Abstract: The disclosed continuous ink jet printer nozzle assembly defines a flow path having a powered sonic oscillator associated therewith for inputing vibrations to ink flowing in the path, and a cavity for holding closely adjacent but isolated from the ink flow path one or more sensors operable to detect ink vibrations and/or temperatures immediately downstream from the oscillator, whereby such sensed information can be used in feedback controls for changing input power to the oscillator and/or heater/cooler unit upstream of the oscillator, for stabilizing the printed ink pattern. The nozzle assembly further is formed of three subassemblies: an ink driver subassembly having the powered oscillator and sensor(s), and filter and orifice subassemblies respectively adapted to be connected in serial self-aligned sealed orientations to the exterior upstream and downstream sides of the ink driver subassembly, thereby allowing field replacement of the filter and/or orifice subassemblies.

Abstract: A ribbon tensioning device for use in a single pass typewriter and/or printer ribbon cartridge having a supply spool and a takeup spool between which the ribbon is transferred incrementally by a capstan drive assembly, includes first and second arms joined at first ends and mounted for pivotal movement thereat in the cartridge adjacent the ribbon spools. The arms are biased in opposing relation with the free ends of the arms engaging the peripheries of respective spools, each arm exerting a pressure against a corresponding spool to maintain the tension on the ribbon extending therebetween substantially constant throughout the transfer thereof between spools. A high friction material is applied to the arm of the device which engages the supply spool and a low friction roller is mounted on the arm of the device which engages the takeup spool.