Patent GB-505353-A (GB)
Title: Improvements in and relating to arrangements for spraying the printed sheet coming from a printing press, in order to prevent off-setting of the fresh impression
IPC: B41F23/06
Filed: 1937-08-05
Abstract: 505,353. Spraying - apparatus. SCHNELLPRESSENFABRIK AKT. - GES. HEIDELBERG. Aug. 5, 1937, No. 21594. Convention date, May 5. [Class 69 (iii)] [Also in Groups XVI and III] In an arrangement for spraying with liquid a printed sheet coming from a printing-press in order to prevent off-setting of the fresh impression, the compressed air required for atomizing the liquid to be sprayed is supplied by a pump which is adapted to deliver a constant supply of compressed air to the spraying device for each impression and is connected up directly to the spraying-device so that the whole of the air delivered at each delivery stroke of the pump passes to the spraying- device, means being provided for controlling the quantity of liquid supplied at each printing operation. The spraying-device comprises a casing 13 to which is attached a nozzle 3, and a receptacle 4 for the liquid is connected to the casing by a tube 14. A conical member 16 disposed within the nozzle has an orifice which is closed by a needle 15, the latter extending through a piston 18 and an adjusting-nut 22 beyond the casing. The needle is pressed into closing position by a coil spring 20 arranged between the nut 22 and a fixed collar 19 on the needle, and the piston is depressed by a further coil spring 21. A cylinder 5 is provided with a piston 10 reciprocated by a connecting- rod 9 arranged on a disc or crank actuated from a suitable source of power. Air is sucked in through a valve 28 and then compressed and forced through a tube 6 and bore 25 into the casing 13. The compressed air lifts the piston 18 to open one end of a passage 26 which communicates with air orifices 27 in the nozzle 3. The rising piston 18 engages the collar 19 to lift the needle 15, whereby liquid is released into the established jet of compressed air. The pressure of the air in the casing 13 depends upon the adjustment of the springs by the nut 22. The air stream from the nozzle 3 is cut off at the same time as the liquid control needle 15 cuts off the issue of liquid. The upward movement of the needle is controlled by an eccentric disc 24 provided with scale markings, the disc being set according to the amount of liquid to be released into the air stream. A cook 12 allows the air from the cylinder 5 to be discharged to atmosphere when the spraying device is not to be used. The Specification as open to inspection under Sect. 91 comprises also a control device for preventing the spraying-device from operating in the case where the printing-machine is running with the printing-couple disengaged. This comprises a short exhaust pipe arranged on the cover 11 of the cylinder 5, a valve on the pipe, and an operating-lever for the valve provided with a spring which tends to keep the valve closed. The operating-lever is arranged to be engaged by a push-bar operated from that lever of the printing-machine which disengages the printing-elements of the machine, whereby the piston 10 expels the air from the cylinder 5 through the exhaust pipe when the printing-elements are disengaged. The piston 10 is reciprocated by a means actuated from the printing-machine. The spraying-device is described with the aid of drawings as applied both to a cylinder and a platen printing- machine. This subject-matter does not appear in the Specification as accepted. Reference has been direded by the Comptroller to Specification 478,619, [Group XVI].