Alternative Pawl-and-ratchet Drive Including Ratchet Directly Connected To Spool Or Spindle Patents (Class 400/220)
  • Patent number: 4502803
    Abstract: The ink ribbon feed mechanism comprises a pair of spool shafts adapted for carrying ribbon spools, a pair of feed pawls selectively engaged with one of the ratchet wheels on said spool shafts for imparting intermittent rotation to the spool shafts, and a reverse mechanism for changing the engaging state of the feed pawls relative to the ratchet wheels. The reverse mechanism includes a first member movable from one to the other direction through a connecting member which is adapted to rotate in unison with the ratchet wheel in dependence upon an operation of a sensor for indicating that reversal of the ribbon take-up direction is required, a second member movable from one to the other position after travel of the first member through a predetermined distance, for changing the engaging state of the feed pawl, and first and second detent members being provided for positioning the members in their two positions.
    Type: Grant
    Filed: February 26, 1981
    Date of Patent: March 5, 1985
    Assignee: Brother Kogyo Kabushiki Kaisha
    Inventor: Shigenori Hattori