| 摘要 |
A print hammer assembly for an impact printer includes a hammer (19) having a head portion (47) positioned at one end of a beam (39) which is mounted at a pivot (41) for movement of the hammer between a rest position and a print position. Operation of the hammer (19) is controlled by first and second windings (11, 13) wound around two cores (15, 17) respectively positioned adjacent two flanges (43, 45) of magnetic material provided on the beam (39) on either side of the pivot (41). A drive pulse applied to the first winding (11) pivots the hammer (19) to its print position and a restoring pulse applied to the second winding (13) restores the hammer to its rest position, the restoring action being assisted by a spring (63). In order to avoid interference between the magnetic fields produced by the two windings (11, 13) the two cores (15, 17) are spaced apart and the drive pulse is arranged to terminate before the commencement of the restoring pulse. |
