Abstract: A system for constraining a moving device to parallel plane translational movement, the system including a base; a frame fixed to the base and including frame portions disposed at the periphery of a region; a movable device disposed in the region; and a plurality of coupling elements connected between the frame portions and the movable device so as to provide support thereof, each of the coupling elements being capable of bending motion and incapable of twisting motion so as to guide movement of the movable device along a path including a series of planes all oriented substantially parallel to each other. The coupling elements restrict movement of the device to a desired sequential parallel plane path.

Abstract: A pivoting, compensating parallelogram linkage system converts rotary motion into axial linear motion of a portion thereof suited for critical uses such as carriage of a moving mirror in a Michelson interferometer. The compensating includes a coupling provision that in response to angle change in one part of the linkage imposes an equal but opposite angle change in another part of the linkage. The coupling may include a motor to reciprocate the portion usable as a carriage.