Patent GB-797516-A (GB)
Title: Improvements in or relating to printing telegraph apparatus
Inventor: SALMON REGINALD DENNIS
IPC: H04L17/08
Filed: 1954-09-23
Abstract: 797,516. Selective perforating apparatus. CREED & CO., Ltd. Sept. 16, 1955 [Sept. 23, 1954], No. 27514/54. Class 31 (2). [Also in Group XVI] A printing and perforating apparatus in which key-bars directly operate type-levers to print a character and also control mechanism for perforating a tape, comprises a code vane for each element of the combination to be perforated and means operative on actuation of a key for moving all the code vanes positively in respective directions. When a key 1 of the typewriter is depressed, a type lever 29 effects impression at the platen and at the same time the key lever 2 engages a lever 3 pivoted about an adjustable fulcrum 4 to raise a combination bar 6; these combination bars have various notches which selectively operate one or more of the code vanes 7.-11. At the same time the type lever is making its impression it engages a member 30, operates the escapement mechanism and through mechanism 31- 36 operates the bar 38 which is held in its raised position by a locking latch 41, Fig. 3. The locking latch is urged clockwise by a lever 48 whose other arm 42 closes electrical contacts 43 so that the armature of the perforating electromagnet is energized. An arm 49 of the locking latch 41, Fig. 2, engages a frame 51 which locks all code members 18 which are thus fixed either in operative or inoperative positions as determined by the code vanes 7-11. Operation of the armature 75 of the electromagnet draws a link 78 to the right and pivots a frame 27 anticlockwise, a cam slot 26 in this frame pivots a common frame 24 away from five selector levers such as 21 which are thus allowed to move clockwise according to the setting of the code bars 18 so that a draw-bar 66 and mechanism 67, 68 and 69 moves a strike projection 70 out of the path of the electromagnet hammer so that only the selected punches 72 are operated. Referring to Fig. 3, the frame 27 has a second cam slot 56 which operates a lever 102 and, via a push-rod 57, strikes a block 58 and through a lever 61 and linkage 63, 65, a lever 54 engages the locking latch 41 to release it and open the electrical contacts 43 and the arm 49 releases the code bar locking frame 51. A timing latch 44 prevents contacts 43 closing again until armature 75 has completely returned, also a latch 83 prevents further operation of the electromagnet if the key lever has not been released by the time the latch 41 releases the arm 48. A run-out key external to the typewriter is provided to run a quantity of blank tape out of the perforator, this mechanism holds the latch 83 in rest position (Fig. 4, not shown). Perforation of letter and figure shift codes. When figure signals are being received a bail 13 (Fig. 5, not shown), is raised, and when a letter signal is received a bail 12 is raised, to lift a latch 88 and move an insertion bar 90 immediately to the right of notches 94 on all reading bars 20 so that none can be moved by the selector levers 21. This means that perforations will be made in all five positions and an " all marked " letter-shift signal is perforated. When a figure signal is next received, an insertion bar 91 is raised and reading bars 1, 2, 4 and 5 are engaged to the right of projection 95 but reading bar 3 is struck by a projection 96 and is lifted. When the electromagnet is energized, selector levers 21 tend to move to the right and marks are punched in these four positions. Number 3 bar is not restrained even if the code bar is in the raised position and no perforation is made in this position. When either of the insertion bars is operated, the electromagnet is arranged to perform two cycles by means of a mechanism 97, 99 cam track 100, and pushbar 57, which now engages a block 103 on a crank 105. Movement of the crank 105 frees bell-crank 109 whose arm 111, via projection 137, tries to draw member 97 and insertion bars 90 and 91 downwards, but friction of these bars with the reading bar 20 prevents this happening until selector levers 21 cease their effort on the bars 20 which happens at the end of the return of the electromagnet 75. When the bar 99 is drawn down bell-crank 109 moves a lever 113 leftwardly and member 112 clears an arm 114 of the contact lever 42 so that the contact closes again. The bars 90, 91 are thus lowered out of the path of the reading bar 20 before the contacts are allowed to close a second time. The electromagnet is then energized a second time for the one letter or figure key operation and the corresponding codes are perforated. A locking bar is provided which engages the key bars and prevents them being operated again until the code combinations have been punched every time that a shift is made on the typewriter. Specification 777,243 is referred to.