Patent GB-960391-A (GB)
Title: Data transmission apparatus
IPC: H04L17/12
Filed: 1960-09-21
Abstract: 960, 391. Statistical apparatus; electric selective signalling. GENERAL TIME CORPORATION. Sept. 21, 1960 [Sept. 21, 1959], No. 32473/60. Headings G4H and G4M. In apparatus, Fig. 1, for transmitting data from a local position to a central station, some of the data being set up on switches 5 and some being read from record cards 66, the cards are sensed by feelers, one for each row of perforations, another feeler being provided to contact the card surface, relative movement between the latter feeler and any of the row-sensing feelers as they fall into perforations, causing corresponding contacts to close. The system may be used for example in a department store, data relating to each sale being transmitted to the central office and there punched into tape for further handling. As shown in Fig. 8 there are slots 66<SP>1</SP> to receive the cards and the sensing head 62 (dotted lines) is moved from right to left to sense the cards by a toothed band 102. After the sensing operation the head is returned to its initial position in readiness for the next transmission. The band 102 is driven by a motor 101 and the sensing head slides on parallel rails 61. Card mechanism:-The record cards, when inserted lie against a guideplate 67, Fig. 9A having side guides 67a for slide members 68 carrying a rail 69 on which the bottom edges of the cards rest. The slides are connected to move together by a horizontal bar which is lowered by energization of a solenoid 75, Fig. 28. The presence or absence of a card in each slot is tested by levers 84 Fig. 9A which close switches 87 Fig. 29 when a card is inserted. Relays A, B and C controlled by these switches have their contacts connected in a network 30 to the contacts of a switch 21a. The switch is adjusted according to the number of cards to be used and the machine will not start unless the cards inserted correspond to the setting of the switch. Before the slides are lowered, the card is clamped to them by a spring clamp Fig. 11 operated by rotation of a cam 82. These cams are mounted on a shaft 83 which is rotated in steps by energization of a solenoid 87a, Fig. 28 when the "transmit" button 7 is pressed. Rotation of a cam 82 also operates a switch 88 to energize the solenoid 75 which lowers the guide rail 69 so that the cards are drawn into the slots 66 and firmly held for sensing. As the cards are drawn into the slots their lower edges contact and engage levers which close switches 91 Fig. 28 which indicate that the cards are properly located. These switches are normally short-circuited by contacts 91a-91c of relays A, B, C, so that if any card is missing the corresponding switch 92 is rendered inoperative. Switches 91 are connected in series and control a relay 208. Sensing head. Fig. 18:- A vertical shaft 109 on the carriage 62 (Fig. 9A) carries sensing levers 113, 116, 119, Fig. 18. The central lever 113 is a reference guide having a finger 113a running on an unperforated strip of the card. It carries a contact block 105 which is adjusted in position by the lever 113 to accommodate different thickness of card. The perforation sensing levers 116, 119 &c. have fingers which enter the perforations 120. The consequential tilting of the lever causes a nose portion to close a contact 106, 107. As the sensing head makes its traverse, the cards are pensed in succession, column-by-column. To allow the return stroke to be made without damage, the sensing members are lifted from the card by rotation of a cam 110 Figs. 18A, 18B co-operating with arms on all the levers. The cam shaft 112 is rotated by contact with fixed abutments 127, 128 Fig. 8 at either end of its stroke. Rotation of this shaft also serves to rotate spring bail 108, Fig. 18A to alternately tension and release the spring 108a which applies the sensing pressure. The contacts 106 are energized through a switch 111b, Fig. 29 operated by a lever 111 similar to the levers 116 &c. but running on a cam strip so as to apply earth to the contacts only whenthe sensing levers are moving over the record cards. Other arrangements are also described. As the carriage 62 moves over its traverse, a number of switches such as 55, Fig. 8 are operated by cams 59. These serve control purposes. Instead of having moving sensing levers they may be stationary and the cards may be mounted on a rotating drum. Variable data switches - Extra data is set up on rotary switches controlled by knobs 5 Fig. 1. Each of these has a dial 27 presenting a digit at a window 4. Contacts 28, 29, Fig. 3 engage a printed circuit to select one of ten output leads in every position. A gear 31 is engaged by the pinion 32 on an electric motor 33, one for each switch which returns the switch to zero after each transmission operation. Switchtes 40-42 are operated as the switch is turned by cam sleeve 39. Switches 41, Fig. 28 are closed except when the switch is in zero position to enable the resetting motors to be energized when the reset relay 204 operates. The knob 5 is connected to the switch part through a clutch 25, 26 which is disengaged by rotation of shaft 34 to prevent alteration of the switch once transmission has started. The shaft 34 is controlled by a solenoid 37, Fig. 28, through parallel switches 42 which close when the associated switch leaves the zero position. Serialiser - The data from the dial switches 27 is read out by a switch 51, Fig. 29 which earths the switch wipers in turn and thereby applies earth to one of ten output leads in cable 200. The switch 51 is driven by a constantly running motor 53 through a clutch 53a engaged upon operation of relay 315. Data from switches 27 and switches 21b, 21c is read out in a predetermined order and followed by data from the cards. Operation - The desired combination of cards is inserted in the slots and the switch 21 set to correspond. This energizes relay 310, Fig. 28 to close contacts 320 and 241 so that when "transmit" button 7 is pressed coil 87a is operated to grip the cards and draw them down into the slots. When they are properly in position switch 99A opens, the cards being latched down by latch 90 and the circuit containing three switches 91 is completed to energize relay 208. This closes contacts 248, 249 and 207. The first calls the central office via cables 799, the second lights a "ready to transmit" lamp 276 and the last picks relay 37, closing contacts 243, 245. If the switches 87 are open as the result of removal of the cards a circuit through contacts 242 and 245 picks relay 204 to energize the resetting motors 33 and return the dials to zero. When the central station indicates that it is ready to receive the data relay 250 picks to close contact 251 operating solenoid 315 engaging clutch 53a and starting the switch 50. The first contact engaged by the arm 51 connects to a bank 21c of switch 21 and this sends a "length of message" digit. This is stored in the central station and compared with the number of digits sent to provide a check. Next, the bank 21b is energized to transmit a "data classification" digit which is recorded at the central station. The data from the cards and the dial switches 27 follows and the switch 50 is stopped by switch 18 when it returns to its initial position. Switch 17 also closes as the switch 50 approaches its home position to pick relay 253 and start the motor 101 driving the record card sensing head, the motor being controlled by switch 57 to reverse the head at the end of its sensing stroke and return it to home position. During the card sensing data is transmitted from the cards column-bycolumn by earthing one of the digit lines 200, only those columns being sent which correspond to the closure of contact 325 by the control cam. A similar selection of the data on the various switches may be made by opening and closing earthing switch 326 on switch 50. During the return stroke of the senser, the relay 250 is de-energized by the central station and when the sensing head reaches home position relay 253 de-energizes and the motor 101 stops. The release of relay 250 operates card release relay 221 which energizes coil 90 to release the latch 89 so that the cards rise up in their slots. In the event of an error this automatic release is prevented and release button 8 must be used. Additional information may be entered by buttons "+" (for add) and "-" (for subtract) Fig. 1. Button N restores them to their normal positions. Other information from outside apparatus may be connected via plug boards to the scanning switch 50. Specifications 801,647, 838,678, 960,392, 960,393, 960,394, and 960,395 are referred to.