Immersible Electrode Type Patents (Class 73/304R)
  • Patent number: 5626053
    Abstract: A floatless liquid level gauge assembly utilizing polymeric resistive/conductive elements is provided which measures the liquid level of partially conductive or conductive liquids in a tank using a three terminal voltage divider network or a two terminal voltage or current network. The polymeric resistive/conductive element(s) extending into the tank and the liquid in the tank provide an electrical path which provides a signal proportional to the liquid level in the tank.
    Type: Grant
    Filed: May 16, 1996
    Date of Patent: May 6, 1997
    Assignee: Rochester Gauges, Inc.
    Inventor: Cecil M. Williamson
  • Patent number: 5627523
    Abstract: A liquid level sensor device, particularly adapted for use with corrosive and hazardous liquids such as oil, for measuring the liquid level in a storage tank or vessel. A tubular device is placed vertically in a liquid storage tank and senses the liquid level by having a float embedded with magnets move vertically along the axis of reed switches encased in the tubular device. The device contains temperature sensors to measure the temperature of the tank fluid, and microprocessors that scan the reed switches, transmitting data through a connector in the device top to a nearby computer for recording and transmission to a control and monitoring location. The electrical data system inside the device utilizes only two conductive trace runs throughout the device length to maximize reliability while minimizing the copper used. Special mechanical and electrical assembly connectors inside the device permit the device to flex safely in turbulent liquid conditions, without breakage.
    Type: Grant
    Filed: June 3, 1996
    Date of Patent: May 6, 1997
    Assignee: Power Paragon Inc.
    Inventors: Leonid R. Besprozvanny, Alan R. Ball
  • Patent number: 5625343
    Abstract: In devices for determining and/or monitoring a predetermined level with a sensor that is excited to perform mechanical oscillations at its self-resonant frequency by means of an electronic excitation circuit which is excited via a piezoelectric excitation and a reception transducer and an evaluation circuit for triggering display and/or switching processes, there exists the difficulty that the natural frequencies of the sensors are different due to the manufacturing conditions, and that the operating frequency must be adjusted individually for each sensor. This disadvantage makes repair and maintenance procedures quite difficult.
    Type: Grant
    Filed: June 1, 1994
    Date of Patent: April 29, 1997
    Assignee: Endress + Hauser GmbH + Co.
    Inventor: Werner Rottmar
  • Patent number: 5621400
    Abstract: A method an apparatus for detecting icing on an aircraft particularly flight surfaces by using the electrical insulating properties of ice on a conductive wing surface utilizing a simple conductive current device engageable selectively on the suspect flight surfaces.
    Type: Grant
    Filed: September 7, 1995
    Date of Patent: April 15, 1997
    Inventor: Ronald W. Corbi
  • Patent number: 5605656
    Abstract: A liquid filling method and in particular a lens material liquid filling method suitable for manufacturing a plastic lens. A thermal sensing portion (2a) of a temperature sensor (2) is set and kept to a temperature different from that of a liquid (3). The liquid (3) is poured into a vessel (8), a change of an output from the temperature sensor (2) is detected when the surface of the liquid (3) comes into contact with the thermal sensing portion (2a) by temperature detecting means (5), and control means (6) determines that the liquid surface has reached a desired level and sends a pouring stop command to a pouring mechanism (7) to complete the filling of the liquid.
    Type: Grant
    Filed: May 12, 1995
    Date of Patent: February 25, 1997
    Assignee: Hoya Corporation
    Inventor: Masami Sasano
  • Patent number: 5603238
    Abstract: A floatless liquid level gauge assembly utilizing polymeric resistive/conductive elements is provided which measures the liquid level of partially conductive or conductive liquids in a tank using a three terminal voltage divider network or a two terminal voltage or current network. The polymeric resistive/conductive element(s) extending into the tank and the liquid in the tank provide an electrical path which provides a signal proportional to the liquid level in the tank.
    Type: Grant
    Filed: August 1, 1995
    Date of Patent: February 18, 1997
    Assignee: Rochester Gauges, Inc.
    Inventor: Cecil M. Williamson
  • Patent number: 5602333
    Abstract: A fuel gauging system for use in determining the level of fuel in a tank. The system incorporates a resonant circuit for measuring the resonant frequency of at least one probe immersed in the fuel located in the tank. From measurements of variations of the frequency of resonance, the level of liquid in the tank is determined, and the fuel quantity is then calculated and displayed.
    Type: Grant
    Filed: June 17, 1994
    Date of Patent: February 11, 1997
    Assignee: Smiths Industries
    Inventors: David A. Larrabee, John S. Wyler, Farid Ahmad
  • Patent number: 5593949
    Abstract: Method and arrangement for detecting the level of a liquid cryogen having a predetermined boiling point and which is being held in a container relative to the bottom of the container. The arrangement includes a container which receives the liquid cryogen and a longitudinal extending sensing member having a length extending from the bottom of the container to a level that is greater than any depth experienced for the liquid cryogen. The sensing member is vertically disposed in the container with one end in contact with the bottom of the container and the other end extending out of the liquid cryogen. The sensing member is composed of a high temperature superconductor material having a critical temperature that is higher than the predetermined boiling point of a selected cryogen. An electrical current is passed through the sensing member and the voltage drop across the sensing member is measured.
    Type: Grant
    Filed: May 31, 1994
    Date of Patent: January 14, 1997
    Assignee: Lockheed Martin Corporation
    Inventors: Eddie M. Leung, Kenneth R. Dawson
  • Patent number: 5576582
    Abstract: An automatic pump control for a pump such as a marine vessel bilge pump uses solid state components and has no moving parts. A first integrated logic device activates an FET transistor and completes a circuit which turns the pump on when the water reaches a predetermined high level and in association with an interconnected second integrated logic device keeps the pump on until the water subsequently reaches a predetermined low level. The control can be manually operated and includes circuitry to activate a high water alarm. The switch housing is molded in a manner which permits mounting directly to the pump.
    Type: Grant
    Filed: September 15, 1994
    Date of Patent: November 19, 1996
    Inventor: Paul S. White
  • Patent number: 5565851
    Abstract: A fluid level sensing system, particularly for sensing the water level in a steam generating boiler, comprises a vessel connected to the boiler so as to contain water and steam at substantially the same level as in the boiler, a number of vertically spaced electrodes projecting into the vessel, and circuitry for measuring the electrical impedance sensed by each electrode. The circuitry, which can be multiplexed to each electrode in turn, includes a first comparator for producing an output when the sensed impedance lies between the normal maximum impedance of the water and the normal minimum impedance of the steam above the water, this output being demultiplexed to drive a vertical display to show the level of the steam/water interface. The circuitry additionally includes a second comparator for producing a further output when the sensed impedance lies below the normal minimum impedance of the water, which further output is indicative of a variety of different fault conditions and drives a fault indicator.
    Type: Grant
    Filed: January 18, 1996
    Date of Patent: October 15, 1996
    Assignee: Solartron Group Limited
    Inventors: Paul N. Richards, Stephen P. Howse
  • Patent number: 5564305
    Abstract: A column of liquid is formed in a conduit for such liquid, of which flow-off amount gives then between two level measuring probes a constant value. This constant value is compared with the indicated value of a flow meter arranged in the conduit regarding the conformity in order to detect if the value indicated by the flow meter lies within a tolerance range or not. In the latter case, the error indication of the flow meter is too large and the liquid conduit is shut off. This controlling is made in arbitrary intervals automatically by the apparatus, whereby the interval is set by the speed with which the liquid column is completed.
    Type: Grant
    Filed: April 17, 1995
    Date of Patent: October 15, 1996
    Assignees: Angelo Cadeo, Miteco AG
    Inventor: Angelo Cadeo
  • Patent number: 5553794
    Abstract: A sewage grinder pump system for use in moving sewage, having a vertically oriented cylindrical pump motor housing, a bottom plate affixed to and closing the pump motor housing, a motor supported by the bottom plate within the pump motor housing, the motor having a shaft extending through an opening in the bottom plate, a grinder pump supported to a lower end of the bottom plate and connected to the motor shaft, a closure member affixed to the pump motor housing top end and having a level detector receiving portion providing a liquid level detector opening therein externally of the pump motor housing, an elongated liquid level detector having an upper end received within the liquid level detector opening, and a circuit connecting the liquid level detector to control the motor to thereby drive the grinder pump in response to detected liquid level.
    Type: Grant
    Filed: December 22, 1994
    Date of Patent: September 10, 1996
    Assignee: Tarby Inc
    Inventors: Darrel S. Oliver, Deborah C. Wynn
  • Patent number: 5553494
    Abstract: A boiler water level system comprises a plurality of electrodes arranged to sense the resistivity of the fluid at each of a plurality of different levels in a pressure vessel. The pressure vessel is coupled to one end of the boiler such that the level of the water in the pressure vessel is substantially the same as the level in the boiler, and each electrode senses the resistivity of the fluid (ie water or steam) between the tip of the electrode and the wall of the pressure vessel. Such a system on its own inherently produces a digital output of relatively low resolution, so to improve resolution, and to provide an analogue output if desired, additional circuitry is provided to sense the progressive change in the impedance sensed by each electrode as the water rises to progressively immerse that electrode and then carries on rising towards the next electrode.
    Type: Grant
    Filed: May 27, 1994
    Date of Patent: September 10, 1996
    Assignee: Solartron Group Limited
    Inventor: Paul N. Richards
  • Patent number: 5541575
    Abstract: A leakage detection system is provided having a plurality of locally distributed integrated units with a leakage sensor, preprocessing unit, and evaluation unit which connects with the individual integrated units or with a group of integrated units via a serial bus line. In each preprocessing unit, the value measured by the leakage sensor is subjected to a temperature compensation process.
    Type: Grant
    Filed: July 21, 1994
    Date of Patent: July 30, 1996
    Inventor: Ulrich Virnich
  • Patent number: 5539670
    Abstract: A multiple set point material condition monitoring system is responsive both to the level of material with respect to a sensor and the extent of material coating which has accumulated on the sensor. The system provides an output when a predetermined coating thickness has been exceeded, so that the sensor may be cleaned before the coating can accumulate to the extent where a false level output is generated. The systems include three electrode guarded sensors, a bridge comparing the sensor output with a reference, and a bridge reference which is automatically and repeatedly caused to assume a sequence of values corresponding to material condition set points, one of which causes an output when a predetermined coating thickness has occurred and another of which generates a level output. In one embodiment, separate outputs are provided corresponding to each set point. In another embodiment, a single tri-state output is responsive to both set points.
    Type: Grant
    Filed: March 10, 1994
    Date of Patent: July 23, 1996
    Assignee: Drexelbrook Controls, Inc.
    Inventors: Frederick L. Maltby, L. Jonathan Kramer, Steven R. Petersen
  • Patent number: 5532527
    Abstract: A level switch includes an operational amplifier, provided with positive and negative feedback, and a sensor, together forming an astable multivibrator. The oscillation onset and frequency of the multivibrator depend on the surface level of controlled material. The sensor includes a dielectric body on which, starting from its fastening end, a grounded opposite electrode and a screening electrode, connected to the amplifier output, are mounted. A ring plate connected to the inverting amplifier input is incorporated coaxially in the dielectric body. The level switch need not be adjusted when the controlled material is changed, although materials may have quite different electrical properties and may stick to the sensor.
    Type: Grant
    Filed: January 13, 1993
    Date of Patent: July 2, 1996
    Inventors: Andrej Zatler, Franc Eferl
  • Patent number: 5526026
    Abstract: A continuous ink jet printer employing conductive ink and having a main ink supply, a supplemental ink supply, and a replenishment carrier fluid supply includes a fluid system that replenishes ink or carrier fluid based on the resistivity of ink in the main ink supply.
    Type: Grant
    Filed: March 17, 1994
    Date of Patent: June 11, 1996
    Assignee: Scitex Digital Printing, Inc.
    Inventor: Mark C. Bowers
  • Patent number: 5513527
    Abstract: An ultrasonic fuel-gauging system for an aircraft with three fuel tanks has probes in each tank connected to dual-lane data concentrator circuits. The digital outputs from one lane of the data concentrator circuits are supplied to respective tank circuits, the outputs of which are connected to two input/output circuits. The outputs of the other lanes of the data concentrator circuits are connected directly to one or the other of the two input/output circuits. The tank circuits and input/output circuits are processors of identical construction programmed with different software. If a tank circuit or input/output circuit should fail, its function is taken over by reconfiguration of one of the remaining processors.
    Type: Grant
    Filed: May 3, 1995
    Date of Patent: May 7, 1996
    Assignee: Smiths Industries Public Limited Company
    Inventor: David M. Griffiths
  • Patent number: 5501102
    Abstract: A floatless liquid level gauge assembly utilizing polymeric resistive/conductive elements is provided which measures the liquid level of partially conductive or conductive liquids in a tank using a three terminal voltage divider network or a two terminal voltage or current network. The polymeric resistive/conductive element(s) extending into the tank and the liquid in the tank provide an electrical path which provides a signal proportional to the liquid level in the tank.
    Type: Grant
    Filed: November 24, 1993
    Date of Patent: March 26, 1996
    Assignee: Rochester Gauges, Inc.
    Inventor: Cecil M. Williamson
  • Patent number: 5493877
    Abstract: A water level sensor and alarm system for use with a washing machine. The water level sensor and alarm system includes a control box, a control circuit, a plurality of probes, and a washing machine unit and drain. The low level sensor and alarm system will connect directly to a washing machine and drain tub and/or drain conduit in order to monitor an overflow of water during the rinse cycle of a washing machine. If water has exceeded a certain height, and is beginning to overflow, the system will automatically cut all power to the washing machine unit and thus turn the washing machine unit off until the unit is reset after the clog in the drain has been corrected.
    Type: Grant
    Filed: October 5, 1994
    Date of Patent: February 27, 1996
    Inventor: Daniel R. Wickremasinghe
  • Patent number: 5488395
    Abstract: A liquid jet recording apparatus includes an ink container. A pair of electrodes are provided to be immersed in the ink in the container. By applying a voltage between the electrodes, the remainder of the ink is detected by a change in the electric resistance between the electrodes. The voltage application is not continuous but is intermittent and is performed at a predetermined time associated with the recording operation (at the time of carriage reversal) to detect the remainder of the ink. When the ink remainder detecting operation is not performed, the voltage is not applied to the electrodes. During a stand-by period the execution of the remainder of ink detection process is carried out only once to prevent degradation of the ink caused by electrolysis.
    Type: Grant
    Filed: September 12, 1994
    Date of Patent: January 30, 1996
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yoshiaki Takayanagi, Asao Saito, Ryoichi Koizumi
  • Patent number: 5485401
    Abstract: The present invention resides in a probe excitation and testing ("PET") system that can apply either a normal excitation or a "small" bias test excitation to overfill protection probes mounted within storage and transport tanks used to store, e.g., flammable fluids. The PET system applies the normal excitation for normal operation of the probes to provide overfill protection, and applies a "small" bias test excitation to the probes for performing diagnostic tests, including anti-cheating. The PET system can also perform a probe signature validation test under normal excitation to ascertain whether the probes are responding thereto in accordance with specifications relating to characteristic parameters of the probes' output waveforms, e.g., duty cycle, magnitude, and period.
    Type: Grant
    Filed: June 14, 1993
    Date of Patent: January 16, 1996
    Assignee: Scully Signal Company
    Inventor: Gary R. Cadman
  • Patent number: 5465610
    Abstract: A device for the characterization of the foaming properties of a product at least partially soluble in a liquid comprising a transparent analysis column (1) provided at its base with a porous allowing filter (2) to homogeneously introduce a gas flow through the column to effect foaming of the product (3) located at the base of the analysis column (1) characterized in that it further comprises an automatic measuring system (28) to determine the foam height in column (1), an automatic measuring system (24, 24', 25) to determine the volume of product (3) to form the foam, means to visualize and/or to process the measured data and a pressure compensation system to avoid drainage and percolation of product (3) through filter (2) when gas injection is stopped.
    Type: Grant
    Filed: December 7, 1993
    Date of Patent: November 14, 1995
    Assignee: Institut National de La Recherche Agronomique
    Inventor: William G. Loisel
  • Patent number: 5450067
    Abstract: A water level detector and indicator system includes a water level detector and a water level display controlled by the water level detector to give a respective output signal when the level of water changes from one position to another. The water level detector can be a mechanical type which uses a float to control a multi-step switch causing a series of indicator lamps to give light respectively. The water level detector can be an electronic type which uses metal probes to detect the change of water level, and a controller driven by the metal probes to control buzzers and indicator lamps to work.
    Type: Grant
    Filed: April 21, 1994
    Date of Patent: September 12, 1995
    Inventor: Ping-Shin Wang
  • Patent number: 5447056
    Abstract: An "L" shaped element having horizontal and vertical sections, is submerged in the liquid toner concentrate such that the horizontal section is totally submerged while the vertical section is submerged proportionally to an amount of the liquid toner concentrate. A voltage source is connected to the "L" shaped element. A second element is placed in close proximity to the horizontal section of the "L" shaped element and is also totally submerged in the liquid toner concentrate. Next, a third element is placed in close proximity to the vertical section of the "L" shaped element. The current flowing from the horizontal section of the "L" shaped element through the liquid toner concentrate to the second element is proportional to the concentration of solid. By measuring the current flowing from the vertical section of the "L" shaped element through the liquid toner concentrate to the third element and dividing by the current in the second plate, the volume of the liquid toner concentrate can easily be calculated.
    Type: Grant
    Filed: June 3, 1994
    Date of Patent: September 5, 1995
    Assignee: Hewlett-Packard Company
    Inventor: Wayne E. Foote
  • Patent number: 5438323
    Abstract: A fail safe output stage for a tank fluid level detection circuit having power supply/output leads periodically places a shunt across the leads to periodically generate a LOW signal which alternates with a HIGH signal to indicate an underfilled condition. In a filled condition, a steady signal appears across the leads. The output stage of the detection circuit consists of a parallel connection of switching devices where the "on" impedance of any single switching device is insufficient to place the detection circuit output lead in a LOW logic state. Therefore, in a condition where one of the switching devices fails, the detection circuit output may continue to alternate, but the alternating output is not recognized as such by a disable circuit which does not detect a LOW logic condition on the output lead. Accordingly, the failed output is interpreted as an filled condition, resulting in a shutdown of the system.
    Type: Grant
    Filed: June 14, 1993
    Date of Patent: August 1, 1995
    Assignee: Scully Signal Company
    Inventor: Arthur W. Shea
  • Patent number: 5428348
    Abstract: A battery-operated fluid level monitor has a novel circuit and sensor for providing signals, both audible and visible, for indicating low fluid level, low battery voltage, and proper fluid level. The monitor is useful as a device that can inform when a Christmas tree needs water. The monitor can also be economically fabricated, and this is important for mass production applications, such as a Christmas tree monitor.
    Type: Grant
    Filed: August 30, 1993
    Date of Patent: June 27, 1995
    Assignee: Holiday Safety, Inc.
    Inventor: Robert L. Gault
  • Patent number: 5415042
    Abstract: A measuring probe to detect the presence of electrically conducting liquid or granular material includes a first metal electrode (4) comprising a tube (5) which is adhered to a porous, ceramic insulator (12) adhered in turn to a skirt (10) forming a second metal electrode (6). First electrode (4) is connected to a gas supply (58) supplying gas, for example nitrogen, under pressure which emerges into a space (26) in the probe and which then passes through insulator (12) to emerge from face (20) thereof. A heat resistant cable (46) has its conductor (52) brazed to cap portion (8) of second electrode (6). Cable (46) and first electrode (4) are connected into an electrical circuit (66) in which current flows when a conducting bridge of granular material simultaneously contacts both electrodes (4 and 6). Should the level of the granular material drop below second electrode (6), gas emerging from face (20) blows away any granular material trying to preserve the conducting bridge, and circuit (66) is interrupted.
    Type: Grant
    Filed: April 22, 1993
    Date of Patent: May 16, 1995
    Assignee: British Gas plc
    Inventors: Harry Gray, Barry L. Price
  • Patent number: 5408223
    Abstract: A two-level detector for an electrically conductive liquid having a common electrode serving as a potential reference and situated at a low level, a high electrode situated at a high level, and a low electrode situated at the low level, the electrodes being connected by conductors to electronic apparatus for detecting the liquid at said two levels by means of currents flowing through the liquid. The high and low electrodes are made of metals that have different electrode potentials. A first conductor and a second conductor interconnect the electrodes to constitute an electrical primary cell that is short-circuited when both electrodes are simultaneously in contact with the liquid. The second conductor is extended to connect the electrode assembly to a signal terminal of the electronic apparatus. The common electrode is made of a metal whose electrode potential is different by about 0.
    Type: Grant
    Filed: July 27, 1993
    Date of Patent: April 18, 1995
    Inventor: Gilbert Guillemot
  • Patent number: 5404048
    Abstract: The invention relates to a liquid sensing switch for use primarily in sensing the bilge water level aboard a boat. The switch is designed with a high input impedance and a high trigger sensitivity, so that the presence of a liquid may be detected by using a remotely located single wire probe. The probe is able to sense immersion into low conductivity liquids or into liquids where no hardwired ground is provided, such as within fiberglass boat hulls. In order to prevent false triggering and cyclic operation of the bilge pump, the liquid sensing switch provides a time delay before it is activated, as well as a further time delay before being deactivated.
    Type: Grant
    Filed: August 6, 1993
    Date of Patent: April 4, 1995
    Assignee: Aim Technologies, Inc.
    Inventor: Edward J. Panner
  • Patent number: 5400651
    Abstract: An apparatus and method for measuring the water level at the bottom of a storage tank, the water level being the product-water interface between product and water within the storage tank. The apparatus includes a sensor assembly which is located at the tank bottom. The assembly has a plurality of measurement sensors arranged in a housing having slots for product and water to enter and leave the housing. Each measurement sensor is an open-circuited co-axial transmission line with a probe at its open end which functions as a monopole antenna. In preferred embodiments, the transmission lines are quarter wavelength open-circuited coaxial transmission lines. Each probe is located at a different distance from the tank bottom to cover a measurement range. The transmission lines are excited with signals which are reflected by the probes.
    Type: Grant
    Filed: June 1, 1994
    Date of Patent: March 28, 1995
    Assignee: Shell Oil Company
    Inventor: Michael Welch
  • Patent number: 5365220
    Abstract: A warning device is disclosed for an evaporative cooler or swamp cooler. The alarm comprises a pair of closely spaced electrodes mounted at a desired position above the floor of a water reservoir in the evaporative cooler. During normal operation of the evaporative cooler, the electrodes are not submerged in the pater. Upon malfunction of the float valve in the water supply to the reservoir, uncontrolled amounts of water are added to the reservoir, and the water level rises. When the water level attains a specified depth, the electrodes become submerged in the water. An electrical circuit is associated with the electrodes, and when the electrodes become submerged in the water, the electrical circuit is closed. The closing of the circuit activates an audible alarm which can be heard by inhabitants in the building being served by the evaporative cooler. Preventive maintenance can then be undertaken before extensive damage is done by water overflowing from the water reservoir of the evaporative cooler.
    Type: Grant
    Filed: September 4, 1992
    Date of Patent: November 15, 1994
    Inventor: Steven C. Rasmason
  • Patent number: 5333498
    Abstract: Apparatus and method are disclosed for measuring the quantity of a liquid, such as crude oil, transferred to or from a storage tank with all measurements being taken through an opening near the bottom of the tank. A water detecting probe is extendable through the opening a selected distance below the opening in order to detect the presence of water at a selected level below the opening and generate a detection signal. A sampling device is connectable to the opening for taking samples of the liquid transferred to or from the tank. A pressure sensor is connected to the opening for generating a pressure signal indicative of the pressure of the liquid in the tank. A computer is provided for using the pressure signal to generate a level signal indicative of the level of the liquid in the tank.
    Type: Grant
    Filed: June 19, 1992
    Date of Patent: August 2, 1994
    Assignee: W. L. Walker Co., Inc.
    Inventors: Anne W. Brackett, Marcus O. Durham, Lynn K. Perkins, Gregory E. Thoman
  • Patent number: 5329304
    Abstract: A device for detecting a quantity of remaining ink includes first and second electrodes provided in an ink supply passage which connects an ink tank for storing an ink to a recording head for emitting the ink, and a detection means for detecting a resistance between the first and second electrodes. The second electrode is provided in the ink supply passage in an area relatively close to the recording head, whereas the first electrode is provided in the ink supply passage in an area relatively far from the recording head with the second electrode therebetween. The second electrode is maintained at the same potential as that of a substrate which constitutes the recording head and on which emission energy generating elements driven to emit the ink are disposed, whereas the first electrode is maintained at a potential different from that of the second electrode. Consequently, the amount of remaining ink can be detected by measuring changes in the resistance between the first and second electrodes.
    Type: Grant
    Filed: March 16, 1992
    Date of Patent: July 12, 1994
    Assignee: Canon Kabushiki Kaisha
    Inventors: Ryoichi Koizumi, Asao Saito
  • Patent number: 5327997
    Abstract: A lubrication management system controls the lubricant quantity in multiple refrigeration compressor lubricant sumps. A buoyant member is placed in the lubricant, where a float portion and a magnetically conductive portion rise or fall together. The sensor further includes a displacement transducer producing a variable electrical signal through a resonant frequency shift. The displacement transducer, in proximity with the magnetically conductive portion of the buoyant member, transforms motion of the magnetically conductive portion to changes in resonant frequency shift in proportion to the position of the magnetically conductive element relative the displacement transducer. The system also includes circuitry for receiving the signal and comparing the signal to an adjustable set point, from which the circuitry determines whether an output for signalling a need for additional lubricant is necessary.
    Type: Grant
    Filed: January 22, 1993
    Date of Patent: July 12, 1994
    Assignee: Temprite, Inc.
    Inventors: Robert V. Nash, Jr., Bruce E. Meyer
  • Patent number: 5321633
    Abstract: To eliminate an ambient temperature correcting sensor and further to improve the sensor response speed in a heat radiating type liquid level sensing system, a constant current pulse is periodically passed through a level sensor to heat it; level sensor voltages sampled at predetermined time intervals when the level sensor is being heated are divided by each initial sensor voltage to obtain sensor voltage ratios with respect to time; an approximate voltage is calculated on the basis of the the obtained ratios in accordance with an approximation equation; a liquid level is calculated and displayed on the basis of the calculated approximate sensor voltage. Further, it is preferable that the system is provided with an additional inclination correcting sensor or an acceleration sensor, in order to correct the inclined liquid level.
    Type: Grant
    Filed: May 21, 1992
    Date of Patent: June 14, 1994
    Assignee: Yazaki Corporation
    Inventors: Ichiro Kataoka, Naoto Ishikawa, Yoshihito Aoki
  • Patent number: 5315317
    Abstract: An ink quantity detecting device includes a plurality of ink chambers for containing inks, displacement members each provided for a corresponding one of the ink chambers and capable of being displaced in accordance with a quantity of a corresponding ink, a coupling member for coupling a plurality of displacement members, and a detecting unit for detecting displacement of at least one of the displacement members or the coupling member. The coupling member can be displaced in accordance with a quantity of at least one ink.
    Type: Grant
    Filed: September 15, 1993
    Date of Patent: May 24, 1994
    Assignee: Canon Kabushiki Kaisha
    Inventors: Koji Terasawa, Makoto Takemura, Takashi Nojima, Akira Miyakawa
  • Patent number: 5304985
    Abstract: A water level sensing probe which comprises a central electrode encircled by a tubular ceramic insulator which is held between an integral laterally projecting portion of the electrode, which forms a conductive tip, and a tubular metal mounting body which surrounds and is displaced from the electrode that passes through it. The ceramic insulator is taper locked within the conductive tip at one end and within the tubular metal mounting body at the other end.
    Type: Grant
    Filed: April 16, 1992
    Date of Patent: April 19, 1994
    Inventor: Harry F. Cosser
  • Patent number: 5289211
    Abstract: The ink detecting device gives advance warning of the end of the ink in a reservoir or cartridge feeding an ink-jet thermal print head. The device comprises a pair of electrodes that are immersed in a spongy, ink-soaked body contained in the reservoir, and are arranged in a region adjacent to the feed duct at which the spongy body has a 30% to 100% higher capillarity than in remote regions. The electrodes are connected to a bridge circuit which measures the electrical resistance of the ink between the two electrodes.
    Type: Grant
    Filed: April 17, 1992
    Date of Patent: February 22, 1994
    Assignee: Ing. S. Olivetti & C., S.p.A.
    Inventors: Roberto Morandotti, Alessandro Scardovi
  • Patent number: 5287086
    Abstract: A proximity detection system includes a dual mode oscillator for generating a pair of ON and OFF control signals. A sensing circuit including a capacitance device detects the presence of a conductive object, such as a liquid, to cause the oscillator to switch its modes of oscillation.
    Type: Grant
    Filed: September 23, 1991
    Date of Patent: February 15, 1994
    Assignee: Raptor, Inc.
    Inventor: Robert F. Gibb
  • Patent number: 5272921
    Abstract: A probe for monitoring a liquid level has a one-piece insulation sheath extended within the probe casing and positioned far beyond the end of a contact pressure spring that is removed from the liquid. This contact pressure spring has an associated spring abutment formed by either a sleeve or a cap surrounding the insulation sheath. In the probe casing, lengthy sections of insulation are present such that functional interferences are avoided. The probe casing has large-dimensioned ventilation apertures for preventing moisture films.
    Type: Grant
    Filed: March 5, 1993
    Date of Patent: December 28, 1993
    Assignee: GESTRA Aktiengesellschaft
    Inventors: Werner Foller, Helmut Willenbrock, Wolfgang Behnken
  • Patent number: 5272919
    Abstract: A method for measuring the level of filling, such as the level of oil in an automotive engine, employs a hot-wire measuring device in which a hot-wire transmitter (5) is charged with a predetermined constant current, and an increase in voltage over the hot-wire transmitter is detected within a predetermined period of time. Errors due to digitizing and inaccurate calibration are avoided by the simplest possible means. For this purpose, a current source (1), which is controlled by an input voltage, is used as a source of the constant current. Furthermore, in a preparatory stage, after an assembly of the hot-wire measuring device, an input voltage (PWM) is changed until, at an input-voltage value wherein the current source (1) produces the predetermined constant current (IK). The input-voltage value is used in subsequent measuring stages to control the source of current.
    Type: Grant
    Filed: April 2, 1992
    Date of Patent: December 28, 1993
    Assignee: VDO Adolf Schindling AG
    Inventor: Thomas Herm
  • Patent number: 5263370
    Abstract: A liquidometer composed of a siphon for emitting a sample liquid stored in a reservoir and a liquid level sensor for sensing the level of the sample remained in the reservoir. The siphon further includes a pair of sensors for counting the number of emission thereof, while the liquid level sensor includes two rows of resistive film with a plurality of sensing elements embedded therein. Outside the liquidometer, there are provided a counter connected to the emission sensor, a level calculator connected to the liquid level sensor, and a calculator coupled to both. A gross amount of the sample liquid having been measured for a period of hours is obtained by adding together a count signal from the counter which represents the quantity of the sample liquid fully stored in the reservoir and a signal from the level counter which represents the liquid level of the remaining sample liquid.
    Type: Grant
    Filed: April 29, 1991
    Date of Patent: November 23, 1993
    Assignee: Murata Mfg. Co., Ltd.
    Inventors: Michihiro Murata, Akira Kumada, Kenji Matsuo, Shigeo Yamazaki
  • Patent number: 5255021
    Abstract: In an ink-jet printer of the type wherein a current is passed through a conductive ink contained between a pair of electrodes to cause the ink to become vaporized and cause trapped gasses or bubbles to expand suddenly, exerting a sufficient pressure upon the ink to force droplets of ink from a nozzle, a current value flowing between the electrodes is detected to determine the amount of wear of the electrodes, and when the detected current value is lower than a predetermined value, an alarm indicative of the replacement of the currently used ink-jet head is given and, at the same time, ejection of the ink from the nozzle is stopped. Thus, printing operation is always achieved with stable ejection of ink, guaranteeing high printing qualities.
    Type: Grant
    Filed: April 1, 1992
    Date of Patent: October 19, 1993
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tomoyuki Noguchi, Mitsuhide Matsuda, Tadashi Shiraishi, Hideaki Horio
  • Patent number: 5255019
    Abstract: In an ink near-end detecting device, a pair of electrodes are arranged in the porous material in the ink tank and in the ink pool provided below the ink tank, respectively, so that the time instant the ink in the porous material has been nearly used up is detected from the variation of the electrical resistance between the electrodes with the consumption of the ink in the porous material.
    Type: Grant
    Filed: August 7, 1991
    Date of Patent: October 19, 1993
    Assignee: Seiko Epson Corporation
    Inventors: Seiji Mochizuki, Takahiro Naka, Kazuhiko Hara, Akira Takagi, Yukihiro Hanaoka
  • Patent number: 5249463
    Abstract: A water level measurement system for use with a pressurized power plant boiler comprises a tubular pressure vessel for attachment to one end of the boiler such that the water level in the pressure vessel is the same as in the boiler. The pressure vessel has a central rod-like conductor which together with the vessel forms a coaxial RF waveguide. A pair of spaced reference discontinuities are provided in the conductor above the maximum level of the water, so that an RF pulse injected into the waveguide is reflected successively by both discontinuities and the surface of the water. The level of the water can then be determined independently of changes in the dielectric constant of the vapor above it, from the ratio between the time intervals between the first and second reflected pulses and between the first and third reflected pulses. The conductor is mounted at the top of the pressure vessel by way of a pressure seal and a ceramic insulator.
    Type: Grant
    Filed: September 21, 1992
    Date of Patent: October 5, 1993
    Assignee: Schlumberger Industries Limited
    Inventors: Jolyon P. Willson, Paul N. Richards
  • Patent number: 5233869
    Abstract: A fire fighting trainer for use in training fire fighters is provided. The fire fighting trainer includes a structure having one or more chambers having concrete or grating floors. Each chamber contains one or a series of real or simulated items such as furniture and fixtures and equipment. The trainer has a smoke generating system with an outlet for each chamber. The trainer also includes a propane gas flame generating system. The trainer has a main control panel for regulating the flame generating system and the smoke generating system and for controlling the fire, or fires, and smoke in each chamber. The trainer also has a sensor assembly in each chamber, which senses water.
    Type: Grant
    Filed: April 24, 1992
    Date of Patent: August 10, 1993
    Assignee: Symtron Systems, Inc.
    Inventors: William Rogers, James J. Ernst, Steven Williamson, Dominick J. Musto
  • Patent number: 5233329
    Abstract: A circuit including a sender providing a sender output signal responsive to a vehicle parameter, circuitry for providing an adjustable reference, circuitry for comparing the output signal to the adjustable reference and providing a comparison output signal therefrom, an up/down counter for filtering the comparison output signal, and circuitry for providing an indicator control signal in response to the filtered output signal and for controlling the adjustment of the adjustable reference, provides a signal to a vehicle operator that is both filtered and has hysteresis to minimize repeated switching of the signal between two states.
    Type: Grant
    Filed: August 27, 1991
    Date of Patent: August 3, 1993
    Assignees: Delco Electronics Corporation, Hughes Aircraft Company, General Motors Corp.
    Inventors: Raymond Lippmann, James E. Nelson, Michael J. Schnars, James R. Chintyan, James M. Aralis, Frank J. Bohac, Jr., Anthony L. Simon
  • Patent number: 5230563
    Abstract: A liquid monitoring device includes means for detecting the presence of a liquid and means for giving an alarm when the liquid is detected. Preferably a temperature sensor is also provided and the temperature is displayed on an LCD. The temperature sensor is arranged to sense the ambient air temperature at a first sampling rate and then the liquid temperature, after the liquid has been detected by a detector, at a second, more frequent sampling rate. The components are housed in a casing which carries a pivotably mounted sucker for attachment to a wall or bath.
    Type: Grant
    Filed: December 31, 1991
    Date of Patent: July 27, 1993
    Assignee: Solar Wide Industrial Ltd.
    Inventor: Ram Shalvi
  • Patent number: 5229751
    Abstract: A perishable fluid container assembly is disclosed as including a timing mechanism in conjunction with a coffee pot, wherein a visible indicator device is energized while the coffee within the pot remains fresh. When the coffee pot is filled with fresh coffee, the visible indicator device first becomes energized, and stays energized even though the coffee pot is temporarily tipped on its side for the dispensing of coffee. After the predetermined time duration has expired, the visible indicator device is de-energized to indicate that the character or freshness of the coffee has expired. Additionally if the coffee pot becomes empty, the visible indicator device becomes de-energized after a short time delay.
    Type: Grant
    Filed: November 8, 1991
    Date of Patent: July 20, 1993
    Inventors: Curt M. Chandler, Rick G. Hubbard, Jerry E. Cravens