Abstract: A method and apparatus for measuring low fuel level in a fuel tank having a fuel pump with an anti-slosh pot supplied with fuel from a predelivery pump in the fuel pump. Fuel measurement is effected by sensing delivery of air to the anti-slosh put by the predelivery pump when the fuel level in the tank is low, and measuring the amount of fuel in the anti-slosh pot when delivery of air is sensed. The amount of fuel measured in the anti-slosh pot accurately represents the amount of fuel remaining in the fuel tank.

Abstract: A digital position transmitter is disclosed which uses a fixed array of physicoelectric proximity switches to locate a physical exciter and transmit the position of the exciter as a hexadecimal coded number or as a string of pulses. The position transmitter uses solid state components, has no moving parts and requires less power than any one proximity operated alone. The transmitter attains moderate resolution while displaying excellent accuracy and precision. The transmitter is completely non-intrusive; there is no contact between the physical exciter and the switch array, making the transmitter particularly suited for determining the position of objects that must be completely isolated because of pressure, temperature, of chemical hazards. Further circuits are described for converting the inherently digital output signal to industrial standard 4-20 mA or voltage signals.

Abstract: This invention concerns a water alarm adapted to be mounted in a basement water drain. It comprises a buoyant body which is in a first position when water is absent from the drain and which is moved to a second position by the presence of sufficient water filling the drain pipe. The buoyant body carries a switch which is in an open position when the body is in its first position and which is in a closed position when the body is in its second position. A suitable alarm is activated when the switch is in its closed position. The buoyant body is held in position adjacent the upper end of the drain under the metal drain cover by a magnetic holder member.

Abstract: A vehicle anti-freeze monitor for monitoring the capability of the vehicle's coolant mixture in the cooling system of the vehicle to resist freezing. The monitor includes a light emitting diode, a reed switch for coupling the indicator to a source of electricity and for selectively activating and deactivating the indicator. Also included is a float for submersion into the vehicle's coolant mixture. The float includes a buoyant body and a magnet which activates the reed switch when the vehicle's coolant mixture is in a safe condition against freezing and deactivates the reed switch when the coolant mixture is in an unsafe freezable condition.

Abstract: A drain overflow alarm for a washing machine drain, which alarm is mounted in a vertical drain line offset provided with a check valve and extending from the vertical fixed drain line or standpipe of a structure. In a preferred embodiment the alarm includes a float switch located in the top end of the drain line offset and a transformer, relay, alarm and optical reset button, all provided in a control housing. The float switch is electrically connected to the transformer, relay and alarm, such that obstruction of the fixed drain line causes water to rise in the fixed drain line and through the check valve into the drain line offset. The rising water raises the float element of the float switch and closes the switch to activate the transformer relay and alarm, as well as terminate operation of the washing machine.

Abstract: A float switch includes a buoyant housing defining a non-linear guide path. Switch operating means is located displaceably under gravity within the guide path. The switch operating means is operable to activate switch means in at least one position along its path when the housing is tilted.

Abstract: An apparatus for providing a signal to indicate liquid level above a pre-determined level in a container. The apparatus includes a device for defining a fixed reference level. An alarm unit having an alarm and an alarm actuator is connected to the defining device. A float is connected to the alarm unit and rests on the surface of the liquid. The float actuates the alarm actuator to activate the alarm when the surface of the liquid reaches the pre-determined level.

Abstract: An alarm system is disclosed for use with a water softener including a salt-brine tank containing a bed of salt. The alarm system includes a sensor situated in the salt-brine tank on the top of the bed of salt, an electronic circuit including an alarm, and an input for connecting the circuit to the sensor. The sensor is responsive to direct contact with the brine for operating the circuit to initiate the alarm in the event the top of the bed of salt drops below a preselected level or the brine rises above another preselected level.

Abstract: A self-contained, portable flood alarm is installed at a prospective flood site by merely placing the flood alarm on a flood-prone surface at the site and activates an alarm signal in response to the occurrence of a flood condition on the flood-prone surface as a result of the flotation of a buoyant element of the flood alarm, the buoyant element being capable of floating the entire flood alarm so that the alarm signal will commence immediately upon the onset of the flood condition and will continue independent of the height of the crest of the flood condition.

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.

Abstract: In a device for monitoring the liquid level in a tank, utilizing a reed switch projecting into the tank in an internally cylindrical hollow rod and a float provided with a permanent magnet and guided on the hollow rod, the reed switch is constructed as an independent exchangeable part introducible into the hollow rod with an accurate fit and with a small assembly outlay. The slide-in part has three radially resilient abutment zones distributed uniformly around the circumference. In order to accurately introduce the slide-in part into the hollow rod, with a minimum of force, three axial guide grooves associated with the resilient abutment zones are formed radially outwards in the inner envelope surface of the hollow rod. In order to achieve the final accurate fit, the slide-in part, introduced completely into the hollow rod, is rotated until the resilient abutment zones are located in regions between the guide grooves of the hollow rod.

Abstract: A sewer alarm is provided for warning of overflow conditions in a house trap installed in a sewer line, the sensing mechanism consisting of a magnetic float switch with no moving parts other than the float itself and with the magnetic activating switch sealed from the hostile environment found in a house trap. The alarm cap member housing the magnetic float switch has physical dimensions similar to a typical cap installed in an unalarmed house trap and substantially has only wires protruding from its exterior face.

Abstract: A modular water distillation apparatus includes a distillation unit which may be manually operated by adding water manually to the steam generator. The apparatus further includes an add-on holding tank and an add-on control unit which mounts to the holding tank and provides automatic control of the distillation unit by providing feedwater to the steam generator when the steam generator is deenergized and the holding tank is not full. The add-on control further includes a power receptacle for an add-on distilled water demand pump.

Abstract: A remote oil tank display apparatus is set forth in combination with an oil tank for the indication of oil tank volume. The sending unit is encased in a hermetically sealed container to prevent oil fume propagation throughout an area. A combination digital and light emitting diode display is set forth and is remotely positioned relative to the oil tank to enable individuals of diminished physical capacity to receive and display information of oil volume remaining in an oil tank. Further, an audio means may be selectively employed in concert with the visual displays to assist individuals of diminished hearing capacity.

Abstract: A water level and temperature detector alarm device and more particularly to an alarm device which includes a buoy type detector to alternately detect water level or water temperature so as to provide an audio alarm signal through a buzzer when water level or water temperature reaches the predetermined range. The detector is connected to the expansible end of a conduit and includes a sleeve having set therein two reed switches and a thermswitch and having mounted thereon a body which includes therein a circular magnet. An alarm device is connected to the other end of the conduit which is having a movable positioning rack mounted thereon for positioning of the whole assembly. Following the rising of water level, the magnet of the buoy alternatively drives the reed switched to turn on the alarm device to buzz or, when water temperature reaches the predetermined range, the thermoswitch will be turned on to drive the alarm device to buzz.

Abstract: An elongated hollow body is provided with a mid-length transverse partition and one end of the body is mountable from a sewer pipe in lieu of a cleanout plug thereof and contains a buoyant mercury switch tethered to the partition through the utilization of thin, flexible and relatively insulated conductors passing through the partition in fluid tight sealed engagement therewith and electrically connected to spaced contacts within the mercury switch. The other end of the body on the side of the partition remote from the buoyant mercury switch supports a battery, a momentarily actuatable test switch and an electrically actuated signal generating device, the mercury switch, signal generating device and battery being electrically connected in a loop-type circuit. A bypass circuit is provided for bypassing the mercury switch and the test switch is serially connected in the bypass circuit.

Abstract: A stability meter comprises a translational accelerometer (1) which has a working axis along which it is sensitive to gravity. The meter is mounted on a vessel with the working axis horizontal when the vessel is in the upright position such that it transmits signals proportional to the sine of the angle of roll of the vessel to a microprocessor based apparatus (2). A microprocessor (12) conducts a Fast Fourier Transform on a plurality of samples from the accelerometer (1) in order to determine the dominant rolling frequency. The apparatus (2) comprises a display (8), a printer (9), a keyboard (10), a clock (14) and memory unit (16). The dominant rolling frequency is used to calculate the transverse metacentric height of the vessel. The value of the transverse metacentric height is transmitted to the display (8) as a measure of the stability of the vessel.

Abstract: A signaling device is actuated for a limited period of time if a toilet seat cover is not promptly lowered following flushing of the toilet. In the preferred form, an electrically operated signaling device is coupled to an electrical power source through a magnetically actuated switch at the front of the toilet tank and also through a second switch. A magnet fastened to the seat cover closes the magnetically actuated switch when the cover is in the raised position and movement of a float in the toilet tank in response to flushing closes the second switch for a limited period following initiation of flushing. The device reminds users of the toilet to close the cover. This avoids discomfort to a subsequent user of the toilet and assures that small children and pets are blocked from the toilet bowl.

Abstract: An automatic reorder and alarm system for use with residential fuel-oil tanks which sends reorder and alarm data to a central station over the direct-dial telephone network when the fuel-oil level in the tank falls below a predetermined value or when an alarm situation, such as low temperature, occurs at the tank location. An inexpensive sensor/sending unit located at each customer tank includes a simple sensor which mounts on either the tank or an existing fuel-oil level gauge, a microcontroller circuit and a modem circuit. The microcontroller circuit uses a simple low-stability oscillator as a reference for internal operations and for modem transmission frequencies. Because the oscillator frequency cannot be precisely determined due to component tolerances and has a substantial amount of drift, a special data transmission format is used for data transmission over the telephone lines between the microcontroller and the central station.

Abstract: A switching device comprising a reed switch of a normal open type turned on and off by a magnetic field, a fixed bias magnet located in an area where the switch operates stably, and a starting magnet located opposite to the fixed bias magnet with the switch interposed between them and capable of applying a magnetic field, reverse to that of the fixed bias magnet, to the switch. When the starting magnet is carried close to the switch, its a magnetic field overcomes that of the fixed bias magnet to control the switching-on and -off of the switch, and when it is carried remote from the swtich, the fixed bias magnet controls the switching-on and -off of the switch.

Abstract: An apparatus for checking the workability of a float assembly used to determine the level of liquid in a vessel is disclosed and comprises: a float extension associated with the float of the float assembly and movable when the float assembly is in working order in response to the movement of the float caused by changing the level of liquid in the vessel; a sensor located in spaced relation to the float extension and acting to provide a signal when the float extension is in a predetermined position; and a checking system capable of being activated to move the foat extension into the predetermined position without regard to the level of liquid in the vessel when the float assembly is workable.

Abstract: A washer-type machine containment pedestal tray having sensor-shutoff device for removing power from the washing machine. The invention provides a pedestal for mounting a washing machine thereon and further, that is capable of containing overflow water should the machine malfunction. The collection of water in the containment pedestal tray actuates a float which in turn trips an electrical switch to remove operative power from the washing machine motor, thus stopping the overflow. Adjunct means are also used on the switch for sounding an audible alarm to operating personnel.

Abstract: A monitor and filler assembly providing an easily observable reading as to the fluid level in a reservoir such as an automatic transmission or crankcase of an automobile. The filler may be integrally formed with the monitor to allow for easy replenishing of the reservoir fluid to ensure proper operation of the automobile.

Abstract: A method and apparatus are disclosed for measuring changes in relative distance between a float and both a signal source and a detector. Also disclosed is the advantageous use of such an apparatus for detecting losses as little as 0.02 gallons of liquid per hour from a tank otherwise capable of storing 1,000 gallons or more of such a liquid.

Abstract: An oil gauge accessory for automotive vehicles and the like having a float switch disposed in a casing adapted to be mounted for vertical adjustment alongside the crankcase oil pan and to be connected by suitable tubing at the bottom thereof to the drain opening of the oil pan so that crankcase oil and the float switch rises in the casing to the same level as in the oil pan. Signal means such as different colored lights and a normally open manually operable switch in-circuit with the float switch and a suitable power source, are mounted so as to be visible to and operable by the driver of the vehicle. The casing is adjustable so that when the manual switch is closed, the float switch energizes either one of the signal means which indicates a proper level of oil in the crankcase or the other signal means which indicates that the oil level in the crankcase is low and needs to be replenished.

Abstract: An improved buoyant alarm device which provides an indication of a disturbance to a quiescent level of a body of water. The device includes a cover assembly and a buoyant body. The cover assembly includes a cover member and a support member. The support member provides a subassembly support for electrical components which are mounted thereto and for forming, with the cover member, an enclosed water-tight chamber for housing the electrical components.

Abstract: The oil detecting switch includes a light oil float switch, a water float switch and a heavy oil float switch. When the light oil float switch is closed, a relay is activated energizing a light oil indicator light and its associated coil. The coil is part of a relay which inhibits pumping action. When the water float switch is activated, the inhibiting relay is bypassed so that pumping action can continue. When the heavy oil float switch is activated and closed, a relay is activated which energizes a heavy oil indicator light and its associated coil. The coil is part of a relay which inhibits pumping action. The light oil indicator light, its associated coil and the water indicator light are bypassed when the heavy oil float switch is activated. The status of the float switches is monitored by an analog-to-digital converter associated with a Remote Monitoring System Transmitter.

Abstract: A fluid measurement gauge is principally used to measure the fluid level in large underground storage tanks, such as for storing gasoline at service stations. A housing is positioned vertically in the fluid and includes a leadscrew which is driven by a stepper motor. A nut is mounted for longitudinal movement along the leadscrew. A float encircles the housing and includes a magnet at the surface of the fluid level. A magnetic sensor, such as a Hall-effect switch, is mounted on the nut and driven in selected steps downward to encounter the magnet mounted in the float. A reference position is marked at the top of the housing and the fluid level is measured downward from the reference position by detecting the magnet by operation of the magnetic sensor. An additional float can be provided to detect the interface between two fluids such as gasoline and water. The second float is further provided with a magnet to be detected by the magnetic sensor.

Abstract: A gas flowmeter includes an oil-filled tube coupled to the gas flow line and a float lifted by gas flow. An LED lamp transmitter and a photoresistor receiver are coupled to a guard telescoped over the tube. The LED lamp has an integrated concentrating lens to define a concentrated sharp beam passing through a small barrel located in a guard slot for close coupling the light beam to the tube. The photoresistor receiver includes a similar barrel in an opposite slot in accurate alignment with the transmitter barrel. The receiver includes a photoresistor connected in a dividing network to define an input node to a regenerative "Schmitt" switch which actuates a solid state control relay to indicate a limit position of the float. A mounting plate has a correspondingly mounted light transmitter housing and photoresistor housing. The housings are formed from the same casting. The housings include similar integral clamping tongues located in slots on the opposite sides of the guard.

Abstract: An improved circuit arrangement is described which is used with a buoyant device for indicating a disturbance to the quiescent level of a body of water. The circuit arrangement includes an encoder and transmitter which are supported by the device and which are adapted for transmitting encoded information in accordance with a predetermined pulse code to a remote receiver and alarm. Transmission of the encoded signal is terminated after a predetermined interval of time. The encoder and transmitter are coupled in the circuit for enhancing the turn off of a bi-stable switching circuit.

Abstract: A circuit for sampling the conditions of a liquid level sensor for a short period of time after the circuit is turned on and energizing a warning indicator for an initial check-out period that is followed by continuous energization in the event the sensor indicates a low liquid level condition during the sampling period.

Abstract: A fluid reservoir with a fluid-level sensor includes a manual testing device consisting of two separate but cooperative rods. The fluid-level sensor consists of a float within the reservoir and a reed switch which is closed to cause a low fluid-level alarm when the float is lower than a predetermined level. The testing device serves to depress the float to below that level to ensure that the switch and the alarm are working. A first rod is supported by a filter mounted at the top of the reservoir. A second rod is supported by a flexible cover which fits over the top of the reservoir. The rods are coaxial and free to move downward far enough to push the float to below the above level. Having the two rods separable allows the cover to be removed easily without damaging the manual testing device.

Abstract: A fluid-quantity alarming system for a brake cylinder comprises a brake master cylinder body, a reservoir disposed on and connected to the cylinder body to be biased relative to the central axis of the master cylinder, the reservoir including an opening in a plane passing through the central axis of the master cylinder for fluid communication between the master cylinder body and the reservoir, an attachment hole located adjacent to the corner thereof away from the central axis of the master cylinder, and at least one blind female screw adjacent to the attachment hole, a switch case including a switch therein with a lead extending from the switch, a flange attached to the lower part of the switch case with a hole therein and a screw, and a float disposed around the switch case to be vertically moved in accordance with liquid level in the reservoir. The float includes means to actuate the switch when the float is located beside the switch.

Abstract: In case where a cylindrical gasoline tank embedded in the underground of a gasoline station is of the horizontal type, a liquid level sensor for sensing the liquid level of the gasoline is disposed in the tank, the liquid level in the tank as sensed by the sensor is converted into an electric signal, the electric signal is converted into a signal expressive of the quantity of the gasoline received in the tank by utilizing a segmental function, and this signal is used to indicate the received quantity of the gasoline with electric-light numerals.

Abstract: A liquid level system employs a bellows which is in flow communication with a differential pressure unit by a column of reference liquid. A float in the bellows carries a switch which energizes an alarm when liquid in the column is lost.

Abstract: Fluid level indicator comprises a float suspended at the apex by wires from the cover of a fluid reservoir. The float has an upper chamber and a lower chamber separated by an intermediate piece having a concave surface facing the apex. A metal ball in the upper chamber rolls into a depression at the center of the surface to bridge two switch contacts when the fluid level is low and the float is suspended by the wires, which are connected to the contacts. The float is top-heavy and rolls over to open the switch when the fluid level is high enough to permit the suspending portion of the wires to slacken.

Abstract: A sump pump detection and alarm system, comprising electrical circuits and components to detect the existence of three different conditions, namely (1) a high water condition with electric power still available, (2) a high water condition when electrical power has failed, and (3) a failure of electrical power to the sump pump even though there is no high water level at the time, and to energize an alarm when detected to indicate which of the three conditions exists. The invention includes remote alarm stations, and in addition connections to the on-premises telephone line to produce a busy signal or other signal when such number is dialed in the event one of the three sump pump conditions exists, plus connections to a radio transmitter to transmit a radio signal when one of the said conditions exist.

Abstract: A device for detecting the quantity of a refrigerant circulating in an air conditioner for vehicles, provided with a sensing means which comprises a body having a hollow portion of a construction open to the outside thereof, projecting into the interior of the refrigerant receiver of the air conditioner. The sensing means also includes a floating element disposed within the hollow portion so as to float on the surface of the refrigerant therein. Thus, the sensing means has excellent resistance to shocks and vibrations, and can also be mounted in the refrigerant receiver even after the latter has been assembled. Also provided is an alarm means electrically connected with the sensing means to be actuated in response to the motions of the floating element, which may comprise a comparator means coupled to a time constant circuit, thus providing a stable alarm operation.

Abstract: A liquid level detecting and warning device of the kind including a tubular member having a mounting portion fitted on an opening of a reservoir and a float guiding portion downwardly extending from the mounting portion, a float having a magnet and slidably fitted around the float guiding portion, a reed switch disposed within the float guiding portion, terminals connected to the reed switch through lead wires, and a cover member covering the opening of the reservoir and the mounting portion of the tubular member. The tubular member is formed to have at least two projection radially outwardly projecting from the upper end portion thereof.

Abstract: A magnetic sensing device for sensing the proximity of a gas lift plunger up from the bottom of an oil or gas producing well is used to initiate the off cycle of the well and which comprises only one moving component, a magnet which is attracted to the plunger, completing an electrical circuit to a unit for controlling the operation of the well. The magnet is returned to its resting position by a ferrous set screw adjacent the magnet which attracts the magnet once the gas lift plunger has passed the field of the magnet sensor. The magnet and electrical contacts for the sensing device are enclosed in a molded plastic housing which can be easily opened to repair or replace any worn components.

Abstract: Control apparatus for an electrical load device, comprising a relay having a winding and a set of normally open contacts which are closed and opened, after short delays, upon energization and deenergization respectively of the winding, first and second switches arranged to be closed and opened in predetermined sequences, a first circuit for supplying electrical energy from a source to the winding through both the switches series, and a second circuit for supplying electrical energy to the winding and the load device from the source through one of the switches and the contacts of the relay, the second circuit connecting the contacts in parallel with the other of the switches.

Abstract: A fluid-level detector comprises a container, here a brake-fluid reservoir for an automotive vehicle, adapted to hold a supply of a fluid and containing a float connected via a link arm to a permanent magnet for displacement of the magnet vertically through a predetermined magnet position on vertical displacement of the float through a predetermined float position corresponding to a fluid level at which a signal is to be given. A pair of contacts outside the container can be engaged by a switch element which is displaceable toggle-fashion by the magnet between a closed position engaging and forming a closed circuit with the contacts and an open position out of engagement with at least one of the contacts.

Abstract: This invention relates to an improved method and apparatus for detecting the level of a first fluid. It includes a reservoir within the first fluid, the reservoir being bounded by a flexible membrane at its lower portion for containing a second fluid. The reservoir contains at least one switching means biased to assume a first position when the second fluid is below a predetermined level and adapted to assume a second position upon the rising of the first fluid into pressure exerting contact with the flexible membrane. The rising first fluid compresses the lower flexible membrane portion of the reservoir and causes the second fluid within the reservoir to also rise thereby causing the switching means to assume the second position.

Abstract: An inspection system for a group of tanks, comprises a generator at each tank in which the temperature and the level of the liquid contained in each tank are converted into series data digital signals and start mark signals; and the series data signals are synchronized with clock signals and are transmitted to a receiver. The receiver includes a selector and pulse discriminator for selecting and detecting the start mark signals from a selected generator out of the received series data signals in the receiver. Clock signals are synchronized with the clock signals of the generator side by using the start mark signals; the received and selected series data signals are converted into parallel data signals and the content of the converted parallel data signals is displayed by an indicator to indicate the temperature and level of the liquid in the selected tank.

Abstract: Audible or visual warning signals are employed in a pump system having a primary and an auxiliary pump to indicate loss of power or a malfunctioning pump. Float switches react to a rising liquid level, thereby opening fail-safe circuits, and closing warning circuits which give sensory perceptible signals.