GB928198A - Apparatus for raising stacks of flat articles in article separating machines - Google Patents

Abstract

928,198. Feeding sheets. SIEMENS & HALSKE A.G. May 2, 1961 [May 2, 1960], No. 15931/61. Class 100 (1). In apparatus for separating flat articles, such as letters, of varying thickness, from the top of a stack wherein the top of the stack is maintained at a constant level, photo-electric means including a first and a second light beam is provided for controlling the feed of the stack table upwardly, the first light beam scanning the top of the stack to control the step-wise upward movement of the stack, and the second light beam scanning the body of the stack and causing a continuous upward movement of the stack support when all the articles have been removed therefrom. As shown, an endless chain conveyer 4 is provided with a number of tables 5 supporting stacks 14 of letters, the top chain pulley 6 being connected to a motor 8 through worm wheels 13, a solenoid-operated clutch 12, shaft 11, and belt and pulley drive 9, 10. One light beam, from a lamp 29 (not shown) arranged to the left of the operative stack 14, is directed upwardly and is reflected by an inclined mirror across the top of the stack at the predetermined working level of a suction separator 15; this light beam, when unimpeded, can fall on a photo-cell in the circuit of a solenoid which controls the clutch 12. A second light beam from the lamp is directed downwardly, and is reflected by an inclined mirror upwardly along an inclined path which passes through the table 5 and stack 14; if there are no letters left on the table 5, this light beam can impinge on a photocell (31, not shown) in a control circuit which controls the clutch 12 and causes a continuous drive to the conveyer 4 until the empty table 5 has been carried upwardly and around the top pulley 6 and a new stack of letters has arrived in the region of the separator 15. The control circuit is conditioned by three cams. One cam is on the shaft of the separator 15 and ensures that the stack is only raised when the separator has left the top of the stack. The other two cams are on the chain wheel shaft 11, one of these being arranged to switch over the control of the clutch 12 from the first light beam to the second just before the last letters of the stack have been separated, whereupon the third cam controls the clutch 12 in conjunction with the second light beam. Sheet separators.-The suction separator 15 is coupled by lazy tongs 17 operated by means of cams 18, 19 and a fixed cam curve 20, and pivoted levers 21, 22 are arranged to guide the tongs. The separator 15 lifts a letter from the stack and places it between rollers 23, 24 which feed it to conveyer belts 25. The roller 23 is carried by a pivoted arm which is rocked towards and away from the roller 24.