Patent ID: 9255634
Filing Date: 2016-02-09
CPC Classification: F16D,F16H

Claim Text:
1. A brake element for a transmission, comprising a first piston configured to press friction plates, and a second piston configured to move the first piston toward a side close to the friction plates, wherein the first piston and the second piston are arranged in series along a stroke direction thereof, in this order from the side of the friction plates, the brake element being characterized in that the first piston is fitted in the second piston in such a manner as to be movable together with the second piston and relatively movable with respect to the second piston, wherein the brake element further comprises: a first oil pressure chamber configured to be supplied with an oil pressure for moving the first piston by a stroke toward the side close to the friction plates; a second oil pressure chamber configured to be supplied with an oil pressure for moving the second piston by a stroke toward the side close to the friction plates; a biasing member acting on the second piston to bias the second piston toward a side away from the friction plates; and a restriction member configured to act on the second piston to prevent a stroke of the second piston toward the side close to the friction plates from becoming greater than a given value, wherein none of the biasing member and the restriction member acts on the first piston.