US Patent No: 4,809,317

Number of patents in Portfolio can not be more than 2000

Telephone line exclusion device

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ATTORNEY / AGENT: (SPONSORED)

Importance

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Abstract

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A device is disclosed for use on a telephone line where there is two or more telephones or other instruments connected in parallel to the same telephone line whereby when one of the instruments goes off-hook (in a telephone, raises the receiver) the telephone line exclusion device automatically locks out all other instruments connected in parallel with the instrument that went off-hook. Such a result is achieved by a pair of interconnected two-coil polarized normally closed reed relays which interface the incoming telephone line and the two instruments. The two lines which normally connect to each instrument on the telephone line utilizes the normally closed contacts of one relay to energize the coils of the other relay and thereby inhibit the other instrument on the telephone line by opening the normally closed contact of the second relay which is in line with the other instrument. Upon the first instrument going on-hook (in a telephone, returning the receiver to the cradle), the telephone line exclusion device returns to its quiescent state where either instrument upon the line may be utilized.

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First Claim

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Patent Owner(s)

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International Classification(s)

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Inventor(s)

Inventor Name Address # of filed Patents Total Citations
Howe, Paul R Nacogdoches, TX 2 19
Morris, Michael D Cedar Rapids, IA 129 3269

Cited Art Landscape

Patent Info (Count) # Cites Year
 
HASHIMOTO CORPORATION (1)
* 4,660,218 Apparatus for switching telephone line a response device, a data terminal or a telephone 107 1985
 
HORLOGERIE PHOTOGRAPHIQUE FRANCAISE LE BOUCHET (1)
* 4,591,662 Telephone set-computer terminal assembly with a single decimal keyboard and a switchable local power supply 18 1984
 
HUGHES, RAYMOND F. 6601 WESTWOOD BLVD. E. TAMARAC, FL (1)
* 4,604,499 Computer telephone access security processor 27 1984
 
NORTEL NETWORKS LIMITED (1)
* 4,378,470 Interface circuits for connection to non-dedicated telephone lines 157 1981
 
Novation, Inc. (1)
* 4,367,374 Modem telephone interface circuit 45 1981
 
Prentice Corporation (1)
* 4,596,021 Modem for switching between voice and data communications on a single telephone call 115 1984
 
Robinton Products, Inc. (1)
* 4,640,988 Telephone interrupter 16 1984
 
Timex Corporation (1)
* 4,394,540 Remote meter reader and method for reading meters over non-dedicated telephone lines 53 1981
 
Other [Check patent profile for assignment information] (2)
* 4,444,999 Automatic electronic disconnector for subscriber terminal equipment 47 1982
* 4,469,917 Time synchronized data transmission system 24 1982
* Cited By Examiner

Patent Citation Ranking

Forward Cite Landscape

Patent Info (Count) # Cites Year
 
CANON KABUSHIKI KAISHA (3)
* 5,142,567 Communication apparatus having alternate message communication 6 1991
* 5,317,629 Data communication apparatus connectable with a plurality of telephone sets and a telephone line 18 1991
* 5,414,764 Communications apparatus 10 1994
 
INTEL CORPORATION (2)
* 6,882,716 Local control of call features in a telephone system 1 2001
7,177,410 Local control of call features in a telephone system 0 2005
 
Omega Electronics Inc. (2)
* 5,796,789 Alerting device for telephones 9 1997
* 6,002,747 Telephone privacy and alerting device 10 1997
 
AASTRA TECHNOLOGIES, INC. (1)
* 6,061,438 Extension-in-use exclusion apparatus 9 1994
 
HEWLETT-PACKARD DEVELOPMENT COMPANY, L.P. (1)
* 4,987,586 Modem-telephone interconnect 31 1987
 
KABUSHIKI KAISHA TOSHIBA (1)
* 4,939,769 Cordless telephone system 2 1988
 
QWEST COMMUNICATIONS INTERNATIONAL INC. (1)
* 5,978,469 Apparatus for telephone extension control 34 1997
 
Shirohato Yakuhin Co., Ltd. (1)
* 5,206,898 Transmission control unit 9 1991
 
THOMSON LICENSING (1)
7,155,000 Process, arrangement, devices for seizure of a shared telephone line 2 2002
 
Other [Check patent profile for assignment information] (5)
* 5,003,581 Telephone line priority sharing device 14 1988
* 5,014,299 Modem coupler for multi-line key telephone system 40 1989
* 5,048,073 Telephone line switching interface unit 14 1990
* 5,444,772 Telephone line lockout device 14 1994
* 5,566,233 Communication controlling apparatus for a single-line telephone with extensions thereto 32 1995
* Cited By Examiner