Print mechanism for wire printer

Abstract

A print mechanism for a wire printer has a robust single-turn closed-loop transformer secondary winding as the moving part for driving a print wire into and out of a print position. Each secondary winding threads a transformer core on which is wound a multi-turn primary winding. A stack of such secondary windings, arranged with print wires in a closely spaced print row across the stack is supported in a static magnetic field produced by a magnetic assembly. Energization of a selected primary winding induces a large current flow in its associated secondary winding which reacts with the static magnetic field to drive the associated print wire into the print position. In one embodiment, the stack of secondary windings are all mounted on a single pivot and each secondary winding swings about the pivot as a whole upon energization of its associated primary winding. In another embodiment each secondary winding of the stack is formed so as to be elastically deformable whereby the portion of the secondary winding carrying the print wire is deflected into the print position under energization of its associated primary winding.