GB918008A - Apparatus for separating and conveying sheet-like articles - Google Patents

Abstract

918,008. Feeding sheets. DE STAAT DER NEDERLANDEN, TEN DEZE VERTEGEN WOODIGD DOOR DE DIRECTEUR-GENERAAL DER POSTERIJEN, TELEGRAFIE EN TELEFONIE. June 23, 1961 [June 28, 1960], No.22813/61. Class 100 (1). Apparatus for separating sheets, postal letters, or the like from a pile so that they are uniformly spaced apart on subsequent conveyer means irrespective of the length of the sheets &c., comprises a separator belt which is alternately urged into contact with the top of the pile, and away therefrom by a pressing device under the control of a space-sensing arrangement causes the pressing device to hold the belt away from the pile for a period corresponding to the length of a sheet &c. As shown, a pile 1 of sheets is constantly urged against a slotted upper plate, and the top sheet is separated when a pair of idler rollers 7 moves downwardly to press the lower runs of a pair of separated conveyer belts 2 through slots in the upper plate. A further pair of rollers 7, movable with the first pair, presses the belts 2 against a roller 4 which is normally driven through a slip-clutch in a direction opposing the motion of the sheet and belts 2, substantially as disclosed in Specification 914,292. When a single sheet has been separated, the belts 2 act on the sheet, drive the roller 4 in the opposite direction, and feed the sheet past a light beam from a photo-cell means 6; the sheet is then gripped between the belts 2 and a pair of opposed belts 9 and fed past a second light beam from a photocell means 10. The rollers 7 are raised simultaneously by electromagnetic means in circuit with the photo-cells. In operation, before the first sheet has left the roller 4, its leading edge obstructs the first light beam, and the photo-cell 6 causes the rollers 7 to be raised just as the leading edge of the sheet is gripped by the belts 2, 9. Just before the sheet leaves the first light beam, its leading edge obstructs the second light beam, and the photo-cell 10 causes the rollers 7 to be maintained in the raised position until the trailing edge of the first sheet passes it; whereupon, the rollers 7 fall and separate a second sheet from the pile. Thus each sheet is spaced from another by the distance between the roller 4 and the photo-cell 10, and the distance between the roller 4 and photo-cells 6, 10 can be adjusted to suit the length of sheets to be separated. Where two superposed sheets are separated from the pile 1, the belts 2 act to forward the top one, and the roller 4 returns the bottom one to the pile, since the friction between two sheets is not sufficient to reverse the rotation of roller 4. A small roller 5, on a lever 11 pivoted at 12, is urged by a spring 13 against the roller 4 in the space between the belts 2, and any sheets which leave the pile, during the period in which the rollers 7 are raised, are returned by these rollers to the pile.