Patent GB-464873-A (GB)
Title: Improvements in or relating to sheet-feeding machines
IPC: B65H9/10
Filed: 1935-12-06
Abstract: 464,873. Feeding sheets. BACKHOUSE, H. T. Dec. 6,1935, Nos. 33894 /35 and 15120/36. [Class 100 (i)] In a sheet-feeding mechanism the sheets are moved laterally on the feed board for side registering purposes by pneumatic means, the sheets being gripped directly by suckers or by grippers operated by pneumatic means and adjustably mounted on a bar extending across the feed board. In Fig. 1 a suction tube 4 is carried by a piston 3 which is movable in a cylinder 1 against the action of a spring 5, and a suction conduit 7 enables the air pressure to be reduced in the tube and cylinder 1, ports 9, 10 being provided in a sleeve 8 embracing the conduit 7 for this purpose. When the sheet is engaged by an adjustable nozzle on the tube 4, formed of an annular rubber ring 20 arranged in a countersunk recess, the piston 3 is moved across the feed board 2 to bring the edge of the sheet into contact with a side-lay 16, the rate of movement of the piston being controlled by a valve 12 controlling the port 10. The front of the conduit 7 is inclined at an angle of 30‹ and as the sleeve 8 moves over the conduit 7 it covers the port 9 thus cutting off connection between the conduit 7 and the tube 4, thereby preventing the action of further suction to the sheet. This is timed to correspond with the engagement of the edge of the sheet with the side-lay 16. The piston continues its movement until the sucker 4 is drawn off the edge of the sheet, when the suction is cut off, and the parts return to their initial position under the action of the spring 5. During the side-registering, pivoted sheetsmoothing devices 17 are moved into contact with the sheet by a projection carried by the piston, and after the registering operation the smoother 17 is released and raised by spring action. The suction conduit may be formed on the piston and lead through valve mechanism to the sucker, the attachment to it being made by a flexible rubber connection. In a further modification, Fig. 7, the cylinder 41 carrying the sucker moves over a fixed piston 40, and a second bore 42 connected to the sucker moves over the fixed suction conduit 44. The port 45 leading to the sucker is cut off from the conduit 44 while the cylinder 41 is still connected thereto via a port 43, or a controlled needle valve. The sucker is finally connected to atmosphere via ports 45, 46, 47. The conduit 44 may be dispensed with and the main suction conduit connected to the interior of a fixed piston 40. The sucker mouth may consist of four vertical apertures which are cut off in succession from the suction conduit so as to cut off the suction gradually from the sheet. In a further modification, Fig. 10, a relief valve 60 is adapted to connect the cylinder to atmosphere when the sucker is cut off from the tube 7, and a fixed choke 65 connects the suction conduit to the cylinder, the choke being formed with a conical head 66 and a passage 67 of predetermined size to provide the desired rate of application of suction to the cylinder. The valve 60 is fitted with a spring which puts the air port 62 in communication with the cylinder via a groove 61, a port 63, and a passage 64. In Fig. 11, the sucker 4 is carried by a bellows 69 sliding on guides 70 and separate suction conduits 71, 72, are provided for the bellows and sucker. A trigger 74 is operable by the sheet as it reaches the side stop to cause a rack 72 to operate a vent valve 79, and the rack may also operate a valve 82 to cut off connection between the sucker and the conduit 72. In a further modification the sucker is operated by lever mechanism from a spring-controlled flexible diaphragm attached to a suction chamber. The sucker may be mounted at a height from the sheet which is adjustable, and the spring controlling the moving cylinder or piston may also be adjustable.