| 摘要 |
<p>The print wire solenoid has a plastics injected unitary bobbin or stator with a core ring or core. A stator forms the bobbin for receiving an electric coil. The stator parts are moulded to a datum surface. A unitary armature has a retraction spring and print wire all anchored to a plastics body, these parts also being positioned w.r.t. a datum surface. The stator and armature assemblies are retained in a metal drawn case. A rebound disc within the case locates the datum surface of the armature in the same plane as that of the stator to define an accurate air gap. The solenoid is for use in a dot matrix printer with e.g. 7 or 9 wires, operating at speeds of up to 1000 impacts per second. The split armature and core provide an increased current rise and reduced response time. The air gap is accurately defined by positioning of the datum surfaces.</p> |
