Patent GB-828535-A (GB)
Title: Improvements in typewriters
IPC: B41J2/27
Filed: 1956-06-18
Abstract: 828,535. Typewriters. INTERNATIONAL BUSINESS MACHINES CORPORATION. June 18, 1956 [June 20, 1955], No. 18764/56. Class 100(4) The wires of a printing typewriter are set by a code rod or rods having a predetermined arrangement of depressions, and movable both longitudinally and about its axis to bring the depressions into alignment with the non-printing ends of the wires, the means for positioning the code rods being driven by a continuously rotating power roll which also supplies power for setting the wires and moving the printing head. Depressing a key releases rotatable cam 32, Fig. 1, through key lever 26 and trip lever 30, to engage it with power drive roll 24. As cam 33 revolves, lever 34 rocks clockwise about shaft 35 and lifts notched slide member 37. Certain of bails 38-43 are rocked, coding being effected by cut out portions on the bails. Up to six horizontally movable rods such as 47 are moved by the rocking of a corresponding number of bails through a system of levers and bell-cracks, such as 53, 57. Rods such as 47 rotate in 90 degree steps up to 270 degrees, and move the code rod 61 axially in steps of 1, 2, 4 and 8 times the minimum displacement. These rods control axial movement through linkages such as 62, 67, which move wedges 64, 66, 69, 70, to raise the top of the wedge and roller stack, this displacement being transferred to code rod 61 by rods 73, 75, 77, 79. If more than one code rod is used all are simultaneously positioned. Fig. 5 shows the wedge and roller stack, and rack and pinion 86, 87, by which the code rod is rotated. Wire setting is accomplished by appropriate wires being pushed upwards by the code rod, wires opposite holes not being displaced. The code rod is raised by wedges 121, Fig. 4. which are moved to the right by power from roll 24 transmitted through rod 117 and cam 116 released by trip lever 115. Lever 115 is moved by lever 111 in turn depressed by extension 108 of lever 34. The latter being actuated by a character key, the time delay required for setting the code rod is governed by the space between extension 108 and bail 110. As lever 117 moves to cause the wires to be set, arm 128, Fig. 4, lifts trip lever 129 allowing a cam to engage roll 24. This cam rocks a lever anti-clockwise, lifting rod 134, Fig. 1, and causing printing head 124 to move towards platten 22. The printing wires are reset by a solenoid energized when a pair of contacts are closed by the printing head arm, which mechanically moves a slide down, bringing the wires 101 with it. All other parts are returned to their initial positions by suitable springs, not shown. In an electro-mechanical modification, lever 34, Fig. 10, is moved as previously described to lift slide member 138 having insulated buttons 139 which allows certain of spring contacts 140 to touch contacts 141 in accordance with the code in use. Thus, up to six circuits are made. Once a circuit is completed a relay is held closed by contacts which complete a holding circuit. By making the above circuits, up to six solenoids such as 150-153, Fig. 10, are energized. Each is connected mechanically as by link 156, to lever 157 to release cam 158 mounted on lever 159. Lever 159 moves. one of the horizontally movable rods such as 47 which set the code rod as described above. Wire setting is effected as before, the necessary delay to allow for code rod positioning being governed by the space between 108 and bail 110, as in Fig. 4. A contact is also opened by bail 110, which opens the circuit to relays which were previously closed, bringing the circuit back to its original condition. Solenoids such as 150-153 are also de-energized allowing the mechanical parts to return to their original positions. Wires are reset as before. Case shift. Depressing shift key 88 moves wedge 100 to the right, Fig. 5, through linkages 98, 97 and 95, power being taken from roll 24 by cam 94 released by trip lever 93, this rotates the code rod through 45 degrees so that either upper or lower case characters may be selected. In the electromechanical modification a solenoid replaces some of the mechanical linkages between the key and cam 94. Coupling machines. Several machines may be controlled by one keyboard, or tape or punched card control may be employed. Specification 638,935 is referred to.