US1443451A

US1443451A - Measured-service telephone system

Info

Publication number: US1443451A
Application number: US809542A
Authority: US
Inventors: Andersen Albert
Original assignee: Automatic Electric Co
Current assignee: Automatic Electric Co
Priority date: 1913-12-30
Filing date: 1913-12-30
Publication date: 1923-01-30
Anticipated expiration: 1940-01-30

Description

Jan. 30, 1923. 1,443,451.

A. ANDERSEN. MEASURED SERVICE TELEPHON sYsTEM.-

[ILED DEC. 30, 19H- MOT/V5655 MENTOR Z! a? v Patented Jan. 30, 1923.

UNITED STATES PATENT OFFICE.

ALBERT ANDERSEN, OF CHICAGO, ILLINOIS,,ASSIGNOE TO AUTOIYIATIC ELECTRIC COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

MEASURED-SERVICE TELEPHONE SYSTEM.

Application filed December 30, 1913.

To all whom it away concern:

Be it known that I, ALBERT ANDERSE'N, a citizen of the United- States of America, and resident of Chicago, Cook County, Illinois, have invented certain new and useful Improvements -in Measured-Service Telephone Systems, of which the following is a specification.

My invention relates to measured service telephone systems, and more particularly to systems in which the connection is established between two lines by automatic switches.

The object of my invention is to provide a measured service device which is 'controlled by a time mechanism whereby it will be operated at predetermined intervals of time. Heretoforafin systems where a measured service device is provided at the substation, this device has usually been operated upon the response of the called subscriber, but no means were provided to require further operation of the measured service de vice should a connection remain established more than a predetermined period of time.

The object of my invention is to provide means for preventing such connection remaining established more than a predetermined period of time without again operating the, meter.

By my invention I provide a time mechanism at the central ofilce which is started in operation when .the called subscriber resp0nds,-which time mechanism, at the end of a predetermined period, renders the talking circuit inoperative until the calling subscriber again operates his measured service device.

A further feature of my invention is the provision of a signal for notifying the calling subscriber that it is nearly time to again operate his measured service device. If this device is a coin controlled register, this signal gives the subscriber suflicient time -to have a coin ready to deposit in the coin-collecting device as soon as the time-controlled mechanism renders the talking circuit inoperative.

These and other objects ofmy invention will be more readily understood by reference to the accompanying drawings, in which I have illustrated one specific embodimentof my invention in connection with an automatic telephone system of a wellrknown type.

Serial N0. 809,542.

In the drawing I have shown a complete circuit connection between a calling substation A andv a called substation A.

The automatic system represented herein comprises the subscribers substation A together with the individual switch C- at the central office, a master switch D, a connector H, the called subscribers'line switch C" and the called substation A. It will be clearly understood by those versed in the art that so-c'alled selector switches may beinserted pulse transmitter or calling device which is represented herein by a pair of impulse springs 31 and 32 and an impulsefwheel 33. The impulse wheel 33 carries upon its peripheryimpulse teeth 34 and is secured to a shaft 35, to'which latter is also attached a dial (,not shown) provided with finger holes, through the medium of which the impulse wheel maybe rotated. As the impulse wheel is returned to normal position by a spring (not shown) after it has been rotated for any digit, each of the teeth 34 which passes the end of the spring 31 forcesv said spring out of engagement with the spring 32. The number of times these springs are'separated depends upon the digit called.

The coin-collecting device L associated with the substation A is of the same general springs' i, 5 and G are so arranged that when their contacts are closed, the transmitter'37 is shoirt-circuited and the receiver 25 is shunted by the resistance coil 11. I The lower end of the spring 4 carries a swinging arm 7 to. which is attached a 'small lug 13. If the polarized magnet is energized in one direc tion,*t he lower end of the arm 12, which is attached to the armature 3, will be tilted to the right and is carried behind the small lug 13. If the magnet then be energized 1n the opposite direction, the arm 12 engages the lug 13 and carries the arm 7 over with it, thus causing the springs 4, 5 and 6 tobe brought into engagement.

The subscribers switch C is of the general type of subscribers switch shown in British patent to R. 7. James No. 26,301 of 1906, being, however, of the particular type disclosed in said British Patent No. 1419 of 1910. This line switch comprises, among other details, a plunger (not shown) attached to'the end of a so-called plunger arm 39, which is controlled by the magnet 40. The magnet 40 comprises four windings, namely, a pull-down winding 43, a cut-off or holding winding 44, a line winding 46 and an auxiliarywinding 45. The core of the magnet 40 is so constructed that the magnetic circuit of the windings 43 and 44 is separate from that of the windings 45 and 46. The winding 43 operates both the plunger arm 39 and the cut-off armature 41,

while the Winding 44 is only strong enough to operate the cut-ofi' armature 41 and to hold the plunger arm 39 in its operated position. WVhen the plunger arm 39 is operated, the plunger is forced into a bank of contact springs, forcing the springs 49, 51, 53 and 55 into engagement with the springs 50, 52, 54 and '56, respectively. Although only one set of springs (49 to 56) 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 connector switch H.

Each trunk line is connected in multiple with the'corresponding springs of all the line switches of the group which is controlled by the, master switch D. The in dividual switch C is controlled by the subscriber through the mediumof the line relay 46,.as wilLb'e hereinafter more fully explained. v u

The master switch D is of the same general type as that disclosed in the abovementioned British Patent No. 26,301 of 1906,

being, however, of the particular type disclosed'in said British Patent No. 1419 of 1910. The function of the master switch, as is well known, is to maintainthe plungers of all the idle line switches in position to engage the terminal of an idle trunk line.

The connector switch H is of the same general t' eof connector switch disclosed in United gtates Letterslatent No. 815,17 6, granted March 13, 1906, to Keith, Erickson and Ericksoru'the circuits, however, being modified to adapt the switch'to operate in a system in which the central office apparatus is controlled by impulses delivered over thetwo sides of the line in series. The connector is provided with a shaft (not shown) carrying the wipers 14, 15 and 16 which is controlled by the vertical magnet 17 and the rotary magnet 18. The usual side switch comprising the wipers 19, 20, 21 and 22 is controlled by the private magnet 23 in the usual well-known manner. The magnet 24 is the usual release magnet. The line relay 36 is connected with the calling line through the reversing springs of the so-called back-bridge relay 37. The said back-bridge relay is the means'by which talking current is supplied to the called line. The ringing relay 38 is the means through which ringing current is applied to the called line.

The time-controlling device K associated with the connector H is controlled through the medium of a relay 67, which is connected in series with the windings of the backbridge relay 37 and is operated when the called subscriber answers. This time-controlling device K, as herein represented, consists of a ratchet wheel 68, to which is at tached a lever arm 69, and a motor magnet 70 which is controlled by a master clock M. The lever 69 is arranged to open the circuit of the controlling relay 67 after the said motor magnet has stepped the ratchet wheel shown), and also allows the springs 71 to again close the circuit of said magnet 67.

The called subscribers line switch C, substation A and coin-controlling device L'- are similar in all respects to the line controlling device L.

Having given a general description of the apparatus, in order to give a complete understanding of my invention I will now describe how the subscriber at substation A may establish connection with the subscriber at substation A. We will assume that the number of the called substation is 20. WVhen the calling subscriber removes his receiver preparatory to making a call.

the switch-hook rises, permitting the spring 95 to passout of engagement with the spring 97 and into contact vwith the spring 96, whereby the circuit of the ringer 29 and the condenser 30 is broken, and a bridge consisting of the substation transmitter, primary winding of the induction coil and the win-dings of the coin-collecting device is closed across the line conductors 98 and 99. The closure of this bridge across the line completes an energizing circuit through the line winding 46 of the switch thereby attracting the line armature 42. At thistime 'switchC, substation A and coin-controlling gizing, attracts the plunger arm 39 to force.

the plunger into the bank of contacts 49 to 56, inclusive. It also operates the cut-off armature 41, whereby the springs 101 and 104 are carried out of engagement with the springs 102 and 103, respectively, thus dis connecting the line' winding 46 'from the line. The armature 42 does not fallback immediately, however, owing to the fact that the windin 45 is still in series with the pull-down win i g arm 39 being attracted, the springs 108 and 109 arebrought together to short-circuit the auxiliary winding 45,-making same slightly slow acting. The armature 42, being slow to fall -back,iallo.ws sufficient time for a holdingcircuit to be closed in the switch ahead for the cut-01f or holding winding 44. The engagement of the: springs 49 and 55 with the springs 50 and 56, respectively, extends the subscribers line to the line relay 36 of the connector The line relay 36 of the connector H is thereupon energized, closing a circuit through the slow acting "relay 74. The relay 74, upon energizing,

closes the above-mentioned holding circuits through. the'cut-oif winding 44 of the line switchi- C. This circuit ,extends from ground G2 through the contact of springs 75, bani: springs 52 and 51 and the cut-off winding 44 to battery B, thence through battery B'to ground G. The winding 44, upon energizing, holds the armature 41 and the plunger arm 39 in their operated ositions after the circuit of the pull( own winding is broken by the falling back of the line armature 42. A guarding ground potential is supplied to the connector private bank contacts of the calling line as soon as the relay 74 is energized. This potential extends over the circuit just traced to the bank spring 51, thence over the trunk 115 to said private bank contact. The energization of the relay 74 also prepares a circuit for the vertical magnet 17 by bringing into engagement the springs 76 and 77 and opens the circuit of the release magnet, at the springs 77 and 78.

The calling subscriber now operates his dial for the first digit 2 of the called number, whereby the substation impulse springs 31 and 32 are operated twice momentarily,

* each time breaking the circuit of the connector line relay 36. Since the relay 74 is slow acting it does not deenergize during the momentary interruptions of its circuit by the relay 36 so that each time the latter 43.: Upon the plunger relay is denergized, a circuit isclosed extending from ground G through the contact of springs 80 and 7 9, springs 77 and 7 6, relay 82, vertical magnet 17 and the side switch wiper 19 (in first position) to battery B. The vertical magnet 17 receives two impulses over this circuit and operates to 113186 the switch wipers 14, 15 and 16 to a position opposite the second level'of bank contacts. The relay 82, which is included in series with the vertical magnet, remains energized during the entire time that impulses are being transmitted through it and oper ates to close the circuit of the private magnet 23. This circuit extends from ground G through the contact of springs 85 and 83 and the magnet 23 to battery B. I Aften the last impulse is delivered, the relay 82 opens the circuit of the private magnet: 23, which, upon deenergizing, permits the side switch to advance from first to second position.

The movement of the side switch wiper 19 in series with the. relay 82, whereby the shaft wipers are rotated onto the contacts of the desired line.- The said circuit extends from ground G through the contact of springs 80 and 79, springs 77 and 76, relay 82. springs 86, rotary magnet 18 and the side'switch wiper 19 (in second position) to hatteryuB. The relay 82 operates in re-v sponse to the impulses for this digit in the same manner as for the previous digit to cause the private magnet 23 to advance the side switch one more position, i. e., from second to third position. By the engagement of the side switch wipers 21 and 22 with their third-position contact points, and by the energization of the bridge cutmflt winding 87 of the switch C, the connection is completed with the called substation. The circuit for the briJdge-cut-ofi' winding extends from ground Gr through the side switch wiper 20 (in third position), private wiper 15, conductor 88 and the cut-off winding 87 to battery B. A guarding ground potential is supplied to the connector private bank contact 89 over the above-traced circuit which prevents .the called line from being seized by some other connector switch.

By the engagement of the side switch wiper 19 with its third-position. contact point, the.

erator R- across the called line to signal the called subscriber. The ringer relay is energized intermittently through the medium of the interrupter 90.

Upon the response of the called subscriber his line is provided with talking current through the windings of the back-bridge relay 37 and the controlling relay 67 in series. The relay 37, upon energizing, closes a circuit for the ringer cut-off relayextending from ground G through the side switch wiper .20 (in third position), contact of springs 114 and 113 and the said ringer cutoff relay 91 to battery B. The ringeigcut; off relay 91, upon energizing, interruptsthe circuit of the ringer relay 38 at the springs 91 and closes a locking circuit for itself through the springs 92 independent of the springs 113 and 114. The energization of the back-bridge relay 37 upon the response of the called subscriber, reverses the battery connections of t e line relay 36 with regard to battery B, w'ereby the direction of the current in the calling line is reversed. The

reversing of the current in the calling line causes the polarized relay of the coin-col lecting device at the substation A to attract its armature in the opposite directionthat is, toward the coil 9. vWhen the armature is Y attracted in this direction, it carries the arm 7 to the left, forcing thesprings 4, 5 and 6 into engagement. The engagement of said springs, as hereinbefore stated, short-circuits the transmitter 27 and shunts the secondary winding of the induction coil 28 with the resistance 11. The short-circuiting of the transmitter makes it impossible for the calling subscriber to talk to' the called subscriber through the transmitter. The shunting of the receiver does not prevent the calling subscriber from hearing the called subscriber answer, but is suflicient to prevent him from talking through his receiver. When the calling subscriber hears the called subscriber answer, hedeposits his coin in the coin chute (n ot shown) of the coin-collecting device L, thus causing the arm 7 to be released from the arm 12, thereby allowing the springs 4:, 5 and 6 to return to normal and the apparatus rendered operative for talking purposes. Upon the energization of the controlling relay 67 of the timecontrolling device K, the circuit of the motor magnet is closed at the springs 94 and this motor magnet is thus intermittently operated by means of the clock mechanism M. At the same time the operation of this relay 67 permits the holding pawl 93 to drop into engagement with the ratchet 68. .As this arm 69 is rotated, it first closes the springs 100, which causes a signal to be transmitted to the calling subscriber. The path of this signaling current is as .fol-lows: from the conductor 101 through the springs 100, over the calling line conductors'98 and 99 and through the substation A, thence back through battery B. As'the arm 69 continues to rotate, it opens the springs/71, thus opening the circuit of the back-bridge relay 37 and the controlling relay 67. The relay 37, upon deenergizing, causes the battery to be reversed back to normal on the calling line, causing the arm 12 to be again carried back of the lug 13. The relay 67, upon deenergizing, allows the time-controlling device K to be restored to normal, thus againclosing the circuit ofthe back-bridge relay 37 and the controlling relay 67. The said back-bridge relay 37, upon energizing, again reverses the current in the calling line, thus rendering the talking circuit inoperative, the same as stated above, and the calling subscriber must again deposit another coin before the conversation can again be resumed. The above result occurs at predetermined intervals of time, thus making it necessary for the calling subscriber to deposit coins at regular intervals of time.

The purpose of the signal operated by the springs 100 is to advise the calling subscriber that if he wishes to continue conversation he must soon again deposit another coin inthe coin-collecting device and thus give him an opportunity to have his coin ready to deposit as soon as the talking circuit is again rendered'inoperativ'e by the separation of the springs 71.

After the conversation is completed, the connection is released by the hanging up of the receiver at the calling substation in the usual and well-known manner.

From the foregoing it will be. seen that the calling subscriber s telephone set is rendered inoperative when the called subscriber answers. The calling subscriber can listen and hear the response of the called subscriber, but cannot use his transmitter until he has deposited a coin. Furthermore, it will be seen that I hai e devised a very efii cient means for placing a time limit upon the length of time that a conversation may be carried on without depositing an extra coin. I obtain the above result by rendering the calling subscribers substation inoperative for talking purposes after predetermined intervals of time, thus making it necessary to deposit an extra coin before the conversation may be further continued.

WhileI have illustrated my invention in connection with one particular type of automat-ic system, it will, of course, be understood that it .is capable of use with many other forms of systems, and is equally as well adapted for use in connection with semiautomatic systems, i. e., systems-in which a manual link circuit is employed in combination with automatic means for establishing a connection between two subscribers lines.

What I claim as.my invention is 1. In a telephone system, a plurality'of subscribers lines, means including automatic selecting and connecting switches for establishing a talking circuit between two of said lines, means controlled by the response of the called subscriber for reversing the current in the calling line, means controlled by said reversal of current for rendering said talking circuit inoperative, a measured service device for again rendering said talking circuit operative, a time-controlled mechanism, means controlled by the response of the called subscriber for starting said mecha nism in operation, means controlled by said mechanism for momentarily reversing the current in the calling line at predetern'iined intervals of time to again render said talking circuit inoperative, and means controlled by subsequent operations of said measured service device for again rendering said talking circuit operative.

2. In a telephone system, a plurality of subscribers lines, means including automatic selecting and connecting switches for establishing a talking circuit between two of said lines, means controlled by the response of the called subscriber for reversing the current in the calling line, means controlled by said reversal of current for rendering said talking circuit inoperative. a coin-collecting (18V1C6, means controlled by the deposting of a coin in said device for again rendering said talking circuit operative, a time-controlled mechanism, means controlled by the response of the called subscriber for starting said mechanism in operation, means controlled by said mechanism for momentarily reversing the current in the calling line at predetermined intervals of time to again render said talking circuit inoperative, and means controlled by the depositing of subsequent coins in said coin-collecting device for rendering said circuit operative.

3. In a telephone system, a plurality of subscribers lines, means for establishing a talking circuit between two of said lines, a time-controlled mechanism, means controlled by the response of the called subscriber for starting said mechanism in operation, means controlled by said mechanism for rendering said talking circuit inoperative at predetermined intervals of time and for giving the calling subscriber a signal before the talking circuit is rendered inoperative. and a measured service device on the calling line for-again rendering said circuit operative.

4. In a telephone system, a plurality of.

subscribers lines, means for establishing a talking circuit between two of said lines. a time-controlled mechanism, means controlled by'the response of the called subscriber for starting said mechanism in op"-- eration, means controlled by said mechanism. for rendering said talking circuit inoperative at 'iredetermined intervals of time and for giving the calling subscriber a signal before the talking circuit is rendered inoperative, a izoiii collecting device, and means controlled by the depositing of a coin in said device for again rendering said talking circuit operative. I

5. In a telephone system, a plurality of subscribers lines, means including automatic selecting and connecting switches for establishing a talking circuit between two of said lines, a time-controlled mechanism, means controlled bythe response of the called subscriber for starting said mechanism in operation, means controlled by said mechanism for rendering said talking circuit inoperative at predetermined intervals of time and for giving the calling subscriber a signal before the talking circuit is rendered inoperative, a coin-collecting device, and means controlled by the depositing of a coin in said device for again rendering said talking circuit operative' 6. In a telephone system, a plurality of subscribers lines, means for establishing a talking circuit between two of said lines, a time-controlled mechanism, means controlled by the response of the called subscriber for starting said mechanism in op eration. means controlled by said mechanism for rendering said talking circuit inoperative at predetermined intervals of time and for giving the calling subscriber a signal over said line before the talking circuit is rendered inoperative, and a measured service device. on the calling line for again renderin said circuit operative.

In a telephone system,a plurality of subscribers lines, means for establishing a talking circuit between two of said lines, a time-controlled mechanism, means controlled by the response of the. called subscriber for starting said mechanism in operation, electromagnetic means controlled by said mechanism for rendering said talking.

circuit inoperative at predetermined intervals of time and for giving the calling subscriber a signal before the talking circuit is rendered inoperative, and a measured service device on the calling line for again rendering said circuit operative.

8. In a telephone system, a plurality of subscribers lines, means for establishing a talking circuit between two of said lines, a time-controlled mechanism, means controlled by the response of the called subscriber for starting said mechanism in operation. means controlled by said mechanism for rendering said talking circuit inoperative at predetermined intervals of time and for giving the calling subscriber a signal over said line before the talking circuit is rendered inoperative, a coin-collecting device, and means controlled by the depositing of a coin in said device for again rendering said talking circuit operative.

9. In a telephone system, a plurality of subscribers lines, means forestablishing a talking circuitbetween two of said lines, a time-controlled mechanism, 1 means controlled by the response of thecalled subscriber for starting said mechanism in operation. electromagneticmeans controlled said mechanism for renderin said talking circuit inoperative at predetermined intervals of time and for giving the calling subscriber a signal before the talking circuit is rendered inoperative. a coin-collecting device, and means controlled by the depositing ot' a coin in said device for again rendering said talking circiiit operative. p

10. In a telephone system, a plurality of subscribers lines, means including automatic selecting and connecting switches for estab lisliinga talking circuit between two of said lines. a time-controlled mechanism, meanscontrolled by the response of the called subscriber for starting said mechanism in operation, means controlledby said mechanism for rendering said talking circuit inoperative at predetermined intervals of time and for giving the calling subscriber a signal over said line before the talking circuit isrendered inoperative, a coin-collecting de vice, and means controlled by the depositing of a coin in said device for again rendering said talking circuitinoperative.

11. In a telephone system, a plurality ot subscribers lines, means including automatic selecting and connecting switches for establishing a talking circuit between two of said lines. a time-controlled mechanism, means controlled by the response of the called subscriber for starting said mechanism in operation, electromagnetic means controlled by said mechanism for rendering said talking circuit inoperative at predetermined intervals of time and for giving the calling subscriber a signal before the talking circuit is rendered inoperative, a coin-collecting device, and means controlled by the depositing of a coin in said device for again rendering said talking circuit operative.

12. In a telephone system, a calling and it called line, means including an automatic progressively movable switch for connecting said lines, means for assessing a charge to the calling subscriber at the beginningof the conversation, means for repeating the charge at intervals thereafter, and an audible signal to notify the calling subscriber each time an additional charge is assessed.

13. In a telephone system, a calling and a called line, means including an automatic progressively movable switch for connecting said lines, means for collecting a coin from the calling subscriber at the beginning of the conversation, automatic means for requiring the collection of additional coins at intervals thereafter, and an audible signal to notify the calling subscriber each time an additional coin is required.

11., In a telephone system, a calling and a called line, meansincludingan automatic progressively movable switch for connecting said lines, automatic means for requiring the calling subscriber to pay before beginning conversation, automatic ineans for requiring another payment if the conversation extends beyond a predetermined time limit. and means for notifying the calling subscriber when the additional payment is required. v v I 15. In a telephone system. a calling and a called .line, means including an automatic progressively movable switch for connecting said lines, automatic means for requiring the calling subscriber to pay before beginning conversation, automatic means for requiring another payment it the conversation extends beyond a predetermined time limit, and an audible signal to warn the calling subscriber that the predetermined'time has-elapsed; a

16. In a telephone system, a calling and a called line, means including an automatic progressively movable switch for connecting said lines. a coin collecting device for the calling subscriber, means for requiring the calling subscriber to deposit a coin. in said device before beginning conversation, an automatic time controlled mechanism for interrupting the conversation at regular intervals thereafter to require the depositof additional coins. and means for warning the calling subscriber before the conversation is interrupted.

17, In a telephone system. a calling and a called line, means including an automatic progressively movable switch for connecting said lines, means for collecting a coin from the calling subscriberbefore the talking circuit can be established. automatic means for disabling the talking circuit after a predetermined time to require the collection of another coin, a device for producing anvaudible distinctive tone. and means for connecting said device with the calling line to notify the calling subscriber that an additional coin is required.

18. In a telephonesystem, a calling and it called line. means including an automatic progressively movable switch for connecting said lines. a coin collecting device for the calling subscriber, means for requiring the calling subscriber to deposit a coin in said device before beginning conversation, an automatic mechanism for interrupting the conversation after a predetermined time to require the deposit of an additional coin,.

a device for producing an audible distinc tive tone, and means for connecting said device With the calling line to notify the calling subscriber that an additional coin is required. I i

19. In a telephone system, a. calling and a called line, means for connecting said lines. a reverse current controlled device for rendering the calling telephone inoperative for talking purposes. means comprising a coin collecting device for restoring the calling telephone to operative condition. a battery for supplying talking current. means for reversing the current flow in the calling line to require the deposit of a coin before conversation can begin. and means for momentarily reversing the current flow in the calling line again after a predetermined time to require the deposit of another coin.

20. In a telephone system. a calling and :1 called line. means for connecting said lines. mechanism for rendering the telephone on the calling line inoperative for talking purposes. a coin collecting device, means controlled by the deposit of a coin therein for restoring the calling telephone to operative condition. means for operating said mechanism to require the deposit of a coin before conversation can begin. means for reoperating said mechanism after a predetermined time to require the deposit of an additional coin. and means for notifying the calling subscriber when the additional coin is to be deposited.

21. In a telephone system. a calling and a called line. means for connecting said lines. mechanism for rendering the telephone on the alling line inoperative for talking purposes. a coin collecting device. means controlled by-the deposit of a coin therein for restoring the calling telephone to operative condition. means for operating said mechanism to require the deposit of a coin before conversation can begin. means for reoperating said mechanism at regular intervals thereafter to require the deposit of additional coins. and means for notifying the calling subscriber when the additional coin is to be deposited.

22. In a telephone system. a calling and a called line. means for connecting said lines. a reverse current controlled device for rendering the calling telephone inoperative for talking purposes. means comprising a coin collecting device for restoring the calling telephone to operative condition, a battery for supplying talking current. means for reversing the current flow in the calling line to require the deposit of a coin before conversation can begin. means for momentarily reversing the current flow in the calling line again after a predetermined time to require the deposit of another coin. and means for notifying the calling subscriber when an additional coin is to be dermsited.

23. In a telephone system, a calling and it called line. means for connecting said lines. n'iechanlsm for rendering the telephone on the calling line inoperative for talking purposes. a coin collecting device.-

means controlled by the deposit of a coin therein for restoring the calling telephone to operative condition. means for operating said mechanism to require the deposit of a coin before conversationcan begin. means for reoperating said mechanism after a predetermined time to require the deposit ofan additional coin. a device for producing an audible tone. and means for connecting said device with the calling line whenever an additional coin is required to notify the calling subscriber.

, 2-l. In-a telephone system. a calling and a called line. means for connecting said lines. mechanism for rendering the telephone on the calling line inoperative for talking purposes. a coin collecting device. means controlled by the deposit of a coin therein for restoring the calling telephone to operative condition. means fm-operating said mechanisnrto requirethe deposit of a coin before conversation can begin. means for reoperating said mechanism at regular intervals thereafter to require the deposit of additional coins. a device for producing an audible tone. and means for connecting said device with the calling line Whenever an additional coin is required to notify the calling subscriber.

25. In a telephone system. a calling and a called line. means for connecting said lines, a reverse currentcontrolled device for rendering the calling telephone inoperative for talking purposes. means comprising a coin collecting device for restoring the calling telephone to operative condition. a battery for supplying talking current. means for reversing the current flow in the calling line to require. the deposit of a coin before conversation can begin. means for momentarily reversing the. current flow in the callline again after a predetermined time to require the deposit of another coin. a device for producing an audible tone. and means for connecting said device with the calling line whenever an additional coin is required to notify the calling subscriber.

26. In a telephone system. a calling and a called line. means including an automatic progressively movable switch for connecting said lines, mechanism for rendering the telephone on the calling line inoperative for talking purposes, a coin collecting device. means controlled by the deposit of a coin therein for restoring the calling telephone to operative condition, means for operating said mechanism to require the deposit of a coin before conversation can begin, means for reoperating said mechanism at regular intervals thereafter to require the deposit of additional coins, and means for notifying the calling subscriber when the additional coin is to be deposited.

27. In a telephone system. a calling and a called line, means including an automatic progressively movable switch for connecting said lines, a reverse current controlled clevice for rendering the calling telephone inoperative for talking purposes, means comprising a coin collecting device for restoring the calling telephone to operative condition, a battery for supplying talking current, means for reversing the current flow in the calling line to require'the deposit of a coin before conversation can begin, means for momentarily reversing the current flow in the calling line again after a predetermined time to require the deposit of another coin, and means for notifying the calling subscriber when an additional coin is to be deposited.

28. In a telephone system, a calling and a called line, means including an automatic progressively movable switch for connecting said lines, mechanism for rendering the telephone on the calling line inoperative for talking purposes, a coin collecting device, means controlled by the deposit of a coin therein for restoring the calling telephone to operative condition, means for operating said mechanism to require the deposit of a coin before conversation can begin, means for reoperating said mechanism after a predetermlned time to require the deposit of an additional coin, a device for producing an audible tone, and means for connectingsaid device with the calling line whenever an additional coin is required to notify the calling subscriber.

29. In a telephone system, a calling and a called line, automatic switches controlled over the two sides of the calling line in series for connecting said lines, a talking transmitter at the calling station, a relay at the calling station connected in the line in series with said transmitter, means at the exchange for operating said relay over the line to render the calling station inoperative for talking purposes, a measured service device operable by the calling subscriber to render the calling station operative, and a device at the exchange operating periodically to reoperate said relay over the line circuit in order to require the calling subscriber to reo erate said measured service device.

30. n a telephone system, a calling and a called line, means including an automatic progressively movable. switch for connecting said lines, a closed control circuit for said switch including the two conductors of the calling line and a battery at the exchange connected in series, means for reversing the connections of the line conductors with respect to-the battery after the connection is established, means responsive to such reversal for requiring the calling subscriber to pay before beginning conversation, and automatic means for requiring an additional payment at the end of a predetermined time interval thereafter.

31. In a telephone system, a calling and a called line, means including an automatic progressively movable switch for connecting said lines, a closed control circuit for said switch including the two conductors of the calling line and a battery at the exchange connected in series, means for reversing the connections of the line conductors with respect to the battery after the connection is selecting and connecting switches for estab- 1 lishing a talking circuit between two of said lines, means controlled by the response of the called subscriber for reversin the cur-. rent in both conductors of the ca ling line a polar relay responsive to said reversal oi current for rendering said talking circuit inoperative, a coin collecting device, means controlled by the depositing of a coin in said device for again rendering said talking circuit operative, time controlled means for thereafter rendering said talking circuit inoperative at predetermined time intervals, and means controlled by the depositing of subsequent coins in said coin collecting device for rendering said talking circuit operative.

33. In a telephone system, a calling and a called line, means including a subscriber controlled progressively movable switchfor connecting said lines, a closed control circuit for said switch including the two conductors of the calling line and a battery at the exchange connected in series, a talking transmitter at the station on the calling line supplied with current from said battery over said conductors, reversing mechanism in the battery feed connections at the exchange, a timing device for operating said mechanism periodically during conversation, and means responsive to reversals of current in the calling line to assess charges against the calling subscriber.

34:. In a telephone system, a calling and a called line, means including a subscriber controlled progressively movable switch for connecting said lines, a closed control circuit for said switch including a talking transmitter at the station on the calling line, a line relay in said switch, and the two conductors of the calling line in series, a battery included in said circuit, mechanism for reversing the direction of current flow from said battery in said circuit, a timing device for operating said mechanism periodically during conversation, and a measured service 1 device including a magnet in the said control circuit sensitive to current reversalsfor assessing charges against the calling subscriber. 35. In a telephone system, a calling and a called line, an automatic progressively movable switch, a line relay in said switch, a closed control circuit for said relay including a battery at the exchange and the two sides of the calling line in series, means at the station on the calling line for producing series of interruptions in said circuit to operate said line relay, whereby the said switch is actuated to effect connection between said lines, mechanism at the exchange for altering the connections between the conductors of the calling line and said battery to produce current changes in the line, a timing device versation and sensitive to said current changes to assess charges against the calling subscriber.

Signed by me at Chicago, Cook County, Illinois, this 22nd day of December, 1913. ALBERT ANDERSEN. Witnesses:

M. R. MORGAN, G. YANOOHOWSKI.