ESCAPEMENT MECHANISM AND BACKSPACE MECHANISM FOR A MOVING PAPER CARRIAGE TYPEWRITER HAVING DUAL PITCH CAPABILITY

摘要

ESCAPEMENT MECHANISM AND BACKSPACE MECHANISMFOR A MOVING PAPER CARRIAGE TYPEWRITERHAVING DUAL PITCH CAPABILITYAbstract of the DisclosureA mechanism which will function to allow the escapementof the carriage of a typewriter in one of two predeterminedescapement pitches and be capable of backspace operationfrom a single backspace input for both pitches regardlessof which is disclosed. Escapement ratchets for the twoselected pitches are combined, together with a backspaceratchet. Each of the escapement ratchets are engageableby an escapement pawl and the engagement of a pawl with aparticular ratchet will determine the pitch within whichthe escapement system will function. A backspace ratchetis combined with the escapement ratchet and fixedlyattached thereto to provide the backspace drive. Thebackspace ratchet is selectably engageable by thebackspace pawl for causing rotation in the oppositedirection of that normally utilized for escapement. Allmotion of the escapement ratchet or backspace ratchet istransmitted through a pinion mounted to the ratchetassembly and, in turn, is transmitted to the papercarriage rack.