GB1260004A - Method and apparatus for winding up travelling webs - Google Patents

Abstract

1,260,004. Winding webs. A. AHLSTROM OSAKEYHTIO. 15 May, 1969 [15 May, 1968; 26 June, 1968], No. 24849/69. Heading B8R. In a web winding machine the pressures acting on the roll being wound are controlled so as to ensure the formation of a uniform roll. As shown, a roll 14 is supported on two winding rollers 10, 12, one of which is driven, whilst a rider roller 18 is urged against the top of the roll 14 by an arrangement including an hydraulic cylinder 28; the rollers 10 and 12 are each arranged so that deflection of the roller axis under stress is compensated for, whereby straight line contact between roller and roll is always maintained despite increase in weight of the roll during winding and despite the fact that the position of the contact line moves, relative to the centre of the winding nip between the rollers 10, 12, as the diameter of the wound roll increases. Thus, roller 10 comprises a rotatable shell 30, a hollow interior and a supporting beam 34 which takes up the bending stresses; roller 12 is similar, and the beams 34, 36 of the two rollers are linked by a pantograph mechanism to the core 15 of the roll so that the beams are turned, as the roll diameter increases, to compensate for the changing pressures on the rolls, whereby straight line contact between the roll and each roller is maintained; at the same time the pantograph mechanism operates a valve 78 which controls the supply of oil to the cylinder 28 so that the pressure applied by the roller 18 decreases as the weight of the roll increases, whereby the load on the rollers 10, 12 is maintained constant to ensure uniform winding tightness from layer to layer. Another valve, similar to valve 78 also controls the pressure in expansion chambers 54, 56 provided in the rollers 10, 12 and adjustment of this pressure enables the winding tightness to be varied from layer to layer in a predetermined manner. Modified arrangements for the mechanical linkage between beams 34 and 36 and for the support mechanism associated with the roller 18 are described with reference to Figs. 3 to 9 (not shown). The machine may also include a roller associated with a pressure cell for detecting variations in tension of the web supplied to the roll, the pressure in chamber 56 being automatically adjusted in dependence upon these variations.