US2307855A - Telephone system - Google Patents

Telephone system Download PDF

Info

Publication number
US2307855A
US2307855A US391643A US39164341A US2307855A US 2307855 A US2307855 A US 2307855A US 391643 A US391643 A US 391643A US 39164341 A US39164341 A US 39164341A US 2307855 A US2307855 A US 2307855A
Authority
US
United States
Prior art keywords
line
relay
station
exchange
switch
Prior art date
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
Application number
US391643A
Other languages
English (en)
Inventor
Pearce Owen Avis
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.)
Associated Telephone and Telegraph Co
Original Assignee
Associated Telephone and Telegraph Co
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Associated Telephone and Telegraph Co filed Critical Associated Telephone and Telegraph Co
Application granted granted Critical
Publication of US2307855A publication Critical patent/US2307855A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q3/00—Selecting arrangements

Definitions

  • TELEPHONE SYSTEM Filed may s, 1941 s sheets-sheet 2 INVENTOR OWEN Avls Pz-:ARCE
  • the present invention relates to telephone systems and is more particularly concerned with systems in which a group of subscribers is served for both incoming and outgoing calls by a single two-conductor line extending to the exchange.
  • the chief object of the invention is to provide an improved multi-party line system of this type in Which improved arrangements are made to maintain and to supervise the service to the group of subscribers involved.
  • each subscribers equipment in a telephone system including party lines arranged so that only one party at a time can connect his equipment to the line, each subscribers equipment includes a device adapted to be operated in response to a controlling action at the exchange to disconnect the said equipment from the line.
  • the impulses in a telephone system including party lines arranged so that the connection of any subscribers equipment to the line for either an incoming or an outgoing call is dependent upon the transmission of impulses from the exchange, the impulses also serve to effect the stepping of a switch at the exchange the circuit for bringing this switch to rest when the required number of impulses have been transmitted extending over a wiper of the switch to enable a portion to be individual to the various stations so that service to particular stations may be denied by interrupting the corresponding individual portion.
  • the impulse responsive switches at the substations are set to a characteristic position in which no station is connected up and a switch in the exchange which in synchronism with the substation switches is set to a corresponding position in which it initiates the giving yof an alarm.
  • Fig. 3 discloses the equipment of only one of the subscribers, for instance subscriber No. 4.
  • Each party line group is assumed to comprise up to ten subscribers, each of which requires apparatus including two neon tube gas discharge devices NTA and N'I'B, two step-by-step electromagnetically-operated 12-position switches F and C and a relay PGR which is provided with a mechanical latch so that it will lock in its operated position.
  • apparatus including two neon tube gas discharge devices NTA and N'I'B, two step-by-step electromagnetically-operated 12-position switches F and C and a relay PGR which is provided with a mechanical latch so that it will lock in its operated position.
  • each subscriber will also be provided with an automatic telephone instrument the circuit of which is also shown in Fig. 3.
  • each party line group is provided with a switching unit, the circuits of which are shown in Figs. 1 and 2, which unit is introduced between the party line and the usual line and cut-01T relay assembly and includes a 25-position reverse-drive electromagneticallyoperated stepping switch which serves to count or control the impulses transmitted on calls between the main exchange and the group of subscribers.
  • the party line system to be described is suitable for use in connection with either a manual or an automatic exchange, provides secrecy of communication and quality of transmission substantially equal to that of ordinary individual line subscribers, and gives individual metering of outgoing calls. Provision is also made for local intercommunication between the subscribers of a group.
  • the general arrangements are similar to those of the system disclosed in United States Patent No. 2,180,963.
  • the switch hook contacts SHI complete a loop across the negative and positive leads to the main exchange.
  • a circuit is then completed from earth, wiper SI, Fig. 2 in position 1, armatures 0113 and ic3, left-hand high resistance winding of relay ST, armatures rfi, sr3, pg2, to2, M3 and ctll, negative conductor of the party line, armature pgrl in the calling station, off-normal contacts F(N) of switch off-normal contacts C(N)2 of switch C, rectifier MRE in a conductive direction, winding of relay PGR, contacts SHI, resistance I8, positive line, armatures ct, pri, sl, f2, pgS, right-hand winding of relay RF to battery.
  • relay ST Only relay ST operates in this circuit and locks up over its make rst armature stI and its right-hand winding, and at armature $152 operates relay ON, at armature sill busies the line to incoming calls and at armature S153, Fig. 1, applies earth to common lead I3 in order to start up a common pulse machine or pulsing relay, contacts of which will periodically loop the conductors I4 and I5, Fig. 2, at a rate of the order of three pulses per second.
  • the first looping of leads I4 and I5 operates relay PGA from earth connected over armatures ctt, ce2, srl, on2, oni, and st2.
  • relay PR releases and disconnects the high voltage pulse circuit and the circuit to the magnet SM whereupon the wipers of switch S are advanced to position 2.
  • Succeeding pulses operate cn relay PR in the manner described and high potential pulses which are counted by switch S are transmitted to all the party line subscribers equipments in parallel.
  • the neon tube NTA associated with each station in the group is caused to strike since the rectifier MRC in series therewith is in a conductive direction and current thereupon flows through the winding of each switch F which responds, the rectier mD in parallel therewith being non-conductive for current in thisdirection.
  • each F switch advances from the home position 1 to position 2 in which position the oit-normal springs are operated and at contacts F(N)I remove rectiier MRD from across the magnet winding, while contacts F(N)2 disconnect the calling loop from across the line. At the same time contacts F(N)2 of other subscribers switches prevent them looping the line if they attempt to originate a call.
  • Relay SZ at armature sel completes a locking circuit for itselfover wiper and bank S5 to battery connected to the negative line via thewinding of the line relay associated with the party line group, which relay now operates and at armature S22, Fig. 2, disconnects the earth feed to the impulsing ⁇ circuit for relay PR and releases relays PGA and .PG thereby stopping the transmission of pulses from the exchange to the party line.
  • Relay ST will have released when the S switch advanced from the home position l, but relay ON remains held over the wiper and bank SI.
  • the automatic main exchange is further assumed to be of a known type employing individual line switches and booster battery metering. Accordingly when relay SZ locks in series with the line relay, the operation of the latter will cause the rotary line switch to hunt for an idle rst selector.
  • Relay CT is connected across leads M and MI in parallel with the cut-ofi ⁇ relay, lead MI extending to the battery side of the cut-off relay,
  • relay CT is also operated.
  • the cut-.off relay and relay CT .thereupon extend the negative and positive party line leads through to the rst selector in preparation for receiving dialled digits in accordance with the wanted number.
  • Relay SZ is disconnected from the negative line at armature ctS and releases, and the impulse receivingrelay in the iirst selector is now operated from the calling partys loop.
  • Relay CT at armatures e154 and ct5 prepares .for'the sending out of further high potential 'pulses to the party line and at armature ct re-completes the pulsing circuit for relay PR.
  • Relays PGA and PG are operated as before and relay PR is then pulsed to extend further high potential negative pulses to the pcsitive line and at the same time to extend pulses f to the magnet SM of switch S.
  • the F switches at the various party line stations are stepped in -synchronism until they again reach the home position I when the contacts F(N)-I and F(N)2 will be restored to normal.
  • Rectier MRD will now be bridged across the winding of each F switch magnet and serves as a short-circuit during the break period between pulses, thereby holding the magnet operated to prevent the switches from being vstepped past this position.
  • the total number of pulses transmitted is at least equal to the maximum number required to home the F switches from any position, and sending out of these pulses is terminated when the wiper SI reaches either of the homing positions 13 or l according to whether the switch is working over the rst or secon-d half of the bank. Relays ON, PGA, PG and PR now restore and the various F switch magnets of the parties also restore and all subscribers equipments and the main -exchange equipment is now normal in readiness for further calls.
  • earth ⁇ is extended from the switching relay therein over a particular one of the private conductors PI-Pll, Fig. 2 in the nal selector multiple FSM according to the parl ticular party line subscriber being called, and this earth extends via bank and wiper S2 to operate relay IC.
  • this .relay at armature icl locks ⁇ independently ofwiper S2, disconnects the normal connection of the left-hand winding of relay ST to the line at armature lz'c2, completes an operating circuit for relay ST by way of its right-hand winding at armature z'c3, and at armature iclI applies earth to the P lead extending to the line switch circuit so as tooperate the cut-olf relay therein and so prevent the line relay from being energised and initiating the operation of the line switch.
  • Relay IC also at armature z'c prepares a circuit for relay CR and at armature ict disconnects any circuit for the meters M'IRI-M'IRIIl.
  • Relay ST as before locks over its armature stl, operates relay ON over its armature str vand at armature sts applies earth to the pulse machine start lead I3.
  • Relay ON connects earth over armatures str, onI, om, and c5 to operate relay CR which locks independently of relay IC ⁇ at its armature crI.
  • Relay CR also at armature 0T2 connects up over common lead I I a source of high potential positive to earth to the armature prI and at armature cr3 connects up the lower winding of relay SZ to the positive party line conductor.
  • Relay ON also at its armatures onl and 0112 extends earth to the pulsing circuit and relays PGA and PG operate as before, while relay PR is impulsed from the pulsing contacts connected to leads I4 and I5.
  • armature pri high potential positive pulses are now applied to the positive line, While at armature pf2 the switch magnet SM is operated in synchronism and the number of pulses applied to line will be adjusted as will be seen later in accordance with the particular subscriber required.
  • the rectier MRC will now be non-conductive and rectifier MRB conductive to these pulses so that the C switches will now respond to the high potential pulses applied.
  • the rst pulse transmitted steps both the S and C switches to position 2, while the next ten pulses step the C switches to the effective positions 3-12.
  • the number ofpulses transmitted is determined by wiper and bank S4, Fig. 1, in accordance with the particular subscriber being called. For instance, if No. 4 subscriber is being called, after a total of five pulses have been transmitted when the S andC switches will occupy position 6, wiper Sil will encounter battery potential from the ringing return battery in the iinal selector which connects with contact 6 in the Sil bank Via No. 4. positive conductor -of the party line group in the fina-l selectormultiple.
  • Relay SZ will thereupon operate over its lower winding and will stop the transmission of pulses as previously described.
  • Relay SZ also operates relay CT as before since the cut-off relay is ⁇ operated and relay CT at ar- 'matures ctll andctli connects No.4 partyA line positive conductor in the final selector multiple and the negative conductor common to the party line group in the nal selector multiple through to the party 'linewhereupon ringing current is extended via kthe nal selector ring trip relay and out over the negative conductor of the party line.
  • a plurality of positive pulses is now transmitted over the positive line to home the C switches and the S switch is also horned and controls the number vof homing pulses sent out in the manner describedv previously in connection 4with the F switches, after which all equipment is restored to normal in readiness for subsequent calls.
  • the C switch associated with the wanted party closes its contactsCl and C2 and thereby connects his earthed bell to the negative line.
  • the F switch associated with the calling subscriber will also have operated contacts FI and F2 and since his receiver is already restored, his bell also will be connected to the negative line.
  • the bells of both the -calling and called subscribers will thus be rung in parallel and when they reply, their telephones will be connected in parallel to the main exchange and conversation may proceed.
  • a resistance lil is included in the conversational circuit of each of the parties, and it will be understood that these resistances are adjusted so that the loop resistance offered by all parties approximates to 600 ohms .thereby ensuring that currents through the transmitters of the two parties under revertive call rconditions will be substantially equal.
  • a party line subscriber should remove his receiver but omit to dial, the selector taken into use originates an alarm via suitable delayed alarm equipment.
  • Arrangements are provided whereby the faulty station in question may be isolated or locked out from the common line in order that thi-s line may be restored to the service of the otherV stations thereon.
  • KPR is provided in the switching unit in the exchange and on being momentarily operated clears the faulty subscriber from the common line in the following manner. Ai contacts KPRI, Fig. 2, relay SR is operated, and this relay at armature ST2, Fig. 1, releases relay CT to clear the connection set up to the main exchange first selector.
  • relay SR commences to release slowly, and during its release time high voltage positive to earth is fed over common lead Il, key contacts KPR2 and armatures 3T3, pc2, 02, prt and cfJ on to the negative line, while an earth potential is fed over contacts KPRl and armatures ST4, pri and ctB on to the positive'line.
  • the so-called permanent glow relay PGR is connected across the lineby way of resistance lLswitch hook contacts SPILwinding of relay PGR, F switch contacts Fl, telephone instrument, F switch contacts F2 to the negative line and relay PGR is thereupon operated.
  • the neon tubes NTA and NTB do not tend to flash under this condition since they are short-circuited 'by the earth connected to the positive line at the main exchange.
  • relay PGR mechanically locks in the operated position by means of a suitable latching arrangement and at armature pgrl opens the start loop circuit.
  • relay SR On the release of relay SR the high voltage positive pulse source and the earth return are disconnected from theline and at armature srl an operating circuit is recompleted for relays PGA and PG and for the pulsing relay PR so as to initiate the homing of the switch S and the sending out of high voltage negative pulses in the usual manner to home the F switches.
  • the other nine parties on the line are now enabled to obtain service therefrom, but as regards the faulty party, it will be necessary for a maintenance ofcer to visit his premises and unlatch the relay before the service can be restored to him.
  • the relay PGR could be automatically unlatched as soon as the party replaced his receiver.
  • relay S'I operates by way of its left-hand winding in a series with relay RF as in the case ofthe origination of a normal call and after the rst pulse has been transmitted to line, in response to which all F switches will be stepped oiT-normal, a loop condition will still obtain on the party line, which condition only obtains in the case of contact between the party line conductors.
  • Relay SZ will Vtherefore operate to stop the pulse transmission in the usual manner and relay RF will be operated from earth, lower winding of relay SZ, armatures ciS, GT3 and sel, wiper S5 in position 2, .key contacts KRI, left-hand winding of relay RF to battery.
  • Relay RF at armature 'rfi disconnects the left-hand winding of relay ST from the line in order to render ineffective the origination of calls by any of the lparty line subscribers
  • at armature N2 completesa vlocking circuit for itself over its right-hand winding to earth via the release key contacts KR2
  • at armature 1'13 completes a circuit to light the line fault lamp LFL
  • at armature rf applies earth to common lead i6 so as to set into operation suitable delayed alarm equipment which will give analarm after a predetermined period
  • at armature H disconnects the incoming call circuit via relay IC.
  • relay'RF In the case of a fault earth on the positive line, relay'RF is directly operated over its rightliand winding and thereupon functions as already described, while in the case of a fault the release key RT whereupon at contacts KRI and KRZ the circuits for both windings of relay RF are disconnected and this relay thereupon releases. Ii the equipment has been stepped oinormal it is then horned in the usual manner.
  • each of the various subscribers stations on the party line could be provided with an indicator by means of which a visual busy indication could be given whenever the line was engaged.
  • the earthed switching equipment associated with each subscriber is connected to the positive line by way of neon tubes which in their non-conductive state during speaking conditions serve to isolate this equipment from the line thereby preventing the standard of speech transmission from being lowered.
  • an exchange a party line outgoing from said exchange, each station on said line having a start circuit'over which calls from-that station may be initiated and also having another circuit normally disconnected from said line, a'device at each station, means responsive to the initiation of a call over the start circuit at any station for disabling all of said start ⁇ circuits and connecting said other circuit at said calling station only to said line, said other circuitwhen connected to said line effective to render said device at the calling station only re" sponsive to signalling current of a certain character applied tosaid line, means at theexchange thereafter operated to apply signalling currents of said certain character to said .line to operate said responsive device, means controlled by said;
  • an exchange a party line outgoing from said exchange, each station on said party line having a first circuit normally disconnected from said line, a start circuit at each station, a device at each station normally connected to said line over the start circuit thereat, means at each station for transmitting a signal to the exchange over the start circuit at that station
  • a switch at each station controlled from the exchange responsive t said signal for opening a point in the start circuit at that station, thereby to disconnect said devices from said line, said switch at the calling station only also controlled from the exchange to connect said device to the line over said rst circuit at that station, means at the exchange for thereafter operating said device at the calling station over the line and said rst circuit at the calling station, means controlled by said device upon operation for opening another point in the start circuit at said calling station, and means in the exchange then operated for controlling saidv switches to close said first-named point in the start circuit at each of said stations.
  • a party line a plurality of stations on said line means controlled from any station for extending a call over said line, a start circuit for said means including a portion at each station, means at each station for completing the start circuit portion at that station, means for then disabling the portions at all stations, means for thereafter enabling the start circuit portions, and means at each station controlled over said line to prevent the enabling of any one 01 said portions.
  • a party line each station on said line having certain equipment thereat normally disconnected from said line, means operable to cause the equipment at any selected station to be connected to said line, a start circuit at each of said stations for initiating the operation of said means, means for at times disabling said start circuits at all of said stations concurrently, and means operated at other times causing the start circuit at some one of said stations to be disabled without causing the start circuits at the others of said stations to be disabled.
  • a party line extending to an exchange, a plurality of stations on said line, means at each station for initiating a call over said line and for locking out all other stations, and means controlled from the exchange over said line and operated whenever a certain station has initiated a call for locking out that particular station and restoring said locked out other stations.
  • a party line three or more stations on said line each normally having access to said line for calls, means for associating any one of said stations with said linev to permit that station to engage in a call and, during said call, barring the access of the others of said stations to said line, thereby to prevent said other stations from intruding upon said call, means for at times barring the access of said line of only one of said stations, when no other station on said line is engaged in a call.
  • an exchange In a telephone system, an exchange, a party line outgoing from said exchange, a register at the exchange operated whenever any station or said line initiates a call, thereby to register the identity of the calling station, and means automatically controlled by said register for permitting calls to be extended over said line, when same is free, only from a predetermined one or more of said stations.
  • an exchange a party line outgoing from said exchange, a plurality of stations on said line, means at the exchange for transmitting impulses over said line to select different ones of said stations at different times, a circuit at the exchange including a different portion for each station on said line, a contact in each of said portions operable in different ways independently of the contacts in the others of said portions, a switch at theexchange operated in synchronism with said impulses for rendering the diierent ones of said portions oi ,said circuit effective'in turn, a device in said circuit effective when operated to halt said operation ofsaid impulse transmitting means, and means for operating said device over said cirfor conditioning that station for a call only when said switch has been stepped to a predetermined oi-normal position, the different stations being conditioned at different off-normal positions o1 the respective switches, and means at the exchange responsive to an abnormal condition on said line for causing said rst means to operate said switches to an off-normal position in which no station on said line is

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Interface Circuits In Exchanges (AREA)
US391643A 1940-06-22 1941-05-03 Telephone system Expired - Lifetime US2307855A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB10748/40A GB542039A (en) 1940-06-22 1940-06-22 Improvements in or relating to telephone systems

Publications (1)

Publication Number Publication Date
US2307855A true US2307855A (en) 1943-01-12

Family

ID=9973553

Family Applications (1)

Application Number Title Priority Date Filing Date
US391643A Expired - Lifetime US2307855A (en) 1940-06-22 1941-05-03 Telephone system

Country Status (4)

Country Link
US (1) US2307855A (enrdf_load_stackoverflow)
BE (1) BE464871A (enrdf_load_stackoverflow)
FR (1) FR932189A (enrdf_load_stackoverflow)
GB (1) GB542039A (enrdf_load_stackoverflow)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2870263A (en) * 1955-02-25 1959-01-20 Gen Dynamics Corp Radio or carrier terminal dial selector
US2904633A (en) * 1954-08-06 1959-09-15 Gen Telephone Lab Inc Party line paystation
US2971085A (en) * 1956-06-22 1961-02-07 Automatic Elect Lab Selective signaling radiotelephone system
US3016426A (en) * 1957-10-04 1962-01-09 Bell Telephone Labor Inc Multiparty selective signaling system

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2904633A (en) * 1954-08-06 1959-09-15 Gen Telephone Lab Inc Party line paystation
US2870263A (en) * 1955-02-25 1959-01-20 Gen Dynamics Corp Radio or carrier terminal dial selector
US2971085A (en) * 1956-06-22 1961-02-07 Automatic Elect Lab Selective signaling radiotelephone system
US3016426A (en) * 1957-10-04 1962-01-09 Bell Telephone Labor Inc Multiparty selective signaling system

Also Published As

Publication number Publication date
GB542039A (en) 1941-12-23
FR932189A (fr) 1948-03-15
BE464871A (enrdf_load_stackoverflow)

Similar Documents

Publication Publication Date Title
US2245799A (en) Telephone system
US2307855A (en) Telephone system
US2592784A (en) Restricted service telephone system
US2335473A (en) Telephone system
US2180963A (en) Telephone system
US2717925A (en) Party line selective signalling system having code and conference call
US2386126A (en) Telephone system
US2262595A (en) Telephone system
US2820103A (en) Subscriber line concentrating system
US2609456A (en) Rotary out-trunk switching arrangement
US1791587A (en) Printing-telegraph system
US2543062A (en) Local battery party-line lockout system
US2339669A (en) Communication system
US2260524A (en) Telephone system
US2706747A (en) Selector repeater for telephone systems
US2208924A (en) Telephone system
US2162892A (en) Telephone system
US1812641A (en) Remote control magneto telephone system
US1689343A (en) Telephone system
US1474008A (en) Machine-switching telephone-exchange system
US2765367A (en) Time division multiplex multi-station per line telephone system
US2388136A (en) Party-line printing telegraph system
US1849087A (en) Telephone system
US1647256A (en) Selector-switch circuits for step-by-step systems
US1930921A (en) Telephone system