Bar code printer with automatic mechanical parity

A printing device to print codes corresponding to characters comprising:

• a plurality of code printing wheels, each printing wheel having a series of codes and each code corresponding to a character;
• a plurality of operator movable selector means, each selector means connected to its respective code printing wheel and being capable of being positioned to correspond respectively with a character, each selector means serving as means for incrementing or decrementing its respective printing wheel in response to incrementing or decrementing the selector means;
• selector interlock means for preventing more than one of the selector means from being moved at any one time;
• parity character generation means comprising:
• a parity code printing wheel having a series of codes with each code corresponding to a parity character, the parity wheel mounted on a shaft,
• mechanical connecting means connected to and between the parity code printing wheel and the selector means,
• the movement of the selector means causing a corresponding directly proportional movement in the mechanical connecting means and in turn proportional rotational movement in the parity code printing wheel,
• whereby a single unit of movement in the selector means causes a corresponding single unit of rotational movement in the parity wheel.