公开(公告)号：CA1122144A

公开(公告)日：1982-04-20

申请号：CA352801

申请日：1980-05-27

Applicant: IBM

Inventor： MCDANIEL ROBERT F ,  PREWARSKI MIKE ,  RAMEY LEONARD D

IPC: B41J1/60 ,  B41J7/50 ,  B41J7/52 ,  B41J25/24

Abstract: DIRECT KEYBOARD CONTROLLED RACK SHIFT DEVICE FOR A SINGLE ELEMENT TYPEWRITER 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. LE9-77-018