GB966957A - Improvements in and relating to the handling of fibrous cement sheets - Google Patents

Abstract

966,957. Feeding sheets. F. L. SMIDTH & CO. A.S. Feb. 18, 1963, No. 6482/63. Heading B6B. [Also in Division B8] In apparatus for separating sheets by suction from the top of a stack consisting of partially hardened fibrous cement sheets alternating with separator sheets, the suction lifting device has a downwardly open suction chamber of substantially the same dimensions as the sheets and has curved supports therein, so that when a sheet is grasped it is curved to produce shearing forces between the sheet and the sheet immediately below to facilitate the separation. As shown in Fig. 1, a carriage 2 is reciprocable along a runway 1 and carries two vertically movable suction devices 3, 4 having open-ended suction chambers 5, 6, respectively. Initially, there is a single central stack 7 of alternating steel and fibrous cement sheets on a support 10, and the chamber 6 is lowered to grasp a steel sheet and then rise with the sheet. The carriage 2 is moved to the right, the chamber 6 is lowered to deposit the steel sheet on a support 10 to form a stack 9, and the chamber 5 is lowered to grasp a cement sheet on the central stack. Both chambers rise, the carriage is moved to the left, and both chambers are then lowered. The cement sheet is deposited on a support 10 to form a stack 8, the chamber 6 grasps a steel sheet on the central stack, and a fresh working cycle commences. The suction chambers are about the same size as the sheets, the supports inside the chambers comprising spaced transverse ribs within the open faces against which the sheets are sucked and curved. The steel sheets are curved convexly by the chambers 6, and the cement sheets are curved concavely but to a lesser degree, to ensure separation from the stack 7. In a modification, the support ribs 17, 18, Fig. 10, are arranged longitudinally, and certain ones, such as 18, are arranged to move upwardly when engaged by a sheet, and thus cause the sheet to be curved. Where the cement sheets, such as 12, Fig. 10, to be separated are corrugated, the edges 15 of the chamber are also corrugated at their outer edges; and in the case of fixed transverse support ribs, the edge faces of the ribs are corrugated. Fig. 12 shows a single lifting device having two suction chambers 20 which can separate sheets from the tops of two abutting stacks and then deposit these sheets on two stacks which are separated by a suitable distance. The chambers 20 are suspended in a guide 21 for horizontal movement by compressed air cylinders 23. Suction is applied to one chamber through a pipe 25, and the two chambers are connected by a flexible pipe 24 which allows the chambers to be moved apart so that the two sheets can be deposited on two separated stacks. The stack supports 10, Fig. 1, may be fixed pallets, but may be movable conveyer belts or trucks.