Patent GB-783979-A (GB)
Title: Improvements in or relating to printing mechanisms for typewriting machines and the like
IPC: G06C11/04
Filed: 1955-01-06
Abstract: 783,979. Type - printing telegraphy. OLIVETTI & CIE SOC. PER AZIONI, ING., C. Jan. 6, 1955 [Jan. 11, 1954; Dec. 29, 1954], No. 384/55. Class 40 (3). [Also in Group XVI] In a typewriter or like machine having a single printing position, one of four type carriers can be positioned for printing and each carrier is selectively set. Four type wheels 22, Fig. 1, each carrying ten types are mounted in a cage comprising two side plates 19 connected by cross members 36, 37 and rotatable about vertical pivots 38. Each type wheel is set by a rack 20 engaging a pinion 21 and the appropriate wheel is selected for printing by releasing the mounting cage for pivotal movement to a position controlled by a stop 6. The actuation is controlled by a cycle of a power shaft 46 mounting cams 47, 50. The forty keys 1 are each attached to a setting slide 2 and when depressed the slide acts through projections 7, 8 to depress one of each of a series of stops 5, 6. The slide 2 also depresses a universal bar 41 which through a lever 40 removes a roll 49 from a step 48 in the cam 47 allowing the shaft 46 to start its cycle and at the same time a vane 43 locks the one slide 2 depressed and the remaining slides elevated by engagement with their teeth 44. As the cycle proceeds, a universal bar 55 is moved rearwards allowing one of the four slides 9, connected respectively to the racks 20 which correspond to the selected stop 6, to move, until arrested by the engagement of a projection 12 with a set stop 5, thus positioning the corresponding type wheel 22. A similar slide 60, not shown, is also released and allows a spring to pivot the cage mounting the type wheel until one of the projections on the slide 60 engages the set stop 6 thus positioning the appropriate wheel 22 in the printing position. As the cycle proceeds a latch 32 will be withdrawn from the selected and positioned type wheel mounting lever 23 allowing it to be pivoted about a pin 24 to effect printing. The cam then restores the parts to their original position. In a modification, Figs. 4, 5, four type wheels 115 are mounted on slides 141 and are each set by a segment 139 and the wheels are moved to the printing position by scissor-like levers 155, 156, Fig. 5. A key 80 depresses a slide 81 which engages the end 88 of a beam 89 depressing it so that as the beam pivots about a bar 92 a spring 93 draws it under a comb 90. The end 88 of the beam also acts on a universal bar 96 to rock the lever 97 to unlatch a lug 100 of a lever 101 allowing a spring 189 to rock it, thus moving the motor bar 105 to start the main shaft 106 on one cycle. As the lever 101 pivots a universal bar 103 engages with the the projection 104 to move the beam 89 rearwards so that its end 122 engages one end 121 of one of the levers of one of the sets of levers 117 to 120 and also to unlock the projection 94 from the comb 90. A pin 107 also moves a lever 108 so that its tooth 111 is in the path of projection 112 of a corresponding disc 113 on a shaft 114. The selected lever 117 to 120 acts through a slide 132 to position a lug 158 between the lower ends 155<SP>1</SP>, 156<SP>1</SP>, Fig. 5, of the scissor levers 155, 156 so that when later in the cycle the power shaft 106 the ends 155<SP>1</SP>, 156<SP>1</SP> close on the positioned lug 158 the levers 155, 156 swing until they contact a lug 154 of the mounting of the slide 141 to move the appropriate type wheel 115 into the printing position. The appropriate type wheel 115 is set by a cam 170 acting through a bail 182 and an actuator 183 on a lever 138 attached to the segment 139 the wheel 115 which is arrested in the position determined by the engagement of a projection 112.of a corresponding disc 113 with the tooth 111 of the lever 108. Finally, a cam 153 acts to allow a spring 152 to cause the hammer 149 to strike the slide 141 of the set and positioned type wheel 115 to cause it to imprint on a platen 150. The cam then restores the parts to their original position but if a key 80 is struck before the completion of the machine cycle the bar 103 is still in the dotted position as shown in Fig. 4 so that the beam 89 pivots about the projection 104 and the projection 94 becomes latched in the operative position under the comb 90. Thus, the lever 97 is depressed and at the end of the machine cycle as the bar 103 is restored, releasing the beam 89, the lug 100 is not arrested by the lever 97 and a new machine cycle is immediately started the bar 103 again moving the beam 89 rearwards. When embodied in telegraphic apparatus the usual combination bars actuate the slides 2 or 82.