| 摘要 |
796,687. Sheet feeding and delivery apparatus. CARMICHAEL & CO., Ltd., P. Nov. 30, 1955 [Dec. 1, 1954], No. 34831/54. Classes 100(1) and 100(2). Sheet transfer apparatus for use in printing, folding, envelope-making &c. apparatus comprises a series of suction cylinders each connected to a suction main, a trigger valve in each suction connection except that to the first cylinder, and each valve is adapted to be opened in response to a decrease in pressure inside one of the preceding cylinders when a sheet is held on that cylinder. As shown, sheets B separated from a pile W are transferred by suction cylinders 1-5 through a machine, the interior of each cylinder being connected to a main pipe 7 communicating with a vacuum pump. The cylinder 1 is connected to the pipe 7 by a pipe 8, a regulator valve 9, and a fixed manifold 6; the cylinder 2 is connected to the pipe 7 by a pipe 10, a trigger valve 12, and fixed manifold 11: and the other cylinders are connected to the pipe 7 through an arrangement similar to that for the cylinder 2. The trigger valve 12 has a piston valve 12a which is urged by gravity or a light spring to closed position, and the casing is connected to the interior of the cylinder 1: by this arrangement, unless there is a sheet B on the cylinder 1 closing the orifices o therein and causing a decrease in pressure in the interior of the cylinder 1, the valve 12 will not be opened, and the cylinder 2 will not be connected to the vacuum source. Similarly, unless a sheet passes over the cylinder 2, the next cylinder 3 will not be connected to the vacuum source, and so on. The regulator valve 9 is set so that when there is no sheet on the cylinder 1 there is only a low pressure in that cylinder, and the valve 12 will therefore close or remain closed, as the case may be. The trigger valves 12, 16, &c. can each be associated with cut-outs to stop the apparatus if a sheet fails to pass any of the transfer points: or a trigger valve can control the application of suction to a printing-cylinder which is rotated by suctionoperated means: or the first trigger valve can be operated by an electric solenoid which is energized by a detector switch responsive to a sheet entering the transfer apparatus, and so replace the regulator valve 9. |
