Patent GB-1386805-A (GB)
Title: Twin-wire paper machine
IPC: D21F9/00
Filed: 1972-04-04
Abstract: 1386805 Paper-making apparatus BLACK CLAWSON CO 4 April 1972 [31 March 1971] 15503/72 Heading D2A Paper forming apparatus comprises wires 12, 13 defiining a forming zone 30 and extending over breast rolls 10, 11 and deflectors 35, the breast roll 11 and deflector 35 associated with the wire 13 being mounted on a frame 60 which is pivoted at 65 and is movable about its pivot between its operative position shown and a retracted position, Fig. 2 (not shown), for servicing of the deflectors and wire changing. The wires are tensioned by rolls 17 and 25 and are driven synchronously through rolls 15, 20 and 21. A headbox 33 supplies stock between the wires to impinge on them below the breast rolls 10, 11. Suction boxes 37, 38, 40 and 41 are provided, the latter boxes retaining the paper sheet on the wire 13 for transfer to a felt 45. Reinforcing baffles 61 within the frame 60 direct liquid removed by the deflectors 35 to an outlet 62. Cables 70 are used to pivot the frame 60 between its two positions. The breast roll 10 and the associated deflectors 35 are mounted on a frame 80 pivoted at 85 for movement by a screw jack 88 between its operative position shown and a retracted wire-changing position, the frame 80 having baffles 81 and a liquid outlet 82. A further frame 90 is pivoted at 85 for movement by a bellows 91 for tensioning the wire 12, and a pressure diaphragm 95 is used to move one end of the roll 17 to keep the wire 12 running straight. The operative position of the frame 80 is fixed by a stop nut in the jack 88 and that of the frame 60 by an adjustable latch mechanism 100. A walkway 115 on the frame 60 is used when it is in its inoperative position. Each deflector 35 is adjustably and replaceably mounted on its frame 60 or 80, Figs. 5 and 6 (not shown). Cable-driven pulleys operate in unison screws disposed at intervals along the deflector support, to alter the angle of the deflector relative to the wire 12 or 13, and the deflector is mounted on its support by pivoted parallel links so that by longitudinal movement of the deflector it is moved towards or away from the wire. The deflector is removably clamped to its support, the clamp being operated by a resilient tube which can be expanded by pressurized air. Wire changing apparatus, Figs. 2 and 3 (not shown), comprises two frames carrying a new wire 13 mounted on removable poles, the apparatus being moved laterally of the machine when the frame 60 has been retracted to a horizontal position with the frames adjacent the rolls 11 and 21. Apparatus for changing the wire 12 comprises an A frame suspended on tracks for movement laterally of the machine and it, carries a new wire 12 on removable poles. The invention includes the conversion of an existing Fourdrinier machine to two wire operation. Other embodiments are described with reference to Figs. 7 and 8 (not shown) in which the wire 13 is supported in a different manner and the felt to which the paper sheet is transferred is differently positioned, and in one embodiment the headbox directs the stock upwardly. The invention extends to apparatus in which the forming zone extends in any direction between horizontal and vertical.