With Fluid-condition Responsive And/or Indicating Means Patents (Class 174/11R)
  • Patent number: 6144209
    Abstract: An elongated fluid detection cable is described for use in detecting the presence of fluid (e.g. water) in areas where fluid is not desired. The cable includes a non-conductive base and at least two conductive members (such as wires). The base is twisted about its longitudinal axis, and the two conductive members are protected from touching conductive surfaces. The cable is connected to a control system which will activate an alarm when fluid contacts the conductive members of the cable. In one system, the cable includes four conductive members.
    Type: Grant
    Filed: April 1, 1999
    Date of Patent: November 7, 2000
    Assignee: Raymond & Lae Engineering, Inc.
    Inventors: Donald A. Raymond, Donald M. Raymond
  • Patent number: 6063997
    Abstract: In a gas insulated electric apparatus having gas sections filled with insulating gas, a locating device determines a position of a gas section in which an insulation abnormality is detected, on the basis of a detection signal from sensors disposed in each of predetermined gas sections. At the same time a hindering degree diagnosing device diagnoses the degree and the kind of the insulation abnormality, by comparing a detection signal from the sensors with data stored in a data base. A valve control generates a valve control signal, responding to the locating device and the hindering degree diagnosing device, and in response to the valve control signal, a trip circuit generates a valve opening signal to open an electromagnetic valve disposed in a gas section in which an insulation abnormality is detected.
    Type: Grant
    Filed: August 15, 1994
    Date of Patent: May 16, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Fumihiro Endo, Tomoaki Utsumi, Toshio Ishikawa, Shuzo Iwaasa, Tokio Yamagiwa
  • Patent number: 5969618
    Abstract: A hose capable of carrying current to an indicator which provides external warning of imminent failure, or leak, due to wear occurring within the hose. The hose consists of an internal (primary) hose which is surrounded by an external (secondary) hose. Positioned in the annulus between the two hoses are two non-contacting electrical wires. At a point, the two electrical wires extend beyond and outside of the hoses. The protruding wires attach to a low voltage power source and to a hose failure indicator, or alarm, in series. When the internal (primary) hose fails, the fluid inside the hose escapes into the annulus between the primary and secondary hoses, making contact with the two electrical leads. This closes the circuit, thereby activating the external indicator, which may be a light or an audible signal or some other type of alarm. The external (secondary) hose is designed to withstand normal operating stress for a reasonable amount of operating hours until the hose can be replaced.
    Type: Grant
    Filed: December 19, 1996
    Date of Patent: October 19, 1999
    Inventor: Thomas Redmond
  • Patent number: 5918267
    Abstract: A system for detecting leaks from buried pipes which transport fluids other than water. The system includes a pipe for transporting the fluid, a fluid-wicking member which lies beneath the pipe, is wetted by the fluid when the fluid leaks from the pipe, and is permeable to water, and a fluid sensor which contacts the fluid-wicking member and is capable of detecting the fluid.
    Type: Grant
    Filed: June 4, 1997
    Date of Patent: June 29, 1999
    Assignee: Raychem Corporation
    Inventors: Owen Daniel Evans, Patrick K. Mumme
  • Patent number: 5661405
    Abstract: An elongate, flexible sensor for sensing an electrically conductive liquid, such as water, has two flexible electrodes extending along the sensor and two flexible sleeves extending therealong and being attached adhesively to each other along the sensor. Each electrode is a ribbon made from a carbon-filled, silicone rubber material. Each sleeve extends around an associated one of the electrodes and is braided from a filamentary, polyester material so as to define multiple apertures enabling such a liquid reaching the sensor to pass through the sleeves so as to cause a short circuit between the electrodes.
    Type: Grant
    Filed: November 6, 1995
    Date of Patent: August 26, 1997
    Inventors: Jay S. Simon, Morris Simon
  • Patent number: 5588086
    Abstract: A hermetically sealed fiber optic feedthrough module which comprises a metal or other rigid material connector feedthrough or sleeve feedthrough with a single fiber optic member or with a multitude of optical fibers extending through and protruding out of either side of the connector feedthrough or sleeve feedthrough and a pressure-blocking sealant material of polycrystalline which surrounds the fiber optic member(s) and provides a seal between the fiber optic member(s) and the inside surface of the connector or sleeve feedthrough. The feedthrough module is made by positioning the fiber optic member(s) through the connector or sleeve feedthrough and applying the polycrystalline sealant material between the fiber optic member(s) and the connector or sleeve feedthrough inside diameter to fill all voids between the fiber optic member(s) and connector or sleeve feedthrough.
    Type: Grant
    Filed: April 1, 1993
    Date of Patent: December 24, 1996
    Assignee: LiteCom, Inc.
    Inventor: Robert J. Fan
  • Patent number: 5574377
    Abstract: A device for detection of the presence of organic solvents, and a process for the fabrication of the device. This device is particularly useful as a device for the detection and localization of organic solvent leaks, and more particularly to the detection and control of liquid hydrocarbon leaks. In a preferred embodiment the device comprises the combination of a time domain reflectometer and a cable comprised of a composite material constituted of a solvent soluble or swellable thermoplastic matrix containing conductive particles in such a proportion that the whole composite becomes a conductor. Contact with the solvent to be detected causes the matrix to dissolve or swell, which brings about a change in the conductivity of the cable which can be detected by the reflectometer.
    Type: Grant
    Filed: August 10, 1994
    Date of Patent: November 12, 1996
    Inventors: Alfredo Marquez-Lucero, Pedro Fuentes-Riquelme
  • Patent number: 5410255
    Abstract: A method and apparatus for detecting and locating fluid leaks, particularly liquid leaks, and determining whether the leaking liquid being detected is a non-conductive liquid such as a hydrocarbon or a conductive liquid such as water utilizes a composite detection cable having a pair of insulated conductors and a pair of uninsulated conductors. Pulses are applied to the insulated conductors and leaks are detected and located utilizing time domain reflectometry (TDR) techniques. The resistance between the uninsulated conductors is measured to determine whether or not the leak is conductive.
    Type: Grant
    Filed: May 7, 1993
    Date of Patent: April 25, 1995
    Assignee: Perma-Pipe, Inc.
    Inventor: Douglas S. Bailey
  • Patent number: 5382908
    Abstract: Cell (19) for measuring moisture content of a material, comprising a sock (13) which is comprised of a plurality of braided threads, each thread consisting of a plurality of fibers comprised of an electrically non-conductive material. The sock is perfused with a moisture absorbing fluid. The sock comprises at least two electrodes (15, 17) in the form of wires comprised of a conducting material. These electrodes are braided as longitudinal threads in the sock (13). The electrodes are spaced from each other and extend essentially parallel to each other, the sock (13) being braided around a cylindrical core (11) comprised of an electrically non-conducting material. The axis of the core is essentially parallel to the electrodes (15, 17) and the threads in the sock (13) are permanently under tension to achieve contact between the threads and the electrodes (15, 17).
    Type: Grant
    Filed: September 11, 1991
    Date of Patent: January 17, 1995
    Assignee: Bo Gosta Forsstrom
    Inventors: Bo G. Forsstrom, Per E. Wikefeldt, Leif A. Unruh
  • Patent number: 5382909
    Abstract: Detection of liquid leaks and other changes in variables is disclosed. The event causes two elongate conductors to become electrically connected at a location which is determined by the event, thus creating a system in which the connection point can be located by measuring the potential drop from one end of one of the conductors (called the locating member) to the connection point. The system comprises a balancing component so that its sensitivity is not dependent on the location of the event along an elongate path. A fixed current flows through the connection, so that the result is independent of the resistance of the connection. The locating member can be a continuous resistive wire, coated with a conductive polymer; such a locating member can form part of a sensor cable in which the elongate components of the circuit are in a wrapped configuration. Alternatively the locating member comprises a plurality of discrete resistors.
    Type: Grant
    Filed: July 30, 1993
    Date of Patent: January 17, 1995
    Assignee: Raychem Corporation
    Inventors: Michael Masia, James P. Reed, Robert S. Wasley, Larry R. Reeder, Peter L. Brooks, Thomas W. Tolles, Louis M. Frank, Mauro Bonomi, Ray F. Stewart, John Lahlough, Laurence Welsh
  • Patent number: 5378995
    Abstract: A low molecular weight organic liquid detection sensor which is a wire body formed by coating a core material with a conductive layer made of a substantially non-crosslinked material having a Shore A hardness not more than 70 which is mainly composed of thermoplastic elastomer and conductive carbon, the conductive layer varying in its electric resistance upon contact with a low molecular weight organic liquid. The sensor of the invention permits secured mechanical strength, its easy installation in a narrow conduit or over a wide area, and highly sensitive sensing of a low molecular weight organic liquid in the longitudinal direction.
    Type: Grant
    Filed: March 2, 1993
    Date of Patent: January 3, 1995
    Assignee: Mitsubishi Cable Industries, Ltd.
    Inventors: Toshio Kudo, Masaaki Nagai, Yasuo Shiraiwa
  • Patent number: 5341128
    Abstract: A sensor for detecting the presence of hydrocarbons and hydrocarbon containing fluids. It is formed of a first conductor which is formed of a metal wire or metal foil covered by an insulative sheath; a second conductor which consists of a hydrocarbon swellable elastomer and one or more conductive fillers; optionally an abuse/abrasion resistant jacket overlaying and preferably surrounding the two conductors and optionally a hydrocarbon permeable overcoat overlaying the jacket. The sensor may be in the form of a continuous length wire or a tape or a sheet. It may be coupled to an electric supply at one portion and a resistance indicator at the return portion. The resistance indicator is then attached to a signaling device such as a light or alarm.
    Type: Grant
    Filed: April 10, 1992
    Date of Patent: August 23, 1994
    Assignee: Chomerics, Inc.
    Inventors: Paul Keyser, George Watchko
  • Patent number: 5319155
    Abstract: The duct comprises an inner tube in which the wires are disposed, and this inner duct is placed inside an outer tube so as to provide a continuous inner space between the tubes, which completely surrounds the inner tube. A water inlet is in communication with the inner space and water is allowed to penetrate into the inner space upon the opening of a valve. The valve is operated by a fire detector. Upon activation of the valve in case of fire, water circulates through the inner space and is rejected into a drain. This system constitutes a fire and heat barrier for the wires of a building, for example.
    Type: Grant
    Filed: September 2, 1992
    Date of Patent: June 7, 1994
    Assignee: Ramfiq Fireproof Systems Inc.
    Inventor: Jules Maroist
  • Patent number: 5313823
    Abstract: A leak detection cable for detecting aqueous based liquids that contain a surfactant is composed of an insulated wire conductor (1 and 2) wrapped with a water resistant yarn (3) and a braided second conductor (4).
    Type: Grant
    Filed: March 10, 1993
    Date of Patent: May 24, 1994
    Assignee: W. L. Gore & Associates, Inc.
    Inventors: Samuel Berkman, Jack A. Sahakian
  • Patent number: 5256976
    Abstract: A power apparatus has a network formed by a plurality of interconnected components being, e.g., one or more high voltage conductors in a casing of a metal filled with an insulating gas. Detectors are provided which detect electromagnetic waves, which are generated if there is a fault. The electromagnetic waves are analyzed to detect the location of the fault. The analysis may make use of attenuation coefficients corresponding to each component of the network to extrapolate between detectors on either side of the fault and/or to compare with predetermined wave strengths. A map of the network may be stored in a suitable memory to assist in the calculation of the fault location, and the memory may also store the attenuation coefficients themselves. The location of the fault may then be displayed by a suitable display, to give the time variation of the fault.
    Type: Grant
    Filed: March 1, 1991
    Date of Patent: October 26, 1993
    Assignee: Hitachi, Ltd.
    Inventors: Toshio Ishikawa, Fumihiro Endo, Shuzo Iwaasa, Tomoaki Utsumi, Tokio Yamagiwa, Yoshinori Tagawa
  • Patent number: 5235286
    Abstract: An elongate sensor for detecting and locating presence of a liquid, e.g. water or a hydrocarbon. The sensor includes first and second elongate members which are spaced apart from each other and each of which is a metal conductor covered by a conductive polymer; a third, insulated elongate conductor; and an elongate insulating core. At least one of the elongate members is helically wrapped around the core. Presence of the liquid at any point along the length of the sensor causes the first and second members to be electrically connected at that point, creating a system in which the potential drop down one of the members can be measured and the location of the connection determined.
    Type: Grant
    Filed: May 9, 1991
    Date of Patent: August 10, 1993
    Assignee: Raychem Corporation
    Inventors: Michael Masia, James P. Reed, Robert S. Wasley, Larry R. Reeder, Peter L. Brooks, Thomas W. Tolles, Louis M. Frank, Mauro Bonomi, Ray F. Stewart, John Lahlough, Lawrence Welsh
  • Patent number: 5191991
    Abstract: A fastening which allows a bolted-on cap to part from a body when excessive pressures develop in a cavity in the body, comprises a nut and bolt arrangement, and includes a weakened tubular spacer surrounding each bolt, between the bolt head and the cap. The wall of the spacer is drilled or scored in its mid-length area. The material and proportions of the spacer, and the proportions of the score or drilling, are so matched in relation to a particular pressure environment, that on excessive pressure developing, the load exerted on the cap causes the spacer to collapse in controlled manner, rather than merely crushing or breaking.
    Type: Grant
    Filed: May 28, 1991
    Date of Patent: March 9, 1993
    Assignee: Northern Engineering Industries PLC
    Inventor: Leonard Jackson
  • Patent number: 5190069
    Abstract: A leak detection apparatus is shown for monitoring leakage from household water systems. Upon detection of a leak, the water supply valve is automatically shut off. A pair of spaced apart wires are imbedded in an insulating tape with liquid cell sensor elements formed at spaced intervals about uninsulated sections of the wires. The tape is placed about the pipe to be monitored so as to collect the leaking water within the liquid cell sensor elements to electrically connect the conductors within a cell. Electronic circuitry actuates a servo to turn off a supply valve and/or sound an alarm. The water collecting elements eliminate unintended alarms due to condensation.
    Type: Grant
    Filed: April 27, 1992
    Date of Patent: March 2, 1993
    Inventor: Raymond C. Richards
  • Patent number: 5172730
    Abstract: An elongated fluid detection device, together with a body of absorbent material, is located between the inner surface of a pipe and an impervious liner spaced from the inner surface thereof, the detection device being operatively connected to an external station. The impervious layer may be of a type normally used for relining defective pipes in situ, and the body of absorbent material, together with the fluid detecting element, preferably substantially filling the cylindrical space between the inner surface of the pipe and the impervious liner.
    Type: Grant
    Filed: February 7, 1992
    Date of Patent: December 22, 1992
    Assignee: Insituform of North American, Inc.
    Inventor: F. Thomas Driver
  • Patent number: 5159276
    Abstract: A leak detection system and method are disclosed. The capacitance of a leak detection cable is changed by a leaking liquid. A capacitance measuring circuit detects changes in the capacitance of the cable and thereby detects the presence of a leak. The capacitance measuring circuit includes an inverter, a current source, a comparator, and a timer. The inverter inverts a DC voltage to produce a mirror-image invented DC voltage. The current source produces a constant current proportional to the mirror image inverted DC voltage and supplies the constant current to the cable such that the cable is charged. A comparator compares the voltage across the cable to the input voltage and produces a match signal when they are equal. A timer which is responsive to the match signal measures the time required for the cable to be charged. The capacitance of the cable is directly proportional to the charge time.
    Type: Grant
    Filed: July 8, 1991
    Date of Patent: October 27, 1992
    Assignee: W. L. Gore & Associates, Inc.
    Inventor: William J. Reddy, III
  • Patent number: 5146105
    Abstract: An internal pressure explosion-proof system by which an electric motor or the like is not rendered operative until after gas in an airtight vessel is replaced with certainty by protective gas. The internal pressure explosion-proof system includes a gas flow detector provided in an exhaust pipe for detecting an amount of protective gas exhausted from an airtight vessel in which an electric appliance which may produce a spark or fire is accommodated, and a controller for enabling operation of the electric appliance when a flow amount detected by the gas flow rate detector when protective gas is fed into the airtight vessel reaches a predetermined level and the internal pressure of the airtight vessel exceeds another predetermined level.
    Type: Grant
    Filed: September 27, 1990
    Date of Patent: September 8, 1992
    Assignee: Kabushiki Kaisha Kobe Seiko Sho
    Inventors: Mitsuyoshi Obata, Noboru Takagi
  • Patent number: 5140847
    Abstract: A cable for detecting location of liquids comprises a core element sensitive to pulling or bending, a first sheathing of a material which swells in the liquid to be detected, and a sheathing affixed to the first sheathing and comprising a dense plaiting of high-stability yarn with low longitudinal expansion, and having a plaiting angle which is greater or smaller than the so-called neutral angle.
    Type: Grant
    Filed: December 10, 1990
    Date of Patent: August 25, 1992
    Assignee: Kabelwerke Reinshagen GmbH
    Inventors: Norbert Tausch, Wolfgang Diegmann
  • Patent number: 5109202
    Abstract: A structure for connecting metal conductors in an oil-leak detector having the conductors covered with porous polytetrafluoroethylene (PTFE) and the metal conductors connected by a band of carbon-filled porous PTFE. The conductors, the porous polytetrafluoroethylene and the band of porous polytetrafluoroethylene surrounded by a hydrocarbon-penetrable jacket.
    Type: Grant
    Filed: July 20, 1989
    Date of Patent: April 28, 1992
    Inventor: Juji Akiba
  • Patent number: 5084679
    Abstract: A detector for use in a detecting device determines the occurrence of a change in the conductivity of a medium includes electrical conductors. The respective electrically insulated conductors are prepared at predetermined, restricted locations thereon in order to expose parts of the conductor material. The electrical conductors are provided as two or more twined or twisted conductors which are electrically insulated from one another. The electrically insulated layer is removed from the outermost parts of the conductors with the aid of a mechanical working process.
    Type: Grant
    Filed: November 28, 1990
    Date of Patent: January 28, 1992
    Inventor: Stig T. H. Lofgren
  • Patent number: 5017908
    Abstract: A signal-carrying member responsive to the presence of a solvent and suitable for use in a security cable or a liquid leakage detector, comprises a conductive ink 20, consisting of a particulate conductive material and a non-conductive carrier medium, printed on to a non-conductive strip 17 and conductors 16 such that when the printed material is contacted by a solvent to which the carrier medium is sensitive, conductive material will be released from the printed material and can be used to vary a signal passed through the signal-carrying member.
    Type: Grant
    Filed: March 28, 1990
    Date of Patent: May 21, 1991
    Inventor: Hugh Macpherson
  • Patent number: 5015958
    Abstract: Detection of events, e.g. liquid leaks and other changes in varibles. The event causes two conductors to become electrically connected, and thus creating a system in which the connection point can be located by measuring the potential drop from one end of one of the conductors (called the locating member) to the connection point. Preferably a fixed current flows through the connection, so that the result is independent of the resistance of the connection. The locating member can be a continuous resistive wire, preferably coated with a conductive polymer; such a locating member can form part of a sensor cable in which the elongate components of the circuit are in a wrapped configuration, or part of a cable in which the conductors are separated by a member shaped to prevent capillary action of a liquid from connecting the conductors. Alternatively the locating member comprises a plurality of discrete resistors.
    Type: Grant
    Filed: June 27, 1989
    Date of Patent: May 14, 1991
    Assignee: Raychem Corporation
    Inventors: Michael Masia, James P. Reed, Robert S. Wasley, Paul D. Hauptly, Larry R. Reeder, Peter L. Brooks, Thomas W. Tolles, Louis M. Frank, Mauro Bonomi, Denis Wales, Ray F. Stewart, John Lahlouh, Laurence Welsh
  • Patent number: 4972179
    Abstract: Liquid leakage detection apparatus is provided comprising: (a) a long detecting component wherein there are the following components bundled together: (i) a first conductor having a leading end and a trailing end, the first conductor covered by insulation, (ii) a second bare conductor having a leading end and a trailing end, the second conductor positioned parallel to the first conductor, the trailing end of the second conductor being connected with the trailing end of the first conductor, and (iii) a third conductor covered by a porous insulation and positioned parallel to the second conductor, (b) the leading end of the first conductor and the leading end of the second conductor being connected by the detecting means which detects and indicates a potential difference between the first and second conductors; (c) the leading ends of the first and second conductors also being connected, respectively, to one of the electrodes of a power supply, each through respective, known resistances; and (d) the third condu
    Type: Grant
    Filed: July 26, 1989
    Date of Patent: November 20, 1990
    Assignee: Junkosha Co., Ltd.
    Inventor: Juji Akiba
  • Patent number: 4963693
    Abstract: A protective or purge enclosure provides a positive atmosphere around an operating device such as a hand-held computer or calculator contained therein. The protective enclosure has sufficient flexibility, even though providing a positive, sealed atmosphere, to enable the user to operate the functional features of the device sealed within the enclosure, and the material forming the device is sufficiently transparent to enable the user to view the functional features of the device for operation. A visible indicator provided on the enclosure enables the user to determine if the enclosure is maintaining the positive atmosphere sealed therein.
    Type: Grant
    Filed: September 1, 1989
    Date of Patent: October 16, 1990
    Assignee: Ampex Corporation
    Inventor: David A. Kodl
  • Patent number: 4931741
    Abstract: A detection and location system, e.g. for liquid leaks, comprising a trunk line sensor cable and a plurality of branch line cables at intermediate points of the trunk cable. Each of the cables comprises two insulated conductors and two non-insulated conductors, e.g. conductive polymer-coated wires, which become connected upon occurrence of a leak. In one embodiment, each of the insulated conductors in the trunk line is continuous and each of the non-insulated conductors is discontinuous at each intermediate point; the branch line conductors are respectively connected to the discontinuous ends of the non-insulated trunk line conductors, and are connected in pairs of one insulated and one non-insulated conductor at the end of each branch.
    Type: Grant
    Filed: December 20, 1988
    Date of Patent: June 5, 1990
    Assignee: Raychem Corporation
    Inventors: Heinrich Koppitsch, Francis Sparling
  • Patent number: 4926129
    Abstract: A sensing assembly suitable for detecting both a first event which involves the presence of an electrolyte and a second event which does not involve the presence of an electrolyte, and for distinguishing between them. The assembly comprises a first conductor and a second conductor which is electrically insulated from the first conductor in the absence of both first and second events but becomes electrically connected to the first conductor by either an ionic connection in the presence of a first event or an electronic connection in the presence of a second event. The assembly also comprises a sensing apparatus of determining whether the connection is ionic or electronic. The assembly is useful for detecting leaks of hydrocarbons, e.g. gasoline, and water in storage tanks.
    Type: Grant
    Filed: October 12, 1988
    Date of Patent: May 15, 1990
    Assignee: Raychem Corporation
    Inventors: Robert S. Wasley, James C. Holmes
  • Patent number: 4918977
    Abstract: The present invention relates to a liquid leakage detector line for detecting the leakage, if occurs, of a liquid such as sulfuric acid or strong alkali from a transportion pipe line or a storage tank. The liquid leakage detector line comprises: a pair of wiry electrodes each including a conductor covered with an insulator layer made of macromolecular material including an ester bond, the wiry electrodes being disposed substantially in parallel with each other; and a liquid-absorbent material covering these wiry electrodes. The liquid-absorbent material may be a braided body layer made of liquid-absorbent yarn which is disposed outside of the pair of wiry electrodes, or may be a braided body layer similar to the first-mentioned braided body layer which is disposed at the outer periphery of each of the wiry electrodes. If a sulfuric acid or alkali liquid leaks, the liquid-absorbent material covering the wiry electrodes absorbs such leakage liquid.
    Type: Grant
    Filed: September 30, 1987
    Date of Patent: April 24, 1990
    Assignee: Tatsuta Electric Wire and Cable Co., Ltd.
    Inventors: Yasuhiko Takahashi, Kunimitsu Tamura, Nagato Niimura, Keizo Asao, Teruyosi Honoki, Tadaaki Masui, Masuo Ishizaka
  • Patent number: 4910998
    Abstract: A fluid detection system includes a cable which is capable of being dried easily after coming into contact with the fluid being detected and displays a measurable change in characteristic impedance immediately upon contact with the fluid. The cable comprises an inner conductor and a cylindrical outer conductor disposed in a substantially parallel and coaxial relationship with each other with a dielectric detection layer coaxially disposed between the inner and outer conductors. The outer conductor is of an open braided construction which permits easy passage therethrough of the fluid to be detected. The detection layer comprises a pair of solid dielectric elements stranded around the inner conductor in a double helical configuration and defining an air gap between the two conductors which is adapted to retain the fluid so as to measurably change the characteristic impedance of the cable.
    Type: Grant
    Filed: May 1, 1987
    Date of Patent: March 27, 1990
    Assignee: Andrew Corporation
    Inventors: Frank R. Willis, Sitaram Rampalli, Vijay K. Chopra, Robert D. Perelman
  • Patent number: 4896527
    Abstract: A solvent leak detecting sensor is provided comprising: (a) a first electrical conductor and a second electrical conductor installed on an electrically insulating substrate in the form of a detection circuit network, the conductors being exposed and separated from each other, (b) the exposed portions of the first conductor and second conductor being covered by a layer of an electrically insulating material which is both water-repellent and which is dissolvable by the solvent that is to be detected, and (c) a top layer covering the layer in "b", this top layer being both porous and electrically conductive. The layer which is both water-repellent and which is dissolvable by the solvent that is to be detected is preferably polyvinylchloride, and the top layer is preferably conductive carbon powder.
    Type: Grant
    Filed: July 14, 1989
    Date of Patent: January 30, 1990
    Assignee: Junkosha Co., Ltd.
    Inventor: Juji Akiba
  • Patent number: 4877923
    Abstract: A sensor cable for detecting and locating liquid chemicals, especially hydrocarbons, and/or water leaks without interruption of the system, wherein two or three conductors and appropriate insulation are arranged in a configuration that provides circuits for detecting and locating liquid chemicals and for detecting and locating liquid water.
    Type: Grant
    Filed: August 17, 1988
    Date of Patent: October 31, 1989
    Assignee: W. L. Gore & Associates, Inc.
    Inventor: Jack A. Sahakian
  • Patent number: 4862088
    Abstract: Remote sensing of conditions in telecommunications splice case, such as pressure or humidity. The splice case may contain a transducer which alters a resonant frequency of a circuit associated with the splice case.
    Type: Grant
    Filed: October 4, 1985
    Date of Patent: August 29, 1989
    Assignee: Raychem Corporation
    Inventors: Nolf J. Etienne, Atkinson E. Browell
  • Patent number: 4862146
    Abstract: An apparatus for detecting the occurrence of an event, e.g. the presence of a liquid leak. The apparatus includes an elongate flexible core consisting of elongate elements which are twisted together. The elongate elements comprise first and second sensing members, which each have an electrically conductive outer surface and are physically separated from one another, and at least two elongate insulating members. These elongate elements are covered by a flexible braid which exerts a compressive force on the core. In one aspect of the invention, the flexible braid undergoes a reversible change in appearance when exposed to electrolyte, indicating the location of a leak.
    Type: Grant
    Filed: March 27, 1987
    Date of Patent: August 29, 1989
    Assignee: Raychem Corporation
    Inventors: Kenneth McCoy, Neil Edwards, Robert Wasley, Denis Wales
  • Patent number: 4850672
    Abstract: A strain compensated fiber optic cable composed of a hollow central member made from an elastic material capable of being physically enlarged, such enlargement capable of being at least partially reversed upon demand; and, a plurality of optical fibers having a first pitch diameter disposed, either in the sidewall of the central member, or on the outermost surface of the central member, so that upon enlargement of the central member, the first pitch diameter of the optical fiber can be changed to a second pitch diameter and upon reversal of the enlargement, the second pitch diameter can be changed to either the first pitch diameter or another pitch diameter.
    Type: Grant
    Filed: February 19, 1988
    Date of Patent: July 25, 1989
    Assignee: Siecor Corporation
    Inventor: Bernd D. Zimmermann
  • Patent number: 4843327
    Abstract: A detection and location system, e.g. liquid leaks, comprising a trunk line sensor cable and at least one branch line cable; each of the cables comprise two insulated conductors and two non-insulated conductors which are not connected to each other in the absence of a leak but which become connected upon occurrence of a leak. In the trunk line cable, the insulated conductors form part of a circuit which enables the location of a leak to be detected. In the branch line, one of the insulated conductors and one of the non-insulated conductors are connected so as to form a loop connecting the ends of the non-insulated conductors of the branch cable.
    Type: Grant
    Filed: June 3, 1987
    Date of Patent: June 27, 1989
    Assignee: Raychem Corporation
    Inventors: Heinrich Koppitsch, Francis C. Sparling
  • Patent number: 4843305
    Abstract: A liquid leakage sensor having spaced apart pairs of insulated conductors on oppositge sides of a strip of insulation and aperture access from one side of the strip to conductors on the other side. Can be wrapped about small pipes or objects without conductor breakthrough of insulation and electrical contact with pipe.
    Type: Grant
    Filed: September 2, 1988
    Date of Patent: June 27, 1989
    Assignee: W. L. Gore & Associates, Inc.
    Inventor: Juji Akiba
  • Patent number: 4843187
    Abstract: A gasket assembly including a base having a central opening and a circular slot having an undercut portion extending around the central opening, a circular gasket positioned in the circular slot and having a tapered side located proximate the undercut portion, and cementitious sealant material abutting the tapered side of the gasket and in the undercut portion for retaining the gasket in the slot. The gasket assembly is especially useful for the seal for the pressure relief valve of an electrical power transformer.
    Type: Grant
    Filed: February 5, 1988
    Date of Patent: June 27, 1989
    Assignee: Qualitrol Corporation
    Inventor: Wendell D. Johnson
  • Patent number: 4819250
    Abstract: Apparatus for measuring temperature at a hot point along an energy transmission cable (1) when the temperature exceeds a fixed limit temperature, the apparatus comprising a tube (3) containing a liquid which is vaporizable in the vicinity of said limit temperature and which is disposed in the energy transmission cable or in contact with its periphery, together with means for detecting an increase in the vapor pressure of said liquid at least one point along said tube, the apparatus being characterized in that said tube is connected at one of its ends to means for detecting an increase in the pressure exerted by the liquid at said end.
    Type: Grant
    Filed: October 21, 1987
    Date of Patent: April 4, 1989
    Assignee: Les Cables de Lyon
    Inventor: Henri Thevenon
  • Patent number: 4769513
    Abstract: There is disclosed a cable closure which includes a central closure body and a pair of end caps preferably made from structural foam situated at each end of the closure body. There is also disclosed a cable block which includes void filling material selectively inserted among the insulated conductors of the cable and a directional control device which consists of a conduit also selectively inserted among the insulated conductors of the cable. Together the cable closure, cable block and directional control device make up the splice closure system. There may also be provided a heat recoverable seal adhesively attached to the cable closure in which case there will also be provided means for preventing milk-off of the seal from the cable closure. finally, there is disclosed a method for forming the cable block.
    Type: Grant
    Filed: July 9, 1987
    Date of Patent: September 6, 1988
    Assignee: Raychem Corporation
    Inventors: Glen W. Ragland, Bobby Simonton, Phillip J. Snoke, Kenneth D. Timmerman, Christian A. M. Debbaut, Keith Dawes, Whit G. Halstead, Lowell Koht
  • Patent number: 4764232
    Abstract: A closure and method for protecting a splice connecting at least two cables. The closure includes a flexible reservoir positioned around the splice, a curable liquid sealant introduced into the reservoir, a means applied to the reservoir for increasing the pressure therein and a pressure measuring tube communicating between the inside and outside of the reservoir.
    Type: Grant
    Filed: September 26, 1986
    Date of Patent: August 16, 1988
    Assignee: Raychem Corporation
    Inventor: Thomas A. Hunter
  • Patent number: 4746911
    Abstract: This invention relates to an alarm device for isolated pipe systems.
    Type: Grant
    Filed: July 9, 1987
    Date of Patent: May 24, 1988
    Assignee: Rune Helmersson
    Inventor: Allan Laine
  • Patent number: 4739254
    Abstract: The low voltage capacitor of a capacitive divider of a metalclad substation is located in a sealed compartment separated from the substation enclosure. In normal operation, the compartment is in direct communication with the enclosure via a communication orifice. The compartment can be isolated from the enclosure by closing the communication orifice valve to drain this compartment and thus have access to the low voltage capacitor or to other components of the capacitive divider housed in this compartment. Any pressure or temperature difference between the compartment and the enclosure, liable to affect the measurement, is thus avoided, while authorizing access to the low voltage capacitor without having to drain the installation.
    Type: Grant
    Filed: October 8, 1986
    Date of Patent: April 19, 1988
    Assignee: Merlin Gerin
    Inventors: Georges Henry, Robert Girard, Jean Kieffer
  • Patent number: 4698456
    Abstract: A pressurizable housing for an electrical apparatus which can be used in an explosive environment has a cable feedthrough connected to an electrical unit within the housing. The cable feedthrough also accommodates a passage for pressurizing the interior of the housing with a gas excluding the incursion of explosive gases into the housing.
    Type: Grant
    Filed: October 3, 1985
    Date of Patent: October 6, 1987
    Inventor: Martin Hamacher
  • Patent number: 4689439
    Abstract: A superconducting-coil apparatus according to the present invention comprises a normal-fluid helium bath, a superfluid helium bath, a channel connecting the two baths, superconducting coils contained in the superfluid helium bath, current lead wires extending from an exciting current source to the superconducting coils, through the channel, and a valve plug normally closing the channel and adapted to open the channel when the pressure inside the superfluid helium bath rises above a predetermined level. If the superconducting coils undergo quenching while they are being excited, the superfluid helium is gasified by Joule heat, produced in the coils. As a result, the pressure inside the superfluid helium bath increases, so that the valve plug is urged to open the channel due to the pressure difference. The gasified helium directly cools those portions of the lead wires which pass through the channel, thus these wire portions are prevented from being burned out.
    Type: Grant
    Filed: September 25, 1986
    Date of Patent: August 25, 1987
    Assignee: Kabushiki Kasiha Toshiba
    Inventor: Akio Sato
  • Patent number: 4677371
    Abstract: A coaxial cable and a bare wire are aligned in parallel relationship and affixed within insulation covers which have openings therein so as to partly expose both the bare wire and the outer conductor of the coaxial cable at the atmosphere, forming a leak detecting sensor. By the use of resistance meters, the core wire of the coaxial cable is utilized to detect both the presence and the location of a leak.
    Type: Grant
    Filed: September 6, 1985
    Date of Patent: June 30, 1987
    Assignee: Junkosha Co., Ltd.
    Inventor: Haruo Imaizumi
  • Patent number: 4676266
    Abstract: An improvement in a pressure relief device of the type used in a power transformer, the improvement consisting of a flat circular gasket fixedly mounted about its inner periphery, and having its outer periphery flexibly arranged for wiping contact with the inner surface of a cup-like valve member.
    Type: Grant
    Filed: January 7, 1982
    Date of Patent: June 30, 1987
    Assignee: Qualitrol Corporation
    Inventor: Wendell D. Johnson
  • Patent number: 4609900
    Abstract: In a high-voltager transformer including a closed casing, a magnetic core with at least one winding, a cooling liquid filling the casing and surrounding the winding, and insulated casing lead-throughs for connecting external lines to the winding, a compensating device forms part of the casing and is exposed to the cooling liquid for permitting expansion of the cooling liquid on being heated, and the cooling liquid is subjected to a pressure greater than that of the ambient air at all operating temperatures of the transformer.
    Type: Grant
    Filed: June 17, 1985
    Date of Patent: September 2, 1986
    Inventors: Bruno Bachhofer, Anton Locher