Teletype Corporation

John E Randolph

Alfred Z Purzycki

In a cartridge for an endless typewriter ribbon, a fresh ribbon is stored in the cartridge with a substantial length of ribbon wound in a convolute around a roller. When the cartridge is mounted in a printing apparatus, the ribbon is drawn from the cartridge, exhausting the convolute. When the cartridge is fully mounted in position in the printer, a single path of ribbon extends into the cartridge and through an opening along a chord of the roller and out from the cartridge. A brake is provided to limit motion of the roller so as to preclude premature unwinding of the convolute and to limit oscillation of the roller during operation of the printer. With the normal operating path of the ribbon extending through the chord-oriented slot of the roller, ribbon can readily be rewound onto the roller upon removal of the cartridge from the printer.

Ribbon cartridge having a convolute-forming roller

In order to advance an inked ribbon in a printing apparatus in which a printing carriage mechanism moves across the width of a platen, one-way brakes are placed on ribbon guide rollers on the printing carriage mechanism to permit relative movement between the printing carriage mechanism and the inked ribbon as the printing carriage mechanism is advancing from left-to-right across the paper. One-way brakes are placed on return rollers in the ribbon path in order to prevent the inked ribbon from moving with respect to the platen as the printing carriage mechanism is moving from left-to-right across the paper. When the printing carriage mechanism moves from right-to-left in order to return to the left-hand margin, the one-way brakes on the ribbon guide rollers on the printing carriage mechanism apply substantial friction to the inked ribbon and drag the inked ribbon with the printing carriage mechanism as the printing carriage mechanism returns from right-to-left. In this same motion the return rollers rotate freely to alow the inked ribbon to move in accordance with the printing carriage mechanism motion.

Ribbon advancing mechanism

A carriage for positioning a print mechanism in front of a record medium and moving the print mechanism back and forth in front of the record medium with facility for retracting the print mechanism to permit insertion of a ribbon and biasing the print mechanism forward toward the record medium against an adjustable stop. The retracting mechanism being further adjustable for retracting the printing mechanism completely out of the carriage for removal therefrom.

Printer carriage

A drive mechanism includes a nut on a rotatable lead screw. The nut has a partially threaded and partially unthreaded axial bore and a mounting assembly to couple it to a linearly movable carriage. The mounting assembly includes diametrically opposed carriage-engaging lugs positioned on the drive nut near the threaded bore end and a locking arm slidably keyed into a slot in the carriage which mounts the drive nut for universal radial floating on the carriage. The drive nut may become slightly skewed relative to the axis of the lead screw in order to minimize frictional forces due to tolerance variations, bow in the lead screw, or axial misalignment of the lead screw with carriage guide rods. Kinetic-energy-induced bounce forces of the carriage are damped by a coil spring which also maintains the lugs against the carriage.

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Palatine, IL, United States of America

John E Randolph