Device for controlling advance and return movements of original table of

Abstract

A device for controlling advance and return movements of an original table of an electrostatic copying apparatus wherein the table is advanced in timed relationship with the movement of a photosensitive element and returned under the action of a spring to its initial position comprising a first shaft rotatable in timed relationship with the movement of said photosensitive element, a second shaft rotated at a predetermined speed in one direction, a stepped pulley mounted on said first shaft for free rotation relative thereto, a first pulley co-axially mounted on said first shaft through an one-way clutch operable when said first pulley rotates relative to said second shaft in said direction of rotation thereof, a first wire passing around said first pulley and which is connected at its one end to a smaller diameter portion of said stepped pulley and at the other end through a spring to said original table, a second wire passing around a larger diameter portion of said stepped pulley and connected at its opposite ends to said original table for movement therewith, ratchet means provided on said stepped pulley for pivotal movement under resilience, latch means operable to engage with said ratchet means at the initial position thereby initiating the advance movement of said original table while tensioning said spring, releasing means for releasing said latch means to disengage said stepped pulley from said first shaft at a predetermined angular position thereof thereby causing the return movement of said original table under the action of said spring to the original position, and operating means for selectively operating said ratchet means at the initial position to cause engagement between the latter and said latch means.