Epson FX-1180 - Impact Printer, Руководство по обслуживанию

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Operating Principles
2-10 EPSON FX-880/FX-1180 Service Manual
In the figure below, black arrows indicate directional movement when the printhead carriage travels left to
right. In this case, motion transfers through the gear linkage as follows:
Belt Pulley
→
Sun Gear
→
Planet Gear
→
Gear 1
→
Ribbon Driving Gear
Note that the belt pulley and the sun gear are on the same axle and rotate together as a unit.
When the printhead carriage changes direction, the planet gear, which pivots on the planet gear lever,
disengages from gear1, swings over, and engages with gear 2. Motion then continues to pass through
gear 3 and on to the ribbon driving gear. In this way, the ribbon driving gear always turns counter-
clockwise, no matter which direction the printhead is moving.
Planet Gear Lever
Planet Gear
Sun Gear
Belt Pulley
Gear 1
Gear 2
Gear 3
Figure 13. Ribbon Advance Mechanism
The ribbon cartridge itself contains several mechanisms to ensure proper guidance of the ribbon. At the
entrance slot, a pressure roller clamps the ribbon against the advance roller, enabling the advance roller to
“grab” the ribbon and draw it in. The ribbon brake spring, attached to the exit slot of the cartridge case,
prevents slack in the ribbon and keeps its tension at a constant level. Finally, the ribbon mask prevents
the ribbon from brushing against the paper.