Ribbon feed device

Claim 1

A ribbon feed device for a recording apparatus comprising: drive means for rotating about a first shaft in clockwise and counter-clockwise directions in connection with a reciprocating motion of a carriage of said recording apparatus, said drive means including a drive gear rotatably supported by said first shaft and having teeth disposed around an outer periphery thereof; ribbon feed means for feeding an ink ribbon rotating about a second shaft positioned parallel to said first shaft, said ribbon feed means including a gear having first and second concentric circular toothed surfaces having different pitch circle diameters, said first toothed surface being externally geared and said second toothed surface being internally geared, a space between said first and second shafts being smaller than a sum of radii of said drive gear and said ribbon feed means so that a face portion of said ribbon feed means overlaps with a face portion of said drive gear; and a planetary gear positioned between said first toothed surface and said second toothed surface of said ribbon feed means and automatically rotating about said first shaft in a direction of said drive means for transferring rotating power directly from said drive means to said ribbon feed means by meshing with said ribbon feed gear means at said first toothed surface during the rotation of said drive means in said clockwise direction, and meshing with said ribbon feed means at said second toothed surface opposing said first toothed surface when the rotation of said drive means is in said counter-clockwise direction, so as to cause said ribbon feed means to always rotate in the same direction irrespective of the rotational direction of said drive means.