Abstract: A platen for typewriters or similar machines comprising a platen tube with a resilient outer cover and having stub shaft assemblies press fitted into each end. Each assembly comprises a circular end piece having a central bore into which a stub shaft is press fitted, and a circular plate having a central depression into which one end of the stub shaft is press fitted. The arrangement allows for a platen construction of few easily produced parts which can be easily assembled to provide an inexpensive assembly.

Abstract: Function controlled raising and transporting mechanism for the selective control of a print ribbon or correction tape by means of a power drive and freewheeling clutches operative to effect print ribbon or correction tape transport incident to carriage motion in print direction only. In certain commanded functions such as spacing, tabulating, etc., both the print ribbon and correction tape transports are disabled by moving output elements of the freewheeling clutches to intermediate clutch disabled positions to thereby realize optimum utilization of the ribbon and tape capacities.

Abstract: A ribbon cassette is provided with a rotatably mounted ribbon supply spool whose flange has markings, angularly spaced according to ribbon type, which are adapted to be successively sensed as ribbon is incrementally drawn off a supply spool to provide signals from which the type of ribbon in the cassette can be identified and the feed increments therefore determined, and information regarding the supply of ribbon remaining on the spool, end of ribbon and ribbon jams may be derived in a programmed control unit. The ribbon cassette further comprises a two-armed lever pivotally mounted in the cassette housing, having first and second lever arms which engage teeth on the edge of the spool flange when the two-armed lever is in a first end condition and a second end condition respectively.

Abstract: A code generated by a keyboard or external data source is first converted to an ordinal number code which is processed by first and second algorithms to generate a typing force index and a character type location identifier respectively. The typing force index is used as a variable in an equation whose solution provides typing force information, and the character location identifier is used to calculate character type location information. The information is utilized to position a selected character on a print wheel and to print the selected character with a force depending on the area of the character.

Abstract: An arrangement of a paper guide trough supporting pressure rollers to guide paper about the platen of a typewriter is used in conjunction with a platen having an elastic bearing to effect an automatic adjustment of the platen according to the thickness of paper inserted to maintain the same printing plane without additional components.

Abstract: A ribbon cassette for typewriters is provided with an end-of-ribbon signaling device which takes the form of a switch comprising a contact web on a ribbon tensioning lever associated with the supply spool in the ribbon cassette and two contact pins provided in the machine. The contact web is adapted to bridge the contact pins signaling end of ribbon when the ribbon supply is used up.

Abstract: A method and apparatus for indexing the print hammer of typewriters or the like having a carriage supported type matrix positionable in X-Y directions to present a selected character for printing wherein the matrix positioning motor is used to index the hammer in advance of matrix positioning movement.