US1161837A - Switch for automatic telephone systems. - Google Patents

Description

w, M. BRUCE. n. SWITCH FOR AUTOMATIC TELEPHONE SYSTEMS.

APPLICATION FILED JAN.26. 1912.

I Patented Nov. 30, 1915.

5 SHEETSSHEET l.

w. M. BRUCE, In. swncn FOR AUTOMATIC TELEPHONE SYSTEMS.

APPLICATION FILED .IAN.26,' I912- Patented Nov. 30, 1915.

5 SHEETSSHEET 2.

Hun. "'P w n Ila COLUMBIA PLANOORAPH co.,\vAsmNa'raN. D. C.

w. M. BRUCE, 1R.

SWITCH FOR AUTOMATIC TELEPHONE SYSTEMS.

APPLICATION FILED JAN.26. 1912.

Y Patented Nov. 30, 1915.

5 SHEETS-SHEET 3.

COLUMBIA PLANOORAPH CO-,WASHXNGTON. D. c.

W. M. BRUCE, JR.

SWITCH FOR AUTOMATIC TELEPHONE SYSTEMS.

APPLICATION FILED JAN-26. 1912.

1,161,837. Patented Nov. 30, 1915.

5 SHEETS-SHEET 4- a Q a a 0 a7 51 b O 38 a Z7 4 Q a T1 1 z: z, z i

,Z l I l 1 T 1 *;1. I 1 k a.

COLUMBIA PLANOURAPF 1 DDDDDDDDDDDDDDDD c.

UNITED STATES PATENT OFFICE.

WILLIAM M BR UCE, JR. OF SPRINGFIELD, OHIO, LASSIGNOR TO THE INTERNATIONAL AUTOMATIC TELEPHONE COMPANY, OF SPRINGFIELD, OHIO, A CORPORATION OF OHIO. I

SWITCH FOR AUTOMATIC TELEPHONE SYSTEMS.

Application filed January 26, 1912.

To all whom it may concern:

Be it known that I, \VILLIAM M. BRUCE, Jr., a citizen of tlie United States, residing at Springfield, in the county of Clark and State of Ohio, have invented certain new and useful Improvements in Switches for- Automatic Telephone-Systems, of which the following is a specification.

My invention relates to improvements in automatic telephony and especially to the construction and arrangement of the automatic switches and the circuits for the same, to effect interconnection between subscribers at an exchange without the use of operators.

This device relates particularly to the form of switch described in my co-pending application Ser. No. 6238, 192, in which a single movement or flat switch, such as usedv in the so-called Lattig & Goodrum system, as installed at Urban'a, OlllOfltIId elsewhere, is made to operate 11160111196131011 with d] iferent banks of contacts, sons. to extend itsoperation to a large number of subscribers, or to provide a larger; number of terminal, connections in each switch. r

This invention has also special relation to switches of the selector or connector type which are operated by impulses from a subscribers station connected thereto either directly or through the instrumentality of other so-called selector or finder switches. In the ordinary single movement or fiat switch, such asused by Lattig & Goodrum, wipers were arranged to bemoved step by step over aseries of fifty contacts or terminals andthe switch was adapted to serve fifty subscribers or trunks. In the present switch I have doubled the capacity by employing two groups of fifty so that a hundred line or trunk connections are provided for in two different banks. This is typical only, however, as the same arrangement might be made to apply to a larger number of banks and a fewer number of contacts in each bank, the preference bein to provide for one hundred lines or terminal contacts in each switch without the necessity of a vertical as well as'rotary movement, the only movement in this switch being a rotary one the respective wipers moving at all times in the same plane.

In the accompanying drawings: Figure 1 is a diagrammatic view showing the circuits which are preferably used for operating the Specification of Letters Patent.

Patented Nov. 30, 1915.

Serial No. 673,527.

switch of my improved construction. Figs. and are similar diagrammatic views showing some of the circuits only, other cir cuits being omitted for the purpose of clearness. Fig. at is a plan view showing the mechanical construction of a switch embodying features of my invention and applicable to the system herein set forth. Fig. 5 is a plan view of'the contact banks. Fig. 6 is an elevation of the same.' Fig. 7 is a diagrammatic view of these terminal contacts showing the relative arrangement in the different banks.

In the switch, which I have illustrated, the respective wipers which contact with the terminals in the banks, move in the same plane, and are arranged to move step by step over these bank terminals, but for the purpose of operating the switch in the decimal system, I provide for two sets of steps, towit: a long step and a short step and in the particular case illustrated the long step is made to move the switch wipers over five terminals or. contacts while the short step moves the wipers over a single contact. To do this two motor magnets are provided, one for the long step and one for the short step and means are provided by which the first or long step magnet is always operated at least one step before the second magnet is operated. 7

Means are also provided by which each set of the switch wipers which engage the clifferent bank contacts are either in or out of electrical circuit with the other mechanism depending upon whether the bank contact to be selected is in one bank or the other. In the present illustration, which embodies two banks of fifty lines each as'before stated, I

have arranged so that the first bank, say of fifty lines, has cooperating wipers which are normally in electrical connection with other necessary circuits and mechanism, and the wipers which serve the second bank of fifty lines are electrically disconnected. from the said circuits and mechanism, means being provided by which, when the line or terminal in the" second bank is to be served or connected, the first set of wipers is electrically disconnected and the second set electrically connected to the said circuits and mechanism.

Referring to Fig. 4 of the drawings, 1 represents the No. 1 or long step motor magnet Cir and 2 represents the No. 2 or short step motor magnet, 3 the release magnet, l is the bank of terminal contacts and 5 the shaft which carries the wipers which are adapted to pass over said contacts. l his shaft 5 is provided in tie usual way with a spring which holds it in the back or nor mal position and which is adapted to be put under tension as the shaft is revolved step by step and when released to return the shaft to its normal position. The general form of the switch is the same as has been heretofore used and a brief description of its working together with the special fea tures which I have provided will probably be sufficient for understanding it.

The shaft 5 is provided with two ratchet wheels A and The smaller ratchet wheel A having a series of ten teeth and the larger wheel 3 having preferably a series of fifty-five teeth. Th small ratchet wheel A is adapted to be engaged by a normally disconnected pawl (t pivoted to a lever (L2 and provided with an extension or tail piece a which normally contacts with a stop on the switch frame to hold the pawl al out of engagement. The lever a is connected to or is a part of the armature (6 of the No. 1 motor magnet and a s iring a is provided which when the magnet is deenergised retracts the same, moves the lever a to its rearward position and by causing the tail piece a to engage the stop forces the pawl 64 out of engagement with the ratchet teeth of the ratchetwheel A. The lever a? is also provided with an extension (1, which carries pawl tooth at, which, as the lever is moved forward and reaches the limit to its forward stroke, engages a tooth of a reverse ratchet a formed on the wheel A and thus stops the said wheel and prevents it from overthrowing. This forward movement of the lever (4 under the influence of the magnet, also permits the pawl (1?, by means of a spring a7, to be forced into engagement with the teeth of the forward ratchet a and move it one notch which is suliicient to advance the wipers carried by the shaft 5 over five contacts, except in the first instance, in which case, the relative position of the pawl (4- and the first tooth of the ratchet is such that the wipers are advanced only one step onto what call the Zero contact.

The ratchet wheel is adapted to be engaged by a pawl b on a spring pawl carrying arm 5 pivoted to the lever 7% on the armature Z) of the motor magnet 2 which is also provided with a spring F2 for retracting the arinatiilre when it is deenergized. In this case I have preferably arranged the pawl b to move over one notch in the ratchet wheel B when the magnet is energized and to move back to its normal position, and thus advance the Wheel one step, through the agency of the spring Z) when the magnet is deoncrgized, being in this case a reversal of the action of the magnet 1 which advances the ratchet wheel when the magnet is energized and is returned by the spring when deenergized, either arrangement, however, can be used as preferable in either of the magnets, it being not an essential feature of the invention whether the magnets advance the ratchet wheels when energized or when they are decnergized.

The ratchet wheel vanced position by a sprin engages the ratchet wheel at cept when it is withdrawn by the l magnet 3 whose armature L is 3-0 with extensions 6 and b which are adapted to engage with the spring pawl pivoted lever Z2 when the release magnet 3 is energized and thus withdraw both of these pawls from the ratchet wheel to permit the said wheel, and the spring actuated shaft to return to normal position.

I have stated that the switch prefei ably )rovided with fifty sets of contacts arranged in two banks, It will be noticed, however, that I have illustrated the bank as having fifty-seven contacts but this due to the fact that the terminal constituting the second or lower bank are advanced five contacts ahead of the contacts in the first or upper bank and that the first contact is a. normal or Zero contact. This will appear more clearly hereinafter. liac i of the banks contain three sets of terninals and there is an additional or seventh set which might be termed the switching terminals and through which the connections between the wipers of the first and second banks are connected and disconnected. This permits these banks to be divided up into groups of ten while the No. 1 motor magnet advances the wipers over five contacts only at a time, the first groups of ten in the upper bank starting with the second contact of the series and the first group of ten in the lower bank starting with the first contact of the lower bank which is innne diately under the sixth contact, of the upper bank.

It will be obvious from the further descr'ption that the first five contacts in the lower bank and the last five contacts in the upper bank might be dispensed with as they have no connections, they are only shown for symmetry in the making of tee switch. It will also appear from the further description that the lower or seventh row of terminals in the banks need not necessarily be in the banks, but might be placed at any point on the switch frame with a wiper to properly engage the same when the shaft is moved and that the number of contacts could be reduced to ten as only T 7 ii" ten of these contacts perform active functions.

In Fig. 1, I have shown a diagram of the circuits and apparatus for operating the switch. These circuits are in many respects similar to the usual circuits used for operating a connector switch in the Lattig & Goodrum system except as they are modified to suit and to meet the requirements of the improved features which I have added thereto and in general they embody the combination of quick and slow relays which are adapted to respond to impulses transmitted from the subscribers station so as to first operate on the motor magnet No. 1 and give the switch the necessary long step after which by the aid of auxiliary switch mechanism the circuits are transferred to the motor magnet No. 2 and a series of short steps are given the circuits of both of the magnets being afterward opened when the switch is properly positioned with means also for shifting the circuits of the switch wipers so that only those wipers operating in'connection with the bank in which the particular terminals to be selected are located will be in circuit.

In Fig. 1, MM represents the long step motor magnet and MM the short step motor magnet. A is the operating relay preferably having a double winding and B and C are slow relays which are adapted to be energized by the operation of the relay A and. to close and hold closed certain circuits and open and hold open certain other circuits during the time that the switch is being positioned. D is the ringing relay which is also operated through relay C from the operating relay A and is held energized so long as the impulses are passing through. The various relays and magnets are shown for the most part connected on one side to ground or to grounded battery and the wires marked 9 indicate the ground connection and the wires marked by indicate connection to the grounded battery. The relay A has its respective windings connected to the respective sides of the main line or talking circuit a and a which comes into the oonnector switch from the subscribers station through the preceding switches. The other ends of the respective windings are connected to the wires 9 and by and thus to the opposite sides of the battery B, so that as soon as connection is made from a preceding switch to the connector switch, the operating relay A is energized, assuming the line to be closed at the subscribers line in the usual. way, the circuit passing through the ground by wire 9, so that ground is thus removed from contact 2 and placed on contact 3. Contact 3 is connected by wire 1 to branch connection 5 from thence it leads through wire 6 to relay B and thence by wire 69 to battery so that the energizing of relay A also energizes relay B. From the connecting point 5, wire 7 leads to front contact 8 on relay C while armature spring 9 immediately above said contact is con nected by wire 10 to relay D which is also connected by wire 59 to battery and ground. This circuit of relay D is normally open at contact 8. The back contact 2 of the operating relay A is connected by wire 11 to armature spring 12 of the relay B, which normally engages back contact 1.3. lVhen relay B is energized, however, this armw ture 12 engages contact 1st which is connected by wire 15, wire connection 16 and wire 17 to relay C which is connected by wire by to battery and ground, so that in case the operating relay A is deenergized and its armature moves against contact 2, the relay 0 would be energized over the circuit just traced providing the relay B remains energized to retain the circuit closed at contact 14. From connecting point 16 a branch 18 leads through back contact 19, armature spring 20 and wire 21 to a switch arm '22 of an auxiliary switch J. This switch arm in its normal or first position engages contact 23 which is connected by wire 24, wire connection 25 and wire '26 to MM thence by line by to battery and ground, so that the closing of the circuit between armature 1 and contact 2 which will energize the relay 0, will also energize the motor magnet MM providing the circuit last described is closed at contact 19 and the auxiliary switch J is in its first position. Assuming the operating magnet A to have been energized by the line wires being connected to the connector switch and this is followed immediately by the energization of the relay B, if the line is momentarily broken relay A, in dropping back, would energize the slow relay C and the motor magnet MM and if the line should be immediately closed giving an impulse, the operating relay would vibrate and retain relay B energized and deenergize the motor magnet MM and cause it to take one step. In case a series of impulses fol-- lowed in fairly rapid succession the slow relays C and B would both be held up while the motor magnet MM would be operated so as to vibrate its armature in unison with the operatin relay A. This will cause the motor magnet MM to make as many steps as there are vibrations and cause it to select the particular group of ten in which the subscriber to be called is located. In Fig. 2 I have shown circuits directly involved in this particular part of the system with some of the other features eliminated. In this figure S represents a subscribers station S S and S represents finder and selector switches through which the connection made to the connector switch and to the operatin relay A.

As before stated the first movement of the motor magnet MM moves the wipers only on the zero contact, the second movement to the liith contact, the third to the contact etc, also, as before stated, the contacts in the lower set or bank are moved live contacts ahead of those in the upper bank so tha contact N0. 50 is directly under N0. I provide in the set of wipers a supplemental wiper which traverses the lower row of terminal contacts in the bank, which contacts other than those immedia ely under terminals perform no icular con- These p contacts represent an even. number of steps of he first motor magnet so that in the event that the wiper 2'2 should stop on the second. fourth, sixth, etc, step this supplemental be gr uinded. From the wiper 2i, wire 1 eads to a switch arm 29 on the auxiliary switch and this switch arm normally engages contact 30 connected by wire 31 to armature 32 (of relay which is adapted to engage the contact 33. which is connected by wires 34: and 35 to relay 3' thence to bi ttery and ground so that in the event that the wiper 27 stops on a grounded contact and the circuit of relay G is closed at contact 323 then relay G will be energized.

wiper 2? would lhe circuit for relay may be traced from ground at the oil-normal switc i 3G. by contact 37, wires and 35), through various contacts shown on Fig. 1 but omitted in Fig. to contact l0, armature on relay (7, wire :2. to relay E, battery and ground. The contact 4& is a bael: contact so that the circuit for relay l is closed when the rea v C is dei nrp ized and when the relay (1 is energized this circuit is open, the result being that the relay G can we energized only at such time as the relay is energized and the relay C is deiinen The relay is ener d. as before I when relay it. is momentarily deized allowing cont; cts 1 anc 2 to close relay A with ti 0 slow relay B holding p its arn'iature and relay 0 will remain neigized as long as impulses are passing through A owing; to the vibration of the of relay E which in turn closes the circuit of relay (l as betore described. and in the event that the supplementary wiper 27 is resting on a gr unded contact and not otherwise the relay G would be operate Relay (It controls armatures and L3 which normally engage back contacts and. in the circuits of the upper bank of wipers out are adapted when moved to their other posi tion to engage contacts 46 and i? in the circuits of the lower groups of wipers. these armatures themselves being connected by wires L8 and :9 to contacts 50 and 51 in the auxiliary svitch 5.

Relay G is provided with a locking circuit which may be traced over wires 35, 52, contact armature 5i on said relay it wire to wire contact 37 and grounded at otlnormal switch 36, so that whenever the relay cl is energized over the circuit, above described including- .riper 27, it will be held energized over the last descri bed circuit even though the wiper 27 be moved of a grounded contact or the circuit from said wiper to the relay 1:? be broken at the auxlileans are thus provided iliary switch J. by which, whenever the auxiliary wiper 27, at the end of a series of impulses st ps on a grounded contact. relay (t will be energized and the circuits from the wipers relating to the upper bank vill be opened and the circuits to the lower bank will be clo e; The relay E in addition to operating the armature above described also operates the eccapement for the auxiliary switch and at each operation permits the arms of the any iliary swit J to move to a different position, there being}; in this case preferably three positions which this switch may occupy. As soon therefore as the first set of impulses have ceased, the auxiliary switch element vill be transferred from the first to the second position and switch arm 2 leaves contact and stops on contact 23" which is conncc No. 2 (Ms thence to battery and ground so that after the first movement or the switch J, motor magnet No. l is cut out and motor magnet l lo. 2 is cut into the circuit with the operating relay it and the slow relays B and C as before described. Switch arm 29 has also passed oil of contact 30 thus opening: the circuit from wiper 2? to relay G and preventing relay {1} from being ener- :ed by any subsequent move of the wiper in case it has not been energized at the end ot the first series of impulses and if it has been so energized it will remain energized as before described over the locking circuit 52, 5d and 55 after the switch arn'i 29 moves or? ot the contact 30. If another series of impulses are now sent from the subscribers station the operating relay A will be operated as before and cause motor magnet No. 2 to be vibrated which in turn d by wire 2% to motor magnet lit will give the main switch wipers as many steps as there are impulses. In this case, however, the steps will be short steps over one contact instead of over five contacts at each step and the individual contact in the particular group of ten desired will be selected.

Suppose now it were desired to select terminal No. 5, this number being tin the first group of ten the impulse transmitted would be operated to give one impulse, this could cause one step only of the motor magnet No. l which, as before described, would merely be a preliminary step on the zero contact being, however, sufficient to close the off-normal switch contact at 37, at the end of this impulse the slow relay C would be deenergized which would close the circuit of relay E, the energizing of relay E would also close the circuit for relay G at contact 33 but inasmuch as wiper 27 has not stopped on a grounded contact the relay G would not be energized and the switch wipers for the upper bank would remain in circuit and those of the lower bank would be out of circuit. The energizing of relay E would cause the switch J to make one step which would thus open the circuit of relay G at contact 30 and also open the circuit of motor magnet No. 1 at contact 23 and switch motor magnet No. 2 into circuit with the operating relay A and the slow relays B and C as before described. The operator now sets his impulse transmitted to make five impulses and the wipers are caused to make five steps, bringing the series of wipers to rest on'the fifth terminals in the banks, the wiper 27 will now rest on a grounded contact but inasmuch as the circuit from this wiper is open at contact 30 the relay G is unaffected and connection is made with the fifth contacts. The energizing of the slow relay C has opened the circuit for relay E at contact 40 and it is then in position to produce the second step of the auxiliary switch J and as soon as the second series of impulses cease the slow relay C, upon being decnergized will again close the circuit for relay E and cause the auxiliary switch J to take another step and thus move its arms to the third position, and this will cause the switch arms 56 and 57 to move onto the contacts 50 and 51 which are connected with the armature springs 42 and 43 and through these springs and contacts M and 45 by wires 58 and 59 to the switch wipers 60 and 61 of the upper bank. The auxiliary switch arms 56 and 57 are connected by wires 62 and 63 to what I term theanswering relay A wires 62 and 63 are also connected by wires 64: and 65 and condensers 66 and 67, wires 68 and 69 to the main wires or and a, so that the talking circuit is established directly through the condensers and the circuit above described including the auxiliary switch arms 56 and 57 to the wipers 60 and 61 thence through the bank terminals to the called subscriber who may then be signaled in the usual way. Battery for talking purposes is fed to the calling end of the line through operating relay A and to the called end of the line through answering relay A In the event that the subscriber 51 was desired the first movement of the impulse transmitter would be to transmit two impulses. This would cause the main switch wiper at the first impulse to move one step on the zero contact and the second impulse to move one long step, that is over five contacts stopping on the fifth terminal. This being an even number of steps the wiper 27 will at the end of the first series of steps stop on a grounded contact and as the impulses cease the relay Cwill be deener ized and close the circuit for the relay E which will in turn close the circuit for relay Gr and thus switch the circuit from the upper bank of wipers to the lower bank. Energizing the relay E will also cause the auxiliary switch to move one step, as before described, which will switch the operating circuit from the motor magnet No. 1 to motor magnet No. 2 and also open the circuit from the auxiliary wiper 27 while the relay G is held up by the locking circuit so that any further movement of the wiper will not influence this connection. The subscriber now makes one impulse over the lines which causes the wipers to advance one step thus 1 contacting with the sixth terminal which corresponds to 51 in the lower bank and inasmuch as the lower bank wipers are in circuit and the upper bank wipers and circuits are open the connection is made with the No. 51. It will be understood that this arrangement of numbering is merely arbitrary, that is, I have considered all the numbers from 1 to 50 to be in the upper bank and those from 51 to 100 to be in the lower bank. The lower bank contacts being advanced five numbers ahead of the upper bank, so that 51 rests under the 6th contact, 60 under the fifteenth, etc., then under this arrangement whenever an even number ofimpulses is sent at the first call it selects a number in the lower bank while an odd number of impulses at the first call selects a number in the upper bank. It is obvious that inasmuch as this numbering is merely 12o arbitrary the first ten might be arranged in the upper bank and the next ten in the lower bank, etc. In this case the odd multiples of ten would appear in the upper bank and the even multiples of ten in the lower bank. This involves a little more complication in the wiring of the bank and the other system of having the first fifty in the upper bank and the next fifty in the lower bank requires an arbitrary 13o adjustment or arrangement of the subscribers numbers.

It will be seen from the above that two movements of the dial or calling device are necessary to select any number in the connector switch, the first operates the No. 1 or long step motor magnet and the second 0peratcs the No. or short step motor magnet. The first movement or set of impulses selects the particular group of ten in which the unit appears and the second movement selects the particular unit in that group of ten. If the group of ten to be selected requires an odd number of impulses of the No. 1 motor magnet, the numeral to be selected will be in the upper bank if the group of ten requires an even number of impulses of the first or long step motor magnet then the numeral will be in the lower bank.

It also follows that numerals representing even multiples of ten will be selected by ten steps of the No. 2 motor magnet and not by any number of steps of the No. 1 motor magnet, so that in selecting the numeral ten the first motor magnet would receive one impulse and the second motor magnet ten impulses. In selecting the numeral 50 the first motor magnet would receive nine im pulses which would land it on the fortieth contact, and the second motor magnet would receive ten impulses which would land it on the fiftieth contact. In selecting the terminal 60 the No. 1 motor magnet would receive two impulses landing it on the fifth contact, but this being a grounded station it becomes a lower bank connection by reason of the lower bank wipers being brought into circuit and if followed by ten impulses of the No. motor magnet stops on the fifteenth terminal or its equivalent GO in the lower bank. The same way the selection of the seventieth would require four steps of he No. 1 motor magnet which would take it to the fifteenth contact, but this station being grounded it becomes a lower bank selection and would be equivalent to the sixtieth terminal then this followed by ten steps on the N0. 2 motor magnet would move the wipers to the twentyfth terminal, whose equivalent in the lower bank would be terminal No. 70. The same way in selecting the one hundredth terminal, ten impulses on the No. 1 motor magnet would land on the forty-fifth terminal whose equivalent is 90 in the lower bank. this being a grounded station, the ten impulses on the No. 2 motor magnet would select the one hundredth contact in the banks.

In the above description I have included the essential features of my improved switch and its operation. In addition to these, the switch embodies the usual operating release and busy circuits, a form of which is shown in Fig. 1. Many of these circuits are also shown in Fig. 3 and omit ted in Fig. 2. Some of these circuits will now be described.

I have already referred to the ringing relay D which is energized by closing the contacts 8 and 9 whenever the slow relay C is energized. This ringing relay D controls armature springs 70, 71 and 72. The spring and its back contact 70 is included in the circuit 62 which is connected through auxiliary switch arm 56, contact 50, wire 4L8 and armature spring 42 to the wipers (such as 60 and G1) which select the called subscribers terminals so that it is thus connected directly to the selected subscriber. Contact 70 is in the generator circuit so that when the ringing relay 1) is operated after the auxiliary switch has moved to its third or last position, ringing current will be applied to the called line. Armature spring 71 is connected to ground ti aigh wires 38 and 39 and the off-normal switch and thus in the circuit of the auxiliary switch relay E. Contact 71 is connected to wire 63, so that when the ringing relay D is operated the circuit for the relay E is opened and ground is placed on the other side of the called subscribers line thus completing a ringing circuit to the called subscriber. After the switch has been operated to select any terminal, the auxiliary switch is in its last position, both motor magnets will be cut out and any movement of the calling device, which will cause a series of impulses to pass over the line, will operate slow relay C and the ringing relay D, and thus cause ringing current to be applied to the called line so long as the impulses are passing; in this way, ringing current will be applied by operating any number on the calling device, a short series of impulses giving a short ring and a long series of impulses giving a long ring.

We will. next consider the busy test and relay H, which is the busy relay. In each group of wipers, that is, the group for the upper bank of contacts and that for the lower bank of contacts, there is a test wiper 73 and 73, which is adapted to traverse a series of conta ts which are connected in multiple to the difi erent switches in a group in the usual way. lhese test wipers 73, 7 3 are connected by wires 74 and 74: to back and front cont- act 75 and 75 on each side of armature spring 7 o of relay G from said armature spring wire '7'? leads to auxiliary switch arm 8 which in its last or third position rests on a grounded contact 80, so that when a line is selected ground is placed on the test contact corresponding to this line thus rendering this line busy to any other call coming in over a multiple of this line. In the second position oi the auxiliary switch, switch arm 78 will rest on contact 79 which is connected by wire 81 to contact 72 on the ringing relay D. Armature spring 72 of this relay is connected through wire 82, spring 83 (of relay C), contact 84:, wire to the busy relay H and to battery and ground so that if the line selected should be busy, wiper 73 would fall on a grounded contact and busy relay H would be energized o er the circuit just described, that is, from grounded wiper 73, wire 74:, contact 75, spring 76, wire 77, auxiliary switch arm 78, contact 79, wire 81, contact 72 spring 72, wire 82, spring 83, contact 84, wire 85, relay H, battery and ground. This circuit would be held open at contact Sat so long as the relay C was energized and it would be open at contact 72 unless the relay D were energized, but relay 0 is de energized after each set of impulses and relay D is deenergized when relay C has reeased its armature spring Both of these relays being slow relays and being held up while the series of impulses are passing through, so that in case the test wiper 78 should stop on a grounded contact after the first set of impulses, relay C would be deenergized and close the circuit for the busy relay H before the relay D had time to drop back and open the circuit for relay H at contact 72. Relay H carries an armature spring 86, which is normally in circuit from wires 38 and 39 which is a part of the circuit of this auxiliary switch relay E, the armature spring 71 on the relay D is also a part of this circuit for relay E being located between wires 39 and 89 as shown in Fig. 3, so that this circuit is held open so long as either relay 0, D or H is energized. Since relay H becomes energized before relay D is deenergized the circuit of relay E can not be closed in case the relay H is energized by the test wiper 73 stopping on a grounded contact and hence the auxiliary switch will. not pass to its third position.

lVhen spring 86 is moved away from this back contact so as to break the circuit of relay IE it engages a front contact 86 connected by wire 86* to wire 85 so that the relay H is locked up by the circuit from grounded battery, wire 85, wire 86 contact 86, spring 86 wires 38 and 38, contact 37, oil-normal switch arm 36 to ground. Relay H also carries an armature spring 87 adapted to engage front contact 88 which is connected by wire 89 to contact 90 in the second position of the auxiliary switch arm 57 which as before described and as shown in Fig. 2 is connected through wires 63 and 65 and through the condenser 67, wire 69 to the calling side of the line, thence back through the calling subscribefls telephone, line wire a, wire 68, condenser 66. wire 64;, winding of coil A wire by, through battery B to ground. This armature 87 is connected to the busy tone so that when armature spring 87 is pulled up by the relay H a busy signal is sent to the calling subscriber. It

will be observed that the circuit for the motor magnet also passes through armature 20 on the busy relay H and hence w ien said relay is energized this motor magnet circuit will be broken at contact 19 (see Fig. 1) and further operation of the motor magnet would be prevented by the impulse transmitter and the operation of said transmitter by the calling operator would result only in again impressing the busy tone upon his line by energizing the relay D who thereupon hangs up and releases the switch.

The release of the switch is accomplished by opening the circuits of the respective parties at their respective stations by hanging up their receivers. of the connector switch is indicated by R and the back release for the other switch is made over the release trunk (612. The circuit for the release magnet B may be traced as follows: from ground through armature 1 of the operating relay A, back contact 2, wire 11, armature 12, slow relay l3, back contact 13, wire 91, spring 92, contact 9-3, (on answering relay A wire 9%, contact 95, off-normal spring 96, wire 97, release relay R, battery and ground, so that the release circuit will be closed whenever the relays A, A and B are ceenergiaed and this will occur when the called and calling subscribers hang up their respective receivers and thus open the respective line circuits for the called and calling subscriber. From wire 97 a branch 98 leads to a relay R to battery and ground. This is the release relay for the auxiliary switch J so that the auxiliary switch J is released at the same time.

The back release for the other switches may be traced from trunk a, spring 99,

contact 100, wire 101, spring 102, contact 1 103, to wire 91, so that the circuit for the preceding switches will be closed to ground at the same time by the de'e'nergization of the relays A, A and C. The slow relay C has a back contact 105, for its armature spring 99, which is connected to trunk release a, this back contact is connected by wire 106 to spring 107 and grounded contact 108 on the slow relay B so that in the event that the calling subscriber should hang up before the call is completed and before the called subscriber hangs up, the dropping back of armature 1 would not release the connector switch owing to the release circuit being held open at contact 93 of answering relay A It would energize relay C, in the manner before described, this would be followed by the de'e'nergizing of relay l which will permit armature spring 107 to drop back onto grounded contact 108 and thus ground the trunk release through wire 106, contact 105, and spring 99 and release the preceding switches and thus freeing the calling subscriber from the connec tion, the connector switch would be re- The release magnet U eased when the called subscriber hangs up hus closing the release circuit at 93 over the circuit heretofore described. I have provided the relay with armature springs 109 and 114. Spring lll is for supervisory purposes and is connected to a supervisory wire and when in contact with 115, which is in a branch from wire in the No. 1 motor magnet circuit shows when the switch has been operated. Spring 109 is connected to ground from and is adapted to be brought into and held in engagement with contact 110 whenever relay E is energized and until the ainziliary itch J is released by relay magnet R This puts ground onto the contact 113 over wire 112 so that in the event that the auxiliary switch had not been completely released when the main switch returns to normal, the off-normal spring 96 engaging with contact 113 will again ground the release circuit for lease relay B and cause the auxiliary SIlLCll to be completely y oi sets of wipers one for each bank, the contacts in each of said banks being arranged in groups, means for moving said wipers to the diticrent groups, the groups ct one bank bein advanced in their relation to groups in the other banks, and 112651115 connected with the said banks to cause the wipers pertaining to the said banks to be elec rically connected or disconnected as they are mored to a group in one bank or the o her bank.

In a connector switch, a series of groups of terminals arranged in a plurality of @IS, and a plurality of wipers to engage the terminals in each bank, the groups of contacts in one bank being relatively advanced eve the groups contacts in the other bank, separate means for advancing said wipers steps to seby long and SllOl'b lect a group and a contact in the group, and means connected with the respect-ire groups to cause the wipers to be electrically connected disconnected when moved into a group pertaining to the group to be seiected.

3. In a switching apparatus for automatic exchanges having a plurality of terminal banks and a plurality of sets of wipers one for each bank, means for opera ing both sets oi wipers simultaneously by long and shortsteps to cause them to engage terminals in the respcctire banks, a separate contacting device moving with said wipers to engage contacts when moved by said long steps, and means operated through said auxiliary contacting device to cause one set of wipers to be electrically disconnected and the other set of wipers to be electrically connected.

a. In a switching mechanism for automatic telephone exchanges, a plurality of sets of bank contacts and a plurality of sets of wipers, electrical connections from each set of wipers to a switching deyice, a single set of connections from said switching de vice, and a separate contacting device moving with said wipers to cause said auxiliary switching device under predetermined conditions to connect with one set of wipers and be disconnected from the other for the purpose specified.

In an automatic telephone exchange, a switch having a plurality of terminal be ks and a plurality of sets of wipers, one set for each bank, means for operating said wipers to cause them to simultaneously engage terminals in the respective banks, electrical connections from said wipers, a switching relay adapted to close one set of said connections and open the other, and means connected with said wipers for energizin said relay at a predetermined movement of said wipers.

6. In an automatic switch, a series of wipers adapted to simultaue usly engage terminals in different banks, electrical connections from said wipers, and a switching relay for opening the electrical connections of some of said wipers and closing the connections to others, and a contacting device moving with said wipers, and means for operating said relay from said contacting de vice at certain predetermined movements of said wipers.

7. In a switch having a plurality of sets of wipers adapted to engage sinniltaneously different terminals arranged in dillerent banks, the terminals of one bank being relatively advanced over the terminals of the other bank, means for advancing said wipers by successive sets of steps, one set comprising long steps and the other set comprising short steps, electrical connections from said wipers to said switching relay, and means for operating said relay at the termination of a certain number of predetermined long steps.

8. In an automatically operated switch having different sets of terminal contacts arranged in different banks and a set of wipers for each bank, motor magnets for operating said wipers, one to produce long steps and the other to produce short steps of said wipers, means for successively switching said motor magnet into circuit to operate said switch, electrical connections from said wipers to the switchingrelay, and means for operating said switch and relay to close one set of wipers and open the other set at the conclusion of the ooeration of the long step motor magnet and means for preventing a further operation 01 said relay after the second or short step magnet has been operated.

In a switch having a. plurality of sets of wipers adapted to engage simultaneously different terminals arranged in different banks, electrical connections from said wipers, and a switching relay for opening the electrical connection from some of said wipers and closing the connection to others, a contacting device moving with said wipers, means for operating said relay from said contacting device at certain predetermined movements of said wipers, and means for preventing a subsequent operation of said switching relay by a further or subsequent operation of said contacting device and before the switch is returned to normal or zero position.

10. In a switch having a plurality of wipers in sets adapted to be moved simultaneously to engage difierent contacts, a separate contacting device moving with said wipers, a switching relay adapted to open the electrical connection with some of said wipers and closing it to others, means for operating said relay from said contacting device, means for advancing said wipers by successive sets of steps, one comprising long steps and the other short steps, means for operating said relay when the contacting device rests on a certain contact at the end of a predetermined number of long steps for preventing the operation of said relay when the contacting device should engage the same contact when being moved by the set of short steps.

11. In a switch having two banks of fifty contacts each, the contacts in one bank being advanced five spaces over the contacts of the other bank, wipers for said banks and two motor magnets, one adapted to advance said wipers by long steps and the other by short steps, a switching device, electrical connections from said wipers to said switching device and a switching relay for opening the connections from one bank and closing the connections to the other, separate contacts spaced to correspond with the steps or multiples thereof of the long step magnet, a movable device moving with said wipers to engage these contacts, a connection from said device to the switching relay, and means for supplying current through said contacts to the switching relay when the same are engaged by said movable device after a predetermined movement of said long steps so as to switch the electrical connection from one set of wipers to the other as and for the purpose specified.

12. In a switch for automatic telephones, terminal contacts arranged in banks and wipers for each bank, a switching device, electrical connections with one set of wipers to said switching device, means for operating said switching device to disconnect some of said wipers and connect other wipers, a switching relay for operating said switching device and a circuit for said relay including a circuit closer operating simultaneously with said wipers, means for moving said wipers successively by long and short steps, and means for operating said circuit closer to energize said switching relay at the termination of a predetermined number of long steps and preventing its operation when the wipers are moved by short steps.

13. In an automatic telephone exchange, having a plurality of terminal banks and a plurality of wipers, one set for each bank, means for operating the wipers to cause them to engage the terminals in the respective banks, and means for connecting one set of wipers and disconnecting the other set at predetermined positions of said wipers and means for releasing said switch to permit said wipers to return to normal as and for the purpose specified.

l l. In an automatic telephone exchange having a plurality of terminal banks and a plurality of wipers arranged in sets, one set for each bank, means for operating said wipers to cause them to operate the terminals of the respective banks consisting of motor magnets, one of which advances the wipers with a long step and the other with a short step, the terminals in one bank being advanced over the terminals of the other bank a distance equal to one step of the long-step motor magnet, and means at certain steps of said long-step motor magnet to establish an electrical connection and through said connection to disconnect one of said wipers and connect the other, as and for the purpose specified.

In testimony whereof, I have hereunto set my hand this 20th day of January 1912.

WILLIAM M. BRUCE, JR.

Witnesses:

CHAS. I. WELCH, ESTHER E. PFEIFER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C.

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