Patent GB-303060-A (GB)
Title: Improvements in actions for typewriting machines
IPC: B41J1/08
Filed: 1928-12-11
Abstract: 303,060. Royal Typewriter Co., Inc., (Assignees of Michelsen, W. 0.). Dec. 27, 1927, [Convention date]. Relay type-bar actions; case-shift mechanism. - In a power-operated sliding type-bar machine, each typebar is provided with a number of groups of types and is associated with a group of key-levers equal in number to the types in a group, and a movable support for the type-bar co-operates with mechanism which is normally in position for actuation by the power devices. In the action shown in Fig. 1, the type-bar 1, provided with two pairs a, band c, d of types, is mounted on a rocking support 2 and is controlled by either of a pair of key-levers B, C. The support is formed with guide-lugs 4, 6 engaging the faces and edges of the type-bar. In some cases the lugs engage one face only and pins are provided for engaging the other face. The typebar is connected by a link 9 to a rocking arm 12 which is connected by a link 22 to a bell-crank 24, the bell-crank and rocking arm being mounted on a bracket 14 adjustable by means of a screw 17. The bracket has a resilient stop 35 for engaging an ear 34 on the bell-crank. The bellcrank carries a link 75 which is connected by a link 77 to the key-lever B and abuts on a pin 74 carried by an arm 69 which can rock on the pivot 3 of the support 2 and is connected by a spring 71 to the support. A lug 72 on the support normally rests on the nose 73 of the arm 69. The bell-crank is connected by a link 28 to a loose arm 30 on a constantly rotating shaft 37 provided with a ratchet-wheel 38 which cooperates with a pawl 59 pivoted at 58 to the arm. An arm 61 pivoted on the pivot 58 abuts on a lug 68 on the cam 30 and has a pin 63 abutting on a stop 65. A spring 64 connected to the pin 63 and a pin 62 on the pawl normally holds the pawl out of engagement with the ratchet-wheel and in contact with a pad 57 on a bell-crank 44. The end of the pad 57 normally engages a pad 66 on the arm 30. The key-levers B, C are connected to hooked links 52, 53 engaging slots 50, 51 in the bell-crank 44. When the key-lever R is depressed, the support 2 remains at rest and impression is effected from the type b or a as determined by the position of the platen A. Depression of the key-lever B withdraws the link 75 from the pin 74 and causes the bell-crank 44 to depress the pawl, and the spring 64 holds it in engagement with the ratchet-wheel, the arm 30 being thereupon rocked and causing the type-bar to move for impression. At the end of the movement, the pawl engages a stop 42<1>, the pin 63 rides on a cam 43, and the pawl is released from the ratchet-wheel. A spring 32 in connection with the link 28 then returns the link and the associated members to the normal position. On release of the key-lever, the key-lever and bell-crank 44 are returned by springs 54, 47, and if release is delayed the pawl abuts temporarily on the end of the pad 57. The cam 43 and stop 42<1> are formed on rocking plate 39 which engages a pin 40 on a revoluble adjusting-member 41. When the key-lever C is depressed, the action operates in the above-described manner and the link 75 is, by means of the spring 71, effective to rock the support 2, impression being effected from the type d or c as determined by the position of the platen. If the type-bars have more than two groups of types, the arm 69 is provided with more than one pin 74, and additional key-levers associated with each type-bar cause the link 75 to co-operate with the corresponding pin. The support is connected to a returning-spring 78. The movements of the support are limited by a silent stop-device consisting of a disc 84 pivoted eccentrically on an arm 82 on the support and co-operating with stop-screws 80, 81. In an alternative stopdevice, the arm 82, Fig. 3, moves balls 88 along inclines 87, the movement being limited by stopscrews 89, 90. The inclines are formed on a member 85 which is provided with a slotted base 86 Specification 298,984 and 299,305 are referred to.