Patent GB-1154111-A (GB)
Title: Encoder.
IPC: B41J7/66
Filed: 1967-01-03
Abstract: 1,154,111. Typewriters &c. INTERNATIONAL BUSINESS MACHINES CORP. 3 Jan., 1967 [14 Jan., 1966], No. 192/67. Heading B6F. Machines with types on spherical surfaces; power assisted type actions; permutation typeselecting mechanisms.-A typewriter having a spherical type head 72 mounted on a traversible carriage (not shown) is provided with a character selection mechanism comprising a stack of slides 60, and a plurality of probe members 50 one for each character key lever 20 the probe members being provided with a pair of opposed edges 51, 52 to probe coded slots 61, 62 disposed along opposite edges of the slides and associated with upper or lower case characters, respectively. Depression of a key lever 20 causes a primary dobber 26 to rock downwardly a control link 40 whose lug 47 depresses its associated probe member 50 whereby the latter is biased by a leaf spring 15 to move in one or otherdirection along line L to probe the respective coded slots 61, 62. Probe member is latched in its position by a lug 54, 58 which enters an aperture 35 in a bracket 34. Depression of probe member 50 enables a one-revolution clutch 13 through link 18 and latch 14, whereby a cam controlled slide mechanism 64 releases the slides 60 for movement under bias of springs 63 to rock character selecting latches 11. Slides 60 are then restored by the mechanism 64 and the probe member 50 is restored by the link 40 which is moved forwardly by a leaf spring 43 attached to a bail 42 which is reciprocated by a cam 44 and then upwardly by a leaf spring 46, whereby the arm 59 of probe member 50 is raised when a lever 45 has moved the probe member to release its lug 54 or the link 40, during its forward movement has engaged the arm 59 to release its lug 58 from engagement with the aperture 35. Closing electric circuits for printing.-The slides 60 may be provided with spurs to close electrical contacts 69 during their sliding movement. Case-shift mechanism ; key sections.-Coded slots 61, 62 are associated with upper and lower case, respectively, and the probe members 50 are biased to probe the slots by leaf springs 15 which are displaced by link 16 under control of a cam 17 which is actuated by a case shift mechanism 12 on depression of a case-shift key 22. Key levers; repeat power action prevention; repeated power action.-The key levers 20 are provided with slots 23 at one end to mount them pivotally on a bracket 31 and with hooks 25 at the other end for engagement with a rod 33 to limit their upward movement. Repeat power action due to protracted key depression is prevented by limiting the downward movement of the key lever 20 by causing a lug 28 to abut a stationary frame 38 and providing the primary dobber 26 with a surface 27 which arrests the restoring movement of the link 40. Repeated power action by certain keys is possible by replacing the lug 28 by a spring 28<SP>1</SP> so that the key lever may be depressed to a greater extent and by providing the key lever 20 with a secondary dobber 29 which engages the upper edge 48 of restored link 40 and keeps it in a depressed position in which the probe member 50 is probing repeatedly its associated coded slot 61, 62. Key touch regulating arrangements.-Key touch is regulated by varying the width of key lever restoring leaf springs 80 which engage lugs 81 on the key levers 20, whereby entire keyboard control is effected by an operator touch control lever 82 articulated to a crank arm 83. Key switches.-Mis-operation of fast sequentially operated links 40 is prevented by a ball interlock mechanism 41 which permits only one link to be inserted at any one time. Release of the links 40 is effected early in the cycle by a bail 42 actuated by a cam 44 as so to permit the insertion of a second link thereinto. The bail 42 carries a number of leaf springs 43, one for each link, which engage the respective link and move it out of the ball interlock a restoring spring 46 urging the link 40 upwardly into its starting position. Variable impression arrangements.-Stack of slides 60 is associated with a further slide 76 coupled to a cable 75 which is attached to a slidable yoke to displace a roller 74, mounted in a cradle 71, into contact with one of a number of cams 73 which effect angular displacement of the cradle articulated to the spherical type head 72.