GB591433A - Improvements in sheet separating mechanism - Google Patents

Abstract

591,433. Feeding sheets. HOE & CO., Ltd., R., and BATTEY, A. P. May 10, 1945, No. 11688. [Class 100 (i)] A device for separating sheets from a pile preparatory to feeding to printing or other machines comprises a suction device 1 mounted on a pivoted member 2 which can move around a pivot 4 and so bend a portion of the top sheet of a pile when pressure is lowered in a chamber 3 forming part of a foot attached to a tube 7 connected to a piston 8 capable of moving in a fixed double-ended cylinder 9. When air pressure is reduced in a vacuum line 11, pressure is reduced on the lower side of the piston 8 via an aperture 10, and the pressure on the upper side of the piston is maintained at atmosphere owing to the suction device 1 not being closed, although the upper part of the cylinder 9 is connected to the line 11 via an aperture 14. The tube 7 extends through the piston 8 to connect the upper part of cylinder 9 to the suction device 1. When the foot and suction device 1 engage the pile the reduction of pressure in the chamber 3, which occurs when the engagement of the device 1 with the pile cuts off the connection of tube 7 to the atmosphere, causes first the pivotal motion of the member 2 and consequent bending of the sheet as shown in Fig. 3, and also causes diminution of pressure on the upper part of the piston 8 through escape of air past an aperture 15 in the tube 7 above the piston. The tube 7 thus is raised owing to the differential pressure action on the piston 8. A valve member 19 may be used to control the aperture 15, the valve being attached by a rod 18 to the suction device, so that the action of the pivoted member 2 takes place quickly. To cause the raising action of the piston 8 to be slow at first an adjustable " bleed " aperture 16 controlled by a valve 17 is formed in the cylinder 9, and when the piston passes this aperture its motion is accelerated. The sucker assembly can be adjusted angularly so as to allow its line of action to be set diagonally, and the cylinder 9 can be given a motion parallel to the top of the pile to forward the separated sheet, and a locking device may prevent the forwarding action until the piston 8 has completed its upward movement.