Patent GB-1112342-A (GB)
Title: Improvements in or relating to typewriters for producing code signals
IPC: H04L13/16
Filed: 1965-05-25
Abstract: 1,112,342. Typewriters; selective printers. NIPPON ELECTRIC CO. Ltd. 25 May, 1965 [25 May, 1964], No. 22004/65. Heading B6F. Keyboards; power input arrangements; combination type-selecting mechanisms.-A typewriter used as an input-output device in a computer is provided with a keyboard, Fig. 1, the keys of which are each associated with three letters whereby the upper case corresponds to the standard alpha-numerical lay-out, the lower case corresponds to the Russian alphabet and some special characters and the middle case corresponds to special characters only. Each upper case character is identified by an upper case code combination and a main code combination, Figs. 2A, 2B, each lower case character is identified by a lower case code combination and an auxiliary code combination. In the middle case some of the middle case characters are identified by an upper case-code combination and a main code combination and some by a lower case code combination and an auxiliary code combination. The respective code combinations correspond to the depression of a character key and a case-shift key. Depression of a key 4, pivots a key lever 2 about a pivot shaft 28, Fig. 3, and a code plate rocker 14 mounted pivotally on a code switching plate 12 slidable in a slot 10 of the key lever engages with its lug 24 one or the other of projections 26, 27 associated with code plates 6, 8 to rock the code plates about a shaft 30. The code plate 6 is associated with the upper and lower case characters, whereas the code plate 8 is associated with the middle case characters only. The code plate 6 has an opening 62 from whose upper bank extend the upper case code protrusions 64-1 . . . 64-7 and from whose lower bank project lowercase code protrusions 66-1 . . . 66-7, co-operating with code bail groups 74-1 . . . 74-7 and 76-1 . . . 76-7, respectively. The code plate 8 is associated with middle case characters only and has an opening 62<SP>1</SP> from whose upper bank depend protrusions 64<SP>1</SP>-1 . . . 64<SP>1</SP>-7 which co-operate with the bails 74-1 . . . 74-7. The code plate 8 has only one set of protrusions either 64<SP>1</SP> or 66<SP>1</SP> depending on whether the character is associated with the main or auxiliary code group. Associated with each code plate is a depending lug 38 which on rocking of the code plate pivots a clutch bail 42, which in turn pivots a clutch lever 44 to release it from a retaining plate, whereby a clutch link 48 is pulled by a spring 50 to operate a onerevolution clutch which rotates a cam-shaft 54, whose cam ridge 56 engages a shoulder 58 on the code plates 6, 8 to rock the code bails 74 or 76. The code bails in turn displace respective main or auxiliary code activating plates 84-1 . . . 84-7 or 86-1 . . . 86-7 co-operating with case-shift levers 90-1 . . . 90-7 which through the intermediary of links 102, 104 close contact switches 106 whose combination corresponds to the respective case of the characters. The main or auxiliary code combination is selected by depression of the relevant case-shift key, which closes one of contacts 210 or 214. The code plates are restored by springs 36 or 37. Repeat power action prevention.- Repeat power action with the key lever 2 held in a depressed state is prevented by slidable movement of the plate 12. As the restored code plate is pulled back by the springs 36 or 37 the projections 26 or 27 engage laterally the code plate rocker 14 and thereby displace the plate 12 within the slot 10. On release of the key lever 2 the plate 12 moves back to occupy a position in which the rocker 14 is again disposed above one of the projections 26 or 27. Case-shift mechanism; case-shift key actions. Upper case-shift.-To effect impression of an upper case character the depression of an upper case-shift key 118 precedes the depression of the upper case character key 4 and the rocking of an upper case-shift key lever 119 rocks an upper case bell-crank 124, which through a link 128, levers 132, 134 rocks a case-shift bell-crank 138 having a lug 140, Fig. 14, in an anticlockwise direction disengaging the lug from an abutting position with a lug 146 on a halfrevolution clutch constituted by spring-holder 144, Fig. 3, spring 150 and cam 156. The clutch drives a shaft 152 which displaces on the one hand a cam 206 which closes a main code contact group switch 210 and on the other hand a cam 172 which pivots an arm 176 about a pin 178 to raise a bail frame 188 on which are mounted the case-shift levers 90-1 . . . 90-7 to raise their lugs 94 into engagement with lugs 89 on the main code activating plates 84-1 . . . 84-7, whereby those activating plates which are displaced by their respective bails 74-1 . . . 74-7 rock the levers 90-1 . . . 90-7 to close contact switches 106 through the links 102, 104. Lower case-shift.-Depression of a lower caseshift key 214 rocks a link 218 which through a lever 222 and shaft 220 rocks a lever 226 which in turn rocks the bell-crank lever 138 in a clockwise direction to disengage the lug 140 from an abutting position with a lug 160 on the spring holder 144 to engage the shaft 152 for a further half-revolution displacement by the shaft 142. Rotation of the shaft 152 displaces on the one hand the cam 206 which now closes an auxiliary code contact group switch 214 and on the other the cam 172 which now pivots the arm 176 to lower the frame 188 on which the case-shift levers 90-1 . . . 90-7 are mounted to lower their lugs 94 into engagement with lugs 88 on the auxiliary code activating plates 86-1 . . . 86-7, which when displaced by their respective bails 76-1 . . . 76-7 rock. their associated levers 90-1 . . . 90-7 to close contact switches 106 through the links 102; 104. Middle case-shift.-Depression of the middle case-shift key 232 causes rotation, of a onerevolution clutch (not shown) which in. turn rotates a switching cam 244 acting on a follower 248 attached to a bell-crank lever 246 to pivot a shaft 247 and thereby rock a bail 264 in a clockwise direction through an arm 258 and link 260. The bail 264 slides the code switching plates 12 to place the lugs 24 of their associated rockers 14 over the protrusions 27 of the middle case code plates 8. The code plates 8 associated with the upper case code combination are provided with protrusions 64<SP>1</SP>-1 . . . 64<SP>1</SP>-7 and a depending lug 304 co-operating witha main code bail 310 so that on depression of a middle case character key the bail engages a lever 316 to pivot it and displace a lever 346 by toggle action. The lever 346 is articulated through a link 164, Fig. 14, to the bell-crank 138 whose lug 140 is disengaged: from the lug 146 to set the clutch rotating shaft 152 through 180 degrees into operation. The code plates associated with the lower code combinations are provided with protrusions 66<SP>1</SP> (not shown) and a depending lug 306, Fig. 16, co-operating with an auxiliary code bail 314, Fig. 3, actuating a lever 320 in a similar manner: Levers 316, 320 are operating the bell-crank 138 in a manner described above.