Self-evacuating vacuum cleaner

摘要

A vacuum cleaner has an electric motor driving an air impeller for creating suction and a pump impeller which is located in the tank and draws liquid material from the bottom of the tank and expels it from the tank. The vacuum cleaner may have an electrical or mechanical shut-off apparatus which turns off the electric motor if the water level in the tank is too high. The shut-off switch may be bypassed by a user to allow the motor to continue driving the pump impeller to remove liquid from the tank.