US Patent 7757821 Bicycle hydraulic brake actuation device

A bicycle hydraulic brake actuation device includes a hydraulic master cylinder housing having a bore, a master piston and a radial seal received in the bore a push rod and a lever. The push rod is configured to move the master piston and the radial seal between a neutral position and a braking position. The lever is pivotally attached to the housing for pivotal movement between an at rest position and a brake actuation position. The lever includes a contact surface configured and arranged to move the push rod as the lever is pivoted between the at rest position and the brake actuation position. Further, the push rod includes at least one roller configured to contact to the contact surface of the lever.