Low tension sheet winding method, and the airtight structure of the piston used in the practice of the method

摘要

PROBLEM TO BE SOLVED: To enable winding of a sheet with winding tension as set from the beginning of the sheet winding while reducing mechanical loss at a portion of each piston of first and second pistons constituting a winding shaft.;SOLUTION: Before winding of a sheet in which a winding core M is set in a winding shaft K, by applying negative pressure to each of first and second pistons P₁, P₂, the plurality of first and second pistons P₁, P₂ are separated from an inner peripheral surface of a cylinder block B and a side surface of a slide ring S respectively and brought into a non-contact state. Then, by applying pressure, which increases in proportion to a winding diameter of the sheet with respect to the winding core M, only to the plurality of first pistons P₁, winding torque is generated in the winding core M, and thus the sheet is wound with low tension.;COPYRIGHT: (C)2016,JPO&INPIT