DE611929C - Circuit arrangement for telephone systems in which the participants can make connections in two traffic directions themselves - Google Patents

Description

GERMAN EMPIRE

ISSUED ON APRIL 9, 1935

REICH PATENT OFFICE

PATENT LETTERING

CLASS 21a ³ GROUP 28

Siemens & Halske Akt.-Ges. in Berlin-Siemensstadt *)

Patented in the German Empire on August 21, 1931

In the telephone system !! with automatically outgoing traffic in two directions (e.g. public and house traffic) it happens that all lines of a traffic direction are occupied are. If now, in this case, a call station establishes a connection via a line wants to establish this traffic direction, it has the switching measure, which is necessary, to determine the direction of traffic alone, i.e. to adjust the direction selector accordingly, made in vain, since it only recognizes after completion of this switching measure that no line is free. The fact that all lines of a traffic direction are busy, in particular of all trunk lines of a private branch exchange, is particularly in the case of small systems with a few

'' Trunk lines extremely disruptive, so that facilities have already been provided for this case, which means that all trunk lines of the

Show ao extension before connection. These are e.g. indicators on the microphone units, which respond when the trunk lines are busy.

Such facilities have the disadvantage that you have to use a double line the microphone units do not get along and that the

. Participant machines must be specially trained. They are therefore also a hindrance to Conversion of existing systems and the relocation of microphone units.

All these disadvantages are avoided according to the invention in that all of the outgoing lines of a traffic direction, reachable via direction selector, of the subscriber in the handset an acoustic signal receives before he carries out the switching measures to influence the direction selector.

In the case of automatic systems, it is common to provide a so-called official sign, which, when you lift the handset, indicates that dialing can begin. By Change of this official symbol one now has a simple and operationally reliable means to the If necessary, subscribers can simultaneously indicate that all trunk lines are busy.

If, for example, an interrupted rattle tone is chosen as the official signal, then it could you put a high-pitched buzzer on the line during the breaks to make it clear afterwards indicate that while voting can begin, one trunk is at the moment but is not available. Another possibility would be instead of the rattle mark provide a low buzzer tone for all trunk lines to be busy so that

*) The patent seeker stated as the inventor:

Hans Tatzl in Vienna.

: βιι 9 ^ 9

also because of this, a clear sign is created. An exemplary embodiment of the invention is shown in the drawing.

Lifts z. B. the subscriber N from his receiver, the following circuit is established for the relay R : earth, contact Ii via the subscriber N, contact 2t, relay R, battery, earth. The relay R switches on the drive magnet, not shown, of the preselector in a known manner, so that it is moved forward step by step until a free group selector GW is found. In this case the following circuit occurs: earth, battery, windings I and II of relay T, contact 3r, switching arm c of preselector FPF, resistor Wi, winding I of relay C, head contact 4A, earth. Relays T and C respond in this circuit. Through relay T the subscriber line is switched through once by opening the contacts xt and 2 t and closing the contacts 5 t and 6t , while winding II of the relay T is short-circuited by closing the contact Jt and thus the occupied group selector GPF is blocked in a known manner . Furthermore, the rotary magnet of the preselector is stopped by relay T, but this is not shown.

Assume that at the time the connection is made, an outside line, e.g. B. the trunk AL, is still free. In this case the relay G is energized via earth ,, relay & ,, contacts 25 er, 29 h, resistor W and thus contact gg is open,

If contact 8 c is now closed by the above-mentioned relay C , only the buzzer 5 U is switched on to winding III of relay A when the contact xouk closes by an interrupter contact uk, which is actuated in a known manner in certain time periods, which transmits the buzzer to the windings I or II of the relay 4 inductively.

The participant thus receives the signal that the election can be started. He operates his number switch and thereby sends out current surges in a known manner. The relay A, which was energized after switching through the contacts 5i and 6t via the subscriber loop, is caused to drop out according to the interruptions at the subscriber station, so that the lifting magnet H is actuated via the following path: Earth, contacts 12c, 13 « , Winding I of relay V, solenoid H, battery, earth. During the series of impulses, relay F is energized and ver * ·. thus prevents actuation of the rotary magnet D by opening the contact 14 ν , in whose excitation circuit the contact 15 k is closed after the first stroke step of the selector GW . The contact 4k is opened at the first stroke of the selector GW , so that fihvReläisC via winding II of the relay C and contact 16c, a new test circuit is established.

If the relay F drops out after the end of the series of impulses, the rotary magnet is excited via: earth, contact xq-p, head contact 15 k, contact 14W, rotary magnet D, battery, earth. The rotary magnet D causes the group selector GW to advance by one step and, at the same time, to close the contact 17 d. This contact excites the relay V via winding II and interrupts the circuit of the rotary magnet D at contact 14 ». This in turn interrupts the circuit for relay F at contact τη &. The contact 14 a is closed again and the rotary magnet D is energized again. This cooperation between relay F and rotary magnet D continues until the group selector GW z. B. has found a free exchange line, because then via: earth, contact 18 c, windings I and II of relay P, switching arm c of group selector GW, relay CR, battery, earth the relay P is energized, and at contact 19 ^ the Circuit of the rotary magnet D is interrupted. By shorting the winding I at the contact 20 ^> the trunk line is blocked in a known manner, by opening the contacts 2Xf and 22ji> and closing the contacts 23 ^ and 24 ^ the line in the group selector GW is switched through. Relay CR sets the parallel path for the relay !? via the contacts of 25, 29 h, resistance W, battery, earth at contact 25 he interrupted.

The further establishment of the connection and the release of the connection after the end of the Conversation take place in a familiar manner.

In the case of incoming exchange connections via the exchange line AL , the relay H influences the relay G in the following way: The relay AR is energized by the ringing current arriving from the exchange, which energizes the relay H by closing the contact 26 ar . By closing the contact 27 h ' , a holding circuit for the relay if via: earth, isolating contacts 28 tk, 27h, relay E, battery, earth is closed. Furthermore, the call lamp AL is made to light up parallel to the relay H. By opening the contact 29 h , the parallel path for the relay G is interrupted as before with outgoing connections through the contact 25 er.

A relay CR and a relay H are now provided for each exchange line, which separate the parallel circuits of the relay G for outgoing or incoming exchange connections. In the drawing, only the circuit of the relay G for three trunk lines AL, AL ₁ and AL _{x is} indicated,

If no trunk is free, there is excitement of relay G not possible because either

with established outgoing exchange connection through the relay Ci? or in the case of incoming connections through the relay H, the various parallel circuits for the relay C are interrupted.

In this case, if a subscriber lifts his handset and occupies a free group selector GW in the manner described, then by closing the contact iTuk during the breaks

ίο of the character originating from the buzzer SU , which is switched on when the contact io «& is closed, also _{transmits the character generated by the buzzer SiJ 1} to the subscriber in a known manner.

If the buzzer SU now generates a low buzzer tone and the buzzer SiJ ₁ a high buzzer tone, the subscriber receives a clear signal from which he recognizes that the dialing can be started, but on the other hand an exchange line is not available at the moment.

Claims (3)

Patent claims: i. Circuit arrangement for telephone systems, in particular private branch exchanges, in which the subscribers can establish connections in two traffic directions (branch exchange - office) themselves, characterized in that when all outgoing lines of a traffic direction (office) accessible via direction dials are busy, switching means (relay G) are activated, by means of which an acoustic signal is transmitted to the subscriber before the switching measures to be carried out in the receiver to influence the direction selector. 2. Circuit arrangement according to claim 1 for systems in which the subscriber after Lifting the handset receives an acoustic signal by which it recognizes that with the Dialing can begin · (exchange signal), characterized in that when the line is busy of all office managements the sign that calls for the beginning of the election, in a clearer way Way is changed. 3. Circuit arrangement according to claim 1, characterized in that when it is busy the lines of one traffic direction alternate between the public signal and a busy signal is switched on. For this purpose ι sheet of drawings