US1819685A - Telephone system - Google Patents

Telephone system Download PDF

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Publication number
US1819685A
US1819685A US418380A US41838030A US1819685A US 1819685 A US1819685 A US 1819685A US 418380 A US418380 A US 418380A US 41838030 A US41838030 A US 41838030A US 1819685 A US1819685 A US 1819685A
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United States
Prior art keywords
line
relay
selector
circuit
lines
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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US418380A
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English (en)
Inventor
Lundell Torsten Adil
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Telefonaktiebolaget LM Ericsson AB
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Telefonaktiebolaget LM Ericsson AB
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Filing date
Publication date
Application filed by Telefonaktiebolaget LM Ericsson AB filed Critical Telefonaktiebolaget LM Ericsson AB
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Publication of US1819685A publication Critical patent/US1819685A/en
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Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M3/00—Automatic or semi-automatic exchanges
    • H04M3/40—Applications of speech amplifiers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q3/00—Selecting arrangements
    • H04Q3/42—Circuit arrangements for indirect selecting controlled by common circuits, e.g. register controller, marker

Definitions

  • the inter-oifice communications are provided with repeaters or amplifiers disposed in the through-trafiic exchange.
  • the invention has for its. object to simplify the manual operation of such plants by replacing as far as possible manual operation by automatic operation.
  • the local operators positions otherwise used in inter-ofiice plants having through-trafiic are replaced by an automatic exchange over which the connections in question may be established through the intermedium or" the trunk or inter-ofiice operator which thus alone mediates the establishment and the supervision of the inter-oilice communica tions.
  • Figure 1 is a diagrammatic representation of a plant according to the invention adapted to establish amplified throughcommunications.
  • Figures 21,3, 4 and 5 are circuit diagrams for a plant according to Fig ure 1.
  • Figures 2 and 3 illustrate the arrangements in the manually operated position whereas Figures 4 and 5 show the parts of a talking connection extending through the automatic exchange.
  • Figure 6 is a circuit diagram for the final selector.
  • Figure 7 indicates the manner of combining Figures 2, 3, 4 and 5 to form a coherent circuit diagram.
  • each line in reality comprises two or more wires.
  • the figure shows two inter-ofiice lines 1L IL entering the telephone exchange which lines are connected to separate operators positions EP and EP respectively over normally closed contacts of the switching relay R11 by means of which the lines may be switched into direct communicationwith the automatic telephone exchange.
  • the operators positions EP are provided with devices to prepare the establishment of another communication over an inter-oflice line during a conversation going on at the time being.
  • each inter-office line in the operators position may alternately be connected to the one or the other of two appertaining auxiliary lines UL and UL which at the other end are connected to the automatic exchange.
  • the connection of the inter-oifice line to the auxiliary lines takes place over a switch WVO and two speaking switches E0 E0
  • the operators positions are provided with the necessary signalling devices to supervise the connections and numeral switching devices to establish the connections over the automatic exchange.
  • the latter devices may, by way of example, consist of a finger disk or dial or a set of buttons of the kind used in semi-automatic telephone systems.
  • the automatic exchange comprises distributing selectors in the form of call finders and also final selectors Lv LV
  • the auxiliary lines UL UL are connected in multiple to the contact fields of the call finders whereas the inter-ofii'ce lines are connected in multiple to the contact. field of the line selector.
  • Final selectors LV and LV are two and two mutually interconnected through cord lines SL in which repeater sets FA are included and over which the interoffice communications are completed by associating the one final selector LV in a, set of two selectors with the calling line and by associating the other final selector LV with a line extending in the wanted direction.
  • Each cord line is through an amplifier set and a line KL connected to a call finder AS over which a connection may be established to the operators positon to set the final selectors and to supervise the connection.
  • line extensions LF and line balances B, Figure 3 are applied in a manner known per se which balances according to the invention are adapted to be connected to the lines by means of the same selectors Lv LV through which the connections are established.
  • the inter-office lines and their appertaining line balances are then assumed to be connected to the difnott sections in the contact field of the final selector in such a manner that the terminals of the lines and the balances in the corresponding sections take up the same relative positions.
  • the final selectors LV LV are thus provided with two sets of contact fields KS KS disposed on the same movable switching member, Figure 5, of which the contact sets KS bring about the connection to the line and its testing wire over the line extension LF whereas the contact set KS serves to connect up the line balance B.
  • the system operates as follows. Upon a call being received in the operators position El? over the inter-office line 1L a call relay IE is actuated over a circuit 1 which relay in turn closes a circuit 2 through a call lamp IL and a relay FR which connects itself into a holding circuit and opens the circuit 1. The operator then shifts the speaking switch E0 to speaking position a speaking circuit 3 being then closed through the operators set comprising the telephone receiver T and the microphone M.
  • the interofiice line 1L is marked as engaged by a circuit 4 being closed through a relay RL which at its normally closed contact 5 disconnect-s the one of two rela s ltL RL associated in parallel with the testing wire 0 in such a manner that the resistance included between the testing wires and the negative terminal of the battery is increased to a corresponding degree.
  • she operates initially a switch Bli through which the testing wire of the auxiliary line UL is connected to the ne ative terminal of the battery over a contact 6. Thereupon the operator actuates a switch SK representing that exchange to which or over which the desired communication is to be established.
  • the line UL is marked as being calling in the group of call finders AS, the appertaining final selectors L3 of which may be connected to the lines extending to said exchange.
  • the latter marking is effected by associating a fourth conductor (Z common to a group of auxiliary lines UL with the negative terminal of the battery over a contact 7 of the switch SE
  • Said line cl is connected to a contact bar Kcl appertaining to:
  • Each call finder is provided with a set of c0n-- tacts comprising tour contact springs Fa, F6, F0 and F (Z. During the turning motion of the call finders the contact spring FcZ successively contacts with the contact bars Kd of the difierent contact rows.
  • a current path 10 is closed through a relay RS which is energized andconnectsitselt' into a holding circuit over its contact 11.
  • Said relay RS closes in a manner not shown here a circuit through the clutch magnet S0 of the sequence switch SOS, whereby the sequence switch is brought to its third position.
  • the circuit of the clutch magnet S0 is controlled in a manner known per se by a centering device CK which holds the circuit of the clutch magnet closed until the sequence switch has been accurz tely set in the correct position.
  • a circuit 12 In the third position of the sequence switch a circuit 12 is closed, whereby the relay LGR is short circuited and de-energized. Thereby all the call finders are brought to stop. That call finder which initially made contact with the contact bar Kd is, however, now started in radial direction to search the line UL marked as being calling. hen the call finder finds this line, a circuit 13 is closed containing a relay BR which opens the circuits 8 and 12 whereby the selector is brought to stop. At the same time the clutch magnetot the sequence switch SOS receives a new current impulse whereby the sequence switch is shifted to the fourth position. In this position a circuit '14 is closed for a relay RS which is energized and connects a speaking line to the register RE.
  • a circuit 20 is closed through a relay RV of the final selector.
  • the sequence switch SOV of the final selector is brought to its second position in which the final selector is started.
  • back impulses are sent over a current path 21 which impulses in known manner control a back impulse relay BB of the register RE.
  • a circuit of the relay HR of the register is opened, the relay BV being then de-energized.
  • the sequence switch SOV is now brought to its third position. In this position the circuit 20 is again closed the sequence switch being then shifted to its fourth position in which the selector performs its radial motion.
  • back impulses are sent over the circuit 22 through the relay RR in the register.
  • the relay RR is again operated, the circuit 20 being then again opened and RV then dropping its armature.
  • sequence switch SOV is then brought to its ninth position.
  • sequence switch SOS is brought to its ninth position, which is the speaking position.
  • an interoffice line may be marked as engaged in two different manners.
  • the line is namely marked as engaged in a certain manner when the line is engaged only by an existing talking connection and in another manner when besides another selector is associated with a line and standing by ready to connect itself to the line as soon as said line becomes free.
  • the sequence switch SOV stops in the ninth position as is readily understood by Figure 6. In this position a buzzer circuit 23 is closed through a winding of the relay RV Said buzzer current induces a current in the operative winding of the relay which current passes through a circuit 24: including the operators set.
  • the latter relay is now operated by the impulses sent over the circuit 25 whereby the circuit for a signalling lamp IL is alternately opened and closed at a contact 26 of said relay. Said lamp shows thus an unsteady light so long as the line still is engaged.
  • SOV proceeds to its eleventh position which is the speaking position. Then the circuit 25 is opened and the lamp IL is put out.
  • the cord line SL has now over the selector LV been associated with the inter-office fob line IL entering the operators position E1
  • the sequence switch SOS is brought to its sixth position in which the final selector LV is set in similar manner on that inter-office 1116 line, by way of example 1L with which communication is wanted.
  • the sequence switch SOS is brought to its ninth position which is the speaking position.
  • the operator is connected over the lines UL and KL to a set of relays belonging to the repeater FA said set comprising a relay RF which is now energized over a current path 82.
  • a circuit 35 is closed including a differential coil of the relay RL which so counteracts the previously energized operative winding of the same relay that the relay is de-energized, the inter-office line 1L being then again associated with the operators position.
  • the operator may now listen directly to both lines and send call signals.
  • the switch R0 is actuated.
  • circuit 37 is closed including a relay RF which connects 1L to a cal bell current source.
  • the repeater may be of any arbitrary kind and consists substantially of two amplification devices F F and two difierential transformers DT DT A clearing signal from the one or the other line operates a relay 11F or R1 respectively which in turn closes a circuit 40 through a coil of the relay RF which then connects its holding coil into a circuit ll. which also includes the relay RF The latter relay is, however, not energized in this case.
  • the relay 1R of the operators position is actuated which relay over its contact 26 connects the signalling lamp 1L into circuit.
  • the operator may now by shifting her speaking switch E0, in the above described manner put herself into communication with both lines. Finally the automatic connection is interrupted by restoration of the switch BK to normal position.
  • the final selector has to choose between a plurality of lines extending to the same exchange and the selector will for this reason upon being set on the first of the lines extending to the exchange in question, automatically search a line free for the time being.
  • the system is, according to the invention, so arranged that in case all outgoing lines should be engaged the selector is set in a stop position immediately after the contacts of the last line whereupon the selector returns over the same contacts while testing the lines anew. In said position the testing circuit of the selector has, however, been shifted in such a manner that the selector during its return motion may be set on a line engaged for the time being without establishing communication with said line.
  • the magnet GRV is energized over the contact 50 in the sequence switch a circuit 51 being then closed through the magnet MVV which causes a reversing of the motion of theselector, the selector now moving backward in the same contact row.
  • the relay RG is deenergized whereby the test wire is connected to a testing relay RG
  • the latter relay is so dimensioned that it may attract its armature even if the line, for the time being, is engaged by a communication. On the other hand, it may not attract its armature if the line is engaged by a communication and at the same time another selector is associated with the line in ready position.
  • the c-wire of the line is namely connected both to the negative terminal of the battery over a relay ItL if the line is engaged by a communication passing through the own operators position, and to the positive terminal of the battery over a relay RG in a selector in ready position. If the line should not be engaged in the own operators position the test wire of the line is connected to the positive pole of the battery over two parallel-connected relays RG In both cases.
  • the current received by the testing relay RG is insuflicient to operate the relay and the selector continues its motion until it finds either a line which in the meantime has become entirely free or a line which is engaged and on which no selector is set in ready position. Should all the lines during the return motion be marked as entirely engaged, i. e. if the selector is set in ready position on each one of the lines the selector continues its return motion until it reaches the stop position S immediately in front of the first position. In said position the relays RG and RG obtain sufficient current to be actuated the sequence switch being then operated over a circuit 52 and, as a consequence, brought to its ninth position in which position the selector stops and a busy signal is sent to the operator.
  • the relay RG is sufiiciently energized over the test wire to be able to attract its armature the sequence switch then receiving current over a circuit 53 and thereby being brought to its tenthposition in which position the selector remains standing by in ready position until the line becomes free.
  • the circuit 48 is interrupted and the relay HG,L consequently de-energized.
  • the relay RG has thus now been disconnected and instead the testing relay RG has been asso ciated with the test wire.
  • the relay RG attracts its armature which results in that the sequence switch is brought to its eleventh position which is the speaking position.
  • I claim: 1. A switching arrangement to establish inter-ofiice transit or throughecommunications betweenthe lines entering a telephone exchange from other telephone exchanges and more especially inter-ofiice communications having repeaters or amplifiers, characterized in that said lines are associated in multiple with final selectors which are two and two mutually interconnected through cord lines in which amplifiers may be included and over, which the inter-office commun cations line and the other line selector to a line eX- tending in the wanted direction, said cord lines being adapted to be connected over distributing selectors to auxiliaryor supervisory linesv extending from the inter-ofiice operators, positions over which lines the selectors may be operated and the intenoffice communications supervised.
  • each selector pair is provided with a sequence switching device whereby the switching is controlled in such a manner that the junction line is initially connected in turn to the two selectors to set said selectors and thereupon connected to the amplifier to control the communication.
  • a switching arrangement as claimed in claim 1 characterized by an arrangement to switch the testing circuit of those line selectors which establish communication with a wanted line said switching arrangement when all lines extending in the wanted direction are engaged, bringing about such an alteration in the testing circuit that the selector may be set in ready position on an engaged line without establishing communication therewith.
  • a switching arrangment as claimed in claim 1 characterized in that the calling line is adapted to be associated alternately to the inter-ofice operators position and to the final selector multiple by means of a switch arrangement adapted to be controlled by the operators position, said switching arrangement being adapted to be operated from the operators position of the supervisory line.
  • a switching arrangement as claimed in claim 1 characterized by an arrangement to switch the testing circuit of those line selectors which establish communication with a wanted line, said switching arrangement, when all lines extending in the wanted direction are engaged, bringing about such an alteration in the testing circuit that the selector may be set in ready position on an engaged line without establishing communication therein, the disposition of the selector being such that the selector when searching a wanted line, passes such lines in which an other selector already is set in ready position.
  • a switching arrangement as claimed in claim 1 characterized by an arrangement to switch the testing circuit of those line selectors which establish communication with a wanted line, said switching arrangement,

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  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Monitoring And Testing Of Exchanges (AREA)
  • Structure Of Telephone Exchanges (AREA)
US418380A 1929-01-12 1930-01-03 Telephone system Expired - Lifetime US1819685A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE1819685X 1929-01-12

Publications (1)

Publication Number Publication Date
US1819685A true US1819685A (en) 1931-08-18

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Family Applications (1)

Application Number Title Priority Date Filing Date
US418380A Expired - Lifetime US1819685A (en) 1929-01-12 1930-01-03 Telephone system

Country Status (4)

Country Link
US (1) US1819685A (enrdf_load_stackoverflow)
BE (1) BE366860A (enrdf_load_stackoverflow)
FR (1) FR687997A (enrdf_load_stackoverflow)
GB (1) GB360354A (enrdf_load_stackoverflow)

Also Published As

Publication number Publication date
GB360354A (en) 1931-10-22
BE366860A (enrdf_load_stackoverflow) 1930-02-28
FR687997A (fr) 1930-08-18

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