International Business Machines Corporation

William J Thornhill

Billy D Purcell

Edward E Toutant

Robert H Sweat, Jr

John A Elder, Jr

Robert L Bullock

John N Cassell

Benjamin G Pastrick

A ribbon cartridge is provided to be used in a high speed impact printer having means for driving only one reel in the ribbon cartridge, the take-up reel. The ribbon cartridge comprises a cartridge housing having an open end, and supply and take-up reels rotatably mounted in said housing. The supply reel supports an inventory of unused ribbon web which runs from the supply reel to the take-up reel. The rib is mounted in the cartridge housing facing the open end in a position closer to the supply reel than to the take-up reel. The printer into which the ribbon cartridge is to be inserted contains driving means for driving only the take-up reel. The printer receiving means into which the cartridge is to be inserted includes a stop element disposed so as to block the rib to stop the engagement of the cartridge and the receiving means when the cartridge is being inserted in a direction towards the undesirable engagement of the drive means with the supply reel rather than with the take-up reel.

Single pass ribbon cartridge for impact printers having means to prevent

In an impact printer including a print wheel having a plurality of selectable character type bearing elements for respectively printing a plurality of characters, said print wheel being rotatable for selectively positioning selected type elements in successive print positions, impact means impellable against the selected elements to drive said elements against the printing medium and means for impelling the impact means against said selected type element, the present invention provides the improvement comprising means for sensing the flight time of the impelled impact means until impact by sensing variations in velocity of said impact means and means responsive to said sensed flight time for controlling the impelling means to vary the flight time. In accordance with another aspect of the present apparatus, means are provided for detecting the coincident engagement of the impact means with a type element by also sensing the velocity of the impact means after the impact means has reached a predetermined coincident engagement position.

Impact printer hammer flight time and velocity sensing means

A bounce dampening system reduces switch actuator bounce when the actuators are restored to their home position. Included are selection interposers, one of which is selectively driven to thereby effect motion of selection bails and corresponding switch actuators. A reverse interposer is simultaneously driven. A spring restores the reverse interposer after the actuation cycle thereby carrying the bails and switch actuators to their home position. The return spring and the mass of the reverse interposer prevents actuator bounce and insures a timely return of the actuators.

Bounce dampening system for switch actuators

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Austin, TX, United States of America

William J Thornhill