GB766221A - Improvements in or relating to sheet feeders, particularly for printing machines - Google Patents

Abstract

766,221. Sheet-feeding apparatus. FABER & SCHLEICHER AKT.-GES. March 7, 1955 [March 12, 1954], No. 6580/55. Class 100(1) Pile table and supports. A pile raising device for a sheet feeder in which during the continued feeding of the sheet of a temporarily supported nearly used-up pile a new pile is introduced to be seized and lifted by pile raising rails until united with the remainder of the used-up pile is characterized in that the pile raising rails are pivoted outwardly out of the way of the pile table while being lowered into their new working position after having completed a pile raising operation. The pile raising device include columns 3 on which sockets 4 slide, the latter being operated by endless chain 6. The sockets 4 are provided with dowel pins 12 on which are pivoted the arms of depending U-shaped supporting rails 13 for the pile table 14 on which a stack of sheets 16 is supported. The stack 16 is raised upward until the table 14 encounters supporting pawls 17 when electric switch 18 reverses the drive of the chains 6 to return the rails 13 downwardly at increased speed. In order to clear a new stack 19 placed on the platform 20 the U-shaped rails are swung outwardly by the action of rollers 23 on guide 22 having pivoted portions 25 at their upper ends which give way to allow free passage of the rails upwardly but which engage the rollers 23 when the rails are moved downwardly. Operation of the switch 18 also causes energization of an electromagnet 34 which through links 33, 30 moves a front stop 22 from the position shown in full lines in Fig. 2 to that shown in broken iines so that free passage of the supporting rails is possible. As the rollers 23 run off the bottom end of the guides 22 the rails 13 fall under the table supporting the new stack. At the same time one of the sockets 4 encounters a further switch 27 which reverses the drive to the chain 6 and de-energizes the electromagnet 34 so that the front stop 32 may be returned to its working position by the action of the rails 13 on a lever 137 connected through gear segments 38, 39 and link 31 to the stop 32. The new pile is raised until its upper surface contacts the under surface of the nearly used-up pile when the pressure is relieved on the switch 18 and the normal pile raising mechanism is brought back into action.