Liquid Level Responsive Patents (Class 200/190)
  • Patent number: 10393292
    Abstract: The invention relates to a method of manufacturing a pipe segment for a link tube between the sea floor and a petroleum drilling rig disposed on the sea surface, wherein it consists in: providing a transport pipe segment that is resistant to open-sea conditions; disposing a female bayonet-piece around one reinforced end of the transport pipe segment; welding or otherwise bonding a narrower portion of the bayonet-piece to said reinforced end; disposing an insulator around the transport pipe segment and around the bayonet-piece; inserting the transport pipe segment into an outer wall segment; welding or otherwise bonding a narrower portion of the outer wall segment to the other reinforced end of the transport pipe segment; disposing a cover-piece around the bayonet-piece; welding or otherwise bonding the cover-piece to the outer wall segment and to the bayonet-piece; it being possible to apply tightening torque to the outer wall segment and to transmit it to the transport pipe segment.
    Type: Grant
    Filed: September 8, 2016
    Date of Patent: August 27, 2019
    Assignee: ITP SA
    Inventors: Pierre Ollier, Jean-Aurélien Damour
  • Patent number: 10201979
    Abstract: A fluid level sensor has a sensing element mounted to the end of a member that requires a predetermined orientation for accurate fluid level detection. A knob on the housing of the sensor operatively connected to the member includes an orientation indicator. The member includes a thread that extends a distance along the member that corresponds to a thickness of the wall into which the member of the fluid level sensor is inserted. A portion of the thread extends beyond the wall to enable bidirectional rotation of the knob to position the element for accurate fluid level detection while a portion of the thread remains within an opening in the wall to enable pressure to be applied to an O-ring seal mounted about the member to prevent leakage from the bore.
    Type: Grant
    Filed: August 14, 2017
    Date of Patent: February 12, 2019
    Assignee: Xerox Corporation
    Inventor: Blake T. Weimer
  • Patent number: 9677785
    Abstract: A fuel-fired condensing type air heating furnace is provided with an electronic condensate water level sensing system operative to sense improper outflow of condensate from a collector box portion of the furnace and responsively shut down or prevent operation of the furnace. Condensate probe portions of the system are oriented in a manner such that several air flow orientation of the furnace may be utilized without the necessity of relocating the probes or effecting an re-wiring of the water level sensing system.
    Type: Grant
    Filed: November 20, 2012
    Date of Patent: June 13, 2017
    Assignee: RHEEM MANUFACTURING COMPANY
    Inventors: Robert S. Neihouse, Shawn A. Reed, Walter R. Lowrimore, Randy R. Koivisto, Scott A. Willbanks
  • Patent number: 9335241
    Abstract: A monitoring system is configured for monitoring a property of a fluid. The monitoring system includes a vessel and a monitoring capsule. The vessel is configured for holding a volume of the fluid therein. The monitoring capsule is configured for disposition within the vessel. The monitoring capsule includes a housing, a hydrometer, and a sensor. The hydrometer is movably disposed within the housing. The hydrometer is configured to measure the property of the fluid. The sensor is operatively attached to the housing and configured to sense the measured property of the fluid.
    Type: Grant
    Filed: October 11, 2013
    Date of Patent: May 10, 2016
    Assignee: GM Global Technology Operations LLC
    Inventor: Jerry D. Loman
  • Publication number: 20090162211
    Abstract: A control switch incorporates a solid state transducer, a strain gauge. The transducer responds to a local environmental condition, such as fluid level, or pressure and exhibits a parameter change which can be detected as an electrical output. Control circuits coupled to the transducer can sense the parameter change and switch a source of electrical energy to a load in response thereto.
    Type: Application
    Filed: May 20, 2008
    Publication date: June 25, 2009
    Applicant: Metropolitan Industries, Inc.
    Inventors: John R. Kochan, JR., Casey Barker
  • Patent number: 7057507
    Abstract: A system for monitoring leaks in dwellings that includes a sensor which detects water flow. The system determines that a leak is occurring when water has flowed through a water line for longer than a preselected period of time. A central monitoring system receives a signal from a local system and the central monitoring system has an associated record for each dwelling to thereby allow flexible response to correct the leak.
    Type: Grant
    Filed: June 30, 2003
    Date of Patent: June 6, 2006
    Inventor: Robert L. Sandifer
  • Patent number: 7019235
    Abstract: Disclosed herein is a channel plate for a fluid-based switch. The channel plate is produced by 1) depositing a photoimagable dielectric layer onto a substrate, 2) photoimaging at least one channel plate feature on the dielectric layer, and 3) developing the dielectric layer to form the at least one channel plate feature in the dielectric layer, thereby forming the channel plate. Switches using photoimaged channel plates, and a method for making a switch with a photoimaged channel plate, are also disclosed.
    Type: Grant
    Filed: January 13, 2003
    Date of Patent: March 28, 2006
    Assignee: Agilent Technologies, Inc.
    Inventors: Marvin Glenn Wong, John F. Casey
  • Patent number: 6730866
    Abstract: An electrical relay array using conducting liquid in the switching mechanism. The relay array is amenable to manufacture by micro-machining techniques. In each element of the relay array, two electrical contacts are held a small distance apart. The facing surfaces of the contacts each support a droplet of a conducting liquid, such as a liquid metal. An actuator, coupled to one of the electrical contacts, is energized in a first direction to reduce the gap between the electrical contacts, causing the two conducting liquid droplets to coalesce and complete an electrical circuit. The actuator is then de-energized and the contacts return to their starting position. The liquid droplets remain coalesced because of surface tension. The electrical circuit is broken by energizing an actuator to increase the gap between the electrical contacts to break the surface tension bond between the conducting liquid droplets.
    Type: Grant
    Filed: April 14, 2003
    Date of Patent: May 4, 2004
    Assignee: Agilent Technologies, Inc.
    Inventors: Marvin Glenn Wong, Arthur Fong
  • Patent number: 6595051
    Abstract: An improved pressure activated control apparatus is provided for sensing fluid pressure and triggering one or more switches in response to the fluid pressure, as desired. The apparatus is designed to be placed within a fluid of a reservoir. The apparatus includes a first resilient member, such as a pliable rolling diaphragm or bellofram, having an outer surface exposed to the fluid and responsive to the fluid pressure. The pressure activated control apparatus includes a second resilient member, such as a spring with a chosen spring constant, k, that provides a biasing force against the diaphragm that is opposite the fluid pressure. A transducer is operative to monitor changes in pressure of gases within the apparatus causes by movement of the diaphragm. A controller is responsive to the transducer and selectable fluid level thresholds to activate pumps and/or valves for adjusting the level of the fluid in the reservoir.
    Type: Grant
    Filed: August 24, 2001
    Date of Patent: July 22, 2003
    Assignee: Chandler Systems, Inc.
    Inventor: William D. Chandler, Jr.
  • Patent number: 6523562
    Abstract: A control system for stopping a plumbing-related flooding situation in a building includes at least one sensor for accumulating water and producing a low voltage electrical control signal when sufficient water is accumulated. An actuating system receives the control signal and in turn routes 110 volt current to an electrically activated valve located in a main feed conduit of the plumbing system. The reopening of the valve is achieved by a manually operated electrical switch.
    Type: Grant
    Filed: January 11, 2002
    Date of Patent: February 25, 2003
    Inventor: Roger Harper
  • Patent number: 6488826
    Abstract: An electrode electrolyte system is provided that is capable of operating in slope sensors in a wide range of temperatures. The eletrolytic system is characterized by a stable conductivity at high temperature and by low toxicity. The slope sensor can be installed in a system containing an Nal solution in propylene carbonate, combined with platinum electrodes.
    Type: Grant
    Filed: September 10, 2001
    Date of Patent: December 3, 2002
    Inventors: Patrick Altmeier, Andreas Konrad
  • Publication number: 20020020624
    Abstract: An electrode electrolyte system is provided that is capable of operating in slope sensors in a wide range of temperatures. The eletrolytic system is characterized by a stable conductivity at high temperature and by low toxicity. The slope sensor can be installed in a system containing an Nal solution in propylene carbonate, combined with platinum electrodes.
    Type: Application
    Filed: September 10, 2001
    Publication date: February 21, 2002
    Inventors: Patrick Altmeier, Andreas Konrad
  • Patent number: 6275160
    Abstract: A flow detector includes solid state delay circuitry coupled to a flow indicating device. In response to flow being indicated, the delay circuitry is enabled. After a preset delay interval, if flow is still being indicated, an output signal can be generated. The flow indicating device can be a two-state mechanical switch. A mode setting element can be used to configure the detector for different types of installations.
    Type: Grant
    Filed: March 22, 2000
    Date of Patent: August 14, 2001
    Assignee: Pittway Corporation
    Inventor: Simon Ha
  • Patent number: 6084521
    Abstract: A flow detector includes solid state delay circuitry coupled to a flow indicating device. In response to flow being indicated, the delay circuitry is enabled. After a preset delay interval, if flow is still being indicated, electrical energy can be provided by a short circuit to an output device for the duration of indicated flow. The flow indicating device can be a two-state mechanical switch. A short circuit supplying switch can be implemented as a solid state or mechanical latching relay. The flow detector circuits can be used independently to provide local alarms. Alternately they can provide alarm indicating signals to a common alarm control panel.
    Type: Grant
    Filed: April 13, 1998
    Date of Patent: July 4, 2000
    Assignee: Pittway Corporation
    Inventor: Simon Ha
  • Patent number: 5815079
    Abstract: A description is given of a sturdy device for establishing and/or monitoring a predetermined filling level in a container, which device exhibits a housing (1), two oscillating rods (3, 4) projecting into the container, a first diaphragm (2) which is fixedly clamped, at its border, into the housing (1), a second diaphragm (6, 6') which is arranged parallel to said first diaphragm in the interior of the housing (1), a piezoelectric element (7, 7') which is arranged on the second diaphragm (6, 6') and is intended for receiving and converting oscillations into an electric output signal and for inducing bending oscillations in the second diaphragm (6, 6'), and in the case of which device the mode of oscillation produced by the piezoelectric element (7, 7') corresponds to the mode of oscillation utilized for inducing oscillation in the oscillating rods (3, 4).
    Type: Grant
    Filed: May 1, 1996
    Date of Patent: September 29, 1998
    Assignee: Endress + Hauser GmbH + Co.
    Inventors: Igor Getman, Sergej Lopatin
  • Patent number: 5751074
    Abstract: An electrical switch sensitive to an externally applied inertial and gravitational force, having an enclosure with a closed space; a conductive fluid filing a first portion of the space and a non-conductive medium filling a second portion of the space, the conductive fluid and the non-conductive medium having differing densities; at least two electrodes in communication with the space; an electrical circuit coupled the contacts and having electrical connections for connection with a power source and a load, having a semiconductor switching device, which is responsive to a current through the contacts, a current through the contacts causing the semiconductor switching device to change in conductivity. An externally applied force, e.g., gravity or inertial force, causes the conductive fluid to move within the enclosure with respect to the contacts, altering a current through the contacts, and thereby changing a conducting state of the semiconductor switching device.
    Type: Grant
    Filed: September 8, 1995
    Date of Patent: May 12, 1998
    Assignee: Edward B. Prior & Associates
    Inventors: Edward B. Prior, Anthony J. Caristi, Luis A. Lazo, John E. Prior
  • Patent number: 5727421
    Abstract: An apparatus and method for providing liquid and gas proof sealing between a metal rod and a plastic housing molded there around. The rod includes a plurality of annular intrusions or protrusions along a length thereof. The plastic material is formed around the rod and the annular intrusions or protrusions. After the plastic material has cooled the rod is translated linearly with respect thereto whereby the annular intrusions or protrusions cause a cold flow movement or disruption of the plastic material. This movement results in a liquid and gas tight sealing between the rod and the plastic housing. The invention herein has particular application for liquid level sensing probes located within gas pressurized vessels. In such examples the rod or rods are used for sensing liquid level by means of electrical conductivity with the sensed liquid.
    Type: Grant
    Filed: February 10, 1995
    Date of Patent: March 17, 1998
    Assignee: IMI Cornelius Inc.
    Inventor: George W. Murphy
  • Patent number: 5506564
    Abstract: A marine craft fuel alert system is operative during a given time period, to compare actual fuel capacity measurements with selected fuel tank capacity reference values, to permit timely intervention. Used with a relatively high reference value and operative during fuel loading, the system and methodology gives a warning to a fuel input agent (i.e., person controlling fuel loading) in sufficient time for the agent to terminate fuel loading and prevent environmental pollution by fuel overfill spillage. Conversely, the system and methodology, with appropriate modifications, can be used to sense and warn of predetermined low fuel level conditions. The system can be integrally incorporated into an original equipment marine craft system or retrofit thereto. Electrical interconnections may extend to marine craft ignition system interdiction during operation of the fuel loading monitoring and warning.
    Type: Grant
    Filed: February 1, 1994
    Date of Patent: April 9, 1996
    Inventor: Thomas S. Hargest
  • 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: 5267580
    Abstract: A conveyor dishwashing machine in which racks of dishes are conveyed from a loading surface through a hood which presents washing and rinsing zones and onto a discharge surface. In the washing zone, wash spray is applied to the dishes from a spray system which is easily removed for cleaning and easily replaced in the proper position. In the rinsing zone, a rinse curtain applies an initial rinse and creates a barrier against the wash spray. A final rinse of clean city water is applied subsequent to the rinse curtain. Automatic controls operate the machine with a minimum of human intervention.
    Type: Grant
    Filed: November 2, 1992
    Date of Patent: December 7, 1993
    Assignee: TCA, Inc.
    Inventor: Russell L. Payzant
  • Patent number: 5239285
    Abstract: A low salt level sensor comprising a float within a brine tank, apparatus for detecting whether the float has risen in response to the addition of a predetermined amount of water to the brine tank to a height such that an adequate supply of salt is present in said brine tank and apparatus for indicating if the float has not risen high enough. A method of detecting whether the salt level is low in the brine tank of a water treatment system is also described. According to this method, brine is removed from the brine tank and a predetermined amount of water is added. A determination is then made as to whether the brine level has reached a height such that an adequate supply of salt is present in the brine tank and an indication is provided if the brine level is below this height.
    Type: Grant
    Filed: September 21, 1990
    Date of Patent: August 24, 1993
    Assignee: Culligan International Company
    Inventor: Stanley F. Rak
  • Patent number: 5198628
    Abstract: A tilt switch comprises a housing forming a cylindrical inner chamber and having two electric terminals extending through an end wall of the chamber. A mercury mass of less volume than the chamber is disposed within the chamber and is arranged to electrically interconnect the terminals when the switch is in a first position relative to vertical, and to break the electrical contact when the switch is tilted to a second position relative to vertical. A spherical body of less density than the liquid and including a non-electrically conductive outer surface floats upon a surface of the liquid and is pushed upwardly against a surface of the chamber. The spherical body has a smaller diameter than the diameter of the chamber to define a restriction passage which inhibits the flow of liquid when the switch is subjected to shock.
    Type: Grant
    Filed: June 9, 1992
    Date of Patent: March 30, 1993
    Assignee: Fifth Dimension, Inc.
    Inventor: Sheldon S. Bitko
  • Patent number: 5140303
    Abstract: A liquid level responsive sending unit is positionable in a vehicle fuel tank to deliver a signal to a fuel gage on the vehicle dashboard. An electrical damping circuit is provided on a circuit board carried on the sending unit, such that momentary fluctuations in a fuel level sensor float are smoothed out. The signal transmitted to the gage is a signal representing a time-averaged condition of the sensor. The damping circuit location in the fuel tank is advantageous as regards signal accuracy calibration, manufacturing quality control, ease of assembly, and access for component replacement purposes.
    Type: Grant
    Filed: July 9, 1990
    Date of Patent: August 18, 1992
    Assignee: Carter Automotive Company, Inc.
    Inventor: Paul M. Meyer
  • Patent number: 4967181
    Abstract: A fuel level gauge provided with a remaining-amount warning apparatus is arranged so that an indicating needle for indicating the amount of fuel remaining in a fuel tank operates in accordance with a change in the resistance of a resistor device consisting essentially of a resistance plate having a resistor and a sliding element capable of sliding on the resistor in accordance with a liquid level change in the fuel tank. A warning means for issuing a warning when the amount of remaining fuel reaches a predetermined amount also operates by utilizing the resistor device. In such a fuel level gauge, the warning means is activated by a circuit disposed to connect a remaining-amount warning point and the warning means, the remaining-amount warning point being the position on the resistor at which the sliding element is positioned when the amount of remaining fuel reaches a predetermined amount which requires issuance of a warning.
    Type: Grant
    Filed: September 1, 1989
    Date of Patent: October 30, 1990
    Assignee: Yazaki Corporation
    Inventors: Tsutomu Iizuka, Tatsuo Ikegaya
  • Patent number: 4949070
    Abstract: A lubricant level monitor for gear covers of locomotives uses a vacuum probe tube to determine if the lubricant is below a predetermined level. The vacuum is only activated if the locomotive has been at rest for a predetermined period of time, so that the lubricant has time to settle. The monitor employs a minimal amount of electrical devices and uses pneumatic logic wherever possible insure trouble-free operation. The monitor eliminates the requirement of inspection personnel going beneath the locomotive, and it eliminates the need for the locomotive to be arbitrarily pit-inspected every two weeks for a lubricant level check.
    Type: Grant
    Filed: January 19, 1989
    Date of Patent: August 14, 1990
    Inventor: Donald C. Wetzel
  • Patent number: 4878043
    Abstract: A device for indicating values which are of interest in hydroculture applications is characterized in that the device includes a tube open at one end thereof and attached to a vessel at another end thereof. A probe including a sensor is disposed proximate the one end of the tube for responding to liquid. An IC connected to the sensor includes an electronic system 12 and an optical or acoustic signal transmitter (15) is connected to the electronic system galvanically or in a wireless manner. This arrangement makes it possible to reliably indicate any absence of liquid and to read the indication with ease.
    Type: Grant
    Filed: November 16, 1987
    Date of Patent: October 31, 1989
    Inventors: Guy Heusquin, Anke Heusquin
  • Patent number: 4804947
    Abstract: A water sensing apparatus has a housing and a circuit within the housing. An alarm, e.g. a piezoelectric horn, is driven by the circuit. An elongate sensor is secured to the housing and is connected to the circuit. The other end of the sensor is adapted for sensing the presence of water, to activate the alarm. The sensor is both sufficiently rigid to enable it to maintain a configuration in which the apparatus is hung by the sensor, and is sufficiently flexible to enable it to be bent manually to a desired configuration.
    Type: Grant
    Filed: May 29, 1987
    Date of Patent: February 14, 1989
    Inventor: Rimas J. Geleziunas
  • Patent number: 4638291
    Abstract: An electrically conductive liquid level sensor utilizing a pair of parallel closely spaced electrically conducting probes that are exposed within a liquid container for immersion in said liquid. The sensor includes an electrical insulator partition extending between the probes so as to interrupt any direct path therebetween while at the same time localizing the conduction path to a narrow band of liquid levels due to the close spacing of the probes.
    Type: Grant
    Filed: June 13, 1984
    Date of Patent: January 20, 1987
    Assignee: Ford Motor Company
    Inventor: Boris Puscasu
  • Patent number: 4638305
    Abstract: Diesel fuel tends to deposit an insulating coating on surfaces it contacts. A probe, preferably in the form of a siphon tube, is coupled to a detection circuit which is responsive to either low resistance or high capacitance between the probe and ground. The probe is initially uncoated to make a resistive coupling to a fuel container when accumulated water touches the probe. When insulating deposits from the diesel fuel or other fuel oil coat the probe, capacitive coupling will occur between the probe and the accumulated water. In either case the presence of water triggers an output signal by the detection circuit.
    Type: Grant
    Filed: March 22, 1985
    Date of Patent: January 20, 1987
    Assignee: General Motors Corporation
    Inventor: Stephen J. Sutton
  • Patent number: 4575597
    Abstract: A position responsive switch apparatus comprising a housing and a mounting assembly secured within the housing. The mounting assembly includes a pair of oppositely disposed spaced-apart walls. Each of the walls has an aperture contained therein which are in general axial alignment. An elongate switch extends through the apertures and is transversely supported by the mounting assembly so that the switch may move in a generally longitudinally axial direction within the confines of the mounting assembly. The switch may be in one of two preselectd conditions. The switch moves from one condition to the other condition in response to an opposing directional displacement of the switch. A retaining element is carried on the switch intermediate of the apertures. The retaining element is of a greater dimension than the apertures so that the walls moveably retain the switch within the mounting assembly.
    Type: Grant
    Filed: August 3, 1984
    Date of Patent: March 11, 1986
    Assignee: The Scott & Fetzer Company
    Inventor: Pervez Akhter
  • Patent number: 4572934
    Abstract: The present invention relates to a mercury switch (10) including an outer metal housing (12) having a closed end and an open end. A baffle member (14) is positioned in the housing (12) immediate of the closed and open ends. The baffle member (14) defines a first bore (32), a second bore (34) of increasing diameter in a direction toward the open end of the housing (12), and a third bore (36). An electrode assembly (16) is partially inserted into the open end of the housing (12). The electrode assembly includes a solid electrode (40) having a stem portion (42) and a head portion (44) with a truncated conical configuration of decreasing diameter in a direction toward the closed end of the housing (12) and having a recessed surface 102 providing a mercury wetting reservoir. The baffle member (14) and the truncated conical head portion (44) cooperate to provide contact between a first supply of mercury (30a) and the solid electrode (40) at a location removed from an insulating member (46).
    Type: Grant
    Filed: July 20, 1984
    Date of Patent: February 25, 1986
    Assignee: S. J. Electro Systems, Inc.
    Inventor: Stephen P. Johnston
  • Patent number: 4529854
    Abstract: The present invention relates to a mercury switch (10) including an outer metal housing (12) having a closed end and an open end. A baffle member (14) is positioned in the housing (12) immediate of the closed and open ends. The baffle member (14) defines a first bore (32), a second bore (34) of increasing diameter in a direction toward the open end of the housing (12), and a third bore (36). An electrode assembly (16) is partially inserted into the open end of the housing (12). The electrode assembly includes a solid electrode (40) having a stem portion (42) and a head portion (44) with a truncated conical configuration of decreasing diameter in a direction toward the closed end of the housing (12). The baffle member (14) and the truncated conical head portion (44) cooperate to provide contact between a first supply of mercury (30a) and the solid electrode (40) at a location removed from an insulating member ( 46).
    Type: Grant
    Filed: March 30, 1984
    Date of Patent: July 16, 1985
    Assignee: S. J. Electro Systems Inc.
    Inventor: Stephen P. Johnston
  • Patent number: 4316239
    Abstract: A trunk lid lamp assembly comprising a housing having a first generally tubular part having open ends and a second generally tubular part having a closed end wall with interengaging means which provide a snap fit between said parts. The first part has an axially extending slot into which an offset portion of a bracket extends. The bracket has an L-shaped bayonet slot therein which is exposed to the interior of the first part whereby it may receive the lug of a lamp bulb and hold the bulb in position in the first part. The second part has a portion engaging the bracket to hold the bracket in position in the slot of the first part. The second part also has an axially extending opening in the end wall thereof adjacent the periphery thereof and a terminal extends into the opening and is frictionally held in position. The terminal has a first contact portion.
    Type: Grant
    Filed: July 16, 1979
    Date of Patent: February 16, 1982
    Assignee: Beta Manufacturing Corp.
    Inventors: Louis G. Cass, Nicholas Poleschuk, Samuel Purdy
  • Patent number: 4087706
    Abstract: The present application presents a setup utilizing a float in an enclosed space as a bridging contact, on the basis of the liquid level in the area to control, to activate a semiconductor relay having a time delay for such activation, and is especially valuable where the liquid level involved is that of a non-conductive liquid under severe conditions.
    Type: Grant
    Filed: November 24, 1975
    Date of Patent: May 2, 1978
    Assignee: Hynes Electric Heating Company
    Inventor: George L. Koester, Jr.
  • Patent number: 3939470
    Abstract: An improved liquid level detecting and indicating system for vehicles comprising a pair of liquid level detecting elements which are arranged in opposite positions on the detecting level of a liquid in a liquid container installed in a vehicle, whereby when each of the liquid level detecting elements sends a signal indicating that the liquid level has dropped below a reference liquid level, an indicator is brought into operation. In this way, the level of liquid can be accurately detected and indicated without being influenced by the inclination or vibration of a vehicle body.
    Type: Grant
    Filed: February 5, 1974
    Date of Patent: February 17, 1976
    Assignees: Nippondenso Co., Ltd., Toyota Jidosha Kogyo Kabushiki Kaisha
    Inventors: Hiroshi Arai, Jun Ohta, Koichi Taniguchi, Yasuhiko Sakurai, Toshikazu Ohtake