DE629521C - Circuit arrangement for telecommunication systems, in particular telephone extension systems - Google Patents

Description

GERMAN EMPIRE

ISSUED ON May 8, 1936

REICH PATENT OFFICE

PATENT LETTERING

JVi 629521 CLASS 21 a 3 GROUP 54oi

Patented in the German Empire on May 16, 1931

In telecommunications systems in which connections of different values are established, it may be necessary to disconnect an ordinary connection in favor of a preferred connection, namely when there is no longer a free connection path available for the preferred connection.
In such known systems, the originally existing connection path collapses after the compulsory disconnection, so that the subscribers who speak to one another first do not readily have the opportunity to continue their conversation after the preferred connection has been processed.

In private branch exchanges there is a possibility to restore the original connection take up, but so far only with the help of the officer. For example, if an official

ao spoke and the speaking extension subscriber is then requested by the remote exchange, so the officer can after the separation of the office connection the exchange line z. B. by turning over a so-called Waiting switch, through which a choke coil is switched on in the exchange line, hold until the long-distance call ends is. The officer can then restore the original connection.

However, this mode of operation requires a considerable amount of attention and work ahead of the officer.

The purpose of the present invention is to reduce the inconvenience in such systems in operation. and unnecessary waiting times due to inattentive operation to avoid. This is achieved according to the invention in that after the forced disconnection the dialers of the usual connection path and the test relay remain set of the voter who is on the line of claiming the preferred connection called subscriber, responds after termination of the preferred connection, to reconnect the original connection.

In themselves are arrangements in which the voters are set after a forced separation stay known. In the known systems, an officer had the opportunity to during the existence of a connection according to the upstream principle directly into the Cut the subscriber line by putting their query switch in the working position brought. The one used for the existing connection and assigned to the subscriber line Voters remained set. When the switch was put back, the connection of the interrogation apparatus of the officer with the participant line and

*) The patent seeker stated as the inventor:

Robert Helmert in Berlin-Lichterfelde.

at the same time the. .original connection switched through again. With this order too, the resumption took place as 0 .. of the original connection not automatically, but under the influence of a Switching action by the officer.

In the figure, an embodiment of the invention is shown for a private branch exchange. ίο It is assumed that the extension subscriber T _{1 is} connected to an exchange line (line i) via a line selector LW. During the exchange call, the subscriber should be asked by the remote exchange which connection is made via line 2. The line 2 is otherwise connected in exactly the same way as line 1, which is why the essential switching means are only included in the figure for the latter line. To facilitate the overview, only the necessary to \ ^r fore sub ject of the inventive concept means are shown.

The following describes first the establishment of the exchange connection with the subscriber T ₁ , then the activation of the preferred connection, the separation of the original exchange connection and the automatic resumption of the original connection.

The private branch exchange is called over trunk 1 by an alternating current surge which energizes relay AR . The latter is linked via its contact Cf ₁ and the query switch A ₁ . The AL call lamp is also switched on via the% contact. The officer now asks by flipping the query switch. Your set is connected to the exchange line via contacts. ^ ₂ and A ₃ . The winding I of the relay U is switched on by the contact A ₁ , so that this relay responds. The contact ^ switches the rotary magnet DLW of the line selector to the number switch NU . The contact A _e prevents premature checking the relay P. Due to the contact A _1, the relay AR is de-energized, so that the contact Ci ₁ opens and the ^To: AL call lamp goes out. To do this, the UL monitoring lamp is switched on via contacts U ₂ and 4T ₁ . In a known manner, the officer sets the line selector to the line of subscriber T ₁ , who is requested from the office, by actuating the number switch NU. After this activity, the officer puts the interrogation switch A back in the rest position. Here, the winding I of the relay U is de-energized. However, this relay is held in the following way about his winding II: earth, release button Tr, U II, U ₁₃ brush LW _it V _1, A _5, DLW, battery, earth. If the subscriber T _{1 is} free, the relay P responds via the closed contact A ₆ : earth, A ₆ , u _s , windings of the relay P, subscriber relay T, battery, earth. The relay P blocks the line in a known manner by switching over the contact P ₁ . The busy lamp BL is switched on by the contact p ₂ , so that the officer is made aware of the call status by the simultaneous lighting of the two lamps UL and BL . The call current is sent to the subscriber station T ₁ in the following way: earth, call machine RM, C I, p "v. _2l LW ₂ , T ₁ , LW ₁ , v » /> ₄ , C II, battery, earth. When the subscriber reports and thereby closes a direct current path, the relay C in the direct current path, protected by a copper jacket against responding to alternating current, responds in a known manner. The contact C ₁ closes a circuit for the relay /: earth, X I, / I, C ₁ , resistance Wi, / II, battery, earth. The relay X is designed as a differential relay so that it does not respond. The relay V is switched on via the contact i'i: earth, x ₂ , I ₁ , V, battery, earth. When relay V responds _, the line leading to the subscriber is switched from relay C to relay / via contacts V ₂ and v a. Relay C drops out, but relay / remains after opening contact C ₁ above the subscriber loop. The contact V ₁ opens the circuit for the winding II of the relay U, so that the latter drops. The contact V ₁ applies ground to the brush 3 of the line selector LW, so that the blocking is maintained and the relay P drops out. Due to the contact? ^, The busy lamp BL remains switched on after the contact p ₂ is opened. However, the UL monitoring lamp goes out due to the opening of contact M ₂ . After the% contact has been opened, the exchange line is held via the v _e contact.

The speaking currents flow through the capacitors C ₁ , C ₂ . The subscriber T ₁ is fed via the relays X and /. The trunk line is held through the reactor Dr. xio

If the subscriber T ₁ is now requested by the remote office, which reaches the switching center via a second line line 2, the following processes take place: The officer puts the line selector LWy of the second connection path, via which the preferred connection is established, on the line of subscriber T ₁ . By pressing the AT button, earth is connected to line α . As a result, the differential relay X responds via its winding II and remains on the contact

bars χ _Ά and U ₅ . The monitoring lamp UL is connected to the flicker interrupter FU via the contact X ₁ , so that it flickers. Contact x ₂ opens the circuit for relay V. The latter drops out. At the contact w ₄ , the blocking of the line of the subscriber T _{1 is} canceled so that the relay Pb of the line 2 can respond. The exchange line will continue to be held via contact x ± . The connection between subscriber and exchange line is canceled by the contacts, · ^ and v _a.

The officer recognizes by the flickering of the lamp UL on which exchange line the subscriber T _{1 has} spoken and can now enter this line by flicking the switch ^ in order to notify the subscriber connected to the office of the compulsory disconnection due to the long-distance call and to give him / her ask if he wishes to resume the original connection. In this case, the query switch is simply put back in the rest position, and the exchange line is held via contact ti ₄ . The relay U was in fact energized again via its winding I when the interrogation switch was flipped and remains in the circuit described above via the brush 4 of the line selector LW when the interrogation switch is moved back via its contact U _1. Of course, the re-energization of the relay U can also take place automatically when the relay X is triggered, if the officer is also to be released from notifying the public servant.

After the termination of the preferred connection, the line of subscriber T ₁ is free again, so that now completely self-

4.0 active, the relay P of line 1 responds again in the test circuit closed _{via contact W 3.} The following processes: calling, reporting the subscriber and connecting line I to the subscriber are carried out exactly as described above for the call via line 1.

If the automatic through-connection of the exchange line to subscriber T _{1 is} to be prevented after the remote connection has been terminated because the interrogated subscriber does not want to reestablish the connection, the button Tr is pressed after the interrogation switch of line 1 has been put back, whereby the relay U drops out and the Connection triggers in a known manner. The tripping circuit for the line selector is as follows: earth, breaker Ub, contact x ₅ , U ₁ , LWi, V ₁ , A ₅ , DLW, battery, earth.

The invention is not limited to the illustrated embodiment. If, for example, a normal connection, as seen by the subscriber T ₁ , is established in the outgoing direction, the preselection device via which the outgoing connection was established is held while the preferred connection is being processed.

Claims (2)

Patent claims: 1. Switching arrangement for telecommunications systems, in particular telephone private branch exchanges, in which ordinary connections running through voters are forcibly disconnected in favor of preferred connections, characterized in that after the forced disconnection, the voters of the normal connection path remain set in a manner known per se and the test relay (P) of the Voter who is on the line of the subscriber (T ₁ ) used for the preferred connection responds to the termination of the preferred connection in order to connect the original connection again. 2. Switching arrangement according to claim i, characterized in that the automatic switching through of the connection after the forced disconnection can be suppressed by a switching means (Tr) arranged on the operator station causing the forced disconnection. For this purpose I sheet drawings