GB583308A - Improvements relating to feeding sheets of flexible material to machines - Google Patents

Abstract

583,308. Feeding sheets. CLARK, D-A. M. (Southworth Machine Co.). July 5, 1945, No. 17170. [Class 100 (i)] In a sheet-feeding machine of the kind in which a pile of sheets 12 is enveloped by a conveyer 16 having open portions 17 and relatively closed portions 18 and in which sheet pickers 52 move through the open portions 17 to raise the trailing edge of the top sheet and hold it above the conveyer until a portion 18 passes between the raised sheet and the stack and finally feeds the separated sheet to a printing or like machine, is so constructed that pickers 52 release the sheet in timed relation to the cycle of travel of the conveyer. The pickers 52 in the form of suction separators are mounted in a carriage 63 which is longitudinally adjustable on guides 66, 67 so as to enable the pickers to operate on sheets of different lengths, and the pickers are raised and lowered by a support adapted to be operated in synchronism with the movements of the conveyer. The conveyer is driven by sprockets on shafts 26, 27, 28, 29 and chains 38, 39, and the raising of the pickers is effected by a pitman 61 attached to a bar 51 in which the pickers are adjustably mounted, the pitman being actuated by a crank on a wheel 62 driven by a gearing from a sprocket in constant engagement with the conveyer chains, so that the timing of the raising and lowering of the pickers depends on the setting of the carriage 63 for sheets of different lengths. The air pressure in the pickers is controlled by a valve 74 operated by a cam 76 driven by gearing from the conveyer shaft 26; and the air pressure is controlled so that the sheets are released to the conveyer with their leading edges in substantially the same position on the conveyer for all lengths of sheets. The pile table 13 is inclined, and is supported by a bracket 85 which is raised automatically by a chain-operated by worm gearing from a ratchet mechanism controlled by a roller 15 engaging the top of the pile. The ratchet 100 -is operated by pawl 102 when the pile needs raising. This pawl is mounted on a pivoted plate 101 which tends to move clockwise in Fig. 1 owing to its centre of gravity being to the right of the shaft 98 of the ratchet wheel. The plate 101 is moved counterclockwise, Fig. 1, by a slotted link 105 actuated by a crank on the shaft of the cam 76, and this movement raises the pile table if the plate is permitted to move clockwise when free for the pawl 102 to engage a further tooth of the ratchet. 100. If the pile does not need raising the clockwise movement of the plate 101 is prevented by a stop on a lever 111 controlled by the rising and falling movement of the roller 15. The front edges of the sheets engage a gauge plate 84, and the separated sheets are controlled by lower guide 22 and upper one 50. The sections 18 of the conveyers are formed of flexible strips secured to bars 41, 42, 43, 44 which are clamped to the conveyer chains.