Control for rearview mirror

Claim 1

Remote control actuating mechanism for adjusting the angular position of an outside vehicle rearview mirror, comprising a master control device and a slave device, said control device having a hydraulic control cylinder and a manually operable control piston reciprocable therein, said slave device having a hydraulic slave cylinder and a slave piston reciprocable therein, a first hydraulic circuit including a conduit filled with hydraulic fluid communicating at its ends with said cylinders at one side of the pistons therein, a second hydraulic circuit including a conduit filled with hydraulic fluid communicating at its ends with said cylinders at the opposite side of the pistons therein, said control piston having an external knob for manually moving said control piston in one direction or the other and thereby effecting a corresponding movement of said slave piston by hydraulic fluid pressure in one of said circuits, a cylinder providing a reservoir for hydraulic fluid, passages placing said reservoir in communication with both of said first and second hydraulic circuits, a plunger reciprocable in said reservoir to control the pressure of the hydraulic fluid therein and in said first and seconD hydraulic circuits, means for fixing said plunger in axially adjusted position within said reservoir, passage means leading to said reservoir through a port in the face of said plunger to admit air to said reservoir when said plunger is withdrawn for the purpose of replenishing said reservoir, thereby facilitating withdrawal of said plunger, and a check valve in said passage means preventing flow of fluid out of said reservoir.