| 摘要 |
<p>The cassette system for single-printing element typewriters and similar office machines avoids smudging as well as leaves a free view for the operator in the printing zone. The unit comprises horseshoe-shaped cassettes (3-5) wrapping the printing head (2) and the selected tape is placed in the working position (10) by magnetic control. The injection moulded housings are provided with guide ribs and slots for threading in as well as for feed out of the tape, and their correct alignment with reference to the platen (28) and the head (2) is ensured by bottoms (25). The latter have projections for positive location of the housings (3-5) through engagement of grooves in the latter. Lowering of a cassette into the rest position (11) is through magnet attraction. The bottoms (25) also include drive and pinch rollers for transport of the tape, the rotation of the rollers ensured by magnetic coupling. The smallest cassette (3) is for a tape that is least used, while cassette (5) is for the most frequently used ribbon.</p> |
