Abstract: A marking apparatus is disclosed in which a propellant stream is passed through a channel and directed toward a substrate. A liquid marking material, such as ink, is controllably introduced into the propellant stream and imparted with sufficient kinetic energy thereby to be made incident upon a substrate. A multiplicity of channels for directing the propellant and marking material allow for high throughput, high resolution marking. Multiple marking materials may be introduced into the channel and mixed therein prior to being made incident on the substrate, or mixed or superimposed on the substrate without registration. One example is a single-pass, full-color printer.

Abstract: Apparatus for supplying liquid from a tank (12) to an inlet of a pump (40) without interruption when the condition of the tank changes to a reversed gravity condition, includes a hollow, standpipe body (20) having a first inlet opening (26) and a second inlet opening (28). Internal walls divide the standpipe into a first compartment (32) in communication with the tank through first opening (26), a second compartment (36) which is in communication with a pump inlet port (38) connected to the inlet of pump (40), and a third compartment (42) which is in communication with the tank through second inlet opening (28). Third compartment (42) is also in communication with the discharge of pump (40) through a bleed line (46). The first and second, and second and third compartments are in fluid connection through holes (48) and (50) respectively, in the dividing walls. A vertically moveable spool (52) includes a weighted upper disc (56) and a weighted lower disc (54).