US2349990A - Connection for teleprinters - Google Patents

Description

May' 30, v1944- E. RossBERG 2,349,990

CONNECTION Fon TELEPRINTERS Filed Sept. 20, 1940 [He/14120 Rossana@ www/@4M r ha attorney.

Patented May 30, 1944 CONNECTION FOR TELEPRINTERS Ehrhard Rossberg, Berlin- Siemensstadt, Ger-- many; vested in the Alien Property Custodian Application September 20, 1940, Serial No. 357,533 In Germany September 25, 1939 y (ci. 17a- 2) 1o claims.

and a resistor is preferablyemployed. The lockingr-magnets may be provided withv holding wind- Aings-so that they remain energized during operation.

Further details of` the invention will be ap- 'v parent from the following description taken in H connection with-the, accompanying drawings, in

which i Fig. 1 shows the arrangement of the pawls and A' magnets;

Fig. 2 is av diagrammatic circuit drawing showing the-essential'parts of the system; and

Fig. 3 is a similar` drawing showing somewhat simpliiied circuits.

In the stateof rest the magnets Spi and Sp2 and the signal lamps KLI and KL2 are deenerl gized. Each magnet prevents its associated receiver shaft from rotating even whenv the receiver magnet receives the startingA impulse. Only upon the` energization of the magnet Spi or Sp2 is the corresponding receiver shaft permitted i to rotate by withdrawal -of the pawls KI, or Klz, respectively, in order to translate the signals received.

In Fig. 2 is shown the switching system for the operation of the apparatus. If, for instance, a call is received over the line LI, the calling relay ARI is released in accordance with the calling impulse which consists in an interruption of current. The contact ari is released to the position shown so that the condenser CI discharges through the resistance Ri As soon as the starting impulse ceases, the current flows through the line Li so that the armature of the relay ARI is again attracted. The condenser CI is charged over a circuit through the winding I of the magr net Spi, which circuit is as follows: earth, condenser CI, contact an, magnet Spi, battery, earth. The locking magnet attracts its armature so that the shaft EWI (Fig. 1) may begin to rotate and the conta-ot spia. is closed. In this manner a holding circuit is established through Athe winding II of the magnetv Spi, extending from earth, by way oi contactspia, magnet SpIII, quenching key'LTi, and battery to earth. l The signal lamp KLI, which indicates that the Ieceiver withv the magnet EMI (Fig. 2) andthe shaft EWI (Fig. 1) is in operation over the line LI, is inserted in the circuitin parallel relation to the circuit just traced. Upon the operation of the magnet Spi the motor M is connected to the current supply circuit N through the contact spit. The receiving magnet EMI can now receive the signals incoming over the line LI. The transmitting contact sk is arranged in the circuit in accordance rwith the position of the double-throw switch Ui Over the line Li a twoway working may therefore be effected with the aid of the receiving magnet EMI and the transmitting contact sk. Over the line L2, howevenonly reception may be effected at this time, in view of the position of the change-over switch U2.4

A` call arriving over the line L2 acts in a corresponding manner through the relays ARZ and the locking magnet Sp2. If two-way workingis to be eifected the. directional switches Ui and U2, which may under certain circumstances be combined in one switch, must be switched' over in a corresponding manner. A call over the line Li or L2 extending to theremote station takes place after changing over the'directional switch to the corresponding position by depressing the key RT. The closed circuit current is thus Vinterrupted in theline, the remote apparatus is started in the` manner as described above `and also the relay ARI or ARZ is released at the home station sothatthe apparatus is allowed torundown.

If the resistance RI is not of the same magnitude in the calling and called apparatus it may occur that the home apparatus starts, but the remote apparatus does not start at the remote station, because the calling impulse was too short. For this reason auxiliary resistors R2 are in `addition provided which are short-circuited through the contacts RTI and RT2 of the calling key. If the calling key is therefore depressed the time constant of the circuit Ci, RI is increased by the resistances R2 so that the calling impulse must be transmitted somewhat longer in order to start the ho-me apparatus, thus ensuring a starting of the remote apparatus.

In Fig. 3 the connection as shown in Fig. 2 is simpliiied. In this case only one calling relay AR is provided which, however, carries two windings. Besides only one combination consisting of a vcluding said transmitter, and a condenser and a resistor is provided. The relay AR is so wound that it is already released in the state of rest when current flows over the lines LI and L2 in the opposite direction in the two windings. However, during the operation the ar- -mature of the relay is attracted in response to the relatively short telegraphic impulses. The operation is eected in the same manner asr in Fig. 2. The relay AR is actuated in response to a call, for instance, through the winding II in the event of the line LI being deenergized. In this manner the condenser CI is discharged through the resistance W in order to transmit at the end of the starting impulse upon the` release of the relay AR an impulse through the magnet` FMI, winding I and the directional switch UI a. locking magnet FMI is attracted and remains energized through its contact fmia. The motor M is started through the contact fmib. Otherwise the operation is effected in the same mariner as in Fig. l2.

The connection may be simplified to a further extent if a .make and break contact is allotted to the receiving `magnet EMI or EMZ shown in Fig. 2 ory'3. This magnet has then the same function xas the contacts arl and am (Fig. 2) or ar (Fig. 3).

What is claimed is:

'1. In a printing telegraph system, a transmitter, two receivers, said transmitter and receivers being located at the same station, two lines incoming to said station and terminating in said receivers, respectively, circuit connections over which one line circuit is completed by way of its associated receiver and the said transmitter in i series, the other line circuit being completed by way of its associated receiver alone, and switching means for altering said circuit connections to include said transmitter in the second line circuit but not in the first.

2. In a printing telegraph system, two line circuits incoming to a telegraph station, two'reyceivers at said station connected in said line circuits, respectively, a transmitter at said station common to said line circuits, a connection from one line circuit extending through the associated receiver to said transmitter, a connection vfrom the second line circuit extending through the associated receiver to a source of current and exfor reversing said connections.

3. In al printing telegraph system, a line circuit adapted for two-way operation and including a receiver Vand a transmitter at the same end of the line, a second line circuit adapted for one- 'f" way operation only and including a. receiver, and a switching device for shifting the transmitter from the rst line circuit to the second, whereby switching device T' The charging said condenser in venting rotation of said shaft, a magnet for withdrawing saidpawl to start the receiver, a relay in said receiver responsive to an incoming call signal, gconderiser, and a circuit controlled by said relay fior charging said condenser in series with said magnet to energize the magnet.

6. A system as claimed in claim 5, wherein a locking circuit is provided for maintaining the magnet energized after the-condenser has become charged. w

7. In a, printing telegraph system, a receiver having a shaft, a pawl normally preventing rotation of said shaft, a magnet'fcr` withdrawing said pawl to start the'receiver, a relay' iny said receiver deenergized at the beginning of Ya call signal and energized at the end of such signal, a condenser, a circuit completed-by the deenergization of said relay for discharging said condenser at a predetermined rate, and a''circuit completed by the energization of said relay for series with said magnet to energize the same.

8. A printing telegraph system as set forth in claim 7, arranged for two-way 'transmission with receivers at opposite ends of a line circuit, said system being provided with signal transmitters associated with the" respective receivers, and .-means in each transmitter responsive to the o peration thereof for automatically decreasing the discharge rate of the condenser in the receiver at the same end of the line. v

9. lIn a printing telegraph system, t'wo receivers each having a 'shaft which is'n'ormally'preve'nted from rotation, magnets in's'aid receivers for releasing said shafts, lines incoming to said receivers, respectively, a differential relay 'having two windings included in said lines, respectively, and circuit connections over which said magnets are controlled by said relay;v v'

10. A printing telegraph system as set forth in claim'9, wherein a'manual switch is provided to operatively associate the differential relaywith either release magnet' at will. f

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