A hydraulic braking system for a bicycle may include a hydraulic control device that is configured with multiple timing ports positioned within a stroke of a piston of the hydraulic control device. The multiple timing ports are located at different positions along an operational and/or axial length of a cylinder of the hydraulic control device.

A master cylinder device includes a reservoir tank, a master cylinder, a piston, and a pair of cup seals. The master cylinder includes a cylinder body having a cylinder chamber and a master port. The piston is inserted into the cylinder chamber, and has a relief port that communicates with the master port. The cup seals are provided on an inner circumference of the cylinder chamber, being positioned in front and rear of the master port, and seals a space between the inner circumference of the cylinder chamber and an outer circumference of the piston. The relief port is closed by the front cup seal, as the piston moves forward, to generate brake fluid pressure in a brake fluid in a hydraulic chamber. The relief port is tilted from a front side to a rear side, from the outer circumference toward an inner circumference of the piston.

A hydraulic brake assembly (12) includes a housing (24) having first and second side-by-side bores (30), each defining a respective master cylinder assembly. Each master cylinder assembly includes a master cylinder piston (32) slidably movable by actuation of a respective brake pedal (18a, 18b) to and between an active position and an inactive position. A spool (74) slidably disposed within a piston bore (70) of the master cylinder piston (32) is operable in a first mode to direct hydraulic fluid from a quick-fill chamber (62) to a master cylinder chamber (50) at a first pressure upon initial movement of the master cylinder piston (32) from the inactive position toward the active position. The spool (74) is operable in a second mode to direct hydraulic fluid from the quick-fill chamber (62) to a tank (20) when pressure in the master cylinder chamber (50) reaches a predefined threshold.

A hydraulic brake assembly (12) includes a housing (24) having first and second side-by-side bores (30), each defining a respective master cylinder assembly. Each master cylinder assembly includes a master cylinder piston (32) slidably movable by actuation of a respective brake pedal (18a, 18b) to and between an active position and an inactive position. A spool (74) slidably disposed within a piston bore (70) of the master cylinder piston (32) is operable in a first mode to direct hydraulic fluid from a quick-fill chamber (62) to a master cylinder chamber (50) at a first pressure upon initial movement of the master cylinder piston (32) from the inactive position toward the active position. The spool (74) is operable in a second mode to direct hydraulic fluid from the quick-fill chamber (62) to a tank (20) when pressure in the master cylinder chamber (50) reaches a predefined threshold.

A pump includes a fluid outflow mechanism that causes the brake fluid in the discharge chamber to flow out into the suction chamber in accordance with decrease in the volume of the discharge chamber when the feed ring of the valve portion decreases the volume of the discharge chamber in cooperation with the increasing movement of the volume of the first pump chamber in a state where the first pump chamber and the discharge chamber are filled with brake fluid in the suction step.

A vehicle braking device includes a first pressurizing unit including a cylinder, a piston slidable in the cylinder, an electric motor that drives the piston, and an output chamber partitioned by the cylinder and the piston. The first pressurizing unit is configured such that a connection state between the output chamber and a reservoir is switched between communication and cut-off states according to the piston position, and the first pressurizing unit is capable of pressurizing fluid by decreasing a volume of the output chamber by movement of the piston to one axial direction side; a pressure sensor that detects a pressure of the output chamber; and an estimation unit that executes a position estimation process of moving the piston and estimating a switching position of the piston at which the connection state of the output chamber and the reservoir is switched based on a detection value of the pressure sensor.

Disclosed herein is a master cylinder. The master cylinder according to the present embodiment includes a hydraulic block provided with a main bore formed therein in an axial direction, a first piston having one side inserted into the main bore to be displaceable and the other side exposed to an outside of the hydraulic block and connected to a brake pedal, a mounting block provided with a sub bore formed therein in the axial direction and the sub bore where the first piston is inserted thereinto to be displaceable and passes therethrough and a connection port connecting the sub bore and a reservoir, a cap provided on one side of the first piston, and a gap flow path formed by a gap between the first piston and the cap so that a first liquid pressure chamber partitioned by the first piston communicates with the connection port on the main bore.

A master cylinder is described. The master cylinder includes a chamber delimited by a piston and supplied from a brake fluid reservoir installed on the top of the master cylinder by an end fitting engaged in a nozzle on the body of the master cylinder. The piston has a nose of reduced section upstream of its skirt guided in the bore hole of the master cylinder and the nozzle is connected to the chamber by a drill hole issuing into the chamber at least partly upstream of the piston in rest position. A valve module is installed in the drill hole to manage communication between the reservoir and the chamber as a function of the position of the piston and the pressure in the chamber with respect to the pressure in the reservoir.

A master cylinder is described. The master cylinder includes a chamber delimited by a piston and supplied from a brake fluid reservoir installed on the top of the master cylinder by an end fitting engaged in a nozzle on the body of the master cylinder. The piston has a nose of reduced section upstream of its skirt guided in the bore hole of the master cylinder and the nozzle is connected to the chamber by a drill hole issuing into the chamber at least partly upstream of the piston in rest position. A valve module is installed in the drill hole to manage communication between the reservoir and the chamber as a function of the position of the piston and the pressure in the chamber with respect to the pressure in the reservoir.

A brake assembly includes a reservoir body adapted to store a brake fluid and defining a cylinder bore, and a piston adapted to reciprocate inside the cylinder bore. The brake assembly also includes a base bracket pivotably coupled to a reservoir body and adapted to be mounted to a handlebar, and a handle pivotally coupled to the base bracket and adapted to pivot relative to the base bracket. A drive link is pivotable coupled to the reservoir body and is configured to pivot relative to the reservoir body to advance the piston inside the cylinder bore in response to the pressing of the handle. The handle is configured to be set at a plurality of angular positions with respect to the reservoir body by pivoting the base bracket relative to the reservoir body.