Abstract: The method and device are used to move a center core 2 from a given delivery passage to a given position and position the same at the given position, the center core 2 including in the outer periphery thereof a flange portion 12 for bonding a magnetic disk sheet thereto, a circular recess portion 15 disposed on one side of the center core 2 and inside the flange portion 12 with a stepped portion 11 between them, and a center hole 13 formed in the central portion of center core 2.

Abstract: A method for delivering a predetermined amount of a fluid comprises the steps of pressurizing the fluid, passing it through a pressure feed passageway, opening and closing the pressure feed passageway, and thereby delivering a predetermined amount of the fluid out of the pressure feed passageway. A rotatable shaft is located in the pressure feed passageway. The rotatable shaft is provided with a passageway part, which constitutes part of the pressure feed passageway. The fluid is delivered by rotating the rotatable shaft to a predetermined orientation, in which the passageway part communicates with the pressure feed passageway outside of the passageway part. After a predetermined amount of the fluid has been delivered, the rotatable shaft rotates by a predetermined angle to an orientation, in which the passageway part does not communicate with the pressure feed passageway outside of the passageway part, and the delivery of the fluid is thereby stopped.