| 摘要 |
<p>Power drive and timing train mechanism for serial printer mounted in an injection molded base by means of novel plastic bearings and without the usual fastening hardware, and including jack shaft belt-driven by start-stop on demand motor and, through two electrically operated clutches, separately driving power transfer and take up reel shafts, latter lifts ribbon to active position and rotates take up reel connected to print head by novel flexible driven member and retaining coupling at each end for simplified assembly and providing superior impact and vibration dampening properties in linearly moving print head laterally and return thereof by spring. After first or take up reel clutch is deenergized to effect spring return of print head to normal position, if print head velocity exceeds predetermined value interpreted by optical switch thereon and stationary sensing rack comprising pulse generator, take up reel clutch is caused to be pulsed to reduce velocity. During return of print head to home position, paper and ribbon drives are actuated by power transfer shaft through the second clutch with that clutch being deenergized by a second optical switch.</p> |
