Abstract: The electronic interface circuit can perform ratiometric processing and driving of a signal generated by a fuel-level detector of a vehicle. The circuit uses a current mirror configured so as to send one half of the output current to the input resistance and one half of the output current to earth. The current mirror is controlled by a voltage taken from the input resistance and by a voltage taken from a resistive divider, the latter voltage having been filtered by a low-pass filter, so as to achieve ratiometric processing of the input signal.

Abstract: A modular overfill alarm assembly is constructed and arranged to be installed in-line with a vent pipe in a vented storage tank for liquids such as waste oil or gasoline. The alarm assembly includes a vent tube having an open lower end that is threaded to be mounted to a vent opening in a vented storage tank, and an open upper end that is threaded to have a vent pipe mounted thereto, so that the vent pipe may be communicated with the vent opening as it would if it were threaded directly into the opening. The assembly further includes a support bracket mounted to the vent pipe and vent tube for supporting a commercially available alarm for actuating the alarm.

Abstract: Improved apparatus and methods for forming a layer of material over a surface of a previously-formed cross-section of a three-dimensional object in anticipation of forming a next cross-section of the object out of the layer. A volume of material, including at least some excess material, is placed over the surface, and the excess material is swept off by placing the excess material in the predetermined path of a sweeping member, the path being substantially in a plane spaced from a working surface of material. The member may be directed to sweep the excess material away through a successive number of sweeps, which may vary for each cross-section, at least a velocity which may vary for each sweep. Additionally, the clearance between the member and the surface of the previous cross-section may vary for each sweep. A "winged" member is also provided, comprising two legs extending from a base, and a "Trident" embodiment is also provided, comprising three legs extending from a base.

Abstract: A water appliance detection and cut off apparatus is provided including a water entry conduit for receiving water from a water source. A pan is provided having a bottom face and a lip coupled thereto and extending upwardly therefrom for defining an open top and an interior space into which the water appliance is stored. A water ball valve is connected to the water entry conduit. In use, the ball valve has a closed orientation upon at least the instantaneous receipt of an activation signal wherein water is prevented from flowing to the water appliance and an open orientation upon at least the instantaneous receipt of a deactivation signal wherein water is allowed to flow to the water appliance.

Abstract: A universal read head for a tank-level float gauge is adapted for use with any of certain different types of gauge rods which may be connected to a float element in the tank, including rods having an optical code thereon including a plurality of alternating reflecting and non-reflecting stripes arranged between magnetic end portions, and a rod with one or more magnets disposed adjacent to each end thereof and longitudinally spaced magnets intermediate the ends. The sensing head includes an LED light source for illuminating the rod and two phototransistors coupled in quadrature relationship for detecting the illuminated optical code patterns, and two magnetic reed switches for sensing the proximity of magnets on the gauge rod. The sensors are coupled to a microprocessor for interpreting the electrical signals generated by the sensors to identify the type of gauge rod being used and to provide an indication of the position of the gauge rod relative to the sensors.

Abstract: A device for sensing the amount of oil in oil pans of internal combustion engines is disclosed. In the device, a bottom plunger is fixedly mounted onto the inside bottom of an oil pan, with a contact terminal being mounted onto the top surface of the bottom plunger. A top plunger is movably positioned above the bottom plunger, with a contact terminal being mounted onto the bottom surface of the top plunger. The two contact terminals are normally spaced apart from each other in the event of the amount of oil being not less than a preferred amount. However, the two terminals are selectively brought into contact with each other in the event of an oil shortage in the oil pan. The device also has a means for selectively generating an alarm signal under the control of an ECU in the event of the two terminals being brought into contact with each other.

Abstract: A new HOT WATER HEATER LEAK PROTECTION SYSTEM for PREVENTING OVERFLOW OF HOT WATER IN IF A HOT WATER HEATER BREAKS. The inventive device includes an overflow tank having a cylindrical stand positioned centrally thereon for positioning a hot water heater thereon. The overflow tank has a supplemental housing secured therein. The supplemental housing has an opening in a lower portion thereof to allow water to flow therethrough. An automatic float switch is positioned within the supplemental housing. A pump is disposed within the supplemental housing. The pump is in communication with the automatic float switch. A shut off valve is disposed within a housing coupled to a water line leading into the hot water heater. The shut off valve is in communication with the pump and the automatic float switch.

Abstract: A liquid level detector utilizing a housing having a wall portion defining a inner chamber. The inner chamber communicates to the exterior of the housing through an opening which also permits liquid to enter the chamber. A floatation element is pivotally located within the housing and includes a bridging conductor which rotates upwardly. The bridging conductor is capable of contacting a pair of terminals which constitute a portion of an alarm circuit.

Abstract: An alarm system to warn those pumping fuel into remote tanks that the fuel level is at the top of the tank, and thus prevent overflowing. This system is particularly useful for filling tanks in boats.

Abstract: A pipeline leak detection apparatus is provided for fluid dispensing system having a dispenser, a storage tank, and a pump and an electric cut-off valve arranged in hydraulic series with the outlet of the storage tank. The pipeline to be monitored extends between the cut-off valve and the dispenser. A control circuit that operates the cut-off valve such that the valve opens with use of the dispenser and closes with non-use in order to hydraulically isolate the storage tank and pump from the pipeline and dispenser during periods of non-use. The leak detection apparatus is connected in a by-pass loop around the pump. It includes a small pot or plenum, a float switch, and a return line for fuel to spill back into the storage tank. The plenum inlet is connected to a branch in the pipeline near the cut-off valve, and its outlet is connected to the return line to the storage tank. The float switch is mounted to the plenum so that its float extends into the plenum chamber.

Abstract: A liquid gauging system for a liquid container, the system comprising sensor means for producing a first electromagnetic signal that corresponds to liquid quantity in the container, and remote interrogation means for receiving the first electromagnetic signal and producing a system output that corresponds to the liquid quantity; the sensor means being energized by a second electromagnetic signal transmitted by the remote interrogation means.

Abstract: The present invention is a water level detector or flood alarm device which will activate a warning once water has reached a pre-determined and potentially damaging or dangerous level. The present invention comprises a housing which maintains a conventional mercury activated float switch, an alarm coupled to the switch, a mounting device, and an attaching mechanism. The mounting device maintains the housing and includes a pivotal mechanism for enabling the housing to pivot and rotate. This pivoting and rotation will allow the housing to be angularly positioned, with respect to the ground, so that the float switch will be positioned horizontally and parallel with respect to the water. The attaching mechanism enables the device to be removably secured to any surface and to be maintained in a secured and installed position.

Abstract: A device and method for sensing fluid characteristics, including level, temperature, pH and chemistry, comprises a switch affixed to or embedded in a container of a size, shape and density such that said container floats stably in said liquid until a predetermined level is reached; the container tilts so as to operate the switch when the liquid drops below or increases above a predetermined level. The device may contain additional sensors which measure and report other characteristics of the liquid, such as temperature, pH, viscosity, chemistry or biochemistry.

Abstract: The present invention relates to a wireless remote fuel gauge (10) comprising a tank gauge (12) positioned on a fuel tank (16A, 16B). The tank gauge (12) comprises a tank gauge microprocessor/analog converter (12A) electrically connected to a tank gauge power line (12F). A tank gauge transmitter (12B) is electrically connected to the tank gauge microprocessor/analog converter (12A). The tank gauge transmitter (12B) functions to transmit, by radio frequency, a level of fuel (18) information within the fuel tank (16A, 16B). A tank gauge indicator (12D) is mechanically connected to the tank gauge microprocessor/analog converter (12A). The tank gauge indicator (12D) functions to allow a consumer to visually monitor the level of fuel (18) within the fuel tank (16A, 16B). The tank gauge float (12G) maintains position on the level of fuel (18) within the fuel tank (16A, 16B).

Abstract: Abnormal flow of liquid in a non-pressurized conduit such as a drain line of a building is detected by a liquid level sensor unit connected at a conduit location not anticipated to fill with liquid during normal flow, so that liquid backing up at such location will enter a sensor chamber of the unit to cause a liquid level sensor to signal an indicator. A monitoring system uses at least one such sensor to signal at least one local or remote indicator that indicates which sensor has detected abnormal flow. The system can monitor for short times particular drain lines suspected of experiencing abnormal flow, or can serve on a long-term basis to provide an early warning of clogging and blockage in lines selected for monitoring.

Abstract: Disclosure is made in this application of a pedestal housing and a pedestal control housing segment mounted at the top of the pedestal housing and a control panel board mounted in the control housing segment and power lines entering the pedestal housing below the ground level and into the pedestal housing and lead connectors extending from sump pump and sump pump float switch and tank alert float switch extending from sump tank through a connector duct or pipe into the pedestal housing and extending to the control panel board in the housing segment and a door mounted on the control housing segment to seal the control housing segment. The lead connectors of the power lines and the float switches extend through apertures in the bottom of the control housing segment and are held in position by grommets to seal the openings around the lead connections.

Abstract: A tracking buoy including a sensor to detect the presence of hydrocarbons in a body of water and a communication system to transmit data to a remote monitoring center when the hydrocarbons are detected to indicate the direction and speed of travel of the hydrocarbons in the body of water.

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.

Abstract: A device for warning when a low fluid level is reached is provided in which a levelness detecting switch is encapsulated in a conically shaped inert material (such as TEFLON.TM.), sized appropriately to the predetermined fluid limit, and coupled to an alarm device (such as an audible alarm, a frequency signal or a light).

Abstract: Disclosed is a device used to verify the identity of a selected fluid before permitting the selected fluid to be introduced into a storage vessel containing a liquid of known specific gravity. The device includes a container constructed from connecting walls to form a chamber having an opening through which a selected fluid may be introduced; a first float switch positioned in the container for generating a first signal when contacted by a fluid having a specific gravity greater than a first predetermined amount; a second float switch positioned in the container for generating a second signal in the presence of a fluid having a specific gravity greater than a second predetermined amount, where the first predetermined amount is less than the second predetermined amount, and the second float switch is responsive to the first signal from the first float switch.

Abstract: A remote level sensor for a residential fuel oil tank is adapted for a fuel oil gauge with a permanent magnet which changes position with changing fluid levels in the tank. The sensor has a housing with a connector which receives a top portion of the gauge such as to provide an alignment of the sensor with the gauge. The sensor is connected to a telephone line, and makes use of a current from the "tip" and "ring" lines of the telephone connection to supplement the power of an on-board battery. The sensor has multiple reed switches each in a different relative position. The reed switches thus each close when the magnet is in a different position, and thereby close when the fluid in the tank is at a different level. The controller has a sampling routine which responds to the detection of a closure of one of the switches by seizing the telephone line, dialing a central monitoring location and transmitting information to the central location indicating which of the switches was closed.

Abstract: A liquid level alarm system which activates an alarm when liquid in a container falls below a predetermined level. The system contains an alarm which is located outside of the container. The alarm is electrically connected to an activation device which is contained within a housing. A single-pull switch arm is connected to the activation device and protrudes from the housing. One end of a line is attached to the distal end of the arm. The other end of the line is wound about a spring reel mounted on an axle connected to a float. When the surface of the liquid is between a predetermined upper and lower level, the spring reel maintains the line taut directly below the switch arm. The line is of such length that should the liquid in the container drop below a predetermined level, the float will no longer be supported by the liquid, and the weight of the float will pull the arm down to activate the alarm.

Abstract: An optical tank-level gauge includes an elongated gauge rod magnetically coupled at its lower end to a float for rising and falling with the liquid level. The outer surface of the rod is provided along most of its length with alternating reflecting and non-reflecting circumferential stripes of equal height, the rod having non-reflecting zones at its opposite ends. An optical read head is fixed on the tank and includes LEDs for illuminating the rod and four optical sensors spaced apart longitudinally along the rod and arranged into quadrature pairs relative to the stripes, so that each pair reads a longitudinal extent of the rod substantially equal to the height of one stripe. Each of the non-reflecting end zones has a height such that, in either the full or empty condition, the fields of view of all four optical sensors will be completely within one or the other of the end zones.

Abstract: A system is provided for producing a three dimensional object from a reactive liquid medium capable of being solidified. The object is constructed from many successive layers of the solidified reactive liquid medium when subjected to appropriate synergistic stimulation. A reservoir contains both the reactive liquid medium and an underlying supporting, substantially immiscible, non-reactive liquid medium. To begin forming the object, a platform within the reservoir is initially positioned at a depth equal to the thickness of a first layer to be solidified, and continues to support the object being constructed. The synergistic source radiates toward the reactive liquid medium and imaging apparatus defining a three dimensional object of required configuration selectively controls the size and shape of that part of a new two dimensional layer to be solidified. At least part of the new layer is solidified, after which a further layer is applied.

Abstract: A system for generating three-dimensional objects by creating a cross-sectional pattern of the object to be formed at a selected surface of a fluid medium capable of altering its physical state in response to appropriate synergistic stimulation by impinging radiation, particle bombardment or chemical reaction, successive adjacent laminae, representing corresponding successive adjacent cross-sections of the object, being automatically formed and integrated together to provide a step-wise laminar buildup of the desired object, whereby a three-dimensional object is formed and drawn from a substantially planar surface of the fluid medium during the forming process.

Abstract: Signal generating apparatus comprises a linear series of Hall-effect switches (44) arranged as a plurality of linear arrays in discrete probes (46a, 46b . . . 46n) which are butted end to end. Each switch is closed when in proximity of an actuating magnet (40) moveable along the series of switches. In each array a resistance chain (66) is linked at intervals to the switches. Movement of the magnet along an array thereby gives a progressively changing voltage on an output line (50) from the resistance chain as a cumulative signal indicating the position of the magnet. When the magnet moves from one array to the succeeding array after generating a maximum cumulative signal from said one array, that signal is maintained by a latch connection (56) between the two arrays. A cumulative signal representing the magnet position relative to the complete series of switches can thus be generated.

Abstract: A magnetically activated float switch apparatus is disclosed for opening and closing an electrical circuit in response to a predetermined change in the level of a liquid. The apparatus includes a float element having an interior chamber. There is a capsule mounted within the chamber. A permanent magnet is mounted in the capsule and is slidable between first and second positions therein. A switch is mounted in the chamber adjacent to the capsule and is electrically connected to the electrical circuit. The switch is responsive to the permanent magnet in the first position for maintaining a first state and is responsive to a permanent magnet in the second position for maintaining an opposite second state. One of the states is open and the other is closed. The float element is suspended by a cable in an upright condition when the liquid is below a known level such that the magnet is in the first position and the switch is in the first state.

Abstract: An oil spill detection system to detect and track oil spills and transmit data to a remote monitoring center comprising a buoyant detection platform including at least one detection sensor to detect the presence of hydrocarbons in the water adjacent the buoyant detection platform and generate a detection signal in response thereto and a communication system operatively coupled to the detection sensor to receive the detection signal and to generate a data signal in response to the detection signal and to transmit the data signal to the remote monitoring center, the data signal including a discrete platform identification signal corresponding to the buoyant detection platform, and a deployable free floating tracking buoy to be deployed when the detection signal is generated to indicate the direction and speed of travel of the oil slick created by the oil spill.

Abstract: The fuel tank of a mobile vehicle is provided with a level sensor for sensing the level of fuel in the tank as it is being filled. The output signal from the level sensor is applied to a microprocessor which in turn provides output signals to drive an audible alarm and a visual display. The microprocessor determines the level of fuel in the tank from the signal produced by the level sensor and drives the audible alarm to provide a first sound pattern, such short beeps or tones when the tank is at least 3/4 full but less than 7/8 full and a second sound pattern such as a continuous tone when the tank is at least 7/8 full. The microprocessor also drives a visual display to display text messages indicating the level of fuel in the tank. A vehicle operator may initiate filling of the tank and attend to other service on the vehicle, leaving the fill operation unattended. The first sound pattern warns the operator that he must soon give his full attention to the fill operation.

Abstract: A device is disclosed for sensing any of a wide range of liquid hydrocarbons. A ribbon-like sensor is employed, which has an inner, silicone rubber layer and an outer, silicone rubber layer and which has two broad faces and two narrow edges. The silicone rubber layers are capable of absorbing and swelling in the presence of a liquid hydrocarbon. The inner layer but not the outer layer is filled with electrically conductive particles, preferably carbon black particles, so as to be capable of switching from having an electrical impedance which is relatively low to having an electrical impedance which is relatively high when swollen in the presence of a liquid hydrocarbon. As made from an open cell, polyethylene foam, a porous body is attached to the sensor. The porous body is capable of floating with the sensor on water or on a liquid hydrocarbon and of conducting a liquid hydrocarbon through the porous body to the sensor.

Abstract: A liquid level controller comprises of a control circuit, a control box, a sump pump, and a liquid level indicating means, the liquid level indicating means comprising a high level indicating device and an impulse indicating device, the high level indicating device and the impulse indicating device comprising pipe bodies, magnetic switches, floating element or impulse element. The pipe body of the impulse indicating device has a connecting pipe connected to the side thereof. The magnetic switches located on the top of the pipe bodies and connected to the control circuit with electric wires. When the liquid surface raises and buoys the floating element of the high level indicating device to contact the magnetic switch, the magnetic switch produces a signal to the control circuit and the sump pump is started to draw the liquid out of the tank.

Abstract: A security apparatus is used in a kitchen or a bathroom for detecting the gas leakage and controlling the water temperature and water level in a bathtub or a container. This apparatus is capable of detecting the gas leakage and monitoring the water temperature and level in a container or a bathtub via three relays. The security apparatus further provides an emergency lamp circuit for illumination and a radio circuit for user(s) to listen to a radio program when the users are in a kitchen or a bathroom. The radio program may be replaced with an alarm when a gas leakage occurs, water temperature is too hot or the container or the bathtub is full.

Abstract: An apparatus for detecting a liquid level includes a warning device for warning a low liquid level, and a regulator for controlling power supply to the warning device from a power source. The regulator comprises a switch for switching its condition in accordance with the liquid level. The ON condition of the switch indicates that the present liquid level is lower than a predetermined liquid level. The regulator further comprises a thermistor connected to the switch in series. The thermistor has a characteristic of decreasing the resistance value thereof, when a predetermined delay period of time as a function of atmospheric temperature has elapsed since the start of applying the voltage on the thermistor, synchronizing with turning the switch on. The low resistance value of the thermistor allows the power for activating the warning device to be supplied to its device, while the switch is turned on.

Abstract: A leak detection and management apparatus including a programmable message device, for a hot water heater. The apparatus includes a liquid pan disposed beneath and concentrically with a hot water heater for collecting water leaking from the hot water heater. A float is disposed at least partially within the liquid pan 14 and causes an electrical shut-off signal from an electrical switch to be generated when it is elevated in response to the collection of water within the liquid pan 14. The electrical shut-off signal causes electrically controlled solenoid valves disposed in the water supply and gas lines to the hot water heater 12 to be closed, thereby interrupting the flow of cold water and natural gas into the hot water heater 12, and simultaneously causing a programmable message device to play a prerecorded message informing of the water leak and where to obtain service to correct same.

Abstract: A funnel body includes an exit tube, wherein a mesh web pocket is arranged for securement to a lowermost end of the exit tube secured to an annular groove, with the pocket including a buoyant sphere arranged for projection into the exit tube exit opening for curtailing fluid flow therethrough.

Abstract: A float-operated switch assembly is mounted in an opening in the top of a tank. It includes a vertical non-magnetic pipe having a pair of floats normally hanging beside it. Each of the floats has a magnet thereon normally in a position proximate the pipe when the float is down. A magnetic field between this magnet and a switch operator support magnet inside the pipe normally holds the latter magnet in a set position. The floats are located at a height such that, when the liquid has risen to the desired upper limit, the rising liquid has caused the floats to swing up and outward from the pipe, pulling their respective magnets out of supporting relationship to the switch operator support magnet whereupon the support magnet drops and a switch is operated for activating a signal circuit. A manual test knob is provided to remotely, manually lift the floats.

Abstract: A flood warning system including a stilling well having three vertically spaced apart float switches therein for detecting the level of flood waters. Upon the water level reaching and closing the lowest float switch, a telephone alarm dialer is actuated to transmit a first low stage flood warning message to a remote location. Upon the water level reaching and closing the second or middle level float switch, the lowest float switch is disabled and the upper float switch is enabled. Upon the water reaching and closing the upper float switch the telephone alarm dialer is actuated to transmit a high stage flood warning message to the remote location. As the water recedes, upon dropping below and opening the middle level float switch the lowest float switch is enabled and the upper float switch is disabled thereby actuating the telephone alarm dialer to transmit a second low stage flood warning message to the remote location. This second low stage flood warning message indicates that the flood has crested.

Abstract: Method and apparatus for detecting and/or monitoring the presence of hydrocarbons in a fluid medium at a remote location, by sensing the presence of hydrocarbon-based fluid in the fluid medium in the remote location, generating a signal indicative of the sensed fluid, and transmitting the signal to monitoring means for indication of hydrocarbon contamination. The apparatus has multiple sensors at different vertical levels for sensing the fluid medium at a plurality of levels within the fluid.

Abstract: Improved apparatus and methods for forming a layer of material over a surface of a previously-formed cross-section of a three-dimensional object in anticipation of forming a next cross-section of the object out of the layer. A volume of material, including at least some excess material, is placed over the surface, and the excess material is swept off by placing the excess material in the predetermined path of a sweeping member, the path being substantially in a plane spaced from a working surface of material. The member may be directed to sweep the excess material away through a successive number of sweeps, which may vary for each cross-section, at least a velocity which may vary for each sweep. Additionally, the clearance between the member and the surface of the previous cross-section may vary for each sweep. A "winged" member is also provided, comprising two legs extending from a base, and a "Trident" embodiment is also provided, comprising three legs extending from a base.

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.

Abstract: A stereolithographic system for automatically generating three-dimensional objects on a layer by layer basis by alternately forming layers of medium over previously formed layers of the object and selectively solidifying successive layers of medium at a surface of a body of the medium whereby the object is formed from a plurality of solidified and adhered layers. The surface of the body of medium is maintained at a desired working surface, for example by detecting its level and relatively adjusting it and the working surface so that they coincide.

Abstract: A fail-safe system for the detection of water leaks, and for the prevention of damage therefrom. In a home or building which includes a hot-water tank and a water tank for a toilet, e.g., the damage-prevention system comprises valves for shutting off the supply of water to the tanks, and other valves for draining the tanks through discharge lines to the outside of the home or building. At the same time, power to the hot-water tank is shut off. A fail-safe water detector comprises a float with a metal cap, a first pair of electrical probes below the float, and a second pair of electrical probes above the metal cap and separated from the cap by an air gap. A circuit is closed in any of three ways: (1) when water contacts the first pair of probes, (2) when water raises the float and makes contact between the metal cap and the second pair of probes, and (3) when water contacts the second pair of probes.

Abstract: A refrigerant loss detector and alarm, the detector device suitable for installation in the piping of a refrigeration system which utilizes a liquid/vapor phase change substance as the refrigerant. Upon detection of refrigerant vapor accumulating in the loss detector, thereby displacing refrigerant liquid therefrom, the orientation of a float element containing a mercury switch is affected. Upon a fall in refrigerant liquid level in the loss detector, the mercury switch becomes activated, thereby completing an external electrical circuit which contains a time delay device and an alarm device.

Abstract: A centrally controlled system for preventing overflow of fuels during loading operations includes dual processors either of which can take over the functions of the other processor when it fails. The system also includes full self-diagnostics and automatic testing to ensure that the warning lights and audible alarms at the loading compartments and the warning lights and audible alarms at the central location are operative during loading operations. If warning lights at the loading compartments are not visible due to obstructions, a voice synthesizer is used instead of lights at the loading compartments to announce the compartment identifier and the level of alarm reached. Floats in each compartment operate contacts when the level in the compartment reaches a first high level and when the level in the compartment reaches a second overfill level. In addition, if the level in any compartment reaches an overfill level, the power to the pumping station is automatically cut-off ceasing the loading operation.

Abstract: Apparatus and methods for stereolithographically forming a three-dimensional object includes a vessel for holding a building material and a smoothing member for forming a uniform coating over a previously formed layer of the object. The smoothing member has a plurality of blades. The smoothing member is swept over a previously formed layer of the object, in at least two directions. Different clearances between the lower surface of the smoothing member and the upper surface of the previously formed layer are used to provide a uniform coating for a subsequent layer over the previously formed layer. The sweeping velocity of the smoothing member can be varied. Retractable needles are attached to the smoothing member for adjusting a blade gap between the lower surface of the smoothing member and the surface of the building material.

Abstract: Galvanic corrosion of the fuel sender immersed in the corrosive fuel mixture is minimized by supplying the sender with current that periodically switches polarity. The switching rate is selected to prevent or greatly minimize irreversible oxidation buildup. The vehicle body computer responds to current flow through the sender without regard to the alternating polarity drive signal. The switched polarity sender module can thus be employed without necessitating modification of the sender or body computer components.

Abstract: A material level sensing device for detecting when the level of unprocessed material has reached a predetermined threshold includes a contact-type probe extending from a housing into a retaining bowl where unprocessed material is collected before processing. Within the housing is disposed a proximity sensor. The housing itself is suspended from an overhanging support. When the material level reaches the predetermined threshold, the material displaces the material level sensor, which displacement is sensed by the proximity sensor. The proximity sensor then sends a signal to an external system indicating that the material has reached the threshold.

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.

Abstract: The gauge has an outer tube sealed at its lower end and adapted for attachment to the top wall of the tank, and an inner tube axially movable within the outer tube. A float encircles the outer tube and moves freely therealong. First and second magnets respectively attached to the float and to the lower end of the inner tube provide magnetic coupling therebetween so that a rising liquid causes the inner tube to rise with the float. Magnets within the inner tube operate a switch to signal when the first and second magnets are in position for magnetic coupling therebetween. Another magnet is fixed by a set screw to the outside of the inner tube in position for operating the switch when the tank is substantially full. Retaining clips are also disclosed for holding the latter magnet in place.

Abstract: The invention is an electronic sensor for producing an indication of fluid level in a hose or tube and an electronic indicating circuit that uses the sensor's indication of fluid level for asserting one of three indicators depending upon whether the fluid level is above a reference by a small distance, within the small distance of the reference, or below the reference by the small distance. A float retaining a core having a relative magnetic permeability significantly greater than one is supported by fluid near three vertically disposed coils. The center coil is excited by a source of alternating current and the position of the core above or below the center coil determines the voltages present in the top and bottom coil. The voltages present in the top and bottom coils are rectified and added in polarity opposition to produce an indication of fluid level. A plurality of voltage comparators, supplied by the indication of fluid level and fixed voltages, are used to assert the appropriate indicator.