DIRECT KEYBOARD CONTROLLED CHARACTER SELECTION RACK SHIFTING DEVICE FOR A SINGLE ELEMENT TYPEWRITER

摘要

Device for shifting a bifurcated character selection rack (12) between a first position and a second position, thereby engaging alternate portions (14, 16) of the rack with a pinion (18) controlling the rotation of the typehead (10) of a typewriter. The rack shifting mechanism (58, 60, 46, 32) is controlled by a direct link (62) 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 keylever and link displacement to a relatively small rack displacement. The rack shifting mechanism translates the rack to engage the alternate rack portion with pinion (18) thereby reversing the rotation of the pinion and allowing characters to be selected from the opposite hemisphere of the type element in response to a character selection input.