Zero-stop turret

A telescopic sight comprising:

• an elongate external housing of generally cylindrical shape providing a sealed enclosure for optical components held within the housing between opposite objective and eyepiece ends of the housing, said optical components comprising an adjustable sighting assembly;
• a turret mounted externally on a central portion of the housing, the turret comprising a turret assembly and affixed externally to the turret assembly a turret knob,
• wherein:
• the turret assembly comprises:
• a base portion, the base portion having a seat for fixing the turret assembly to an aperture in a housing of a telescopic sight;
• a plunger extending along an axis of the turret within the base portion of the turret assembly, and being movable along said axis to actuate a movable member of the adjustable sighting assembly within said housing;
• an adjustment mechanism linked to the plunger, the adjustment mechanism being rotateably mounted to the base portion and being configured, in use, to drive axial movement of the plunger along said axis;
• and
• the turret knob is removeably affixed externally to the turret assembly whereby the turret knob when affixed to the turret assembly is attached to the adjustment mechanism whereby, in use, a user can turn the turret knob to effect rotation of the adjustment mechanism in opposite first and second rotational directions, to move the plunger axially in opposite first and second axial directions by manually turning the turret knob in corresponding rotational directions;
• wherein the turret assembly further comprises a zero-stop mechanism for limiting the rotation of the adjustment mechanism in both rotational directions, wherein the zero-stop mechanism comprises:
• a first stop member for limiting rotation of the adjustment mechanism, the first stop member being fixed to the base portion;
• a second stop member for limiting rotation of the adjustment mechanism, the second stop member being releasably secured to the adjustment mechanism whereby the second stop member when secured to the adjustment mechanism is rotationally carried by rotational movement of the adjustment mechanism and when released from the adjustment mechanism is freed from being carried by said rotational movement;
• a movement limit member extending around the turret assembly, the movement limit member comprising:
• (i) a substantially annular main body, said main body being rotatable about said axis with respect to both the base portion and the adjustment mechanism;
• and (ii) a lug extending away from said main body and being guided by said rotation of said main body along a circular path, and the lug having a first side and opposite the first side, a second side,
• and wherein, the configuration of the lug, the first stop member and the second stop member when rotationally secured to the adjustment mechanism is such that:
• in the first rotational direction the second stop member comes into contact with the first side of the lug whereby said main body is rotated in the first rotational direction by the lug as the lug is moved along the circular path by the second stop member until the second side of the lug comes into contact with the first stop member, thereby limiting the rotation of the adjustment mechanism in the first rotational direction;
• and
• in the second rotational direction, the second stop member comes into contact with the second side of the lug whereby said main body is rotated in the second rotational direction by the lug as the lug is moved along the circular path until the first side of the lug comes into contact with the first stop member, thereby limiting the rotation of the adjustment mechanism in the second rotational direction;
• and wherein, the configuration of the lug, the first stop member and the second stop member when rotationally released from the adjustment mechanism is such that the adjustment mechanism is freed from said rotational limits of the zero-stop mechanism.

A method of setting a zero-stop of a sighting adjustment turret to limit an adjustment range of a sighting element of a telescopic sight, said turret comprising a turret assembly and a turret knob removeably affixed externally to the turret assembly, the turret assembly comprising:

• a base portion fixed to said telescopic sight;
• an adjustment mechanism that is rotatable in opposite first and second rotational directions around a turret axis and which is linked to a plunger that is movable in opposite first and second axial directions in response to rotation of the adjustment mechanism in, respectively, said first and second rotational directions;
• and
• a zero-stop mechanism for limiting the rotation of the adjustment mechanism in both directions of rotation, the zero-stop mechanism comprising a first stop member fixed to said fixed base portion, a second stop member removeably affixed to the adjustment member, and a movement limit member extending around the adjustment mechanism and comprising a substantially annular main body and a lug extending away from said main body, the lug comprising first and second sides (91, 92) facing, respectively, in opposite rotational directions;
• wherein the method comprises:
• removing the turret knob from the turret assembly;
• releasing the second stop member from the adjustment mechanism so that the second stop member is freed from being carried by rotational movement of the adjustment mechanism;
• making a desired sighting adjustment of a telescopic scope;
• adjusting the rotational position of the second stop member with respect to the adjustment mechanism in either the first direction of rotation or the second direction of rotation until the first side of the lug comes into contact with one of the first and second stop members and the second side of the lug comes into contact with the other one of the first and second stop members;
• securing the second stop member to the adjustment mechanism so that the second stop member will rotate in unison with the adjustment mechanism about the axis of the turret and thereby setting in one of said rotational direction a first rotation limit corresponding to the desired sighting adjustment, a second rotation limit in the other rotational direction being set by contact between the lug and both the first and second stop members after more than one full turn of the adjustment mechanism and less than two full turns of the adjustment mechanism;
• and
• affixing the turret knob to the turret assembly.