Patent GB-504501-A (GB)
Title: Printing telegraph automatic exchange system
IPC: H04L12/00
Filed: 1938-05-10
Abstract: 504,501. Telegraph exchange systems. STANDARD TELEPHONES & CABLES, Ltd. (Western Electric Co., Inc.) May 10, 1938, No. 13945. [Class 40 (iii)] Selecting mechanism, Fig. 3, responds to one or more permutation code combinations to select a line 343. This line is appropriate to one of a number of stocks, of which individual brokers can obtain the latest quotation. (The initial digit of a reference numeral indicates the Figure in which it appears.) The broker prints on his typewriter 201 the code letters of a stock and receives from keysets 402, 403 at a central station, Figs. 3-6, signals for the latest quotations which operate the typewriter. The signals received at the central station through a line finder 209 operate a printer 300, the pull-bars 302 .. of which close contacts A .. These contacts and an auxiliary line 203 are connected to switches 307 ... 320, which are stepped at each complete permutation. Thus one or more of relays 310 .. are selected according to the number and order of the characters transmitted. These relays select an appropriate single relay 333 .., which connects up the appropriate keyset 402, 403 through hunting switches 420 .. The attendant sets up the bid quotation on the keyset 402, the hundreds in row H, the tens in T, the units in U and the fractions in F. The asked quotation is similarly set up on the keyset 403. The individual key contacts 1 ... 9 are connected through the contacts of relays 406 ... 415, which control the set to be in operation, to distributers 500 ... 516, the segments of which are arranged to give the signals appropriate to the numeral. Each of the distributers 501 ... 509, corresponding to the numerals 1... 9, can transmit the numeral in three positions in each revolution, according to whether it is in the hundreds, tens, or units position. The distributers are driven by a motor 519 through friction clutches and are released in the following order by relays 525 ... 528 : digit distributers 500 ... 509, fraction distributers 510...516, space distributers 556, 557, digit distributers, fraction distributers, and wait distributers 518, 524. The signals sent by the distributers control a master sending relay 401 which repeats them to sending relays 430 . , . 439. The transmission begins at the first wait signal after the operation of a request key 202. The signal moves a switch, Fig. 6, one step. The second wait signal moves it another step and it is then continuously stepped to its alternate normal position. During this time a relay 611 deenergizes and a relay 319 releases the connection. If a second broker is asking for information of the same stock, a relay 357 operates in response to a relay 301 in the auxiliary, line and, because no ground can be obtained at the relay associated with the switch 420, shunts a stepper magnet 602. This prevents a release of the second broker's selecting mechanism during the time the first broker is receiving the information. Changing quotations. Pressing a change key 405 prepares a circuit through a relay 440, which is operated by the next wait signal and causes relays 417, 418 to release latches holding the post keys in position. It also releases relays 400, 401, and 430 ... 439, which close the quote line until a send key 404 causes the relay 400 to operate at the. next wait, signal. When the relay 401 releases, the operative sending relay 430 .. 439 closes a slowly operating relay 355, which ahunts the magnet 602 and retains the stepping switch in the second position until the next wait signal after the relays 430 ... 439 begin to respond.