PURPOSE: To widen an operating range of a coned disc spring device whose source of elasticity is formed by combining a plurality of coned disc spring elements and to realize various loaded conditions within the operating range by interposing an inversion stopping member between the coned disc spring elements disposed opposite to each other.

CONSTITUTION: A plurality of coned disc spring elements 8 each of which is made to abut on the back of a movable pulley 5 are erected in series with one another outside a V-groove formed between a fixed pulley 4 and the movable pulley 5 both of which are made in pairs and mounted on a pulley shaft 7 with the movable pulley 5 being movable along the pulley shaft 7, and alternate projecting and recessed faces of each coned disc spring element 8 and disposed by a predetermined number while the backs of the elements face each other. A circular inversion-stopping plate 9 crossing the outer peripheral edge of each coned disc spring is enclosed in a space that each pair of adjacent elements forms. If one of the coned disc springs facing each other has reached a point of sticking earlier than the other coned disc spring by reason of its predetermined stress value, further deformation of the former is prevented while deformation of the latter is continued. As the diameter of winding of a V-velt decreases, each coned disc spring element 8 is deformed and approximates a flate plate, but is prevented from being deformed past the point of sticking by the inversion stopping plate 9 and is therefore not inversed.