Auxiliary sight parallelogram mechanics
Soviet MBTs utilize a parallelogram hinge mechanism which is used to link the vertical angular motion of the tank's main gun to the head mirror of the main sight. This is done by having 2 hinged parallelograms, one hinge as a common axis of rotation, which is brought into motion from an axis lever attached to a second hinge mounted through an eccentric bushing on the cannon's trunnions. The hinge for the common axis of rotation transfers vertical motion from the gun to the main sight while also duplicating the motion to the auxiliary sight. Basic parallelogram mechanism viewed from the right side Basic parallelogram mechanism viewed from the top Front view of parallelogram mechanism On the left is the lever arm that connects to the auxiliary sight, and behind the gunner's sight is the connector bridge, which connects the cannon's trunnion through the main parallelogram drive on the right. The main drive has 2 lever arms, which connect to the right side of the sight. T