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 application_number US 77446091 A description the calendering unit shown in fig1 which comprises two calenders 10 30 fitted one after the other is intended for two sided calendering of the web w i e for calendering in which each side of the web w contacts a hard roll if it is not necessary that the web w be calendered in the sameway at both sides it is possible to use just one calender 10 or 30 in the calendering unit thus in fig1 the first calender in the calendering unit is denoted generally with the reference numeral 10 the calender 10 comprises a calender frame 11 mounted on a base b on which frame two soft faced rolls13 and 14 are mounted for rotation by means of bearing brackets 15 and 16 between the soft faced rolls 13 14 a hard roll 12 is supported by bearingbrackets 17 the hard roll 12 which may be a driving roll forms calendering nips n 1 and n 2 with the soft faced calender rolls 13and 14 the calender 10 is a three roll so called horizontal calender.