Electrical apparatus

Claim 1

A MECHANISM FOR ADVANCING A RIBBON UNDER TENSION PAST A PRINT STATION, COMPRISING A PAIR OF SPOOLS SPACED FROM EACH OTHER, A DRIVE ROLL POSITIONED BETWEEN SAID PRINT STATION AND SAID SPOOLS, THE PATH OF SAID RIBBON CONSISTING OF A PAIR OF SECTIONS WHICH EXTEND FROM RESPECTIVE ONES OF SAID SPOOLS TO SAID PRINT STATION AROUND SAID INTERMEDIATELY POSITIONED DRIVE ROLL, SAID PATH SECTIONS CONVERGING ON OPPOSITE SIDES OF SAID DRIVE ROLL, A PAIR OF SPACED PINCH ROLLS, MEANS RESPONSIVE TO THE TENSION OF SAID RIBBON FOR URGING SAID PINCH ROLLS TOWARD SAID DRIVE ROLL TO GRIP SAID RIBBON THEREBETWEEN, MEANS FOR SIMULTANEOUSLY ROTATING SAID SPOOLS SO AS TO PULL SAID RIBBON IN OPPOSITE DIRECTIONS WITH SUBSTANTIALLY EQUAL FORCES, MEANS FOR INDEPENDENTLY ROTATING SAID DRIVE ROLL IN A SELECTED DIRECTION AT A SINGLE PERIPHERAL SPEED LESS THAN THAT OF SAID SPOOLS, SAID DRIVE ROLL ROTATION MEANS BEING ADAPTED TO OVERRIDE SAID SPOOL ROTATION MEANS TO ADVANCE SAID RIBBON IN SAID SELECTED DIRECTION ALONG ITS PATH AT SAID DRIVE ROLL SPEED.