Power operated tyepwriter with means for error correction

Claim 1

In a power operated typewriter comprising character printing mechanism including printing control keys operatively connected to type bars, key controlled power means, paper support mechanism, spacing means including an escapement arch operatively engageable by said type bars for stepwise moving said paper support mechanism in a forward direction to accomplish printing a line of characters, a ribbon providing a printing field and a print obliterating field, a ribbon vibrator, a feed arm operatively connected to said ribbon vibrator and actuated by the printing control keys to guide said ribbon to bring a ribbon field momentarily in impressing position, backspace drive means for stepwise moving said paper support mechanism in a backward direction in letter width increments, the improvement which comprises a manual key operatively connected to a special type bar carrying a universal obliterating type font, said type font being controlled by said manual key to impinge on said ribbon, said special type bar being free of any engagement with said escapement arch whereby actuation of said manual key will not effect movement of said paper support mechanism, link means operatively connecting said feed arm to said special type bar for moving said feed arm independently of any movement effected by the actuation of any of said printing control keys, said feed arm having a slot permitting movement of the feed arm beyond the movement effected by the actuation of any of said printing control keys, said special type bar when actuated by said manual key moving said feed arm and effecting elevation of said ribbon vibrator to position the print obliterating field in impressing position to be impinged upon by said type font to obliterate a character imprinted in error.