GB965217A - Improved gripper mechanisms for interleaving machines - Google Patents

Abstract

965,217. Folding paper. H. GAMBLE. July 18, 1961 [May 12, 1960], No. 16714/60. Heading B6H. A rotary folding machine for particular use in the interleaving of sheets of paper or pleating superposed webs in zig-zag form comprises a pair of co-operating rollers 4, 5 through the nip of which the sheets or webs of material to be interleaved or pleated are passed, each roller having a movable gripper jaw 13 and a fixed jaw 10 set in the surface of the roller and a slot 50, diametrically opposed thereto, which can emit a blast of air, and the two rollers being half a revolution out of phase so that during operation the slot 50 of one roller and the gripper jaw of the other roller will register as they pass through the nip of the two rollers. The slot 50, which extends along the length of each roller communicates via a rotary valve 52 with an air pressure chamber 37 in the roller which chamber is supplied with air under pressure through a duct in the roller shaft 40. A slot 30, similar to the slot 50 but narrower is provided in each roller near the gripper jaw 13 thereof and communicates with the chamber 37 via a rotary valve 32. A row of suction apertures 60 is provided near each slot 50 and communicates via a rotary valve 61 with a vacuum chamber 64. The three rotary valves and the gripper jaw in each roller are cam-controlled. In operation of the machine for interleaving sheets two paper webs are fed respectively between the nips formed by the rollers 4, 5 with a pair of cutting rollers (not shown), which are also half a revolution out of phase with each other. The webs are cut on lines adjacent to the slots 50 in the rollers 4, 5 but not before the leading edge of the web in question is engaged in the nip of the rollers 4, 5. Immediately after the cut has been made the new leading edge of the web is sucked against the surface of the roller 4 or 5 by means of the apertures 60. Owing to the rollers being out of phase the leading and trailing edges of two sheets entrained round one roller are overlapped, as shown, by a sheet entrained round the other roller. As the slot 50 of one roller (4 as shown) passes through the nip between the rollers 4, 5 it emits a blast of air which forces part of the sheet carried by the other roller (5 as shown) into the jaws 10, 13 of that roller which then close. This grip is maintained during a portion of the revolution of the roller 5 so that a transverse fold is made in the sheet. The suction through the apertures 60 is then cut off and the trailing edge of the sheet which was entrained around the roller 4 and passed through the nip and the leading edge of the succeeding sheet entrained around the roller 4 will be biased, by their own resilience, into the fold in the sheet gripped by the jaws 10, 13. After the jaws 10, 13 have passed beyond the nip the jaw 13 is moved to its open position and a blast of air is emitted through the slot 30 in the roller 5 so as to blow the folded sheets away from that roller and to allow the cut and interfolded sheets to build up into a stack. For producing zig-zag folds in continuous webs the cutters are omitted. According to the Provisional Specification then entry of a sheet between the jaws 10,13 may be assisted by suction from within the jaws.