It is described a winding apparatus for wrapping a material around a core of flat shape that rotates around a rotation axis rotating in its turn with a circular trajectory, controlling the laws of motion both of the core rotation around its axis and of the circular trajectory of its rotation axis, motor driven independently by means of electric cams, such as to cancel the variations of position and speed of the material at the entrance of the core The winding apparatus is used for producing electric energy accumulating devices.

A winder includes a winding mechanism, a chamber housing the winding mechanism, at least one vacuum pump, and a product case. The winding mechanism is configured to wind a belt-shaped raw film around a winding core. The belt-shaped raw film is composed of a plurality of electrodes and a plurality of separating films. The at least one vacuum pump is configured to suck air into the chamber. The product case is configured to house a plurality of winding products each formed by winding the raw film with use of the winding mechanism disposed in the chamber.

A device for winding an electrode plate includes a feed roller configured to guide a first electrode plate or a second electrode plate, each of the first electrode plate and the second electrode plate including a plurality of electrode tabs protruding from one side, a deformation reducing member spaced apart from an outer circumferential surface of one end of the feed roller and configured to guide the electrode tabs fed to the feed roller to be brought into close contact with the outer circumferential surface of the one end of the feed roller to reduce deformation of the electrode tabs, and a winding unit configured to wind together the first electrode plate or the second electrode plate transferred by the feed roller and a separator interposed between the first electrode plate and the second electrode plate.