GB1309804A - Roll doctor apparatus - Google Patents

Abstract

1309804 Doctor apparatus for printing machines JOSEPH WINTERBURN Ltd 28 May 1971 [6 June 1970] 27442/70 Heading B6C [Also in Division D2] A roll doctor apparatus comprises a carrier 16 having an edge portion received in a channelshaped support 17 mounted on the carrier and supporting a doctor 30, and a tube 37 disposed between the carrier edge portion and the support and expansible by the introduction of fluid, e.g. air, into it to pivot the support about the axis of a pivot shaft 32 to cause the doctor to engage the roll 12, the tube 37 being covered by the support 17 and the external surfaces of the support being devoid of ribs. As shown, the roll is a drying roll of a paper-making machine acting on a paper web 13, but the invention may be applied to a bleaching, dyeing or printing machine. A further roll may be disposed beneath the web. The carrier 16 is pivoted on trunnions 19 and is adjustable by means 22 on a link 21. A second link 21 may be provided, the links being on opposite sides of the machine. The support 17 may be continuous and flexible but preferably comprises a plurality of side-byside sections, Fig. 2 (not shown), and each section comprises a sheet-metal Z-section having flanges 24 and 26 and a web 25, and a sheetmetal flange 28 riveted to the flange 26. The doctor 30 is releasably held in a U-shaped part 29 by spring clips 31. Pins 35 on the carrier 16 limit the pivotal movement of the support 17, or the flange 24 may be hooked round the shaft 32 and the pins 35 omitted. A second expansible tube 36 is provided for moving the doctor away from the roll. In a second embodiment, Fig. 3 (not shown), the second expansible tube is disposed at the same side of the carrier 16 as the first expansible tube but at the opposite side of the pivot shaft. The sections of the support 17 may be formed in one piece by extrusion. The second expansible tube may be dispensed with, the doctor being moved away from the roll by gravity.