Abstract: A compact printhead assembly is designed for employment in a soldering operation without the need for fluxes and without conducting the operation in a confined chamber. A self-contained printhead assembly has an internal reservoir and internal heating elements for raising the temperature above the melting temperature of solder or other liquid to be dispensed in microdroplets from a working surface at one end of the printhead housing. A jetting device containing an electro-mechanical transducer is pulsed to produced droplets at an exit orifice located at the working surface. Inert gas is preheated by the housing and delivered to the working surface to establish an oxygen-free atmosphere around the exit orifice and between the working surface and a substrate located a working distance away, whereby microdrops can be formed and deposited without harmful oxidation.

Abstract: An apparatus for printing paper sheets includes a sheet transport supported by a frame for carrying sheets past a print head along a generally planar paper path. The print head is mounted in a fixed but adjustable relationship with respect to the transport by a shaft rotatably mounted at each end to the frame to extend generally perpendicular to the paper path. A mounting plate has the print head secured thereto, and is in turn attached to the shaft whereby the mounting plate and the print head thereon are pivotable with the shaft from a normal position near the paper path to provide access to the path. A stop is provided for limiting pivotal movement of the plate towards the paper path. Provision is made for adjustment of the skew angle of the print head with respect to paper path, the lateral placement of the print head with respect to the path, and the distance of the print head from the paper path when in the normal position.

Abstract: An ink jet fluid system and process of startup and shutdown is provided which includes a print head having a fluid manifold and at least one orifice for forming a jet drop printing stream. Inlet and outlet valves are connected to inlet and outlet openings of the print head. During shutdown, fluid is continuously circulated around the print head through a bypass line while the outlet of the print head is connected to a source of reduced pressure to prevent fluid from flowing through the orifice. At startup, the inlet and outlet valves are actuated to provide a continuous flow of fluid under pressure to the print head. In another embodiment of the invention, a fluid system is provided for a multiple print head device and provides for independent control of the fluid pressure in each print head.