US1497459A - Automatic telephone system - Google Patents

Description

ame 10 1924;

R. MERCER AUTOMATIC TELEPHONE SYSTEM 1 Filed March 12. 1921 inuen Ur- Emhard Harmer Patented June; 10, 1924.-

A 21,497,459 PATENT OFFICE.

RICHARD MERCER, OF LIVERPOOL, ENGLAND, ASSIC'NOR TO AUTOMATIC ELECTRIC COMPANY, OF CHICAGO, ILLINOIS,

A CORPORATION OF ILLINOIS.

.AUTOMATIC TELEPHONE srs'rma.

Ap'plicationflled March 12, 1921. Serial No. 451,903.

To all whom it may concern: Be it known that .I, RICHARD MERCER, a subject of the King of Great Britain and Ireland, and a resident of Liverpool, England, have invented certain new and usefu Improvements in Automatic Telephone Systems, of hich the following is a specification.

The present invention relates to improvements in or relating to telephone or like sys-' tems and has for its object improved arrangements whereby calls may be dealt with in their proper sequence. More particularly, the invention relates to arrangements in connection with interjunction wo1'ki11g between automatic and manual exchanges where the-calls from the automatic subsc'riber aresetup on register sets and subsequently brought to the attention of anoperator.

One ofthe features of the present inven tion is an arrangement whereby the calls are grouped into their proper sequence, that is, 1n the order in which they arrive prior to the operation of the register sets, while the stored up calls are. dealt with in turn by a step by step switching device which might either-consist of a mechanical step by step switch or.a chain of relays adapted to be operated in succession;

A second feature of theinvention consists of a novel arrangement for grouping the calls into a definite orderusing rotary line switches of the type which remains on the contact last used. A third feature consists of relay switching devices for automatically transferring the stored calls to an indicator or causing the illumination of lamps'to en= able the o erator to ascertain the junction seize reglster sets in setup. Fig. 4 represents the contact spring assembly of a relay employed in Figs, 1 and 3,

1 although it will iwiper 17 is resting Referring to Fig. 1, C represents a rota line switch of the type in which the wipers remain on the contacts last used which, it is assumed, is associated with a junction line,

he understood that this application is only ple, while B represents a register set of which only part is'shown. When the junction line is seized, the lead 11 is connected to earth,.by arrangements wellknown to those versed in the art, so that a circuit is closed through the back contact of armature 12 of relay 13, through relay 14 to battery. Relay 14 energizes and at its armature 15connects earth to one side of relay 13, while at its armature 16 it connects the wiper 17 through the back contact of armature 18 to the other side of relay 13 which is also connected to the magnet 19. The operation consequently depends upon whether the on an earthed contact or not. If it is rest ng on an earthedcontact, then the relay. 13 will be short circuited and the magnet 19 will be operated to advance the wipers one step, this operation will be repeated if the next contact wiper 17 comes in contact with is engaged, but eventually, however, an idle line will be reached when the wiper 17 will not rest on an earthed contact. Consequently, relay 13 will energize in series with magnet 19, magnet 19 will not, however, energize in this circuit owing to relay 13 having a high resistance. The energization of relay 13 at armature 18 connects earth to the test wiper 17, at armature 12 the earth on conductor 11 is connected through wiper 20 to relay 21 and-battery, at armature 22, relay 13 looks itself energized to lead 11. Relay 14 will fall back on the attraction of armature 12. The lead 23 is extended through armature 24 of relay 13 to wiper 25 and its corresponding contact,

armature 26 of relay 21 and its working contact, series relay 27 and magnet 28 of the first of a series of step by step switches adapted to register the number of theialling party. As soon as the subscriber, dials the digits which have to bedescribed byway of exam- I stored, earth im ulses are transmitted over I the lead 23, there y causing the energization of series relay 27 and magnet 28 which latter causes the wipers 29 and 30 to step round a number of steps corresponding to t e number of impulses transmitted over lead 23. On the first impulse, relay 27 is energized and the wiper 29 moved to the first step.

Wiper 29 thereby closes. a circuit for relay 31 which energizes and disconnects the mpulse lead at armature 32. The operat ng circuit is, however, maintained, through ar mature 32 and. its working contact. On the completion of the first series of impulses the relay 27 deenergizes, while. the relay 31 re mains energized' Consequently, the i m-" pulsecircuit is continued from armature 26 and its working contact through armature 32 and its working contact, armature 33 and its resting contact to the next step by step switch which-corresponds inevery respect. to'that just described and serves to record the second impulse. A similar arrangement of'relays. 31 and 27 is provided with this switch, which enables the impulse circuit to be transfe-rred'to a third switch when the previous digit has been completed. Consequently, as many digits may be stored as is desired. 1

On the relay 27 of the last digit switch fallingback an earth is placed on lead 34. This lead causes theenergization of relay 35 and also lights the register lamp 60.

The above circuit arrangements, which are disclosed in the pending application of -Martin'et al., Serial No. 367 ,850, filed March 22.

and suitable circuit connections.

tracing the chain circuit of the relays 21,

each of which corresponds to adifferent register set, that when-one relay .21 is ener-g.

gized, say the first relay, an earth may be traced through armature 38, lead 39 through each ofthe armaturesAO of the remaining relays 21 to all the contacts of thebank 37 except the second. Thus it will be seen that on a second call coming in, the wiper 17 of the switch used will'find earth on the con tacts corresponding to all register sets except the second, which, itmust consequently come to restupon.

The third call. coming in, even ifthe call on No. 1 register set has been attended to but No.2 is still awaiting attention, will be allocated to the third position and so on.

, Consequently,'every call coming in before others have been attended to will be arranged I in a definite order. If, however, only one call comes in at once, then the rotary switches seized will not have to hunt, as all contacts adapted to be swept over by 17 will be disconnected from earthr Consequently, it will be appreciated, that by this means, the calls will be arranged to seize register sets in the order in which they tact, armature 42 and its working contact,

resistance 43, relay 36 to earth. Although branch circuits are also closed for the other relays 36,'tli'ese branch circuits are opened at the back contact of armature 45 as soon as the first relay starts to pull up. Accordingly, only relay36 of the first register set will fully energize. On. energizing, this relay closes a locking circuit for itself at arma ture 44, at armature 15 it connects earth to a common lead connected similarly to the armature's 45 of the relays 36 of the other registersets, while at its, armature 41-6 it disconnects earth from all the other re lays 36.

Referring to Fig. 1, it will be seen that in the register set. taken by way of example, relay 36 also connects earth at its armature 47 to energize the relays '48, of which one is provided'for each of the switching units of a register set. The relays 48 are arranged to connect earth to the contacts selected-by the individual switchin units,wh'ich contacts are connected in multiple with the corresponding contacts of the other register sets, to a bank of lamps common to an operators po-.

\ sition. These lamps are arranged in sets side by side, one set for each switching unitrand have numbersthereon corresponding to the position of the contacts in theswitch banks. As one terminal of each lamp is permanently connected to battery, the'relays 48 on ener gizlng cause the number set up on the regis-' ter set to be immediately displaycdtbefore the operator, while the last relay 48 connects earth to the lead 49' which passes through the wiper 50V to the lead 51'to illuminate a lamp corresponding to the junction with which the rotary switch C is associated. The operatontherefore, sees the number of the party required and the lamp lit at the junction at the same time and therebyhas all the information necessary to enable her to complete the connection. Since, the arrange ment for displaying register numbers forms no-part of the present invention, it has not been considered necessary to show all the circuits concerned in detail,'but reference 'is made to the hereinbefore cited application of 36 of the first register set.

, and fifth.

with. In order to prevent any attention, the second register set had been taken into use and also the third, fourth Now on relay 36 of the first register set deenergizing, after the "operator had attended to the call, only the relay 36 of the second register set will be able to operate, as it will receive current from battery through armature 41 of relay 35 of the first register set and its resting contact through armature 42 15 of relay 35 of the second register set, resistance 43, relay '36, back contact of armature -46 to earth.

The energizing battery of the relays 36 of the third, fourth, fifth and sixth register sets hasbeen removed by the armatures 41 of the relays 35 of the second, third, fourth, Y

whichattention,

and fifth register sets, respectively, have calls stored up and awa'itin and battery is removed from tl ie common conductor at the back contact of armature 45' of relay 36 of the second register set as soon asthis relay starts to pull up, as already explained in connection with relay The second call is accordingly dealt'with as usual, after which on the deenergization of relay 35 of the second register set, the third call is switched over.

It will be assumed, that by now, two more calls have -come in on to the sixth and seventh register sets. The call coming on to the seventh register set removes battery at armature 41 0f relay 35 of that set, so

that if a further call comes in which will be allocated tothe first register set, the rela 36 of that register set cannot energize until the last register set has been dealt possibility of two calls being switched over-at once on to the indicator which might arise by one of the calling partles ceiver before beingattended to, the common lead connected to the armatures .45 is provided so "that the relay 36 of all positions except that in use will. be short ciircuited. i

It is also to be noted that this arrangement has the great advantage,'that if two parties are dialling and one should take a time to dial than the other, then it is possible to attend .to the one. who has completedhis dialling; first even although. he should be on the register in advance'of the other party; for instance, assuming two subscribers seize thesecond and third register sets,.but the subscriber who has seized the third register set completes his dialling in a much shorter time than the subscriber who has seized the second register set. The operator having dealt with No. 1 register set is then immediately switched onto No.

hanging up his re-- register set interrupts 3 register set as the' relay 35 of the second register set will not haveenergized; then if the'party on the second register set completes his number, he will have'preference over anyone using, the fourth register set,

while the subscriber on the fourth register set would be attended to next and the routine would go on in the same order as previously described.

In Fig. 4 the-arrangement of the spring contacts of the relay 36 are shown in operative relationship bywhich it would be appreciated that, on the relay releasing the operations take place in substantially the following order: Firstly the front contact of armature 45 breaks, then armature 46 makes contact; followed by armature 45 making contact with its back contact. I Or, considering the reverse operation, on the relay energizing, the back contact of armature 45 breaks first, after which. armature -16 breaks its contact and then armature 45 closes its make contact. Thisadjustment is necessary in order to avoid operating more than one relay 36 at the same time, as will doubtless be understood from the previous explanation.

In further explanation, however, it may be pointed out more particularly that it. is necessary to have the make contact of armature 45 close last, or after armatur'es 45 and 46 have separated from their back contacts, in

order to avoid grounding the common conductor by partially energized relays such as 36. before such relays are caused to fall back by the opening of the back contact of armature 45 or 46 of the relay 36 which completely energizes. As to the necessity of having armature 45 separate from its back contact before armature 46 breaks its contact, this adjustment becomes essential in a case where calls sixth, seventh, and first register sets, for example. W'hen the fourth register set is released, and relay 35 of such register set connects battery to relay 36 of the fifth register-set, battery is also connected by way of the back contact of armature 45' of this relay to relays 36 of the sixth, seventh, and first register sets. Relay 36 of the fifth the ground connection to relays 36 of the sixth and seventh register sets at its armature 46, so there is no particular danger of these relays pulling up,

butit does not interrupt the ground connection to'rclay 36 of the first register set.

Onthecontrary, the last mentioned relay interrupts the ground connection to the rela'y 36 of tlie'fifth register set: it is essential .35 register set and performs other similar easily made and are entirelyefl'ective in preventing the difficult mentioned. I

It will be appreciated, that the invention is equally applicable to, mechanical call in- 5. dicators, as to luminous call indicators, for instance, when a limited number of mechan ical call indicators are connected by means of rotary switches .to junction lines, then they may be arranged to close contacts. similar to the contacts closed by relay 35, when all the digits of the num; her have been registered; then a relay equiv alent to 36 will be energizedswhich would be energized in the order in which theregisters have been seized, as previously described.

This would effect the illumination of a lamp' local tov the'mechanicalcall indicator and the illumination of a lamp local to the particular junction line. Conveniently, lamps I such as 60 would be controlled by the relay 36 and not by the springs operated on the storage of a number, thereby indicating not only that a call is stored but that a call is stored and should be attended to next.

It will be appreciated, therefore, by means of the arrangement shown in Figs.'2 and 3,. .the calls are first graded into a proper order, provided that they are not coming in one at a time when no ordering would be so required, and they are subsequently. dealt 'with one at a time by means of relays and 36 and suitable interconnecting arrange -ments as shown. Relay 36 on energizing causes the energization of relays 48 inthe functions which have ferredto. i

Having now particularly described and ascertained the'nature of my invention and; 40 in what manner the same is to be performed,

I declare that what I claim is 1. In a telephone system,hunting switches, lines all normally selectable by'said switches, and means for causing the remaining lines to .be selected in rotation whenever one or more lines are in use.

2. In a telephone system, a plurality of lines, a plurality of hunting switches adapted to select and connect with said lines at so random, and guarding circuits efi'ective only when one or more lines are connected with for causing subsequently operated switches to connect with lines in regular order. 3. In a telephone system, a plurality of. lines, a plurality of hunting switches having access to said lines in common, each switch having wipers which normally rest on the last selected line, and guarding circuits effective when any line is in use to cause subbeen previously resequently operated switches to select other lines in regular rotation.

4. In a telephone system, a plurality of hunting switches, a plurality of lines accessible to said switches in common, all said lines being norinally available for selection, and means rendered effective when any line is selected for rendering all other lines unselectable except the line next inorder after the one selected.

5. In a telephone system, a plurality of hunting switches, a plurality of "lines acces sible to said switches in common, all said lines being normally available for selection, guarding circuits for renderingsaid lines unselectable, and a relay individual to each 7 line, each relay operating when its associated line isselecte'd' to close the guarding circuits. for another idle lines'except the line next in order.

i. The combination, with register sets all 801 normally selectable, of means .for causing said sets to be selected in rotation whenever more than one is used at the same time, and a consecution controller for causing registered calls to be switched over to a display device one at a time. 7. The combination, with register sets all normally selectable, of means for causing saidscts to be selected in rotation whenever a setis already in use, and a consecution controller for causing registered calls-to be switched over to a'display device in the order in which their registration is completed. provided only one register set at a time is occupied b 1 a completely registeredcall. 8. The com ination, with register sets all normally selectable, of means for causing said sets to be selected in rotation whenever a set is already in use, a consecution controller for causing registered calls to be switched over to a display device one at a time, and circuit arrangements in said controller establishing a definite order'of preference between register sets occupied by ful ly registered calls which is independent of 106 the order in which the registration of such calls is completed.

9. The combination; with register sets all normallyselectable, of means for causing said sets to be selected in.rotation whenever 110 a set is already in use, a consecution controller for causing registered calls to be switched over to a display device one at a time, and circuit arrangements in said con troller establishing a definite order of prefl16 erence between the register sets upon which fully registered calls are waiting and giving such register sets preference over register sets upon which the calls are only partially registered. r 10. The combination, with a plurality of register sets and means for operating them to register called telephone numbers, of a consecution 'eentroller for causing registered numbers to be switched over to a display de- 125 vice one at a time, said controller having circuit arrangements for establishing a definite order of preference between said regismemee ter sets with respect to the order in which any occupied register sets are associated with the display device, and means effective in case all the register sets become occupied at one time for destroying the established order of preference to permit all said register sets to be associated with said display device before any particular set, which ordi' to register called telephone numbers, of a start relay and a test relay individual to consecution controller for causing registered numbers to be switched over a display device one at a time, said controller comprlsmg a each register set, a circuit for each start relay closed when the associated register set is occupied by a completely registered call,'a circuit for each test relay connecting one terminal thereof to-one pole of the battery, each such circuit including contacts on the associated start relay and contacts on another start relay, a common circuit for connecfing the other terminals of all saidutest relays to the other pole of the battery, and contacts on each test relay except "the last included in said common circuit whereby each test relay except the last disconnects all-usu'cceeding test relays from the said other pole of the battery.

Signed by me at February, 1921.

Liverpool this 4th day of

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