Abstract: A water closet has a flush tank which reduces the head of flush water presented to a downwardly converging bowl which receives waste to be discharged through an outlet to a siphon trap, the bowl having a rim which causes the flush water to be presented to the trap in a vortex fashion. The trap is U-shaped and includes an upleg and downleg, the upleg having a converging-diverging cross-section to cause the dischrge to be pushed quickly from the bowl into the downleg, which becomes filled and creates a siphon. As waste travels down the downleg it passes through an expansion chamber which imparts a swirling movement to the waste and is again restricted at the outlet, which prevents air from entering the trapway and breaking the siphon.

Abstract: A one-piece toilet bowl and rim capable of generating superior vortex water flushing action is disclosed. Metering of the volume, flow rate, and directional orientation of the flushing water into, and within the internal rim cavity is developed by two flow passages of different diameters. The angular orientation of the flow passages generates fluid flow within the rim cavity in opposite directions. The flushing water flowing within the rim cavity is angularly discharged through a continuously slotted discharge orifice circumferentially located along the underside of the rim. The angularly discharged flushing water generates superior vortex flushing action within the toilet bowl.