Abstract: A keyboard for typewriters or similar machines has a key support, switching contacts and key push rods, each of which is acted upon by a spring. The design of the few individual parts assures their simple manufacture (extruded parts and a stamped part) as well as an assembly just as simple and therefore automated, and, if desired, even without screws or aids of that type. Activation of the individual keys takes place with satisfactory tactile feedback and without undesireable vibrations.

Abstract: An arrangement for monitoring the operation of the ink ribbon (2) of an ink-ribbon magazine (1) for electromechanical print units or print mechanisms comprises contacts (12,6) on the ink-ribbon magazine (1) on either side of the ink ribbon's path (4) and intended to lie against the ink ribbon (2), and opposite contacts (7,8) on the print unit which, when the ink ribbon magazine (1) is inserted, are in contact with the contacts (21,6) of the later and are connected electrically to a function or malfunction indication (10). When holes or tears occur on the ink ribbon (2), the contacts (12,6) on the ink-ribbon magazine (1) come in contact with one another and thereby set off a signal which can be used to switch off the print unit and/or for a malfunction indication.

Abstract: An ink ribbon unit for printers in which the inking roller is selectively brought into engagement with the ribbon thereby to avoid over-inking.

Abstract: A replaceable cartridge containing an endless loop ink ribbon for use in printing units. The ribbon storage area inside of the cartridge is configured to guide the ribbon so that a large amount of ribbon may be stored in the allowed space while retaining favorable ribbon feed characteristics. The ribbon is guided by ledges formed on the inside surfaces of the cartridge between the ribbon inlet and outlet openings. The cartridge is to be constructed in halves and is designed with such symmetry that the halves are identical and so may be produced by the same tool or machine.

Abstract: A cassette-type ink ribbon device for a printer wherein the inked ribbon is carried in a throw-away magazine operatively disposed within and wholly independent of the cassette body. The cassette body carries all of the drive components and, hence, replacement of the magazine revitalizes the cassette at minimum expense.