Abstract: Keyboard generated signals are digitally encoded and converted to varying voltages for application to a coil for generating magnetic forces. The magnetic forces act on a spring mass system including a type disc to rotate the type disc to a selected angular position. The rest position of the disc at any selected angular position is established when the applied magnetic force and the force of an oppositely acting spring reach equilibrium condition. The spring stores or releases energy according to whether the applied magnetic force is greater or less than the existing spring force. The parameters of the system are so chosen that movement from one angular position of rest to another is smoothly accomplished in a given time.

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: A method and apparatus for positioning a type disc in a balanced force system wherein applied selective forces to effect angular positioning movement from an old to a new position are brought into equilibrium with opposing spring forces. Electronic positioning controls are provided to generate forces for application at different times during a positioning movement whereby positioning movement from one equilibrium position to another is accomplished without damping and without overshoot in the shortest optimum fixed time and with the least expenditure of energy. The electronic positioning controls first apply a force corresponding to a new position and then, midway of the angular positioning distance between the old and the new position, apply a force corresponding to the old position to decellerate positioning movement until natural oscillation about the old position carries the disc to the new position at which time the force corresponding to the new position is again applied to hold the new position.

Abstract: A daisy wheel print element provided with hammer energy absorbing formations to obtain substantially uniform print density for different print area types.

Abstract: A daisy wheel typewriter wherein wheel positioning to present a character for printing and hammer actuation to effect printing of a selected character are electronically operated in response to keyboard generated signals. Functions associated with a printing action, e.g., ribbon lift, ribbon feed, and carriage spacing, are, however, operated mechanically in synchronism with the electronics by a timing disc driven by a print cycle function actuating shaft. Non-printing service functions are also operated mechanically by conventional powered mechanisms responsive to keyboard generated signals.