Abstract: An assembly for positioning a print head so as to transfer ink from an ink ribbon to a printing medium positioned on a movable platen adjacent to said ribbon supports the print head on a rocker member which enables the head to be swung between a print position wherein it engages the ink ribbon and a feed position wherein the head is spaced from the ribbon enabling ribbon to be moved. The rocker is rocked to move the head between its two positions by a rotary cam driven by a small low-power electric motor. When the cam engages the rocker member at selected angular positions, the head is maintained in its retracted feed position; otherwise, the head resides in its print position. The assembly also includes provision for detecting the angular position of the cam so as to produce signals to facilitate repositioning the cam and head promptly.

Abstract: A user-friendly ribbon cartridge to house and to facilitate handling a wide thermal transfer ribbon for a thermal color printer is composed of first and second casing sections which define a slotted let-off tube and a slotted take-up tube and turnbar. A pair of casing end pieces connect the corresponding ends of the casing sections so that they are juxtaposed with their axes parallel to one another so as to define a plane and the turnbar is spaced parallel to that plane so that a stretch of ribbon wound about cores rotatively mounted in the tubes can extend out through the tube slots and over the turnbar creating a large unobstructed planar ribbon area that is accessible from both sides for printing. A handle and latch member integral to one of the end pieces facilitate positioning the cartridge properly in the associated printing apparatus and locking it in place during printing.

Abstract: A mechanism for clamping the leading edge of a sheet to be wrapped around a printing drum for printing in a plurality of colors includes a clip that is movably mounted in the drum so that it can be moved between an open position and a clamping position, the clip being biased to its clamping position. One or more deflectable cams are positioned adjacent to the drum for engagement by the clip. When the drum is rotated in its direction for printing successive colors on the sheet, the clip deflects the cam and remains in its clamping position. However, when the drum is rotated in the opposite direction to discharge a printed sheet, the clip is engaged by the cams and wedged thereby to its open position thereby releasing the printed sheet. The mechanism also includes provision for automatically discharging the printed sheet from the drum to a discharge path adjacent to the drum when the clip is opened.