Abstract: Mechanism to raise and transport print and correction ribbons in typewriters and similar machines as a function of the direction of a rotation of a motor. The required motions are brought about by means of a cam wheel containing different cams and by appropriate cam followers, and provision is made to maintain ribbon raised to the typed line level so that during rapid printing only transport steps need to be carried out. It is also possible with the mechanism to effect transport steps of different size, to meet the requirements of the ribbon type used.

Abstract: A typewriter having a thermal print head defining an array of print elements and a thermal print ribbon, both of which are supported on a carriage movable relative to a platen, is provided with a control system which responds to a character print command to move the print head into controlled pressure contact with the platen and to engage a substantially play free clutch for coupling carriage movement initiated by a print command to advance ribbon opposite the direction of carriage movement whereby relative movement between said ribbon and platen is avoided during printing.