Patents Examined by Anh H. Tran
  • Patent number: 4853690
    Abstract: Monitoring a room is accomplished by measurement of air pressure where air passage resistance between a secured room and an outside atmosphere is measured and an alarm actuated, if the air passage resistance drops below a predetermined value. Evaluation of typical air pressure fluctuations in a frequency range between 0.01 Hz and 10 Hz is advantageous. The air pressure resistance may be determined by difference measurements of air pressure fluctuations in the outside atmosphere and the secured room, or as a singular process wherein a connecting tube is provided between the room to be secured and the outside atmosphere, where air movements varying as a function of air pressure fluctuations are measured. Devices for the carrying out of the process are described. The devices and the process provide a simple and cost effective alarm system that operates reliably and is secure against outwitting and sabotage.
    Type: Grant
    Filed: April 1, 1987
    Date of Patent: August 1, 1989
    Assignee: Richard Hirschmann Radiotechnisches Werk
    Inventors: Hans-Dieter Mayer, Klaus Hirrlinger
  • Patent number: 4835525
    Abstract: An apparatus for monitoring a flame which emits light, the apparatus comprising: (a) a detector for detecting the light and outputting a signal corresponding to the light; (b) a casing for enclosing the detector, the casing including an aperture for the light going to the detector; (c) a blower for supplying air to the casing; and (d) a windmill for periodically shuttering the light to the detector with a shuttering frequency, the windmill being driven by the supplied air.
    Type: Grant
    Filed: December 8, 1987
    Date of Patent: May 30, 1989
    Assignee: Kabu Shiki Kaisha Toshiba
    Inventors: Hiroshi Egi, Toshiyuki Komori
  • Patent number: 4831875
    Abstract: Fail-safe bypass monitoring system for measuring volumetric flow rates in a pipe which normally carries a relatively low pressure, low volume gas flow. The system comprises a water trap valve positioned to seal off relatively low pressure gas flow through the pipe and divert the gas flow through a flowmeter. The flowmeter receives gas flow from the pipe adjacent a first end of the water trap valve and returns gas flow to the pipe adjacent a second end of the water trap valve. The water trap valve always passes relatively high pressure gas directly through the pipe.
    Type: Grant
    Filed: May 1, 1987
    Date of Patent: May 23, 1989
    Assignee: Westinghouse Electric Corp.
    Inventor: Michael Twerdochlib
  • Patent number: 4829288
    Abstract: A magnetic marker for use with electronic article surveillance (EAS) systems in which a two-directional very high order harmonic response is obtained. The markers comprise two pairs of elongated strips of low coercive force, high permeability material positioned in a tic-tac-toe configuration such that the strips at right angles to an applied field of an EAS system collect and concentrate the lines of flux associated with the field into the strips parallel to the field, the concentrated flux being sufficient to result in a high harmonic response.
    Type: Grant
    Filed: November 30, 1987
    Date of Patent: May 9, 1989
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Clyde T. Eisenbeis
  • Patent number: 4818974
    Abstract: An electrically actuated warning system is provided for a banking institution including a plurality of teller stations and a plurality of remote bank employee stations at each of which a desk top-type work surface is provided including a name plate assembly having a front face bearing the corresponding bank employee's name facing toward the teller stations and a rearface having a plurality of silent electrically actuated visual warning signals thereon facing away from the teller stations. Each teller station includes a manually actuable switch and the warning signals at each bank employee's station include a warning signal for each of the teller stations. Actuation of each teller switch is operative to actuate the warning signal at each bank employee station.
    Type: Grant
    Filed: February 10, 1987
    Date of Patent: April 4, 1989
    Inventor: James I. Fernandez
  • Patent number: 4816818
    Abstract: A heavy duty lamp flasher for turn signals for trucks, trailers and the like including a switching relay having normally open and normally closed contacts and a moveable relay arm and relay coil, and an arc suppression circuit formed of a transistor or pair of transistors connected in parallel with the switching relay to minimize contact arcing and load carrying limitations. A diode and capacitor pair is connected to an integrated circuit oscillator for activating and deactivating the relay and another diode and capacitor pair is connected to the gate of the transistor and to the relay coil, such that the mechanical contacts of the relay, with their inherent mechanical delay, control the transistor circuitry so that the transistor provides the primary current path during movement of the arm between the normally closed and normally open contacts and the normally open contact provides the primary current path when it is closed.
    Type: Grant
    Filed: June 8, 1987
    Date of Patent: March 28, 1989
    Assignee: Truck-Lite Co., Inc.
    Inventor: Philip C. Roller
  • Patent number: 4812811
    Abstract: An alarm device, comprising a so-called alarm tag consisting of two parts arranged so as to be placeable each on one side of an article, for example an article of clothing, of fur or other article, where a needle is provided to extend from one part through the article to the second part, which alarm tag comprises devices for receiving a magnetic alternating field emitted to the alarm tag. According to the invention, the alarm tag (1) comprises devices (8,9,11,12) capable to emit an acoustic signal when the parts (2,3) of the alarm tag (1) move away from each other when the alarm tag (1) is put in a first, active, state and not to emit an acoustic signal when the parts (2,3) of the alarm tag (1) move away from each other when the alarm tag (1) is put in a second, inactive, state.
    Type: Grant
    Filed: September 25, 1987
    Date of Patent: March 14, 1989
    Assignee: Intermodulation and Safety System AB
    Inventors: Leif Asbrink, Ulf Graflind
  • Patent number: 4803473
    Abstract: A display case for receiving a transmitter module and retaining the module in place is used in a security system which detects and monitors fire, burglary, emergencies, appliance failure and the like. Transmitter modules, which are placed at each of the sensors, transmit information to a central monitor. The display case for receiving the transmitter module is designed to present the module in open view so that the user can readily discern that the transmitter is in place. The display case cover includes provision to expose the transmitter while engaging the transmitter body to hold it in place in the display case.
    Type: Grant
    Filed: January 20, 1988
    Date of Patent: February 7, 1989
    Assignee: Dicon Systems Limited
    Inventor: Stephen C. Taylor
  • Patent number: 4803467
    Abstract: A magnetic key lock provided with an alarm system, the key lock including a normally closed first switch and a normally open second switch, both switches being connected to the alarm system so that the alarm system is activated when the first and second switches are both closed. The second switch is associated with a tumbler of the lock so that the second switch is closed upon movement of the tumbler when a key or lock pick is inserted into the key slot of the lock. A magnetic sensor is provided adjacent to key slot so that a proper magnet-bearing key can activate the magnetic sensor before the second switch is closed by the tumbler movement in order to delay activation of the second switch for a selected time period to allow the proper key to open the first switch while opening the lock for inactivating the alarm system. A futher switch is provided to test the working ability of the alarm system. The alarm system can include a wirelessly controlled remote alarm.
    Type: Grant
    Filed: February 23, 1988
    Date of Patent: February 7, 1989
    Inventor: George Peters
  • Patent number: 4794378
    Abstract: A missing reminder for pocket article includes: a wallet for storing credit card or the like, a gravitational actuator clamped on the wallet and an alarming circuit which is operatively sensed when withdrawing the wallet from an owner's pocket by seating a weight disk of the actuator on a receiver to close two contacts of the alarming circuit formed on the receiver to sound the alarm and give warning to the wallet owner.
    Type: Grant
    Filed: December 23, 1987
    Date of Patent: December 27, 1988
    Inventors: Sheng-Chuan Chen, Wen-Tsung Lin
  • Patent number: 4791412
    Abstract: A surveillance system based upon generation and detection of phase shifted harmonic signals from markers on articles or persons, responsive to transmission of a reference signal at a fundamental frequency in a detection zone, may be adversely affected by the presence in the detection zone of large metal objects, such as shopping carts. Such objects can alter the phase of the harmonic signals from predetermined values. An alternate signal processing technique for such a surveillance system recognizes that immunity to such disturbances can be achieved by measuring the phase between two or more of the harmonic signals returned from the marker, because the effect of such large metal objects has been found to have the same effect on all of the harmonic signals. Correspondence to a predetermined phase difference is a reliable indicator of marker detection.
    Type: Grant
    Filed: January 28, 1988
    Date of Patent: December 13, 1988
    Assignee: Controlled Information Corporation
    Inventor: Roger Brooks
  • Patent number: 4791402
    Abstract: A signal light device mounted on the front end of an automotive vehicle and provided with a central illuminating chamber having downward diverging light passageways for projecting light rays, when actuated, forward, upward, downward and laterally for signaling to another vehicle entering the mainstream of traffic, permission to enter the mainstream of traffic, to cross in front of the signaling vehicle, or to change lanes. The signal device may also include a pair of right and left illuminating signal chambers on opposite sides of the central chamber for projecting light forward and laterally outboard to indicate permission to another vehicle to enter an intersection in front of the signaling vehicle.
    Type: Grant
    Filed: March 19, 1987
    Date of Patent: December 13, 1988
    Inventor: Ernest L. Vaughn