High speed printing apparatus

摘要

A carriage (22.28) is slidably mounted on a pair of shafts (22.20,22.22) and moves between protracted and retracted positions. A pusher element (22.32) extends downwardly from the the carriage and has a free distal end portion (22.34) attached to a rod (22.36) of a pneumatic cylinder (22.38) which extends in a direction parallel to the longitudinal axes of the shafts. A print head support body (22.44) is pivotably attached to the pusher element adjacent the distal end portion (22.34) and has a pair of followers (22.50) extending laterally from the support body and which are received in track means (22.14) formed in side walls (22.12). The print head support body assumes a first angular orientation at a printing station (22.52) when the carriage is in the protracted position and a second, different angular orientation at an ink replenishing station (22.54) when the carriage is in the retracted position. The track has a path portion (22.14a) which provides a high velocity rectilinear motion for a printing stroke during which a first magnet (22.76) mounted in the pusher element is magnetically coupled to to a second magnet (22.74) mounted in the support body. The print head assembly (22) is laterally positioned by means of a carrier (20) which is magnetically coupled to a magnet assembly (52) slidably received within a tube (16) of non-magnetic material. A timing belt (38) moves the magnet assembly and, concomitantly the carrier, to a selected transverse position between two housings (12,14).