Error correcting typewriter

Claim 1

A typewriter having key controlled means for typing characters at a relatively movable print point, a unidirectional inked ribbon drive, a unidirectinal error correction ribbon drive, a single ribbon elevating means, means for supporting an error correction ribbon and an inked ribbon for driving engagement with associated ribbon drives and for movement past said print point through said single ribbon elevating means, means for enabling one and disabling the other of said ribbon drives to move either said error correction ribbon or said inked ribbon past said print point incident to typing, said ribbon elevating means including throw selecting means positionable to condition either said inked ribbon or said error correction ribbon for elevation in front of said print point incident to typing, escapement control means operative incident to and following typing, interposer means for precluding, when positioned, operation of said escapement control means, an error key lever, and error key lever controlled mechanism operative, when and for as long as said error key lever is held depressed, on said means for enabling one and disabling the other of said ribbon drives to enable the error correction ribbon drive and disable the inked ribbon drive, to position throw selecting means to condition said error correction ribbon for elevation opposite said print point incident to typing, and to position said interposer means to preclude operation of said escapement control means incident to typing.