Patent GB-965777-A (GB)
Title: Improvements in keyboard-operated mechanisms
IPC: B41J3/50
Filed: 1961-06-15
Abstract: 965,777. Selective punching. INTERNATIONAL BUSINESS MACHINES CORPORATION. June 15, 1961 [June 22, 1960], No. 21596/61. Heading B4B. [Also in Divisions B6 and H4] A strip-perforating device is mounted on the side of a typewriter of the kind described in Specification 873,920 and perforates a strip with a code corresponding to each key depressed on the typewriter, the strip being subsequently used to control telegraphic equipment. Each code represents two characters i.e. an alphabetic character and a numerical or special character. A special code is automatically punched on the strip at the beginning of a sequence of letters or numbers (or before a single letter or number) to indicate which of the two the following character codes represent. The typewriter (shown in plan view in Fig. 2) comprises side plates 34, 35 and a plate 38, Figs. 3a, 3b, which carries the stripperforating device is mounted on the side plate 34 by means of rods 39, 40. Plates 41, 42 are mounted on the plate 38 at right angles thereto and carry comb-shaped guide members 44, 45 and a plate 46 having openings 48 in alignment with the spaces between the teeth of the members 44, 45. A group of thin metal strips 49 is arranged between the guide members 44, 45 and a second group of strips 50 is arranged between the member 45 and the plate 46, Fig. 5. A plurality of sensing pins 51 is mounted below the assembly of strips, each pin being urged upwards by a leaf spring 66 and having its upper end engaged in an opening 48. The pins are held in this position by a rod 58 which passes through slots in the pins and which is carried by arms 53, 54, 55 fixed on a shaft 56 journalled in the plates 41, 42 and carries a cam 61 which is engaged by a cam follower 60 carried by the arm 53. The typewriter includes a shaft 12 continuously driven by an electric motor 191, Fig. 3a, during use of the machine and a shaft 14 which is coupled to the shaft 12 by a singlerevolution clutch whenever a key is pressed on the keyboard. The shaft 14 drives the shaft 62 through bevel gears 192, 193, Fig. 3a, and rotation of the latter causes anticlockwise movement of the arms 53-55 so that the pins 51 may be urged upwards by their springs. Each strip 50 has a number of holes 68 which are normally out of alignment with the corresponding holes of the other strips 50. The strips 50 are biased to the right, Figs. 13a, 13b, by arms 70 which engage in holes 72 in the strips and are spring urged in a clockwise direction about pivot points on the machine frame. The arms 70 are normally latched in a vertical position and the latches are connected to the ends of bails 20-25 journalled in the typewriter side plates 34, 35 and projecting through the plate 38 into the strip perforating device. Whenever a typewriter key is pressed one or more of the bails 20-25 is rocked thereby releasing the corresponding arm(s) 70. The corresponding strip(s) 50 is (are) then moved to the right with the result that there is one vertically aligned set of holes 68 in the strips 50 through which one of the pins 51 can pass. Pressure on different keys causes vertical alignment of the holes 68 over different pins 51. Of the strips 49 the lower five 49a have, aligned with the pins 51, either holes 80 just large enough to receive a pin 51 or openings 81 long enough to allow movement of the strips in relation to a pin when the latter extends through them. Above the strips 49a are two strips 49b marked LTR and FIG. respectively, the FIG strip having a long slot 84 aligned with the pins 51 which sense figures and small holes 83 aligned with the pins 51 which sense letters and the LTR strip having a long slot 85 and small holes 86 in converse positions. The strips 49 are urged to the right by spring elements 88 but are normally maintained in a home position by a pin 92 extending through slots 93 in the slides and mounted on a lever 94, Figs. 3a, 13a. The lever 94 is controlled by a cam 98 on the shaft 62. When a character has been sensed by a pin 51 the cam 98 allows anticlockwise rotation of the lever 94 whereby those of the strips 49a in which openings 81 are engaged by the pin are moved to the right by their spring elements 88. Either the LTR or the FIG strip is also moved to the right at this moment if the operator has just commenced typing or if after pressing " letter " keys he presses a " figure " key or vice versa. The strips 49 have punch-controlling portions 146 at their right hand ends. A tape 107, Figs. 3b, 6, is punched by pins 115, 116 slidably mounted in a guide plate 112 carried by vertical plates 108, 109 parallel to the plate 38. The guide plate 112 is recessed at each end so as to receive reduced portions 118 of a pair of yokes 119. A plate 120 connects the upper ends of the yokes 119 and has openings through which the pins 115, 116 extend, the pins having collars 122 thereon which are held in abutment with the plate by springs 121. A die plate 124 and a stripper plate 125, each having holes to receive the pins 115, 116, are also carried between the yokes 119 and the tape 107 passes between the die plate and the stripper plate. The pins 115, 116 are normally held in the position shown in Fig. 6. Attached to the plates 108, 109 are two horizontal plates 135, 136 having holes 137, 138 respectively in alignment with the punch pins. The plate 135 is recessed to provide a space 140 into which the right-hand ends of the strips 49b extend. The right-hand ends of the strips 49a are received between the plate 135 and a guide 141 secured to the end of the guide member 44. The yokes are reciprocated vertically by cams 130 on a shaft 131 driven through bevel gears from the shaft 62. The rightward movements of the strips 49 described above take place as the yokes are moving downwards and when the pins 115, 116 are clear of the holes 137, 138 respectively. The portion 146 of the LTR strip 49b is wide enough to underlie all the holes 138 aligned with the pins 116 and that of the FIG strip is wide enough to underlie all but one of these holes. Each of the portions 146 of the strips 49a is wide enough to underlie one hole only of the holes 137 aligned with the pins 115. Thus when the strips 49 have moved to the right and the yokes start moving upwards one or more of the pins 115 and possibly all or all but one of the pins 116 are prevented from moving upwards into the holes in the plates 135, 136 and perforate the strip 107. After the punching operation the sensing pins 51 are lowered by the cam 61, the strips 49 are restored to their home position by the action of the cam 98 and the pin 92, and the strips 50 are similarly restored by the action of a cam 104 on the shaft 62 which actuates an arm 102 carrying a pin 101 which engages the strips 50. The holes punched by the pins 115 represent characters (letters or figures) and those punched by the pins 116 indicate a change from letters to figures or vice versa. There are six pins 115 of which one acts against a blank surface of the plate 135 and punches a series of feed holes 144 in the tape for engagement by a pin wheel 196 mounted on a shaft 198. The shaft 198 is driven through a pawl and ratchet device from the shaft 131 so as to advance the tape 107 step by step, the tape being automatically advanced two steps before actuation of the punch pins 116. The operation of the strips 49b is controlled by a latch member 150, Figs. 8, 9, carried by a vertical pin 151 pivotally mounted on a bracket 152 secured to a plate 153. The pin 151 has secured thereto an arm 154 carrying pins 155, 156 and an arm 158 which in combination with a spring 159 constitutes an over-centre biasing means. A spring- biased, pivoted arm 160 has a notch which engages a pin 161 on the arm 158 to maintain the latter in the central position shown in Fig. 8. Before use of the machine the latch member 150 lies along the centre-line of slots 162 in the strips 49b. The slots are formed with internal shoulders 165, 166 respectively and external shoulders 163, 164 are formed on the strips. If the operator first presses a " letter " key the LTR strip is moved to the right as described above and the shoulder 163 thereon engages the pin 155 on the arm 154, pivoting the latter in a clockwise direction, Fig. 9, so that the latch member 150 presses against the shoulder 165. When the LTR strip is moved back to the home position by the pin 92 the arm 154 is held by the over-centre biasing means in the position to which it has been moved and the member 150 engages behind the shoulder 165 so as to prevent the LTR strip from moving to the right if the next key pressed by the operator is a " letter " key. When the operator presses a " figure " key the FIG strip moves to the right, the shoulder 164 engages the pin 156 and swings the arm 154 in an anticlockwise direction. The member 150 now presses the shoulder 166 and when the FIG strip is returned to its home position will engage behind the shoulder to prevent the strip moving to the right again if the operator should next press a " figure " key. A T-shaped member 168 having arms 172, 173 and a slot 170 is slidably mounted over the pin 151 and a guide pin 171 and is biased to the right, Fig. 8, by a leaf spring 169. During operation the T-shaped member is held in the Fig. 8 position by a detent 180 engaging a shoulder 179 thereon but when a switch 183, Fig. 3a, controlling the motor 191 is moved to the " Off " position the detent 180 is rocked away from the shoulder 179 and the leaf spring 169 moves the T-shaped member to the right until the arms 172, 173 thereof engage the pins 155, 156 on the arm 154 and restore the latter to a position parallel with the plate 153 in which the latch member 150 again lies along the centre-line of the slots 162. When switch 183 is again moved to the " on " position and the first typewriter key is depressed after a period of disuse the T- shaped member is moved to its Fig. 8 position by mean