Patent GB-554819-A (GB)
Title: Improvements in continuous sheet-feeding mechanism for typewriting machines
IPC: B41J11/36
Filed: 1941-12-11
Abstract: 554,819. Typewriters. ROYAL TYPEWRITER CO., Inc. Dec. 11, 1941, No. 13522/42. Convention date, Feb. 5. Divided out of 554,795. [Class 100 (iv)] Platen-rotation for blanking.-In sheetfeeding means in constant driving- connection with a gear operated in one direction by a reciprocable rack which is automatically moved out of and into engagement with the gear at the end of the operative and return strokes, a handle for operating the rack carries adjustable means for determining the operative stroke. In the mechanism shown, a rack 25 is mounted on a support 29 which is pivoted at the rear on a pin 30 on a plate 10 secured to the carriage end-plate 4. For guiding the rack, the support is provided at the rear with rollers 38 and a plate 33, and at the front with lugs 39, 40 and a plate 43. The rack is urged forwards by a cord 49 wound on a spring drum 47, the movement being limited by co-operation of a bracket 53 on the rack with the lug 39. Normally, the support 29 is in depressed position, and the rack engages a pinion 55 on the platen-shaft 6. The support is held down by means of a pivoted arm 58 having a slot 57 engaging a pin 56 on the support. The arm 58 is connected by a spring 60 to a pivoted arm 63 which engages the pin 56 and is connected by a spring 65 to a latch 67 co-operating with a pin 69 on the support. The rack is provided with a U-member 70 carrying, on a pivot 71, a stop-member 27 which co-operates with the lug 39 and is provided with a pin 74 for co-operating with the arm 58. When the front edge of the form-web has been inserted in the nip of the platen 7 and the rear feed-roller 20, the stop-member is raised by means of a finger-piece 28 on the handle, and the rack is pushed rearwards until the rear end of the member 70 engages the front end of the support 29. The platen is thereby rotated through, for instance, twenty-three line-spaces and the first form is so positioned that the first typing-line thereon is brought into the printing line. A pin 75 on the member 70 rocks the arm 58, and an enlargement 57a of the slot 57 permits the pin 56 and consequently the support and rack to be raised by the spring-urged arm 63. The latch 67 then co-operates with the pin 69 to hold the support and rack in raised position. The platen is temporarily locked by a dog 77 which is moved into engagement with the pinion 55 by the member 70. On release of pressure on the fingerpiece 28, the rack is returned by the cord 49, and remains out of engagement with the pinion 55 until the bracket 53 approaches the lug 39. Thereupon, the bracket releases the latch 67, the arm 58 is rocked, an incline 57b co-operates with the pin 39 to depress the support 29, the rack re-engages the pinion, and the pin re-enters the slot 57. The finger-piece 28 is then released, and a spring 72 returns the stopmember 27 to normal position. One or more lines are then typed on the first form, the rack being stepped rearwards by the pinion, and the rack is again pushed rearwards but without raising the stop member until the rear end of the stop-member 27 engages the front end of the support 29. Thereby the platen is rotated through twenty line-spaces, and the first typing-line on the second form is brought into the printing line, one, two or more line spaces having been effected by the line-spacing mechanism, and the remainder by the rack.