US1350875A - Measured-service telephone system - Google Patents

Description

T. G. MARTIN. I MEASURED SERVICE TELEPHONE SYSTEM.

APPLICATION FILED 050.24. 1911.

1 ,350 87 5 V Patented Aug. 24, 1920.

fnuanlm" Til/J52 E a'rZLn HZZUrnEy UNITED STATES PATENT OFFICE.

TALBOT G. MARTIN, OF CHICAGO, ILLINOIS, ASSIGNOR TO AUTOMATIC ELECTRIC COMPANY, OF CHICAGO, ILLINOIS,

A CORPORATION OF ILLINOIS.

MEASURED-SERVICE TELEPHONE SYSTEM.

Application filed December 24, 1917.

To all u /mm it may concern:

Be it known that I, TALBOT MARTIN, 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 automatic telephone systems. It relates more specifically to improvements in automatic switches for such systems and to improved means for registering calls in an automatic system.

In a telephone system'it is of considerable value to the operating company to be able to inform a subscriber as to the number of times his line has been called while busy. For instance where an ofiice has only one telephone and a number of calls come in which are lost by reason of the said tele phone being in use, the company can more easily persuade the subscriber that another instrument should be installed it they can give him accurate information as to just how many calls were turned away when his telephone was busy. In order to obtain this information a meter must be provided to register such busy calls.

My invention provides such a nieter and is shown in connection with automatic switches of a well known type, it being understood, however, that I do not wish to limit myself to the exact type of switches shown, but that such an arrangement may be provided in connection with any well known type of switches without departing from the spirit of my invention.

To accomplish the foregoing and other useful ends my invention relates to matters hereinafter more specifically set forth and claimed.

In the accompanying drawing I have illustrated an established connection between calling subscriber A and called subscriber B. Associated with, and individual to the calling subscribers line is shown a line switch C of the plunger type shown in British Patent to Martin #1419 of 1910. which has access to a number of trunk lines leading to connector switches, similar to that shown at D, which are in turn operated to connect with and signal any called subscriber.

Although I have shown my 1nvent1on 1n Specification of Letters Patent.

Serial No. 208,579.

connection with a one hundred line system it will be understood that the capacity of the exchange may be increased by inserting one or more selectors of the well known Strowger type between the line switch C and the connector D.

I will now e:;lain more in detail how a connection may be extended from a calling to a called subscribers line and how when connection is made with a called line which is busy, a special meter provided for that purpose will operate to register the call.

hen the subscriber A removes his receiver to initiate a call he closes an energizing circuit for the line relay 2 of line switch C as follows; from ground G through springs 3 and 4, line conductor 5, transmitter 6, receiver 7, calling device springs 8, hook switch springs 9 and 10, line conductor 11, springs 12 and 13, and through relay 2 to battery B. Line relay 2 energizes and closes a circuit for the pull down coil 16 from ground G through the springs M and 15, and said winding 16, to battery. l he pull down winding 16 thereupon energizes to disconnect the line relay 2 and ground G from the line conductors 5 and ll'by means of the armature 65 and also operates the plunger (not shown) to force into contact in pairs the springs 17 and 18, 19 and 20, 21 and 22, and 23 and 24. The closure of springs 17 and 18 and 23 and 24: extends the line conductors 5 and 11 to the conductors leading to connector D. It is to be understood that the usual master switch is user. in a system of this character and operates to always maintain an idle connector switchD accessible to the line switch C, and also that although only one set of springs 17- 2%- is shown, each line switch is provided with a set forming the terminal of a trunk line leading to a connector switch D. The extension of the line conductors 5 and 11 as explained the trunk line leading to con nector D causes an energizing circuit to be closed for the D which extends over the conductors 5 and 11 and through the substation A. The relay 26 ,upon energizing closes a circuit for the slow acting relay 2? from ground G through springs 28 and 29 and through relay 2'? to battery B Relay 27 thereupon energizes anal closes a holding circuit for the holding Patented Aug. 24, 1920.

plurality of such sets, each winding of line switch C through springs from ground G The relay 2 of the line switch U being slow-acting, does not allow its armature 14 to fall back as soon as its circuit is opened by the pull down coil 16,

but maintains the circuit of the winding 16 closed at springs 14 and 15 until the above 7 The calling subscriber now operates his dial in accordance with the first digit of the called subscribers number thereby opening the circuit of the line relay 26 a corresponding number of times by separating the springs 8 of his dial. The relay 26 thereupon deenergizes a number of t1mes and each time the armature cuit' is closed for the vertical magnet 32 and relay 34 in series to step the wipers 35-7-38, inclusive, up to a certain level of the connector bank in which are located the terminals leading to the desired subscribers line. The circuit-for the vertical magnet may be traced irom ground G springs 28 and 39, springs 33, relay 34, vertical magnet 40 in first position to 32, and side switch battery. As soon as the wipers are raised one step by the operation, of the vertical magnet the ofi normal springs are operated to close the circuit of the release magnet 31 at springs 43 and to close a circuit for the meter relay 52 at the springs 42. The energization of the relay 52 at this time is without effect as the circuit for the meter F is held open at the springs 77 of the busy relay 51. However, relay 52 closes apair of springs 78, which are in series with the meter F of the called substation but which circuit is now open at the wiper 37 and which is also open at another point at the springs 77 of relay 51. Relay 34 being a slow acting relay will maintain its armature 44 in attracted position as, long as relay 26 is operating in response to impulses, thereby closing a circuit for the private magnet 48 from ground through springs 44 and 45, and the said private magnet 48 to battery. As soon as the impulses for the first digit cease however, the relay'26 willremain in its attractor position and relay 34 will fall back, thereby opening the circuit for the private magnet 48 and through the deenergization of said private magnet, causing the side switch wipers 40 and 41 to pass to second position in a well known manner, substituting the rotary magnet 47 to the control of the line relay 26 in place of the vertical magnet 32..

Relay 27 also opens a contact 28 falls back a cir-.

63, side switch wiper 40, to battery.

The calling subscriber may now operate his dial for the second digit of the called number by separating the springs 8 of his calling device a number of times, the line relay 26 in response tothe impulses for this digit again falls back a corresponding number of times and upon each deenergization, closes a circuit for the rotary magnet 47 and the slow relay 34 in series. This circuit may be tracedji'rom ground G through springs 28 and, 39, relay 34, springs 46, rotary magnet 47,- and side switch wiper 40 (in second position) to battery. The rotary magnet 47 operates in'response to the im pulses over the above circuit to rotate the wipers 35-38 inclusive, around to the contacts of the bank corresponding to the desired line and the relay 34 also operates to again close the circuit of the private magnet. Assuming that the called line is idle and there is no ground on the contact upon to the private wiper 38, to guard the called,

line against seizure and also to close an energizing circuit for the bridge cut-ofi" winding 25 of the line switch 0' to disconnect the line relay 2 and ground from the called line in the usual manner.

The side switch wiper 40 upon passing to third position supplies battery to the other end of relay 63, which relay energizes at this time to connect the ringing generator with the called line.

The circuit of the relay 63 may be traced from ground G side switch wiper 41, relay Relay 63 upon energizing closes the springs 68 and 69 to signal the called subscriber and also opens a pair of springs in the circuit of the meter relay 52 which relay thereupon deenergizes.

As soon as the line circuit is cut through by relay 63 the called subscribers bell is operated over a circuit extending from battery B through the upper winding of relay 54, springs 66 and 67, springs 68, wiper to and through the bell of substation 1%, wiper 36, springs 69, springs 70 and T1,

' through the contacts of an interrupter relay transmitter and receiver for the bell and condenser at the telephone of substation B.

elay 54 then energizes over the above traced circuit and locks itself to ground -at off normal springs 42 and through its own springs 74 and its lower winding to battery B Relay 54 upon energizing also disconnects the leads from the interrupter relay armature and its own upper winding from the called line to out be the ringing current and also cuts the line conductors from the calling station through to the called line.

The called subscriber now receives talking batterythrough the two windings of the back bridge relay 53 and conversation may be carried on over the talking circuit which is shown by heavy conductors. v i

The release of the connection is controlled by the opening of the line circuit at the springs 9 and 10 of the calling station when the called subscriber restores his receiver. This opening of the line circuit causes the line relay 26 of the connector D to fall back to in turn open the circuit of slow aetin release relay Relay 2? then falls back, closing a circuit for the release magnet 31 at the back contact of its upper springs and opening the holding circuit for the switching relav 25 of theline switch C. The entire apparatus is thereby restored to nor- "mal inthe usual manner and the circuit of the release magnet 31 is opened at springs 43 when the shaft reaches normal position.'

I will now explain hoW the meter F is operated: Assuming that the called line is busy when an attempt is made to establish connection therewith either by reason of its being called orfmaking a call, there will be aground potentialon the private normal contact with which the wiper 38 makes connection. Now as soon asthe impulses for the second or last digit of. the called number cease and before the private magnet has been deenergized by the falling back of slow relay 84, a circuit will remain closed for a moment from the private wiper 38 through the 'sideswitch wiper 41 (in second position) and relay 51 to the spring 49 of relay 34. Now when the relay 34 falls back after the cessation of impulses, the private magnet will not 'deenergiz'e but will be held energized over the above traced circuit from ground on the private wiper, through side switch wiper 41 (in second position) springs 50 and 55, relay 51, springs 49 and 45, and

private magnet 48 to battery, .As the spring 45 makes contact withthe spring 49 before disengaging from the spring 44 it will be seen that the private magnet circuit is not opened and that the side switch wipers 40 and 41 will be held in second position. Relay 51 also energizes in series with magnet 48 and closes a locking circuit 'foritself through springs 55 and 56 and the off normal springs 42 to ground, and also closes thesprings 76 to supply busy signaling current from the busy machine H to the calling line to inform the calling subscriber that the called for line is busy. The energization of relay 51 also closes another point in the circuit of the meter F at the springs 77 and also opens the circuit of the meter relay 52at the springs 79 and opens the circuit of the rotary magnet at the springs 46. The relay52 is slow acting and although its energizing circuit is broken at the springs 79, it maintainsits armature in attracted position, long enough to send a momentary impulse of current to the meter F over the following circuit: From ground through springs '42, springs 77, springs 78, wiper 37, and through the meter F to battery. A moment'after its circuit is opened at the springs 79, the relay 52 deenergizes to open the circuit of the meter F at the springs 7 8. It will be seen therefore, that the meter F 01)- erates only once for each call to a busy line and that the switch then remains locked on the busy line until released in the usual manner by the hanging up of the receiver at the calling station. Also it will be seen that, as the meter F only receives a momentary impulse of current each time a connector lands on the busy line to which it is attached, any number of connectors may call this busy line at frequent intervals and even though one of said switches remains locked'on said line for a length of time, still the meter will be free after each momentary impulse to receive another charge from another connector.

It will be seen therefore, that I have devised a very simple and efiicient method of metering calls to a busy line, at the same time making it impossible for said meter to be operated more than once for the establishment. of a single connection.

What I claim as my invention is: 1. In a telephone system, subscribers lines, means for extending a connection from a calling to a called one of said lines,

said called line is busy.

2. In a telephone system, a subscribers line, means for making said line busy to calls from other subscribers, a meter for said line, and means for operating said meter when another subscriber attempts to establish a connection with said busy line.

3. In a, telephone system, a subscribers line, means for making said line busy to calls from other subscribers, a meter for said line, and means for op'eratingsaid meter each time another subscriber attempts to establish a connection with said busy line.

4. In a telephone system, a subscribers 5.. In a: telephone system, a subscribers line, means for making. said line busy, a

connector switch, means for. operating said connector switch to test said subscribers line; a .meter for said line, and means con 7 trolled bysaid. connector switch for operating said meter when the line is tested and found busy.

6. In a telephone system, a subscribers line, means for making said line busy, a

connector switch, means for operating said connector switch to test said subscribers line, means and found busy.

line,-a meter forsaid line, and a quick and slow relay in said connector switch for operating said meter when the line s tested 7. In a telephone said line, a connector switch, means for operating said connector switch to test said subscribers line, a meter for said line, and

' means controlled by said connector switch I 7 tested and "foundbusy.

,line',-means for making said line busy when l line a v r V a v meter for said line tor registering the number of calls made to said line when busy, a

circuit for said meter, and quick and slow line, a 1116i6I" for said line,

switchesfmeans for operating one of said a quick and slow for operating said meter when the line is c 8. In a telephone system, a subscr'ibers a connection is entended either to or from said line, a connector switch, means for operating saidconnector switch to test said. tor said line, and relay in said connector switch for operating said meter when the;

subscribers line a meter line ist'ested and found busy. v

9. In a telephone system, subscribers means for making said line busy, a

relays for controlling said'circuit to operate said meter.

10. In a telephone system, a subscribers connector connector switches to establish a connection with said line and establish a guarding potential thereat, means for then operating another of said switches to test said called line, and meaiis'in said connector switchresponsive to said guarding potential for opf 'line, means for makingsaid li b t calls from other subscribers, a meter for said erating'said meter.

11. In a telephone system, a subscribers line, a meter for said line, connector switches, connector switches to establish a talking circuit with said line and establish a guarding potential thereat, means for then operv ating another of said switches to test said called line, and means in said connector system, a subscribers; for making said line busy when a connection is extended either to or from 1 'means for operating one of said switchresponsive to said guarding potent al tor operating said meter'over a circuit independent of said talking circuit.

12. In a telephone system, a. subscribers line, a meter for said line, connector switches,.means for operating one of said connectorswitches to. establish a connection with said line and establish a guarding po- .tential thereat, means for then operating a nothei' of said switches to test said called line, and qu ck and slow relays in said connector switch responsive to said guarding "potential for operating said meter.

line, and quick and slow relays in said connector'switch responsive to said guarding potential for operating said meter over a circuit independent ofsaid talking circuit.

14. In a telephone system, a subscribers a meter for said 'line, connector switches, means for operating each of said connectors to test and connect with said line, means for preventing the connection of more than one of ,said connector switches with said line, and means in each switch for operating said meter momentarily when it connects withsa' d line while another of said switches-is connected thereto.

-15. In a telephone system, a subscribers line, means for making said line busy to *zlls from other subscribers, a meter for said line, and means for operating said meter momentarily when another subscriber attempts to establish a connection with said busy line. V i

16. Ina telephone system, a subscribers .line', n eans formaking said line busy to calls "from other subscribers, a meter for said 'j-line, vand means for operating said meter niomentarily each time another subscriber attempts establish a "connection with said busy line. I

17. In ajtelephone system, a subscribers line, means formaking said line busy, a meter for said line for registering the number oi calls made to said line when busy, a circuit for said meter, and quick and slow relays for momentarily controlling said circuit to operate said meter.

18. In a telephone system, a 'subscribers line, and electromagnetic means for operating said meter when another subscriber attempts to establish a connection with said busy line. i i

' 19. In a telephone system, a subscribers line, means "for 'making said line busy to calls from ethersubscribers, a meter for said line, and a circuit for operating said meter each time another subscriber attempts to establish a connection with said busy line.

20. In a telephone system, a subscribers line, means for making said line busy to calls from other subscribers when a call is extended either to or from said line, a meter for said line, and a circuit for operating said meter when another subscriber attempts to establish a connection with said busy line.

21. In a telephone system, a subscribers line, means for making said line busy, a connector switch, means for operating said connector switch to test said subscribers line, a meter for said line, and a circuit controlled by said connector switch for operating said meter when the line is tested and found busy.

22. In a telephone system, 'a subscribers line, means for making said line busy when a connection is extended either to or from said line, a connector switch, means for operating said connector switch to test said sulr-scribers line, a meter for said line, and a circuit controlled by said connector switch for operating said meter when the line is tested and found busy.

23. In a telephone system, a subscribers line, a meter for said line, connector switches, means for operating one of said connector switches to establish a connection with said line and establish a guarding potential thereat, means for then operating another of said switches to test said called line, and

a relay in said connector switch responsive to said guarding potential for operating said meter.

24. In a telephone system, a subscribers line, a meter for said line, connector switches, means for operating one of said connector switches to establish a talking circuit with said line and establish a guard ing potential thereat, means for then operating another of said switches to test said called line, and a relay in said connector switch responsive to said guarding potential for operating said meter over a circuit independent of said talking circuit.

25. In a telephone system, a subscribers line, a meter for said line, connector switches, means for operating each of said connectors to test and connect with said line, means for preventing the connection of more than one of said connector switches with said line, and a relay in each switch for operating said meter momentarily when it connects with said line while another of said switches is connected thereto.

26. In a telephone system, a subscribers line, means for making said line busy, a meter for said line, means for operating said meter when said line is called while busy.

Signed by me at Chicago, Cook county, Illinois, this 17th day of December, 1917.

TALBOT G. MARTIN.

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