Valmet Paper Machinery Inc.

Wilhelm Landin

Juha Honkala

Ari Lassila

Timo Hirvonen

Seppo Pukkinen

Pekka Koivukunnas

Juhani Niskanen

Ville Korhonen

Timo Pirinen

Risto Turunen

A calender in a paper or board machine comprises a calender frame, at least two soft-faced rolls mounted on the calender frame and at least one hard roll mounted on the calender frame in a manner that allows the hard roll to be displaced between a first position in which it forms calendering nips with the two soft-faced rolls and a second position in which it is spaced from the soft-faced rolls. During threading of the web; while the calender is in operation, the hard roll is shifted to its second position, the web is passed over the soft-faced rolls, and the hard roll is shifted back to its first position and brings the web into the nips between the hard roll and the soft-faced rolls.

Calender with pivotally displaceable roll

The invention concerns a calender, in particular a supercalender, on whose frame (1) a set of rolls (2) is mounted, which comprises an upper roll (3), a lower roll (4), and several intermediate rolls (5) placed between the upper roll and the lower roll. The rolls (3, 4, 5) are supported on the frame (1) by the intermediate structure of the base parts (34, 47, 54) being vertically displaceable along guides (7) provided in the frame. Of the base parts, at least the base parts (54) of the intermediate rolls can be positioned in the vertical direction by means of lifting spindles (6) provided in the frame (1) and by means of spindle nuts (56) provided on the spindle. The base parts (54) of the intermediate rolls are supported on the lifting spindles (6) being vertically displaceable by means of pressure-medium operated relief devices (57) arranged between the base parts (54) and the spindle nuts (56) to reduce the journal loads on the rolls (5). The bearing housings (51) of the intermediate rolls are attached to the base parts (54) being pivotable relative to an articulation shaft (53) parallel to the axes of the rolls (3, 4, 5) and supported on the base parts (54) by means of attenuation devices (10) to equalize the forces resulting from movements of the nips (N.sub.1, N.sub.2, N.sub.3, N.sub.4) between the rolls and to attenuate oscillations of the rolls (5).

Calender, in particular a supercalender with multiple relief devices

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Helsinki, Finland

Juha Honkala