US2057083A

US2057083A - Signaling system

Info

Publication number: US2057083A
Authority: US
Publication date: 1936-10-13
Anticipated expiration: 1953-10-13

Description

J. O. CARR SIGNALING SYSTEM Oct. 13, 1936.

Filed Feb. 21, 1928 I I I I I l I I l J (019 III P Patented Oct. 13, 1936 PATENT OFFICE SIGNALING SYSTEM John O. Carr, Chicago, Ill., assignor to Teletype Corporation, Chicago, Ill., a corporation of Delaware Application February 21, 1928, Serial No. 255,918

9 Claims.

My invention relates to signaling systems and more particularly my invention relates to intercommunicating systems especially adapted for operation between outlying stations in which the telegraph or other signaling apparatus located thereat is normally maintained in a non-operating condition and is arranged to be started into operation from a central station.

With the expansion of telegraph systems, automatic apparatus is being made part of the equipment in outlying stations where the normal amount of trafiic is not sufficient to keep the system in continuous operation. A need has therefore risen for the development of circuit arrangements whereby the apparatus in these outlying stations can be normally maintained in a nonoperating condition and automatically started into operation from a central station to permit intercommunication between these outlying stag" tions.

An object of my invention is to provide means for normally maintaining the automatic signaling apparatus at all of various outlying stations normally in non-operating condition and remotely disposed switching mechanism arranged to selectively start the apparatus into operation for intercommunication between the outlying stations.

Another object of my inveition is to provide 39 simple circuit arrangements whereby an operator at a central station can with the use of the regular telegraph line start into operation and interconnect the telegraph apparatus at two outlying stations. Still another object of my invention is to provide means for varying the constants of a telegraph circuit to permit communication between any of a number of remotely disposed stations at unequal distances apart.

Other objects of the invention together with the foregoing will appear in the specification which follows and are such as may be attained by a utilization of the various combinations, subcombinations and principles hereinafter set forth Referring to the drawing:

The figure shows in diagram the apparatus and circuit arrangements employed in carrying out the form of my invention.

Referring nowmore particularlyto the drawing, a plurality of outlying stations A to F are shown with circuit connections to a central station G. Located at each of the outlying stations is a telegraph typewriter unit comprising preferably a 55 transmitting contact I, of a single contact transand defined by the terms of the appended claims.

mitter and a selector magnet 2 connected in series with the transmitter contact and controlling a printer such for example as is disclosed in the patent to Kleinschmidt 1,567,392 issued December 29, 1925. Although a single magnet printer and single contact transmitter is illustrated for purposes of convenience, it will be evident from the description which follows that any other form of telegraph apparatus may be employed. The transmitting contact I is normally closed and is preferably shunted by a condenser 3. The transmitter and receiver are driven by a normally nonoperating motor 4 supplied by energy from the source of the circuit for electrical energy 5 and the circuit of which is controlled by the armature of biased polar relay 6. Relay 6 is biased to hold the circuit for motor 4 closed. With a current of positive polarity impressed on the polar relay 6, the bias is overcome and its armature is held in position to break the motor circuit. When current of opposite polarity or negative current is impressed on polar relay 6, the armature of relay 6 is moved to its biased position, closing the motor circuit. Thereafter the armature remains in this position until the polarity of the current through winding of relay 6 is again reversed to move the armature from its biased position to open'the motor circuit. The polarity of the current normally impressed on the relay 6 is such that it holds the circuit of the printer motor 4 open as shown. The printer is thus normally maintained in a non-operating condition.

The main winding of polar relay 6, the transmitter contact i and the printer operating relay 2, are connected in series with the signaling line 1 through hand signaling key 1'. Line 1 connects the outlying station A with the central operating station G.

Located at the central operating station there is a switching unit and signal device individual to each outlying station comprising an answering jack 8, called jack 9, calling jack l0, and neutral relay I i connected in the signaling line 1. Relay ll controls an energizing circuit for signal lamp ll The calling jack 10 comprises a spring I2 operating between two contacts l3 and I4, and spring l5 normally in engagement with its lower contact is. The contact I6 is connected through resistance IT to ground at I8 and controls the ground return circuit which may be completed through resistance I! or directly to ground in a manner to be described hereinafter. The spring I5 is connected to the signaling line 7 extending to the outlying station and is also connected over side of battery 34 thru this contact.

Called jack 9 comprises a spring 20 normally disengaged from contact 26 and spring 21 normally in engagement with contact 28. Contact 26 is connected to ground at I8 over conductor 29 and prepares an electrical path which shunts resistance |1. Spring 21 is connected to the signaling line 1.

The answering jack 8 comprises springs 23, 25 and 3|.

The other side of the battery-is grounded at 35. Negative potential from battery 34 is impressed on the signaling line overconductor 24 and spring |2 of the calling jack ID as will be described in more detail hereinafters 1 Spring 23in engagement with contact 36 is connectedto the spring 21 over the conductor 31 for controlling the circuit from the positive side of battery 2| to signaling line 1.

An answering set comprises printer operating relay 40 for operating a single magnet printer and transmitter contact 4| of a single contact,

transmitter is located at the central station for signaling with any one or more of the outlying stations and is connected in series with plug 42 over the conductor 43. The plug 42 when inserted in answering jack 8, will move spring 25 to disengage its contact 33, spring 23, to disengage contact 36 and spring 3| to engage contact 44. Connecting cords such as for completing circuits from the calling jack individual to one station with the called jack of another station is also part of the central station equipment.

Although a plurality of batteries have been shown for purposes of convenience in illustrating the invention, it will be understood that in practice, a single battery may be employed.

Having described theapparatus and the circuit arrangements in general, a detailed description of the operations, which take place in connecting any two outlying stations for inter-communication will now be given.

With the apparatus in its'normal non-operating condition, there are no plugs inserted in the jacks and connections are made as shown in the drawing. Current of positive polarity is impressed upon the signaling line 1, extending to outlying station A from ground through the battery 2| at the central station, the contact I3 in engagement with spring I2, conductor 22, spring 23, in engagement with its contact 36, conductor 31, the contact 28 in engagement with spring 21., relay over the signaling line 1 to the outlying station A through the winding of the operating magnet 2, transmitter contact polar relay 6, and over the signaling line 1 and to spring IS in engagement with its contact l6 and resistance l1 to ground. A similar circuit impressing positive current on the signaling line is completed through all the other jacks and their associated outlying stations.

With the system in this condition, the bias winding of the polar relay 6 maintains its armature in the position shown and the circuit for the Spring 25 is normally in engagement with contact 33 and is connected to the negative motor operating the telegraph apparatus is open at this armature. The telegraph apparatus is therefore normally in non-operating condition. Assuming the operator at the outlying station A, desires to communicate with outlying station B, he will call the central station by momentarily opening signal key 1. Relay II will be de-energized during the momentary opening of the line to close 'a circuit for the lamp II. This will be repeated until the operators attention is attracted. The operator at the central station when thus attracted will insert plug 42 in the answering jack 8, disengaging the springs 25 and 23 from their contacts and closing the contact 44 and spring 3|. The disengagement of'the con: tact 36 from spring 23 disconnects the positive battery from the signaling line 1 the circuit for which as will be recalled from the description above, was completed through this contact.

The circuit for battery 34, which is completed through spring 25 and the conductor 24 to the calling jack at contact M is opened at contact 33.

spring 3| and plug 42 over conductor 43 to the tact transmitter 4| in series to the connector 46,

conductor 31, contact 28, spring 21, relay signaling line 1, to the winding of the printer operating relay 2 transmitter contact I, polar relay However, a circuit is completed from ground through battery 34, contact 44 in engagement with- 6, to the spring l5, contact I6 and through resistthrough the contact 44 at the answering jack, the

telegraph apparatus at the central station, over the spring 21 of the called jack 9, and thence to the signaling line 1.

When the negative potential is thus connected 7 to the signaling line 1, polar relay 6 operates its armature, closingthe energizing circuit for the motor 4. Motor 4 starts the printing set at the outlying station A into operation.

With the motor at the Outlying. station. now in operation, telegraph signaling can now take place between the outlying station A and the central station G, the signalingycircuit traced above, being completed thru the contact of'the transmitter and the receiving relay '2 at the outlying station and thru the transmitter contact 4| and the receiving relay 40 at the central station. Synchronism between these telegraph sets will be maintained inthe manner well' known in the art and is not shown as itdoes not form part of this invention.

If now the operator at the outlying station A desires to get into communication with the opcrater at the outlying station E, he transmits this information to the operator at the central station G. Upon receipt of this information, the operator at the central station will insert plug 41 into the calling jack I0 associated with the calling outlying station A, and insert plug 48 into the called jack 9 of the outlying station B.

Inserting the plug 41 into the calling jack I0 disengages the spring l5 from its contact l6,

removing the ground connection at this point and simultaneously extending this circuit thru the connection cord 45. At the same time spring I 2 ismoved to disengage contact l3 and engage contact I 4, opening a further point in the circuit of battery 2| and preparing a circuit for the battery 34 from spring 25 of answering jack 8. This circuit is however, at this time still open at spring 25.

Plug 48 at the opposite end of the connecting cord when inserted in the called jack 9 associated with outlying station B, disconnects spring 27 from its contact 28 and connects spring 2!! with contact 26. Disengagement of spring 2! from contact 28 opens the circuit of battery 2| completed over signaling line 1 to outlying station B, thereby removing the positive potential from this line. The engagement of spring 29 and contact 26 connects the signaling line 1 directly to ground at l8 by passing resistance H, the circuit to ground having formerly been completed over spring l5, contact l6 and resistance IT as was described in detail above.

A circuit is now completed from ground at the central station through the negative battery 34, the contact 44 of answering jack 8 associated with outlying station A, plug 42, conductor 43, receiving relay 46, transmitter contact 4i, connector 46, conductor 31, contact 28, spring 2V, relay ll, signaling line i to the outlying station A, printer operating relay 2, transmitter contact I, the winding of polar relay 6, the other side of the signaling line 1, spring i5 in engagement I with the plug 41, connecting cord 45, plug 48 in engagement with the spring 27, of the called jack 9 associated with the outlying station B relay ll one side of the signaling line i extending to the outlying station E to the winding of the printer operating relay 2, transmitter contact I, the winding of the biased polar relay 8, the other side of the signaling line 1, spring as in engagement with its contact 26 to ground over conductor 29.

As a result of negative polarity being impressed upon line I to station B, the armature of polar relay 6 at that station moves to engage its front contact to complete the circuit for the motor 4. As the motor circuit is thus completed, it starts into operation and in turn starts the telegraph apparatus at the outlying station B into operation.

The signaling circuit is now completed over the circuit which was traced above for permitting signaling between the outlying station A and outlying station B, the circuit being completed through the printer relays and transmitter contacts at each station in series. It will be noted also that in the above circuit the receiving relay and transmitter contact of the telegraph set at the central station is also connected in the circuit.

If desired, however, the operator at the central station may disconnect the answering set by removing the plug 42 from the answering jack 8. The battery 34 will then still be connected to the circuit traced above except that instead of being directly connected to the signaling line ll over conductor 31, the circuit is now completed from ground through the battery 34 over the contact 33 in engagement with spring 25 of the answering jack 8, conductor 24, the contact 14 in engagement with spring I2, conductor 22, spring 23 in engagement with contact 36, conductor 31, contact 28 in engagement with spring '31, relay H over signaling line i to the telegraph apparatus at outlying station A. The circuit from this point on including the apparatus at receiving station B is identical with that traced above.

The circuit, it will be noted, is now again completed from the receiving and transmitting apparatus at each of the outlying stations through the calling jack individual to station A, and called jack individual to station B. Signaling between outlying stations A and B can now be conducted in the usual manner.

As soon as the operators at the two outlying stations are through communicating with each other, the operator at the central station removes the plug 41 from the calling jack l0 and called jack 9. As a result the battery 34 is disconnected from the circuit traced above and the circuits originally traced including battery 2| are completed through the individual jacks to each outlying station. A potential of positive polarity is impressed on the signaling line I by battery 25 and as a result the polar relays function to move their armatures to disengage to open the circuits of the motors 4. The telegraph apparatus is thus restored to its normal non-operating condition.

It will be noted that during the signaling operations above described, the relay H is energized and deenergized as the signaling line is opened and closed to transmit signals. As the relay ill is energized and deenergized, the lamp i flashes. The operator is thus provided with an indication that the connected stations are communicating. At the end of the signaling, the dashing will stop and the operator will therefore break circuit inter-connection. Outlying stations C to D are each separately connected to the central station G as are stations A and B.

It will be evident from the above description that a very simple arrangement is provided for maintaining the apparatus at various outlying stations normally in non-operating condition while at the same time by comparatively simple circuit arrangements including only the regular signaling line, the telegraph apparatus can be started into operation from a central or connecting station to enable intercommunication between outlying stations or between one or more outlying stations and the central station. It is evident of course, from the above description that any number of outlying stations can be connected in circuit with each other.

Although I have shown my invention as applying to a manual exchange station, it is evident of course, that my invention has application also to an automatic or semi-automatic central station.

Having described preferred embodiments of my invention, what is desired to be secured by Letters Patent and claimed as new is:-

1. In a signaling system, a central station, a plurality of outlying stations, a plurality of lines connecting said outlying stations individually to said central station, automatic telegraph apparatus at each of said outlying stations and at said central station, means for electrically connecting said central station telegraph apparatus to any one of said outlying stations, and means for electrically connecting said outlying stations to each other in a plurality of concurrent connections for independent intercommunications, said means being simultaneously operative for changing the signal line characteristics to compensate for the line resistance between said central oflice and said outlying stations.

2. In a signaling system, a plurality of outlying stations, a central station, a plurality of electrically independent signaling lines connecting said central station with each of said outlying stations individually, telegraph apparatus at each of said outlying stations and at said central station, means including pairs of said signaling lines between said central station and pairs of said outlying stations for signaling between pairs of said outlying stations in a plurality of concurrent connections for independent intercommunications, and means for modifying the characteristics of said circuits to compensate for the resistance in any of said connections between said outlying stations.

3. In a telegraph system, a plurality of stations and a central station, a plurality of station telegraph sets and a central station telegraph set, a central switchboard comprising jacks and resistances individual to each of said stations, switching contacts in said jacks, circuit connections including said contacts of said jacks and said resistances between each of said stations and said central switchboard, means including the contacts of one of said jacks and one of said resistances to form a communication connection including one of said stations and one of said resistances and said central station telegraph set, and further means for forming a plurality of concurrent intercommunication connections including said stations in pairs and excluding said resistances.

4. In a telegraph system, a plurality of outlying stations, a central station, circuit connections between said central station and each of said outlying stations, circuit resistances at said central station and one included in each of said circuit connections, signaling means including one of said circuit connections for signaling between one of said outlying stations and said central station and including in each such signaling means the individual circuit resistance of the outlying signaling station, and means at said central station for connecting a plurality of said outlying stations to each other in pairs for concurrent independent intercommunications and for simultaneously excluding said circuit resistances to compensate for the increased line resistance in each connection between outlying stations.

5. A printing telegraph exchange system comprising a central station, a plurality of subscriber stations, a plurality of telegraph subscriber lines interconnecting said central station and said subscriber stations, a plurality of resistances in series with said lines individually, central switching means to effect a communication circuit comprising said central station, a subscriber station, a line and its individual resistance in series, manually operable link circuits at said central station for interconnecting said subscriber stations, means at each of said stations for transmitting and receiving impulses, and means at said central station effective upon interconnection of any two of said subscriber lines for compensating for the increase in resistance in the signaling circuit including said transmitting and said receiving apparatus by excluding said resistances from the signaling circuit. 7

s 6. A printing telegraph exchange system. comprising a central station, a plurality of subscriber stations, a plurality of telegraph subscriber lines interconnecting said central station and said subscriber stations, link lines at said central station, means at each of said stations for transmitting and receiving impulses over said subscriber lines, said subscriber lines being of a predetermined resistance, means at said central station to connect one of said subscriber lines to said central station for communication While maintaining the full predetermined resistance value of said connected line, and means effective upon interconnection of any two of said subscriber lines by the link lines for automatically reducing the resistance of each of said subscriber lines to compensate against increased resistance of said lines in series.

7. In a printing telegraph exchange, a plurality of signaling circuits each comprising a resistance,

a line conductor and a telegraph station set, a further telegraph station set, switching means to connect said further set in series with one of said circuits While retaining said resistance in said circuit, and further means toconnect together two of said signaling circuits in series and excluding said resistances of said connected circuits.

8. In a printing telegraph exchange, a plurality of signaling circuits each comp-rising a resistance, a line conductor and a telegraph station set, a further telegraph station set, switching means to connect said further set in series with one of said circuits while retaining said resistance in said circuit, and further means to connect together two of said signaling circuits and said further set in series and excluding said resistances of said connected circuits.

9. In a printing telegraph exchange, a plurality of-signaling circuits each comprising a resistance,

a plurality of jack contacts, a line conductor and:

a telegraph station set, a further telegraph station set, switching means to connect said further through said jack contacts and excluding said resistances of said connected circuits by operation of further jack contacts.

JOHN O. CARR'