Patent ID: 6453507
Filing Date: 2002-09-24
Classification: A47L

Abstract:
A cannister comprising:a chamber divided into upper and lower portions having a reservoir and an air space above the reservoir in said lower portion and a pair of compartments communicating with the lower portion, but not with each other, in the upper portion, a blower providing a source of low and high pressure communicating with said pair of compartments such that one is a negative pressure compartment and the other is a positive pressure compartment, either selectively adapted to be connected to said air space in the lower portion of the chamber to create either a high or a low pressure head therein, valve means in each of said compartments for selecting one or the other to be connected to the air space above the reservoir, a liquid medium in said reservoir having a first depth corresponding to an initial volume of air space above it exposed to the low pressure head when said negative pressure compartment is caused to communicate by the valve means with said lower portion, and a second depth corresponding to a final volume of air space exposed to the high pressure head when said positive pressure compartment is selected by said valve means to communicate with said lower portion, and tubular means having one end opening in said reservoir below the first depth and substantially coextensive with the second depth of the liquid medium, and an opposite end extending above the first depth of the liquid medium from the lower portion and an imperforate portion extending between the two ends, said tubular means opposite end being accessible from the exterior of the cannister for conducting wet or dry material to and wet material from the reservoir solely from said one end.