Winding core for attaching to winding shaft for winding of endless flexible material web to winder, has adjusting unit for adjusting diameter of core surface to be wound between diameter-reduced idle and expanded operating conditions

摘要

The core (10) has an adjusting unit adjusting diameter of a core surface to be wound between diameter-reduced idle condition and expanded operating condition, where a surface of a winding is jointless-formed in the expanded operating condition. The adjusting unit comprises a secondary sleeve (20) flexibly rotatable to an extent and made of glass fiber, where an outer surface of the sleeve forms the core surface. Supporting elements are formed inside the sleeve, and run lengthwise over the core surface. The elements are separated at pre-determined distance in the expanded operating condition.