Patent GB-674943-A (GB)
Title: Improvements in power operated carriage return mechanism for typewriting and like machines
IPC: B41J11/24
Filed: 1949-01-31
Abstract: 674,943. Typewriters. ROYAL TYPEWRITER CO., Inc. Jan. 31, 1949 [April 16, 1948], No. 2663/49. Class 100 (iv). Carriage -retaining mechanism.-A machine having a continuously rotating power shaft 55, Fig. 3, has means for transmitting the drive to effect a carriage return movement and which comprises a normally disengaged clutch operated through a resilient face transmitting connection 88-92 operated by a key mechanism C, Fig. 1, which moves an actuator 117 and its pawl 125 into operative connection with another continuously rotating device 116; if the device 116 is not rotating the pawl 125 is moved to inoperative position with the return of the key. When the carriage return key 133 is operated, power from the continuous drive 116 is imparted to the actuator 117 in a manner described in Specification 674,941 and so pivots anticlockwise a lever 95 to which is attached a link 98. Link 98 is connected at its other end to an arm 101, Fig. 3, transmitting a oneway motion to the resilient force transmitting connection comprising a latch lever arm 88 freely mounted on shaft 85 and placed to be moved by a lip 101a of the arm 101. The latch 88 is formed with an ear 89 providing an anchorage for one end of a spring 90 the other end of which is secured to an ear 91 of a latch follower lever 92 secured to the shaft 85, so that movement of latch lever 88 yieldingly transmits motion to the shaft 85. Fixed upon shaft 85 is an arm 84 that operates a clutch-engaging lever 77 pushed at 79 and pressing by means of roller 81 against the right-hand pressure plate 72 of the clutch, Fig. 8. Through the centre of the shaft 55 is a transverse pin 71 engaging in slots 70 of a wearresistant friction clutch element 69 which normally rotates freely between the pressure plate 72 and the outer surface of a flanged drum 59 mounted on a hub 65 journalled on the shaft 55. The pressure plate 72 and the drum are rotatably locked together by struts 73 on plate 72 engaging in holes 74 in the drum 59 and urged apart by springs 75 so as normally to be spaced from the element 69. When the pressure plate is moved leftwardly by the clutch lever 77 the drum is rotated and winds up an internal spring 67 and returns the carriage. During typing, letter spacing is effected by the spring under control of escapement mechanism in the usual way. The clutch mechanism is held operative by a latch 102, Fig. 3, which is tripped at the completion of the carriage movement to automatically disengage the clutch by a carriage stop, Figs. 6, 7 (not shown), resiliently engaging a lever 36 connected so as to release the latch lever 88. The shaft 55 is driven preferably from the same source as the drive 116, through helical gears 46, 47 a short shaft 49 and flexible coupling 51, 52, 53. Line-spacing.-The initial movement of the tape 60 pivots a lever 25, Fig. 3, and through a roller and slot connection 23, 24 pivots bell crank levers 22, 17 operatively connected to the usual ratchet and pawl line-spacing mechanism. Margin and carriage stops.-The mechanism is similar to that described in Specification 534,975.