GB953946A - Improvements relating to printing presses - Google Patents

Abstract

953,946. Feedings heets. LINOTYPE & MACHINERY Ltd. Feb. 28, 1963 [Feb. 28, 1962], No. 7795/62. Heading B6B. [Also in Divisions G1 and G4] In apparatus for registering a sheet on a feed board in a printing press, there is optical or sonic means for producing a beam projected through the path of the sheet on to a transducer, which beam is at least partially obstructed as the sheet moves into register, a comparator fed with the transducer output and with a reference voltage which is pre-set and representative of a correctly registered sheet, and means to halt sheet movement when there is coincidence between the transducer output and the reference voltage. Front and/or side register may be effected by a pulling or pushing means. In one construction, the main body 1 of a side lay is secured to the feed board (2, not shown), a lay 3 is slidable within slots in the body 1 by means of a rod 4 which is reciprocated in synchronism with the press, and a piston-rod 46 is secured to the lay 3 and a piston 6 in a cylinder 7 in the body 1. When the lay 3 moves to the right, the partial vacuum created in the cylinder 7 communicates with a sheet 39 to be registered through a bore 9 and several small bores 11 in the body 1, and through a bore 10, passage 12, bore 13, and apertures 16, 17, the latter being in the lay 3. Since the apertures 16, 17 have a larger area than the bores 13, the sheet 39 is moved by the lay 3 to the right, and the suction at 11 smooths the sheet. When the lay 3 has moved the sheet 39 into register position, a valve (20, not shown) in a cross-bore 19 is released by a solenoid, is urged by a coil spring to close the bore 10 to cut off suction at 16, 17, and the lay 3 moves on, leaving the sheet 39 in registered position and held there by the suction at 11. An ultrasonic transmitter (Fig. 4, not shown) produces a beam which is directed through a pipe 29, a slot 25 in the lay 3, a bore 26 in the body 1, and a pipe 27 to an ultrasonic transducer. The output of the latter is amplified, and fed through an integrator to a comparator which compares the voltage received with that received from a pre-set reference voltage source. When the two voltages are equal, the comparator emits a signal to a switching unit, deenergizing the solenoid of the valve in the crossbore 19. When a sheet 39 is being moved to the right by the lay 3, the side edge of the sheet moves into the path of the ultrasonic beam, and the sheet is in register when a predetermined portion of the energy of the beam is cut off by the sheet. If the sheet is moved too far to the right, i.e. mis-registered, the comparator will give visual and/or audible indication, and trip the sheet feed of the press. In modifications, the piston 6 is omitted, and vacuum is applied cyclically from an external source; a vented rotary solenoid operates in the cross-bore 19; and the ultrasonic system is replaced by a light beam and photo-electric cell system. The sheet can be registered also at the front edge by using a number of the above devices. Instead of pulling the sheet into registered position, the sheet can be pushed by raised stops.