Remotely programmable call diverter

• US 3,959,600 A
• Filed: 04/28/1975
• Issued: 05/25/1976
• Est. Priority Date: 04/28/1975
• Status: Expired due to Term

• Current Assignee: Arlington Trust Co. (Lawrence, Massachusetts) (Bank of America Corp.)
• Original Assignee: Arlington Trust Co. (Lawrence, Massachusetts) (Bank of America Corp.)
• Inventors: Sousa, Henry P.
• Primary Examiner(s): Robinson, Thomas A.
• Application Number:
  US05/572,027
• Time in Patent Office: 393 Days
• Field of Search: 179/18 BE, 179/18 BA, 179/18 BD, 179/18 B, 179/84 L, 179/84 R, 179/18 ES
• US Class Current: 379/157
• CPC Class Codes: H04M 1/006 Call diverting means
• CPC Class Codes: Y10S 379/914 Programmable telephone component

Abstract

A remotely programmable telephone call forwarding and switching device, or call diverter, having a ring detector with memory capability, an improved dial tone detector, an improved bridging circuit, a capability to program its memory locally and remotely and to confirm the newly programmed number, capable of utilization within telephone systems having a wide diversity of equipment and operational capability, including compatibility with touch and pulse dial systems, and an accessory touch dial encoder for use with rotary dial telephones.

Claims

1. An improved remotely programmable automatic telephone call forwarding and switching device for connection to two telephone lines from at least one central exchange and for switching incoming calls on the first one of said lines to outgoing calls on the second of said lines thus diverting incoming calls to a predetermined telephone number programmed by the subscriber comprising:

improved ring detection means connected to each of said two lines, detecting only ringing signals on each of said lines and retaining an indication of said ring until the switching function initiated by said ring is completed;

first circuit means connected to said ring detection means to determine sequence of operations depending on which line a ring has been detected on;

line seizure means to seize each of said telephone lines;

improved dial tone detection means to detect the presence of a dial tone on each of said subscriber lines;

programmable memory means capable of storing representations of telephone numbers to which incoming telephone calls are to be diverted;

tone decoding means to convert touch dial tone signals to serial pulse data for said programmable memory means;

second circuit means for programming said memory means via said tone decoding means and for reading the pulse information out of said memory means to the dialing means of the second of said telephone lines, to dial out a telephone call to the telephone number stored in said memory;

improved audio bridging means to establish an audio path between the first of said telephone lines and the second of said telephone lines;

automatic bridging means to determine when an audio path between said telephone lines is to be established;

an interrupt means to pulse the first of said bridged lines which is activated to determine the termination of the call on the first of said bridged lines and to force the return of said dial tone;

an abort circuit means to reset said switching device after completion of a switching function for any reason;

improved timing means connected to said ring detection means, said decoding means, said interrupt means, said read means, said dial tone detection means and said automatic bridging means to activate and terminate the operation of said means in a timed sequence compatible with telephone company equipment and operational standards.

2. The device of claim 1 wherein said improved ring detection means further comprises:

a ring detection circuit means connected to each of said telephone lines;

a variable resistor optically coupled to a neon tube which presents a relatively high resistance in the absence of a ring signal and low resistance in the presence of a ring signal, thereby detecting a ring signal;

a silicon controlled rectifier which is controlled by said optically coupled neon tube and variable resistor and is fired by the increased voltage resulting from the detection of a ring, thereby retaining evidence of the detection of a ring.

3. The device of claim 1 wherein said first circuit means further comprises:

means to determine which of said two telephone lines is ringing;

means to determine whether there is data in said programmable memory upon the detection of a ring on the first of said telephone lines;

means to activate said abort means upon determination of an absence of data in said programmable memory;

means to activate a timed sequence of steps to switch and forward an incoming call upon the detection of a ring on the first of said telephone lines and upon the determination of the presence of data in said programmable memory;

means to activate a timed sequence of steps to reprogram said programmable memory upon the detection of a ring upon the second of said telephone lines.

4. The device of claim 1 wherein said improved dial tone detection means further comprises:

an operational amplifier which filters out signals above eight hundred hertz;

a dual retriggerable monostable multivibrator, one part of which is adjusted to detect signals above one hundred eighty hertz whose frequencies are greater than its own frequency;

the second part of said dual retriggerable monostable vibrator adjusted to detect continuous tones of a certain duration compatible with the standards of duration of telephone company;

the satisfaction of both parts of said dual retriggerable monostable vibrator resulting in the detection of a dial tone.

5. The device of claim 1 wherein said programmable memory further comprises:

a shift register containing six registers;

each of said registers having a 32 bit capacity in the serial decimal numbering system;

said memory being a read-write memory.

6. The device of claim 1 wherein said tone decoding means further comprises:

a plurality of phase lock loops each of which is calibrated to detect one tone of a touch dial signal;

each of said phase lock loops having a voltage controlled oscillator whose frequency of oscillation is controlled by varying the values of resistors and capacitors.

7. The device of claim 1 wherein said automatic bridging circuit further comprises:

a dial tone detection means activated upon completion of a dial out on the second of said telephone lines after the detection of a ring on the first of said telephone lines;

said dial tone detection means being capable of detecting any audio noise on said second telephone line;

the detection of said audio noise resulting in activation of said audio bridging circuit;

a timing device in said automatic bridging circuit which activates said audio bridging circuit in the absence of the detection of audio noise after a predetermined lapse of time.

8. The device of claim 1 wherein said audio bridging means further comprises:

two bridging transformers each isolated from said two telephone lines;

an audio amplifier between said transformers and connected to the secondary of each of said transformers;

said transformers separated by said audio amplifier providing an automatic impedance matching between said two telephone lines.

9. The device of claim 1 wherein said improved timing means further includes:

a timer circuit having multiple inputs and outputs for varying the duration of its operation.

10. The device of claim 1 further including a touch dial pad for transmitting tone signals to said tone decoder locally over wires connecting said pad to said device and remotely over any telephone interconnected to the second of said telephone lines.

11. The device of claim 1 wherein said abort circuit means further comprises:

an instantaneous power-up network means itself comprising a plurality of resistors, capacitors, rectifiers, diodes and transistors, the function of which is to provide full electrical power immediately to the call diverter, when it is connected to an external source of power.