Patent GB-601603-A (GB)
Title: Improvements in printing machines
IPC: B41J19/74
Filed: 1945-03-19
Abstract: 601,603. Typewriters &c. STEVENS, A. H. (Smith & Corona Typewriters, Inc., L.C.). March 19, 1945, No. 6875. [Class 100(iv)] Carriage-returning mechanism; typelever actions: - In printing-machines of the kind wherein printing is effected at a fixed line and provision is made for relative longitudinal and line - spacing movements, e.g. typewriters and recording calculating machines of the travelling platen - carriage type, mechanism for returning a paper-carrying carriage comprises a power-driven rotary shaft, a carriagedriving clutch biassed to engage and engagement of which connects the drive shaft and carriage for return movement thereof, mechanism for disengaging the clutch on arrest of the carriage, a latch which is biassed to latch the clutch against engagement upon disengagement thereof, and retracting-mechanism for the latch, which is adapted to be connected to the drive shaft to retract the latch and so free the clutch. As shown applied to a typewriter comprising a platen roller 12, Fig. 2, rotated for line spacing by a ratchet 18 and pawl 19, a rod 104 connected to an arm 21 carrying the pawl being actuated from a rotary shaft 36 driven by a high speed motor 39 through reduction gears, through a one-revolution clutch controlled from a key 41, return of the carriage to commence a new line is effected at the same time from the same shaft through a clutch which is thrown in by mechanism actuated from the one-revolution clutch and is disengaged when the carriage engages a margin or other stop. On depressing the key 41, a bar 62 fixed thereto swings about a pivot 63 and, through a link 75 and levers 73, 74, pushes a tappet bar 76 forward whereby a shoulder 79, Fig. 4, on the bar 76 engages a lug 80 on one arm of a detent 51 normally preventing movement of a pawl 43 into engagement with a ratchet 42 fixed on the shaft 36. The pawl 43 is carried by a disc 45 fixed to a mutilated pinion 47 which rocks a gear segment 90 pivoted at 89 and then releases it. The end of the member 90 is forked to receive a pin 87 on an arm 86 pivotal about the shaft 36, and a pin 97 on the arm 86 engages an arm of a lever 93 which rocks counterclockwise so as to move downwardly an arm 95, a lug 100. on the lower end of which hits the bar 76 so as to release the detent 51 which returns to normal position where it intercepts the pawl 43 after one revolution: a catch 57 adjacent the pawl engages behind the pawl-carrier to lock it in position. The lever 86 actuates the rod 104 through a bar 108, Fig 2, which is adjustable for length and carries a roller 109 engaging under a plate 107 fixed to a shaft 101 carrying an arm 103 connected to the rod 104. Downward movement of the arm 95 causes a lever 143, Fig. 7, to rock about a pivot 144 whereby a disc 140 is moved along the shaft 36 thus releasing a pawl 126 which then engages a ratchet fixed to the shaft 36. The pawl 126 is pivoted to a carrier 123 which rotates and through springs 134 turns a disc 129 fixed to a bevel gear in mesh with a bevel 119, Fig. 2, which is fixed to a telescopic universally jointed shaft 118 and rotates a pinion 117 engaging a rack 116 on the carriage. When the carriage engages a stop, the disc 129 is arrested, and the carrier 123 continues its rotation to an extent limited by a pin-and-slot connection, when the tail of the pawl 126 engages a pin 136, whereupon the pawl is disengaged from the ratchet and the carrier 123 is arrested. The disc 140, which has been held away from the carrier by a pin 138 on the pawl, is then returned by springs to normal position where the pin 138 rests on its periphery, and allows the return of the arm 95 and therefore the tappet bar 76, key 41 and associated parts to normal position. Any subsequent depression of the key 41 while the carriage is against the stop effects further line spacing.