DD295293A5 - TELEPHONE APPARATUS, SUITABLE FOR CONNECTION TO DIFFERENT REMOTE CONTROL LINES - Google Patents

Abstract

The invention relates to a telephone set capable of communicating with each of a plurality of trunk lines. The user has the advantage of not having to choose a free line every time. To this end, the apparatus includes a line-voltage detector which issues a busy signal when the user picks up the handset to make a call when the line to which the apparatus is connected is called by a call to another telephone on the same line is occupied. A control circuit of the apparatus uses this busy signal to connect the apparatus to another line. Fig. 1

Description

The invention relates to a telephone set that is able to be connected to a line of formold line, each of which has the capability of being free or busy, and each of which is capable of transmitting a call sign. Dor Telefonapparat contains eino oloktroakustischo E nhoit, which has a microphone and a handset sowio switching elements, dio on each dor genannton call sign ansprochon to wahlweiso the gonannto elektroakustisch!) Unit with dor line to bind, woli ho diosos call signal transmits.

Such apparatuses are known allgomoin. So biotet z. For example, the Swiss telephone company offers your customers an "accessory for two lines, title BZ 85,22" for mimini, which can be connected to two emergency call lines and to a conventional telephone set in order to form with it an apparatus which fulfills the definition, which was given in the preceding, corresponds.

When a call signal on one of the two lines connected to the dome apparatus is ompfangon, the accessory considered above automatically establishes the connection between that line and the telephone set so that the user of the apparatus picks up the handset to answer the call, is currently connected to the caller, without having to do any further manipulation.

If one of the two lines has been set as operation line and the accessory set out above has been set accordingly, the handset will always be connected to this priority line when a user picks up or makes a call.

Otherwise, if or oinon wants to make a call, the user must select one of the two lines by pressing a push-button switch.

It occurs more and more that two or more Telofonapparto are connected in parallel on the same customer line, these devices z. B. in different rooms of the same apartment or dos the same house.

In such a case, there is a chance that the user of an apparatus as described above is connected to his handset to a line which is already busy by another call when picking up his handset to make a call make. This user must then manually select another line to be able to make his call.

The invention has for its object to be connected to a telephone set that is gooignet with a plurality of telecommunication lines, each of which has the ability to be free or busy, and each of which is capable of transmitting a call sign, whose handset is automatically connected to a free line, if one is available when the user picks it up to make a call.

According to the invention the object is achieved by a telephone set adapted to be connected to a plurality of telecommunication lines, each of which may have a free or occupied condition and capable of transmitting a call signal containing an electroacoustic unit comprising a microphone and a handset, and switching means responsive to each of said paging signals for selectively interfacing said electroacoustical unit with the telecommunications line carrying said paging signal, further comprising means for generating a signal indicative of the use of said signals indicated electroacoustic unit and means for generating a busy signal responsive to the line which is connected to said electroacoustic) unit is occupied, and said switching means are further able to the use of said signal to React which use and to said busy signal to connect said electro-acoustic unit to another of said telecommunications lines.

The invention will be explained in more detail with reference to an embodiment. In the accompanying drawing show

Fig. 1; a schematic embodiment of the telephone apparatus of the invention; Fig. 2 is a block diagram of a control circuit which may be used in the apparatus according to Fig. 1; 3 shows the block diagram of a line voltage defect, which in the control circuit according to the Fig.2

Can be used; Fig. 4: schematically a second embodiment of the telephone set.

The telephone set 1 is shown as a circuit diagram in FIG. It contains four input lines 1 a; 1 b; 1 c; 1 d. The input lines 1 a; 1 b are provided so that they with two wires A1; A2 are connected, which together one

Formation A, which is at your oiuloron end with the old telecom office. The entrance Lungungon 1 c, 1 cl dos Tolofonapparatos 1 are with two Ortthten B1; B 2 before Bunclon, wolcho zusammon olno zwoito Forlsprechloltung B blldon, which at the end is at its end preceded by an old telephone exchange. The telephone set 1, moreover, as it is known, has a square (not shown) which is connected by means of an external connection with an external handset 2, comprising a receiver 3 and a microphone 4. If the handset 2 is not used, it can be decoupled on the acceptor on Dom Qrundolemont, which is part of the same, as is conventionally customary, with the handset 2 with the output of Sproc'ikrelso 5 unbound, with dosson HiKo Signalo who are permitted to charge the auditorium 3, may have been gotronnt by clonon, wolcho through the microphone 4 orzougt wordon.

The Tolforon apparatus 1 has a bistable relay 6, which is provided by Spulon Ga; Has 6b, comprises first of Donon Oino Anschlußloitung, n. ^1, "the positive pole is connected olnor Enorglovorsorgung is wolcho beschriobon hereinafter and Oino zwoito lead, wolcho with oinom Steuerstromkrols vo bunclon which is boschriobon ebonfalls hereinafter.

The relay 6 woist continues to four gleichpoligo contacts 6.1; 6.2; 6.3; 6.4 on, are mechanically connected with each other in such a way that the contacto 6.1; 6.2 are always in the same closed or opened state and contacts 6.3; 6.4 Always in the ontgogongosotzte switching state to don contacts 6.1; 6.2.

The relay 6 is also constructed in such a way that dlo Kontakto 6.1; 6.2; 6.3; 6.4 sirh i ;. 1, when a current pulse is supplied to its coil 6a and in its opposite switching state when the coil 6b is supplied with a current pulse. These two switching states have been arbitrarily referred to as the orsto and the second switching state of the relays 6.

The first terminals of the contacts 6.1; 6.2 are correspondingly with the connection terminal 1 a; 1 b dos Tolefonapparates 1 connected and with the terminals 7 a; 7b of a call circuit 7.

This call circuit 7 should not be written here in detail, because or allgomoin is known. Suffice it to be gosagt that in this example the circuit dorart is arranged that its output 7c generates a logic signal which is high in response to a call signal on dor line A and which goes to oinon low level in the absence of this call signal. This state of high and low levels will be defined below.

The ringing circuit 7, moreover, conventionally includes a bell, a buzzer, or any similar device capable of producing a distinctive sound or sound. This generated noise is in response to the above-mentioned call signal.

In the same way, the corresponding contacts are 6.3; 6.4 with the leads 1 c; 1 d of the telephone set 1 verbundon and with the terminals 8a; 8b of another call circuit 8.

This call circuit 8 is constructed in the same way as the call circuit 7 considered above. Like the latter, it has an output 8c which generates a logic signal which is high in response to a call signal on the line 8 and which, in the absence of this call signal, is high low level goes. Like ringing circuit 7, ringing circuit 8 includes a bell, buzzer or other similar device capable of generating a distinctive sound or sound in response to ringing signals on line 8 and, if desired, a ringing tone Signal lamp which lights up in response to these ringing signals. The second terminals of the contacts 6.1; 6.3 are connected in common with the first terminal of a contact 9.1, which is actuated in the present example by a pressure pin, which is arranged in the support part of the handset 2 such that the contact 9.1 is opened when the handset is not in use and on this support part rests and which is closed when the handset 2 is released from the receiving part, with the intention to use it.

The second terminal of the contact 9.1 is connected to the emitter of a bipolar pnp transistor 'IO whose collector is connected to a first terminal 5a of the speech circuit 5 and to a first terminal 11 a of a voltage-detector circuit 11, which in the following in individual is described.

The second terminals of the contacts 6.2; 6.4 are connected together with a second terminal G b of the speech circuit 5 and a zweiton terminal 11 b of the voltage-detector circuit 11.

The telephone set 1 according to Fig. 1 further comprises a selection pulse generating circuit 12 which is e.g. may include a keyboard having 10 keys numbered from 0 to 9 forming an electronic circuit 12 and arranged such that this output 12a normally has a low level and outputs one of the keys, a given number, in response to daily actuation of pulses during which the level is high, the number of pulses depending on the digit of the operated key.

The telephone apparatus according to FIG. 1 also has a control circuit 13. A corresponding example will be described below. The control circuit 13 has inputs 13a; 13d, which correspond respectively to the outputs 7c; 8c; 11c; 12c of the circuits 8; 7; 11; 12 are connected and an input 13 e, which is connected to a first terminal of a contact 9.2, the second terminal is connected to a positive pole of the energy supply just mentioned. As well as the contact 9.1, to which it is mechanically connected, the contact 9.2 is opened when the handset 2 rests on the receiving part of the telephone set 1, and it is closed when this handset 2 is used.

The control circuit 13 further has outputs 13f; 13g; 13h, which correspond to the second terminals of the relay coils 6a; 6 b and connected to the base of the transistor 10.

The electrical energy needed to operate the various circuits of the telephone set 1 is transmitted via both lines A; B via the power source 14, which z. B. may be a simple voltage stabilizer fed. The inputs 14a; 14bdieser power source 14 are corresponding to the second terminals of the contacts 6.1; 6.3 and the second terminals of the contacts 6.2; 6.4 connected so that they always with one of the lines A; B are connected, regardless of the switching state of the relay. 6

The outputs 14c; 14d of the power source 14, which respectively form its negative terminal, denoted by the symbol (-) and its positive terminal, denoted by the symbol (+), are connected to the corresponding circuits of the telephone set 1, the connections not being shown. In addition, the

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Terminal 14c is connected to the output terminal 14b and its potential is the reference potential for the entire tuple apparatus 1. In the preceding gonangonon, the nthtalrlgon and the hologonly loglchon levels, discussed below, refer to the potential of the negatlvan terminal 14c and the potential gate the posltlvon terminal 14 d of the power source 14th

Fig. 1 also shows that there are two telephones connected to the world, the olno to the porn voice-link A and the other to the remote telephony B. Dloso woitoron Telophonapparato, designated 15; 16, can not be described by jodom guy soin and here.

FIG. 2 shows the block image oinor Ausführungsvariantn the Stouorstromkrelses 13, corresponding to FIG. 1, the. Diosor control circuit includes AND Gattor 21; 22; 23; 24; 25; 26, OR Gattor 27; 28; 29, inverter 30; 31; 32; 33; 34, RS flip-flops 36; 37; 38; monostable circuits 39; 40, a delay killer 41, two! Inverter 42; 43, oonon bipolar npn transistor 44 and two resistors 45; 46th

All these elements are connected to each other and to the entrances and exits of the Stouorstromkroises 13, dio with the same reference numerals, wio are in Fig. 1 bezoichnot, in the manner as it dargosiellt In dor Fig. 2. These precedents are not described in detail.

Fig. 3 shows a block diagram of the voltage detector Schaitkrelsos according to the FIg. 1.

In this Ausführunqsvarlante the circuit contains zwol resistors 51; 52, which between the clumps 11 β; 11 b are arranged in series. The connection point dor resistors 51; 52 is connected to the base of a bipolar NPN transistor 53, whose emitter is also connected to the terminal 11 b and whose collector is connected to the output 11 c and via a resistor 54, with the positive terminal of the power supply 14th

The resistors 51; 54 are selected so that the transistor 53 is turned on and thus is low in output level when the voltage between the terminals 11 a; 11 b is equal to the voltage between the two wires of a telephone line when it is free, i. H. z, B, 48 V and such that the pegol of the output 11c is high when the voltage between the pits 11a; Figure 11b shows the tension between two wires of a telepono-cord when Istztoro is in use, e.g. 10V.

To the operation of the telephone set 1, according to FIG. 1, to project, as it is boschrieben in the following in connection with the operation of the control circuit 1 e, according to the Fig.2, it should be noted that in a conventional manner, the Q or the direct output of each flip-flop 36; 38 has a low or a high level, depending on whether a logic signal with hohom level is set at its R input or at its S input. The Q or dot inverted output of each flip-flop 36; 38 obviously always has the opposite switching state to its Q.

It should be further noted that each of the monostable circuits 39; 40 at its output in response to each transition of its input from a low level to a high level, gives a pulse of given duration, i.e. its output is high for a given duration and then returns to the low level.

As will be apparent from the description below, this biased duration of the period of time that the current pulse applied to the coil 6a or coil 6b of the relay 6 must be to switch the relay to its first or second switching state. It is also to be noted that again in a conventional manner the output of the delay circuit 41 normally has the same logic switching state as its input, but that the corresponding change of its output takes place only after a given time delay when its input is at a high level goes to a low level.

It is assumed at the beginning that the telephone set 1 is not used, i. H. that the handset 2 rests on its support and the contacts 9.1; 9.2 are open and that the other phones 15; 16 also not be used.

Under these conditions, the level of the input 13e of the circuit 13 remains low, because it is connected via the resistor 45 to the negative terminal of the power supply 14.

Likewise, under the same conditions, the other inputs 13a; 13d of the circuit 13 to a low level. It is easy to see that the outputs 13 f; 13g of this circuit have a high level. For this reason, no current flows in the coils 6u; 6b of the relay 6. In addition, the transistor 44 is blocked by the signal which is placed at its base by the output of the gate 26 and which has a low level. The transistor 10 is also blocked for this reason.

If a call signal is transmitted under these conditions, eg. B. via the telecommunications line A, the circuit 7 outputs at its output 7 c and thus at the input 13 a of the circuit 13 from a high signal level and causes a ringing or any other characteristic noise, which indicates the subscriber to the telephone set 1 that there is an incoming call.

When the subscriber picks up the handset 2 to answer that call, the contacts 9.1 close; 9.2. The input 13e of the circuit 13 is now connected to the positive terminal of the power supply 14 via the contact 9.2 and for this reason assumes a high level. It is easy to see that the output of gate 21 also goes high, as does the output of gate 28. The output of the monostable circuit 39 therefore provides a pulse during which the output 13f of the circuit 13 is low, with the result that a current pulse flows into the coil 6g of the relay. This current pulse switches the relay 6 in its first switching position, d. H. in the position shown in Fig. 1, provided, of course, that the relay is not already in this position, in which case this current pulse has no effect.

The pulse which is output at the output of the monostable circuit 39 also causes the Q output of the flip-flop 38 to go high, provided that this output is not already high.

In addition, the Q output of the flip-flop 36 assumes a low level when the output of the gate 21 assumes a high level because the subscriber picks up the handset 2 from its support member, which causes via the gate 27

Finally, the transistor 44 and transistor 10 are also passed through, which has gowobonon priority, which is due to the characteristics of the forward bias 41, when the torch picks up the handset 2 and the input 136 of the circuit 13 adopts the high pogol. The biasing voltage can be about 600 milliseconds.

From Dom Augonblick, in which transistor 10 is passed through, the speech circuit 6, and consequently also the handset 2 with the front-end connection A, becomes vorbundon, and the toilnohmor on the tol- bling apparatus can thus boglnnon to talk to the caller.

The communication line A is therefore now occupied and the output 11c of the circuit, which had a low pogol vorhor before, now takes olnon high Pogol on; as does the input 13c of the circuit 13 and the gate 21; 22 are blocked via the inverter 31. For this reason, in the event that the input 13b of the circuit 13 becomes high in response to another incoming call to the remote terminal B, no further switching of the relay 6 can be caused, which would have the effect of interrupting the connection above between aor Fornsprechleitung A and the speech circuit 5 was made.

The increase in the level at the input 13o has no effect on the gate 23, which is already blocked by the signal with another level, which comes it at the Q output of the flip-flop 36.

When the subscriber on the telephone set 1 hangs up the handset 2 at the end of the conversation, the contact 9.2 opens wiodur and the input 13o of the circuit 13 again assumes a low pegol.

This decrease of the F'egels at the input 13e via the inverter 32 with the result that the Q output of the flip-flop 36 again assumes a high level and via the delay circuit 41 and the gate 26, the transistor 44 and consequently the transistor 10 are disabled. The telecommunication line A is at the same time free again for this reason, and the output 11 c of the circuit 11 again assumes a low level.

It can be seen that the circuit 13 and the telephone set 1 are at the same time again in the same switching state as at the time when the incoming call was received via the telecommunication line, possibly with the sole exception that the Fl ^ Ίορ 38 and the relay 6 both remain in the switching state that they had assumed when the subscriber has picked up the handset 2.

If, under these conditions, a new call signal is transmitted to the telephone set 1, but this time over the trunk line B, it can be seen at the same time that it is the output of the monostable circuit 40 which gives a pulse when the subscriber picks up the handset 2, to answer the call.

During this pulse, the output 13 g of the circuit 13 has a lower level, with the result that a current pulse in the coil 6 b of the relay 6 flows. The latter therefore assumes its second switching state. In addition, the pulse, which at the output of the monostable. Circuit 40 is generated, with the result that the flip-flop 38 switches to the state in which its Q output has a lower level.

Finally, as in the case described above, in which the incoming call signal is transmitted via the telecommunications line A, the non-Q output of the flip-flop 36 goes to a lower level when the user picks up the handset 2 and becomes after a given time the transistors 44 and 10 turned on.

The speech circuit 5 and consequently also the handset 2 are therefore connected to the telecommunication line B, and the user of the telephone set 1 can talk to the caller. As in the previous case, the output 11c of the circuit 11 goes high in response to the busy state of the telecommunication line to which the telephone set 1 is connected.

Further, as in the previous example, when the subscriber places the handset 2 on his seat at the end of the conversation, the circuit 13 and the telephone set 1 are both in the state they were in before the conversation started, with the sole exception , the flip-flop 38 and the relay 6, which remain in the switching state that they had taken when the participant has received the handset 2.

If both trunk lines A; B simultaneously transmit a call signal, the two inputs have 13a; 13b of the circuit 13 is a high level. But the low level then present at the output of the inverter disables the gate 22. For this reason, when the subscriber of the telephone set 1 picks up the handset 2, the circuit 13 operates in the same way as described above, in the event that only the telecommunication line A transmits a call.

If a call signal is still waiting on the communication line B or if the subscriber on the telephone set 1 hangs up the handset 2 on the receiving element at the end of the conversation thus obtained, the circuit 13 operates in the same way as described in US Pat has been described above, in the event that only a single call on the trunk line B has been transmitted.

It has been seen from the foregoing that the Q output of flip-flop 38 goes high and, upon completion of the communication, maintains this high level when the subscriber on telephone set 1 picks up the handset to answer an incoming call on trunk A answer. In a similar manner, the Q output of the flip-flop 38 goes low when the subscriber on the telephone answers an incoming call on the trunk B and maintains this condition until the end of the call. It will be seen below that the Q output of the flip-flop 38 also goes high, or a low one, depending on whether the call is out in a manner to be described later, on the trunk A or on the trunk B is performed when the subscriber on the telephone set 1 makes an outgoing call and that the logical state of this output is not changed at the end of the outgoing call.

For this reason, between the connections, the switching state of the Q output of the flip-flop 38 always indicates with which telecommunication line A; B the telephone set 1 was connected during the last connection.

This technique is used to connect the telephone set 1 to a free line, if any, when the subscriber on the telephone set 1 picks up the handset 2 to make an outgoing call.

It should be assumed at the beginning that none of the telephone sets 15; 16 with the telecommunication lines A and Bverbundon is and is used and that, of course, no call signal is present on one of the two lines. It should also be assumed that the relay 6 is in its first switching state.

Under these conditions, when the participant in the telephone set 1 picks up the handset 2 to make a call, the closing of the contact 9.1 results in the relatively high voltage between the two loudspeakers of the communication line A, which between the terminals m.ι e < 11a; 11b dos circuit 11 is applied. The output of pin 11c of the circuit 11 and the input of the ijouo circuit, for no reason, are low, and spurron through the gate 23. Because the outputs 7c; 8c the calling code 7; 8 and thus the inputs 13a; 13b of the ebonso oinon circuit have low levels, the gates 21; 22 also blocked.

It is easy to see that in this case koiner dor monostable circuits 39; 40 generate a pulse and that the switching state dos relay 6 remains unchanged. The transistors! 44; However, if the output of the delay circuit 41 assumes a high level, this is considered to be high in the above examples. The speech circuit 5 and the handset 2 have now been merged with the foreword-clipping Averbunden, wolcho from oinemfrei into an occupied state). The output 11c of the switching circuit 11 assumes a level from this gronnlo oonon hohon, but this change is not a consequence if the gate 23 is blocked by the signal with low pogol, which is canceled by the output of the inverter 33 in response to the signal Hohom Pegol signal at the output of the Vorzögorungs-Schaltkroises 41, is disabled.

The subscriber on the telephone set 1 can therefore choose to dial the number or call or dial by pressing the dialing device 12 after having heard the usual audio signal from the telecommunications office, indicating that the telecommunications office is ready to pick up the desired number.

As already mentioned, the output 12a of the selector 12 generates a given number of pulses each time one of the selector buttons is operated.

Each of these pulses via the inverter 34 and the gate 26, that the transistors 44; 10 are locked. The interruptions of the circuits caused by the successive spurs of the transistor 10 are displayed in a well-known manner by the telecommunications office to which the telecommunications line A is connected and allows the telecommunications office to connect the telephone set 1 to the central subscriber which should be called. If the user at the end of the conversation places his / her handset 2 on its receiving device, the telephone set 1 and the circuit 13 are in the same state they were in before the subscriber picked up the handset. It is easy to see that the relay 6 is in its second switching state, in which its contacts 6.1; 6.2 are open and its contacts 6.3; 6.4 are closed.

When the subscriber on the telephone set 1 picks up the handset 2 to make a call, the operation of the circuit 13 is exactly the same as in the case just described, except that in this case the connection is made via the trunk line B. ,

When the subscriber on the telephone set picks up the handset 2 with the aim of making a call and the relay is in its first switching state, but the telecommunications line A is already busy by a connection to the telephone set 15, the closing of the contact 9.1, that the voltage which is present between the conductors of the telecommunication line A, to the terminals 11a; 11b of the circuit 11 is applied. Since the telecommunications line A is busy, this voltage is relatively low and the output 11 c of the circuit 11 and the input 13 c of the circuit 13 therefore assume a high level, as does the output of the gate 23.

This output of gate 23 maintains this high level only for a very short time, because its high level state causes the Q output of flip-flop 37 to go low, which in turn results in the output of Gatters 23 assumes a low level.

This output 23 therefore outputs a pulse, which via the gates 29; 25 is transmitted to the input of the monostable circuit 40. This happens because at this moment the Q output of the flip-flop 38 has a high level, due to the fact that the relay 6 is in its first switching state. The monostable circuit therefore generates a pulse which first tries to switch the relay 6 to its second switching state in which its contacts 6.1; 6.2 are open and in which its contacts 6.3; 6.4 are closed and which second causes the Q output of the flip-flop 38 to assume a low pegol. When the transistors 44; 10, in response to the output of the delay circuit 41 assuming a high level, the talk circuit 5 is connected to the telecommunication line B. When the latter becomes free, the subscriber on the telephone set 1 can then use the circuit 12 to dial the number of the subscriber he wishes to call after having received the usual audio signal from the telecommunications office. If the trunk line B is busy by a connection to the telephone set 16, the subscriber on the telephone set 1 can, if he so wishes, turn on one of the calls and request that the latter be disconnected and thus the line be cleared.

If he does not want to make use of this possibility to speak for himself, the subscriber on the telephone set 1 only needs to put the handset 2 back on its receiving element when he determines that the line to which he is connected is already busy.

In each FaM, the state of the telephone set 1 remains in the one it has when the subscriber places the handset 2 on its receiving element.

It is easy to see that the circuit 13 operates in a similar manner, as described above, when the subscriber on the telephone set 1 picks up the handset 2, with the aim of making a call and the relay 6 is in its second switching state , the trunk line B but already occupied by a connection with dom telephone 16. In this case, however, the pulse, which is output from the output of the gate 23, via the gates 24; 28 to the input of the monostable circuit 39, because the Q output of the flip-flop 38 has a high level. The pulse, which is then output from the monostable circuit 39, causes the relay 6 is switched to its first switching state and therefore the speech circuit 5 is connected to the telecommunication line A, when the transistors 44; 10 are controlled.

As in the previous case, the subscriber on the telephone set 1 can then dial the number of the subscriber he wishes to call. If the trunk line A is free and if the trunk line B is busy by connecting to the telephone set 15, he can engage in the conversation and request that the line be cleared or he

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The handset 2 can be put on the recording tool. Of course, the control circuit 13 can be arranged such that the translator IO is not passed through and the handset 2 is not connected to telephone lines A or B for diosomic reasons, in which Jio boidon t ^; angermoltololtungone A; B are connected by connections to the Tolofonapparaton 15 or 16, the dos waits, if the output 11 c of the voltage-anzoigo Schaltroroosos 11 wiodor elnon high bird takes, if the relay 6 solnon switching state iiiidort. In such case, which has not been illustrated, the circuit 13 may have been so affected that an audible and / or visual signal may be generated to warn the caretaker at the tollophone 1 that or koinon can make a call because both remote console A is sounding; B are occupied.

In the Ausführungsvarianto dor Tolofoiiappato according to the invention, which is shown in Figure 4, the telephone apparatus, wolchdr provided with num 101, is most of the elements of the telephone apparatus shown in dor Fig. 1. These elements are provided in the two figures with the gloichon reference numeral and will not be described again here.

Like the telephone set 1 shown in Fig. 1, the telephone set 101 includes terminals 101a; 101b, which are connected to a first telecommunication line A, to which another Tolefonapnarat 15 is connected and two terminals 101 c; 101 d, which are connected to the first telecommunication line B, which is also connected to another telephone set 16.

The Dor telephone has a second handset 102 which includes a handset 103 and a microphone 104 which are verbundon in a conventional manner with a talkback croissant 105.

In the same way as the telephone set 1, the telephone set 101 includes a bistable relay, similar to the reference numeral 106, which has two coils 106a; 106b, one of which is a terminal to the positive terminal of the power supply 14vorbundon. The relay 106 includes four switch contacts 106.1; 106.2; 106.3; 106.4, whose common terminals correspond to the inputs 101a; 101b; 101c; 102d of the telephone set 101 are connected.

The non-common terminals of the contacts 106.1; 106.4 are connected to each other and to the other elements of the telephone apparatus, as shown in FIG. From Figure 4 it can be seen that the telecommunication line A is connected via the contact 9.1 and the transistor 10 to the speech circuit 5, when the relay 106 is in its first switching state, as shown. It can also be seen that in the same switching state of the relay 106, the telecommunication line B is connected via a contact 109.1 and a transistor 110 to the speech circuit.

The contact 109.1 is similar to the contact 9.1, i.e., it is opened when the handset 102 is placed on its receiving element and closed when the handset 102 is detached from the receiving element to be used.

Similarly, the transistor 110 is similar to the transistor 10, i. it is also a pnp transistor and is also turned on under the circumstances described below when connecting to the handset 102.

4 also shows that it is the telecommunications line A, which is connected to the circuit 105 via the contact 109.1 and the transistor 110 and that it is the telecommunications line B, which communicates with the speech circuit 5 via the contact 9.1 and the transistor 10th is connected when the relay is in its second switching state.

The telephone apparatus 101 according to FIG. 4 furthermore has a second voltage-detector circuit 111. The terminals 111 a; 111b of the circuit 111 are respectively connected to the two terminals of the contact 109.1 and the first non-common terminal of the contact 106.4.

The telephone set 101 further includes a control circuit 113, which inputs 113 a; 113b; 113c; 113d, 113e, which are respectively connected, like the inputs 113a; 113b of the circuit 13 in FIG. 1, namely with the output 7c; 8c; 11c; 12a of the call circuits 7; 8 the voltage detector 11 and the circuit 12 for generating the dial pulses and the second terminal of the contact 9.2.

The control circuit 113 also has two outputs 113f; 113g connected to the second terminals of the coils 106; 106 b are connected and an output 113 h, which is connected to the base of the transistor 10.

The control circuit 113 also includes two inputs 113c; 113j which are connected to the output 111c of the voltage detector circuit 111 and a terminal of the contact 109.2, the contact 109.2 being mechanically connected to the contact 109.1 such that it is opened or closed at the same time as the latter ,

The other terminal of the contact 109.2 is connected to the positive terminal of the power supply 14.

Finally, the control circuit 113 has an output 119 h, which is connected to the base of the transistor 11.

The configuration of the control circuit 113 will not be described in detail because it can be easily deduced from the following description of the operation of the telephone set 101.

To begin with, assume that the handsets 2; 102 are both stored on their respective recording elements.

Wonn via the telecommunications line A a call signal arrives and a participant picks up the handset 2 to answer this call, the circuit 113 responds to the height of the level, which he then at its terminals 113 a; 113e receives by giving a current pulse to the coil 106a of the relay 106, which therefore assumes its first switching state, unless it is of course not yet in this switching state.

In addition, the circuit 113 allows the transistor 10 a short moment the closing of the contact 9.2 in the cut-through state. For this reason, the handset is now connected via the speech circuit with the telecommunication line A.

When the subscriber picks up the handset 102 to answer a call signal on the trunk B, the circuit 113 also delivers a current pulse to the coil 106a of the relay 106b to respond to the high level it receives at its inputs 113b; 113j, and a moment after the closing of the contact 109.2, the transistor 110 is switched to its on state. The relay 106 is therefore also switched to its first switching state, if it is not already in this switching state and the handset 102 is connected via the speech circuit 105 to the telecommunication line B.

In the same manner, the circuit 113 roams to the high level, or to the selenium inputs 113a; 113] ompfängt by giving a current pulse to the coil 106b of RoIoIs 106, so that the lotztore In solnon second switching state is transferred, if it is not in dlosem switching state boflndot when the subscriber receives the handset 2 to a call signal on Fernmoldeltungung B to answer or the handset 102 receives to answer oln call signal Dor telecommunications line A.

In addition, the circuit 113 controls the transistor 10, in the orston case, or controls the transistor 110 in the 2-way case, thereby connecting the handset 2 to the telecommunication line B or connecting the handset to the telecommunication line A. When the subscriber to the tollophone 101 wishes to bonutzon this to make an elnon call, the following various situations olntreton:

The participant picks up the handset 2 while

- The communication line A is free Is and the relay 106 is in solnom first switching state, or

- The Fornmoldoloitung B is free and the relay 106 was in its zwoiten switching state, or

- The telecommunication lines A and B are both free.

In this case, the output takes 11 c of the voltage-Dotektors-Schaltkroises 11 in response to the relatively high voltage which is applied to the terminals 11 a; 11 b of the circuit 11 is applied, a low level, whereby the closing of the contact 9,1 takes place, no matter which switching state of the relay 106 has. For this reason, the circuit 113 does not supply a current pulse to the coils 106a; 106b of the relay 106, which therefore does not change its switching state. However, a short instant after the contact 9.2 closes, the circuit 113 drives the transistor 10, thereby connecting the handset 2 to the telecommunications line A, when the retay 106 is in its first switching state or with the front panel B, when the speed is low 106 is in its zweiton switching state. In addition, the circuit 113 indirectly inhibits its input 113d with its output 113h so that the transistor is again turned off in response to each of the pulses generated by the select pulse generator 12 when the subscriber actuates its keys, to dial the number he wants to call.

2. The subscriber picks up the handset 102 while

- The telecommunication line A is free and the relay 106 is in its second switching state, or

- The telecommunication line B is free and the relay 106 is in its first switching state, or

- The telecommunication lines A and B are both free.

In this case, it is the output 111c of the voltage detector circuit 111 which in response to the relatively high voltage applied to its terminals 11a; 11 b is applied, assumes a low level, thereby closing the contact 109.2, whatever the switching state of the relay 106 is. In this case too, the circuit 113 does not give a pulse to the coils 106a; 106b of the relay 106, but a short moment after the closing of the contact 109.2, the circuit 113 controls the transistor 110, whereby the handset 102 is connected to the telecommunications line B when the relay 106 is in its first switching state or to the telecommunications line A, when the relay 106 is in its second switching state. In addition, the circuit 113 indirectly connects its input 113d to its output 113k, so that the transistor 110 is disabled in response to each pulse output from the output 12a of the circuit 12 when the subscriber dials the number to be called.

3. The subscriber on the telephone set 102 receives the handset 2, while the relay 106 is in its first switching state and the telecommunication line A is already occupied by a connection to the telephone set 15. In this case, the output 11 c of the voltage detector circuit 11 and consequently the input 113 c of the circuit 113 in response to the relatively low voltage level, which and the terminals 11 a; 11 b of the circuit 11 is applied when closing the contact 9.1, a hohon level.

If at the moment when the input 113c of the circuit 113 goes high, the input 113j of the circuit 113 is low because the handset 102 is not in use, the circuit 113 applies a current pulse to the coil 106b of the relay 106 which, for this reason, assumes its second switching state. As in the case 1 described above, the circuit 113 controls the transistor 10 a short moment after the closing of the contact 9.2 and indirectly connects its input 113d with its output 113 h. The handset is connected for this reason via the speech circuit 5 with dor trunk line B.

If line B is free, the subscriber can then dial the number he wishes to call. However, if the trunk line B is already busy by a call to the telephone set 16, the subscriber on the telephone set 101 can turn on that call and request that the telephone line be cleared or he can put the handset 2 back on his seat.

4. The telephone subscriber picks up the handset 102 while the relay 106 is in its first switching state and the telecommunications line B is already connected to the telephone set 16 by a call.

In this case, the output 111c of the circuit 111 and thus the input 113j of the circuit 113 increases in response to the relatively low voltage applied to the terminals 111a; 111 b of the circuit 111 is applied, when the contact 109.1 is closed, a high level.

Since at the moment in which the input 113e of the circuit 113 from a current pulse to the coil 106b of the relay 106, which therefore assumes its second switching state.

As described in the previous case 2, the circuit 113, a short time after the contact 109.2 is closed, also turns on the transistor 110 and indirectly connects its input 113d to its output 113k. The handset 102 is for this reason connected via the speech circuit 105 to the telecommunication line 105. If the telecommunication line A is free, the subscriber can therefore dial the number which he wishes to call. However, if line A is already busy by a call to the telephone set 12, the subscriber to the telephone set 101 can turn on that call and request that the dk trunk be cleared or he can return the handset to his receiver.

At the moment in which the entrance 1131 of the circuit accepts 113 oonon high bird, the input 113c of the circuit 113 pours up the high pogol, the handset 102 is already koinon pulse to the coil 100b of the channel 106 from, for dom reason that the call with dom handset 102 via dio trunk line A is not interrupted. Therefore, the signal 106 remains in the solomonic orston switching state, only when the circuit 113 of the transistor 110 has passed through without interruption after the contact 109.2 has been closed, is the handset 102 connected to the remote mode B. The tollbooth on the Tolofon apparatus 101 may then go into the running gosprilch on the Loitung B uinschalton and, for the time being, that the line be frolgomacht or may return the handset 102 to its receiving host.

6. The participant in the Tolefonapparat 101 accepts the handset 102, while the relay 106 is in its Zweiton scolded state and the Fornmeldotoltung D is already bosotzt by olnon call with dom Tolefonapparat 16.

In this folio, as in case 3 in the previous boschriobon, the output 11c of the voltage-doping switching circuit 11 and, therefore, the input 113c of the switching logic 113 goes high in response to the sound of the contact 9.1.

At the moment when the input 113c of the circuit 113 goes high, the input 113j of the circuit 113 is low, because the handset 102 is not in use, the circuit 113 outputs a current pulse to the coil 106a dos Relay 106 whether, which assumes its orston switching state for this reason.

As was written in case 1 in the previous one, a short moment after the contact is closed, the circuit 113 also drives the transistor 10 and indirectly connects its input 113d to its output 113k. The handset 2 is connected for this reason via don Sprechkrelu 6 with the telecommunication line A.

If the telecommunication line A is free, the tell-noun can then dial the number it wishes to call. However, if the trunk line A is already busy by a call to the dom telephone set 15, the subscriber to the trunk can engage in this call to request that the line be cleared or he can return the handset to its pickup moment.

Since, at the moment when the input 113c of the circuit 113 assumes a high level, the input 113j of the circuit 113 is high because the handset 102 is in use, the circuit 113 does not give a pulse to the coil 106a of the relay 106, for the reason that the ongoing conversation with the handset K 'on the Fernmoldeloitung A is not interrupted.

The relay 106 therefore remains in its second switching state when the circuit 113 turns on the transistor 10 a moment after the contact 9.2 has been closed, and the handset 2 is therefore connected to the telecommunications line B,

The subscriber to the telephone set 101 can then turn on the current call on the trunk line B and request that the line is cleared or he can put the handset 2 on his receiving element.

6. The subscriber to the telephone set 101 receives the handset 102 while the relay is in its second switching state and the trunk line A is already busy by a call to the telephone set 15.

In this case, as described in the foregoing case 4, the output 111c of the span detection circuit 111 and thus the input 113i of the circuit 113 goes high in response to the closing of the contact 109.1.

Since the instant in which the input 113i of the circuit 113 goes high, the input 113 of the circuit 113 is low because the handset 2 is not in use, the circuit 113 outputs a current pulse to the coil 106a of the relay 106 , which therefore assumes its first switching state.

As described in the previous case 2, the circuit 113 also drives the transistor 110 a short time after the contact 109.2 has been closed, and indirectly connects its input 113d to its output 113k. For this reason, the handset 102 is connected to the telecommunication line B via the speech circuit 105.

If the trunk line B is free, the subscriber can dial the number he wishes to call. However, if the trunk line B is already busy by a call to the telephone set 16, the subscriber on the telephone set 101 can engage in this call and request that the line be cleared or he can put the handset 102 back on his seat.

If, at the moment when the input 113i of the circuit 113 goes high, the input 113e of the circuit 113 is high because the handset 2 is already in use, the circuit 113 does not give a pulse to the coil 106a of the relay 106 from, for the reason that the ongoing conversation with the handset 2 via the trunk line B is not interrupted. The relay 106 remains in its second state, and when the circuit 113, one moment after the contact 109.2 is closed, the transistor 110 through, the handset 102 is connected to the telecommunication line A. The subscriber on the telephone set 101 can then turn on the ongoing call on the trunk line A and request that the line be cleared or he can place the handset 102 on the receiving element.

It can be seen that the control circuit 113 of the telephone set 101 according to FIG. 4, as well as the control circuit 13 of the telephone set 1 according to FIG. 1, can be arranged in such a way that the transistor 110 or the transistor 10 is not turned on, after a subscriber picks up the handset 2 or handset 102 to place a call while both trunk lines A; B are occupied. In such a case, the control circuit 113, as well as the control circuit 13, advantageously comprises means which trigger a visual and / or audible signal to indicate to the subscriber that he does not use the telephone set 101 to make a call.

It will also be appreciated that the control circuit 13 may be made different from that which has been described or that it may even be replaced by a microcomputer programmed to meet the same requirements. The same is applicable to the circuit 113. It is also evident that the

Before this invention was not carried out on the execution of Varlanton by Telofonapparaton, wnlctio were hlor bocchrlobon.

Thus, for example, the invention may also have been offered to olonom Tolofonapporot application to Indonus, which is said to be connected with mohr as two communication lines, or more likely than two independent handsets.

The invention may also be applied to donors in cases prewonning, which are described in connection with FIGS. 1 and 2, but which have basic characteristics in the case of Donolio Tolofonapparato, and which are housed in the Gohttuso dos handsets of Allo Bostancltollo cllosos Apparatos ,

Bn! dorartlgen cases, contacts dio 9.1; 9.2 entsprochond Fig. 1, z. B. by oinon push button has been actuated odor by oinon slide switch.

The present invention is also applicable to solcho fallout, in the case of which the Grunc'gorrit dos Tolofonopparatos themselves oinon odor boklo handset bildot odor ersotzt, as in dom Telofonappai at, described in dom domch US Patent 4,817,138.

Claims (1)

Tolefonapparat ausgeologt to be connected to a plurality of telecommunications lines, each of which may have a free or occupied state and each capable of oin callsign to transmit, comprising an electroacoustic unit, welcho oin microphone and a handset and Switching means responsive to each said call sign to selectively connect said oloktroakustischo Einholt to the trunk line carrying said call sign, further comprising means for generating oinosignals indicative of the use of said electroacoustic unit and means for generating a call A busy signal that responds to the line associated with said electroacoustic unit being bosetzt and said switching means is further capable of responding to the use of said signal, indicates the event and to which Busy signal to the g to connect the electroacoustic unit to another of the said telecommunication lines. For this 4 pages drawings