CANCEL PLATE

PROBLEM TO BE SOLVED: To increase a response of an operation of a clutch piston as well as simplifying a form of a cancel plate 3. SOLUTION: A plurality of stoppers 32 for putting restrictions on diametrical enlargement of a stop ring 4 is formed in an inner circumference of the cancel plate 3. The stopper 32 has a shape made by being punched out in a tongue-piece-like form so as to protrude an opposite side of a cancel oil chamber S2. Accordingly, the stoppers 32 function to put restraints on the diametrical enlargement of the stop ring 4 and function to make a punched out mark 32b made by being punched out in the tongue-piece-like form act as a gateway of a working oil to the cancel oil chamber S2. Besides, if an apical end of the stopper 32 is allowed to face a rotational direction, when a clutch piston 2 returns to a side of a pressurizing chamber S1, a pumping action of the stopper 32 permits the working oil to be rapidly introduced into the cancel oil chamber S2. COPYRIGHT: (C)2008,JPO&INPIT