Abstract: A device to facilitate the changing of disc-shaped type carriers in typewriters or printers includes a lever operated device to push against the type disc and to press it off its shaft. A basket is provided to catch the type wheel after its disengagement from the shaft to prevent it from falling into the interior of the machine.

Abstract: Mechanism responsive to discrete character signals is provided for selectively rotatably positioning a type disc clockwise or counterclockwise from a home position to present the selected character on the type disc for printing. The mechanism comprises a driven lever pivoted intermediate its ends which is cycled about its pivot in response to each character selector signal from a keyboard. When cycled, one of the arms of the driven lever is adapted to drive an associated rocker from a rest position and through its other arm is adapted to allow an associated rocker to be driven from a rest position. The movement of the rockers, the magnitude of which is determined by interposers representative of characters which are selectively interposed between associated arms and rockers at various distances from the pivot of the driven lever, controls the pivotal movement of associated frame supported crank levers spring urged against the rockers.

Abstract: Printing members comprising a mosaic printing head are driven by flexural bending elements which are electrically actuated to produce a desired printed pattern. The bending elements may take the form of piezoelectric strips or diaphragm pieces which are supported by bearings located at nodal oscillation points of the elements. The printing members when actuated protrude from a bore in one end of a printing head housing. The printing head housing is mounted for transverse movement along guide rails.

Abstract: A plurality of printing needles forming an array are mounted in a printing head and are periodically driven to impact a printing ribbon onto a recording medium. The printing head contains a brake for each needle so that selected needles can be prevented from striking the printing ribbon allowing the formation of a desired character matrix pattern on the recording medium. Each brake may be driven by a piezoelectric element.

Abstract: A mount for a consumable electrode printer comprises a member which slidably receives an array of consumable electrodes which are biased to a printing position, a clamp for gripping the electrodes to prevent the sliding thereof, and a release for the clamp to allow the biased electrodes to advance to a printing position.