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.
A shuttling printer mechanism suitable for use with dot forming print elements is disclosed. A mechanical linear reciprocable drive apparatus acting as close as possible through the center of percussion of the print head and suspension assembly reciprocates the print head back and forth along a desired print line adjacent to a platen. The drive apparatus utilizes a unique non-circular gear arrangement. The suspension and frame design is adapted to provide print line visibility so that printed characters may be seen as they are formed. The reciprocation drive operates without orthogonal forces. It provides a purely linear drive force so that the machine is free of unwanted vibrations in other planes or axes.
A cartridge ribbon lift apparatus is provided in which a pivotally mounted cartridge, containing a ribbon, is pivoted upward to a printing position by a linkage which is operated by a solenoid. When the cartridge reaches the printing position a second linkage latches the cartridge in the printing position for repeat and burst speed printing and the cartridge remains in the printing position as long as the solenoid remains energized. While the cartridge is latched in the printing position the first linkage is restored to its initial operating position.
