DE252511C - - Google Patents

Description

IMPERIAL

PATENT OFFICE.

PATENT LETTERING

CLASS 21 a. GROUP

in Hannover.

Addendum to patent 234687 from December 15, 1909.

Patented in the German Empire on October 19, 1911. Longest duration: December 14, 1924.

The patent 234687 provides a special circuit for switching points in private branch exchanges protected, which is characterized in that by means of a suitable delay mechanism the final Final signaling or the automatic release of the connection at the switchover point is delayed is, on the other hand, the final signal is given to the office immediately after attaching the extension handset, to Purposes to be able to give flicker signals after the office.

With this connection is an automatic disconnection of the connection after it has expired of the delay mechanism provided, it is necessary to ensure that this delay mechanism or the release magnet is only switched on when the extension requested by the exchange picks up the call, otherwise it would happen could that by the delay mechanism, which is used to output the flicker signals is used, the release magnet could also be switched on before the set is operated on the called extension will.

The officer at the switching point must therefore make sure that she pulls the trigger magnet or the timer does not switch on too early, otherwise the above-mentioned inconvenience, that the connection could be disconnected before the conversation begins.

The present invention now aims to eliminate this dependency of the delay relay or to remove the release magnet from the officer and to guarantee that these organisms are always switched on at the right time, and only when the called extension answers.

One embodiment is shown in the drawing. In the same, P, I, 0 means a line leading to the AmI, HA means an interrogation switch, with the help of which the officer can contact the exchange line P, I, 0 , η is a delay relay, which only after a certain time has elapsed a contact 1 closes.

As soon as contact 1 is closed, a tripping magnet AM is energized, which now initiates the automatic release of the connection or the automatic reset of the extension connection switch / 5 in a suitable manner. If z. B. a call arrives on the exchange line P, I, 0 , the call relay AR responds in a known manner and brings the call lamp AL to light up. The officer

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now turns the switch HA , finds out the number of the desired extension, turns the associated extension switch JS and calls the extension in a known manner. When switching the HA switch, a few other switchings are made in addition to switching on the officer's voice. So z. B. a current closed, from the negative pole via contact 2

ίο on switch HA, an auxiliary relay HR, contact 3 on switch HA to the positive pole. As a result, the relay HR attracts its armature and thereby opens a contact 4, which interrupts the circuit of the delay relay η. Simultaneously the auxiliary relay HR closes a contact 5 and thereby bridges the contact 2, so that the relay HR remains energized, even if ■ after the extension switch / S has been turned over, the office interrogation switch HA is put back by the officer. The current then flows from the negative pole via contact 5 on the auxiliary relay HR, the auxiliary relay HR, a contact 6 on the switch / S to the positive pole.

As soon as the called extension subscriber picks up his receiver, relay SR also receives power, from the negative pole of the battery via one winding of relay S R contact 7 on switch HA, extension switch / S, line g, subscriber station, line h, contact 10 on the switch / 5, contact 8 on switch HA and via the other winding of relay SR to the positive pole.

The relay S R attracts its armature, thereby opening a contact 11 and closing a contact 12. As a result, the auxiliary relay HR is short-circuited so that it drops its armature, interrupts its own circuit at contact 5 and closes a circuit at contact 4 of the delay relay η prepared. From this moment on, the relay η is only dependent on the relay 5 R, so that when the armature of relay 5 R has dropped a circuit from the negative pole of the battery via the contacts 11, 4 of the relays SR, HR, the delay relay η and the contact 6 at the switch / S to the positive pole of the battery. Η can now relay the final circuit signaling to the cabinet or the switching on of the trigger magnet to the delay, while according to the Office towards the end character R 5 is given in a known manner directly with the Stromloswerden the relay; in the present drawing z. B. in that a choke coil DP by breaking the contact 13 from the exchange line P ₁ I, 0 is switched off.

The implementation is of course not limited to the example given. Rather, z. B. the relay HR when the relay 5 R responds by breaking the circuit ineffective.

Claims (1)

Patent claim: Circuit to prevent premature disconnection of external calls by delay relays according to patent 234687, characterized in that the circuit (negative pole, 11, 4, n, 6, positive pole) of the delay relay (s) at the beginning of the conversation with the called extension (g, h) by their closing relay (SR) initially only prepared (in the exemplary embodiment of the drawing according to the powerlessness of an auxiliary relay (HR), which was placed on the battery when the exchange called by the office was reported) and is only closed when the extension has its remote receiver appends again, whereby the closing relay is de-energized, for the purpose of switching on the releasing of the connection (between P, i, 0 and g, h) causing delay relay (s) regardless of the time for the establishment of the desired connection by the exchange and do not let the delay relay run time become too long. ■ 1 sheet of drawings.