Abstract: In a printing device including rotatable character wheels having type characters on the surface thereof and a selection mechanism for selectively bringing a character to a printing position, a drive means is provided for moving the selection mechanism. Coupling between the drive means and the selection mechanism is effected by an electro-magnet, size and power requirements for the electro-magnet being reduced by the fact that the electro-magnet functions only as a coupling means and not as the drive means itself.

Abstract: A miniature printer especially for use in a small calculator or the like, of the type in which a plurality of character wheels are carried on a rotating drive shaft. The speed of rotation of the drive shaft can be varied so that its speed during character selection is different from that during the resetting of the character wheels.

Abstract: In a printing device, printing type rings are mounted on a rotatable, grooved shaft. Each ring has associated therewith a pawl and a selecting mechanism for engaging the pawl with a selected groove on the printing type ring whereby a selected character on the ring may be brought to an inking position and then to a printing position. Retraction of the pawl by said printing mechanism disengages the pawl and allows the ring to reach a rest or stand-by position.By the use of the retractable pawl a printing device is provided in which only those rings which are about to be used for printing are rotated, and the load on the inking mechanism is greatly decreased. The printing device may therefore be decreased in size and in energy consumption and the wear on the various members of said device is greatly decreased.