International Business Machines Corporation

Lexmark International, Inc.

William L Dollenmayer

James A Craft

James J Molloy

James Philip Harden

Frank Marion Hughes

An electrophotographic printer (11) having a base (13) and a top (12), the top (12) being pivotable about an axis (23) between a closed position and an open position. The printer (11) receives a supply cartridge (14) on a shelf (22) which is pivotable about the same axis (23) as the top (12) of the printer (11). A counterbalance spring (34) helps to support the shelf (22) and the cartridge (14) below the top (12) of the printer (11) and above the printer base (13) when the top (12) of the printer (11) is in its open position. When the top (12) of the printer (11) is closed, the cartridge (14) is urged into a position adjacent the printer base (13) and locked into an operative position.

Electrophotographic printer and cartridge arrangement

A pivoting means for pivoting back and forth a mechanical load such as a print hammer about a given axis and within a low amplitude angle includes two elongated leaf springs. The leaf springs are located in planes at a given angle with respect to each other but both planes being perpendicular to the plane of pivotation of the mechanical load. A frame fixed relative to the pivotable mechanical load is used for attaching the extremities of both elongated leaf springs. The mechanical load is attached to both leaf springs equidistant from their attached extremities. A power source pivots the mechanical load from its rest position to its work or print position causing the two leaf springs to be flexed in torsion. The torsion flexing generates a return torque for self restoring the mechanical load back to its original position.

Self restoring pivoting means and print hammer using same

A serial impact printer 11 includes a frame 15 mounted drive motor 47 coupled to a print wheel 31 to effect rotation thereof. The print wheel 31 is mounted on a movable print carrier 29 which serially moves from print position to print position along the print line. The motor 47 is coupled to the wheel pulley 51 of the print wheel 31 through a belt 49 which is wrapped about two idler pulleys 57 and 59 located on a sub-carrier 61. The sub-carrier 61 moves one half the distance of the print carrier 29 so that during escapement motion of the print carrier 29, the belt 49 imparts no rotary motion to the wheel pulley 51 and hence to the print wheel 31. The print carrier 29 may be clamped by clamp 77 to the belt 49 to effect the return motion thereof. The motor 47 is also coupled through a clutch 127 to the line feed apparatus of the platen 23.

Shared character selection, escapement and line advance system for

A printwheel 20 for a daisy wheel printer 10, the printwheel 20 including a hub portion 23 and a plurality of radially extending, deflectable petals 21 projecting therefrom. The petals include a pad or tip 24 thereon with print forming indicia on one surface 24a thereof and a striking surface on the opposite surface 24b thereof adapted to be struck by a print hammer 30 to move the indicia against paper 16 or other print receiving medium. The striking surface 24b comprises first and second, axially projecting inclined surfaces 25, 26, each of the inclined surfaces being disposed, with respect to the other, to subtend an angle `AN` therebetween in plan. The striking surface 24b is disposed in such a manner as to be engaged by complementary inclined surfaces 32, 33 on the print hammer 30 whereby angular misalignment between the hammer 30 and the petal 21 may be compensated for by lateral deflection of the petal 21 to effect a detenting between the complementary inclined surfaces 25, 26 of the petal 21 and the print hammer 30.

Printwheel detent

An impact printer utilizes a single print hammer which is loaded with a selected type chip transferred from a rotatable carousel cartridge containing plural type chips. A single solenoid motor is energized to effect chip transfer, the loading of a spring to effect subsequent return of the chip to the cartridge, and the loading of an energy storage spring utilized to power the print hammer toward a platen. Completion of the chip transfer to the print hammer releases the print hammer to be powered by the storage spring until the solenoid motor is de-energized. The solenoid armature provides a reaction force to the storage spring only during solenoid energization. The duration of solenoid energization thus controls the impact force of the print hammer and is varied in accordance with the character area of the selected type chip and with the desired print density. An interlock latch prevents return motion of the type chip positioning and transfer mechanism during printing and during return motion of the print hammer. A restraining latch restrains the print hammer in its chip receiving position until the chip transfer to the print hammer is completed. The latching member of this latch is resiliently urged to restore the type chip to the cartridge upon return of the print hammer to its chip receiving position. An additional mechanism insures clearance of the latch member from the cartridge upon return of the type chip thereto.

Print hammer actuating device

A print hammer for a high speed impact printer using a movable type-face-carrier, e.g., a rotatable printwheel. The print hammer is designed to enable rotating the printwheel for character selection purposes during the return stroke of the print hammer from impact position back to its rest position. While the print hammer moves in a plane perpendicular to the printer platen, back to rest position, pivotal and cam means cooperate to lift the hook shaped hammer head up and over the printwheel, therefore continuously clearing the path of said rotatable printwheel.

Print hammer for high speed impact printer

An automatic typefont loader is sequenced to change the printwheel typefont of a printer. An elongated rack supports plural picker holders along its length and is normally located beneath the platen of the printer. Typefonts to be exchanged are held by the picker holders. During an exchanging sequence, the typefont carrier which is positioned along the platen to effect printing at discrete printing positions is positioned to a discrete printing position adjacent an empty picker holder for a typefont unloading operation. The elongated rack is then elevated so that the empty picker holder contacts the typefont. The typefont is removed from its carrier by moving the typefont carrier perpendicular to its normal motion. The picker holder rack is then withdrawn and the now empty typefont carrier is positioned to a second discrete printing position adjacent a selected typefont located on a picker holder. The picker holder rack is elevated and the typefont carrier moves toward the selected picker holder to retrieve a typefont. The operation is completed with the withdrawal of the rack to its normal position beneath the platen.

Automatic typefont loader

Two coaxially mounted spoked print wheels form a single printing element of a serial printer. Each wheel contains plural spokes having print characters thereon and a selected spoke is driven by a hammer to impact paper on a platen thereby effecting printing. Each wheel has a gap or window between two spokes of sufficient size to allow hammer or spoke entry. In operation, the window of one wheel and the selected spoke of the other wheel are rotated to the print position. The hammer is actuated to effect printing. The distance between the hammer and the selected spoke is maintained constant when shifting from wheel to wheel by shifting the wheel combination axially along its axis of rotation. The printing element is advanced relative to the platen and the platen is indexed to effect serial line printing. The two print wheels can readily be removed as a unit from the printer and replaced for type style interchangeability.

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Versailles, KY, United States of America

William L Dollenmayer