ACTUATION DEVICE FOR TWO TYPEWRITER FUNCTIONS

摘要

A cartridge for a typing ribbon and spools for a correcting ribbon are mounted on a common frame which can tilt about a spindle. In a lowered position of the frame the typing line behind a daisy wheel is visible. The frame is raised by a first stroke to the position shown to dispose the typing ribbon over the typing point on the platen. A longer stroke raises the correcting ribbon to the typing point and this longer stroke also actuates an automatic ratchet wheel and pawl type of feed mechanism for the correcting ribbon. The two strokes of the frame are controlled by a disc comprising two cam tracks with a common part and separate parts having different degrees of eccentricity relative to the common part. The grooved cam tracks are so shaped that a follower pin on an arm depending from the frame enters the radially inner track when the disc is rotated clockwise by a reversible electric motor, thereby to raise the frame by the smaller amount, whereas it enters the radially outer track in the case of anticlockwise rotation. The disc also carries a frontal cam which operates a ribbon feed mechanism for the ribbon in a container of the cartridge.