Abstract: A method for rewinding a web of sheet material for making a log wound on a core in a winding zone formed between an upper winding roller and a lower winding roller. Upstream of the winding zone a cradle is provided for feeding the core connected to the support of the lower roller and located beneath the upper winding roller. At least a portion of the cradle is movable with respect to the support of the lower roller and is capable of lowering or rising towards/away from the upper winding roller. For each step of feeding a core, the movable portion can be displaced from a first position of load of the core to a second position wherein the core contacts the upper roller. When the upper roller contacts the core for reaching the winding zone it moves first on the movable portion and then on a fixed portion of the cradle that is integral to the support wherein the axle rotates of the lower roller.

Abstract: A method for rewinding a web of sheet material for making a log wound on a core in a winding zone formed between an upper winding roller and a lower winding roller. Upstream of the winding zone a cradle is provided for feeding the core connected to the support of the lower roller and located beneath the upper winding roller. At least a portion of the cradle is movable with respect to the support of the lower roller and is capable of lowering or rising towards/away from the upper winding roller. For each step of feeding a core, the movable portion can be displaced from a first position of load of the core to a second position wherein the core contacts the upper roller. When the upper roller contacts the core for reaching the winding zone it moves first on the movable portion and then on a fixed portion of the cradle that is integral to the support wherein the axle rotates of the lower roller.

Abstract: A rewinding method for a web (1) of sheet material for making a log (2a) wound on a core (20a,20b,20c) in a winding zone (4) formed between an upper winding roller (5) and a lower winding roller (6), in particular for the production of rolls of toilet paper, rolls of all purpose tissue paper or non woven fabric for household use, industrial rolls and the like. Upstream of the winding zone (4) a cradle (21,26) is provided for feeding the core (20b) connected to the support (29) of the lower roller and located beneath the upper winding roller (5). At least a portion (21) of the cradle (21,26) is movable with respect to the support (29) of the lower roller (5) and is capable of lowering or rising towards/away from the upper winding roller (5). For each step of feeding a core (20b), the movable portion (21) can be displaced from a first position of load of the core (20b) to a second position wherein the core (20b) contacts the upper roller (5).

Abstract: A method and a machine for rewinding a web (1) for making a log (2a), in particular for the production of rolls of toilet paper, rolls of all purpose wipers or household non woven fabric, industrial rolls and the like. The rewinding is carried out according to the steps of feeding a web (1) of paper into a winding cradle (4); arranging upstream of the cradle (4) a counter support roller (8) comprising at least a cutting slit (9) transversal to the web and a cutting roller (11) with a blade (10) so that it is possible the cut or tear the web (1) for contact of the blade (10) with the web (1); concluding the winding of the log (2a); winding the new log (2b) up to a predetermined length of the web (1); rotating with sliding the counter support roller (8) on the web (1) during the winding of the new log (2b) for causing the blade (10) to cut the web in a desired chosen location.

Abstract: A machine (1) for interfolding sheet material (4a, 4b) starting from a web (3a, 3b) of paper and the like. A sequence of offset sheets (4a, 4b) is formed on folding rollers (7a, 7b) which are counter-rotating with respect to each other and have a plurality of circumferential grooves (15a, 15b), in which oscillating folding arms engage (20a, 20b) so as to form a stack (17) of interfolded sheets (4a, 4b). The folding arms (20a, 20b) have pivots (21) very close to the periphery of the folding rollers (7a, 7b), inside or outside of the grooves (15a, 15b). Moreover they can be operated by a crank mechanism that allows to the grooves (15a, 15b) to be shallow enough also in case of rollers (7a, 7b) of enlarged diameter. For the same reason, the folding arms (20a, 20b) can have a bent portion.

Abstract: A method and a machine for the production of interfolded stacks (17) formed by a plurality of sheets (4a,4b) comprising the steps of: transversally cutting or tearing sheets obtained from at least one web (3a,3b) and offset with respect to one another so that a sequence of offset sheets is created; passage of the sheets on folding rollers (7a,7b) which comprise sucking means for the alternate holding of the sheets (4a,4b) in order to obtain an interfolded disposition; formation of a continuous interfolded stack downstream of the folding rollers. Upstream of the folding a step of treatment of the sheets is provided in order to make them, at least in certain zones (14), enough permeable to air, in particular through perforating means. These perforating means can be provided on rollers (10a,10b) having sharpened points (11a,11b).