Patent ID: 7971689

Claim:
A hydraulic caliper brake assembly for a bicycle comprising: a caliper body; a first chamber installed in the caliper body; a first piston installed in the first chamber; a second piston installed in the first chamber; an inner chamber formed between the first piston and the second piston for receiving brake oil; an outer chamber installed between the second piston and the caliper body for receiving brake oil; an outer valve installed in the second piston for switching flowing of the brake oil between the inner chamber and outer chamber; and an inner valve installed in the second piston for controlling the flow of the brake oil between the inner chamber and the outer chamber, wherein in normal state, the outer valve is closed; when hydraulic pressure in the outer chamber is greater than the hydraulic pressure of the inner chamber, the inner valve will open and the brake oil will return to the inner chamber from the outer chamber; wherein when a small force is applied, the brake oil will flow into the inner chamber; by closing the outer valve; brake oil can not flow into the outer chamber so that the first piston is pushed to have the effect of speed reduction; when the braking force is increased, by opening the outer valve, brake oil will flow to the outer chamber to push the second piston to have the effect of emergent braking.