GB2134750A

GB2134750A - Bilateral telephone call transfer apparatus

Info

Publication number: GB2134750A
Application number: GB08326549A
Authority: GB
Inventors: Nakamichi Sasano
Original assignee: NIHON RESUKO KK
Current assignee: NIHON RESUKO KK
Priority date: 1983-01-28
Filing date: 1983-10-04
Publication date: 1984-08-15
Also published as: GB8326549D0; GB2134750B; JPS59138157A; AU3031984A; AU580927B2

Abstract

A telephone system is provided with a bilateral telephone call transfer apparatus (9) which is capable of bilateral transfer of a call from a receiving telephone set (4) to a transmitting telephone set (5) and vice versa. <IMAGE>

Description

SPECIFICATION Bilateral telephone call transfer apparatus This invention relates to a telephone call transfer apparatus and, more particularly, to a telephone call transfer apparatus which is capable of bilateral transfer of a call from a receiving telephone set to a transmitting telephone and vice versa.

An apparatus which can automatically transfer a call directed to an office to an extension office when no one is present in the office, commercially available under a trade name "telephone call transfer device".

Fig. 1 shows a well-known example of the apparatus. Referring to the Figure, reference numeral 1 designates a calling telephone set (i.e., a public telephone set), 2 a repeater station to which the calling telephone set 1 belongs, 3 a central telephone exchange office, 4 a receiving telephone set in an office called from the calling telephone set 1, 5 a transmitting telephone set in the same office, 6 a transfer section connected to the terminals of the receiving and transmitting telephone sets 4 and 5, 7 a repeater station to which a destination telephone set in an extension office belongs, and 8 the destination telephone set in the extension office.

In the well-known system of Fig. 1, when the receiving telephone set 4 is called from the calling telephone set 1, said receiving telephone set 4 is called via the repeater station 2 and central telephone exchange office 3. When nobody is in the office, the transfer section 6 is operated under a well-known theory of transfer, causing an automatic dial number to be transmitted from the transmitting telephone set 5 to the central telephone exchange office 3 to call the destination telephone set 8 via the repeater station 7. In this way, communication between the calling telephone set 1 and destination telephone set 8 is made possible.

If push-button telephone sets are used for said receiving and transmitting telephone sets 4 and 5 in the well-known system of Fig. 1, it is possible to permit transfer of a call not only from the receiving telephone set 4 to the transmitting telephone set 5 but also vice versa by merely providing a simple adopter.

That is, when the transmitting telephone set 5 is called from the calling telephone set 1, the call can be transferred to said destination telephone set 8.

This means that a transfer of a telephone call is possible when any one of a plurality of telephone sets having respective enlisted telephone members is called. A more important advantage obtainable is that it is possible to desirably select a destination region such that a transfer to a region a can be obtained by calling one of the enlisted telephone sets and a transfer to a different region b can be obtained by calling any other telephone set.

An object of the present invention, accordingly, is to provide a bilateral telephone call transfer apparatus, which can transfer a call from the receiving telephone set to the transmitting telephone set and vice versa.

Another object of the present invention is to provide a bilateral telephone call transfer apparatus, which permits selection of a destination region.

In the drawings, Fig. 1 is a block diagram showing a prior art telephone call transfer apparatus; Fig. 2 is a block diagram showing a telephone call transfer apparatus according to the present invention; Figs. 3 and 4 are block diagrams illustrative of functions obtainable according to the present invention; and Fig. 5 is a circuit diagram showing the main circuit of the apparatus according to the present invention.

An embodiment of the present invention will now be described with reference to the drawings.

Fig. 2 and following Figures illustrate an embodiment of the present invention. Like the case of Fig. 1, reference numeral 1 designates a calling telephone set (i.e., a public telephone set), 2 a repeater station to which the calling telephone set belongs, 3 a central telephone exchange office, 4 a receiving telephone set in an office called from the calling telephone set 1, 5 a transmitting telephone set in the same office, 6 a telephone call transfer section connected to the terminals of the receiving and transmitting telephone sets 4 and 5, 7 a repeater section to which a destination telephone set in an extension office belongs, and 8 the destination telephone set in the extension office. A bilateral telephone call transfer apparatus 9 is provided between the receiving and transmitting telephone sets 4 and 5.

Fig. 3 and following Figures illustrate said bilateral telephone call transfer apparatus 9 in detail. Reference numerals 10 and 11 designated call detecting section, 1 2 a reception said transmission switch, and 1 3 a relay driving section. The call detecting section 10 includes a photocoupler 14 and an output transistor 1 5. 16 input side terminals of said receiving detector 10 are connected to the receiving telephone set 4.

The call detecting section 11 includes a photocoupler 17 and an output transistor 18 and 1 9 input side terminals. Input terminals 19 is transferred to the transmitting telephone set 5.

Reference numerals 20 and 21 designate AND gates provided in the reception/transmission switch 12, 22 a relay driver therein, and 23 a relay coil therein. Reference numeral 24 designates a visual display section for visually displaying the state of transfer of a call reception by the transmitting telephone set 5 and the state of transfer of a cell transmission by the receiving telephone set 4. Reference numeral 25 designates a light-emitting diode for visually displaying the state of call reception by the transmitting telephone set 5 and the state of opposite call transmission by the receiving telephone set 4, 26 a light-emitting diode for visually displaying the state of call reception by the receiving telephone 4 and the state of normally call transmission by the transmitting telephone set 5.Reference numeral 27 designates terminals connected to the receiving telephone set 4, 28 terminals connected to the transmitting telephone set 5, 29 receiving side terminals connected to the receiving side of the telephone call transfer section 6, 30 transmitting side terminals connected to the transmitting side of the telephone call transfer section 6. Reference numerals 31 and 32 designate contacts of the reception/transmission switch operable by a relay coil 23. Reference numeral 33 designates an office.

Operation of an embodiment of the present invention describes as follows; When the receiving telephone set 4 is called from the calling telephone set 1, a call signal is transmitted to the receiving telephone set 4 via the repeater station 2 and central telephone exchange office 3. When nobody is in the office 33 and the apparatus is set in a transfer state at this time, the photocoupler 14 detects a bell signal and supplies a control signal to the output transistor 1 5. As a result, a flip-flop consisting of the AND gates 20 and 21 are inverted, so that the AND gate 20 produces an output.The relay driver 22 is actuated by the output of said AND gate 20, causing current to flow through the relay coil of the relay coil 23 to switch the contacts 31 and 32 of the reception/transmission switch (to the state as shown by phantom lines in Fig. 3). As a result, the bell signal is transmitted to the receiving side terminals 29. Thus the transfer section 6 transmits its automatic dial number from the transmitting side terminals 30 to the central telephone exchange office 3 to call the repeater station 7 on the basis of the well-known theory of transfer. The signal is thus transferred to the telephone line of the telephone set 8 in the extension office. Now, communication between the calling telephone set 1 and telephone set 8 in the extension office can be made.

When the handset of the calling telephone set 1 is hooked up after the communication is over at this state, the transfer section 6 receives a disconnecting signal from the repeater station 2 and central telephone exchange office 3 so that it is restored to the initial state. At this time, the contacts 31 and 32 of the reception/transmission switch 12 of the bilateral telephone call transfer apparatus 9 remain in the state of the phantom lines.

When the transmitting telephone set 5 is called from the calling telephone set 1, a call signal is transmitted to the transmitting telephone station 5 via the repeater station 2 and central telephone exchange office 3. The photocoupler 1 7 detects the bell signal and supplies a control signal to the output transistor 1 8. As a result, the flip-flop consisting of the AND gates 20 and 21 is inverted so that the AND gate 21 produces an output. At the same time, the control signal of the relay driver 22 is cut off, thus cutting off the current through the relay coil 23. The contacts 31 and 32 of the reception/transmission switch 12 are thus switched to the state shown by solid lines.

As a result, a bell signal is added to the receiving side terminals 29. The transfer section 6 thus transmits its automatic dial number of the central telephone exchange office 3 to call the repeater station 7 on the basis of the well-known theory of transfer. As a result, the signal is transferred to the telephone line of the telephone set 8 in the extension office. Now, communication between the output transistor 1 8 and telephone set 8 in the extension office can be made.

As has been described, in the system commercially available as the telephone call transfer apparatus, in which a telephone call directed to office when nobody is therein is transferred to a telephone set in an extension office automatically, can transfer only a telephone call addressed to a particular telephone set and cannot transfer calls addressed to other telephone sets.

Where push-button telephone sets are used as the receiving and transmitting telephone sets in the office, it is not only possible to transfer a telephone call received by the receiving telephone set but it is also possible to transfer a telephone call received by the transmitting telephone set from this set to the receiving telephone set by merely providing a single adopter.

That is, transfer to the telephone set in the extension office is possible even when the transmitting telephone set is called from the calling telephone set. This means that a transfer of a telephone call is possible when any one of a plurality of telephone sets having respective enlisted telephone numbers is called. A more important advantage obtainable is that it is possible to desirably select a destination region such that a transfer to a region a can be obtained by calling one of the enlisted telephone sets and a transfer to a different region b can be obtained by calling any other telephone set.

Claims

1. In a telephone system having a receiving telephone set and a transmitting telephone set, in which a telephone call from a calling telephone set directed to the receiving telephone set can be transferred from the transmitting telephone set to a destination telephone set by automatic dialing, a bilateral telephone call transfer apparatus comprising connecting to both said receiving and transmitting telephone sets and destination telephone set capable of causing transfer of a telephone call directed from a calling telephone set to said transmitting telephone set to a destination telephone set.

2. In a telephone system having a receiving telephone set and a transmitting telephone set, in which a telephone call from a calling telephone set directed to the receiving telephone set can be transmitted from the transmitting telephone set to a destination telephone set by automatic dialing, a bilateral telephone call transfer apparatus comprising connecting to both said receiving and transmitting telephone sets and destination telephone set and including a reception/transmission switch capable of being switched by a call signal so as to effect transfer of a telephone call from a calling telephone set directed to said transmitting telephone set to a destination telephone set

3. A bilateral telephone call transfer apparatus susbtantially as hereinbefore described with reference to Figures 2 to 5 of the accompanying drawings.

4. The features herein described, or their equivalents, in any patentably novel selection.