Two-color shifting device for printing ribbon

A two-color shifting device for a printing ribbon, in which when a notched pinion provided with feed gear and intermittent feed gear formed alternately thereon in a circumferential direction thereof is pushed by a printer in order to be moved to a two-color shifting position against a compression spring, a two-piece gear formed on a feed wheel to be rotated by a motor is brought into mesh with said feed gear and intermittent feed gear in turn, respectively, to cause said notched pinion to make a feed-rotation, so that a switch cam formed on said notched pinion switches a ribbon cassette between an upper position and a lower position to effect a two-color shifting, wherein said two-color shifting device for printing ribbon is characterized by:

• said feed gear and intermittent gear axially spacedly arranged alternately on the peripheral surface of said notched pinion, a two-piece gear formed of a notched gear meshable with said feed gear and an intermittent gear meshable with said intermittent notched gear being arranged on both front and rear sides of the peripheral surface of said feed wheel, with a mesh-prevention side thinner than a distance between said feed gear and said intermittent feed gear being left at a center thereof, when a normal printing is effected, said feed gear being in contact with said mesh-prevention side to prevent the feed gear from meshing with said notched gear, however, when said notched pinion is moved to said two-color shifting position, said feed gear and intermittent feed gear being brought into mesh with said notched gear and intermittent gear, respectively, so that said notched pinion makes a feed-rotation.