Drive for front stops in sheet deliverers

摘要

The invention relates to a drive for front stops on sheet deliverers for opening and closing the front stops arranged fixedly on the front-stop shaft, initiated by a drive element which is connected to the front-stop shaft via gearing members. The front stops arranged at the leading edge of the sheet pile serve to align the sheets to be delivered which have to be pivoted away to remove sample sheets and carry out similar operations. The object of the invention - to provide a drive for front stops on sheet deliverers, which drive automatically triggers a reversal of movement if a resistance occurs between the front stop and the sheet pile and keeps the pressing force of the front stops low in the critical region and high in the operating position - is achieved in that a cam which acts on the non-return throttle valve and limit switch via the second lever of the angle lever is assigned to the pneumatic cylinder which is generally known as a driving element and can be controlled and acted upon by means of a relay, magnetic valve, non-return throttle valve, pressure and limit switch. <IMAGE>