US2111615A - Signaling system - Google Patents

Description

Mmh 22, 193s.

W. W. CRAMER SIGrIULINGv SYSTEM Filed May 18, 1937 /Nvg/vron W W CRAMER A T TORNE V Patented Mar. 22, 1938 yuNiTED STATES PATENT 'OFFICE SIGNALING SYSTEM Application May 18, 1937, Serial'No. 143,248

5 Claims.

This invention relates to signaling systemsand particularly to telegraph systems arranged for transmitting and receiving polarized signals.

It is an object of the invention to provide a simple, efcient and reliable conference circuit for interconnection of three or more signaling ,stations in a polar telegraph system.

Y This invention is a telegraph repeater circuit comprising a polarized receiving relay and a polarized sending relay for each of a plurality lof branches, one winding of each of the sending relays being connected in series in a local circuit, the other winding of each sending relay being normally short-circuited by contacts of the associated receiving relay. Operation `of any receiving relay reverses the current in the series circuit to operate all of the sending relays eX- cept the one associated with the operated receiving relay, operation of .the last-mentioned sending relay being prevented by current through its normally short-circuited winding.

The invention will be further described by considering the conference circuit shown inv the drawing which forms a part of this specification. The invention is, however, not limited in -its application tothe specic arrangement shown but is applicable to any polar telegraph system 1n which conference circuits or multiline repeaters are provided.

Referring to the drawing:

Fig. 1 shows schematically three telegraph stations I0, 2and 30, three cords I4, 24 and 34 for use in interconnecting stations for communication, and a conference circuit C comprising jacks I5l 25 and 35, receiving relays I1, -21 and 31, sending relays I8, 28 and 38, and a common control relay 9; and

Fig. 2 shows a cord circuit CD of a type suitable for use with the conference circuit C.

The kconference circuit C is arranged for interconnecting only three stations but may be arranged for interconnecting more than three stations by providing another jack and set of relays' for each additional branch of the circuit. The

' switchboard, at which the conference circuit C is provided, is shownV as a manually operated board, but the manually operated equipment can, of course, be replaced by automatic switching equipment. Each of the double-ended cords shown schematically in Fig. l are used for interconnecting subscribers loops and interoice trunks as Well as for establishing conference connections. Polarized repeating relays are provided in each ofthe cords as shown in Fig. 2. The operators positions may be equipped with,

teletypewriter equipment for communicating with subscribers and other operators, and the subscribersstations may `be similarly equipped for communicating with operators and other subscribers. For a more complete description of such a system reference may be had to the copending application of G. A. Locke'et al. Serial No. 459,684, led June 7, 1930. The line jacks i3, 23 and 33 and conference circuit jacks I5, 25 and 35 may be multipled to a plurality of positions. A busy lamp BL is associated with the rst jack of the conference circuit at each position to which the conference jacks are multipled.

Assume that an operator has received a request for the interconnection of stations I, 20

and 30, and that the desired interconnection is provided by plugging one end of cord I4 into jack I3 and the other end into jack I5,V by plugging one end of cord 24 into jack 23 and the other end into jack 25 and by plugging one end of cord 34 into jack 33 and the other end into jack 35. The sleeve relays I6, 26 and 36 associated with jacks I5, 25 and 35 are thereby operated; and each of these relays closes a circuit for operating the common control relay 9. Each of the operated sleeve relays opens a normally closed short circuit around the lower winding of the associated sending relay, which short circuit is independent 4of the associated receiving relay, and substitutes a short circuit which is under control of the as- I sociated receiving relay. With common relay 9 operated, a circuit is closed from negative battery 8 through the right front contact of relay 9, normally closed contact of relay 31, and front contact of relay 36, normally closed contact of relay ,f

V21 and front contact of relay 26, normally closed contact of relay I1 and front contact of relay I5, upper winding of relay I8, upper winding of relay 28 and upper winding of relay 38 to ground through the left front Contact of relay 9. The current in this circuit is eiective to hold the armatures of relays I8, 28 and 38 on the marking contact as shown in the drawing. The biasing winding of each of the receiving relays I1, 21 and -31 is energized in a circuit from negative battery at the normally closed contact of the'associated sending relay to ground at the upper front contact of the associated sleeve relay; and the upper -windings of receiving relays I1, 21 and 31 are energized in circuits from negative battery at the normally closed contact of the associated sending relay, through the tip conductors of the associatedione of jacks I5, 25 and 35, through the winding of one repeating relay and contact of the other repeating relay in the associated cord,

to positive battery. The current through the windings of receiving relays I1, 21 and 31 holds the armatures of these relays on their marking contacts as shown in the drawing.

When any one of the interconnected stations starts sending a message, the signals are repeated through the cord to the associated receiving relay of the conference circuit and operation of any one of the receiving relays causes the operation of all of the sending relays except the one associated with the operated receiving relay, the signal from the sending station being thereby repeated through the other cords to all other interconnected stations. For instance, assume that the station IIl' is sending. The signals are repeated through the cord to the receiving relay I1. A spacing signal moves the armature of relay I1 to its spacing contact and a marking signa moves the armature of relay I1 to its marking contact. When the armature of relay I1 moves from its marking to its spacing contact, the upper winding of relay I8 is disconnected from negative battery 8 and connected to positive battery 1 thereby causing a reversal of the energization of the upper windings of relays I8, 28 and 38. The armatures of sending relays 28 and 38 are thereby moved to their spacing contacts, sending a spacing signal to and through cords 24 and 34 to stations 20 and 30. The operation of receiving relay I1 opens the short circuit around the lower winding of sending relay I8 and the resulting energization of this winding opposes the reversed energization of the upper winding and is effective to maintain the armature of relay I8 on its marking contact. When relay I1 next responds to a marking signal, the energization of the upper windings of relays I8, 28 and 38 is again reversed and the armatures of relays 28 and 38 move to their marking positions thus sending a marking signal to stations 28 and 3U. The operation of either of receiving relay `21 or 31 when station 28 or 38 is sending a message causes a similar signal repeating operation. If one or more branches of the conference circuit are not used in any given conference connection, the associated sleeve relay will not be operated and operation of its sending relay is, of course, without effect.

When the plugs are removed from jacks I5, 25 and 35, sleeve relays I5, 26 and 3G release.

Patching cords may be used to interconnect the subscribers jacks with the conference circuit, but in this case the conference circuit is modied so that positive battery is connected to the marking contact and negative battery to the spacing contact of each of the sending relays of the conference circuit.

What is claimed is:

1. In a telegraph system, subscribers stations, a conference circuit, and means includingl said conference circuit for interconnecting a plurality cf said stations, said conference circuit comprising a receiving relay and a sending relay for each interconnected station, the operating winding of each of said sending relays being connected in a series circuit and the holding Winding of each of said sending relays being normally short-circuited by contacts of the associated receiving relay, the operation of any one of the receiving relays being effective to reverse the current in said series circuit and to open said short circuit around the holding Winding of the associated sending relay.

2. In a telegraph system, subscribers stations, a conference circuit having a plurality 0l branches, means for connecting a plurality of said stations to said conference circuit, a polarized signal receiving relay and a polarized signal sending relay for each of said branches, a series circuit for energizing one Winding of each of said sending relays, circuits each including another winding of said sending relays, and contacts for each of said receiving relays for reversing the current in said series circuit.

3. In a telegraph system, subscribers stations, a conference circuit having a plurality of branches, means for connecting a plurality of said stations to said conference circuit, a polarized signal receiving relay and a polarized signal sending relay for each of said branches, an operating winding and a biasing winding for each of said sending relays, a series circuit for energizing the operating winding of each of said sending relays, and contacts for each of said receiving relays for reversing the current in said series crcuit and for opening and closing a short circuit around the biasing winding of the associated sending relay.

4. In combination in a telegraph system., a plurality of signaling circuits, a repeater having a plurality of branches, means for connecting each branch to a different signaling circuit, a pair of polarized sending and receiving relays for each of said branches, means comprising contact springs of each of said receiving relays for energizing one winding of each of said sending re- :m-

lays in series, said contact springs of each of said receiving relays also being eiective to shortcircuit the other winding of the associated sending relay, and means comprising another contact of each receiving relay for reversing the current in the series connected windings of said sending relays and for energizing said other Winding of the associated sending relay.

5. In combination in a telegraph system, a

plurality of pairs of polarized sending and receiving relays, a plurality of signaling circuits, each pair of sending and receiving relays being connected to receive signals from and send signals to a diiTerent one of said signaling circuits, means comprising contacts of each of said receiving relays for energizing one winding of each of said sending relays in series, said contacts of each of said receiving relays also being effective to open and close a short circuit around another winding of the associated sending relay, and other contacts of each of said receiving relays for reversing the current in the series connected windings of said sending relays and for energizing said other winding of the associated sending relay.

WALTER W. GRANIER.

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