Patent ID: 8104598

Claim:
A friction device for an automatic transmission, comprising: an elastomeric member disposed in a transmission case; a circumferential retainer disposed on an inner circumference of the transmission case and configured to retain the elastomeric member in the transmission case; a center support disposed in the transmission case adjacent the elastomeric member; a piston disposed in a pressure chamber formed in the center support and provided with a return force by contact with the elastomeric member; and a plurality of plates operationally-connected with the inner circumference of the transmission case and in contact with the piston; wherein the retainer includes a protruding portion configured to substantially align the center axis of the elastomeric member with the center axis of the transmission case; wherein an inner diameter of the elastomeric member is about equal to or greater than an inner diameter of the retainer; and wherein the protruding portion extends from an outer circumference of a seating portion of the retainer in a thickness direction of the retainer.