Abstract: The invention relates to an apparatus for automatic feeding of one document at a time to a document processing machine. The apparatus (10) includes a movable horizontal turntable (12) on which bins (C1, C2, . . . , C8) are affixed, each containing a stack of documents. A drive device (15, 16, 28) controls the displacement of the turntable in order to move a preselected bin into an unloading position (90), facing the processing machine (11). The turntable is provided with bin identification (ME1, ME2, . . . , ME8), and the drive device is controlled by a control circuit (91) that excites the drive device in such a way that the displacement of the turntable to move a preselected bin into the position (90) is effected by the smallest possible rotation. The invention is applicable to sheet feeding to a printing machine.

Abstract: The invention relates to an apparatus for separating and recovering solid particles transported by a gaseous flow. The apparatus includes a separation chamber (40), an admission conduit (43) by which the gaseous flow laden with particles arrives, an escape conduit (44) by which the flow leaves after having been relieved of its particles, a discharge conduit (47) toward which the particles separated from the gaseous flow are urged, a movable flap (49) making it possible with the discharge conduit to comprise a particle recovery box, and a helical device (52) placed in the discharge conduit to prevent the particles thus recovered from being re-aspirated by the rising flow that escapes via the escape conduit (44). The invention is applicable to magnetographic printing machines.

Abstract: The invention relates to a device for the reintroduction of solid developer particles, which have been separated from a gaseous carrier flow, into a reservoir that is open to the air. The derive (60) is disposed between the reservoir (15) and the apparatus (26) for separation and recovery of particles, and it includes a chute (61) into which the discharge conduit (47) of the apparatus discharges. A transport element (65) that slides inside the chute (61) isolates the discharge conduit from ambient atmospheric pressure. This transport element is provided with a cavity (67) in which the particles that drop into the conduit accumulate, and the accumulated particles are then transported outside the chute and drop into the reservoir (15). The invention is applicable to non-impact printing machines.

Abstract: A transistor having an emitter collector path connected in series with a d.c. power supply and a d.c. motor that derives a back emf as a function of motor speed is controlled so current selectively flows from the power supply through the transistor emitter collector path to the motor to drive the motor at differing speeds. The back emf of the motor has a tendency to become excessive for the transistor emitter collector path as the motor speed increases. The voltage of the supply is increased as the back emf increases to prevent the back emf from becoming excessive for the emitter collector path. A control source for the back emf is programmed in accordance with known speed and back emf characteristics of the motor as a function of time. The power supply voltage is increased and decreased in steps in response to variations of the programmed control source being above or below a threshold.