US2260524A

US2260524A - Telephone system

Info

Publication number: US2260524A
Application number: US146356A
Authority: US
Inventors: Ralph E Hersey
Original assignee: Bell Telephone Laboratories Inc
Current assignee: AT&T Corp
Priority date: 1937-06-04
Filing date: 1937-06-04
Publication date: 1941-10-28
Anticipated expiration: 1958-10-28

Description

Oct. 28, 1941. R' EI HERSEY 260,524

TELEPHONE SYSTEM :usr rows /NVEA/ro@ Ef HERSEV BV www? A TTnD Ek Oct. 28, 1941. R. E. HERsEY 2,260,524

TELEPHONE SYSTEM Filed June 4, 1957 2A Sheecs--Sheer1 2 FIG. 2

\ II/00 A Faun/zen l I l: I

` A Top/v y Patented Oct. 28, 1941 TELEPHONE SYSTEM Ralph E. Hersey,

Telephone Madison, N. J., assigner to Bell Laboratories, Incorporated, New

York, N. Y., a corporation of New York Application June 4, 1937, Serial No. 146,356

(C1. 17eisi 8 Claims.

The invention relates to telephone systems and particularly to improvements in signaling arrangements for such systems.

An object of the invention is to simplify and reduce the cost of the equipments for ringing subscribers on called'lines.

Another object of the invention is to provide ringing means that does not require the usual ringing currentl supply nor ringing tripping equipment at the central oiiice.

the circuits for ringing the bell will not function as'the talking battery connections have previously been reversed and are maintained reversed until the connection is released at the central office. The normal battery andV ground connections for a subscribers line through the usual line relay is of such polarity that the subscribers bell Heretofore systems have been provided in 1 which ringing current applied at the central office causes the operation of ringing apparatus at a subscribers station and when the subscriber answers the call by removing his receiver from the switchhook, ra tripping relay at the central f office is operated to discontinue the application of ringing current. In certain systems, for example in case of party line `selective ringing systems, cold cathode gas-filled tubes of the trigger type have been scribers telephone sets. In these latter systems, a tube breaks down in response to ringing current to close a connection for a ringing circuit to ring a particular bell depending on the method of Wiring. l

A feature of the present invention is to provide a ringing and tripping arrangement for substation signaling in which the usual machine ringing equipment at the central oflice is eliminated and whereby a bell at the substation may be rung merely by closing the connection for the subscribers line from the talking battery 'at the central office.

It is a special feature of the applicants invention to employ a gas-filled tube at the substation for this purpose. This tube is in seriesvwith a bell winding and a resistance, and the tube and bell winding are shunted by a condenser. When a connection is established at the central cnice to thissubstation, the usual talking battery is applied on the line and the condenser is thereby charged until the tube breaks down, at which time the condenser discharges through the bell winding operating the bell, and the tube is then restored :to normal. The condenser is then again charged and these operations are repeated. The bell will therefore be tapped intermittently at intervals depending on the characteristics of the condenser and ithe breakdown potential of the tube. When the subscriber answers by removing his receiver from the switchhook, the circuits for the bell and resistance are made inoperative. The arrangement is such that when the called subscriber restores his receiver on the switchhook used in the various subwill not ring. lThe discharge tube is for these purposes polarized lto operate on currents in one direction only.

The-invention has been illustrated in 'the a'ccompanying drawings in which:

Fig. 1 shows the invention applied to an automatic step-by-step telephone system; and

Fig. 2 shows it applied to a manual telephone system.

Reference is now made to the drawings and particularly' to Fig. l, in which as much as 'is necessary to illustrateV applicants invention has been shown of an automatic step-by-step-system. Any standard automatic system may be employed using a connector such as is illustrated at C in this drawing'lwith the usual ringing source and tripping relay arrangement eliminated and otherwise arranged in accordance with the applicants invention. A calling subscribers line has been shown in diagrammatic form at l terminating in a line inder LF connected through any number of intermediate switches and a selector S having access to the connector C. This connector in turn `has access to a subscribers line 3 terminating in afcalled subscribers substation apparatus 4 arranged in accordance with the applicants invention.

A description will now be made of the operations When the substation 4 is called from the calling subscribers line l. The calling subscriber at I may connect throughthe line nder LF and intermediate switches to selector S which then finds the connector C in any manner well known in standard step-by-step systems. When the connector C has been found and connected to, a circuit is completed over the tip and ring conductors for the operation of relay 5 from battery and ground through the windings of this net 8 and relay 9 from battery through the Winding of this magnet, winding of relay .9, vertical off-normal contacts VON, contacts of relays 1 and 5 to ground. This causes the vertical magnet 8 to operate the connector switch C to take one vertical step. On the second release of relay 5, the circuit for the vertical magnet extends through thevfertical off-normal contacts VON and the armature and front contact of relay 9, which remains operated during the sending of the impulses of this digit, and the vertical magnet is operated to the desired `level depending on the number of pulses received. At

the end of this series of impulses relay.9,1 which Y.

is slow to release and remains operated# during this series of impulses, will release and' on the first impulse of the unit digit, a circuit vwill be Y completed for the rotary ymagnet I fron'bat# tery through the winding of this magnet; con` tacts of relays II, I2 land .9 andthe vertical off-normal contacts IVON, contacts offrelays I and to ground. It Vshould be noted that' a cirf cuitis also completed for relay I3 from'battery through the winding of this relay to ground at relay 5 over contacts of relays VI2 and 9,'contacts VON-and contacts of relays. 'I and 5. Relay I 3V operates alocking circuit for itself through its lower inner armature and vfront contact, to re` I9, contacts of the switchhook 20, resistance 2l, condenser I8, over the tip conductor, contacts of relays II and Il, lower winding of relay 6 to ground. The condenser I8 is lcharged in ac cordance with the potential of the battery through the windings of relay 6 and at a speed depending on the characteristics of the condenser and the resistance 2'I. .When charged to a value sucient to break down the gas-filled tube 22, the condenser will discharge over a pathy from the lower side of the condenser I8, winding of the tap bell 23, tube 22, to the upper side The tap bell 23 will operate of the condenser. to actuate its plunger to give a single tap to its gong. The tube will then be restored to normal and the condenser I8 will again be charged by the battery and ground through the windings of relay 6 and when suiciently charged cause lay 5 independent of the" contacts of relay I2.

Relay I3 is slow in releasing and remains oper-j ated during the dialing of the unit digit.l The rotaryrmagnet now advances the connector to, the desired subscribers line, in this case line 3.

If the -line is busy, there is a ground'on the sleeve terminal which would cause the oper-ation ,l of relay I2 before relay I3 releases over a circuit from battery through the winding of relay I2, contacts of relays II and I3, over the sleeve circuit to ground. Relay I2 is locked in oper` ated position on the release of relay I3 from battery through the winding of yrelay I2, contacts` of relay II make-beforefbreak contacts of relay I3, contacts of relay I2 to ground at the` sleeve from the selector S, as is well known. Re-

lay I2 appliesbusy tone from the source I5 over` the tip conductor back` to the calling` 'subscribers line at I.

vIn case, h'wever, Vthat `the 'called line -is idle, relay I3 will release afteran interval and a circuit will be -completed for the operation of Are- `I lay II from battery,` through the cut-off relay I6 over the sleeve circuit, contacts of relay I3,

upper winding of relay II,l contacts of relay I 2 to ground over the sleeve circuit 4from the selector s. Reny is now lockedthrough itsiower winding from battery through the rotary mag,-A

net I0, lower winding of relay II, its lower outer armature and front contact to` ground at contacts of relay 'I thus. putting ,the release of,this

connection undery control of the calling 5 subscribers line. ing of relay II prevents the operation of the 3 rotary magnet I0 at this time. 3 erating provides a ground for the sleeve `circuit .y and cut-off relay I6 and is held operated by this 1 ground overthe sleeve. Relay I I alsocloses at its two upper armatures and front contacts a 1 connection for thev tip and ring conductors to the called linev 3 from battery and ground 3 through the windings of -relay 6 and contacts of g relay I 1. j charged over a circuit from battery through the 1 upper Windingof relay 6,-' contacts of j relays'II 1 and vIIr over theV ring'conductor throughl the the right-hand winding of the repeating coil The resistance ofthe lower wind.-

Relayl `I I in opthe tube 22 to `again break down to operate the tap bell 23 a second time. These operations are continued at afrequency Adetermined' bythe characteristics 'of the resistance 2| and 'condenser I8and thebreakdown characteristics of the tube 22.'` The tap bel1'23/ will therefore continue tc ring its gong until the. subscriber answers by removing his receiverfrom the .switchhoolL In doing' this 'the charging 'circuit' through resistance '2| for the condenser I8 is opened and the rcondenser is short-circuited through the transmitter. and "consequently the ringinghwill cease. When the called subscriber at station 4 answers, rrelay 6 will' operatel and "reverse the battery and ground through the winding ofre lay 5over"the tip4 and ring conductorsftofthe callingv subscribers line yas a supervisoryzsignal and talkingl battery is now supplied for the calling subscribers line through the Winding lof, relay 5 and for the' called subscribers line through the winding of relayf.6 and the talking

connection overcondensers

25 and 26." f

When relay 6 operates it closes an obvious circuit'for relay I1 whichin operating locks itself to. groundv at relaylII and reverses the battery and ground connection over th'elwindingl of relay 6 for the. tip and ring conductors through the called line loop. ,y The gas-filled tubev 22 is "po larized and will not break down withbattery a'nd ground reversed. TheV tap bell is therefore preventedfrom ringing whenthe called subscriber replaces his rreceiver on the switchhook.- The calling subscriber when releasinghcauses.the re; leasof relay 5 which inturn releases'relaysl, II, Il and I6. "A circuitv is then closed'ffor 'ref lease magnet 2 from battery windingl of this magnetV contact VON, contacts of relaysv II",- .1 andh5,t o ground. It should'be noted'th'at whe relay `II releases the connectionV to v'the .substation from battery' and ground'over relay 6 is opened 'so relay I'I'may therefore be released to restore the polarity of the battery and ground to the tip and ring conductors vfor the next call.y The polarity `of the battery and ground through' line|64. In establishing this connection by 'int serting the plug H35 in the jackv I06,a circuit-is completed for the-'condenser lIIl'I from battery through-*the lower right-hand winding of the repeating coil |08, winding of the supervisory ofthe repeating coil |08to ground. This causes the `condenser |`|to be charged and when sufficiently charged it causes the tube ||4 to break ldown through the winding of the tap bell ||5 which taps `its gong once. These operations are then repeated until the ,subscriber at this stal tion answersfwhenithe ringing ceases and the talking circuit is completed. It should be observed that when the subscriber answered the supervisory relay |09 operates as'usual to extinguish the lamp I0 which lighted in the usual manner, when plug |05 was inserted in jack |06 over the sleeve circuit which circuitv also caused the operation of the cut-oli relay It should further be observed that the original circuit for lamp ||6 extends through the left-hand winding of relay ||0. This, however, did not cause relay ||0 to operate. On the other hand, when relay |00 operates, the shunting' circuit for lamp ||6 extinguishes the lamp and now extends through both windings of relay ||0 causing this relay to operate, The operation of relay ||0 opens the ring conductor but by that time the operation of relay |09 has already provided a substitute connection for this conductor so at this time no disconnection takes place. However, when the subscriber at |03 replaces his receiver relay |09 releases which opens the ring conductor and consequently prevents battery and ground through the right-hand windings of the repeating coil |08 from charging the condenser |01 and start ringing of the bell ||5 at this time, as relay ||0 will be maintained operated over the sleeve circuit, through its left-hand winding to prevent the ring conductor from being closed by the contacts of this relay. The characteristics of relay ||0 are such that it will not operate on current thro-ugh its left-hand winding, but after once operated by current through both windings, current through the left-hand winding will maintain its operated. The supervisory lamp ||6 now lights as a disconnect signal and the operator removes the plug |05 from jack |00, whereupon relays ||0 and are released and lamp ||6 extinguished. Relay restores the connection for the line |04 to battery and ground, through the windings of the line relay but the polarity of the battery and ground connection for this relay is such that the tube ||4 will not operate.

What is claimed is:

1. In a telephone system, a central oflice, a subscribers station, a line connecting said ofce and station, a source of talking current connecti able to said line at said central office, a ringer at said station having a winding and circuit means at said station including a gasi"1lled discharge tube connected to said winding and operative in response to the continuous iiow of current from s aid source over said line for producing an intermittent current through said winding for tile corresponding intermittent operation of said ringer.

2. In a telephone system, a central office, a subscribers station, a line connecting said ofice and station, a source of talking current connectable to said line at said central oflice, a ringer having a winding at said station, circuit means at said station connected to said winding and said line and including a network and a gaslled discharge tube operative in response to the continuous ow of current from said source when said source is connected to the line for producing an intermittent current through said winding to operate the ringer` at intervals.

3. In a telephone system, a central oiice, a subscribers station, a line connecting said oiiice and station, a source of talking current connectable to said line at said central oice, a condenser and a resistance in a series connection in said line at said station, a gas-filled discharge tube having a denite breakdown potential and -a .direct current ringer in a circuit in vshunt of said condenser, said condenser, resistance, tube and ringer being so adjusted that on the connection of the talking battery to the line at the central ofce the tube is caused to discharge at intervals for the operation of the ringer once for each discharge.

4. In a telephone system, a central oflice, a subscribers station, a line connecting said oflice and station, a source of talking current connectable to said line at said central oice, a condenser and a resistance in a series connection in said line at said station, a gas-lled discharge tube having a definite breakdown potential and a direct current ringer in a circuit in shunt of said condenser, said condenser, resistance, tube and ringer being so adjusted that on the connection of the talking battery to the line at the central onice the tube is caused to discharge at intervals for the operation of the ringer once for each discharge, and means for disabling the circuit for the discharge tube in response to the subscriber removing his receiver from its switchhook.

5. In a telephone system, a central oiiice, a subscribers station, a line connecting said office and station, a source of talking current connectable to said line at said central ofiice, a

condenser and a resistance in a series connection in said line at said station, a gas-lled discharge tube having a definite breakdown potential and a direct current ringer in a circuit in shunt of said condenser, said condenser, resistance, tube and ringer being so adjusted that on the connection of the talking battery to the line at the central office the tube is caused to discharge at intervals for the operation of the ringer once for each discharge, and means responsive to the subscriber removing his receiver from its switchhook for opening the connection for the resistance and short-circuiting the discharge tube, the ringer and the condenser.

6. In a telephone system, a central cnice, a subscribers station, a line comprising two line conductors connecting said office and station, a source of talking current connectable to said line at said central oflice, a ringer at said station comprising a winding, a plunger and a gong, the plunger being operated to strike the gong each time the winding is energized, a gasiilled discharge tube, and a condenser at said station, a circuit means for normally connecting said winding and said discharge tube in series across the two conductorsA of said line and the condenser in shunt of said winding and discharge tube, said winding, tube and condenser being responsive to continuous now o current from said source for alternately charging the condenser and discharging it across said tube in said winding to energize said winding to intermittently operate the armature to strike the gong.

'7. In a telephone system, a central oflice, a subscribers station, a line connecting said oflice and station, a sourcev of talking current connectablevto said line at said central office, a ringer comprising a gong, an armature and an operatingv Winding, Va condenser'charged in responsefto the continuousflowof current in said line, and means effective at intervals for discharging said condenser through said Winding -to deliver thereto impulses of current to operate said armature. t

8. In a telephone system, a central cnice, a telephone station, a linev connecting said cen- .tral oice andstation,Y a. source of direct f curtrent connectalole to said line at said central oflo said signal device for each measured interval.

RALPH E. HERSEY.