Patent GB-822917-A (GB)
Title: Improvements in printing mechanisms
Filed: 1956-05-02
Abstract: 822,917. Selective printing. INTERNATIONAL BUSINESS MACHINES CORPORATION. May 2, 1956 [May 4, 1955], No. 13513/56. Class 100(4) In a printing mechanism of the type controlled.by punched records having digit and/or group control holes similar to that described in Specification 605,132 a single delay clutch is provided between the print magnets and the type group printing clutch. As described in the prior Specification the type wheels 45 are rotated by a group selecting clutch 30 to bring the appropriate group of types to the printing position and a printing clutch 90-93 causes an impression of one of the types in the group as determined by the group holes O, X, R or a N impulse. Print magnets 10 are energized by any hole which is sensed and disengage latch 13, 14 of a related link 16 allowing its spring 15 to move it to the left under the control of a rotating cam 17. When a digit hole is sensed a follower 19 enters a notch 17a of the cam 17 allowing movement of the link 16 and thus of a three-armed lever 59 to 61 which disengages its hook 57 from a pawl 55 of the delay clutch allowing engagement of a cam disc 52 with a shaft 50. Cam disc 52 once engaged rotates clockwise until a low 76 reaches a follower roller 71 which allows a spring 77 to rotate an arm 72 slightly clockwise so that a projection 80 contacts a triple arm lever 82 to hold the arm 72 against further movement as lows 105, 109 of the disc 52 are reached and until a cam edge 70 of disc 52 engages the roller 71 rocking the arm 72 counterclockwise so that its foot 83 engages a cam edge 84 of a release arm 40 of the type selecting clutch. Type wheels 45 are now rotated until an impression occurs. Magnets 10 have been immediately de-energized and the came edge 17b of the notch 17a has restored the link 16 which becomes a re-latched while cam disc 52 rotates until the hook 57 is re-engaged by the pawl 55. , A hole O, X, R sensed or a N impulse energizes the print magnet 10 a second time the link 16 moving to the left as the cam follower 19 enters notches O, X, R or N 1 , in the cam 17. Movement of the link 16 causes a finger 85 to rock an arm 87 so that its notch 126 registers with an extension 127 of the printing clutch release arm 88 which is rocked by a spring 89 to unlatch a pawl 90 when the second impulse is received as a low 120c of a cam 120 allows it to move -thus causing printing of the desired type of the selected group. Cam 100 however prevents movement of the triple arm lever 59-61 to start the delay clutch except when its low 100b is opposite the arm 61 which only occurs when digit corresponding to the combination of holes 8-3 or 8-4 are to be selected the hole 8 sensed first starts the delay clutch in the usual way and when the second hole 3 or 4 is sensed the slide 16 again moves to the left rocking the triple arm lever 59-61 so that. its arm 60 rocks stop member 82 out of the path of the projection 80 of the follower arm 72 which is thus allowed to rock clockwise into notch 105 or 109 of cam disc 52 so that its extension 83 engaging a cam edge 107 of the arm 40 releases the selecting clutch before the cam edge 70 acts on the roller 71. Projection 110 on slide 16 co-operating with extension 111 of the arm 72 while the slide 16 is in its leftwards position prevents movement of the arm 72 clockwise until the slide 16 is restored and acts as a lock to prevent improper printing of the 8-4 group characters when a 8-3 group combination is present. Selection of one group of type is effected by a N impulse which by print magnets 10 causes the follower 19 of the slide 16 to enter notch N1 of the cam 17, movement of the triple arm 51 being prevented by cam 100. As cam 17 rotates further notch N2 allows sufficient further movement of the slide 16 leftwards to cause direct engagement of the type group selecting clutch by the action of the slide foot 110 on the extension 111 of the arm 72. Selection of a type in this group occurs in the normal way.