International Business Machines Corporation

Lexmark International, Inc.

Robert F McDaniel

James P Wang

John O Schaefer

Darell Dean Cronch

Mike Prewarski

Freddie M Lawson

Leonard D Ramey

Word processor system unit

Data memory module

A device is disclosed for shifting a bifurcated rack from one position to a second position, thereby engaging alternate sides of a bifurcated rack member with a pinion in a spacially fixed position. The rack shift mechanism is controlled by a direct link to the keyboard of the typewriter which responds to movement of a shift key lever. The mechanism performs a force multiplication and, at the same time, a displacement division function to reduce a relatively large key lever and link displacement to a relatively small rack displacement with a correspondingly higher force factor. The force multiplication linkage translates the rack of the rack/pinion pair to engage the alternate portion of the rack, thereby reversing the rotation of the pinion and allowing the selection from the opposite hemisphere of the type element in response to a selection output.

Direct keyboard controlled rack shift device for a single element

Disclosed is a mechanism for shifting the rack of a selection mechanism for a single element printer from one portion to another in timed relationship to the translation of a barrel cam which provides the necessary mechanical input to control the amount of rotation of the typehead. The control of the rack shift mechanism is a cam arrangement operated in timed relationship with the translating barrel cam to provide for the shifting of the rack at the beginning of each print cycle, if necessary, and the retaining of the rack in its shifted position at the completion of the cycle, thereby eliminating the necessity to provide for the time required to shift the rack back to its home position at the end of the cycle. The elimination of the restore operation of the rack provides more time during the cycle to operate the selection mechanism and accomplish printing or conversely provides for a smaller amount of time being required for the necessary functions thereby providing the capability of operating the remainder of the mechanism at a faster rate.

Printer with non return to home rack shift selection mechanism

Growing community of inventors

Paris, KY, United States of America

Robert F McDaniel