JPS6121028B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a central office line transfer system in a private branch exchange.

Conventionally, a callback transfer connection method has generally been used as a central office line transfer method in private branch exchanges.

For example, as shown in the relay system in FIG. 1, the telephone is connected to the office line trunk COT (hereinafter referred to as ``COT'') by a transfer extension line EXTA (hereinafter referred to as ``EXTA'') and is in a talking state. Here, when EXTA attempts to transfer to the forwarded extension EXTB (hereinafter referred to as "EXTB"), COT first captures the call back trunk CBT (hereinafter referred to as "CBT") by dialing any one digit. . Next, EXT A is
Dial the EXT B extension and CBT will call EXT.
B's extension number information is received and stored. When the extension number information has been accumulated in this way, CBT marks marker M.
(hereinafter referred to as "M"), a line link frame LLF path (hereinafter referred to as "LLF") is formed, and EXT B is connected to CBT.Next, CBT
When EXT B goes off-hook due to the ringing signal sent from EXT A-LLF-COT-CBT-
A callback call is made via the LLF-EXT B route. After EXT A notifies EXT B that it will transfer to the central office line, when it goes on-hook, CBT starts M again and restores LLF. When M identifies that it is a transfer connection, it restores the LLF and then forms a line link frame LLF route (hereinafter referred to as "LLF"). Therefore, CBT confirms that EXT B has been reconnected via the route EXT B-LLF-COT-CBT, and then connects COT.
- Open the CBT and restore. In this way
EXT B is connected to COT via LLF to complete the transfer connection.

The conventional system as described above has the disadvantage that the operations required to call the transferred extension are cumbersome. In particular, in a small-capacity private branch telephone exchange where all extension lines are installed on the same floor and notification to transfer to a central office line can be given verbally without having to go through the trouble of making a callback connection, this method impedes smooth operation. It could become a problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide a central office line transfer system that eliminates the serious drawbacks of the small-capacity private telephone exchange described above and allows for smooth operation.

In order to achieve this object, the present invention accommodates two systems of trunk switch terminals (hereinafter referred to as "switch terminals") in a central office line trunk, and when one switch terminal is used by a forwarding extension line, the other switch terminal is covered. By making it available for use as a forwarding extension, the forwarding extension that has verbally notified the forwarding extension that it will be forwarded to a central office line can dial a predetermined specific number while the forwarding extension continues the forwarding operation. For example, the other switch terminal is used to connect to the central office line trunk, and one switch terminal to which the transfer extension is connected is opened to complete the central office line transfer.

An embodiment of the present invention will be described below with reference to FIGS. 2 and 3.

FIG. 2 shows the relay system of the present invention (the same reference numerals are used for the same parts in FIG. 2 as in FIG. 1). In FIG. 2, EXT A is in a talking state connected from switch terminal A to COT via the LLF path. Here, when EXT A attempts to perform a central line transfer to EXT B, it first verbally notifies EXT B that it will perform a central line transfer. Next, while EXT A is performing a predetermined transfer operation, COT detects it and continues to form a selection route for switch terminal B.
When EXT B hears the notification of central line transfer and dials a predetermined specific number after making a dial tone connection via off-hook, EXT B will be transferred from the selected route of switch terminal B formed within COT under the control of M.
The LLF path is closed. COT is EXT B-
EXT B via LLF-Switch terminal B-COT path
After confirming that EXT A is connected, the LLF route to which EXT A is connected is restored. In this way, EXT B is connected from switch terminal B to COT via the LLF path, and the station line transfer is completed. The transfer operation performed by EXT A is EXT
A telephone with a button is adopted as the telephone of A, and a method is used in which the selection route of the switch terminal B is formed only while the button is pressed down.

Next, an embodiment of the present invention will be explained in detail with reference to FIG.

Transfer extension EXT A (hereinafter referred to as "EXT A")
is connected to the office line trunk COT (hereinafter referred to as ``COT'') via a line link frame (hereinafter referred to as ``LIF(A)''), and is in communication with the office line. EXT A is the transferred extension EXT B (hereinafter "EXT
EXT A's transfer button operation detection relay RLO is activated only while the transfer button attached to the telephone is pressed after notification of transfer to the central office line (referred to as "B").
A telephone circuit - LIF (A) - A1 terminal - EXT
A's telephone loop monitoring relay operates on the path of A0 coil - RLO coil - battery. While this transfer button operation detection relay RLO is operating, the selection route of line link frame B (hereinafter referred to as LIF (B)) is the marker (hereinafter referred to as ``MKB'') - TS1 terminal - H1 contact - EXT B telephone loop. Monitoring relay A
BL ⁰ contact of relay B1 operated by 1 - rO ⁰ contact - LLF (B) - Selection confirmation relay LOT coil -
TRF terminal - MKR continues to form. Then EXT
When B establishes a dial tone connection using a known method and dials a predetermined specific number,
MKR is started. MKR confirms that it is a central office line transfer because a specific number has been dialed, and closes LLF (B) using the previously formed selection route of LLF (B). At this time, LLF
The OT relay inserted in the selected route of (B)
Since it is operated from the MKR, the COT office line side communication path is switched to the EXT B side communication circuit by the OT ³ and OT ⁰ contacts. The OT relay has 2 coils.
One coil of the winding functions for operation, and the other coil functions for self-maintenance. When this OT relay operates, the LLF (A) holding circuit through the path of ground air - ot ⁰ contact - bo ¹ contact - C1 terminal is disconnected and LLF
(A) will be restored. At the same time, EXT A's telephone loop monitoring relay A0 is also restored. When the LLF (B) path is closed, EXT B's telephone loop monitoring relay A1 connects the EXT B's transfer button operation detection relay R1 to the coil - LLF (A) selection confirmation relay OTR.
ot ¹ contact - A1 coil - b ² contact - LLF (B) -
It operates on the path of EXT B telephone loop - LLF (B) - A2 terminal - A1 coil - RL1 coil - battery, and it is confirmed that EXT B is connected to COT. When the B1 relay operates due to the operation of the A1 relay, the path of the ground air - ot ⁰ contact - BL ¹ contact - C2 terminal
While holding LLF (B), earth air-bl ⁶ contact-b
The B0 relay holding circuit with the ⁰² contact-B0 coil-battery path is disconnected, the B0 relay is restored, and the office line transfer connection is completed.

With the above operation, the station line becomes COT and LLF (B)
Since it was connected to EXT B via
A call will begin. EXT B is EXT again
The same procedure as described above can be performed when retransferring to A or another extension.

Note that if there are two forwarding extensions at the same time for one forwarded extension, these two
From the perspective of the urgency and necessity of transfer to the central office line, it may be determined through verbal discussion which of the two forwarding extensions should be given priority for forwarding to the central office line. In this case, all you need to do is hold down the transfer button for the forwarding extension that will be transferred to the central office line first, and you can undo the forwarding button for the forwarding extension that will be transferred to the central office line later. good. For transfer extensions that will be transferred to the local line later, after the call that was previously transferred to the local line has ended, the call can be transferred to the local line by pressing the transfer button again. Here, if no agreement is reached between these two forwarding extensions, one of the forwarding extensions will be selected and the transfer will be made to the central office line, but which forwarding extension to select preferentially is determined by By combining the present invention with known techniques (for example, the techniques described in Japanese Patent Publication No. 47-2126, Japanese Patent Publication No. 47-25725, etc.), the present invention can be easily realized without requiring special inventive power. It is obvious that this technique can be determined, and there is no need to explain the technique here.

As described above with respect to the embodiments of the present invention, according to the present invention, central line transfer can be performed with a simple operation, so that operability can be improved. Note that even if the method of the present invention is added to the conventional method, central office line transfer via call back transfer connection is possible.

[Brief explanation of the drawing]

Figure 1 is a relay system diagram for conventional station line transfer.
FIG. 2 is a relay system diagram of the present invention, and FIG. 3 is a circuit diagram of an embodiment of the present invention. EXT A...Forwarding extension, EXT B...Forwarded extension, LLF...Line link frame, M MKR
...Marker, COT...Central line trunk, CBT...
Callback trunk, A, B... Trunk switch terminal.

Claims (1)

[Claims] 1. In the central office line transfer method of a private telephone exchange that transfers central office lines between internal lines, the system has first and second extension call terminals connected to the first and second trunk switch terminals of the line link frame, respectively. a second trunk switch terminal that selects the second trunk switch terminal only while a first transfer extension connected to the first trunk switch terminal via the central office line trunk and the line link frame is performing a transfer operation; a first selection of selecting the first trunk switch terminal only while a second transfer extension is performing a transfer operation while connected to the second trunk switch terminal via the selection route and the line link frame; and means for forming a route to the central office line trunk, and when the called forwarding extension, which has been notified by the first forwarding extension that the call will be forwarded to the central office line, dials a predetermined specific number, the second forwarding extension When the called forwarding extension connected to the trunk switch terminal of the first trunk switch terminal is restored and the called forwarding extension is notified that the call will be forwarded to the central office line from the second forwarding extension dials a predetermined specific number. is connected to the first trunk switch terminal and the second trunk switch terminal is restored to complete the transfer connection of the central office line trunk alternately.