Self-centering guide rod system for a rifle scope turret
An optic device turret for adjusting the optical element of the optic device. A spiral cam mechanism is engaged with the turret to define a maximum and minimum adjustment of the optical element. A rotation indicator displays the amount a knob has been rotated.
1. A rifle scope comprising:
a scope body;
a moveable optical element defining an optical axis connected to the scope body;
a turret having a screw defining a screw axis and operably connected to the optical element for changing the optical axis in response to rotation of the screw;
a spiral cam mechanism comprising a stop element and connected to the screw and having a bushing configured to permit passage of the screw;
the stop element defining a guide surface wrapping about the screw axis and terminating at first and second ends;
a cylindrical body operable to engage the guide surface, and to engage the first and second ends, the engagement of the first and second ends defining rotational limits of the turret; wherein each of the first and second ends are at different radial distances from the screw axis.
2. The rifle scope of claim 1 wherein the guide surface is defined by a channel.
3. The rifle scope of claim 2 wherein the stop element has a planar surface perpendicular to the screw axis, and the channel is defined in the planar surface.
4. The rifle scope of claim 1 wherein the guide surface includes a plurality of concentric arcs each centered on the screw axis and substantially encompassing the screw axis, the guide surface including a transition segment connecting an end of a first one of the plurality of concentric arcs to an end of a second one of the plurality of concentric arcs, such that a stepped spiral is formed.
5. A rifle scope with spiral cam mechanism comprising:
a scope body;
a moveable optical element defining an optical axis connected to the scope body;
a turret having a screw operably connected to the moveable optical element for adjusting the optical axis in response to rotation of the screw;
a spiral cam mechanism having a bushing configured to permit passage of the screw, the spiral cam mechanism defining a first stop surface positioned for engagement by a cylindrical body to limit rotation of the turret, such that the position at which the cylindrical body engages the first stop surface defines a zero position of the screw and the moveable optical element;
the spiral cam mechanism defining a second stop surface positioned for engagement by a cylindrical body to limit rotation of the turret, such that the position at which the cylindrical body engages the second stop surface defines a maximum point of displacement of the screw and the moveable optical element; wherein the first stop surface and second stop surface are connected by a channel and further wherein the channel comprises a stepped spiral.
6. The rifle scope of claim 5 , wherein the first stop surface and second stop surface are recessed portions of the spiral cam mechanism.
7. The rifle scope of claim 5 wherein the cylindrical body is a cam pin.
8. The rifle scope of claim 5 , wherein the turret is a windage turret.
9. The rifle scope of claim 8 , further comprising a second windage turret.