US1650409A - Automatic telephone system - Google Patents

Description

Nov. 22, 1927.

B. D. WILLIS AUTOMATIC TELEPHONE SYSTEM 2 eats-Sheet l Original Filed Jan. 28. 1920 Nov. 22, 1927. 1,650,409

B. D. WILLIS AUTOL iATIC TELEPHONE SYSTEM Original Filed Jan. 28, 1920 2 Sheets-Sheet 2 Ififin'ff Bernard D. M11115.

Patented Nov. 22, 1927.

UNITED STATES PATENT OFFICE.

BERNARD D. WILLIS, OF OAK PARK, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNHEN TS, TO AUTOMATIC ELECTRIC Ill'C, OF CHICAGO, ILLINOIS, A CORPORATION OF DELA- WARE.

Application filed January as, 1920, Serial No. 354,814. Renewed m 21, 1925.

My invention relates in general to automatic telephone systems, but more particularly to measured service automatic telephone systems; and has for its principal object the provision of means for assessing charges in large systems comprising a number of more or less widely separated exchanges, the charge assessing means belng capable of automatic operatlon in any g ven case to assess a variable charge, dependlng, first, on the exchange with which the connection is established, and second, on the duration of the conversation.

A measured service system arranged to antomatically charge variable amounts for connections to different exchanges is commonly known as a zone metering system. I do not claim to be the" first inventor of such a system, and refer to the U. S. patent to Powell, #1,303,958, which shows a representative system of this class. I have, however, devised certain improvements; and provide in a systemv of this general character, not only means for assessing a variable charge, which I call the initial charge. but also means for assessing either a fixed unit charge or a variable charge at variable time intervals during the conversation, thus providing a system more adaptable to the various conditions confronting operating telephone companies.

The foregoing and other useful objects are accomplished by means which will be fully described and explained hereinafter, reference being had to the accompanying drawings, comprising Figs. 1 and 2, which are circuit diagrams of so much of the exchange equipmentas is necessary for an understanding of the invention.

Referring to the drawings, I have shown therein only a portion of the apparatus required to complete a connection between a calling and a called subscriber: but in view of the well known character of the apparatus, and of the fact that telephone systems of this character are now wellunderstood, it is believed that sufficient has been shown to enable the invention to be readily understood.

In Fig. 1, the substation indicated by reference character A, is an ordinary automatic substation which comprises the usual talking equipment and ringer, and also a calling device S, through the medium of which the subscriber controls the central ofiice switches.

The line conductors 11 and 12 extend to the exchange where they terminate in the rotary line switch 0, which may be briefly described as a line switch whose wipers have a rotary movement in a forward direction only, and which have no normal position. That is, when the switch is released the wipers do not return to normal but remain on the set of contacts last used. A plurality of .these individual ,line switches may be given access to a grbup of trunk lines extending to first selector switches, and one of the trunk lines to which the line switch C has access is shown in the drawing as extending to the first selector D. The selector D is a vertical and rotary switch of familiar construction, and together with a plurality of similar selectors, has access to a plurality of groups of trunk lines.

a s before mentioned, the system which is being described herein, contemplates a plurality of exchanges and the different groups of trunk lines to which the first selectors have access will ordinarily extend to different exchanges, although one or more groups may of course go 'to the same exchange, while ordinarily at least one group will be reserved for local trafiic. In the drawing I have shown two sets of contacts in the first and second levels of the selector D, but it is understood that the selectors will have ten levels corresponding to ten different groups of trunk lines. One of the trunk lines terminating in the first level is the trunk line comprising conductors 76, 77 and 78 which extends to the repeater B (Fig. 2) and then continues by way of conductors 200 and 201, to a distant exchange, where the conductors 200 and 201 terminate in the line, relay of a second selector switch.

The repeater R comprises the group of relays shown in the upper half of Fig. 2, and has the usual functions of a repeater in a two wireautomatic telephone system. As-'; sociated with each repeater there is provided an auxiliary switch, which in the case of the repeater R is indicated by the reference character P. The auxiliary switch P is a rotary step by step switch of simple construction, having two semi-circular rows of bank contacts which are adapted to be engaged by the wipers 153 and 154, respectively. The shaft carrying the said wipers is given a step by step rotary movement by means of the rotary magnet 150. Backward movement of the shaft is prevented by a pawl in the usual manner, and the release of the switch is brought about by the withdrawal of the said pawl under control of the release magnet 152. The function of the auxiliary switch P is to actuatethc meter of each calling substation which establishes a connection by way of the repeater R in accordance with the proper charge for the connection.

Having described in a general way the apparatus shown herein, I will now describe the operation briefly during the establishment of the connection, with special reference to the operation of the auxiliary switch P in controlling the meter of the calling subscriber, after which a more general explanation will be given of the difierent methods of connecting the bank contacts of the auxiliary switches associated with the different trunk groups in order to take care of difi'erenttoll charges. It will be assumed that the subscriber at substation A desires to connect with a subscriber in the exchange to which the trunk line comprising conductors 200 and 201 extends. When the receiver is removed at substation A, a circuit is completed over the line conductors 11 and 12 for the line relay 14 of the line switch C. Upon energizing, the line relay 14 completes av circuit extending through the switching relay 13 and the stepping magnet 21 in series to battery. This circuit is completed at armature 20 of the line relay, and at armature 19 the test wiper 32 is connected to the above circuit at a point midway between the switching relay and said stepping magnet. The operation now depends upon whether the test contact with which the test wiper 32 is in engagement is busy or is not busy. If this test contact is busy it will have a ground potential upon it, the switching relay 13 will be short circuited, and the stepping magnet 21, which interrupts its own circuit, will be operated in the manner of a buzzer to advance the switch wipers 30 to 33, inclusive, step by step in search of an idle trunk line. This operation will continue as long as the test wiper 32 continues to engage grounded or busy testcontacts. However, we may assume that in the present case. when the call is initiated, the selector D is idle, and a test contact 36 therefore is not grounded. In these circumstances, when the line relay 14 is energized the switching relay 13 is energized immediately afterwards, with the result that the line conductors 11 and 12 are disconnected from the line relay 14 and from ground, respectively, and are extended by way of armatures 15 and 18 and their working contacts, line wipers 30 and 33, trunk conductors 38 and 40, and armatures 60 and 63 and than resting contacts to the upper and lower -Windings respectively, of the .line relay 50 of the selector D. I

Upon the extension of the callingvline as above described, the line relay 50 will be energized over the line circuit and will close a circuit for the slow acting release relay 51. Upon energizing, relay 51 prepares the selector D for vertical operation in the usual g/manner, and also completes a holding circuit extending back to the line switch C over the following path: ground at G working contact of armature 64 and the said armature, conductor 39, test contact 36, test wiper 32, armature 17 and its working contact, winding of switching relay 13, and the winding of the stepping magnet 21' to battery. It is understood that the above circuit is established before the slow acting relay 14 has had time to deenergize. It will be observed that there is a branch circuit' extending from the grounded conductor 39 by way of the resistance 43, and the winding of relay 42 to battery. Relay 42 is a marginal relay and is not energized at the present time.

The calling subscriber may now operate his calling device in accordance with the first digit of the desired number. A series of interruptions is thereby produced in the circuit of line relay 50, causing a corresponding se-' ries of deenergizations of the said relay, which at each deenergization sends a current impulse through the slow acting relay 52 and the vertical magnet 56 to battery. By the operation of the vertical magnet 56 the switch shaft is raised step by step until the wipers to 72, inclusive, stand opposite the bank level in which are terminated the trunk lines leading to the desired exchange. In the present case. the wipers will be raised opposite the level containing bankcontacts 73 to 75, inclusive. The slow acting relay 52 is energized in serieswith the vertical magnet, retaining its armature attracted throughout the vertical movement oft the switch, and upon the closure of off normal contact springs-58, completes a circuit for the stepping relay 53. Upon energizing, relay 53 establishes a locking circuit for itself at its upper armature, and at the lower armature prepares a circuit for the rotary magnet 54. At the end of the vertical movement of the switch the slow acting relay 52 is deenergized and closes the circuit of the rotary magnet, which is thereupon energized to ro tate the switch wipers into engagement with the first set of bank contacts in the level opposite which they were raised. The rotary, magnet also breaks the locking circuit of the stepping relay 53, which accordingly is deenergized to break the circuit of the rotary magnet, which thereupon deenergizes also, and again closes its interrupter contact. The operation now depends upon whether the test contact with which the test wiper 71 is in engagement is busy or is not busy. If this test contact is busy it will have a ground potential upon it, and the stepping relay 53 will again be energized over a circuit which extends from the grounded test contact by way of the test wiper 71, armature 61 and its resting contact. interrupter contact of the rotary magnet 51, off normal springs 58. and the winding of the stepping relay 53 to battery. The stepping relay will therefore again close the circuit of the rotary magnet. which will operate to advance the switch wipers into engagement with the next set of bank contacts. This operation in which the stepping relay and the rotary magnet 54 are alternately energized and deenergized takes place very rapidly, and will continue as long-as the test wiper 71 continues to engage busy or grounded test contacts. In the present case it will be assumed that the trunk line shown in the drawing is the first idle trunk line, and when, therefore. the test wiper 71 arrives at test contact 74 and the rotary magnet 54 is deenergized, the stepping relay 53 will not again be energized; but the switching relay 55, which heretofore has been short circuited, will be energized by current flow over the following path: grounded conductor 39, winding of switching relay 55, interrupter contact of the magnet 54. off normal springs 58, and the winding of the stepping relay 53 to battery. Owing to the high resistance of the switching relay the stepping relay 53 is not energized by current flow in the above circuit. Upon energizing, relay 55 disconnects the trunk conductors 38 and 40 from the windings of the line relay 50 and extends them by way of armatures and 63 and their working contacts. line wipers and 72, bank contacts 73 and 75, conductors 76 and 78, and normally closed contacts of reversmg relay 100,'to the upper and lower windings, respectively, of the double wound line relay 101 of the repeater R The line relay 101 is accordingly energized over the line circuit and upon attracting its armature 110 completes a circuit for the slow acting release relay 102. Upon energizing. relay 102 closes a circuit through the polarizing winding of the electro-polarized relay 104 at its armature 113, and at its armature 114 completes a holding circuit extending back to the selector D over the following path: ground at G normally closed contact springs controlled by-armature 123, working contact of armature 114' and the said ari'i'iature. conductor 77. test contact 74. test wiper 71, and armature 01. and its working contact to'the conductor 30. where it joins the previously described holding circuit extending back to the line switch C. The circuit just described serves to maintain relays 55 and 13 energized throughout hand winding of impedance coil 10?, and armature 111 of the now energized line relay 101 and its working contact to the trunlcconduct-0r 201. By the closure of the bridge just described a circuit is completed for the line relay of the second selector in the distant exchange (not shown) in the usual manner. and the said line relay and its associated slow acting release relay are accordingly energized and the distant selector is prepared for operation.

The calling subscriber may now operate his calling device in accordance with the next digit in the desired number, thereby causing a series of deenergizations of the line relay 101 of the repeater R, which at each deenergization opens the bridge across the trunk conductors 200 and 201 and thereby interrupts the circuit of the line relay of the distant selector switch. The said selector is accordingly operated in the well known manner to raise its wipers in accordance with the digit called, after which the said wipers are rotated and connection is established with an idle trunk line which may extend either to another selector switch or to a connector switch. depending upon the size of the exchange. At the repeater It, while the line relay 101 is deenergizing intermittently to repeat impulses to the second selector switch in the distant exchange, it sends an impulse at each deenergization to slow acting relay 108. This relay is energized upon the first impulse and maintained energized throughout the series of impulses to complete the bridge across trunk eon-- ductor 200 and 201 over a non-inductive path which may be traced from trunk conductor 200 by way of armature 115 and its working contact. armature 11R and its working contact, and armature 111 and its working contact to the trunk conductor 201. This operation, by removing the windings of relay 104 and impedance coil 107 from the circuit, produces a better control circuit for operating the series of switches in the distant exchange.

The calling subscriber may now call the remaining digits in the desired number, with the result that additional series of interruptions are produced in the circuit of the line relay 101. which operates as before to repeat the interruptions, and thereby brings about the operation of the remaining switch or switches in the distant exchange which are required to complete the comu-iction with the called subscribers line. The bell at the ly, and when the called subscriber removes his receiver responsive thereto, the ringing equipment is automatically cut off, and the called station is supplied with talking battery through the windings of the back bridge relay of the connector in the usual manner. As is customary, this back bridge relay is provided with contact springs which reverse the connections'of the incoming line conductors, thereby reversing the direction of current flow over conductors 200 and 201, and through the lower winding of the electro-polarized relay 104 at the repeater B. As a result, the relay 104, which heretofore has remained inoperative, is operated, and at its armature 118 closes circuits through relays 100 and 105. Relay 100 is a reversing relay which reverses the direction of current flow in the incoming trunk conductors 76 and 78, for no useful purpose however, in connection with the apparatus shown; but inasmuch as it is a standard operation and is of utility under certain circumstances which it will not be necessary to mention the circuits have been shown in this manner. Relay 100 also connects an additional pair of condensers, and includes the left hand winding of the impedance coil 107 in series with the right hand winding, with the object of increasing theefliciency of the talking circuit. The complete connection has now been established and the subscribers may converse as desired.

The manner in which the meter M associated with the calling subscribers line is operated will now be considered. When the relay 105 is energized by the closure of its circuit at armature 118 of relay 104, as previously mentioned, the said relay establishes a locking circuit for itself and its armature 120, and at its armature 121 closes a circuit over conductors 160 and 161 for the stepping magnet 150 of the auxiliary switch as will appear hereinafter, other time inter vals may be used to advantage in.certain cases. To continue with the explanation, when the circuit of the stepping magnet 150 is closed by relay 105 the said stepping magnet will be operated every three seconds to rotate the wipers 153 and 154 step by step over the bank contacts associated therewith. When wiper 154 arrives at bank contact 164, and the stepping magnet 150 deenergizes, a circuit is completed for the relay 106 of the repeater R'as follows: ground at G, contact springs controlled by the stepping magnet 150, wiper 154, bank contact 164, conductor 165, resting contact of armature 157 and the said armature, conductor 159, and the winding of relay 106 to battery. Upon attracting its armature 123, relay 106 alters the previously described holding rircuit extending back over conductor 77 to selector D and line switch G to the extent that the said holding circuit is completed from ground G by way of battery B and resistance X instead of from ground G. By this operation the battery B is connected in series with the exchange battery and causes an increased flow of currentthrough the marginal relay 42. As previously stated this relay 42 is marginally adjusted and has remained inoperative up to the present, but is now sufliciently energized to enable it to attract its armature 44, thereby closing a circuit which extends from ground by way of the said armature 44, bank contact 35, wiper 31, working contact of armature 16 and the said armature, and the, winding of the operating magnet of meter M to battery. The meter is therefore operated to register one unit charge against the calling subscriber. Relays 106 and 42 are deenergized and the circuit of the meter magnet is broken when the wiper 154 is stepped off from bank contact 164 and onto the next bank contact, but when the wiper 154 arrives at bank contact 166 the circuit of relay 106 is again closed by way of conductor 168 and armature 155 and its resting contact, so that the meter M Will be operated to register another unit charge. The same thing occurs when wiper 154 arrives at bank contact 167, and it will be seen therefore that within 15 seconds the meter of the calling subscriber will be operated three times to register three unit charges. Nothing further occurs until the wiper 154 arrives at contact 170, when a circuit will be closed by way of the wiper 154, bank contact 17 0, conductor 169, normally closed contact springs controlled by armature 156. and the winding of relay 151 to battery. Upon energizing, relay 151 establishes a locking circuit for itself at armature 156 and at armature 155 disconnects conductor 168 from conductor 165. After the expiration of one minute, wiper 154 will arrive at contact 172, which is connected with bank contact 164, and the circuit of relay 106 will again be closed and the meter M will again be operated to register another unit charge. This operation is repeated when the wiper 154 arrives at bank contact 173, which will occur upon the expiration of another minute. When the wiper 154 arrives atthe last contact in its bank, which it will do one minute later, wiper 153 will engage bank contact 174, thereby closing a circuit by way of 'ill the said wiper 153, which is grounded, bank contact 174, conductor 175, and the Winding of the release magnet 152 to battery. Upon energizing, the release magnet 152 opens the connection between conductors 165 and 159 at its armature 157, and also releases the switch in any well known manner, Whereupon the wipers 153 and 15 are at once restored to normal position. The release magnet 152 is maintained energized by the circuit through the bank contacts engaged by the wiper 153 until the wipers are restored to normal. The release of the switch P is completed within the three second interval, and when the stepping magnet 150 receives another impulse, the wipers are again started on their rotation over their associated bank contacts, and the meter M will be operated once each minute as long as the subscribers continue to converse, the switch P being released as many times as is necessary. It will be noticed that during the second rotation of the switch P, and all subsequent rotations, the meter will not be operated when the wiper 154 passes bank contacts 166 and 167, due to the fact that the relay 151 was energized and locked up on the first rotation of the switch.

When the conversation is finished both subscribers will hang up their receivers. When the receiver is replaced at substation A, all the switches involved in the connection are released and restored to normal, the release being initiated by the denergization of the line relay 101 of the repeater R. Upon denergizing, relay 101 opens the bridge across the trunk conductors 200 and 201 which causes the switches in the distant exchange to release in the usual manner. The slow acting release relay 102 is also deenergized following the deenergization of the line relay 101, and breaks the holding circuit extending back over conductor 77 to the selector D and line switch C. As a result, relays 55 and 13 are deenergized and the said switches are restored to normal in the usual and well understood manner. The auxiliary switch P, which is associated with the repeater E is also released upon the deenergization of the release relay 102 by the closure of the following circuit: grounded armature 110 and its resting contact, armature 112 and its resting contact, working contact of armature 122 and the said armature, conductor 162, and the winding of the release magnet .152 to battery. This circuit is broken by the deenergization of relay- 105 an instant after it is completed, but the complete release of the auxiliary switch is insured by the circuit over wiper 153 which was previously'described, The apparatus has now been all completely restored to normal position and is ready for use in another connection.

I will now describe briefly how the auxilcorrespond to a different exchange, one of which may be the local exchange, or the exchange to which the substation A is connected, while the other exchanges may be situated at variable distances from the local exchange. In a case of this kind it is desirable to charge different amounts for connections to the different exchanges in order to equitably distribute the cost of the telephone service among the difi'erent subscribers; and from what has been said already it will be understood that the charge to be assessed against the calling subscriber in any given case will be determined by the exchange in which the called subscriber is located. This in turn is determined by the level selected at the first selectors, and it follows therefore that by suitably wiring the banks of the auxiliary switches associated with the different groups of repeaters, the proper arrangement for varying the toll charges will be obtained.

[I have shown below a table which gives the toll charge per connection for each selector level, and which shows to some extent the possibilities of the system. The table is based on a charge of 5 cents for each actuation of a subscribers meter.

B-cent unit elapsed time charge time interval, in minutes.

Initial charge.

Trunk group.

In the above table the sixth level, which carries the least charge of all, is assumed to be the level which is assigned to the local trunks. One of the trunks in the first level. together with the repeater R and associated auxiliary switch P areshown in the drawing, and the manner in which the initial charge of 15 cents and the elapsed time charge of 5 cents per minute are assessed against a calling' subscriber have already been explained. According to the table the exchange which is accessible by way of the second level carries an initial charge of 10 cents and an elapsed time charge of 5 cents for every three minutes. In order to obtain this char e the auxiliary switches which are associa with the repeaters for the second level are wired as follows: Conductor 168 is connected to bank contact 166 only, while conductor 165 is connected to bank contact 164 only. A consideration of the operation of the auxiliary switch will show that with this wiring arrangement, the meter of the calling subscriber will be operated twice initially, once more after the expiration of three minutes, and every three minutes thereafter. The exchange which is accessible by way of the third level of the first selectors carries the same initial charge, but has an elapsed time charge of 5 cents for every 1% minutes. The

connections therefore are the same as just described, except that conductor 165 is connected not only to bank contact 164:, but also to bank contact 176. The next case shows the 15 cent initial charge, which is of course obtained by connecting conductor 168 to contacts 166 and 167 as shown in the drawing.

. The exchange which is accessible by way of the fifth selector level carries a 15 cent initial charge and a 10 cent charge every three minutes. In order to obtain this double elapsed time charge conductor 165 is preferably connected to bank contacts 164 and 166, while conductor 168 is connected only to bank contact 167. With this arrangement of the wiring the meter of the calling subscriber Will be operated three times initially and twice every three minutes thereafter. The wiring for the auxiliary switchesassociated with the other levels ma be calculated very easily from what has een said, and need not be explained in detail. It is to be understood that auxiliary switches having either larger or smaller contact banks may be used, and also the time mechanism T may be arranged to give a different timed impulse, that is, the interval between impulses transmitted by the time mechanism may be altered as for example, to-5 seconds or any other desired value. In this manner the system shown may be-adapted to any telephone system in order to take care of the different toll charges which are considered to be most desirable under the circumstances, although the arra ement shown will probably be found siifliclently flexible under ordinary conditions. i

It will be seen from the foregoing that I have devised a measured service system in which a variable initial charge is assessed against a calling subscriber, depending on the exchange to which he has extended a connection; and in which an elapsed time charge is assessed against a calling subscriber which also is variable, either as to amount of the unit charge or as to the rate at which the unit charge is assessed, all

depending as in the case of the initial charge on the exchange to which the connection has been extended.

Having described my invention, what I consider to be new and desire to have protected by Letters Patent will be pointed out in the appended claims.

What I claim is:

1. In a telephone system, a pluralit of exchan 'es, means for connecting a ca ling subscri er in one of said exchanges with called subscribers in the other exchanges, 'toll assessing mechanism operated automatically in the course of such connections to assess periodic elapsed time charges against the calling subscriber, and means for varying the amount of the said periodic charges assessed durin the different connections and also the time intervals intervening between the assessing of successive charges, both the amount of the charge and the time interval being varied in accordance with the exchange in w ich the called subscriber is located.

2. In a telephone system, a pluralit of exchanges, means for connecting a ca ling subscriber in one of said exchanges with called subscribers in the other exchanges, toll assessing mechanism operated automatically in the course of such connections to assess against the calling subscriber an initial charge at the beginning of each conversation and periodic elapsed time charges during each conversation, and means for varying the amount of the initial charges and also the time intervals intervening between the assessing of successive elapsed time charges, both variables being adjusted in accordance with the exchanges in which the called subscribers are located.

3. In a telephone system, a plurality of exchanges, means for connecting a calling subscriber in one of said exchanges with called subscribers in the other exchanges,

toll assessing mechanism operated automati-' cally in the course of such connections to assess against the calling subscriber an initial charge at the beginning of each conversation andperiodie elapsed time charges during each conversation, and means for varying the amount of the initial charge, the amount of the periodic elapsed time charge, and the length of the elapsed time charge time interval, all of said variables being adjusted in accordance with the exchanges in which the called subscribers are located. I

4. In a telephone system, calling and called lines, means for extending connec-. tions from the calling line to said called lines, a meter for the calling line, a meter controlling device operated when connection is extended to one of said called lines for operating the meter a predetermined num- 'ior causing said device to operate said meter a certain reduced number of times for each interval or time the connection is held.

5. In a telephone" system, subscribers lines, a meter for each line, trunk lines for extending connections between said lines, and an auxiliary meter controlling switch for one of said trunk lines, said switch having a series of contacts so connected as to operate the meter of a calling line a plurality of times when the wiper of the switch traverses said contacts the first time, and a lesser number of times each time said wiper traverses said contacts thereafter in the same connection. I

6. In a telephone system, subscribers lines, a meter for each line, trunk lines, means for establishing connections between any of said lines over said trunk lines, and an auxiliary switch associated with one of said trunk lines for controlling the operation of a calling subscribers meter, saidv switch operated during conversation over its associated trunk line to first operate the meter a plurality of times to assess a line charge, and thereafter to operate the meter a reduced number of times for each interval of elapsed time.

7. In a telephone system, calling and called lines, a meter for the calling line, trunk lines, means for establishing connection between said lines over said trunk lines, a rotary switch associated with a trunk line for controlling the meter of the calling line when the trunk line is used, certain of the contacts of said switch being connected to ground and said switch having a wiper for engaging said grounded contacts to send a plurality of impulses to the meter during the first rotation of the switch, and means for disconnecting the ground from certain of said contacts after the first rotation to cause the meter to be operated a reduced number of times for succeeding rotations of said switch.

8. In a telephone system, a plurality of exchanges, means for extending connections from a calling subscriber in one exchange to called subscribers in the other exchanges, a toll assessing device operated when a connection is extended to a called subscriber in a certain exchange for assessing aninitial trunk charge against the calling subscriber and also an elapsed time charge at predetermined intervals during the conversation, a different toll assessing device which is operated when the called subscriber is located in each of the other exchanges, and different circuit connections in each toll assessing device, whereby the initial charge, the elapsed time charge, or the predetermined time. in-

,terval may be varied in accordance with the exchange in which the called subscriber is located.

.9. A meter controlling device comprising a bank of contacts, a wiper, a motor magnet for driving said wiper over said contacts repeatedly, a main meter control wire connected to one of said contacts, a branch wire connected to another of said contacts, and

means for automatically disconnecting said branch wire from the main wire before said wiper is driven over the said contacts the second time. v c

10. A meter controlling device comprising a continuously driven switch, a meter control wire, means operated at a certain stage in the operation of said switch for transmitting a series of impulses over said wire, said means being eifective the first time the switch passes through such stage, and a switching device for causing said means to transmit a different series of impulses over said wire the next time the switch passes through such stage.

11. In a meter controlling device, a continuously revolving operating member having active and passive positions through which it passes alternately, a meter control circuit closed a plurality of times by said member the first time it passes through its active position, and a switching device for causing said member to close said circuit a different number of times the next time it passes through its active position.

12. In a telephone system, a meter, common mechanism for causing said meter to record a call charge and additional duration charge, the respective charges being constituted of one or more impulses to the meter, the impulses emanating from a source apart from the common operating mechanism. and

vmeans for preventing the application of impulses constituting the time charge being applied untilafter the impulses constituting the initial charge have been applied.

13. In a. telephone system, a toll meter including common operating mechanism for recording a call charge and an additional duration charge a meter control conductor over which only impulses effective to control the meter in accordance with the initial charge are transmitted and another meter control. conductor over which impulses are transmitted which control the meter in accordance with both the initial and duration charge.

14. In a telephone system, a toll meter including common operating mechanism for recording a call charge and an additional duration charge, the respective charges being constituted of one or more impulses operative to the meter, the said charge impulses emanating from different sources apart from said operating mechanism, an oscillatory wiper and means whereby the said impulses constituting the call charge are picked up by said wiper during one oscillution and whereby the impulses constituting a duration charge are picked up by a subsequent oscillation of said wiper.

15. In a telephone system, a toll meter including common operating mechanism for recording a call charge and an 'yadd1t1onal duration charge, the respective charges being constituted of one or more impulses operative to the meter, the said charge impulses emanating from different sources apart from the said operating mechanism,

and means including a wiper and an associ- Signed by me at Chicago, Illinois, this- 22d day of January, 1920.

-- BERNARD D. WILLIS.

Images