Abstract: A replaceable filter cartridge is mounted in a housing body having an inlet and an outlet permanently attached to a line carrying the liquid to be filtered. The filter cartridge contains activated charcoal. An outlet in the filter cartridge can be closed by a buoyant poppet valve which is normally held out of engagement with its valve seat by a trigger wire. An impeller is rotated by the flow of the liquid through the cartridge and the impeller drives a toothed disc which abrades the trigger wire. The abrading eventually cuts through the wire and releases the poppet which then seats against the valve seat of the outlet and renders the cartridge inoperative. The amount of abrading of the trigger wire is proportional to the flow of liquid through the cartridge and the trigger wire is sized to fail after a quantity of liquid has passed through the filter sufficient to exhaust the filtering capabilities of the cartridge. The spent cartridge must be replaced with a new filter cartridge.

Abstract: A valve in which a rotary valve member includes rollers which support two endless belts to roll along the cylindrical wall of a valve housing as the valve member is opened and closed. The belts seal tightly against the wall and close off inlet and outlet ports when the valve member is in its closed position.

Abstract: A hand operated ink stamp comprising an outer casing having an open bottom and an opening in the upper surface. A printing die impregnated with ink is disposed within the casing and is carried by a die holder having an upper magnetically susceptible surface. Mounted within the upper portion of the casing is a magnet, and the magnetic force will hold the die holder and die at a raised position above the surface to be printed. A stem is mounted for sliding movement in the opening in the upper surface of the casing and is connected through a ball and socket joint to the die holder. Manually depressing the stem will overcome the magnetic force to release the die holder from the magnet and cause the die to contact the surface to be printed. The position of the magnet within the casing can be adjusted to thereby vary the printing impression.