Printing and/or correcting device for printing machines

摘要

The printing and correcting device is applied to a daisywheel printer and comprises a frame supporting a cartridge for a typing ribbon and a correcting ribbon arranged below the typing ribbon. The frame is able to swing as the result of operation of an electromagnet, from a rest position providing visibility of the print, to an intermediate position for printing the characters. A second electromagnet raises the frame through a greater length of travel in order to position the correcting ribbon in front of the printing point. A rotating electromagnet causes automatic unidirectional advance of the typing ribbon after each character has been printed. The correcting ribbon is wound between two spools and its motion is provided by means of a pawl which engages with a gear wheel for driving the spool only in the case where the path of travel of the frame is greater than that which relates to positioning of the typing ribbon. A paper finger in the form of a sheet of limited thickness is provided with a cut out portion corresponding to the printing point, and with a guide in the form of a leaf spring for guiding the two ribbons adjacently to the typing paper when they are being raised and for preventing unwanted contact by these.