Abstract: A printing device having a detachable printwheel coupling means which includes a motor driven drive plate which is formed with a cantilevered spring finger and an aligning slot disposed on the side opposite the spring finger. The spring finger carries at its free end an alignment pin which automatically engages a radially offset cam surface located in a recess formed in the hub of a printwheel when the drive plate rotates relative to the printwheel. The printwheel hub also includes a drive pin which engages the aligning slot when the printwheel and drive plate abut under the urging of a pressure plate. The device inhibits angular and radial movement between the drive plate and the printwheel.

Abstract: An arrangement for assuring ink ribbon and correction tape compatibility in a device which utilizes a first cassette having an ink ribbon therein and a second cassette having a correction tape therein in the operation thereof, the arrangement including engaging formations located on the first and second cassettes which ensure that the ink ribbon and correction tape are functionally compatible with each other when the respective cassettes are inserted in the device such as, for example, functional compatibility between a single-strike ink ribbon and a lift-off correction tape, or functional compatibility between a multiple-strike ink ribbon and a cover-up correction tape.

Abstract: A means for assuring ink ribbon and correction tape compatibility in a device which utilizes a first cassette having an ink ribbon therein and second cassette having a correction tape therein including a switch means in the device that controls the on-off condition of the device, and means located on one of the cassettes which will activate the on-off switch only when the device contains an ink ribbon in the first cassette which is functionally compatible with the correction tape in the second cassette, such as, for example, functional compatibility between a single-strike ink ribbon and a lift-off correction tape, or functional compatibility between a multiple-strike ink ribbon and a cover-up correction tape.

Abstract: A tape cassette has a sensing arm pivotally mounted therein biased against a correction tape on a take-up spool for sensing the amount of correction tape thereon. A correction tape feed mechanism mounted in a typewriter has a metering post for engaging the sensing arm at varying locations to cause the correction tape feed mechanism to feed the correction tape at substantially equal amounts regardless of the amount of correction tape on the take-up spool.

Abstract: A character display is pivotably mounted on an electronic typewriter for pivotable movement from an open position for viewing the character display to a closed position for covering the keyboard. The character display has a pivot axis in alignment with a rotatable axis of the platen. A structure for pivotably mounting the character display includes a spring operable to dampen the pivotable movement of the character display near the closed position. A brake pad combined with the dampening spring holds the character display in manually selected positions near the open position. A paper support which covers a platen and an adjacent open area is combined with the character display located in the closed position to provide a cover for the typewriter.

Abstract: The present invention is a typewriter lid actuated printing element homing device which uses a single switch for assuring that the printing element is engaged and maintained in its home position without any accompanying noise after the printing element is inserted, and also for assuring that the printing element is in its correct escapement position after the printing element is inserted. When the typewriter lid is closed, the carrier escapement position and the carrier motor phase is entered into memory. A latch member controlled by an actuator engages a notch in a flange of a rotating printing element drive gear for establishing the home position of the printing element. When the latch member engages the flange, the printing element drive gear motor is deenergized, stopping rotation of the drive gear, and the noise which would otherwise be caused by the print element drive motor continuously trying to rotate against the latch member is eliminated.

Abstract: The present invention includes means for maintaining a printing element in its home position without any accompanying noise and for thereafter moving the carrier to its left margin position after the power switch is turned on. A latch member controlled by an actuator engages a notch in a flange of a rotating printing element drive gear for establishing the home position of the printing element. When the latch member engages the flange, the printing element drive gear motor is deenergized, stopping rotation of the drive gear, and the noise which would otherwise be caused by the print element drive motor continuously trying to rotate against the latch member is eliminated.

Abstract: A single solenoid is connected to a ribbon feed mechanism which is selectively operable either to feed a print ribbon or to lift and feed an error correction tape. A print hammer solenoid is operable to condition the ribbon feed mechanism either for feeding the print ribbon or lifting and feeding the error correction tape. To feed the print ribbon, an electronic circuit energizes the print hammer solenoid before energizing the ribbon feed solenoid in response to depressing a character key. To lift and feed the error correction tape, the electronic circuit energizes the print hammer solenoid after energizing the ribbon feed solenoid in response to depressing a correction key.

Abstract: A linespacing apparatus includes a slip clutch assembly which is driven by an electric motor. The slip clutch assembly includes a face cam which drives a linkage which, in turn, indexes a platen in order to linespace the platen. The face cam includes an abutment portion which abruptly halts the motion of the linkage and the slip clutch assembly prevents bounce or recoil of the linkage thereby promoting smooth operation of the apparatus. The linkage may be adjusted by an operator to vary the amount of rotation of the platen during each operating stroke of the linkage.

Abstract: A direct connection provides coupled movement from a keylever to an interposer of a simple key action in a typewriter. The connection includes an abutment integrally constructed on the keylever inserted within a recess on the interposer to effect movement of the interposer when the keylever is caused to move. Depression of the keylever pushes the interposer downward against a pawl that will engage a rotating power roll to cause initiation of a print movement of a typebar. The keylever while being restored by an underlying spring, will then pull the interposer upward to rest. The keylever and interposer are in planar alignment that is maintained by having the connection contained within a slot of a support member in the typewriter.

Abstract: An interposer in a typing machine key action is supported by an arcuate spring and a shelf. When a key lever bears against the arcuate spring to release the interposer from the shelf, the arcuate spring snaps the interposer against a pawl that engages a power roll to initiate a typing operation. Potential energy is restored to the arcuate spring as the key lever lifts the interposer back to rest position. The arcuate spring serves as a support and frictionless pivot for the interposer and biases the interposer against the shelf while providing energy to impel the interposer against the pawl.

Abstract: A typebar support for low cost typewriters includes an arcuate segment supported on a frame where a plurality of typebars are pivotally mounted. The free ends of the typebars are supported by an arcuate support. The support is rockably suspended on the frame by a pair of arms extending from the ends of the support to the frame. The arms are biased upward by a pair of springs and limited in its upward movement by an abutment mounted on the segment. As a typebar returns to rest after a print cycle has been completed, the energy accumulated in the typebar during flight is partially dissipated when it impacts on a yieldable pad on the typebar receiving edge of the support. The remaining energy is absorbed by the rocking motion of the support. The energy dissipation by the yieldable pad combined with the energy absorption by the rockable support results in a typebar support that effectively reduces typebar rebound and the accompanying problems.

Abstract: A changeable type element for typebars of a typewriter is disclosed comprising a U-shaped member having a pair of walls spaced from one another by a connecting type face. The type element is multipositional within the typebar segment of the typewriter. A camming means is pivotally supported between the spaced walls. A spring, attached to the camming means biases the camming means into locking engagement with the typebar when the type element is assembled on the free end of the typebar. The spring compensates for any wear on the camming means to prevent the camming means from disengaging from the typebar. The type element is thereby prevented from flying off the typebar when the typebar is in flight or from becoming loose from repeated printing operations.

Abstract: A keylever touch control mechanism for typewriters includes keylevers mounted on a common pivot which spans the distance between the spaced side frames of the typewriter. The keylevers are supported in their rest position by a plurality of underlying leaf springs. Keylever touch is controlled by the amount of force exerted on the underside of the keylevers by the leaf springs. A spring loaded pivotal bail having rigid extensions underlying the leaf springs pivots into abutment with the springs to vary the tension of the springs. A detented control mechanism is coupled to the bail to pivot the bail extensions into and out of abutment with the leaf springs. When the bail extensions are pivoted into abutment with the leaf springs and a keylever is depressed, the force required to overcome the biasing force of the spring loaded bail extensions to depress a keylever is increased and the keylever touch is correspondingly increased.