US1442086A - newforth - Google Patents

Description

Jan. 16, 1923.

F. NEWFORTH, JR. AUTOMATIC'TELEPHONE SYSTEM.

3 SHEETS-SHEET l.

ORIGINAL FILED SEPT- IB, 1914.

; Ffank NBA/farm J1" HZZUTHE Jan. 16, 1923, 1,442,086.

' F. NEWFORTH, JR.

.AUTOM'ATIC TELEPHONE SYSTEM.

ORIGINAL FILED SEPT. 8. i914. 3 SHEETS-SHEET 2.

Jan. 16, 1923.

F. NEWFORTH, JR.

AUTOMATIC TELEPHONE SYSTEM.-

ORIGINAL FILED SEPT-18. 19M. 3 SHEETS-SHEET 3.

F M] 5??? F527 aw gr 1:

H H urn'ay Patented Jan. 16, 1923.

UNITED stares PATENT OFFIE.

FRANK nnwron'rn, m, or noawoon, or-IIo, nssrenoa r0 AUTOMATIC ELECTRIC COMPANY. or CHICAGO, ILLInoIs, A. 'CQRPORATION or ILLINOIS.

AUTOMATIC TELEPHONE SYSTEM.

Original application filed September 18, 181-1, Serial No. 862,292. Patent No. 1,256,817, dated February 19,1918. Divided and this application filed February 4, 1918.

To (ZZZ whom it may concern.-

ie it known that I, Emmi; Nnwroirrn, J12, citizen of the United States of America, and resident of Norwood, county of Hamilton, Ohio, have invented certain new and useful Improvements in Automatic Telephone Systems, of which the following is a specification.

My invention relatesto automatic telephone systems in general. More particularly it relates to systems in which trunk selecting apparatus is employed and in which traffic trunks are used. in connection therewith. Among the special objects of my invention are the following:

To provide in a measured service reverse battery telephone system a traffic line terminating in an operators position, which operator upon responding automatically cuts oil the ringing current in the calling connector without operating the meter associated with the calling circuit; to provide an improved type of trunking switch; and to provide certain details and features of improvement tending-to increase the efficiency and serviceability of a system of the above character.

The means to accomplish the foregoing and other useful ends are hereinafter set forth and claimed.

In the accompanying drawings Figs. 1 and 2 taken together show a connection establishedbetween a calling automatic substation A and the lines of a called automatic substation A.

In Fig. 1 there is shown the automatic substation A, line switch 0, a meter X assoc'ated with. the line and a first selector switch E.

In Fig. 2 there is shown a connector .vitcli H, and line switch 0 of substation 1.. There is also shown at J a group of relays which may be located in a manual board and are for the purpose of allowing an operator to answer an. information call or the like without operating the meter of the calling. line as will be hereinafter more fully explained.

Figs. 3 ands represent in detail a portion of a so-called self aligning line switch plunger, that is aline switch plunger which will at all times return to its normal posi- Serial No. 215,239.

tion on the controlling shaft regardless of the position of the shaft.

- Fig. 5 represents in detail a portion of a master switch showing the association of the line switch plungers therewith.

The automatic substation A (Fig. 1) com prises the usual receiver 2, transmitter 3, ringer l and condenser 5. Being an automatic substation, it is also provided with a suitable impulse sending mechanism for controlling the automatic switches, which mechanism is represented diagrammatically by a pair of impulse springs 6 and 7 and an impulse wheel 8, which may be controlled in a well known manner through the me- .dium of a dial (not shown) provided with finger holes in such a way that the impulse springs may be momentarily separated anumber of times corresponding to the respective digits of the number of the called subscriber. I

The subscribers individual switch C is of the general type of subscribers switch 'shown in British patent to R. W. James,

#26301 of 1906, more closely resembling, however, the particular type shown in British patent to T. G. Martin, #1419 of 1910. This line switch comprises, among other details, a plunger 200 shown in Figs. 3, 4 and 5 pivotally attached to the end of a so-called plunger arm 9. The back portion of this plunger 200 is fan shaped. Pivotally mounted on this fan shape portion at the points 201 and 201" there are two arms, 202 and 202. These arms 202 and 202 are limited in their rotation by two pins 203 and 203, at their outer ends they are provided with rollers 205 and 205 which engage the flange 206 on the usual shaft 207. when the plunger 200 is in normal position. The arms 202 and 202 are held in this position by means of a spring 208, one end of which is securedto each arm. hen the plunger is operated as shown in Fig. 4: the shaft 207 is rotated in the usual and well known man ner and operates to force the arm 202 away from the retaining pin 203 The arm 202 however is prevented from rotating by means of the pin 203. Thus it will be seen that when the shaft 207 is r otated, at the time the plunger is in an operated position,

the spring 208 will be placed under tension and the plunger held against rotation and when the plunger is released, it operates through the medium of the arms 202 and 202*, to bring the plunger back to its normal position, that is, until the arms 202 and 202 engage their respective stop pins 203 and 203. by a magnet 10, which comprises an oper ating winding 11 and a holding winding 12. This magnet also controls the cut-off armature 13. The winding 11 operates both the plunger arm 9 and armature 13, while the winding 12 is strong enough only to operate the armature 13 and to hold the plunger arm 9 in its operated position. i/l hen the plunger arm 9 is operated its plunger is forced into a bank of contact springs, forcing the springs 14:, 15, 16 and 17 into engagement with the springs 18, 19, 20 and 21, respectively. Although only one set of springs l t-21., is shown, each line switch is provided with a plurality of such sets, each set forming the terminal of a trunk line leading to a first selector switch E. Each trunk line is connected in multiple to the corresponding springs of all the line switches of the group which is controlled by the master switch D. The switch C is controlled by the subscriber through the .medium of the line relay 22, which relay is preferably slow acting, that is, slow to release its armature upon deenergizing. This relay instead of being connected directly to battery as is usually the case is connected to battery through the springs 60, 61 controlled by the plunger arm 9. The purpose of connecting relay 9 in this manner will be hereinafter pointed out.

The master switch D is of the general type of master switches shown in British Patents #26301 of 1906, and 1&19 of 1910. The function of the master switch, as is well known, is to maintain the plungers of all the idle line switches in position to engage the terminals of an idle trunk line. Referring to Fig. 5, the master switch 1) consists essentially of a motor magnet 1 which operates the ratchet wheel 355, a bank of contacts comprising a number of individual segments a and one common segment 356, a busy trunk relay 357, and a locking relay 358. The wiper 359 is adapted to always keep some one of the individual segments in an electrical connection with the conunon segment 356. By means of a suitable mechanical connection the rotary motion of the ratchet wheel 355 is transmitted to the plunger shaft to give said shaft a reciprocating motion to move the idle plungers back and forth in front of the bank contacts. To the plunger shaft there is also secured a cam 360 having in its surface a number of circular openings which are engaged by the pin 361 on the The plunger arm 9 is controlled eaaose armature 362. The openings in the cam 360 are so spaced that the pin 361 can engage an opening only when the plungers that are in looking engagement with the plunger shaft are directly in front of a trunk terminal.

Associated with the line A there is shown a. call register 23, which is controlled by a double wound magnet 29. The windings of the magnet 29 are so proportioned that it requires the energization of both windings in the same direction to attract the armature, said armature being unaffected by the energization of either winding alone, or by the energization of the two windings in opposition to each other.

The first selector switch E is of the gen eral type of selector switches disclosed in T]. S. Letters latent to Keith, Erickson and Erickson, #815,321, granted March 13, 1906. Among other details, the selector E comprises a bank of contacts arranged in horizontal rows or levels, which are adapted to be engaged by a set of wipers 30, 31 and 32 car--7- ried upon a shaft (not shown), which has a vertical movement controlled by the vertical magnet 33 and a rotary motion controlled by the rotary magnet 34. The operations of the switch are controlled through the medium of the double wound 95 line relay 35. Means for permitting the switch to be restored to normal position are provided in the release magnet 36, which, upon energizing, withdraws the retaining pawls from the shaft. The spring 100 contacts 37 and 38 are permitted to close only when the switch shaft has been raised one or more steps from its lowest position. The relays 39 and 410 are slow acting relays, that is, relays which de-energize slowly 105 after their energizing circuits are broken. This slow action is usually obtained by placing a ring of copper around one end of the core of the relay.

The connector shown at H (Fig. 2) is of 110 the general type of connector switch disclosed in U. S. Letters Patent to Keith, Erickson and Erickson, :H'815,176,.the circuits, however, being modified to adapt the switch to operate in a system in which the 115 central oflice apparatus is controlled by impulses delivered over the two sides of the line in series. Like the selectors, the connector is provided with a shaft (not shown) carrying the wipers 41, 12 and 43, and which 3 is controlled by the vertical magnet 14 and rotary magnet 15. The usual side switch comprising the wipers 16, 47, 1S and 19 is controlled by the private magnet in the usual and well known manner. Magnet 53 25 is the usual release magnet. The line re lay 51 is connected with the line through the reversing springs of a so-called back bridge relay 52, through the windings of which latter relay the called line is provided 130 with talking current. The ringer relay 253 is the means through which the application of ringing current to the called line is controlled. At Q there is shown a busy signaling machine which is connected to springs of relay 55, the function of which is to send a busy tone under certain conditions back over the line. The complete operation of this relay will be described later. The busy signaling machine as represented herein, comprises an induction coil or transformer, the primary winding of which is included in a local circuit with a battery and an interrupter. Through the medium of this interrupter an intermittent interrupted current is supplied to the primary winding which induces an intermittent al ternating current in the secondary winding whereby when said winding is connected to the subscribers line an intermittent buzzing sound is heard in the receiver.

The line switch C is similar to the line switch 0 the circuits being modified, however, as will be hereinafter more fully explained.

The substation A is similar in all respects to the substation A.

For the purpose of supplying current for operating the central oflice apparatus and for talking purposes there is shown abattery 13 having one terminal grounded at G.

In the event of a subscriber having his telephone removed or taken out of service for non-payment or other numerous reasons, his line is disconnected from the central o'tlice apparatus and the contacts of the connector bank constituting the terminals of said subscribers line are wired to what is known as a traffic trunk as shown at J in Fig. 2, the conductors of said trunk being designated by the reference numerals 165 and 166. Therefore, upon the subscriber at substation A. attempting to call a subscriber whose telephone it has been assumed has been taken out of service he will signal an operator who will give him the necessary information. It is desirable that such a call be not charged to the calling substation, therefore, arrangements are provided in the group of relays shown at J, Fig. 2, for the preventing of the operation of the meter of the calling substation when a call similar to that above mentioned is made.

A general description of the apparatus having been given it will now be explained how a connection may be established between a calling automatic substation A and a called automatic substation A, the number of which we will assume to be 220, and also how the meter is prevented from being operated when the subscriber at substation A attempts to call substation A (not shown.) whose line has been connected to the above mentioned traffic trunk. Upon the removal of the receiver from the switch hook at the calling substation preparatory to making a call, the talking circuit of the substation is bridged across the line conductors 71 and 72 by the hook switch springs 73 and 7 1, whereby the circuit of the line relay 22 of the switch C is closed. This circuit extends from ground G through the springs 75 and 76, line 71, substation A, line 72,

idle first selector switch E. The line relay' of the selector switch E is thereupon energized over a circuit extending from ground G through the lower winding of said relay, springs 82 and 82 thence over the heavy conductors to and through the substation A and back over the other side of the line through the left hand winding of the meter magnet 29, springs 83 and 83 and upper Winding of line relay 35 to the battery lead 80. The relay 35, upon energizing, closes the circuit of the relay 39, which in turn, upon energizin closes a circuit extending from ground 4 through the springs 85, line switch bank springs 20 and 16 and holding winding 12 to the battery lead 80. The energization of this winding serves to hold the switch C in its operated position after the circuit of the winding 11 is broken by the relay 22, which de-energizes shortly after it is disconnected from the line. The energization of the relay 39 at the selector E also completes a circuit extending from ground G through springs 85, springs 20 and 16, through the right hand winding of the meter magnet 29 and the springs 61 and 61 to the battery lead 80. The current in this winding is in opposition to the current flowing through the line winding, and the magnet is, therefore, not operated at this time. At the same time, a guarding potential is extended from ground G at the selector via conductor 80 to the connector private bank contact of the calling line in the bank of each of the connector switches whichhave access thereto.

The springs and 61 disengage immediately upon the operating of the plunger arm 9 which prevents the circuit of the line relay 22 from again being closed until the plunger arm 9 is again restored to normal position in front of an idle terminal.

Upon the closure of the springs 17 and 21 by the operation of the switch C, the master switch D operates in a well known manner to advance the plungers of the idle line switches to a position opposite an idle trunk line.

The calling subscriber now operates his calling device for the first digit 2 of the called number, whereby the substation impulse springs 6 and 7 are separated twice momentarily, each time breaking the circuit of the selector line relay 35. The relay 39 of the selector, being slow acting, does not deenergize during the momentary interruptions of its circuit by the relay 35, and consequently each time the latter relay deenergizes an impulse is transmitted over the circuit extend ing from ground G through the springs 88 and S9, 90 and 91, relay 40, vertical magnet 33 and side switch wiper 62 to the battery lead 80. The vertical magnet receives two impulses over this circuit and operates to raise the switch shaft and wipers two steps to a position opposite the second row or level of bank contacts, and at the same time the shaft controlled contacts 37 and 38 are closed. The slow acting relay 10 is maintained in its energized position continuously while impulses are being transmitted to the vertical magnet through it, and in its ener ized position closes a circuit from ground (3 through the springs 9a and 93 and private magnet 95 to the battery lead 80. The relay 10, upon deenergizing, opens the circuit of the private magnet 95, which in turn, deenergizes and allows the side switch to pass from first to second position. The wiper 62, upon passing from first to second position, closes an energizing circuit for the rotary magnet 3 This circuit extends from ground G through interrupter springs 97 and 98, rotary magnet 34-, wiper 62 to battery B. The rotary magnet, upon energizing, operates to rotate the shaft and shaft wipers one step onto the first bank contact of the level in which the trunk lines leading to a connector H terminate. The rotary magnet upon energizing operates to break its own circuit at the interrupter springs 97 and 98 and to again close the circuit of the private magnet. The circuit for the private magnet extends from ground G through springs 99 and 100, and the private magnet 95 to battery B. If the first trunk line leading from the second level of bank contacts of the selector E is in use, the private wiper 32 will find the first private bank contacts supplied with a guarding ground potential, a circuit will then be closed through the private magnet 95 after the rotary magnet dcenergizes, extending from said ground at the private wiper through the side switch wiper 63 (in second position), and then through magnet 95 to battery. The side switch is thus held in second position and the rotary magnet upon deenergizing again. closes its own circuit at springs 97 and 98 and operates to step the shaft wipers to the next bank contacts. If the next contacts are also busy the operation will be repeated, the rotary magnet operating in a manner similar to that of a buzzer to rotate the shaft wipers onto bank contacts connected to an idle trunk line, at which time the private magnet deenergizes and allows the side switch to pass from second to third position. The wiper 62, upon pasing to third position shifts the battery connection from the rotary magnet 34c to the line switching relay 102, thus closing a circuit through the relay 102. This circuit extends from ground G through springs 85, relay 102 and wiper 62 to battery B. A circuit also extends from springs 85 through wiper 63 (in third position) to the private wiper 32. The relay 102, upon energizing, operates to disconnect the line relay 35 from the line and to connect the calling line through to the line relay 51 of the connector H, and also operates to open the circuit of the release magnet 36 at springs 103 and 10 1. The line relay, upon being disconnected from the line deenergizes and allows the relay 39 to deenergize. The relay 39, being slow acting, does not fall back however, until a ground has been supplied to the release trunk conductor 1 10 by the relay 160 of the connector switch H as will be later more fully explained.

The line relay 51 of the connector thereupon becomes energized and closes the circuit of the relay 160, The relay 160, upon energizing, provides a holding circuit for the line switching relay 102 of the selector switch E, and for the hold in winding 12 of the line switch C. The circuit for the line switch ing relay 102 extends from ground G through the springs 123, conductor 14-0, wiper 32, side switch wiper 63, relay 102 and the side switch wiper 62 to battery 13. The circuit for the hold in winding 12 extends over the above traced circuit to side switch wiper 63, thence through bank contacts 20 and 16 and the said hold in winding to battery B.

When the substation calling device is operated for the digit 2, the circuit of the connector line relay 51 is broken twice. Since the relay 160 is slow acting, it does not deenergize during the momentary interruptions ofits circuit by the relay 51, so that each time the latter relay is deenergized a circuit is closed extending from ground G through the springs 162 and 162 springs 163 and 163, relay 16a, vertical magnet H and side switch wiper 19 to the battery lead 80. The vertical magnet 1 1 receives two impulses over this circuit and operates to raise the switch shaft wipers 11, 42, and 413 to a position opposite the second level of bank contacts. The relay 164, which is included in series with the vertical magnet, remains in its energized position during the entire time impulses are being transmitted through it and operates to close the circuit of the private magnet 50. After the last impulse is delivered the relay 16% opens the circuit of the private magnet 50, which upon deenergizing, permits the side switch to advance from first to second position. The movement of the side switch wiper 49 from first to second positiontransfers the battery connection from the vertical magnet 44 to the rotary magnet 45. The calling subscriber now operates his calling device for the last digit 0 in response to which the connector line relay 51 operates to transmit ten impulses through the rotary magnet 45, in series with the relay 164, whereby the shaft wipers are rotated onto the.contacts of the desired line. The relay 164 operates in response to this digit in thesame manner as for the previous digit, to cause the private magnet 50 to advance the side switch one more position, that is, from second to third position after the last impulse for the digit is transmitted. By the engagement of the side switch wipers 46 and 47 with their third position contact points the line connection is finally completed to the called number.

I will first give a description of the operations that take place, assuming that connection was established to the called telephone in which case the wipers 41, 42 and 43 would be in engagement with conductors 167, 168 and 169 respectively. The circuit of the relay 170 of the called )artys line switch is closed by the side switc wiper 48 passing to third position, said circuit extending from to battery B.

ground G through side switch wiper 48, private wiper 43, conductor 169 and through. the relay 170 to battery. The connection of ground G with the connector private bank contact of the called line over the portion of the circuit just traced provides said contact with a guarding potential to prevent the busy line from being connected with by other connector switches. By the engagement of the side switch wiper 49 with its third position contact point the circuit of the ringing relay 253 is closed, which circuit extends from ground G through the interrupter 171, relay 253, springs 172 and side switch wiper 49 to the battery B. The ringing relay 253, upon energizing, disconnccts the calling from the called line and bridges the ringing current generator M across the called line to signal the called subscriber. The ringing relay is energized only intermittently through the medium of the interrupter 171. Upon the response of the called subscriber his line is provided with talking current through the windings of the back bridge relay 52 of the connector switch, which relay upon energizing, closes the circuit of the ringer cut-out relay 174. This circuit extends from ground G through the wiper 48, springs 175, and the said relay 174 The relay 174, upon energizing, opens the circuit of the ringing relay 253 at the springs 172 and closes a locking circuit for itself through its own springs 176 independent of the springs of the back bridge relay 52. A further result of the energization of the relay upon the response of the called subscriber, is the transposition of the connection between the windings of the line relay 51 and trunk conductors 138 and 139, whereby the direction of current in the calling line is reversed. This reversal of the current in the left hand winding of the subscribers meter relay 29 (Fig. 1) causes the two windings to assist one another to operate the meter to register the call.

After the conversation is completed the connection is released by the hanging up of the receiver at the calling substation in the following manner: When the receiver at the substation A is restored to the switch hook, the separation of the hook switch springs 7 3 and 74 destroys the energizing circuit of the line relay 51 (Fig. 2). The relay 51, thereupon deenergizes, andopens the circuit of the relay 160. The relay 160, upon deenergizing, opens the holding circuits of the relay 102, of the switch E and of the hold in winding 1.2 of line switch C and at the same time closes the circuit of the release magnet 53 of the connector H. The latter circuit extends from ground G through the springs 162 and 162 springs 163 and 122, shaft controlled springs 178 and the said release magnet 53 to the battery B. The magnet 53, upon energizing, restores the connector switch shaft and side switch to normal position, and its own circuit is interrupted at the springs 178 when the shaft reaches its lowest position. The deenergization of the relay 102 of the switch E serves to close the circuits of the release magnet 36. The circuit for the said magnet extends from ground G through the springs 88 and 89, springs 90 and 90 springs 104 and 103, ofl normal springs 38 and 37 and the magnet 36 to battery B. "When the shaft reaches its lowest position the circuit of the magnet 36 is opened by the separation of the off normal springs 38 and 37. The hold in winding 12, upon deenergizing, allows the plunger arm 9 and cut-off armature. 13 to return to normal. Thus it will be seen that everything is released and in readiness for another call.

If the called line had been in use the calling subscriber would have received the busy signal in the following manner: The private wiper 43 upon coming to rest upon the private bank contact of the called line would have found said contact grounded, whereby a circuit would have been closed extending from said ground, tl'irough wiper 43, side switch wiper 48, (in second position) springs 185 and 186, relay 55, springs 188 and 187, and the private magnet 50 to battery B. The relay 55, upon operating, opens the circuit of the rotary magnet at the springs 190 and closes a lochingcircuit for itself extending from ground G through springs 189, springs 191 and 186, and over the circuit above traced to battery B. The engagement of springs 192 and 193 places a busy signal from the machine Q, onto the calling line. The calling subscriber, upon receiving the busy signal replaces his receiver upon the hook thereby releasing the connection in the manner similar to that hereinbefore explained.

It will now be explained how the calling subscriber can, after obtaining connection with the lines of the substation A whose telephone has been discontinued, converse with an operator Without having the call registered. As has been explained, if the service of the called substation has been discontinued, then the normal conductors of said substation will be disconnected from the telephone line and connected to the traflic trunk 165 and 166. Thus when the connector comes to rest upon the called number, that is, when the wipers 4:1 and 42 come to rest on the terminals of the trafiic trunk conductors 165 and 166, the relay 190 is bridged across the conductors 191 and 192, thereby being placed in the circuit with the back bridge relay 52. The relay 190; energizes over this circuit, but is of sufficient resistance to prevent the relay 52 from operatively energizing. The relay 190*, upon energizing, closes a circuit through the lamp 198. The operator, upon noting the glowing of the lamp 198 operates the key K thereby placing the talking set across the conductors 165 and 166 and also, due to the make before break arrangement of the springs 194, 195 and 196, sends one impulse from ground G through the primary of the induction coil 197 to battery. This impulse induces an impulse in the secondary of the coil 197, which is in series with the coil 198. The relay 198 is energized by this impulse and operates to momentarily short circuit the conductors 165 and 166. The back bridge relay 52 is momentarily energized due to this short circuiting of conductors 165 and 166 and operates to close the circuit of the ringer lock-out relay 174:, which, in turn operates, as has been explained to open the circuit of the ringing relay 253, thereby disconnecting the ringing current from the line. The momentary reversal of current by the operating of relay 52, however, is not of sufficient duration to operate the meter, thus preventing the call from being registered. The engagement of the springs 194 and 196 closes a circuit through the relay 199, which, in turn operates to break the circuit of the lamp 193 and to also place the coil 210 in series with the relay 190 this being effective to increase the impedance across the conductors 165 and 166.

The release of this connection is made in the same manner as hereinbefore explained.

The line switch shown at C (Fig. 2) operates over a circuit slightly different from that explained for line switch C. When the receiver at substation A is removed preparatory to making a call a circuit is closed extending from ground G through springs 211 and 212, conductor 213, thence through substation A, conductor 214, springs 215 and 216, windings 217 and 218 in series to the battery B. The current through these windings is not of sufficient strength to attract the plunger arm 222 but however, does attract the armature 219 and is sufficient to hold the plunger in its attracted position when once operated. The operation of the armature 219 closes a circuit for the coil 218 extending from ground G through springs 223 and 224, which are controlled by the master switch, thence through springs 225 and 226, springs 220 and 221, and the wind ing 218 to battery B. The arm 222 is now attracted and operates to force the plunger into the bank of contacts as described for switch C, separates the springs 225 and 226 and causes the engagement of springs 227 and 228. The separating of contact springs 225 and 226 disconnects the ground from winding 218. The engagement of springs 227 and 228 again places the windings 217 and 218 in series, over a circuit extending.

from the ground at the release trunk conductor 229 through springs 227 and 228 and the said windings 217 and 218 to battery B, thereby retaining the arm 222 in an operated position. It will be seen that when the plunger arm breaks the contact of springs 225 and 226, thereby disconnecting ground G from the winding 218, the plunger is held in its operated position by the original energizing circuit from ground G over the substation line and through the windings 218 and 217 in series to battery B until the release relay of the selector has time to energize and connect ground to conductor 169. The energization of the relay 170 disconnects the windings 217 and 218, and ground G from the line. The relay 170, being slow acting, prevents the line switch from again immediately operating until the plunger has had time to return to normal position after the calling subscriber has released.

It will thus be seen that I have provided an improved automatic telephone system of the measured service common battery type in which the meter is operated by the reversal of the current when the .called subscriber answers. WVith this improved form of system a discontinued subscriber at the central office can be connected with a traffic trunk associated with an operator and the operator can answer and thereby cut 011 the ringing current at the connector without permitting the current of the calling side of the line to be reversed for a sufficient length of time to operate the meter. It will be noted that when a call is extended to a traffic trunk or trouble operator, the momentary reversal and restoration of the current in the calling line will give a double click or signal in the calling subscribers receiver in place of the customary single click which occurs when the call is extended to called subscriber. The calling man may be instructed to note this signal and hang up in case the double signal is received.

I have further provided an improved form of self aligningtrunking switch which enables a subscriber to release a connection and immediately remove his receiver without causing the switch to establish a connection with a busy trunk.

l urthermore I provide an improved form of self aligning plunger type switch in which the plunger is always in engagement with the plunger shaft regardless of whether the plunger is holding the line in engage-v ment with a trunk or not and which is more positive and efficient in its action.

lVhile I have illustrated my invention in connection with a special or particular type of apparatus and circuits, I do not wish to be limited to the exact structure shown and described.

What I claim as my invention is:

1. In a telephone system, a calling and a called subscribers line, means for establishing a connection between said lines, a meter for said calling line, means for automatically applying ringing current to the called line, means ror automatically disconnecting said ringing current from the called line and for operating said calling line meter when connection has been established with the called line, a trailic trunk terminating in an operators board, means for establishing connection from said calling line to said tIELlllC trunk and for automatically applying ringing current thereto, and means controlled by the response of the operator for automatically disconnecting the ringing current from the trailic trunk without operating said calling meter.

.2. In a telephone system, a plurality of 'isibers lines, an automatic connector switch provided with bank contacts in which a plurality of said lines terminate, a traiiic trunk connected with certain of said bank contacts, means for extending connection from one o1 said lines to said connector, means for then operating; said connector to establish a connection with. another of said subscribers lines, means in said connector for automatically applying ringing current to said called line, a meter on the calling line, means controlled by the response of the called subscriber for automatically disconnecting the ringing current from the called line and for operating the meter, means for operating said connector to establish connection with said tratrlc trunl: and applying ringing current thereto,

an operators set adapted to be connected with said trunk, and means controlled upon the response ol said operator for disconnecting said ringing current from the trunk without operating said meter.

3. In a telephone system, a line, a meter in said line, an automatic connector switchconnected with said line and provided with bank contacts, a plurality oi subscribers lines connected with certain of said contacts, a trafiic trunk connected with other or said contacts, an operators set adapted to be connected with said trai'iic trunk, a source of ringii'ig current, means for automatically connecting said ringing current with. said contacts when said connector establishes connection therewith, a relay in said connector, means for causing a continuous flow of current through said relay to energize the same when connection is made with a subscribers sponds to operate the meter, means for en ergizing said relay only momentarily upon the response of the operator when connection is established with the traflic trunk, and met ns controlled by the momentary energization of saidrelay for disconnecting the ringing current from said contacts without operating the meter.

l. In a telephone system, a subscribers line, a trunk line, a connector switchaccessible to said line for connecting with said trunk line, automatic ringing equipment in said connector switch, a measured service device associated with said subscribers line, a device in said connector for preventing the operation of said equipment, said devices having different time constants, a relay in said connector for operating said devices, and means for closing a bridge across the said trunk line to operate said relay in said connector, said means also for opening said bridge before said measured service device has operated.

In a telephone system, a subscribers line, a trunk line, a connector switch accessible to said line for connecting with said trunk line, automatic ringing equipment in said connector switch, a meter associated with said subscribers line, a relay in said connector for preventing the operation of said equipment, said relay operating more rapidly than said meter, a second relay in said connector for operating said meter and for initiating the operation of said first relay, and means for closing a bridge across said trunl-c line to operate said second relay, said means also for opening said bridge to deenerglize said second relay before said meter has operated.

6. In a telephone system, the comb-ination witha calling subscribers line and a measured service device associated therewith, o. a trunk line leading to an operator-"s position, a link circuit for connecting line and said. subscriber resaid line and trunk line, automatic ringing link tor operating said device and for in-' itiating the operation of said first relay, said first relay adjusted to operate more quickly than said device, and means for closing a bridge across said trunk line to operate said second relay, said means also for opening said bridge to deenergize said second relay before said device has operated.

7. In a telephone system, the combination with a subscribers line and a measured service device associated therewith, of a trunk line, a connector switch, means for operating said switch over said subscribers line to connect with said trunk line, a source of ringing current, a relay in said connector for applying said source to said trunk line when connection is established therewith, a second relay in said connector for operating said device and for preventing the operation of said first relay, and means in said trunk line for closing a bridge across the same to operate said second relay, said means also for opening said bridge before said device has operated.

8. In a telephone system, a calling and a called subscribefs line, means for establishing a connection between said lines, a meter for said calling line, means for automatically applying ringing current to the called line, means for automatically disconnecting said ringing current from the called line and for operating said calling line meter when connection has been established with the called line, a traffic trunk terminating in an operators board, said first means also for establishing connection from said calling line to said trafiic trunk and for automatically applying ringing current thereto, and means for disconnecting the ringing current from the traffic trunk without operating said calling meter.

9. 111 a telephone system, a plurality of :nibscribcrs lines, an automatic connector switch provided with bank contactsin which a plurality 01" said lines terminate, a trafiic trunk connected with certain of said bank contacts, means for extending connection from one of said lines to said connector, means for then operating said connector to establish a connection with another of said subscribers lines, means in said connector for automatically applying ringing current to said cal ed line, a meter on the calling line, means controlled by the response of the called subscriber for automatically disconnecting the ringing current from the called line and for operating the meter, means for operating said connector to establish connection with said traffic trunk and apply ringing current thereto, an operators set adapted to be connected with said trunk, and means for disconnecting the ringing current from the traflic trunk without operating said callin g meter.

' 10. In a telephone system, an automatic connector switch, a line with which said switch is adapted to make connection, a relay in said switch, a second relay bridged across said line and adapted to be connected in series with said first relay when said connector establishes connection with said line, said second relay being of high resistance to prevent energization of said first relay, a trunk terminating in said connector switch, a meter associated with said trunk, means for short circuiting said high resistance relay to thereby cause the operation of said first rclay, and means for automatically preventing said first relay from operating said meter.

11. In a telephone system, an automatic connector switch, a line with which said switch is adapted to malre connection, a relay in said switch, a second relay bridged across said line and adapted to be connected in series with said first relay when said connector establishes connection with said line, said second relay being of high resistance to prevent energization of said first relay, a trunk line extending to said connector switch, a meter associated with said trunk, means for short circuiting said high resistance relay to thereby cause the operation of said first relay, means for applying ringing current to said line when connection is established therewith, and means controlled by the energization of said first relay for disconnecting said ringing current from the line and "for preventing the operation of said meter.

12. In a telephone system, an automatic connector switch, a line with which said switch is adapted to inalre connection, a relay in said switch, a second relay bridged across said line and adapted to be connected in series with said first relay when said connector establishes connection with said line, said second relay being of high resistance to prevent energization of said first relay, means for short circuiting said high resistance relay to thereby cause the operation of said first relay, means for automatically connecting ringing current to said line when connection is established therewith, a trunk line extending to said switch, a meter associated with said trunk line, means controlled by the energization of said first relay for disconnecting said ringing current irom the line and for reversing the current in said trunk, and means for preventing the reversal of said current from operating said meter.

13. In an automatic telephone system, an automatic connector switch provided with bank terminals, means for operating said connector to establish connection with one of said terminals or for establishing con- .nection with another of said terminals, a trunk line extending to said connector switch, a meter operable over said trunk, arelay in said connector, automatic means for holding said relay energized while the connector maintains connection with the first one of said terminals to reverse the current in the trunk line for operating said meter, and means for only momentarily energizing said relay to prevent the operation of said meter while the connector maintains connection with the second one of said terminals.

14. In a telephone system, an automatic connector switch provided with sets of bank contacts, a plurality of subscribers lines connected with certain of said contact sets, a traffic trunk connected with another of said contact sets, an operators telephone set adapted to be connected with said traflic trunk, a source of ringing current, means for automatically connecting said ringing current with any contact set when said connector establishes connection therewith, a trunk terminating in said connector, a meter associated with said trunk, a relay in said connector, means effective if a subscribers line is called for holding said relay energized while the subscribers are talking for operating said meter, and means responsive to the connection of said operators set in case a connection is extended to said traffic trunk for only momentarily energizing said relay to prevent the operation of said meter and yet disconnect the ringing current from the associated contacts.

15. In a telephone system, an automatic connector switch, a line with which said switch is adapted to make connection, a relay in said switch, a second relay bridged across said line and adapted to be connected in series with said first relay when said connector establishes connection with said line, said second relay being of high resistance to prevent energization of said first relay, a, trunk terminating in said connector switch, an electromagnetic meter associated with said trunk, means for short circuiting said high resistance relay to thereby cause the operation of said first relay, and means for preventing said first relay from operating said electromagnetic meter.

.16. In a telephone system, an automatic connector switch, a trunk line terminating in said switch, an electromagnetic meter associated with said trunk line, a line with which said switch is adapted to make connection, a relay in said switch, a second relay bridged across said line and adapted to be connected in series with said first relay when said connector establishes connection with said line,

said second relay being of high resistance to prevent energization of Slfld fir t relay when the two are connected in series, a third relay controlling a short-circuit about said second relay, and means for transmitting an induced impulse. through said third relay to thereby cause said third relay to momentarily short circuit said second relay to thereby cause only the momentary operation of said first relay to prevent the operation of said electromagnetic meter.

17. In a telephone system, the combination with lines, switches, charging apparatus for lines when calling, and means adapted to operate said apparatus when calling lines are connected by said switches to lines called for, of automatically operating means for disabling the apparatus operating means when calling lines are connected by said switches to certain of said lines.

18. In a telephone system, the combination with lines, an automatic connector, charging apparatus for lines when calling, and means adapted to operate said apparatus when calling lines are connected by said connector to lines called for, of automatically operating means for disabling the apparatus operating means when calling lines are connected by the said connector to certain of said lines.

19. In a telephone system, an automatic connector switch, lines of two kinds accessible to said switch, a calling line and means for extending it to said switch, a toll assessing device for said calling line, means for operating said switch to connect with any one of said first lines, means for operating said device if connection is established with a line of one kind, and means for preventing the operation of said device if connection is established with a line of the other kind.

20. In a telephone system, an automatic connector switch, lines of two kinds accessible to said switch, a calling line provided with a toll assessing device, means for extending the calling line to said switch, means for operating said switch to connect with any one of said first lines, and means for operating said device effective only when a particular kind of line is called.

21. In a telephone system, a calling line provided with a registering device, a connector switch, a plurality of other lines accessible to said switch, means for extending the calling line to said switch, means for operating said switch to connect with any one of said other lines, means for operating said register when the called subscriber answers, and means for rendering said last means ineffective when a particular line is called.

Signed by me at Norwood, county of Hamilton, State of Ohio, this 21st day of January, 1918.

FRANK NEWFORTH, JR.

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