US1498544A - Electrical selective system - Google Patents

Description

June 24, 1 9249 k c. B. FOWLE,

ELECTRICAL SELECTIVE SYSTmE Filed March 9. 1 920 Patented June 24, 19 24.

CLARENCE B. FOWLER, OF NEW YORK, N. Y., ASSIGNOR TQ WESTERN ELECTRIC COM- PANY, INCORPORATED, 01 NEW YORK, N. Y., CORPORATION OF NEW YORK.

ELECTRICAL SELECTIVE SYSTEM.

Application filed March 9, 1920. I Serial No. 864,553.

To all whom it may concern.

Be it known that I, Cmnnnon B. FOWLER, a. citizen of the United States, residin at New" York, in the county of New York, State of New York, have invented certain new and useful Improvements in Electrical Selective Systems, of which the follow ing is a full, clear, concise, and exact description.

This invention relates to electrical selective systems and more particularly to electrical selective systems for use in automatic or semi-automatic telephone exchange systems.

One of the objects of this invention is to provide in a system of this nature, a number indicating device adapted to be set under the control of an impulse sender and retained in its set position until released.

A further object of this invention is to provide an improved impulse circuit for controlling switches.

In accordance with one of the features of this invention a plurality of step-'by-step switches are adapted to be successively set in response tothe sending of a plurality of series of impulses from a common impluse transmitting means. A plurality of signals, preferablty one for each digit of the decimal system 0 notation are associated with each switch. In response and corresponding to the impulses transmitted by the impulse transmitting means, signals are actuated. Actuation of a key returns all the switches to ngrmal, thereby deenergizing the signals.

Another feature of the invention, while employed in this invention but not necessarily limited thereto, consists in interposing a quick-acting relay between an impulse relay and a slow-acting relay usually emloyed in connection with a selector switch or controlling an auxiliary switch or side switch associated with the selector switch.

The purpose of this nick-acting relay is to insure actuation of t e-auxiliary swltch at the proper'time;

For a 'more complete understanding of this invention, reference maybe made to.

the operation of selectori well-known type of step-by-step switcli, as

ior example that shown in the U. S.

ent No. 1,472,465 of Forsberg and deVignier, issued October 30, 1923. In the particular system shown, each switch may be provided with three sets of contact banks. For the purpose of this specification the lower, middle, and upper contact banks will be termed, restoring, switching and steering banks respectively. The brushes of the steer ing banks are slightly different from those of the restoring and switching banks in that they are. of the bridging type, that is, the brushes make-before-break in passing from one contact to thenext. To. each steering bank are connected, a plurality of signals preferabl one for each digit of the decimal system 0 notation; through each switching .bank an auxiliary. switching device, such as relay 31., is controlled;- and through each restoring bank, an operating circuit for restoring the switches to normal is controlled.

Each switch is provided with a motor magnet, M, M such as 30'; which operates under the control of the impulse sender to move its associated brushes such as 32, 33'

and 34. The motor magnet 30 first operates to control the signal corresponding to the I digit dialed and subsequently operates to restore the switch to normal.

Each auxiliary switch, herein shown as a' relay, such as 31, operates at the-end of each series of impulses to connect an impulse circuit to the succeeding switch. The actuation of relay 31 is controlled by slowto-relea'se relay 24, which is energized during the sending of impulses, and a quickacting relay 23, which operates in response to the first interruption of the impulse circuit to operate 'slow-to-rclease relay 24. Relay 31 is thus initially prevented from operating during the sending of each series of impulses b subsequent y by relay 24.

The nature of the invention is such that it is believed a clearer understanding thereof will be obtained from a description of the operation of the system shown and it will be so described.

It will be assumed, for thepurpose of illustration, that an operator having. access to a sender S desires to dial the number 2345. Having associated the sender'with the impulse relay 20, in anyiwell-known manner as by operating a key or inserting a plug the operation of relay 23 and in a jack (not shown but schematically indicated by'the contacts 10),'relay 20, and 1n turn slow-to-release relay 21, are operated. The operator then proceeds to send out impulses in accordance with the desired num-' ber. Assuming that the sender S is of the well-known rotary or dial type, 'two interruptions of the circuit for relay 20 will occur when digit,2 is dialed. Upon the first interruption of the contacts 18 of the sender S, the circuit forv relay 20 is opened and ed; battery. Magnet 30 in actuating moves the brushes of switch A. one step into engage'ment'with its first set of contacts. Re,- lay 23 in energizing completes a lockin circuit for itself and causes ground to be p aced on conductor 19, extending through the lower normal contacts of relay 31 to the strapped terminals of the switching bank 33 of switch A, thusshort-circuiting relay 31 and preventing its energization at this moment. This ground is supplied to conductor 19 through the outer rig t-hand contact of relay 26, the inner make contact of relay 23 and the left-hand normal contacts of relay 24, until relay 24 operates, whereupon this ground is supplied to conductor 19 through the left-hand alternate contacts of relay 24. The locking circuit for relay 23 includes the outer right-hand contacts of re lay 26, upper make contacts of relay 23, left-hand winding of relay 23, and the righthandcontact of relay 24. Relay 23 in energizing'a'lso completes a circuit for the energization of slow-to-release relay 24 which,

in energizing, maintains the ground on conductor 19 during the sending of each series of impulses. The circuit for the energizetion of relay 24 may be traced as follows: grounded battery, winding of relay 24, lower make-contacts of" relay 23, and outer right-hand armature and back contact of relay 26 to ground. In energizing, relay 24 opens the locking circuit for relay 23, thus insuring the immediate release of rela 24, when the impulses of each set cease. rdi- 'narily a-slow-to-release relay, such as 24,

which remains energized during the sending of the impulses and releases at the end of each series of impulses, is used to control the actuation of the -magnet for the side switch or switching device. lit has been neeaeca demonstrated that while relay 24 is essentially a slow-to-release relay, it is also somewhat slow-to-operate and if the impulses transmitted are not exact in character, relay 24 is apt not to function properly to control the actuation of the switching device (in this instance relay 31) associated with the selector switch; quick-acting relay 23 is, therefore, interposed between the impulse relay 20 and the slow-to-release relay 24. Upon the first interruption at the sender, relay 23 operates to control the actuation of relay 31, the control being subsequently transferred to the slow-to-release relay 24. At the secondinterruption of the circuit for relay 24, relay 20 again deenergizes in response to which motor magnet 30 is again actuated, thus moving the brushes 32, 33 and 34 a second step.

Following-the second interruption of the contacts at the sender S, relay 20 again energizes and since the dial has now returned to normal position, relay 20 is maintained energized for an appreciable time br until the operator has set the dial for the second digit. During this interval, relay 24 deenergizes thereby removing the ground from conductor 19 and permitting'the operation of relay 31 over a circuit extending from ground, winding of relay 31, brush 33, strapped contacts of the switching bank and resistance 35 to, grounded battery. Relay 31 in operating disconnects the impulse con ductor 29 from ma net 30 and connects it to magnet 40. The rushes of switch A remain upon the contacts to which they have been moved, and lamp 2 corresponding to the digit dialed is caused to glow over a circuit extending from grounded battery, contacts of key 27, left-hand normal contacts of rela 26, conductor 17, lamp 2, third contact of t e steering bank of switch A, and brush 34 to ground.

From the fore oing it is apparent-that the switches B. and D may be successively operated in a similar manner to indi cate the several digits, namely, 3, 4, and 5 dialed by the operator and thus an indication (2345) is set up in the bank of lamps corresponding to the digits dialed.

'lo extinguish the signals and return the switches to normal, restoring key 27 may be actuated whereupon all switches are simultaneously started in their movement to normal position. Actuation of non-locking key 27, removes the shunt from relay 26, thereby completing a 'circuit extending from grounded battery, through the winding of relay 26, conductor .17, lamp 2, third contact and brush 34 of switch A 'to ground. Parallel clrcuits to ground extending from conductor 17 through the remaining actuated signals and their associated contacts and brushes are ma ntained until all switches have reached their normal position. Relay 26 is enerstoring bank of each switch for the, motor magnet of each switch. Under the control of their respective motor magnets, the brushes of each switch are returned to normal position. the circuit for relay 26 is opened, whereupon relay 26 releases its armatures and the system is ready for the next operation.

What'is claimgd is:

1. In an electrical selective system, a num- *ber indicating device comprising a plurality of sets of signals, each set having one signal for each digit of the decimal system of notation, a train of switches, one for each set of signals, means for actuating certain of said signals when said switches are in their set positions, means including an impulse sender for sending a plurality of sets of impulses for settin said switches, an auxiliary switching evioe individual to each switch of the train, and means for successively actuating said auxiliary switching devices during the intervals between sets of impulses to associate the impulse sender with the succeeding switch of the train.

2. In an electrical selective system, a number indicatin device comprising a plurality of sets 0 signals, each set having one-signal for each digit of the decimal":

system of notation, a train of switches, one for each set or signals, means to actuate certain of said signals when said switches are in their set positions, .means including an impulse sender for sending a plurality of sets of impulses to set said switches, a relay whereby said relay is actuated at the cessation of the set of impulses 'for the switch being set and means whereby said relay when energized associates the impulse sender with the succeedin switch of the train.

3. In an electricalselective system, a -num-' ber indicating device comprising a plurality of sets of signals, each sethaving one signal for each digit of the decimal system of notation, a train of switches, one for each set of signals, means efiective when said switches are in their set position to actuate certain of said signals, means including an impulse sender for sending a plurality of sets of impulses to set said switches, a relay associated with eachswitch of the train, means efi'ective upon the cessation of eachset of impulses to energize the relay of the switch being set, means whereby said relay upon energizing associates the impulse sender with t e succeedin switch of the train, an mpulse relay, ant? means including a quick and slow acting relay associated with said mpulse relay for preventing 'the energizatlon of the'relay of the switch being set during the sending of a set of impulses.

4. In an electrical selective system, a number indicating device comprising a pluralityv In reaching normal, position of sets of signals, each set having one signal for each digit of the decimal system of notation, a train of switches, one for each set of signals, means to actuate certain of said signals when said switches are in their set ositions, means including an impulse sender or sending a plurality of sets of im ulses to set said switches, a relay associate with Y each switch of the train, means whereby the energization of said relay associates the impulse sender with the succeeding switch of the train a shunt circuit for said relay, completed upon the initial step of the switch being operated, and means for removing said shunt when said switch has been set to energize said relay to associate the impulse sender with the succeeding switch of the train.

5. In an electrical selective system, a number indicating device comprising a plurality of sets of si nals, each set having one signal for each di it of the decimal system of notation, a tram of switches, one for each setof signals, means including an impulse sender for sending a plurality ofsets of impulses to set said switches, means to actuate certain of said signals corresponding to the set positions of the switches, a relay associated with each switch of the train, means whereby said relay upon energization associates the impulse sender with the successive switch of the train and means effective acting relay associated with said impulse reindividual to each switch of the tram, means 1 av for preventing the ener ization of the relay of the switch being set uring the sending of a set of im uses, a release circuit for each of said switc es, and means for simultaneously closing .all of said release circuits. 6. In an. electrical selective system, an automatic. switch, a stepping ma net therefor, an auxiliary switch associate with said automatic switch, means including an impulse relay for transmitting a series of impulses to said stegping magnet, and a quickacting relay an a slow-acting relay associated with said impulse relay for jointly controlling the actuation of said auxiliary switch.

7 In an electrical selective system, an automatic switch, meansincluding an impulse relay for controllin said switch, a switchin device associate with said auto matic switch, a slow-acting relay associated with said impulse relay for controlling the 8. In an electrical selective system, an impulse sender, an lmpulse relay responsive vice until said slow-acting relay is energ zed.

to a Series of impulses from said sender, an automatic switch controlled by said impulse relay, a switching device associated with said switch, a slow-acting relay, means whereby the energization of said slow acting relay operates said switching device, a quick-- acting relay energized in response to the first impulse of the series to said impulse relay for energizing said slow-acting relay and means for deenergizing said slow acting relay to operate said switching device.

9. In an electrical selective system, an automatic switch, a stepping magnet therefor, means including an impulse relay for transmitting a series of impulses to said I stepping magnet, a switching device associated with said switch, a slow-acting relay associated with said impulse relay energized during the sending of a series of impulses aud deenergized at the end of a series of impulses, a quick-acting relay associated with saidfimpulse relay responsive to the first impulse of a series of energizing said slow-acting relay, and circuit connections controlled jointly by said quick-acting relay and said slow-acting relay for controlling the actuation of said switching device.

In witness whereof, I hereunto subscribe my name this 5th day of March A. I1, 1920.

GLARENCE B. FQVVLER.

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