US1193137A

US1193137A - Call-registering system for automatic telephone systems

Info

Publication number: US1193137A
Authority: US
Publication date: 1916-08-01
Anticipated expiration: 1933-08-01

Description

C. L. GOODRUM.

CALL REGISTERING SYSTEM FOR AUTOMATIC TELEPHONE SYSTEMS.

APPLZCATION HLED APR. 24. l9l5.

Patented Aug. 1, 1916.

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VV/fnesses:

APPLICATION FILED APR. 24,1915.

Patented Aug. 1, 1916.

UNITED STATES PATENT OFFICE.

CHARLES L. GOODRUM, OF NEW YORK, N. Y., ASSIGNOR, BY MESNE ASSIGNMENTS, TO WESTERN ELECTRIC COMIPANY, INCORPORATED, A CORPORATION OF NEW YORK.

CALL-REGISTERING SYSTEM FOR AUTOMATIC TELEPHONE SYSTEMS.

Application filed April 24, 1915.

To all whom it may concern:

Be it known that I, CHARLES L. GooDRUM, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Call-Registering Systems for Automatic Telephone Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telephone exchange systems employing automatic line finderswitches for associating calling lines with idle connecting circuits. Its object is to provide an improved metering circuit arrangement for such systems.

In accordance with this invention the operating magnet of the meter of each line is connected to the multiple test contacts of such line in the automatic finder switches in which such line appears and is of low resistance, and the test circuits of the finders are of high resistance relative to that of the meter magnets. Vith this arrangement the meters are not operated during the testing operation of the finders, since the circuit conditions are such that their operating magnets will not receive enough current. When the calling line has been extended to a connecting circuit, however, and connection has been made with the wanted line, the response of the called party renders operative means for closing a circuit of suilicient strength to operate the calling line meter magnet. The meter magnet is provided with a locking winding so that upon its actuation it will remain locked up during the entire duration of the connection and thus prevent accidental operation of the meter. This locking winding may be included in parallel with the cut-off relay of the line and may be controlled at an off-normal contact of the finder.

Referring to the drawingsFigures 1 and 2 show a circuit arrangement embodying the invention.

The subscribers lines a b terminate as calling lines in

multiple contacts

137, 138 of a group of finders like that shown diagrammatically in Fig. 1, and as called lines in

multiple contacts

225, 226 of a group of connectors like that shown diagrammatically in Fig. The closure of the line circuit by the removal of the receiver from its switchhook by a calling party causes an idle line fi der to be set in motion to connect with Specification of Letters Patent.

Patented Aug. 1, 1916.

Serial No. 23,565.

such line. The finder then in a primary rotary movement, selects the group of terminals containing the calling line and in a secondary vertical movement the particular line in such group which is calling. The calling line is thus extended to the connec tor shown in Fig. 2 which is in turn caused to connect with the desired line by a primary and secondary movement under the control of the sender 157 of the calling party at substation A.

A general description of the mode of op eration having been given, it is thought the invention will be readily understood from a detailed description of the operation of interconnecting two substations.

The removal of the receiver 100 at sub station A causes the closure of the line circuit and the operation of the line relay 108. Relay 108 at its armature and front contact closes the circuit of relay 101 which is common to the group of subscribers to which substation A belongs. The relay 101 at its armature and front contact closes the following circuit for slow acting relay 105 to start the line finder in motion: free pole of battery, relay 105, conductors 102, 111, finder off-normal contact 103, now closed to conduetor 111, conductors 104, 109, armature and front contact of group relay 101, to ground. A circuit for the side-switch escapement magnet 107 in parallel with re lay 105 is also closed by relay 101 as follows: free pole of battery, left-hand winding of escapement magnet 107, conductors 110, 111, finder off-normal contact 103 to ground over the circuit just traced for relay 105. If the finder allotted to this group of lines is idle, a brush 115 carried by its wiper carrier or shaft (not shown) rests on a dead or home contact 116. In this posi tion a set of

wipers

128, 133, 136, 139 ca.r ried by the finder shaft is one step removed from operative relation to the group of line terminals containing those of substation A. It is therefore necessary to give the finder shaft one rotary step before it can hunt over the terminals in the group to which it is allotted.

Upon the closure of the front contact of slow relay 105, due to the energization of relay 101 as described, the following circuit is closed for the primary stepping magnet 118 of the line finder to give the finder this rotary step to pick out the group of lines containing calling substation A: free pole of battery, primary stepping magnet 118, armature and back contact thereof, conductor 119, side-switch arm 120 and its first contact, conductor 127, right-hand winding of escapement magnet 107, conductor 122, righthand armature and front contact of slowacting relay 105, conductor 123, conductor 200 (Fig. 2), left-hand armature and back contact of relay 201, conductor 202, righthand armature and back contact of relay 203, conductor 204, armature and back contact of relay 205 to ground. The primary stepping magnet 118 thereupon interrupts this circuit at its front contact and a pawl carried thereby (not shown), rotates the finder brush shaft one step, whereupon the group test brush 115 engages the segment 158 of the group containing substation A, from which ground was removed at the back contact of the group relay 101. Side-switch escapement magnet 107 releases the side or steering switch into its second position in the wellknown manner, due to the opening of offnormal contact 103. While the circuit of relay 105 is also opened when finder offnormal contact 103 opens, it is slow acting and before it can release its armatures the following circuit is closed through its right hand armature and front contact free pole of battery, conductor 125, secondary stepping magnet 106, its armature and back contact, conductor 126, side-switch arm 120 and its second contact, conductor 127, righthand winding of side-switch escapement magnet 1 07, conductor 122, right-hand armature and front contact of slow relay 105, conductor 123, conductor 200 to ground at the back contact of relay 205 over the circuit previously traced. The secondary stepping magnet 106, by means of a pawl (not shown) connected to its armature gives the shaft of the line finder a secondary vertical step due to the closure of this circuit, whereupon its

brushes

139, 136, 133, 128, engage with the first set of terminals of the group containing the

terminals

138, 137, 132, 129 of calling line A. Contact between brush 128 and test terminal 129 occurs beforethe armature of magnet 106 opens its back contact, this opening occurring near the end of its stroke. Escapement magnet 107 attracts its armature due to the closure of this circuit and locks itself up to ground at the armatures andback contacts of the line relays 108 of non-calling lines over the following circuit: freepole of battery left-hand high resistance winding of escapement magnet 107, armature and front contact of said magnet, conductor 112, side-switch arm 113 and its second contact, conductor 161, brush 128, terminals 129, low resistance right-hand windings of meter magnets 143, conductors 147, to ground at the armatures and back contacts of line relays 108. This circuit is closed before slow relay 105 releases. This relay is therefore maintained energized in parallel with escapement magnet 107. The secondary stepping magnet 106 now interrupts its circuit and causes the line finder brushes to wipe over the terminals of the calling group. This circuit is as follows: free poleof battery, a conductor 125, magnet 106, its armature and back contact, conductor 126, side-switch arm 120 and its second contact, conductor 127, right-hand winding of escapement magnet 107, conductor 122, right-hand armature and front Contact of slow relay 105, conductor 123 to ground at the back contact of relay 205 of the connector over the circuit previously traced. As soon as the calling line is reached, the escapement magnet 107 and slow relay 105 are deenergized, since no ground is present on the test terminal 129 thereof, due to the energization of the line relay 108. The escapement magnet 107 thereupon releases the side switch into position 3. The meter magnets 143 of the lines passed over during this testing operation do not receive sufficient current to operate them, due to the high resistance of the right-hand winding of escapement magnet 107. When the side switch moves into position 3, cutoff relay 130 is immediately operated over the following circuit: free pole of battery, relay 130, conductor 131, contact 132, brush 133, conductor 134, side-switch arm 113 and its third contact, conductor 112, armature and back contact of escapement magnet 107 to ground. The ground placed on brush 133 at the back contact of escapement magnet 107 causes this line to test busy in the connectors in which this line appears as will hereinafter appear.

The cutoff relay 1'30 upon operating causes the deenergization of line relay 108 which, at its armature and back contact, restores this line to non-calling condition by grounding its multiple test contacts 129. As the side switch moves into position 3, relay 205' at the connector is energized over the following circuit: free pole of battery, lefthand winding of relay 205, conductor 206, arm 207 and first contact of the connector side-switch, conductor 132, polarized relay 133, side-switch arm 134 and its third contact, conductor 135, finder brush 136, contact 137', line conductor 1), the telephone set of substation A. line conductor a, contact 138, finder brush 139, conductor 140, side switch arm 141 and its third contact, con ductor 142, conductor 208 side-switch arm 209 and its first contact, conductor 210, right-hand winding of relay 205 to ground.

The relay 133 is polarized so as not to operate by the closure of the circuit for relay-205 just traced. Relay 205, upon its energization, closes a circuit for slow acting relay 203 at its armature and front contact.

Relay 203, at its right-hand armature and front contact, prepares a circuit for the pri mary stepping magnet 227. The calling subscriber now operates his sender 157 and interrupts the circuit of relay 205 a number of times, corresponding to the tens digit of the number of the called line. Each time the armature of relay 205 closes its back contact a circuit for primary stepping magnet 227 is closed as follows: free pole of battery, magnet 227, side-switch arm 228,

conductors

229, 212, right-hand arn'iature and front contact of slow relay 203, conductor 201-, armature and back contact of relay 205, to ground. The magnet 22? thus moves the wiper shaft in a primary direction by a pawl and ratchet (not shown), to pick out the group in the connector to which the called line belongs. Upon the first break in the line circuit and the consequent falling back of the armature of relay 205, a circuit was closed for the sideswitch escapement magnet 231 of the conncctor as follows: free pole of battery, magnet 231, conductor 21 2, armature and front contact of relay 203, conductor 201, armature and back contact of relay 205 to ground. This magnet being slow-acting, remains energized until the closure of the line circuit at the end of the tens series of brwaks. whereupon it falls back and moves the side switch into position 2 in the wellknown manner. Arm 22S thereof, in position 2 prepares a circuit for the secondary magnet Upon the operation of the sender 157 in transmitting the units digit of the wanted number, relay 203 is intermittently deiinergized and the secondary stepping magnet moves the connector brushes to the terminals of the wanted line, the circuit being as follows: free pole of battery, magnet 232, side-switch arm 228 and its second contact.

coinlnctors

229, 212, right-hand armature and front contact of slow relay 203. conductor 204', armature and back contact of relay 205 to ground, it being understood that slow acting relay 203 remains energized as during the first series of line circuit interruptions. Escapement magnet 231 was energized upon the first closure of the back contact of the armature of relay 205 as during the tens selecting o 'ieration, and being slowacting, releases only when the series of interruptions of the line circuit corresponding to the units digit is over. It is then deenergized and moves the side switch into position 3. The selected line is inn'nediately made to test busy in the connectors in which it appears by sideswitch arm 233 grounding the multiple test contacts 23s thereof, and the cut-off relay of the called line corresponding to relay 130 of Fig. 1 is operated.

In position 3. the arm 228 of the side switch closes a circuit for the escapement magnet 231 to close the ringing circuit. This circuit is as follows: free pole of battery, magnet 231, conductor 229, arm 223 and its third contact,

conductors

235, 217, armature and back contact of ringing control relay 2.18, to ground. The escapcment magnet at its right-hand armature and front contact closes the ringing circuit as follows: free pole of ringing generator 236, ringing control relay 213, conductor 237, right-hand armature and front contact of escapement magnet 231, conductor 23S, side switch arm 23$) and its third contact, conductor 210, brush 211, terminal 226, line conductor a, bell 212. line conductor 0, terminal 225, brush 213, conductor 211, arm 215, conductor 216, conductor 221, arn'iature and front contact of relay 205, to ground. \Vhen the called party answers, the marginal relay 218 is energized and opens the circuit of the escapement magnet 231, whereupon the cscapcmcnt magnet releases the side switch into position 1, thus opening the ringing circuit. Relay 201 is now energized and talking current is supplied to the called line through the windings of this relay. It will be noted that when the side switch moves into position 4: upon the response of the called party, arms 207-, 200 of the side switch reverse the connection of the battery supplied to the calling party. The polarized relay 133 thereupon operates.

Upon the operation of polarized relay 133, it closes at its armature and front contact a circuit of sufficient strength to energize the meter magnet 143. This circuit is as follows: free pole of battery (Fig. 1), primary stepping magnet 118, conductor 144, armature and front contact of polarized relay 133,

conductors

115, 161, brush 128, contact 120, conductor 11 6, right-hand winding of meter magnet 11?), conductor 117. right-hand armature and back contact of line relay 108 to ground. The operation of magnet 113 has no ellect at this time. The Ineter magnet thereupon attracts its armature 118. The armature of meter magnet 143 carries the stepping pawl 110 of the meter which. by advancing ratchet wheel 151 a step. records the connection which has just been built up. Armature 113 at its front contact closes a locking circuit for the meter magnet as follows: free pole of battery. left-hand winding of the meter magnet 113, conductor 150, armature 11S, and front contact of the meter magnet, conductor 152, conductor 131, contact 132, brush 133. conductor 13f. side switch arm 113 and its third contact, armature and back contact of escapement magnet 10? to ground. Thus the meter remains locked until the connection is disestablished to prevent the accidental operation of the meter.

\Yhen the subscribers hang up their re" rcivers upon the conclusimi of the Quin yersation, the relays 205 and 201 at the connector are dei nergized. The following circuit for the release magnet 153 of the finder is thereupon closed: free pole of battery, release magnet 153, tinder off-normal contact 134', conductor 155, right-hand armature and back contact of slow relay 105, conductor 123, conductor 200 (Fig. 2), lefthand armature and back contact of relay 201, conductor 202, right-hand armature and back contact of relay 203, conductor 201-, armature and back contact of relay 205 to ground. In case the calling subscriber hangs up his receiver before the called sub scriber, the release circuit is the same as that previously traced up to the left-hand armature of relay 201, and from thence passes by way of front contact of said armature, conductors 211 and 212, right-hand armature and front contact of relay 203, which is slow to release its armature, conductor 201, armature and back contact of relay 205 to ground. This impulse is sufficient to energize release magnet 153, which thereupon attracts its armature and locks itself up to ground through the finder off-normal contact 1.31 until the finder completely restores, whereupon it is decnergizcd by the opening of such otf-nbrlnal contact.

When the called subscriber hangs up his recciyer, the circuit for release magnet 213 of the connector is closed as follows: free pole of battery, lett hand winding of release magnet 213, conductor 214, right-hand armature and back contact of relay 201, conductor 21-3, sideswitch arm 210 and its fourth contact, conductor 217, armature and back contact of the ringing control rclay 21b, to ground. The release magnet 2133, upon its energization, restores the side switch to its normal position and closes a locking circuit for itself as follows: free pole of battery, lclthand winding of re lease magnet 21 conductor 211, right-hand armature and back contact of relay 201. conductor 215. side-switch arm 2'10 and its third. s cond or first contact, conductor 220, connector switch olf-norn1al contact 221, conductor 222. left-hand armature and back contact of relay 20 i, conductor 223, conductor 217, lefthand armature and back contact of relay 201, conductor 202, right-hand armature and back contact of relay 203, conductor 20 t, armature and back contact of relay 205, to ground.

If the called subscriber hangs up his receiver before the calling subscriber the circuit previously traced for release magnet 213 through its left-hand winding to ground at the armature and back contact of ringing control relay 218 is closed whereupon the release magnet at its left-hand armature and front contact locks itself over the following circuit: free pole of battery, right-hand winding of release 2123, its left-hand armature and front contact,

conductors

219, 224, 218, to ground at the armature and front contact of relay 205.

In case the wanted line is busy as a called line its test terminal 23-1 is grounded by side-switch arm of another connector; if busy as a calling line, said test terminal is grounded by side-switch arm 113 and armature and back contact of escapement magnet 107 of another finder. in this event, when under the control of the sender 1 of the calling party, the connector selects such busy line, the connector is immediately released and a busy signal is given to the calling party. lt will be recalled that when the line circuit is permanently closed at the end of the last or units series of interruptions, the escapement magnet 2231 of the side switch of the connector is deciiergized and releases the side switch into position I to signal the selected line. lts left-hand armature is so arranged, however, that it closes its back contact before the side switch is released. The following circuit is then closed for release magnet 213 of the connector, if ground is present on test terminal 231 of the selected line, which will be the use if the line is busy as just explained: free pole of battery, left-hand winding of release magnet 213, conductor 21st, right-hand armature and back contact of relay 201, conductor 215, side-switch arm 210 and its second contact, conductor 220, connector off-normal contact 221, conductor 222, left-hand armature and back contact of slo\\-acting escapcl'nent magnet 231, 0011- ductor 219, side-switch arni 233 and its second contact, conductor 250, brush 251, contact 231, to ground either at the side-switch arm and its third or fourth contact of the connector connected to a multiple con tact of this line, or at the back contact of the escapement magnet 10? of a tinder connected to a multiple contact of this line. Thus the connector is rel usual. The release magnet 213 at its left-hand armature and front contact locks itself over the following circuit: free pole of battery, right-hand locking winding, left-hand armature and front contact conductors 210. 221, 218, armature and front contact of relay 205 to ground. The release nnwnet 213 at its right-hand armature and front contact ap plies a busy tone over conductors 252, 253 to the calling line.

\Vhen the calling party hangs up his receiver, relay 205 is deenergiaaed, opening at its armature and front contact the locking circuit of magnet 213, and at its back contact closing the following circuit to release the finder: ground, armature and back contact of relay 205, conductor 204. right-hand armature and back contact of relay 203, conductor 202, left-hand arn'iature and back contact of relay 201, conductors 2 17, 200,

123, armature and back contact of relay 105, conductor 155, off-normal contact 15 1, release magnet 153 to free pole of battery. The release magnet locks itself up as previously described until the finder has reached its normal position, when by the opening of off-normal contact 154, it is released.

The finders are allotted to the calling lines by an extended starter wire. Each line group has a finder whose contact brush 115 normally rests on a home segment 116 of such group, adjacent a. segment 158, also individual to such group. Thus, if a call comes in from any line in the group to which it is allotted, a single rotary step only of the brush shaft of the finder of such group is necessary to position its brushes to wipe over the terminals of such group as has just been shown. If the finder shown in Fig. 1 had been busy when the call just traced was initiated, the starter wire 104 would have been extended by finder off-nor- 11ml contact 103, bottom, to the next idle finder, which would first be given a primary rotary movement by means of its primary stepping magnet corresponding to 118 of Fig. 1 to place such finder in a position to move its brushes over the terminals of the group containing the calling line. The starting circuit for such finder would then be as follows: ground, right-hand armature and front contact of group relay 101, conductors 109, 101, off-norn'ial contact 103 bottom, conductor 180, armature and back contact of slow relay 105, conductor 159 to the primary magnet of the next idle finder. From this point the operation may be traced by reference to Fig. 1, and assuming the finder shown therein to be the idle one. The circuit then continues by conductors 160, 10$). to escapement magnet 107 and slow relay 105, from which point the operation is the same as that already traced, except that the side-switch escapement magnet 107 of such finder would lock itself up to the grounded segments 158 of the non-calling line groups. and thus maintain the stepping circuit of the primary magnet 118 of such finder closed until the brush 115 thereof reaches the segment 158 of the calling line group from which ground is removed. Magnet 10? thereupon releases the side switch into position 2 to open the circuit of such primary stepping magnet and close the circuit of the secondary stepping magnet 100 of such finder to move the wipers over the calling group. From this point on, the operation is the, same as that already described.

lVhile in the present embodiment of the invention, the meter is operated upon the response of the called party, it is within the scope of the invention to operate the meter at some other stage in the process of building up or disestablishing the connection.

\Vhen the invention is applied to semi-automatic systems the polarized relay 133 may be under the control of the operator at the central ofiice. For simplicity, no intermediate selectors have been shown. It is obvious however, that in actual practice a number of such selectors would be interposed between the finder shown in Fig. 1 and the connector of Fig. 2 depending upon the size of the exchange.

What is claimed is:

1. In a telephone exchange system, the combination with telephone lines, automatic fin-der switches wherein said lines terminate in multiple contacts, multiple test contacts for said lines in said finders, of meters connected with said test contacts and each provided with an operating winding of low resistance, a high resistance test circuit associated with each of said finders, an operating circuit for said meter magnets associated with each of said finders, and means operated upon the response of the called party for closing said operating circuit to actuate the calling line meter.

2. In a telephone exchange system, the combination with telephone lines, automatic finder switches wherein said lines terminate in multiple contacts, multiple test contacts for said lines in said finders, of meters connected with said test contacts and each provided with an operating winding of low resistance, a test circuit associated with each of said finders including a test relay of relatively high resistance, an operating circuit for said meter magnets associated with each of said finders, and means operated upon the response of the called party for closing said operating circuit to actuate the calling line meter.

In a. telephone exchange system, the combimition with telephone lines, means for interconnecting the same including auto matic finder switches wherein said lines terminate in multiple contacts, multiple test terminals for said lines in said finders, of meters for said lines connected to said test terminals and provided with a double wound magnet having an operating winding of low resistance and a locking winding, a high resistance test circuit for each of said finders, an operating circuit for said meter magnets associated with each of said finders, and means actuated upon the response of the called party for closing said operating circuit to actuate the calling line meter, whereupon said meter magnet locks itself up by means of its locking winding.

4. In a telephone exchange system, the combination with telephone lines, means for interconnecting the same including automatic finder switches wherein said lines terminate in multiple contacts, multiple test terminals for said lines in said finders, of meters for said lines connected to said test terminals and provided with an operating magnet of low resistance, a test circuit for each of said finders including a test relay of relatively high resistance, an operating circuit for said meter magnets associated with each of said finders and a polarized relay operated upon the response of the called party for closing said operating circuit to actuate the calling line meter.

5. In a telephone exchange system, the combination with telephone lines, means for interconnecting the same including automatic finder switches wherein said lines terminate in multiple contacts, multiple test terminals for said lines in said finders, of meters for said lines connected to said test terminals and provided with an operating magnet of low resistance, a test circuit for each of said finders including said meter magnet and a test relay of relatively high resistance, and an operating circuit for said meter magnets associated with each of said finders.

(3. In a telephone exchange system, the combination With telephone lines, finder switches wherein said lines terminate, normally-grounded multiple test contacts for said lines in said finders, a line relay for each line adapted when operated to remove ground from its multiple test contacts, steering switches for said finders, high resistance escapement magnets therefor, a test circuit for each finder including its escapement magnet, means for causing one of said finders to wipe over said test contacts and for energizing its escapement magnet upon the operation of any of said line relays, circuits for maintaining said magnet energized including grounded non-calling line test contacts, whereby when the test brush reaches the non-grmmded calling line test contact said magnet is decnergizei'l to move the associated steering switch to open the finder driving circuit, means operated by the stopping of the finder for replacing ground upon the calling line test terminals, :1 low resistance meter magnet for each line connected to its multiple test contacts, and means operated upon the response of the called party for closing an operating circuit for the talling line meter magnet.

In witness whereof, I hereunto subscribe my name this 2] st day of April, A. D. 1915.

CHARLES L. GOODRUM.

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