PURPOSE: To engage a lift ring with the center of a disc surely, by raising a supporting member by a plate material, which is moved vertically while holding the horizontal state in accordance with the operation of a vertically shaking lift lever, and a lifting member consisting of a pin or the like provided in a prescribed position of the lift lever.

CONSTITUTION: A pair of lift levers 31 bent into the shape of L are provided in a side plate part, which is formed by bending upward a prescribed position of a substrate, so that they can be shaked vertically in their bending parts around a shaft 34. Lift ring lifting pins 35 are fixed pivotally to tip parts of lower sides of lift levers 31, and lift ring pulling-up projecting parts 36 are provided in prescribed positions higher than pins 35. An oblong hole is provided in one lift lever 31 instead of the pin 35, and a pin 39 provided in a prescribed position of a lift ring lifting slider 37 which is fitted vertically slidably to a guide pin 38, which is provided in a prescribed position of the substrate, while holding the horizontal state is inserted through the oblong hole.