Patent GB-354223-A (GB)
Title: Improvements in or relating to sheet feeding devices
IPC: B65H3/38
Filed: 1930-04-02
Abstract: 354,223. Feeding sheets. BUDD MANUFACTURING CO., E. G., 25th Street, Philadelphia, U.S.A.-(Assignees of Eksergian, C. L. ; 12141, Charlevoix Avenue, Detroit, Michigan, U.S.A.) April 2, 1930, No, 10425. Convention date, April 3, 1929. [Classes 100 (i) and 100 (ii).] Sheet-separators, guides, and carriers; tripping- arrangements.-A sheet-feeding device for separating and transferring sheets from a stack to a machine such as a roller-levelling machine is constructed so that the separator can adapt itself to pick up sheets from stacks of varying height. The separator is given a vibrating movement, after it has seized the top sheet, to shake off additional sheets if more than one is picked up, and the separator is automatically returned to the pile if a sheet becomes detached by accident, and in normal conditions is returned as soon as the sheet passes into the machine. The separator comprises a suction head H formed of two rows of rubber suction cups 34 attached by hollow bolts 35 to square tubes 32, Figs. 6 and 7, attached to crossheads 30 pinned to trunnion shafts 29 capable of rotating freely in carrying arms 22 pivoted at 23 to ears 24 on a pedestal secured to the base beams 10 of the rollerlevelling machine R. The arms 22 are fitted with counterweights 25. The cups 34 are adapted to carry the separated sheet and maintain it in a horizontal condition until it is seized by feed rollers 15 driven from the machine R. Guides 20, 21 direct the sheet to hold-down rollers 19 ; or the sheet may be fed directly to the rollers R and the parts 15, 20, 21 dispensed with. The arms 22 are rotated after they have been moved to bring the cups 34 into contact with the pile by means of pneumatic cylinders 55, 70, Fig. 5, The cylinder 55 operates a gear sector 57 freely mounted on a shaft, and this drives a shaft 62 fitted at each end with a crank disc 63 connected by a rod to a disc 54 freely mounted on the shaft 23. To the discs 54 are pivoted rods 52<1>, 53<1>, which are also pivoted to bell-crank levers 52 pinned to the trunnions 29. The head H is thus supported by a parallel link arrangement which normally maintains the sheet horizontal, but permits of its being vibrated when it contacts with the stack. A coiled spring on the shaft 62 returns the shaft to normal position when air is released from the cylinder 55. The air supply to the cylinder 55 and to the cylinder 70, which operates to rotate the shaft 58 and rotates the shaft 23 to give the arms 22 their upward movement, is con. trolled by valves 93, 92, Fig. 5, operated by a piston in a cylinder 90, the air to which is governed by a valve 901 operated by an electromagnet 85. The energization of the magnet 85 is controlled by means of contacts 81 arranged on the head H, and adapted to contact with the sheet prior to the suction cups 34. By this means the vibrator mechanism is operated as soon as the sheet is engaged by the suction cups, and the air is admitted to the cylinder 70 by means of a slide valve 941 operated by a rod 96 from the gear sector 57 which is actuated by the cylinder 55. Similar contacts 86 are engaged by the sheet to maintain the energization of the magnet 85 until the sheet passes into the machine. Should a sheet fall off the cups 34 the de-energization of the magnet 85 causes the arms 22 to return to the stack under the action of a spring, and the detached sheet is guided by guides 87 to return to the pile. The motion of the arms 22 is cushioned at the ends of its stroke by means of spring buffers 79, and by a spring 74, and a dashpot is also used as a cushioning member. The vibrating-mechanism may be put out of action by means of a valve 97, Fig. 5, a check valve 98 permitting the cylinder 55 to operate once in order to open the valve 94<1>. The vacuum produced in the suction cups 34 by their pressure on the sheet is maintained by means of a spring-pressed valve member 39, Figs. 6 and 7, carrying packing 40 which engages a ground valve on the top of each tube 35. The valves are simultaneously opened by link-and-lever mechanism by the engagement of a roller 47, Fig. 1, on the lever mechanism with a stop 49 near the machine R. The shafts 41 are thus rotated and pins 46 on arms 45 fixed to the shaft 41 engage the freely mounted valve members and open them to release the vacuum.