Serial printing apparatus

摘要

Resilient tongues project from a central hub and carry two or more type members. The hub is rotated to a position in which the tongue carrying the desired type member is in a printing position facing a paper supporting platen. The hub is then shifted along the axis of the selected tongue so that the required type member is in a printing position. A drive motor for rotating the hub is connected to the hub by a universal joint to compensate for the shifting of the hub. The universal joint comprises a biased presser member to eliminate lost motion in the rotational direction. A stopper member is provided so that the bending characteristics of the selected tongue are the same no matter which type member is selected. A hammer drives the type member against the paper to print. The resilient tongues are formed of a thermoplastic resin mixed with glass or carbon fibers and the type members may be formed separately from the tongues, fixed thereto and plated with metal. The hub may be formed in two or more sections, with each section carrying some of the resilient tongues. The tongues are bent in such a manner that all of the type members lie in a common plane. The angles between the type members and the tongues are selected in such a manner that all of the type members strike the paper perpendicular to the platen.