Master cylinder lever with variable dead band and variable reach adjustment independent of the dead band adjustment
View Patent ↗A master cylinder for a bicycle hydraulic disc brake comprises a housing defining a cylinder, the cylinder having a first and a second end along its axis. A hydraulic fluid reservoir has a port between the hydraulic fluid reservoir and the cylinder, the port having an opening between the first and second cylinder ends. A piston having a seal resides in the cylinder with the seal between the piston and the cylinder. The seal has a leading seal edge with the leading seal edge being movable solely between the first cylinder and the port opening to vary the dead band distance between the leading seal edge and the port opening with the piston in a starting position. A lever is pivotably associated with the housing and operatively associated with the piston for moving the piston within the cylinder between the starting and a pressurized position as the lever is actuated between a rest position and an actuated position. A reach adjustment is operatively associated with the lever for varying the rest position of the lever relative to the master cylinder housing independent of movement of the leading seal edge relative to the port as the reach adjustment varies the rest position of the lever.
1. A master cylinder for a bicycle hydraulic disc brake, the master cylinder comprising:
a housing defining a cylinder, the cylinder having a first and a second end along its axis;
a hydraulic fluid reservoir with a port between the hydraulic fluid reservoir and the cylinder, the port having an opening between the first and second cylinder ends;
a piston having a seal between the cylinder and the piston, the seal having a leading seal edge:
a dead band adjustment operatively associated with the piston for moving the leading seal edge solely between the first cylinder end and the port opening without passing the port opening to vary a dead band distance between the leading seal edge and the port opening with the piston in a starting position;
a lever pivotably associated with the housing and operatively associated with the piston for moving the piston within the cylinder between a starting and a pressurized position as the lever is actuated between a rest position and an actuated position; and
a reach adjustment operatively associated with the lever for varying the rest position of the lever relative to the master cylinder housing independent of movement of the leading seal edge relative to the port as the reach adjustment varies the rest position of the lever.