Abstract: A platen assembly, including a cylindrical platen, for advancing a web of record material through a printing device, the record material having perforations along its borders for receiving pins disposed in pin sprocket wheel assemblies mounted on opposite ends of the platen.

Abstract: A guide for directing a print head in a printing device parallel to a platen, the guide being constructed of a unitary extrusion of a metallic material having two guide rails joined by a thin web of material. The structural arrangement of the guide offers a high resistance against bending so that a constant predetermined distance can be maintained between the print head and the platen.

Abstract: 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.

Abstract: A cartridge for an endless band printer ribbon includes a chamber for storing the ribbon in a convolute therewithin. One or more segments of the ribbon are maintained exteriorly of the cartridge to overlie and close the open end of a corresponding depression(s) formed in the cartridge's periphery to form a protrudent member-receiving compartment. The number of depressions corresponds to the number of protrudent ribbon guides (rollers, posts, etc.) in the printer. The protrudent member-receiving compartments are positionable so that their corresponding guides may be simultaneously received therein. After such reception, the cartridge is moved away from the guides, which thereupon engage and withdraw the ribbon from the convolute by unwinding it until the cartridge is mounted to the printer and a portion thereof is properly adjacent a printing location on a platen. The cartridge may also contain a one-way clutch to effect unidirectional ribbon movement and a ribbon re-inker.