Printing apparatus with cooling of hammer printing coils

摘要

A printing apparatus including a plurality of drive coils for driving printing hammers arranged longitudinally in side-by-side relation at one side of a core of the U-shape. A first cooling fluid passageway is defined inside the core of the U-shape to allow a cooling fluid for cooling the drive coils to flow therethrough, and a second cooling fluid passageway is defined outside the core by a duct to allow the cooling fluid for cooling the drive coils to flow therethrough without escaping to the outside by diffusion. A current of cooling fluid is forcibly fed into these cooling fluid passageways by a fluid machine.