High-speed wire print head with wire print position shift apparatus

Abstract

A matrix head wire print position shift apparatus which includes a plurality of longitudinally movable print wires which are mounted in an elongated wire housing and are disposed in guides which movably support the longitudinally movable print wires for longitudinal movement within the housing in response to wire drive armatures which cause longitudinal movement of the movable print wires between a non-print position and a print position. A wire drive end bearing plate mounted in the housing supports the front end portions of the longitudinally movable print wires and is transversely shiftable relative to the housing between a first print position and a second print position by a transversely shiftable support device mounted in and guidably supported by the housing. In the first print position the print wire devices are selectably operable to print characters defined by a first set of adjacent substantially tangential circularly shaped dots. In the second print position the wire print devices are selectably operable to repeat printing of the characters with a second set of overlapping circular dots which are offset from the first sets of dots by approximately one half of the diameter of the first set of dots. The shift operating mechanism is mounted in the housing and includes a pivotally mounted rigid non-flexible armature plate member with a non-fixed pivotally movable end portion.