Patent GB-946946-A (GB)
Title: Improvements in sheet separating and forwarding machines
IPC: B65H3/56
Filed: 1961-02-27
Abstract: 946,946. Feeding sheets. H. T. BACKHOUSE. Feb. 26, 1962 [Feb. 27, 1961], No. 7155/61. Heading B6B. Apparatus for separating and forwarding sheets from the top of a pile 20, Fig. 1, comprises two suction grippers 34 operable to grip the rear edge of the uppermost sheet of the pile and to be raised and moved away from one another whilst gripping the sheet, and at least one brush 46, Fig. 9, or equivalent flexible rubbing device located between the grippers 34 to brush or rub the edge portion of each uppermost sheet as it is raised to detach any underneath sheet adhering to the uppermost sheet. The apparatus also includes rising and falling feet 42, Fig. 10 (not shown), engaging the rear top edge of the pile 20, fluffing nozzles 33, a foot 36 which enters below the lifted portion of a sheet and seats on the pile, nozzles 38 which blow air below the lifted sheet to complete its separation, and suction grippers 135 which forward the separated sheet. Further the foot 36 may act as a feeler to control pileraising mechanism. The apparatus is carried by a housing 40, Fig. 1, suspended from tubular frames 21, 22 and includes a drive shaft 24 adjustably connected to a surrounding tube 25 which carries cams 26, 27, 28, Fig. 2, for operting various parts of the apparatus and rotatable parts 30, 31, Fig. 2, of valves controlling the supply of suction and compressed air to the grippers and nozzles. Suction separators. Each gripper 34 is carried by a tubular piston rod 80, Fig. 7, with a recessed head 81 and working in a cylinder 82. A light spring 84 urges the piston upwardly. The lower edge of the cylinder is open to suction applied through a port 85 and tubes 61, 62 on which the gripper is mounted as described later. A small hole 86 is provided in the rod 80. When suction is applied, the rod 80 and gripper are caused to move downwardly until the gripper mouth engages the top sheet and is sealed thereby. Suction then builds up rapidly in the upper end of the cylinder and causes the gripper to rise in the cylinder and to lift the sheet. The two grippers are mounted on sleeves 60 slidable along the horizontal arms 61 of a tubular T-member of which the vertical arm 62 is guided in the housing 40. Rotary movement of the grippers is prevented by rollers 64 thereon engaging forks in a plate 67 carried by the part 62. After the suction-raising of the grippers 34, an additional upward movement is imparted to them against the action of a spring 75 by the cam 26 and a linkage 70, 71, 72, 74. During such movement rollers 68 on the sleeves 60 ride on cam surfaces on a vertically adjustable plate 69, and cause the grippers 34 to move laterally away from one another to tauten the portion of the sheet situated between them. Brushes acting on edge of pile; air blasts acting on edges of sheets.-Two brushes 46, Fig. 9, located between the grippers 34, are provided and are carried by the supporting tube of fishtail fluffing nozzles 33 which are adjustable vertically. Each blowing nozzle 38 comprises an arcuate set of apertures and is adjustable vertically. Presser feet; pile-raising devices.-The foot 36, Fig. 1, is carried by a bar 90 having guide rollers 91, 92 running in slots 93 in fixed members 94. The upward movement of the bar is effected from cam 27 through a linkage 96, 98 and its downward movement by a spring, and the in-and-out movement of the foot is caused by the slots 93 and rollers 91, 92. When the pile needs raising, the foot moves downwardly sufficiently to cause an extension 102 of roller 91 to engage and swing rearwardly a bar 99 so as to cause the bar to operate a switch 103 which initiates raising of the pile. The presser feet 42, Fig. 10 (not shown), seat on the pile at about half way between the grippers 34 and the side edges of the pile. They are operated by suction. Suction forwarding-grippers.-The forwarding nozzles 135 are carried on a cross tube 35, rotatable in a sleeve 120, on the lower ends of arms 121 attached to a shaft 122 and oscillated from the cam 27 against the action of a spring. A roller 140, Fig. 1, on the shaft 122 is held in a slot 141 in a member 142 which is adjustable to vary the inclination of the slot 141 to the vertical. As the roller 140 moves up and down, the grippers 135 are given a lateral movement. To ensure that the grippers remain horizontal a rod 124, Fig. 9, is fixed to an arm 123 on the tube 35 and slides in a guide 125. Suction to the grippers is applied under control of valve 30 through shaft 122 and arms 121, 136. These grippers may, however, be of the same type as the grippers 34. Modifications-One only of the grippers 34 may move outwardly or the two grippers may move different amounts. Furthermore, for wide sheets, two sets of apparatus as described may be employed, in which case both grippers of each set move in the same direction. The mechanically-operated part of the upward movement of the grippers 34 may be dispensed with, the transverse movement being effected after the raising of the grippers by suction.