Cordless telephone

Patent 4640987 Issued on February 3, 1987. Estimated Expiration Date:

April 19, 2005. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

Transceiver having interphone system
Patent #: 4392243
Issued on: 07/05/1983
Inventor: Ohhashi , et al.

Wireless telephone system with intercom signalling and auxiliary station
Patent #: 4468539
Issued on: 08/28/1984
Inventor: Schober

Wireless telephone system with combination filter/oscillator circuit
Patent #: 4468540
Issued on: 08/28/1984
Inventor: Cripps

Wireless telephone system with high level dial pulse signalling
Patent #: 4469918
Issued on: 09/04/1984
Inventor: Cripps

Wireless telephone extension unit with high level dial pulse signalling Patent #: 4471166
Issued on: 09/11/1984
Inventor: Cripps

Inventors

Application

No. 06/725341 filed on 04/19/1985

US Classes:

455/462, Including private cordless extension system379/159, With intercom system455/410, Security or fraud prevention455/414.1, Special service455/417Call diversion

Examiners

Primary: Lev, Robert

Attorney, Agent or Firm

International Classes

H04M 1/72 (20060101)
H04M 1/725 (20060101)

Foreign Application Priority Data

1984-04-23 JP

Abstract

A cordless telephone has a transfer capability by which an incoming telephone call may be transferred from the base unit to the handset unit or from the handset unit to the base unit. Each unit includes an intercom key which may be actuated to place the telephone in an intercom mode wherein the base unit and the handset unit are in communication with each other while the incoming call is on hold. Deactuation of one unit in the intercom mode results in the other unit being automatically adapted to receive the incoming call. Alternatively, actuation of either intercom during the intercom mode results in both units being automatically adapted to receive the incoming call and placed in communication with each other.