Patent GB-234763-A (GB)
Title: Improvements relating to paper-carriages for typewriting machines
IPC: B41J19/18
Filed: 1924-05-20
Abstract: 234,763. Fischer, O., and Naamlooze Vennootschap Machina Maatschappij voor Handel en Industrie. May 20, 1924. Letter - - spacing mechanism. - Escapement mechanism comprises a rocking frame mounted on the framework and provided with fast and sliding racks co-operating with a dog connected to the carriage. A rocking frame 8, Figs. 1 and 2, mounted on the framework 7 is provided with a fast 9 and a sliding rack 10 having headed screws 11 passing through slots in the rack 9. A slide 17, mounted on a bar 18 on the framework, carries a pivoted dog 15 having a pin 14 engaging a notch in a plate 13 secured to the carriage 1. Springs 12 for cushioning the rack 10 engage the heads of the screws 11. At each operation, the frame 8 is rocked, for instance by an electromagnet 24, and the racks 9, 10 are moved out of and into engagement with the dog. The rack 10 is then moved to the right by a spring and, when the frame rises, re-engages the dog and permits the carriage to move one letter-space. The dog is rocked out of engagement with the rack 9 when the carriage is pushed to the right, and re-engages the rack when the hand is removed from the carriage, disengagement and re-engagement of the dog being ensured by means of a bar 19 adapted to retard the slide momentarily, the bar being mounted with slight longitudinal freedom on the carriage and being forked to engage a pin on the slide. Carriage-releasing arrangements.-The bar 18, Figs. 1 and 2, carrying the escapement-dog slide 17, described above, can be rocked to disengage the dog from the rack 10 for carriage-release. Paper carriages and supports.-(1) For detachably securing the platen frame 27, Fig. 2, to the carriage 1, 2, the cross plates 3, 4, Fig. 1, of the carriage are provided with pivoted spring-catches 30 co-operating with studs 28 on the platen frame. In mounting the platen frame, the studs are inserted in slots 29 in the cross plates, the catches thereby being pressed outwards and then returning to engage necks in the pins. On pressing finger-pieces 32, the catches are released, and the platen frame is raised by means of springs 31 engaging the pins. (2) For detachably mounting the platen roller 25, Fig. 3, in the platen frame, the platen roller is provided with a head 33 loosely mounted on a spindle 35, and a head 34 having studs 36 engaging a flange on a spindle 37 which is mounted in a sleeve 38 and is pressed inwards by a spring 39. On retracting a knob 40 on the spindle 37, the flange is released and the platen can then be withdrawn from the spindle 35, and removed from the machine. Platen-roller couplings.-The line-spacing wheel is formed on a clutch disc 42, Fig. 3, normally retained by a spring 44 in engagement with a clutch disc 41 which is coupled by a pin 43 to the head 33 of the platen roller. The clutch discs are loosely mounted on a spindle 35 secured to the platen frame and provided with an internal screw 45 having a cross pin 46 which passes through a slot in the spindle and engages the clutch disc 42. A nut 47 engaging the screw gears with a pinion 48 provided with a handle 49 which is turned to uncouple or couple the clutch disc 42.