Abstract:
The ink jet head assembly disclosed herein has modular subassemblies with predetermined relationships between the subassemblies to minimize realignment of the ink stream when a subassembly is replaced in the field. The head assembly is modularized into nozzle, charge electrode, deflection electrode and gutter subassemblies. The charge electrode module is mounted on the nozzle module in a manner such that no field adjustment is necessary to center the charge electrode horizontally to the ink stream. The deflection electrode module is mounted on the gutter module in a manner such that no field adjustment is necessary to center the deflection electrode horizontally to the ink stream. The nozzle and charge electrode subassembly have a preset adjustment, and the gutter and deflection electrode assembly have a preset adjustment such that no field adjustment between these two subassemblies is necessary to maintain a constant flight distance for the ink drops. Finally, the nozzle module is adjustable to reposition the ink stream about the pitch axis (vertical adjustment) and the yaw axis (horizontal adjustment). The yaw axis adjustment may be preset.