US1504258A

US1504258A - Telephone-exchange system

Info

Publication number: US1504258A
Application number: US527071A
Authority: US
Inventors: William H Matthies
Original assignee: Western Electric Co Inc
Current assignee: AT&T Corp
Priority date: 1922-01-05
Filing date: 1922-01-05
Publication date: 1924-08-12
Anticipated expiration: 1941-08-12
Also published as: GB191391A; FR561963A

Description

Aug. 112 192%. LSiM-flfifi W. H. MATTHIES TELEPHONE EXCHANGE SYSTEM Filed Jan. 5, 1922 4 Sheets-Sheet 1 l.2.3.4.5.6 7. 8.9.! l. 5J4. l7- l8.

Aug 12 WM. LEMQW W. H. MATTHIES TELEPHONE EXCHANGE SYSTEM Filed Jan. 5, 1922 4 Sheets-Sheet z Mvemwv VIM/[07m h. Mai/Mes.

111111 LUME W. H. MATTHIES TELEPHONE EXCHANGE SYSTEM Filed Jan. 5 1922 4 Sheets-Sheet 5 WILLIAM H. MATTI-IIES, or HAoKnnsAoK, new JERSEY, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW NEW' YORY.

YORK, N. Y., A. CORPORATION OF runnrnonanxonanon SYSTEM.

Application filed January 5, 1922.

To all whom it may concern:

Be it known that 1, WILLIAM H. Mar. THIES, a citizen of the United States, residing .at Hackensack, in the county of Ber- 5 gen,'State of New Jersey, have invented certain new and useful Improvements in Telephone-Exchange Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to automatic telephone eXch-ange systems and more particularly to an arrangement for establishing interconnections between ofiices having different types of automatic telephone equipment. p

In full automatic telephone exchange systerns the calling subscriber is in every case equipped with a substation sending device by. means of which he may control automatic switches. This sending device may either control the switches directly as in the case of the well known step-by-step systems or it may position registers constituting part. of a central office sender, which central office sender is later utilized to govern the switches of the exchange. In systems which employ a central oilice sender it is usual to pr vide a plurality of such senders for the commen use of the selective switches. When a calling subscribers line is extended to an automatic switch, an idle sending, device is then associated with such switch and placed in condition to receive the registration of the wanted number from the substation sender.

A. subscriber in a step-by-step office is accustomed to dialing series of impulses one after another without intermission. It therefore follows that if he has operated a step-by-step switch or switches to select a trunk terminating in a switch arranged to be operated by a central oflice type sender, certain difliculties logically arise due to the fact that a certain amount of time is requi'red before a central office sender can be associated with the switch seized, and therefore if the subscriber dials at once, some of the impulses sent may be lost, since it is likely to occur that no registers are ready to receive impulses at the time he dials.

The same condition arises in case an operator, who is provided with a dial which she may connect to a cord circuit and who Serial No. 527,071.

' normally has access to step-bystep switches,

plugs into a trunk terminating in a switch arrangedfor operation by means of a con tral otlice sender. The operator is trai-netl and accustomed to dialing immediately af ter plugging into a trunk, and there is the same likelihood that impulses will belost due to the time required to connect a sender to the trunk which she has taken for use.

It is the object of this invention to provide a registering arrangement such that impulses may be transmitted over a trunk terminating in a switch controlled by a central omce sender immediately after such trunk has been taken for use without danger of the loss of impulses.

It is a further object of the invention to provide registering devices, some of which are individual to atrunk circuit, and others of which are common to a plurality of similar trunk circuits which may be suitably coordinated at the proper time to receive a complete designation.

An additional object of the invention contemplates a temporary registration on apparatus individual to a trunk circuit with a subsequent transfer of such registration toapparatus common to the trunk circuit.

It is a still further object of the invention to provide a trunk circuit having the above characteristics, which shall function properly in case of premature release and shall be immediately receptive to new registrartions following such premature release.

A feature of the invention resides in the use of a register switch individual to a trunk circuit'and the method of transferring the registration received thereon to a register which is common to a plurality of similar trunk circuits.

A further feature of the invention is at tained-by the use of release circuits for such individual register so as to render it available for reuse in case of premature disconnection.

Other features of the invention will be apparent from the following detailed description, reference being had to the accompanying drawings.

In the drawings so much of a telephone,- system is shown as is necessary to an under standing of the invention. Fig. 1 shows the circuits of a selector switch in which a trunk terminates, such trunk being accessible to step-bystep switches diagrammatically indicated.

Fig. 2 shows a registering device 111- dividual to the trunk circuit and a sender selector together with controlling circuits therefor.

Fig. 3 illustrates a registering and sending device which is one of a plurality, commonly accessible to switches of the type shown in Fig. 1, by means of the sender selector of Fig. 2.

Fig. 4 shows a final connector switch and controlling circuits therefor.

It has been assumed that the trunk leading to th switch shown in Fig. 1 has been seized by means of step-by-step switches under the control of a dial at a subscribers substation. It is of course obvious that the trunk might have been seized by a manual operator equipped with a dial which she may associate with her cord circuit. It

is also obvious that the invention is capable of many and various adaptations, and is therefore to be limited only by the appended claims. i

The selector switches shown in Figs. 3 and 1 are of the well known multiple brush, power driven type of a mechanical structure substantially similar to that shown in Patent No. 1,123,696, issued January 5, 1915, to E. B. Craft and J. N. Reynolds. These two switches in combination are arranged to serve 10,000 subscribers lines,

. in accordance with principles of numerical translation fully described in Patent No. 1,03,86,1, issued January 17, 1922, to A. E. Lunde-ll. The controlling sequence switches are substantially similar in construction and operation to the switch disclosed in Patent No. 1,127,808, issued February 9, 1915, to J. N. Reynolds and C. F. Baldwin.

The detailed operation of the system is as follows: The subscriber at substation 1 by removing his receiver from the switchhook puts into operation a line switch, generally indicated at 2, to select an idle trunk leading to a first selector. He then operates a dial 3 to send impulses to position a first selector to select the trunk shown in Fig. 1. The switch 2 may be any well known form of line switch, and the switch 4: is assumed to be any well known type ,of step-by-step switch. Since the operation of switches of this kind is well understood, it has not been considered necessary to describe their operation in detail. The subscriber by dialing the first impulse has now selected an office of 10,000 lines, in which the switches are ofl the well known power driven type. It is of course obvious that by the addition of a, switch corresponding to switch 4, the subscriber could select any one of one hundred offices. If he selects an oflice equipped with step-by-step switches,

the next four digits will be transmitted to a. second and third selector and a connector switch to establish the connection in a manner well understood.

In the present case it is necessary that the impulses be received on registering devices. It will be assumed that the wanted line number is 9876.

As soon as the trunk shown in Fig. 1 has been seized, acircuit is completed from grounded battery, winding of relay 5, Fig. 2, conductor 6, inner left-hand armature and back contact of relay 7, trunk conductor 8, and thence through

switches

1 and 2 and over the loop of the calling subscribers line, returning by way of switches 2 and 4: to trunk conductor 9, outer left-hand armature and back contact of relay 7 to ground. Relay 5 is energized in this circuit and completes, at its left-hand armature, -a circuit for slow release relay 10.

The calling subscriber now operates his dial to transmit nine impulses. Upon the first interruption of the line circuit relay 5 deenergizes and completes a circuit from ground, back contact and armature of relay 5, outer armature and front contact of relay 10, which being slow to release, remains energized during the sending of the series of impulses, inner armature and back contact 01'? relay 11, winding 01 slow release relay 12, winding of stepping magnet 13 to grounded battery. Stepping magnet 13 controls a step-by-step register switch, the brushes and contact banks oi which are shown below such magnet. This register switch, as well as the sender selector switch, controlled by magnet 14:, and the ste yby-step register switches of Fig. 3 may be of any desired construction, but are preferably of the type shown in Patent 1,472,465, issued October 30, 1923, to O. F. Forsberg and R. M. Devignier.

The circuit above described causes the energization of magnet 13, and when rclayv 5 is reenergized upon the completion of the first impulse, magnet 13 is deencrgized to advance the wipers controlled thereby one step. Relay 12 being slow to release, remains energized until the completion of the sending of the series of impulses. Relay 5 is intermittently actuated to cause the intermittent actuation of stepping magnet 13 until the series of nine impulses has been. received, at which time the register switch will be in its ninth off-normal position.

At the conclusion of the sending of the first series of impulses, line relay 5 remains energized for a relatively long period of time, thus allowing relay 12 to be deenergized.

Tt should be observed that as soon as the register brush 15 reached its first cit-normal position, a circuit for relay 11 was completedtrom grounded battery, right-hand "of realy 10 to ground. I

traced comprises a self-lnterrupting clrcuit non-inductive winding of relay 1'1, left-hand winding of relay 11, to ground. Relay 11 does not operate because at this timerelay 12 is operated and at its left-hand armature short circuits the operating winding of relay 11. Upon the deenergization of relay 12, relay 11 is energized and transfers the impulse circuit to the hundreds register of Fig. 3, which is controlledby stepping magnet 16.

It is to be observed that as soon as the trunk is taken for use, as evidenced by the energization of relay and the subsequent energization of relay 10, the sender selector controlled by magnet 14 is put into operation due to the completion of the following circuits. The energization of relay comletes a circuit from grounded battery, leftiand winding of relay 17, inner left-hand armature and back contact of relay 18, inner armature and front contact of relay 10 to ground. Relay 17 is energized in this circuit and at its left hand armature completes a circuit for relay 18. Relay 18 upon energization opens the previously traced energizing circuit for relay 17 but relay 17 remains energized provided that the sender selector brushes are not resting on terminals leading to an idle sender, due to the completion of a locking circuit by way of its inner. right-hand armature, test brush 19 and its associated contact to ground. Busy test terminals will be characterized by the presence of ground potential, as will be seen hereinafter, while test terminals leading to idle senders will be characterized by the absence of ground potential. Vith relays 17 and 18 energized, a circuit is completed from grounded battery, winding, armature and back contact of magnet 14, outer right-hand armature and contact of relay 17 contacts of relay 18 controlled by its inner left-hand armature and the inner armature and front contact The circuit just for magnet 14, which causes the sender selector to be advanced until an idle trunk is found, at which time relay 1'? is deenergized and opens the driving circuit of magnet 14 to bring the sender selector to rest. When relay 17 is deenergized, the original energizing circuit of relay 18 is broken, but this relay remains energized over alocking circuit by way of its inner left-hand armature. Ground potential is supplied by way of the right-hand armature and front con tact of relay 18, and the inner right-hand armature and back contact of relay 17 to the multiple test terminals corresponding to the sender which has been taken for use to render such sender non-selectable to'other sender selectors. The ground potentialsupplied to the test terminal engaged by brush 19 causes the energization of relay 21, Fig.

3, over a circuit extending from grounded battery, winding of relay 21, normal righthand contacts of relay 22, conductor 23 to ground. Relay 21 is energized and at its outer right-hand armature prepares a look ing circuit for itself including the winding of relay 22. Relay 22 does not energize at this time, however, since it is shunted by the direct ground at the contact of relay 18. The deenergization of relay 17 completes a circuit from grounded battery, winding of relay 20, outer left-hand armature and contact of relay 18, left-hand armature and back contact of relay 17 to ground. Relay is energized and connects through the various controlling leads to position relay registers in the sender. The energization of relay 20 also extends the impulse circuit to the stepby-step registers of the sender.

As soon as relay 20 is energized, which occurs as soon as the sender selector has found an idle sender, circuits are completed for transferring the registration set up on the thousands register to: the thousands register relays of Fig. 3. The circuits for. the register relays of Fig. 3 are as follows: from ground, left-hand winding of relay 24, left: and winding of relay 25, contact of sequence switch spring 26, conductor 27, sender selector brush 28 and its associated contact, outer left-hand armature and front contact of relay 20, register brush 29 and its ninth off-normal cont-act, conductor 30, low resistance 32, outer armature and front contact of relay 11 to grounded battery. Relay is marginal and would not have energized had high resistance 31 been in cluded in the above circuit. but since only the low resistance 32 was included, relays 24 and 25 are both energized and lock up through their right-hand windings by way of the inner right-hand armature and front contact of relay 21, conductor 33, contact of sequence switch spring 34 to ground. Relay 35 does not become energized since its circuit is opened at register brush 36, to which it is extended by way of sequence switch contact 37, conductor 38, sender selector brush 39 and its associated contact, and the outer armature and back contact of relay 40, the middle left-hand armature and front contact of relay 20. Relay 41 is energized in a circuit from ground, left-hand winding of this relay, sequence switch contact 42, conductor 43, sender selector brush 44 and its associated cont-act, inner armature and back contact of relay 40, thousands register brush 45 and its ninth contact, to grounded battery, at outer armature and front contact of relay 1].. Relay 41 upon energization locks up to grounded conductor 33 by way of the contacts of relay 21.

Since the above traced circuits for the register relays of the sender are completed simultaneously as soon as the sender selector relay 5, outer armature and front contact of "relay 10, inner armature and front contact of relay 11, inner left-hand armature and front con-tact of relay 20, sender selector brush 46 and its associated contact, conductor 47 winding of slow release relay 48,

" outer armature and back contact of relay 49,

conductor 50 and the winding of stepping magnet 16 to grounded battery. Hundreds register stepping magnet 16 is energized in this circuit as is slow release relay 48, which *remains energized until the completion of thesending of the impulses." As soon as the first impulse is completed, relay 5 is reenergized, causing the deenergization of relay 16 and the subsequent advance of the hundreds register switch. lNhen the complete series of impulses has been received, relay 48 is deenergiz ed and allows relay 49 to be energized over a circuit extending from grounded battery, resistance 51, winding of relay49, hundreds register brush 52, and an off-normal contact to ground. This circuit was in existence before, but relay 49 was not energized since its winding wasshort-circuited by a direct path to ground from resistance 51 by way of the inner armature and back contact of relay49, and the right-hand armature and front contact of relay 48. lVith relay 49 energized, the impulse circuit is extended to tens register stepping magnet 53, by way of the outer armature, and front cont-act of relay 49 and the outer armature and back contact of relay 54. Stepping magnet 58 is operated under the control of line relay 5 until the completion of the series of impulses, at which time the tens register has been advanced into its seventh position. During the sending of the series of impulses, relay 48' is energized as before and releases at the end of the series to allow the energization of relay 54 over a circuit extending y from grounded battery, resistance 55, winding of relay 54, conductor 56, tens register brush 57 and an off-normal contact to ground. This circuit was previously in existence, but relay 54 did not operate since its winding was short circuit-ed at the righthand armature and front contact of relay 48. With relay 54 energized, the impulse circuit is extended to units register stepping magnet 58 by way of the outer lefthand armature and front contact of relay 54, and the units register is positioned in a manner similar to that employed in setting the hundreds and tens registers.

Selection in the district switch, shown in Fig. 1, may start as soon as the thousands registration is complete, and occurs as soon as the calling subscriber starts to transmit the hundreds impulses. As soon as the subscriber starts to transmit the hundreds impulses, thus causing the energization of relay 48, a circuit is completed from grounded battery, upper contact of sequence switch spring 59, winding of relay 60, normal contacts of relay 60, left-hand armature and front contact of relay 48, upper contact of sequence switch spring 34 to ground. Relay 60 1s energized 1n this circuit and coinpletes a circuit from grounded battery, power magnet of sequence switch 61, upper left-hand contact of sequence switch spring 62, conductor 63, outer armature and front contact of relay 60 to ground, moving this sequence switch out of position 1 and into position 2.

lVith sequence switch 61 in position 2, a circuit is completed from grounded battery, winding of relay of Fig. 2, right-hand armature and front contact of relay 20, sender selector brush 71 and its associated contact, conductor 72, upper contact of sequence switch spring 73 to ground. Relay 70 is energized in this circuit and locks up by way of its inner right-hand armature to ground by way of thousands register brush 15 and an off-normal contact. Relay 70 at. its left armature completes an energizing circuit for relay 40. Relay 70 at its outermost right-hand armature completes a circuit from grounded battery, winding of thousands register stepping magnet 13, armature and contact of such magnet, register brush 74 and an associated off-normal contact to ground. The circuit of magnet 13 is self-interrupting and the thousands register is restored to its normal position. It is believed that this return of the register which received the first series of impulses immediately after the start of the sending of the second series of impulses is a novel arrangement in the art.

In position 2 of sequence switch 61, a. circuit is completed to start the selective operations of the district selector switch, shown in Fig. 1. This circuit extends from grounded battery, right-hand winding' of relay 64, conductor 65, lower right-hand contact of sequence switch spring 66, upper right-hand contact of sequence switch spring 67, resistance 68, conductor 69, outer armature and front contact of relay 40, brush 39 and its associated contact, conductor 88, lower contact of sequence switch spring 37, winding of stepping magnet 75, outer armature and back contact of the No. 0 counting relay, lower contact of sequence switch spring 42, conductor 43, brush 44 and its associated contact, inner armature and front contact of relay 40, conductor 76, resistance 77, lower contacts of sequence switch spring 78 to ground. Relay 64 is energizedvin this circuit and conipletes a circuit from grounded battery, power magnet of sequence switch 79, lower left-hand contact of sequence switch spring 80, outer armature and front contact of relay 64 to ground, moving this sequence switch out of position 1 and into position 2. As soon as sequence switch 79 leaves position 1, the original energizing circuit for relay 64 is broken, but this relay remains energized in a locking circuit extending from grounded battery, through its righthand winding, the right-hand contact of sequence switch spring 81, inner armature and front contact of relay 64, lower lefthand contact of sequence switch spring 66,

and thence to ground over the path previ- I ously described. Stepping relay 75 is energized in series with relay 64 and completes a circuit from ground, lower left-hand contact of sequence switch spring 73, armature and front contact of relay 75, right-hand contact of sequence switch spring 90, left hand contact of sequence switch spring 82, left-hand armature and front contact of relay 24, inner left-hand armature and back contact of relay 35, inner left-hand armature and front contact of relay 25, thence to the armature and back contact of the No. 4 counting relay and the winding of the No. 4 counting relay to gr-oundedbattery. The No. 4 counting relay is energized in this circuit and prepares a locking circuit for itself includingthe winding of the No. 4 counting relay in the well known manner. The No. 4 counting relay is'not energized due to the fact that its winding is shunted by the ground supplied at the armature and contact of the stepping relay. The complete set of counting relays has not been shown since their operation is well known in the art.

With the district sequence switch 79 in position 2, circuits are completed for accomplishing brush selection. With relay 64 energized, a circuit is completed from grounded battery, winding of updrive magnet 83, lower right-hand and upper lefthand contacts of sequence switch spring 84, outer armature and front contact of relay 64 to ground. The brush shaft is moved in an upward direction under the control of magnet 83, and as soon as, commutator brush 85 engages the first conducting seg ment of commutator 86, the locking circuit of relay 64 is extended to ground by way of the upper right-hand contact of sequence switch spring 66, conducting segment of commutator 86, brush 85 and upper righ hand cont-act of sequence switch spring 87,

thus shunting down stepping relay 75 and allowing 1n the well known manner the operation of the No. 4 counting relay. lVhen "commutator brush 85 engages an insulating segment of commutator 86, stepping relay 75 is energized to cause the energization of i the No. 3 counting relay. The advance of the'commutator brush causes the successive actuation of the counting relays until the the counting relays are opened at sequence switch spring 88, and these relays are re stored to their normal condition. The energization of the No. 0 counting relay also opens the fundamental circuit, and when.

brush 85 engages'an insulating segment of commutator 86, at which time the brush shaft will be accurately positioned for tripping a desired set of brushes, relay 64 is deenergized, opening at. its outer armature ing the brush shaftto rest. At the same the circuit of updrive magnet 83 and bring-" time, a circuit is completed from grounded battery, power magnet of sequence switch 79, upper contact of sequence switch spring 80, outer armature and back contact of re lay 64 to ground for moving sequence switch 79 out of position 2 and into position 3.

The sender sequence switch 61 is immediately moved out of position 3 and into position 4, provided that the hundreds register has been positioned. If the hundreds register has not been positioned, the sender sequence switch will remain in position 3 until the hundreds register has attained its complete setting. As soon as the hundreds register has been completely positioned, as evidenced by the release of slow release relay 48, a circuit is completed. from grounded battery, upper contact of sequence switch spring 59, winding of relay 60, normal confacts of relay 60, left-hand normal contacts of relay 48, upper left-hand contact of sequence switch spring 89, hundreds register brush 52, and an associated off-normal contact to ground. Relay 60 is energized in this circuit and completes a circuit from grounded battery, power magnet of sequence switch 61, upper left-hand contact of sequence switch spring 62, conductor 63, outer armature and front contact of relay 60 to ground for advancing sequence switch 61 out of position 3 and into position 4. As soon as sequence switch 61 leaves position3, relay 60 is deenergized.

With district sequence switch 79 in position 3 and sender sequence switch. 61 in po- .sition 4, the fundamental circuit is comis locked to the fundamental circuit over a path identical with that previously described. The energization of stepping relay at this time completes a circuit from ground, lower right-hand contact of sequence switch spring 7 3, armature and front contact of stepping relay 75, left-hand contact of sequence switch spring 90, right-hand contact of sequence switch spring 82, hundreds' register brush 91 and its eighth contact, conductor 92, left-hand armature and front contact of relay 41, thence to the armature and back contact of the No. 3 counting relay and the winding of the No. 3 counting relay to groundedbattery. The No. 3 counting relay is'energized and prepares a circuit for the No. 5' counting relay.

The energization of relay 64 in position 4 of the district sequence switch 79 again completes the circuit of updrive magnet 83 over a path identical with that previously described and the brush shaft is moved upward in a group selecting movement. It should the noted that in position 3 of the district sequence switch, an obvious circuit is completed for trip magnet 92 so that as soon as the brush shaft starts its group selecting movement, the fifth set of brushes is tripped into operative relation with the contact bank served by it. As the district shaft moves upwardly, commutator brush 98 intermittently engages conducting segments of commutator 94 to supply ground to hold the line relay energized while the stepping relay is shunted down. The counting relays are successively actuated as before, and when the No. 0 counting relay is energized, an obvious circuit is completed for moving sequenceswitch 61 out of position 4 and into position 6. The No. 0 counting relay opens the fundamental circuit and a moment later commutator brush 93 engages an insulating segment of commutator 94. Relay 64 is thereupon deenergized, opening the circuit of updrive magnet 83 and bringing the brush shaft to rest with the fifth set of brushes in operative relation to the fourth group of trunks served by it. The release of relay 64 causes the advance of se quence switch 79 out of position 4 and into position 5 by means of a circuit identical with that previously traced for moving the switch out of position 2 and into position 3 As soon as sequence switch 79 reaches po- 'sition 5, relay 64 is energized by means of a circuit completed through its left hand Winding and the lower contacts of sequence switch spring 95 to cause the advance of sequence switch 79 out of position 5 and into position 6 by means of a circuit completed at the lower left-hand contact of sequence switch spring and the outer armature and front contact of relay 64. If the first trunkin the selected group is busy, relay 64 completes a locking circuit for itself through its right-hand winding, right-hand contact of sequence switch spring 81, inner armature and front contact of relay 64, right-hand contacts ofsequence switch spring 96, test brush 97 and its associated contact to ground, the busy condition being indicated by ground potential on the multiple test terminals of trunks in a manner which will be apparent from the subsequent description.

In position 6 of sequence switch '79, with relay 64 energized, trunk hunting takes place, updrive magnet 83 being again energized by the completion of a circuit; controlled at the outer armature and contact of relay 64. The brush set is advanced over the group of terminals until an idle trunk is encountered, at which time no ground poten tial will be supplied to the test terminal engaged by brush 97. The locking circuit through the right-hand winding of relay 64 is therefore opened. Relay 64 is, however, maintained energized a moment longer, due to the completion of a circuit through its left-hand winding, the left-hand contacts of sequence switch spring 95, a conducting seg ment of commutator 98, commutator brush 99, upper contacts of sequence switch spring 84, outer armature and contact of relay 64 to ground. When commutator brush 99 engages an insulating segment of commutator 98, at which time the brush set will be accurately centered on the selected termi- 'nal set, relay 64 is deenergized and opens the circuit of updrive magnet 83 to bring the brush shaft to rest. At the same time relay 64 completes an obvious circuit for advancing sequence switch 79 out of position 6 and into position 7. As soon as sequence switch 79 reaches position 6%, ground potential is applied to the test terminal of the trunk seized by way of the lower left-hand and upper right-hand contacts of sequence switch spring 96 and test brush 97.

WVith sequence switch 79 in position 7, re lay 64 is again energized by means of a circuit through its right-hand winding, conductor 65, lower contacts of sequence switch spring 66, right-hand contact of sequence switch spring 100, brush 101 and its associated contact, conductor 102, resistance 103, upper left-hand contact of sequence switch spring 104 to ground. Relay 64 looks up by way of its inner armature and front con tact and the right-hand contact of sequence switch 81, and remains locked up in position 8 of sequence switch 79, to which position. the'sequence switch is advanced in an obvious manner as soon as relay 64 is energized.

In position 8 of sequence switch 79 and position 6 of sender sequence switch 61, the fundamental circuit is again completed to control brush selection at the final switch. This circuit extends from grounded battery, lower contacts of sequence switch spring 105, Fig. 4, right-hand winding of relay 106, lower contacts of sequence switch spring 107, lower left-hand contact of sequence switch spring 108, trunk conductor 109, brush 110 and its associated contact, the upper contact of sequence switch spring 111, resistance 68, conductor 69, outer armature and front contact of relay 40, brush 39 and its as sociated contact, conductor 38, left-hand contact of sequence switch spring 37, winding of stepping relay 7 5, outer armature and back contact of the No. 0 counting relay, lower contact of sequence switch spring 42, conductor 43, brush 44 and its associated contact, inner armature and front contact of relay 40, conductor 76, resistance 77, lower contacts 01"- sequence switch spring 78 to ground.

Relays

106 and 7 5 are energized in this circuit. Relay 106 completes a looking circuit for itself through its right-hand winding and the lower contacts of sequence switch spring 112, right-hand armature and front contact of relay 106, and the lower left-hand contact of sequence switch spring 107 to ground over the path described. At its left-hand armature relay 106 completes an energizing circuit for relay 113 from grounded battery, winding of such relay, right-hand contact of sequence switch spring 114, left-hand armature and front contact of relay 106, contact of sequence switch spring 115 to ground. Relay 113 is energized in this circuit and completes a circuit from grounded battery, power magnet of sequence switch 116, right-hand contacts of sequence switch spring 117 right-hand armature and front contact of relay 113 to ground. The sequence switch is advanced out of position 1 and into position 2, where in relay 106 remains energized over the path. above described. When the sequence switch leave-s position 11 the original energizing circuit of relay 113 is opened, but this relay is maintained energized in a locking circuit by way of the left-hand contact of sequence switch spring 114, the left-hand armature and front contact of the relay, and thence to,

ground at the contacts of sequence switch spring 96 by way of test brush 97 and its associated contact.

The energization of stepping relay 75 completes a circuit from ground, lower left-hand contact of sequence switch spring 7 3, armature and front contact of relay 7 5, righthand contact of sequence switch spring 90, upper left-hand contact of sequence switch spring 118, hundreds register brush 119 and its eighth contact, the armature and back contact of the No. 3 counting relay and the winding of the No. 3 counting relay to grounded battery.

With final sequence switch 116 in position 2 and with relay 106 energized, the high speed updrive magnet 120 is energized by way of the upper contacts of sequence switch spring 121 and the left-hand armature of relay 106 to cause the advance of the final brush shaft in a brush selecting movement. As soon as commutator brush 122 engages a conducting portion of commutator 123, the locking circuit of relay 106 is extended to ground at the final switch by way 01 the upper right-hand contact of sequence switch spring 108, commutator 123, brush 122, and the lower contact of sequence switch spring 104. Stepping relay 7 5 is sl'mnted down and allows the energization of the No. 3 counting relay. As the brush shaft is advanced, the stepping relay is interi'nittently actuated to cause the successive actuation of the counting relays until the No. 0 counting relay is energized, whereupon the fundamental circuit is opened. As soon thereafter as commutator brush 122 engages an insulated segment of commutator 123, the locking circuit ofrela-y 106 is completely opened, and this relay deenergizes, opening the cir cuit of updrive magnet 120 and bringing the brush shaft to rest in a position such that upon subsequent upward movement, the fourth set 01" brushes will be tripped. The deenergization of relay 106 completes a cir cuit from grounded battery, power magnet 116, lower contact of sequence switch spring 124, left-hand armature and back contact of relay 106 and contact of sequence switch spring 115 to ground for moving this sequence switch out of position 2 and into position 3.

In the sender the energization of the 0 counting relay completes an obvious circuit for moving the sequence switch 61 out or position 6 and into position 7. As soon as the sender sequence switch leaves position 6, the locking circuits of the counting relays are opened and these relays are deenergized. The sender sequence switch 61 is moved out of position 7 and into position 8, provided that the tens register has been completely positioned. After the sending of the series of impulses which positions the tens register, slow release relay 48 is deen ergized and completes a circuit from grounded battery, upper contact of sequence switch. spring 59, winding of relay 60, normal contacts of relays 60 and 48, upper righthand contact of sequence switch spring 89, conductor 56, ofl -noraml contact 57 to ground. Relay 60 is energized and completes a circuit for the power magnet of sequence switch 61 by way of the upper lefthand contact of sequence switch spring 62 for advancing the switch out of position 7 and into position 8 With sequence switch 61 in position 8 and final sequence switch 116 in position 3, the fundamental circuit is again completed over a path identical with that described in connection with brush selection. As before, relays 106 and 7 are en ergized, and relay 106 completes a circuit from grounded battery, power magnet of sequence switch 116, lower contact of sequence switch spring 125, upper left-hand contact of sequence switch spring 121, lefthand armature and front contact of relay 106 to ground at the contact of sequence switch spring 115 for moving this sequence switch out of position 3 and into position 4. In position 1 of the final sequence switch, relay 106 is locked to the fundamental circuit by means of circuits similar to those which ac complished this in position 2 of the final sequence switch.

In the sender the energization of stepping relay 75 completes'a circuit from ground, lower right-hand contact of sequence switch spring 73, armature and front contact of relay 75, lower left-hand contact of sequence switch spring 90, upper right-hand contact of sequence switch spring 118, tens reglster brush 126 and its seventh contact, armature and back contact of the No. 7 counting relay and the winding of the No. 7 counting relay to grounded battery. The No. 7 counting relay is energized in this circuit and prepares a locking circuit for itself including the winding of the No. 7 counting relay. As soon as commutator brush 127 engages a conducting portion of commutator 128, stepping relay 7 5 is shunted down and the No. 7 counting relay is energized. At this time thelocking circuit of relay 106, extends by way of the upper right-hand contact of sequence switch spring 107 ,aconducting seg ment of commutator 128, brush 127 and the lower contact of sequence switch spring 10st to ground, it being observed that the circuit of the high speed updrive magnet is. controlled at the armature and front contact of relay 106 in the same manner as for brush selection. As soon as sequence switch 116 reached position 3, an obvious circuit for trip magnet 129 is completed, so that upon upward movement of the brush shaft, the fourth brush set is tripped into operative relation with the contact bank served by it.

As the brush shaft is advanced in a group selecting movement, the successive engagement of insulating and conducting segments of the commutator 128 by brush 127 causes the intermittent shunting down of stepping relay 7 5, and the resultant successive actuation of the counting relays. When the 0 counting relay is energized the funda mental circuit is opened, and when, a 1110- inent later, commutator brush 127 engages an insulated segment of commutator 128, relay 106 is deenergized and opens the cir cuit of updrive magnet 120 to bring the brush set to rest in operative relation to the terminals in the eighth group of contacts served by it. The energization of the 0 counting relay causes the advance of the sender sequence switch out of position 8 and into position 9. The deenergination of relay 106 causes the advance of the final sequence switch 116 into position 5 by means of an obvious circuit controlled at its lefthand armature and back contact.

As soon as sequence switch 61 reaches position 9, provided that the units register has been moved out of its normal position, an energizing circuit for relay 120 is completed by way of the contact of sequence switch spring 130, units register brush 131 and an associated off-normal contact to ground. Relay 129 at its middle right-hand armature supplies ground by way of hundreds register brush 182 and an otl-nor1nal contact to the back contact, armature and winding of stepping magnet 16. Stepping magnet 16 advances the hundreds register into its normal position whereby the ground controlled at the armature of relay 129 is extended by way of hundreds register brush 132 and its normal contact, tens register brush 136 and an oil-normal contact to the contact, arn'iature and winding of tens stepping magnet 53. Tens stepping magnet 53 causes the advance of the tens register into its normal position.

As soon as the units register has been completely set, as evidenced by the deenergized condition of relay 418, a circuit is completed from grounded battery, upper contact of sequence switch spring 59, winding of relay 60, normal contacts of relays and 18, lower contact of sequence switch spring 89, units register brush 131 and an off-normal contact to ground. Relay 60 is energized and completes an obvious circuit for advancing sequence switch 61. out of position 9 and into position 10.

lVith sequence switch 61 in position 10 and iinal sequence switch 116 in position 5, the fundamental circuit again completed as previously described, "ausing the energization of relays and 75. the energization of relay 106 causes the advance of sequence switch 116 into position 6 over a circuit identical with that which moved itfrom position 3 to position -l-. Relay 106 upon energization locks up to the fundamental circuit in a manner identical with that previously described. The energization of relay 7 5 completes a circuit from ground, lower left-hand contact of sequence switch spring 78, armature and front contact of relay 75, lower right-hand contacts of sequence switch springs 90 and 118, units register brush 134 and its sixth contact,

Inn

iterate armature and back contact of the No. 6 counting relay and the winding of the No. 6 counting relay to grounded battery. The No. 6 counting relay is energized and prepares a locking circuit for itself including the winding 01 the No. 6 counting relay.

Relay 106 remains energized in position 6 of sequence switch 116 by means of a locking circuit, and completes a circuit for low speed updrive magnet 135 by way or the upper right-hand contact of sequence switch spring 125 and the upper left-hand contact of sequence switch 121 to ground, thus causing the selected brush set to be advanced over the terminals in the selected group. As soon as commutator brush 122 engages a conducting segment of commutator 136, stepping relay 75 is shunted down and allows the No. 6 counting relay to be energized. At this time relay 106 is locked to ground by way of the upper right hand contact of sequence switch spring 108, a conducting ortion of commutator 136, brush 122 an the lower contact of sequence switch spring 104. The successive engagement of conducting insulating segments by brush 122 causes the intermittent operation of stepping relay 75 and the successive actuation of the counting relays. When the 0' counting relay is energized, the fundamental circuit is opened, and when, .a moment later, brush 122 engages an insulated portion of cominutator 136, relay 106 is deenergized, opening the circuit of driving magnet 135 and bringing the brush set to rest in engagement with the seventh line in the selected group.

The energization of the No. 0 counting relay completes an obvious circuit for advancing the sender sequence switch 61 out of position 10 and into position 14. When the sender sequence switch leaves position 13, relay 129 is deenergized.

When relay 106 is deenergized it completes an obvious circuit for moving sequence switch 116 out of position 6 and into position 87 In position 8, relay 106 is ei'iergized by means of a circuit from grounded battery, through its left-hand winding, the lower right-hand contact of sequence switch spring 138 and the right-hand armature and front contact of relay 113 to ground. Belay 106 is energized and completes a circuit from grounded battery, power magnet 116, lower contact of sequence switch spring 125, upper left-hand contact of sequence switch spring 121, left-hand armature and front contact of relay 106 to ground. Sequence switch 116 is advanced into position 13 under the control of the above circuit, and relay 106 is deenergized as soon as the sequence switch leaves position 8 provided the called line is idle. With relay 106 deenergized, sequence switch 116 is immediately moved into position 14,

which is the talking position, by means of a circuit extending from grounded battery, power magnet of sequence switch 116, the lower contact of sequence switch 124, back contact and inner left-hand armature of relay 106, to ground. 7

In case the called line is'busy which condition is indicated by the presence of battery potential on the test terminal of the line, relay 106 does not deenergize when sequence switch 116 leaves position 8. This is due to the fact that in position 8 of sequence switch 116, a circuit is completed from ground, right-hand contact of sequence switch spring 139, winding of test relay 140, upper contacts of sequence switch spring 141, righthand armature and front contact of relay 106, conductor 142, upper contactsv of sequence switch spring 112, test brush 144 and its associated contact to grounded battery. Test relay 140 is energized in this circuit and completes a locking circuit for relay 106 from grounded battery, lower contact of sequence switch spring 105, right-hand winding of relay 106, lower right-hand contact of sequence switch spring 10?, upper left hand contact of sequence switch spring 108, and armature and front contact of relay 140 to ground. Relay 106, therefore, remains energized until sequence. switch 116 reaches position 13. With relay 106 energized in position l3, acircuit is completed from grounded battery, winding of downdrive magnet 145, lower right-hand and upper lefthand contactsof sequence switch spring 121, left-hand armature and front contact of relay 106 to ground. The brush shaft is returned to its normal position under the con trol of magnet 145, and when it reaches its normal position, a circuit is completed from grounded battery, power magnet 116, upper right-hand contact of sequence switch spring 124, normal commutator segment 146, commutator brush 147, lower right-hand contact of sequence switch spring 104 to ground for advancing the sequence switch into position 17. In position 17 relay 106 is intermittently operated under the control of its left-hand winding by means of an interrupter 148 to which a circuit is extended by way of the lower left-hand contact of se quence switch spring 138. The operation of relay 106 intermittently supplies busy tone to the calling subscriber. This circuit extends from'ground, through the secondary winding 149 of a coil whose primary winding is connected to an interrupted source of alternating current, upper right-hand contact of sequence switch spring 150, upper contacts of sequence switch spring 105,1ower contacts of sequence switch spring 112, right hand armature and front contact of relay 106, conductor 142, lower right-hand and upper left-hand contacts of sequence switch spring 143, conductor 102, selector brush 101 and its associated contact, left-hand contact of sequence switch spring 100, the Winding of supervisory relay 151 and the lower righthand winding of repeating coil 152 to grounded battery. The current induced in the other windings of the repeating coil is then transmitted to the telephone of the calling subscriber to inform him that the line called is busy. He then replaces his receiver and causes the release of the selector, shown in Fig. 1, in a manner to be hereinafter described. When the selector switch shown in Fig. 1 disengages the terminal set leading to the'final switch shown in Fig.4, the circuit ofre'lay 113 is opened and this relay deenergizes, completing a circuit from grounded battery, power magnet 116, upper right and lower left contacts of sequence switch spring 117, right-hand armature and back contact of relay 113 to ground for moving this sequence switch out of position 17 and into position 18, from which position it is immediaitely moved by a circuit closed through the normal commutator segment 146 and returned to position 1, thus leaving the switch in its normal position.

It will be assumed, however, that the called line was idle and that therefore the final sequence switch came to rest in position 14, which is the talking position. At this time the

trunk conductors

109 and 102 are e. tended'through to the called substation at contacts controlled by sequence switch springs lOS and 143 by means of brushes 153 and'154 and their associated contacts.

It will be remembered that line relay (34 of the incoming selector switch, shown in Fig. 1, at the time sequence switch 79 reached position 8, was energized by means of a circuit completed at the upper left-hand contactof'sequence switch spring 104, Fig. 4. i As soon as sequence switch 116 leaves position 7 irelay 64 is deenergized and completes a circuit by way of its outer armature and back contact and the upper contact of sequence switch spring 80 for moving sequence switch 79 outof position 8 and into position 9.

A circuit is then completed from grounded battery, right hand windingof relay 64, upper contacts of sequence switch spring 81, resistance 77, conductor 7 6, inner armature and front contact of relay 40, brush 44 and its associated contact, conductor 43, lower contact of sequence switch spring 42, outer armature and back contact of the No. 0 counting relay, winding of stepping relay 75, left-hand contact of sequence switch spring 37, conductor 38, outer armature and front contact of relay 40, conductor 69, resistance 68, upper right-hand contact of sequence switch spring 67, upper left-hand contact of sequence switch spring 66 to ground. Relays 64 and 75 are energized in this circuit, the energization of relay 75 being, however, without effect. The energization of relay 64 completes a circuit from grounded battery, power magnet 79, lower left-hand contact of sequence switch spring 80, outer armature and front contact of relay 64 to ground for moving the sequence switch 79 out of position 9 and into position 11.

A circuit is now completed from grounded battery winding of relay 7, conductor 155, middle armature and front contact of relay 70, conductor 156, left-hand contacts of sequence switch spring 96 to ground. Relay 7 is energized in this circuit and locks up through its right-hand winding to the ground supplied at contacts of spring 96. Relay 7 at its left-hand armatures extends the subscribers substation line to repeating coil 152, and at the same time opens the circuit of line relay 5, causing the deenergization of relay 10 and the resultant dcenergization of relay 18, which in turn causes the deenergization of relays 20, and 40. As soon as relay 18 is deenergized, ground is removed from conductor 23 and relay 22 is energized since the shunt about its winding is now removed. The energization of relay 22 causes the deenergization of relay 21. Relay 22 is, however, locked up in a circuit from ground, left-hand ar1na ture and contact of relay 22, its left-hand winding, right-hand armature and front contact of relay 22, right-hand non-inductive winding of relay 22, lower contact of sequence switch spring 59 to grounded battery. Relay 21 upon deenergization completes a circuit from grounded battery, winding, armature and back contact of units reglster stepping magnet 58, units register brush 137, and an off-normal contact, outer right-hand armature and back contact of relay 129, tens register brush 133 and a normal contact, hundreds register brush 132 and a normal contact, outer armature and back contact of relay 21 to ground. Stepping magnet 58 interrupts its own circuit and causes the advance of the units register into its normal position. \Vhen the units register is completely restored, a circuit is completed from grounded battery, power magnet of sequence switch 61, upper right-hand contact of sequence switch 62, brush 137 and a normal contact, outer right-hand armature and back contact of relay 129, brush 133 and a normal contact, brush 132 and a normal contact, outer armature and back contact of relay 21 to ground for moving sequence switch 61 out of position 14 and into position 1 which is its normal position. When the sequence switch leaves position 183 relay 22 is deenergized. It should also be observed that the dccnergizatiou of relay 21 allowed such of the register relays 24, 25, 35 and 41 as have been energized to be released. The sender is now in its normal conltlt) ltlT:

dition and is ready for reuse. It should be noted that during the return of the sender sequence switch and the restoration of the units register, ground is supplied to conductor 23 by way of the left-hand armature of relay 22, through the winding of such relay to render the sender non-selectable to any sender selectors which may be in operation.

The release of relay 70, Fig. 2, completes a circuit from ground, through the armature and back contact of relay 70, left-hand contacts of sequence switch spring 157, power magnet of sequence switch ,7 9 to grounded battery for moving this sequence switch out of position 11 and into position 13, which is one 01'' two ringing positions.

The system is arranged for selectively ringingion tour party lines in accordance with the principles set forth in Patent No. 1,218,804, issued March 13, 1917, to F. N. Reeves. As shown insuch patent either positive or negative ringing current may be supplied to the line in accordance with which group has been selected at the in coming switch. Segments on the commutator indicated at 158 and 159 determine the polarity of ringing current. Transposition of the line wires at the final multiples on the well known terminal per station basis determine to which side oi the line ringing current is to be supplied. Since this method of selective ringing is well known, it will not be described in detail and it will be assumed that ringing current is supplied in position 13 of sequence switch *7 tion o't' relay caused a circuit to be com pleted for slow release relay 160. lllhis circuit extends from grounded battery, righthand winding of relay 160, inner armature and back contact of relay 161, upper left hand winding of repeating coil 152, lower contacts of sequence switch spring 67, inner left-hand armature and front contact of relay '4', and thence over the loop of. the :alling subscribers line, returning by way of conductor 9, outer right-hand armature and left contact of relay 7, upper contacts of sequence switch spring 78, lower lefthand winding of repeating coil 152, outer arutiature and bacl: contact of relay 161, lefthand winding of relay 160 to ground. Relay 160 is energized in this circuit and completes an alternate locking circuit for relay 7. At the same time relay 64 is energized due to the closure of a. circuit from ground ed battery through the right-hand winding of relay upper right-hand contact of s quence swit-h spring 16; armature and frontcontact oi? relay 160 to ground. Rela ized in this circuit and locks way of conductor 163, armature and contact of ringing trip relay 164, left handcontacts of sequence switch spring 84, outer armature and front contact of relay 64 to ground. This locking circuit of relay 64 is maintained in position 13 of sequence switch 7 9.

With sequence switch 79 in position 125, positive ringing current is supplied to the bells at the called station from a source of ringing current 165, left-hand winding of. trip relay 164, right-hand contact of sequence switch spring 166, inner armature and front contact of relay 64, upper righthand cont-act of sequence switch spring 100, brush 101 and its associated contact, conductor 102, upper contacts of sequence switch spring 143, brush 154 and its associated contact, and thence to ground through the bells at the substation. Ringing current is applied until the called subscriber answers, allowing the direct current to flow to energize trip relay 164. The energization of relay 164 opens the locking circuit of relay 64, and this relay deenergizes and disconnects the ringing current from the line and at the same time completes a circuit by way of the upper left-hand contact of sequence switch spring 80 and the outer armature and back contact 01 relay 64 for advancing the sequence switch YE out of position 13 and into position it. When sequence switch 79 reaches position 13%}, relay 64 is energized by a circuit com pleted through its right-hand winding and the upper right-hand contact of sequence switch spring 162, and the armature and front contact oi relay 160. Relay 64 re mains energized in position 14 of the sequence switch. The connection is now com-- plete and the. subscribers may converse.

It should be observed that when the called subscriber answers with sequence switch 79 in position 14, supervisory relay 151 is energized over the loop of the called subscribers line due to current flowing through the battery associated with the right-hand windings of repeating coil 152, which battery is also utilized tor supplying talking current to the called substation. The energization of relay 151 causes the energization of relay 161, which reverses the direction of. current flow over the incoming line for the purpose of operating supervisory signals or toll devices at the distant oflice. Relay 160 being slow to release, remains energized while relay 161 shifts its armatures.

After the conversation has been completed and connection is no longer desired, the subscribers replace their receivers. The opening of the substation circuit ot the calling subscriber causes the deenergization of relay 160 and the subsequent release of relay 64. Relay 64 upon deenergization completes a circuit from grounded battery, power magnet of sequence switch 79, upper left-hand contact of sequence switch spring 80, outer armature and back contact of relay 61 to ground, for moving this sequence switch out of position 1 1 and into position 18.

In position 18 of the sequence switch, downdrive magnet 167 is energized in an obvious circuit to cause the selector brush shaft to be restored to its normal position.

l/Vhen the brush shaft reaches its normal position, a circuit is completed from grounded battery, power magnet of sequence switch 79, lower right-hand contact of sequence switch spring 80, normal commutator segment 168, commutator brush 99, upper right-hand contact of sequence switch spring 8? to ground, for moving this sequence switch out of position 18 and into position 1 which is in its normal position.

As soon as the selector switch leaves the terminals of the trunk .leadingto the final switch, the locking circuit oi relay 113 is opened and this relay deenergizes, completing a circuit from grounded. battery, power magnet 116, upper right-hand and lower left-han d contacts of sequence switch spring 117, right-hand armature and back contact of relay 113 to ground for moving this quenoe switch out of position 14 and into position 18. In position 18 otsequence switch 116, a circuit is completed from grounded battery, winding of downdrive magnet 1415, lower right-hand and upper lett hand contacts of sequence switch spring 121, contact of sequence switch spring 168 to ground. Magnet 1 15 is energized and causes the return of the final selector. During the return of the final selector switch, busy ground is supplied to the multiple test terminals of the trunk by way of sequence switch spring 139 and the armature and back contact of relay 118. When the switch reaches its normal position, a circuit is completed from grounded battery, power magnet of sequence switch 116, upper righthand contact of sequence switch spring 124, normal commutator segment 1 16, commutator brush 14:7, and. the lower right-hand contact of sequence switch spring 10-1 to ground for advancing the sequence switch into its normal position. All parts of the apparatus have now been restored and are ready for reuse.

What is claimed is:

1. In a register system, an automatic switch, an impulse circuit, a plurality of registering devices arranged for control .over said impulse circuit, certain of said registering devices being permanently associated with said circuit, means whereby others of said registering devices are temporarily associated with said circuit, means to position said registers, and means to operate said automatic switch under the control of said registering devices.

2. In a telephone exchange system, an automatic switch, a plurality of registering devices, means to selectively position said registering devices, and means to variably operate said automatic switch in accordance with the setting of said registering devices, a portion only of said plurality oi? registering devices being individual to said switch, and means to render the remaining portion of said registering devices commonly available to said switch.

In a telephone exchange system, a train of automatic switches, a series of registering devices, means to set up a complete multidigital registration on said registering devices, the first of said series of registering devices being individiuil to the first switch of said train of switches, and means to render the others oi said series of registering devices commonly available to a plu rality of like switches, and means to operate said train of automatic switches under the control of said registering devices.

41. In a telephone exchange system, a plurality of automatic switches, a sending device common to said automatic switches, means to operate a desired one of said automatic switches under the control of said sending device, registering devices, certain ones of said registering devices being individual to said automatic switch, and others being individual to said sending device, means to position said registering devices, and means to variably operate said sending device in accordance with the positions assumed by said registering devices.

5. In a telephone exchange system, a link circuit for extending the subscribers talking connection, a registering device individual to said link circuit, a plurality of senders commonly available to said link circuit, each of said senders including a registering device, means to associate one of said. senders with said link circuit, means to position said individual registering device, means to transfer the registration thus acconn'ilished to a registering devii-e of the associated sender, an automatic switch, and means to position said automatic switch under the control of said associated sender.

6. In a register system, an impulse circuit, a registering device individual to said impulse circuit, a plurality of res" itcring devices commonly available to said impulse circuit, means to associate a common registering device with said impulse circuit, means to position said individual registering device by means of impulses transmitted over said impulse circuit, and means operative thereafter to transfer such registration to said associated common registering device.

7. In a register system, an impulse circuit, a registering device individual to said lOO impulse circuit, a plurality of equivalent registering devices, means to render said equivalent registering devices commonly available to said impulse circuit, means to posit-ion said individual registering device by means of impulses transmitted over said impulse circuit, means to transfer such registration to a common registering device, and means operative thereupon to restore said individual registering device to its normal position.

8. In a register system, an impulse circuit, means to transmit a plurality of series of current impulses thereover, a registering device individual to said circuit, a plurality of such registering devices, means to render said plurality commonly available to said circuit, means to simultaneously posi tion said individual registering device and to associate an idle set of registering devices with said circuit, and means to transfer the registration thus accomplished from said individual registering device to a reg istering device common to said circuit.

9. In a register system, an impulse circuit, a registering device individual to said circuit, a plurality of equivalent registering devices, means to render said equivalent registering devices commonly available to said circuit, each of said common registering devices including a plurality of relays selectively operable in various combinations, means to position said individual registering device, and means to transfer the registration thus accomplished to said common registering relays by the completion of simultaneous circuits.

10. In a telephone exchange system, an automatic switch, a registering device in dividual to said automatic switch, a plurality of equivalent registering devices, means to render said equivalent registering devices commonly available to said automatic switch, means to position said individual registering device, means to transfer the registration thus accomplished to a common registering device, and means to position said automatic switch under the control of said common registering device.

11. In a telephone exchange system, an automatic switch, a registering device individual to said automatic switch, a plurality of sending devices commonly available to said automatic switch, each of said sending devices comprising a series of registering devices, the first of said series being equivalent to said individual registering de vice, means to simultaneously position said individual registering device and associate an idle sender with said automatic switch, means to transfer an accomplished registration from said individual registering device to the first registering device of the series associated with the selected sender, means to position the remaining registers of the series, and means to selectively operate said automatic: switch in accordance with the positions assumed by said series of registering devices.

12. In a telephone exchange system, a link circuit, a registering device individual to said link circuit, a plurality of registering devices common'to said link circuit, means to associate one of said common devices with said link circuit, means to operate said individual registering device prior to the association of one of said common devices, and means to thereafter transfer the registration from said individual device to one of said common devices.

13. In a telephone exchange system, an impulse sender, a plurality of link circuits, a registering device common thereto, automatic switching means controlled by said registering device, and means for registering an impulse from said sender if said common registering device is not then available and for later transferring the registration to said common sender when available.

In witness whereof, I hereunto subscribe my name this 3rd day of January, A. D.,

WILLIAM H. MATTHIES.