Lockout Patents (Class 379/184)
  • Patent number: 11393349
    Abstract: A method for air traffic control (ATC) radio communications authentication, includes receiving, by an aircraft, an ATC voice communication from an ATC facility. The method also includes receiving, by the aircraft, authentication data from the ATC facility substantially contemporaneously with the ATC voice communication. The authentication data is associated with the ATC voice communication. The method further includes authenticating the ATC voice communication using the authentication data.
    Type: Grant
    Filed: March 17, 2020
    Date of Patent: July 19, 2022
    Assignee: The Boeing Company
    Inventors: David S. Mier, Alan G. Tomaszycki
  • Patent number: 8340252
    Abstract: Disclosed herein is a method and apparatus for detecting surveillance devices on a telephone line and deployment of countermeasures therefor. The apparatus comprises a line monitoring circuit for evaluating whether the phone is off hook or ringing. A test generation circuit produces a test signal to be injected into a line and issues test commands. A signal response analysis circuit compares a test signal response to a baseline signal response and reports an anomaly when the difference between a test signal response and a baseline signal response exceeds a threshold. Additionally, an anomaly may be reported when an unusual signal is detected, such as a clock. A detection management circuit issues countermeasures to the anomaly based on programmed responses.
    Type: Grant
    Filed: June 29, 2009
    Date of Patent: December 25, 2012
    Assignee: Early Rescue Solutions, LLC
    Inventors: Hector Vasquez, Martin Kuttner
  • Patent number: 8265249
    Abstract: A computer implemented method, and apparatus for changing a state of a remote switch box. On a master switch box, a request is received from a user to set a state of the remote switch box to a selected state. A request to change the remote switch box to the selected state is transmitted from the master switch box to the remote switch box. The remote switch box connects a remote phone to a phone line. The master switch box receives a confirmation from the remote switch box of the change to the selected state. The confirmation contains the state of the remote switch box. The state of the remote switch box is displayed on the master switch box.
    Type: Grant
    Filed: July 24, 2007
    Date of Patent: September 11, 2012
    Assignee: International Business Machines Corporation
    Inventors: James Edward Bostick, Brian Wayne Hansen, John Paul Kaemmerer, Raghuraman Kalyanaraman
  • Patent number: 7509120
    Abstract: Systems and methods for processing encoded messages within a wireless communications system are disclosed. A server within the wireless communications system performs signature verification of an encoded message and provides, together with the message, an indication to the mobile device that the message has been verified. In addition, the server provides supplemental information, such as, for example, a hash of the certificate or certificate chain used to verify the message, to the device, to enable the device to perform additional checks on the certificate, such as, for example, validity checks, trust checks, strength checks, or the like.
    Type: Grant
    Filed: September 7, 2004
    Date of Patent: March 24, 2009
    Assignee: Research In Motion Limited
    Inventors: Michael K. Brown, Michael S. Brown, Herbert A. Little
  • Patent number: 7177410
    Abstract: A residential phone system allows for local control of call features from any phone extension. The phone system may include a microcontroller that communicates along the phone lines at a non-utilized frequency to several extension phones in a residence. The microcontroller permits each phone to control call features such as call waiting, conference calling, paging, or other features. A control box may be included at any or all of the extension phones to provide a convenient user interface to access the call features.
    Type: Grant
    Filed: April 19, 2005
    Date of Patent: February 13, 2007
    Assignee: Intel Corporation
    Inventors: Edward O. Clapper, Kevin P. Gambil
  • Patent number: 7023975
    Abstract: A system and method are provided for controlling communications privacy in a Home Network telephone system. The method comprises: using a gateway to send and receive calls on at least one external telephone line; supplying privacy and public mode bridging options; and, selectively excluding bridges between external telephone lines and a plurality of Home Network endpoints. In response to the privacy mode being selected, the gateway bridges a call between a first external telephone line and a first endpoint, and prevents bridges between the first external telephone line and other endpoints in the system. Alternately, when the public mode is selected, the gateway bridges a call between the first external telephone line and the first endpoint; and permits bridges between the first external telephone line and other endpoints in the system. That is, while the call is bridged to the first endpoint, a bridge is added between the first telephone line and the second endpoint.
    Type: Grant
    Filed: January 31, 2002
    Date of Patent: April 4, 2006
    Assignee: Sharp Laboratories of America, Inc.
    Inventors: Carl Mansfield, Sherman L. Gavette
  • Patent number: 6965672
    Abstract: An electronic switching system, comprising a common source of voltage to a plurality of user stations connected in parallel, an electronic means of connection to electrically connect a chosen user station to the common source of voltage, and a means of disconnection command with an optical coupler to control automatically the electronic disconnection of other user stations to the common source of voltage. A default user station is normally the chosen user station. There are means of separation of grounds for the chosen user station and the other user stations.
    Type: Grant
    Filed: March 24, 2000
    Date of Patent: November 15, 2005
    Inventor: Loubaris Mohamed Fai├žal
  • Patent number: 6882716
    Abstract: A residential phone system allows for local control of call features from any phone extension. The phone system may include a microcontroller that communicates along the phone lines at a non-utilized frequency to several extension phones in a residence. The microcontroller permits each phone to control call features such as call waiting, conference calling, paging, or other features. A control box may be included at any or all of the extension phones to provide a convenient user interface to access the call features.
    Type: Grant
    Filed: March 28, 2001
    Date of Patent: April 19, 2005
    Assignee: Intel Corporation
    Inventors: Edward O. Clapper, Kevin P. Gambil
  • Patent number: 6836540
    Abstract: In one embodiment, the present invention is directed to a method of offering a service to a user. The method comprises receiving a dialed number from a request to initiate a collect telephone call from an origination source; processing the dialed number to determine whether payment may be received for the collect telephone call, wherein the processing blocks the collect call and stores the dialed number when the processing determines that payment may not be received for the collect telephone call; and establishing a telephone connection with the dialed number to communicate an offer for the service to a user associated with the dialed number.
    Type: Grant
    Filed: July 3, 2002
    Date of Patent: December 28, 2004
    Assignee: Evercom Systems, Inc.
    Inventors: Richard Falcone, Keith S. Kelson, Jeremy W. Duke, Lee R. Johnson, Robert E. Sullivan, Randy Hoffman
  • Patent number: 6359977
    Abstract: A method and system for automatically detecting that a telephone port is being used and securing the telephone line associating with the telephone port, is presented. In one embodiment, a method and system is described for automatically securing a telephone line in a telephone system having more than one telephone lines. Usage of a device connected to the telephone line is first detected. Telephones in the system are notified via a data packet to secure the telephone line. In response to the data packet, the telephones prevent a user from accessing the telephone line.
    Type: Grant
    Filed: May 6, 1999
    Date of Patent: March 19, 2002
    Assignee: Thomson Licensing S.A.
    Inventors: Clarence C. Rudd, Linmei Shu
  • Publication number: 20020009185
    Abstract: The specification discloses a method for security control of network distant input using caller ID, which uses an ID decoder to decode and extract a caller ID from an incoming message and determine whether the caller ID exists in its database before starting a password checking step. The invention also discloses the corresponding device.
    Type: Application
    Filed: July 9, 2001
    Publication date: January 24, 2002
    Inventor: Chung-Chih Tung
  • Publication number: 20010055376
    Abstract: A device enables a user to block telephone numbers designated by a caller ID device as “Unavailable”, “Out of Area”, and “Private” numbers. And, specified numbers can be provided in a list and blocked. A user can optionally select actions for the “No Caller ID Call Block” situation. In a first setting the telephone line ring can be suppressed, caller ID data read, and a determination made whether to pass or block the call. In this first case, the block will be performed by the telephone line going off-hook momentarily and back on-hook, such that the call is answered and subsequently disconnected. In a second setting, the block will be performed by the telephone line going off-hook momentarily and back on-hook, such that the call is answered and subsequently disconnected. In a third setting, the telephone line ring will be suppressed, and the block will be performed by suppressing the ring of the telephone for the entire duration of the call attempt.
    Type: Application
    Filed: May 17, 2001
    Publication date: December 27, 2001
    Inventor: Gregg Karas
  • Patent number: 6321094
    Abstract: In a network system including a wireless mobile communications system, when establishing a connection between a wireless mobile terminal and a host computer connected to a stationary network system, the wireless mobile terminal produces a connection establishment request signal including first information which is required to obtain services from the host computer and then transmits the connection establishment request signal to the host computer. The host computer verifies the first information included in the connection establishment request signal received from the wireless mobile terminal and transmits a response signal back to the wireless mobile terminal only when the first information has been verified. This causes the connection to be established between the wireless mobile terminal and the host computer.
    Type: Grant
    Filed: January 30, 1998
    Date of Patent: November 20, 2001
    Assignee: NEC Corporation
    Inventors: Keiichi Hayashi, Hiroto Nagai
  • Patent number: 6185430
    Abstract: Voice call group functionality is provided in a satellite based air traffic control system to allow air traffic controllers and pilots of one or more aircraft to establish and maintain voice communication over a group call. A pilot of an aircraft may maintain voice communication with the same air traffic controller the entire duration of the flight over the entire globe. Voice communication between the pilot of an aircraft may be handed off from one air traffic controller to another by switching voice call groups. The voice call group functionality allows an air traffic controller to communicate simultaneously with pilots of different aircraft, and also allows pilots of different aircraft to communicate with each other.
    Type: Grant
    Filed: November 26, 1997
    Date of Patent: February 6, 2001
    Assignee: Motorola, Inc.
    Inventors: David Moon Yee, Robert Henry Bickley, Philip John Zucarelli, Theodore Woolley Keller, Jeffrey S. Osman, Randall K. Derr
  • Patent number: 6178236
    Abstract: Access is granted to a portion of a computing system, such as to a configuration menu of a telephone system. In order to grant access, a password is received from a user. A variable password is also calculated. The variable password varies with time. For example, the variable password varies with a current date and with a time of day stored by the computing system. The password received from the user is compared with the calculated variable password. When the password received from the user is equal to the calculated variable password, access is granted.
    Type: Grant
    Filed: March 27, 1996
    Date of Patent: January 23, 2001
    Assignee: Siemens Information and Communication, Networks, Inc.
    Inventors: Elie A. Jreij, Tave P. Dunn
  • Patent number: 6124879
    Abstract: A visual telephone system is disclosed which comprises a modem for transmitting and receiving video and voice signals so as to perform a visual communication via a telephone line connected therewith, a telephone hand set for a voice communication via the telephone line connected therewith, a detecting unit for detecting whether or not the telephone line is busy and generating a line state detection signal, a control unit for controlling the modem to be enabled in response to the line state detection signal and generating a switch control signal in response to a specific key entry, a switch for selectively connecting the telephone line to either the modem or the telephone hand set, and a message storage unit for storing a message so as to provide the message on a display or a speaker in response to the line state detection signal.
    Type: Grant
    Filed: July 8, 1997
    Date of Patent: September 26, 2000
    Assignee: SamSung Electronics Co., Ltd.
    Inventor: Surg-June Lee
  • Patent number: 5991386
    Abstract: In an arrangement for the connection of two or more terminals (1, 1') to one subscriber line (3) the terminals (1, 1') are connected to a chain so that the connection from the subscriber line (3) to a terminal (1) is further branched (13) to the next terminal (1'), and the arrangement according to the invention is characterized in that it comprises means (18, 20) to detect whether the terminal (1) and the next terminal (1') are in the operating state or in the idle state; a controllable switch (12, 14) for each terminal (1, 1') connected to the subscriber line (3) in order to connect the corresponding terminal (1, 1') to the subscriber line (3) and disconnect it from the line; and means (18, 20) to independently control the switch (12, 14) corresponding to each terminal (1, 1') depending on which states are detected for the terminals (1, 1'). Thus it is possible, when required, to cut off the current from the subscriber line (3) in order to disconnect the connection.
    Type: Grant
    Filed: March 13, 1997
    Date of Patent: November 23, 1999
    Assignee: Nokia Technology GmbH
    Inventor: Veikko Nurmi
  • Patent number: 5844978
    Abstract: The present invention provides for a method of restricting access to authorized users of telephone service from a telephone at a particular location which telephone is accessible by more than one individual. The present invention provides for a method of activating a telephone line by entering a valid access code and deactivating the telephone line by entering a second valid code. Calls may not generally be placed from the telephone when the telephone line deactivated. Calls made from the telephone line after the telephone line has been activated by a valid access code will be attributed to the user associated with the access code. The present invention also provides for a method of routing calls which have been designated as escape codes or priority numbers although the telephone line is in a deactivated state. The present invention also provides a method for activating the telephone line by first entering a logon code followed by an access code which is associated with a user.
    Type: Grant
    Filed: January 14, 1997
    Date of Patent: December 1, 1998
    Assignee: BellSouth Corporation
    Inventors: Ronald S. Reuss, Janine M. Irwin
  • Patent number: 5809132
    Abstract: A communication terminal device having a line voltage detection circuit 6 connected in parallel with telephone lines 2 is characterized that when either of a built in telephone set 4 or an auxiliary telephone set 5 is off-hooked and then the hook detection circuit OH1/OH2 of the that telephone set 4/5 becomes on-hooked, the true on-off-hook states of that telephone set 4/5 and the branch telephone set 3 are judged by referring to the hook detection circuit OH1/OH2 and the aforementioned line voltage detection circuit 6 after a predetermined time period T has elapsed.The communication terminal device such as a facsimile device and the like having the arrangement described above is able to detect the off-hook/on-hook state of a built in/auxiliary telephone set connected to the telephone lines in parallel with a branch telephone set without mistake even if the branch telephone set is off-hooked.
    Type: Grant
    Filed: March 7, 1996
    Date of Patent: September 15, 1998
    Assignee: Murata Kikai Kabushiki Kaisha
    Inventor: Naofumi Sakamoto
  • Patent number: 5799062
    Abstract: A system or method for interconnecting a security system with a telephone system. The system comprises one or more lockout modules that are connected between non-priority telephone devices and a telephone line. A security panel is directly connected to the telephone line. The lockout modules comprise a switch means for disconnecting the telephone device attached thereto from the telephone line when the security panel connects to the telephone line. The lockout modules further comprise a latch device that gives the first non-priority telephone device to connect to the line exclusive use of the line against other non-priority telephone devices. The lockout module further comprises a circuit that inhibits the reconnection of the telephone devices to the line to allow the security panel to recover a high and dry telephone line. The lockout module may be modified to include a switch that allows other non-priority telephone devices to share the line.
    Type: Grant
    Filed: March 7, 1997
    Date of Patent: August 25, 1998
    Assignee: Allsop, Inc.
    Inventors: Sal Lazzara, Donald C. Sorenson
  • Patent number: 5606593
    Abstract: An apparatus that after a time period settable by the user automatically returns an off-hook telephone to an on-hook condition. This apparatus thus electrically hangs up a telephone handset that is inadvertently left off-hook and allows normal handling of outgoing and incoming calls at other telephone extensions and in some embodiments, even allows calls to ring-in to the telephone having the inadvertently off-hook handset. The apparatus also senses when the inadvertently off-hook handset is returned on-hook and rapidly restores the automatic-return-to-an-on-hook condition switch to normal operation.
    Type: Grant
    Filed: November 18, 1994
    Date of Patent: February 25, 1997
    Assignee: Lucent Technologies Inc.
    Inventor: David B. Smith
  • Patent number: 5596631
    Abstract: A telephone station instrument add-on control subsystem with selectable addressing and ringing response delay techniques enhances any conventional instrument by providing added functionalities to ordinary telephone subscribers. When one or more of this enhanced station instruments are used on the same telephone line, a distributed single line PABX is formed. The formation of this system is based on the continuity of a pair of ordinary telephone wires. The specific routing of this wire pair does not affect the characteristics of the service features. A special case of this distributed system is to provide local dialed intercom services for communications among locations within an isolated area. A simplified version of this invention can be applied to improve the efficiency of data communication in a Local Area Network whose terminal information speed is comparable to the channel bandwidth of the transmission medium.
    Type: Grant
    Filed: October 5, 1994
    Date of Patent: January 21, 1997
    Inventor: Abraham Y. Chen
  • Patent number: 5592540
    Abstract: An interdiction device and method to jam or delete selected video and telephony signals. The interdiction device includes amplifiers and forward couplers to prevent the telephony signals from appearing at other undesired subscriber locations on the network.
    Type: Grant
    Filed: October 6, 1995
    Date of Patent: January 7, 1997
    Assignee: U S WEST Advanced Technologies, Inc.
    Inventor: Gregory J. Beveridge
  • Patent number: 5566233
    Abstract: In a single-line telephone, there are a plurality of extension telephone sets connected by a telephone line and each extension telephone set is connected to a communication controlling apparatus. The communication controlling apparatus includes an alternating current coupler and a power supply thus allowing two extension telephone sets to communicate with each other without being disturbed by a busy tone.
    Type: Grant
    Filed: April 21, 1995
    Date of Patent: October 15, 1996
    Inventor: Kung-hsung Liu
  • Patent number: 5563936
    Abstract: A lockout telephone comprising a keyswitch for controlling the operation of the telephone's push button keypad and speed dial buttons. The telephone can have a keyswitch with either ON and OFF positions or ON, SPEED DIAL ONLY, and OFF positions. When the keyswitch is in the ON position, the telephone is fully operational. When the keyswitch is in the SPEED DIAL ONLY position, only the speed dial buttons are operational. When the keyswitch without a SPEED DIAL ONLY position is in the OFF position, only the the keypad is inoperative. When the keyswitch with ON, SPEED DIAL ONLY, and OFF positions is in the OFF position, both the keypad and speed dial buttons are inoperative. The lockout telephone can also have an emergency dial button which is always operational, regardless of the keyswitch position.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: October 8, 1996
    Inventor: Wayne K. Washington
  • Patent number: 5559873
    Abstract: A simple and inexpensive telephone exclusion or privacy device. A conference feature is and am indicator light showing when the line is in use are also provided. The basic exclusion or privacy circuit includes only eleven components, thereby providing a very low cost device. The circuit includes a diode bridge with a Silicon Controlled Rectifier (SCR) connected across the midpoint of the bridge circuit. A resistor in series with the SCR limits the amount of current which the SCR can draw from the telephone line. A Zener diode in series with a resistor is connected between the anode and the gate of the SCR and a resistor in series with a capacitor is connected from the gate of the SCR to the second side of the bridge circuit i.e. to the point where the cathode of the SCR is connected.
    Type: Grant
    Filed: December 14, 1994
    Date of Patent: September 24, 1996
    Assignee: Notify Corporation
    Inventors: Samuel F. Wood, Gaylan I. Larson
  • Patent number: 5535261
    Abstract: A system for controlling and monitoring the recording of telephone calls in institutions such as jails and correctional facilities. Calls are recorded automatically in response to the occurrence of specific triggering events, as pre-defined under software control by a system administrator. Triggering events may include, for example, use of a specific line, attempts to use particular features (such as three-way calling), attempts to dial particular telephone numbers, or use by a particular person. Recorded calls are digitized and stored in standard MS-DOS files on either a local computer system or a remote computer across a network. Stored digitized recordings may be selected for playback under software control by a system administrator. The system of the present invention allows control of recordings from within a conventional telephone system. The integrated nature of the system provides cost savings and improved flexibility.
    Type: Grant
    Filed: August 20, 1993
    Date of Patent: July 9, 1996
    Assignee: Gateway Technologies, Inc.
    Inventors: Barry D. Brown, Paul A. J. Wakefield
  • Patent number: 5502760
    Abstract: A telephone-line dedicating apparatus which is connected between an external telephone-line and a specified telephone-line utilization apparatus such as a telephone-set, facsimile machine or the like and which upon energization causes one or more other telephone-line utilization apparatus to be unable to function connected to said external telephone-line is disclosed. Specially, when said specified telephone-line utilization apparatus is a facsimile machine, any influence on said facsimile machine which is in use, due to noises from the other equipments connected to the same external telephone-line can be prevented.
    Type: Grant
    Filed: November 10, 1994
    Date of Patent: March 26, 1996
    Assignee: General Research of Electronics, Inc.
    Inventors: Wayne Gilbert, Nobuaki Yokoyama
  • Patent number: 5483573
    Abstract: A connector unit (21) for automatically terminating a digital data services (DDS) line whenever a mating modular plug (30) is not inserted into the connector. The connector utilizes a switchable DDS jack (25) that mates with the modular plug (30) for connecting a data-transmit line and a data-receive line of a DDS network (41) to a customer's equipment (45). The connector unit has a maintenance termination circuit (40) with terminating impedances (r, r1, C and C1) and diodes (D and D1). When the plug and jack are not engaged, the maintenance termination circuit is connected to the data-transmit and data-receive lines via the normally closed jack contacts (33 and 34). As the plug and jack are engaged, the plug abuts against and, as movement continues, increasingly opens the jack contacts, causing the maintenance termination circuit to be disconnected from the customer's equipment and to be connected to the DDS network.
    Type: Grant
    Filed: June 30, 1993
    Date of Patent: January 9, 1996
    Assignees: Keptel, Inc., Bell Atlantic Network Services, Inc.
    Inventors: George R. Steenton, Michael T. Calderwood
  • Patent number: 5465297
    Abstract: The present invention is directed to a telephone line seizure circuit which may find particular application in home security systems which feature an automatic dialer which automatically sends an alarm detection signal out on a telephone line when an alarm condition is detected. The telephone line seizure unit of the present invention operates so that when the automatic alarm dialer is on-hook, the telephone line seizure units are transparent to the telephone system and the telephones can then be used normally. When the automatic alarm dialer goes off-hook, then the telephone line seizure unit operates to disconnect any telephone in use connected thereto, which will thereby allow the automatic alarm dialer to go back on-hook briefly, and after about 30 or so to go off-hook, to thereby utilize the telephone line to send out the alarm detection signal.
    Type: Grant
    Filed: March 11, 1994
    Date of Patent: November 7, 1995
    Assignee: Design Tech International Inc.
    Inventor: Khaled Azem
  • Patent number: 5444772
    Abstract: A telephone extension controller for permitting controlled access of telephone line from one of a given number of extension telephones coupled thereto when each extension telephone is controlled with the same comprising a lock-out circuit adapted to be coupled to a ring wire or a tip wire, the lock-out circuit further adapted for allowing a selected extension telephone of a plurality of extension telephones coupled to a telephone line to control and prevent the other extension telephones from accessing the telephone line when its switch hook is raised, the lock-out circuit including an optoisolator photo-coupled Darlington transistor having a conducting section and a photo-activated section and a Zener diode coupled in series with the conducting section of the Darlington transistor and coupled in parallel with the photo-activated section of the Darlington transistor.
    Type: Grant
    Filed: May 11, 1994
    Date of Patent: August 22, 1995
    Inventor: Elzie L. Coker
  • Patent number: 5414764
    Abstract: A communication unit connectable in parallel with other communication equipment to a two-wire telephone line communicates through the telephone line and a detector detects a voltage across the two-wire telephone line. A command unit commands communication by the communication unit and a controller controls the communication by the communication unit according to the detection by the detector and the command by the command unit.
    Type: Grant
    Filed: April 14, 1994
    Date of Patent: May 9, 1995
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tsunehiro Watanabe, Hisao Terajima, Teruyuki Nishii
  • Patent number: 5402482
    Abstract: A ring trip deciding method in a ring trip circuit detects voltage change in the on-hook state and the on-hook state of a terminal when the terminal such as telephone set connected to the telephone line is called.
    Type: Grant
    Filed: March 5, 1993
    Date of Patent: March 28, 1995
    Assignee: Fujitsu Limited
    Inventors: Kazuyuki Minohara, Kenji Takato
  • Patent number: 5265154
    Abstract: Apparatus for enabling or disabling a selected telephone. A control signal having a unique predetermined frequency, which corresponds to a desired state of the selected telephone, is transmitted from a transmitter through standard telephone lines. The telephone is connected to a receiver, having one of a plurality of resonant circuits each tuned to one of the unique predetermined frequencies, which receives the control signal. When the frequency of the control signal matches the tuned frequency of a resonant circuit, the receiver connects or disconnects accordingly the selected telephone from the telephone lines thereby enabling or disabling, respectively, the selected telephone.
    Type: Grant
    Filed: November 5, 1990
    Date of Patent: November 23, 1993
    Inventor: Larry Schotz
  • Patent number: 5111502
    Abstract: A telephone line bridging sensor circuit is provided which provides a variable output frequency signal to a microprocessor for measuring and storing the frequency count on a periodic basis. The circuit includes an isolation transformer to isolate the audio component of the telephone line from the sensing circuit. The loop current present in the telephone line is rectified through a full wave diode rectifier and the output of the rectifier is filtered and regulated to provide an input voltage to an astable, voltage controlled oscillator. As the current on the telephone line varies, the input voltage to the oscillator also varies a proportionate amount causing the output frequency of the oscillator to change accordingly.
    Type: Grant
    Filed: April 25, 1990
    Date of Patent: May 5, 1992
    Assignee: Command Communications, Inc.
    Inventors: William C. McClure, Bob D. Kunce, John Q. McClure
  • Patent number: 5022068
    Abstract: A branched telephone system having a plurality of telephones which are connected to a single subscriber line or to single radio apparatus functions to establish a priority set condition in which the communicating function of particular one of the telephones is validated to prevent the other telephones from being used, and further includes the function of automatically cancelling such a priority set condition.
    Type: Grant
    Filed: March 2, 1988
    Date of Patent: June 4, 1991
    Assignee: NEC Corporation
    Inventors: Hisashi Fujisaki, Keiko Shimada
  • Patent number: 4987586
    Abstract: A modem/telephone interconnect for sharing a telephone line or communication channel between a modem and a telephone or other communication device. The interconnect provides access to the telephone line by both devices but normally prevents each device from interrupting or interfering with the operation of the other. The telephone can be used to monitor data transfer by the modem without the possibility of interfering with the data signals or quiet times.
    Type: Grant
    Filed: July 31, 1987
    Date of Patent: January 22, 1991
    Assignee: Compaq Computer Corporation
    Inventors: Allen E. Gross, Marvin F. Malm
  • Patent number: 4985916
    Abstract: A telephone subscriber interface device provides privacy on a party line. The device provides for revertive calling, break-in, automatic disconnect, selective ringing, automatic number identification, and operates on the central office power supply. The device provides the following features: A connect state for the PLC in which the PLC is connected to the telephone line but in which the PLC is not responsive to other inputs, a ring decoder which detects either divided coded ringing signals or divided ringing signals in a novel manner, means for testing whether a revertive call has been properly terminated, a low power switch so that the PLC can run on telephone line power only without battery backup, and means for resetting the PLC to a ready state in the absence of other inputs.
    Type: Grant
    Filed: November 1, 1989
    Date of Patent: January 15, 1991
    Assignee: Trison Telecommunications Ltd.
    Inventors: Leo Tachuk, Michael K. Tulley
  • Patent number: 4941166
    Abstract: A voltage breakdown circuit is connected in series between telephone answering machine circuitry and a telephone line. The voltage breakdown device becomes conductive only when the voltage across its terminals exceeds a predetermined level. If a telephone connected to the same telephone line as the answering machine circuitry is placed in the off hook condition, the voltage across the voltage breakdown device falls below the threshold level and the answering machine circuitry is effectively cut off from the telephone line. The voltage breakdown circuit is also useful in defeating automatic recording equipment placed in parallel with a telephone. Such automatic recording equipment is automatically disabled whenever the voltage across the tip in ring terminals of a telephone line is above a predetermined level.
    Type: Grant
    Filed: January 4, 1988
    Date of Patent: July 10, 1990
    Inventors: Herbert H. Waldman, Kalman Drebin
  • Patent number: 4899372
    Abstract: A circuit/device that can be designed into new telephone subsets as well as connected to existing telephones to prevent unwanted telephone extensions from interfering with the controlling extension. The device is operated by a single push-button located on certain or all extensions. When operated from a certain extension, it disconnects all other extensions that are fitted with the same device until such time that either the push-button at the controlling extension is operated again or the telephone is placed "on-hook." The present device has a very simple circuit located at each extension telephone and communicates over an unused yellow wire found in standard 4-wire telephone circuits.
    Type: Grant
    Filed: January 5, 1988
    Date of Patent: February 6, 1990
    Assignee: Better Communications, Inc.
    Inventors: Ashok L. Wahi, Priya Jakatdar
  • Patent number: 4825465
    Abstract: A controller couples a modem or facsimile device to a telephone trunk or line and also connects another instrument or communications device to the same line so that the line can be shared without danger of the two devices interfering with one another. The line is divided into separate branches to connect to the two devices. Each branch has a line relay that senses line current in the tip and ring conductors of the respective branch when line current is present. A holding feature accommodates dial pulse interruptions in the line current and/or pulse signalling.
    Type: Grant
    Filed: December 10, 1987
    Date of Patent: April 25, 1989
    Assignee: Telecommunication Concepts, Inc.
    Inventor: Donald J. Ryan
  • Patent number: 4809317
    Abstract: 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.
    Type: Grant
    Filed: April 22, 1987
    Date of Patent: February 28, 1989
    Inventors: Paul R. Howe, Michael D. Morris
  • Patent number: 4807278
    Abstract: A control system has two switches for connecting a telephone device and a data device to a common telephone line. Separate circuits are provided to sense the current flowing between the telephone line and each of the devices. The circuits are coupled to the switches so that when the sensed current for one of the devices exceeds a given level, the switch for the other device is activated to disconnect the other device from the telephone line.
    Type: Grant
    Filed: May 11, 1987
    Date of Patent: February 21, 1989
    Inventor: David W. Ross
  • Patent number: 4805210
    Abstract: Automatic telephone line sharing apparatus is disclosed that will only allow one telephone set or other communication device to be connected to a shared telephone line at a time. Circuits in the apparatus sense when a first one of a plurality of telephone sets or other communication devices is connected to a shared line and causes switches to be operated disconnecting the other telephone sets and devices from the line. When the first set or device disconnects from the shared line, this is sensed and the other sets or devices are automatically reconnected to the shared line. This automatic operation insures exclusive line use by blocking line access by other telephone sets or devices sharing the common telephone line.
    Type: Grant
    Filed: September 10, 1987
    Date of Patent: February 14, 1989
    Inventor: Herbert L. Griffith, Jr.
  • Patent number: 4754274
    Abstract: The microprocessor interface device is for use in a telecomminications system including a microprocessor. The device includes a first interfacing means which receives signals from, and dispatches signals to, the telecommunications system. A second interfacing means receives signals from, and despatches signals to, the microprocessor. A memory is provided, together with arbitration means arranged to control the first and second interfacing means so that only one interfacing means at a time has access to the memory. Decoding means is adapted to respond to address signals presented to the second interfacing means by the microprocessor, to generate signals enabling areas of the telecommunications system to be accessed.
    Type: Grant
    Filed: November 27, 1985
    Date of Patent: June 28, 1988
    Assignee: Plessey Overseas Limited
    Inventor: Richard P. A. Iles
  • Patent number: 4645877
    Abstract: A party line interface for permitting the connection of a standard telephone to a telephone central office which rings selected subscribers by applying a DC ringing potential of a selected polarity to a selected one of the tip and ring lines of the party line and a ringing tone is disclosed. The interface includes a signal path having two lines with each line having an input terminal and an output terminal. The input terminals are respectively adapted to be connected to the ring and tip lines of the party line. A programmable switching means is coupled to the signal path for selectively applying the ringing signal received by the party line interface to the output terminals for application to the ringing mechanism within the standard telephone as a function of the polarity of the DC component and ground reference applied to the input terminals by the telephone company central office.
    Type: Grant
    Filed: February 28, 1986
    Date of Patent: February 24, 1987
    Assignee: Harris Corporation
    Inventor: Leonard E. Curtin