DE1046108B - Circuit arrangement for telephone extension systems - Google Patents

Description

GERMAN

In private telephone exchange systems, special switching devices are often made available to preferred subscribers, which the production of special connections to individual call stations of the private branch exchange, bypassing the switching equipment enable the private branch exchange. The special switching devices are used to establish the desired connection after actuation a marking button and thereby the impulse transmission, which is used to establish connections in private branch exchanges is usually required to bypass. Triggering a Such a connection established via this special switching facility requires a switching measure of the preferred participant. Since the special switching facilities usually also for Establishing consultation calls while the preferred intercom is switched on If an exchange line is used, the trigger action must be based on the triggering of the special switch let restrict. Make the special switching means previously provided for this the operation of the intercom of a preferred participant is confusing, so that incorrect connections can easily be made be made. The aim of the invention is to avoid such incorrect connections and to improve the operation to keep the intercom as simple as possible.

This object is achieved by the invention in a circuit arrangement for telephone private branch exchanges, with which preferred subscribers special switching equipment for the establishment of special connections to individual call stations, bypassing the switchboard of the private branch exchange are available and where a Rüclrquageschaltmittel at each preferred subscriber station is provided, through the actuation of which queries are initiated or triggered by the fact that the holding circuits of the switching means of the special switching device controlling the triggering of a special connection are under the influence of the inquiry switching means of the preferred subscriber station. In private branch exchange systems have the Call stations as inquiry switching means a button, which both before establishing an inquiry connection as well as to be activated temporarily to terminate it. The invention now pulls this button to trigger the special switching facility. When terminating an over the special switching facility Established connection, the preferred intercom unit only has to carry out the same switching action that would otherwise be used for Termination of a consultation connection established in the private branch exchange is to be carried out.

Circuit arrangement
for telephone exchange systems

Applicant:

Telefonbau and Normalzeit GmbH,
Frankfurt / M., Mainzer Landstr. 134-146

Friedel Bopp, Bad Vilbel (Hess.),
has been named as the inventor

Preferred call stations of this type are often also equipped with auxiliary devices to facilitate the Equipped with a current impulse when establishing connections. These pushbutton controlled surge transmitters have switching means which, when actuated, delete each one beforehand by pressing a key cause caused adjustment of storage means and the like. According to a further training the invention is now achieved a further simplification in that one Switching means of the surge sending device causing erasure of each memory setting under the influence of the inquiry switching means of the preferred subscriber station.

An embodiment of the invention is shown in the drawing. This gives schematically the essential switching means and connection options of a preferred intercom in a telephone exchange again.

The switching device NV of the private branch exchange is used to connect the connected subscribers (TN, Γ 4 ... Γ16) to one another or to connect them to a free exchange line (ALI, AL2). The design of such switching devices controllable under the influence of current surges is known and is therefore not shown in detail in the drawing. Such switching devices have a switching device tu in the transmission assigned to an exchange line, which is switched over during the existence of an exchange connection by temporarily pressing an ET earth button in the intercom station, so that a connection can be established with the subsequent power impulse to a subscriber station Inquiry is to be held, and when this inquiry is terminated by temporarily pressing the earth button, it is restored to its original

809 698/89

initial position is reset in which the connection between the calling subscriber station and the exchange line AL 1, AL2 exists.

The connection establishment between the individual subscriber stations (TN, T 4 ... T16) is controlled by power surges. Depending on the size of the private branch exchange, one, two or three series of current impulses must be sent out, for which purpose a rotary dial is usually used on the intercom.

The preferred speech station TN has a special switching device SV available which contains a selector W which is set in motion by actuation of a marking key ST and which is set to the subscriber identified by this marking key. If, for example, the marking key ST 4 is actuated, a relay B is energized, which sets the selector in motion in a manner not shown. As soon as the switch arm Wb of the selector meets the contact marked by the marking button, a circuit for the winding I of a relay A and U is established . Contact a2 closes a circuit for the lamp LA on the intercom of the preferred subscriber. This circuit is controlled by a contact p of a test relay, not shown, which responds when the designated subscriber T 4 is free. When this subscriber is busy, the lamp LA is controlled in the rhythm of a busy pulse generator BK, and when it is free in the rhythm of a call pulse generator RK . The subscriber TN therefore immediately recognizes from the way the lamp lights up that the connection to the desired subscriber T4t has been established and whether this subscriber is busy or is being called.

The relay U has switched over in the connecting line TLN , so that the telephone station TN of the preferred subscriber is connected to the feed relay 6 "of the special switching facility SV . As soon as the called subscriber T 4 picks up, the feed relay Y is energized and switches with the contact y 1 through the connection. The subscriber T 4 of the private branch exchange NV is thus occupied and called by the special switching facility SV , bypassing the connecting facility NV , for which the preferred intercom station only needs to press the marking button ST 4 assigned to this subscriber until the lamp LA lights up. When the relay U is energized, a bridge is placed on the connecting line TLN in a known manner, not shown, so that a previously established connection to an exchange line ALI, AL2 is maintained.

To trigger the connection established via the special switching facility, the preferred location must temporarily press the subscriber key ET , which is also used to terminate inquiry connections that are set up in the private branch exchange. On the rest side of an additional contact ET2 of the subscriber key, a holding circuit for the winding Π of the relay A is interrupted, so that it drops out and thus also the circuit of the switch relay U interrupts.

The working side of the additional contact ET2 closes a circuit for the extinguishing switching means (extinguishing relay L) of a current impulse transmission device ZG, which enables the preferred intercom TN to transmit 9 decadic series of current impulses by a transmitter S by pressing the number keys ZTl ... ZT . The numerical value assigned to each number key ZT is recorded in a known manner in a memory SP ; All numerical values stored in rapid succession are picked up one after the other by a transmitter and transmitted in the form of a series of current impulses to the pulse line TLI , which is connected to the connection line TLN of the preferred intercom. The impulse transmission device ZG can also contain a special memory ZP , in which a multi-digit call number is immediately identified when a ZIT key is pressed, the individual values of which are then sent out one after the other by the transmitter S over the line TLI . The storage of the numerical values in the memories SP and ZP is dependent on a contact / extinguishing relay L. If this extinguishing relay L is actuated, the storage is deleted and no more series of current pulses can be transmitted by the transmitter * 9. Deletion is necessary so that if you make a mistake in choosing the key, the transmission of power surges can be stopped immediately. For the actuation of this extinguishing switching means L a special key is avoided by the fact that the working side of the contact ET 2 of the earth button of the preferred call station provided for switching on inquiry and canceling it closes the circuit of the extinguishing switching means.

Claims (2)

Patent claims: 1.Circuit arrangement for telephone private branch exchanges, in which preferred subscribers have special switching devices available for establishing special connections to individual telephone stations bypassing the switching devices of the private branch exchange and in which an inquiry switching means is provided at each preferred subscriber station, by the actuation of which inquiries are initiated or triggered, thereby characterized in that the holding circuits of the switching means (A, E, U) of the special switching device (SV) controlling the triggering of a special connection are under the influence of the inquiry switching means (ET) of the preferred subscriber station (TN) . 2. Circuit arrangement according to claim 1, in which the preferred subscriber station has special rush current transmission devices available, characterized in that the switching means (L) of the rush current transmission device (ZG) which causes deletion of each memory setting is under the influence of the inquiry switching means (ET) of the preferred subscriber station . 1 sheet of drawings © 809 698/89 12.58