Abstract: A developing apparatus for use with a photoreceptor to form a toner image, including a housing to store toner therein; an agitator having a shaft whose length is smaller than the inside dimension of the housing; a gear mechanism to transmit a driving force to the shaft member; and a coupling to couple the gear and the shaft, wherein the coupling is positioned inside the housing.

Abstract: In a copying apparatus equipped with a sorter having a bin unit slidably mounted on the main frame and driven up and down by a vertically supported feed screw, heavy loading of the bin with multiple copies throws the same off balance resulting in strain on the feed screw unit and producing unwanted vibrations. By connecting the bin to the feed screw through an elastically supported nut and positively slidably guiding the movement of the nut in a vertical guide parallel to the feed screw, unwanted vibrations and strains on the feed screw connection are avoided.