Patent GB-211954-A (GB)
Title: Improvements in typewriting machines
IPC: B41J19/76
Filed: 1922-11-29
Abstract: 211,954. Brougham, F. J., (Addograph Co.). Nov. 29, 1922. Relay type-lever actions; carriage-returning mechanism; letter-spacing mechanism; back-spacing mechanism; line-spacing mechanism; carriagereleasing arrangements. - Relates to typewriters with a reciprocable type-lever actuator and with mechanism which feeds the carriage with the rotatable platen as well as gives it a running movement in either direction and which comprises a pinion gearing with a rack on the carriage and rotatable by a continuously-driven shaft The letter-spacing mechanism is operated directly from the actuator, which is normally latched but releasable by the character keys, is moved forward by a spring to impel the type-lever corresponding to the operated key to the platen, and is retracted by temporary connection to the continuously-driven shaft. The type-lever actuator mechanism may be of the forms described in Specifications 25038/13 and 210,894. Line-spacing and case-shift mechanism operable from the continuously-driven shaft are also provided. A power shaft 31, Fig. 5, continuously driven by an electric motor, carries friction slip clutches actuating freely-mounted bevel gears 64, 65, Figs. 4 and 10. The clutches comprise fibre discs 66 co-operating with metallic friction cones 123 having four radial slits acting to keep the discs 66 clean. The gears 64, 65 permanently engage a bevel gear 63 on a vertical shaft 62 operating the platen carriage 119 through pinion 61 and rack 60. The carriage 119 is moved in one direction or the other by engagement of one of the friction clutches due to movement along the shaft 31 of one of the gears 64, 65, this movement being produced by resilient arms 67, 68 pivoted together and operated by keyactuated levers 72, 153, 69. One key 113 controls a lever 72 and also operates a paragraph stop, whilst a second key 73 controls the lever 72 only. The lever 72 also operates line-spacing mechanism, whilst levers 153, 69 are operated by keys giving carriage movement without line-spacing. A friction disc 38, Figs. 4 and 5, fixed to the power shaft 31, and which operates case-shift mechanism through a key-controlled friction cone as described in Specification 208,767, co-operates with a second friction cone 39 on a freely-mounted pinion 43 operating line-spacing mechanism. The cone 39 is controlled by a resilient lever 40 operated through an arm 41 by a line-spacing key or through a second arm 75 by the lever 72. A pivoted segment 44 with stop arms 45 engages the pinion 43 and operates a rock-shaft 48, an extension 49 of the shaft 48 engaging a pivoted frame 89 on the carriage 119. The frame 89 carries the line-spacing pawl 52, extreme movement of which is limited by a stop and which is normally disengaged from its ratchet-wheel 16 by a pivoted pawl-controller. This controller normally holds the pawl out of engagement with the ratchet 16 and is adjustable to give a feed of one or two teeth. The letterspacing mechanism is as described in Specification 211,966, a notched wheel 75<a>, Figs. 4 and 7, on the shaft 62 co-operating with pawls 76, 77 controlled by a cam plate 131 and operated by the universal type-lever actuator 20. The actuator 20 is driven forward by a spring 11 on release of a latch 26 by couplers connected to the keys, and is retracted by temporary connection to the shaft 31 after the type-lever has been operated through the coupler. The pawl 76 normally engages the wheel 75<a>, but for back-spacing, the pawl 77 is engaged instead of the pawl 76 by key-controlled movement of the cam plate 131. The letterspacing mechanism serves as a lock for the carriage 119 and is thrown out of action during linespacing and during running movement of the carriage in either direction by disengagement of the pawl 76 from the wheel 75 by a lever 9, Fig. 9, controlled by a vertical lever 80. The lever 80 engages stops 84, Fig. 6, on a slide 82, the slide 82 being operated by a cam surface 86 on a link 85 operated by the line-spacing rock-shaft 48. Motion of the slide 82 to release the carriage-lock is thus produced during line-spacing by the link 85, and during running movement of the carriage by engagement of the lower end of the lever 80 by cam surfaces on the levers 68, 153. By means of a finger-piece 88, Fig. 5, serving to raise the pawl 52 and to operate the mechanism 49, 48, 85, the carriage may also be released for manual movement. At the end of the carriage or other movements from the shaft 31. the friction clutches slip, excess pressure on the clutches being prevented by key-lever stops. Locking-devices.-Motion of the slide 82 to render the letter-spacing mechanism inoperative during line-spacing or running movement of the carriage also locks the printing mechanism in inoperative position, the end of the slide 82 engaging and preventing movement of the latch 26, Fig. 6, of the spring-driven type-lever actuator. Margin-stops; line-locking devices; tabulating- mechanism; tabulating-key actions.-Three stops 99, 106, 103, Fig. 12, adjustably mounted on the carriage 119, co-operate with a tappet 107, Figs. 12 and 14, on the machine frame. Each stop has flanges 147, 148, Fig. 17, engaging a rack bar 97 fixed to the carriage and is adjustable along the bar by a spring-urged pivoted bar 8 having a notch 141 engaging the rack 97 and a finger-piece 100 carrying a pointer co-operating with a scale on the carriage. The tappet 107 has an angular part 107a, Fig. 14, engaging the stops and is resiliently yieldable in either direction to absorb shock by means of a three-armed lever 93, the vertical arm 95 of which engages an aperture 143 in the tappet 107, and the other arms of which engage a leaf spring 92 and are of unequal length to equalize their resilient action. The part 107<a> is normally raised to engage the end stops 99, 103 and to pass the paragraph-stop 106, by engagement of a notch 108 on the tappet 107 with a pivoted lever 104 co-operating with stop 103 and operating the line-lock device. The part 107<a> is lowered by gravity or a spring to engage the stop 106 when the lever 104 is lowered under the action of a spring 114 and key-controlled linkage 111. The paragraph-key 113, Fig. 4, in addition to operating the tappet 107 to engage the paragraphstop 106, also operates through lever 72 the linespacing and carriage-returning mechanisms, the printing mechanism being locked and the carriagelock released. The platen-shift key may be operated simultaneously with the key 113. The carriage-return key 73 performs the same operations as the key 113 except the movement of the tappet to engage the stop 106. Two other keys give running movement to the carriage in either direction without line-spacing but with locking of the printing mechanism and unlocking of thecarriage-lock.