Call-routing device

• US 4,645,879 A
• Filed: 02/08/1985
• Issued: 02/24/1987
• Est. Priority Date: 02/08/1985
• Status: Expired due to Fees

• Current Assignee: Shawmut Bank of Boston NA A National Banking Association
• Original Assignee: Telelogic Software Singapore Pte Limited (International Business Machines Corporation)
• Inventors: Simmons, Richard M.
• Primary Examiner(s): Dwyer, James L.
• Application Number:
  US06/700,020
• Time in Patent Office: 746 Days
• Field of Search: 179/18 BE, 179/18 BA, 179/18 B, 179/90 B, 179/90 BB, 179/90 BD, 179/18 AD, 179/27 FG, 179/27 FH
• US Class Current: 379/355.01
• CPC Class Codes: H04M 3/58 Arrangements for transferring received calls from one subscriber to another; Arrangements affording interim conversations between either the calling or the called party and a third party substation line holding circuits H04M1/80
• CPC Class Codes: H04Q 3/625 Arrangements in the private branch exchange

Abstract

Telephone calls from an extension (32) on a private branch exchange (PBX) (14) are directed by an automatic telephone dialer (12a) to an outside line (18) of a local operating company or to a dedicated line (22) connected to the facilities of a specialized common carrier. The dialer is connected to an extension line (36) simply as another extension. A call from an extension (32) requesting an outside line is directed to the extension occupied by the dialer (12a), and a ring detector (40) detects the resultant ringing signal and alerts a controller (44). The controller sends a dial tone to the calling extension (32) and records the resultant dialed digits. It then momentarily interrupts its off-hook signal to cause the PBX to place the calling station (32) on hold and dials the appropriate destination. Once the dial has been replaced, it "hangs up," causing the PBX to connect the calling extension (32) to the destination that the automatic dialer has called.

Claims

1. A telephone dialer for routing calls placed on a telephone system that includes a plurality of extension lines and a plurality of outside lines connected to facilities of common carriers and that further includes switching circuitry that makes connections between extension lines and between extension lines and outside lines, the switching circuitry being of the type that responds to a flashing signal from a called extension line by placing a calling extension line on hold and presenting a dial tone to the called extension line, that thereafter connects the called line to a third line designated by signals from the called line, and that thereafter connects the calling line to the third line in response to a subsequent removal of an off-hook signal from the called extension line, the telephone dialer comprising:

A. a dialer port, adapted for connection to an associated extension line, for receiving signals from the extension line and transmitting signals thereover;

B. a ring detector connected to monitor signals received over the dialer port and generate a call signal when the dialer port carries ringing signals caused by the placing of a call from a calling extension to the dialer;

C. a termination circuit operable to place a loop termination across the dialer port and thereby send an off-hook signal to the switching circuitry, the termination circuit further being operable to remove the loop termination from the dialer port and thereby interrupt the off-hook signal;

D. a control circuit connected to receive call signals from the ring detector, operate the termination circuit, and send and receive signals over the dialer port, the control circuit responding to call signals from the ring detector by operating the termination circuit to place a loop termination across the dialer port and by sending a dial tone to prompt a user at a calling extension to send dial signals that represent a destination code, the control circuit further detecting the dial signals from the calling extension and storing the destination code represented thereby, sending the flashing signal over the dialer port to cause the switching circuitry to put the calling extension on hold, selecting a common carrier over which to place the call dialed from the calling extension, sending signals necessary to place a call, over the selected common carrier, to the destination station indicated by the destination code, and operating the termination circuit to remove the termination loop from the dialer port so as to release the line connected to the destination station and cause the switching circuitry to connect that line to the calling extension line.

2. A telephone dialer as defined in claim 1 wherein:

A. the flashing signal to which the switching circuitry responds is a momentary interruption in an off-hook signal; and

B. the control circuit sends the flashing signal over the dialer port by operating the termination circuit to remove the loop termination momentarily from the dialer port.

3. A telephone dialer as defined in claim 2 wherein the termination circuit includes a hybrid-and-loop-termination circuit including the loop termination and also includes a switch for connecting the hybrid-and-loop-termination circuit to the dialer port, the switch being operable by the control circuit to place the hybrid-and-loop-termination circuit across the dialer port and to remove the hybrid-and-loop-termination circuit from the dialer port.

4. A dialer as defined in claim 3 wherein the hybrid-and-loop-termination circuit includes a common port, a receiver port, and a transmitter port, the common port being connected to the switch for connection and disconnection of the common port to and from the dialer port, the hybrid-and-loop-termination circuit placing on the common port signals applied to the transmitter port and applying to the receiver port signals received from the dialer port over the common port.