the zero cap510′″ to freely spin in the turret cap501.

As shown inFIGS.10-12, the zero point adjustment subassembly500′ further includes a lock ring lock button539″. The lock ring lock button539′″ includes and outer portion539a′″ which, in the embodiment shown, is a portion of the turret cap501and includes a tactile element different from the surrounding portions of the turret cap501. As shown inFIGS.10-12, the lock ring lock button539′″ is in its locked position, meaning rotation of the lock ring530, and therefore zero cap510′″ is prohibited. Referring toFIG.11, the lock ring lock button539′″ is provided at least one (in the embodiment shown, two) spring-containing guide-rods539b″. Once the upper surface539c′″ of the button539′″ is below the level of the lock ring530′″, the lock ring530′″ can be freely rotated. The under surface of the lock ring530′″ will cover the button539′″ to prevent the lock ring lock button539′″ from returning to its locked position while a user is making adjustments. One will appreciate that the springs of the spring-containing guide-rods539b′″ “automatically” force the button539′″ back upward into the locked position once the user has rotated the lock ring530′″ into the rotationally locked position.

Referring toFIG.12, the turret cap501further includes a groove539d′″ and the locking ring530′″ further includes a corresponding protuberance539e′″. The groove539d′″/protuberance539e″ system limits rotation of the locking ring530′″ while the lock ring lock button539′″ is depressed. This ensures that the parts of the subassembly500′″ are captive in addition to limiting rotation. Since rotation is limited, the locking ring530′″ cannot be unthreaded and removed from the turret cap501.

It will be appreciated that the zero point adjustment subassemblies500″ and500′″ permit adjustment of the zero point without the use of tools. That is, a user can rotate the lock ring530″/530′″ and zero cap510″/510′″ by hand and similarly manipulate the other components of the subassemblies500″ and500′″ by hand. This saves time and does not require a user to turn away from the rifle scope to make any zero point adjustments.

While the zero point adjustment subassemblys500,500′,500″ and500′″ described above can be used with many different styles of chassis subassemblies, the exemplary turret chassis subassembly400illustrated inFIGS.3-12is in accordance with that disclosed in U.S. Pat. No. 8,919,026 which is incorporated herein by reference. Such an exemplary turret chassis subassembly230will now be described in further detail.

As shown inFIG.13, the turret screw38is part of a turret screw subassembly88. The turret screw subassembly consists of the turret screw38, a turret screw base60, a friction pad86, and various fasteners. The turret screw38in the embodiment shown is a cylindrical body made of brass. The top40of the turret screw38defines a slot or other feature, such as threads,40that engage the zero point adjustment subassembly500(not shown). Two opposing cam slots46run from the top part way down the side44. Two o-ring grooves50and52are on the side located below the cam slots. The bottom42of the turret screw has a reduced radius portion56that defines a ring slot54. The ring slot54receives a retaining ring84, and a bore304in the bottom receives the shaft306of the friction pad86. The side of the turret screw immediately below the o-ring groove52and above the ring slot54is a threaded portion58.

The turret screw base60is a disc-shaped body that may also be made of brass. A cylindrical collar66rises from the center to the top62of the turret screw base. The collar has a turret screw bore68with threads70. The exterior of the collar defines a set screw V-groove78above the top of the turret screw base, an o-ring groove74above the o-ring groove76, and a ring slot72above the o-ring groove74. The turret screw base60has three mount holes82with smooth sides and a shoulder that receives screws80.

The fitting of the turret screw subassembly88to the turret housing36is shown inFIG.14. The top92of the turret housing defines a recess94. Three mount holes96with threads98and a smooth central bore508are defined in the top of the turret housing within the recess. The threads70of the turret screw bore68are such that the turret screw bore may receive the threads58on the turret screw38. The retaining ring84limits upward travel of the turret screw38so that the turret screw38cannot be inadvertently removed from the turret screw bore.

When the turret screw subassembly88is mounted on the turret housing36, screws80are inserted into the mount holes82and protrude from the bottom64of the turret screw base. The screws are then screwed into the mount holes96in the turret housing. Subsequently, the turret screw base remains in a fixed position with respect to the scope body12when the elevation turret22is 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 bore508in the top of the turret housing permits passage of the friction pad86and the bottom42of the turret screw38into the scope body12.

Turning toFIG.15, the top110of the turret chassis100has an interior perimeter102with a relief cut240adjacent to the floor264, a toothed surface108above the relief cut, a lower click groove106above the toothed surface108, and an upper click groove104above the lower click groove106. The relieve cut240is for the tool that cuts the toothed surface108. The floor defines a smooth central bore120and a slot122. The smooth central bore120permits passage of the friction pad86and the bottom42of the turret screw38through the turret chassis100.

The exterior perimeter112of the turret chassis100defines an o-ring groove244. Near the bottom116of the turret chassis, the exterior perimeter widens to define a shoulder114. Three holes118with threads158communicate from the exterior perimeter through the turret chassis to the smooth bore120. In the current embodiment, the turret chassis100is made of steel.

The slot122in the floor264of the turret chassis100communicates with a hole124in the exterior perimeter112of the turret chassis100. The hole124receives an indicator, such as an elevation indicator136.

The rear140of the indicator136defines a cam pin hole154. The front138of the indicator136has two stripes148and150and an o-ring groove152. The stripe148divides a first position142from a second position144. The stripe150divides a second position144from a third position146. As shown, the elevation indicator136is made of painted black steel and the stripes are white lines that do not glow, but which could be luminous in an alternative embodiment.

The cam pin hole154receives the bottom134of a cam pin126. In the current embodiment, the cam pin is a cylindrical body made of steel. The top128of the cam pin126has a reduced radius portion130that defines a shoulder132. The reduced radius portion of the cam pin protrudes upward through the slot122above the floor264of the turret chassis100.

FIGS.16A and16Billustrate a cam disc160with a top face162and a bottom face164. The top face162has a reduced radius portion166that defines a shoulder168around the exterior perimeter170of the cam disc160. The top face162also defines three mount holes180with threads182. A reduced radius central portion176defines a shoulder172and a smooth central bore178. The smooth central bore178permits passage of the turret screw subassembly88through the cam disc160.

A radial clicker channel186in the top162of the exterior perimeter170receives a clicker188that reciprocates in the channel186, and is biased radially outward. The front, free end190of the clicker186protrudes from the exterior perimeter170. The clicker186has a wedge shape with a vertical vertex parallel to the axis of rotation of the turret and is made of steel.

The bottom164of the cam disc160is a planar surface perpendicular to the elevation turret rotation axis26that defines a recessed spiral channel184. The spiral channel184terminates in a zero stop surface198when traveled in a clockwise direction and terminates in an end of travel stop surface200when traveled in a counterclockwise direction. When traveled in a counterclockwise direction, the spiral channel184defines a first transition194and a second transition196when the spiral channel begins to overlap itself for the first time and second time, respectively. The spiral channel184is adapted to receive the reduced radius portion130of the cam pin126. The spiral channel184and the stop surfaces198,200are integral to the cam disc160and are not adjustable

FIG.17the cam disc160is shown installed in the turret chassis100. The spiral channel184receives the reduced radius portion130of the cam pin126. The clicker188protrudes from the clicker channel186in the exterior perimeter170of the cam disc160. A spring202at the rear192of the clicker188outwardly biases the clicker188such that the clicker188is biased to engage with the toothed surface108on the interior perimeter102of the turret chassis100. When the cam disc160rotates as the turret22is rotated when changing settings (e.g., elevation settings), the clicker188travels over the toothed surface108, thereby providing a rotational, resistant force and making a characteristic clicking sound.

In the embodiment shown, the toothed surface108has 100 teeth, which enables 100 clicks per rotation of the elevation turret22. The spiral channel184is 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. In an alternative 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.

The turret22is positioned at the indicium34corresponding to 0° of adjustment when the cam pin126is flush with the zero stop surface198. In an embodiment, the spiral channel184holds the cam pin126in a circular arc segment at a constant distance from the rotation axis26until the elevation turret has rotated 9 mrad (324°). The first transition194occurs as the turret22rotates counterclockwise from 9 mrad (324°) to 10 mrad (360°). During the first transition, the spiral channel184shifts the cam pin126towards the exterior perimeter170so the spiral channel184can begin overlapping itself. As the turret22continues its counterclockwise rotation, the spiral channel184holds the cam pin126in a circular arc segment at a constant further distance from the rotation axis26until the elevation turret has rotated 19 mrad (684°). The second transition196occurs as the turret22rotates counterclockwise from 19 mrad (684°) to 20 mrad) (720°). During the second transition, the spiral channel shifts the cam pin126even further towards the exterior perimeter170so the spiral channel184can overlap itself a second time. As the turret22continues its counterclockwise rotation, the spiral channel184holds the cam pin126in a circular arc segment at a constant even further distance from the central bore178until the elevation turret has rotated 28.5 mrad (1026°). At that time, the cam pin126is flush with the end of travel stop surface200, and further counterclockwise rotation of the turret22and elevation adjustment are prevented. In the embodiment shown, the first and second transitions194,196are angled at about 36° (10% of the rotation) to enable adequate wall thickness between the concentric circular arc segments about the rotation axis26of 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 an 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.

FIGS.18A and18Billustrate the complete turret chassis subassembly230. The turret chassis subassembly230is assembled by inserting a locking gear206into the turret chassis100on top of the cam disc160. The turret chassis subassembly230is shown in the locked position inFIG.15B.

The locking gear206has a top208and a bottom210. The top208defines three mount holes216with threads218. The locking gear206also defines three smooth mount holes220and a central smooth bore222. The bottom210of the locking gear206defines a toothed surface214. The toothed surface214extends downward below the bottom210of the locking gear206to encircle the reduced radius portion166of the top162of the cam disc160when the chassis subassembly230is assembled. In the current embodiment, the toothed surface214has 100 teeth to mesh precisely with the 100 teeth of the toothed surface108on the interior perimeter102of the turret chassis100when the elevation turret22is locked.

Four ball bearings226protrude outwards from bores232in the exterior perimeter212located between the toothed surface and the top. Springs400located behind the ball bearings outwardly bias the ball bearings such that the ball bearings are biased to engage with the upper click groove104and lower click groove106on the interior perimeter102of the turret chassis100. When the locking gear rises and towers as the turret22is unlocked and locked, the ball bearings226travel between the lower and upper click grooves104,106, thereby providing a vertical, resistant force and making a characteristic clicking sound.

When the turret chassis subassembly230is assembled, screws224are inserted into the mount holes220and protrude from the bottom210of the locking gear206. The screws224are then screwed into the mount holes180in the top162of the cam disc160to mount the locking gear206to the cam disc160. Subsequently, the locking gear206remains in a fixed rotational position with respect to the cam disc160when the turret22is unlocked and rotated. The heads234of the screws224are thinner than the depth of the mount holes220from the top208of the locking gear206to the shoulders236. The screws224have shoulders228that contact the top162of the cam disc160when the screws are secured. As a result, the locking gear206is free to be raised until the heads234of the screws224contact the shoulders236and to be lowered until the bottom of the locking gear206contacts the top162of the cam disc160. This vertical movement is sufficient for the toothed surface214of the locking gear206to be raised above the toothed surface108of the turret chassis100, thereby enabling the elevation22turret to be unlocked and free to rotate.

FIGS.19A and19Billustrate the turret chassis subassembly230, screw subassembly88, and turret housing36. More particularly, the turret chassis subassembly230is shown assembled and in the process of being mounted on the turret screw subassembly88inFIG.19Aand mounted on the turret screw subassembly inFIG.19B.

When the turret chassis subassembly230is mounted on the turret screw subassembly88, the top40of the turret screw38and the collar66of the turret screw base60pass upwards through the smooth central bore120of the turret chassis100, the smooth central bore178of the cam disc160, and the smooth central bore222of the locking gear206. A retaining ring246is received by the ring slot72in the collar66to prevent the turret chassis subassembly230from being lifted from the turret screw subassembly88. Three recesses245in the bottom116of the turret chassis100receive the heads of the screws80that protrude from the top62of the turret screw base60so the bottom116of the turret chassis100can sit flush against the top92of the turret housing36.

With the turret chassis subassembly230is described above with respect to a turret, which is an elevation turret, one of skill in the art will appreciate that similar designs may be used for turrets that make other adjustments, such as windage turrets. Further, the turret chassis subassembly230described above is described with respect to a zero point adjustment subassembly in accordance with embodiment500. It will be appreciated that the turret chassis subassemblies230described herein can be implemented with any embodiment of the zero point adjustment subassembly500,500′,500″,500′″ or combination of embodiments described herein.

Various modifications and variations of the described compositions and methods of the invention will be apparent to those skilled in the art without departing from the scope and spirit of the invention. One skilled in the art will recognize at once that it would be possible to construct the present invention from a variety of materials and in a variety of different ways. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention should not be unduly limited to such specific embodiments. While the preferred embodiments have been described in detail, and shown in the accompanying drawings, it will be evident that various further modification are possible without departing from the scope of the invention as set forth in the appended claims. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in marksmanship or related fields are intended to be within the scope of the following claims.