US Patent 7111333 Toilet structure

A toilet includes a bowl having a receiving portion, a converging portion in front of the receiving portion, an injecting portion and an inlet portion at opposite ends of the converging portion, and a discharging pipe behind the receiving portion and communicated with the receiving portion. The bowl has an inlet at an end thereof to communicate outside, two down tunnels on opposite side of the bowl with ends communicated with the inlet and ends extended downwards to a position in front of the receiving portion. Each of down tunnels has a U-turn section that the down tunnels have inward U-turns and are communicated with the converging portion, such that water flowing through the down tunnels will converge together in the converging portion for injecting to the discharging pipe.