Adjustable control mechanism for optical instruments

Abstract

A control mechanism slidably positions an optical component, such as a focusing lens or a zoom lens, along an optical axis of an optical instrument, such as a telescope or spotting scope. The controller includes a rocker manually rotatable about an axis substantially parallel to the optical axis of the instrument, and an actuating pin rotatably secured to the rocker and extending vertically into the interior of the instrument for actuating a lever arm that reciprocates the optical component. Vertical reciprocating travel of the actuating pin in response to clockwise or counterclockwise rotation of the rocker pivots one end of the lever arm through an angle about a fixed pivot. This rotates a cam on an opposite end of the lever arm through an angle that controls sliding reciprocating travel of the optical component. A drive pin on the optical component is driven by arcuate travel of the cam to slidably position the optical component along the optical axis of the instrument in response to clockwise or counterclockwise rotation of the rocker. In another embodiment, the rocker has pivotally mounted side flaps attached to the rocker by hinge pins. The ends of the side flaps have fixed pins which engage guide slots on the body of the instrument housing. This combination guides angular travel of the side flaps in response to rotation of the rocker.