DE147467C - - Google Patents

Description

IMPERIAL Λ

PATENT OFFICE.

The telephone systems with line selector 'operation o. The like. Track for double line the purpose of preventing eavesdropping on conversations between two offices, which is caused by the well-known induction effect and current distribution. There are several ways to avoid this inconvenience Circuit devices become known. Most of these facilities

ίο content themselves with the fact that they are through special Circuits or devices prevent a third party from using their Line selector switches their speech device to the line line being used; in the The rest of the systems are based on the type of well-known line selector systems for single lines switched. However, practical experience has shown that with such Facilities an undesired switching is excluded, but still conversations from third parties are more or less overheard, since in the Lines the known induction effects occur.

. One is therefore for the purpose of not listening to the line dialer !! ο. like. more and more switched to pure dual-line operation. The conversations between two bodies are always only performed on the loop belonging to these positions and is even a third place impossible, a connection of the lines of your speaking apparatus respectively with the respective loop used. with the speaking sets of the other two.

The two wires that form the individual loops must often be crossed will.

A circuit arrangement for double-line line dialer operation is, for example, that where there are so many electromagnetic indicators in common at every intercom Wise arranged, connected as extensions in the line dialer system are.

The called station can see who called it from these indicators, and accordingly switches your speech set using your line dialer key on the lines leading to the calling station. So here it is the electromagnetic Indicators are required and a call can only be made after using the associated line selector key the called offices and only on two lines.

The one in English patent specification 5136 of the year 1900 described circuit is that in the patent Telephone system is carried out in the known manner of the single line dialer systems, such that the line lines of the individual call stations are branched off to the line selector of each call station. In order to avoid eavesdropping on conversations from unauthorized parties, except the above-mentioned line selectors and associated lines still have special switching devices arranged at each call station. These switching devices consist of

a two-part switch key and so many times two isolated from each other and among themselves Contacts that are available as extensions in the line dialer system. There are special loop lines between these contacts in the usual way placed in such a way that they only ever from one intercom to lead to the other specific place. The call is now made as usual, and the

ίο Conversations are initially carried out using the Line selector of the calling party and the line line of the called party using a common return in the known manner of the single line dialer systems guided. If it is now desired that a conversation between two bodies from a third party If the place is not to be overheard, it must be done in the prescribed manner Understanding the special two-part switching device with the calling and also at the called station to bring those contacts to which the to them Stations belonging loop line is connected, whereby the speech sets of the respective intercommunicating places are switched to the loop mentioned below complete shutdown of the other line lines and return line respectively. Line picker. So in this circuit it is not just the separate loop lines and associated ones special switching devices, but also the usual simple lines In addition to the line dialer in the familiar circuit of the single line line dialer systems required.

The BEZW with these examples listed. Circuits connected Disadvantages and disadvantages, which are mainly due to the fact that in the first example the electromagnetic indicators, in the second example the considerable increase the lines and switching devices make the system very expensive and complicated, should now be according to the present Invention avoided by a circuit, which enables the same mode of operation, like the circuit marked as the second example, but not in which one more is necessary, the line selector lines and the line selector of the single line systems to maintain. In addition, the present invention is different from that of the first example required electromagnetic indicators.

The circuit is illustrated in the accompanying drawing Fig. Ι, namely are three microphone units are assumed to be mutually connected to each other. The call stations are labeled I, II, III in the drawing. Since the invention is only to be explained with reference to the points I, II, only have parts of these points all relational signs received.

The line network consists of three loop lines abc, the common return line d and the common call battery line e. The connection of the latter two lines to the individual points is the usual.

Loop α is from point I to point II, loop b is from point I only to point III and loop c is from point II only to point III.

Each call station is equipped with switching devices fg / ?, respectively. ik h. ₂ resp. 1 mh ₃ equipped. The switching devices are operated by pressing a button u . A special mechanical device allows the button to be locked in the depressed position. Instead of buttons, the switching devices can also be operated using levers, plugs, etc.

The switching devices f'giklm are of the same design and consist of springs or contacts 1, 2, 3, 4, 5, 6. The switching devices It ₁ Ii ₂ h ₃ are also of the same design and consist of springs or contacts 7, 8, 9 .

One of the springs 1 and 4 of each pawl is attached to one, and the second to the other Line wire connected to the associated loop. The circuit of each digit is in explained below with reference to point I.

In the rest state, the springs 1 of each pawl rest on the spring 5. The springs 5 are connected to one another. The spring 5 of the pawl f is also connected to its own springs 6 and 2 with spring 6 and spring 2 of the pawl g and line 10 with the call button O ₁ and with the speaking device t _x and ringing device q U ₁ connected to it. The springs 4 and the lead wires connected to them are not in contact with the parts of their own apparatus at rest.

The springs 3 are conductively connected to one another and to the working contact 8 of the pawl H ₁ , but not to other parts. The line S ₁ connects the spring 7 of the pawl Zi ₁ with the changeover switch T ₁ .

Since the spring 7 is in the rest state on spring 9, to which the general return line d is connected, the line S ₁ and changeover switch T _{1 are connected} to the general return line through this.

One pole of the speaking and ringing apparatus is, as usual, led to the call button, which, as described above, is connected to the toggle pawls fg , while the other pole is connected to the toggle switch T ₁ , line S ₁ and toggle pawl Zz ₁ in the idle state of the latter a connection

with the general return line d . The other parts of each intercom station, some of which are not shown for the sake of clarity, are the usual ones and are also switched among themselves in a known manner.

If one of the pawls / gi k I m is now operated, the springs i, 2 are lifted off the springs 5, 6 and placed on the springs 3, 4. When one of the pawls H ₁ h ₂ h _& is moved, the spring 7 is lifted off the spring 9 and placed on the spring 8. The circuit achieved by the circuit of one or more pawls will be explained below in connection with the circuit description.

It is now assumed that station I wishes to speak to II. For this purpose, the pawl / can be switched by pressing its button u . When the call button O ₁ is pressed, the current of the wake-up battery ρ now flows through line e, button O ₁ , line 10, to spring 2 of the pawl g, spring 6, to spring 2 of the pawl / and then, since the spring 2 of the pawl / lifted from the spring 6 and switched to spring 4, to which the line 11 of the loop α is connected, into the line 11, to spring 1 of the latch i at point II and here to spring 5, spring 6, spring-2, Spring 6 of the pawl k, spring 2, line 12, call button O ₂ , in ringer q U ₂ , whereby the 'latter is excited. From the bell q U ₂ , the current flows through the normally closed contact 13 of the changeover switch r ₂ , into the line s. ₂ , to the spring 7 of the pawl h. ₂ , spring 9 into the common return line d and through this back to the other pole of the battery p.

As soon as the bell rings in the intercom II, you can do this without any further handling on the switching devices, d. H. that is, without the associated latch at position II is switched, the intercom can be operated, and after the same also in the Intercom station I has happened, the speech flow now takes the following course:

λ ^ οη one pole of the telephone t _{Y of} the microphone station I, which is thought to be schematically combined with the induction coil, microphone, etc., the speech current flows through the call button O ₁ , line 10, spring 2 of the pawl g, spring 6, spring 2 of the pawl / Spring 4, through line 11, spring 1 of the latch i, spring 5, spring 6, this latter via spring 2, spring 6 of the latch k, spring 2, line 12, call button O ₂ , in the remote receiver t. ₂ and from here through the switch r ₂ , which - as usual - is switched from the normally closed contact 13 to the normally open contact 14 when speaking, in line s. ₂ , spring 7 of the latch Λ ,, spring 9, common return line d, back to the call station I, here by spring 9 of the pawl Ji ₁ , spring 7, line S ₁ , by changeover switch T ₁ , which is also switched from contact 15 to contact 16 when speaking, again to the other pole of the telephone ^ ₁ .

In the called station, there was no operation of the line selector necessary.

If these two bodies now wish to have a conversation that a third party should not overhear, they communicate this wish to one another in the manner described above and then at point II the handle i and Ji ₂ and at point I the handle Ji ₁ through Press the associated buttons u to switch. The speech stream then takes the following path:

From one pole of the 'speaking apparatus ^ ₁ at point I, the current flows through button O ₁ , line 10, spring 2 of pawl g, spring 6, spring 2 of pawl /, spring 4, line 11, to point II, through here Spring 1 of the pawl i, which is now connected to the spring 3, in line 17, spring 8 of the pawl h. ₂ , which now rests on spring 7, line S ₂ , changeover switch r. ,, in contact 14, speaking device t, ₂ , through this to button O ₂ , line 12, spring 2 of the pawl k, spring 6, spring 2 of the pawl i, spring 4, spring 2, since the latter is now on spring 4, line 18, back to the call station I, here through spring 1 of the latch /, spring 3, which is now on spring 1, line 19, spring 8 of the latch H. ₁ , spring 7, which is now connected to spring 8, line J ₁ , changeover switch T ₁ and through contact 16 back to telephone t ₁ .

The loop α and the connected speech sets at points I and II are thus completely separated from the other sets and lines, so that eavesdropping is impossible. ' ■.

It can be seen from the foregoing and is readily apparent from the accompanying drawing it can be seen that the circuit forming the subject of the present invention is contrary to the previously known line selector circuits with double-line operation, a call at will through a line line and general return or provided by two associated line wires, without the usual lines of a line dialing system in addition to the loop lines for single line operation - as it is in the English circuit No. 5136 of 1900 is the case - would be required.

Instead of the double morse keys described above, other appropriate keys can also be used Find switching devices in a marked arrangement. Can also described circuit can be expanded for any number of microphone units. It is also that Possibility existed, the invention only

. to be used for individual positions of a line dialing system and the other extensions only set up for single line.

The presented invention can also be carried out with such switching devices, which is only the union of individual, not all parts of the above are described switching devices. The circuit made by their operation the apparatus of the calling and called party to the respective line wires used and also to each other is fundamental the same as that of the arrangement shown in Fig. ι.

For example, such a circuit arrangement of a speech station is shown schematically in FIG shown, the already -in Fig. 1 Parts shown and not belonging to the invention have the reference symbols of the point I (Fig. 1) have received.

The plug η has two conductive parts 20 and 21 that are insulated from each other. These two parts combine the springs 2 and 3 (Fig. 1) of each pawl of a call station, in that one part is in conductive connection _{with the button O 1 and the second} Part of the normally open contact 22 of the switch χ is performed. . The general return line d is connected to the normally closed contact 23 of the switch χ. The switch χ thus replaces the latch H ₁ . The pawls W ₁ n>, _{2 shown} in the drawing consist of three springs or contacts 24, 25, 26. The springs 24 and 25 actually serve the same purpose as the springs 1 and 4 in FIG. 1, since they are attached to one of the springs 24,25 one line, to the other spring the second line of the associated loop is connected. Instead of one of the springs 24, 25, 26, the pawl or socket body itself can be used. Two springs, designated in the drawing by 24, 26, each pawl lie against one another in the rest state. The springs 26 of each pawl are also connected to one another and to the normally closed contact 27 of the switch \ . By the switch \ entertain the springs 26 with the call button O ₁ and through this with the speech set ^ ₁ respectively. Bell device q U ₁ a connection. The springs 26 thus replace the springs 5 (FIG. 1) and the switch \ combines in itself or replaces the springs 6 shown in FIG. As soon as the plug η is inserted into one of the pawls W ₁ or ₂ , the springs 24 are lifted off the springs 26 and a connection such as that explained in FIG. 1 in connection with the circuit description is established. The intercom stations connected in this way now run through a line line and through the general return line d.

If, after mutual understanding in the aforementioned manner, a secret conversation is desired, the called party puts his plug η into the pawl to which the associated loop is connected. and both the callee and the caller switch off their switch 'x' from contact 23 to contact 22 and switch \ from contact 27. The speech current profile caused by this is the same as that explained with reference to FIG. 1 as a second example, in which the. Speech sets of the respective places speaking to one another are switched to the associated loop, with complete disconnection of the other lines and general return line d.

The switches χ and ^ can be combined by an isolated connecting piece ν - as shown in dotted lines in FIG. 2 - in order to switch the two over with one hand and at the same time.

The union of the springs or contacts of the pawls shown in Fig. 1 into others respectively the replacement of the same by other switching devices can be carried out in the most varied of ways Wise done and the arrangement shown in Fig. 2 serves as an example.

In view of the fact that it is often desirable or even a condition to be able to call a point that speaks to someone else, you can use Zi ₁ h. ₂ h ₃ (Fig. 1) arrange duplicates.

As known and from the first circuit description is readily apparent when using a line wire .und the general Return line for the conversation this call option insofar as the The party calling later can announce their request by intermittent speaking. But it is this for calls that are on the associated loop with complete shutdown of the other lines is carried by the intercoms, is not possible.

In order to provide a call signal in this case as well, as already mentioned, and in Fig. 3, which has received the relational symbols for position I (Fig. 1), it can be seen, instead of a simple Morse code key Zz ₁ h. ₂ h _n double beat ₄ used. The circuit described above is changed in such a way that one pole of the alarm clock is not connected to the call button O ₁ , but directly to spring 5. The other pole of the signaling device is led to the spring 28, which rests against the spring 29 at rest. Spring 29 is connected to contact 15 of changeover switch r _t . As already mentioned, the latter is connected to the general return line d by line S ₁ , spring 7 and spring 9.

If now the double morse key h _{i is pressed}

is, the connection between the springs 5 and one pole of the bell q U ₁ remains, while the other pole of the alarm clock q U ₁ by the spring 28 of the pawl / z ₄ , which is switched off after the actuation of spring 29 and on spring 30 is placed, is connected directly to the general return line d , since this line is connected to spring 30. The call from a third party can thus be made without the fear of current distribution and therefore eavesdropping, since the speech current flow remains the same as described above, ie the so-called. Here too, secret conversations are conducted on the associated loop, with the remaining lines being completely disconnected from the speech apparatus; the call current of a third station, however, flows via a line wire and a spring i, spring 5, alarm clock <£ ii _v spring 28, spring 30, directly through the general return line back to the calling station. The alarm clock is therefore excited.

The arrangement shown in FIG. 4 follows the same principle as the one last described and serves as an example that the _{Morse code key added to latch / z 4} can be replaced by a switch y while maintaining the arrangement shown in FIG.

The circuit is changed in that one pole of the alarm clock is connected directly to the spring 26, while the other pole is led through switch ^ and its break contact 31 to the break contact 15 of the changeover switch r ₁ . The changeover switch r is, as is known, through line S ₁ , switch χ and its normally closed contact 23 with the general return line d in connection. If the switch χ is moved, the connection between the springs 26 and one pole of the alarm clock q U ₁ remains, while the other pole of the alarm clock q U ₁ maintains a direct connection through the switch y and its normally open contact 37 with the general return line d , since this line is connected to contact 37 and the switch χ was switched from contact 31 to contact 37 when it was operated.

The switch y can also be operated with the switches χ and \ at the same time if the former is connected to the extension of the insulated connector ν .

Claims (4)

Patent Claims: i. Circuit for telephone systems with line dialer operation, in which a or several call stations with one or more extensions through loop lines and a general return line, characterized in that the connection is connected by means of the Line network built-in switch can be established in such a way that the conversation between two bodies either on one line a loop intended only for these places and the general one Return line is led or on both lines of the same loop with disconnection of the rest of the network, to Purpose to avoid both optical signals and the usual single lines. 2. An embodiment of the circuit according to claim 1, characterized in that by operating one of the double-pole line selector keys arranged at each such point (for example fg or ik or Im [Fig. 1] or W ₁ w. ₂ [Fig. 2]) ) only at the calling point the call signal via one of the associated loops (for example a or b or c) forming two wires and general return line (d) given respectively. the call is conducted on the lines mentioned, while when operating one of the double-pole line selector keys (e.g. fg or ik or Im [Fig. 1] or W ₁ ηλ> through η [Fig. 2]) and a the switching device (example of \ veise It ₁ BEZW. A ₂ BEZW. h ₃ [Fig. 1] or χ% [Fig. 2]) of both the calling and the called site of .Sprechstrom only on the associated loop forming lines departures respectively can flow back by completely disconnecting the remaining lines and speech sets from the loop and speech sets used in each case. 3. A circuit according to claim 1, characterized in that the two lines (e.g. 18, il) of each loop with the associated microphone units on the one hand to a free or working contact (for example 4 [Fig. 1] or 25 [Fig. 2]), on the other hand to a changeover contact (for example ι [Fig. 1] resp. 24 (Fig. 2]) are performed, the latter with contacts (for example 5 [Fig. 1] or 26 [Fig. 2]) is connected to each other with the signal respectively. Speech sets at one point Maintain conductive connection for the purpose as described in claim 1. 4. A circuit according to claim 1, 2 and 3, characterized in that instead of the simple switch claimed with reference to FIG. 1 (for example Ji ₁ Zj ₂ Zi ₃ ) double (for example A ₄ [Fig. 3]) are arranged respectively. that for the switch claimed with reference to FIG. 2 (for example χ ^) a switch (for example y [Fig. 4]) is added, one pole of the signaling apparatus being connected to one line of each associated loop, while the other pole is connected to the switch (for example T ₁ r ₂ r ₃ ) by the added switching device in the idle state and by means of this to the general return line (for example d) , while in the working state of the switching device, the latter pole of the alarm clock receives a connection directly to the general return line (d) for the purpose of being able to call the secret-speaking bodies through the associated loop from a third party to be able to. 1 sheet of drawings,