Abstract: The present invention provides an automatic cut off switch which grounds the magneto-spark plug circuit of a small gasoline engine shutting the engine down when the quantity of lubricating oil within the sump falls below a predetermined quantity. The switch is operated by a balance beam float assembly housed within a protective shroud. The protective shroud acts to collect a relatively stable pool of oil, representative of the quantity of oil remaining in the sump, for activation of the balance beam float. Upon refilling of the oil sump the switch automatically resets thereby permitting re-start of the engine.

Abstract: An electric signal in an electrical level measuring transducer shall be generated in an explosion-proof manner, which continuously depends on the level in the interior of a container. The buoyancy of a float 14 is converted into a movement of a permanent magnet 36. The permanent magnet moves in the area of a Hall generator 44. The signal processing elements 48 are disposed in a tightly closed housing in explosion-proof manner. The Hall generator 44 is located in a non-magnetic part of the wall 38 of the housing 20.

Abstract: An automobile hydraulic braking circuit comprises two reservoirs in addition to the main hydraulic fluid reservoir. One additional reservoir can replenish the other which in turn can replenish the main hydraulic reservoir. A peristaltic pump controls fluid flow to the main reservoir from the adjacent additional reservoir. Probes in the additional reservoirs operate in conjunction with control circuitry to inhibit operation of the pump to prevent contaminated fluid from being supplied to the main reservoir.

Abstract: Apparatus for warning of a leak in a hydraulic system. The warning apparatus includes a liquid level sensor, mounted above the hydraulic fluid reservoir, and a signal assembly. The sensor includes an expansion chamber with a float chamber pipe inside. The float chamber pipe opens into the expansion chamber a substantial distance above the expansion chamber bottom. Hydraulic fluid, which expands when the equipment is started, flows through the open pipe end and into the expansion chamber. If the liquid level in the float chamber pipe drops below a set level, a float in the pipe also drops to activate the signal assembly. If the hydraulic system springs a leak, the alarm activates to minimize damage. Before re-starting the equipment the excess fluid held in the expansion chamber is allowed to drain back into the reservoir. Drainback is done either passively, through a constricting passageway at the expansion chamber bottom, or actively, typically by the operator after use.

Abstract: An air humidifier includes a water level detector that detects the water level in the water reservoir, and first and second light-emitting elements. The first and second light-emitting elements are selectively energized to emit light in response to whether the water level detected by the water level detector is at or above or below a predetermined level so as to permit quick visual inspection of the relative water level in the reservoir.

Abstract: A refrigerant monitor and alarm includes a sensor positioned to detect the level of liquid state refrigerant in the system and provide an electrical output signal therefrom, a digital display for displaying the refrigerant level, and a circuit coupling the digital display to the sensor for actuating the digital display. In a preferred embodiment, the level display is a bar-graph LED-type display incorporated on a control panel also including a refrigerant level alarm and other parameter alarms.

Abstract: A bulk material container comprising a shell made from suitable material, such as aluminum or stainless steel. Disposed within the shell is a floatable rigid follower. The vertical position of the floatable rigid follower varies with the level of flowable bulk material stored in the shell. The rigid follower comprises axially aligned, juxtaposed rigid sections with a flexible wiper secured therebetween. A permanent magnet is carried by the rigid follower for movement therewith and means responsive to a magnetic field are attached to the exterior of the shell to detect the height of the permanent magnet. Indicating means are responsive to the operation of the means responsive to a magnetic field for indicating the level of the rigid follower. In a modification of the bulk material container, the wiper is replaced by an inflatable seal and the floatable rigid follower provides a selectively positionable cover for the bulk material container.

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 level detecting device for detecting the level of liquid in a tank includes a displacer or float displaceable in response to the level of the liquid in the tank, an enclosure tube disposed on the tank and sealed thereagainst so that the exterior of the enclosure tube is isolated from the liquid in the tank and a variable transformer for detecting the displacement of the float. The transformer includes at least two windings disposed adjacent the outside of the enclosure tube and an elongate core disposed within the enclosure tube and coupled to the float so as to be movable therewith, the amount of magnetic coupling between the windings being dependent upon the position of the core in the enclosure tube. Means are provided for generating an output signal representing the amount of magnetic coupling between the windings to derive an indication of the level of the liquid in the tank.

Abstract: A bulk material container comprises a shell made from suitable material, such as aluminum or stainless steel. Disposed within the shell is a follower. The vertical position of the follower varies with the level of flowable bulk material stored in the shell. A permanent magnet is carried by the follower for movement therewith and a magnetic switch operatively responsive to the magnetic field created by the permanent magnet is attached to the exterior of the shell to detect the height of the permanent magnet. A level indicator is responsive to the operation of the magnetic switch for indicating the level of the follower.

Abstract: In a liquid-level transmitter having a swingable support lever (3) which bears a float (7) and a variable electrical resistor (9) actuated thereby, the variable resistor (9) is surrounded by a bell-shaped structural part (1) which is open towards the bottom but otherwise closed. In this way, as in the case of a diving bell, no liquid can enter into the bell-shaped structural part (1) when the level of the liquid rises above the height of the liquid-level transmitter, so that parts of the variable resistor are protected in simple fashion from corrosion due to contact with the liquid to be measured.

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 liquid level sensor adapted to be installed inside a reservoir of a liquid to be monitored. The level sensor includes a float made from magnetic material which moves between two opposed end positions along a predetermined up-and-down path following the top surface level of the liquid. An a.c. coil driven by a pulse generator is located at one end of the float path such that the magnetic material of the float is closer to the coil at this one end of the path than at the opposite end, and is thus a variable part of the "core" of the coil which changes in response to the liquid level in the reservoir. The magnetic flux generated by the coil and/or its inductive reactance, also being a function of the variable core and thus a function of the liquid level, can be monitored electrically to provide an indication of the liquid level to an operator. The level sensor can be used to provide a signal at a predetermined level, or to provide an output which is proportional to the level of the liquid in the reservoir.

Abstract: A magnetic control device having a movable, permanent magnet or fixed-polar portion, a movable element of magnetizable material, i.e., material of high permeability and a plurality of fixed members also of magnetizable material.

Abstract: The invention contemplates a float-operated electrical switching system with two fluid-level indications and with provision for mechanical adjustment of the difference in elevation between the two indicating points. The switches are magnetically actuated in accordance with proximity of a permanent magnet carried by the float. The float is guided on an upright magnetically transparent tube which houses the switches, and for at least one of the switches mechanical adjustment of elevation within the tube is available via external access at the upper end of the tube.

Abstract: In a liquid level detector of the type comprising a fixing rod bearing a winding over virtually the whole of its height, an annular float mounted around the rod and bearing at least one conducting blade constantly in contact with the winding, a warning device comprising a conducting rod sliding in a bore made in the float, the bore having its axis substantially parallel to the axis of the fixed rod, the conducting rod comprising a retaining device, and a conducting surface fixed to the lower end of the fixed rod, the arrangement being such that the conducting rod projects downwardly from the float when the level is higher than a determined warning level and comes into contact with the conducting surface when this level is reached, and electrical connections connecting the winding, the conducting surface, the or each conducting blade and the conducting rod to output terminals, the conducting rod extends at its top end in a supple loop made of conducting wire located in a plane substantially perpendicular to th

Abstract: An automatic chemical analyzer suitable for chemically analyzing a number of analysis items is disclosed. Samples in sample containers are sequentially dispensed to an array of reaction vessels using a first pipetting tube. Reagent solutions selected in accordance with the analysis items are fed to the reaction vessels using a second conductive pipetting tube. The reaction solutions in the reaction vessels are measured by a photometer. When the reagent solutions are sucked into the second pipetting tube, the liquid levels of the reagent solutions in the reagent containers are detected by a liquid level sensor formed by the second pipetting tube and a conductive electrode. The amounts of the reagent solutions remaining in the reagent containers are determined based on the position of the liquid level sensor and the numbers of times of dispense allowed to the reagent solutions with respect to the analysis items are displayed on a cathode ray tube.

Abstract: Swimming pool water level control apparatus includes a remote indicator for sensing the water level in a swimming pool and for turning on and off a water flow control valve to provide water for the swimming pool.

Abstract: Compensating brake fluid reservoirs with a brake fluid alarm device are required for master cylinders of hydraulic brake systems in automotive vehicles. A float chamber, which is disposed in a compensating reservoir and surrounds a float, is defined by a tubular body suspended from an upper end of the reservoir and a bottom element. After insertion of both parts into the reservoir the bottom element cooperates with the lower end of the tubular body such that the float chamber is closed at least to such an extent that the inflow and outflow of the fluid therefrom is inhibited in order to achieve a damping effect. This enables a quick immersion of both parts into the filled reservoir without brake fluid leaking from the reservoir.

Abstract: A float assembly for a sensor provides a float member having a channel passing therethrough, a mounting for the sensor on the float, a guide passing through the channel for guiding the movement of the float member, a stop including a magnet located on the guide for limiting the movement of the float, and a magnetically activated switch included in the float member for activating when in proximity to the stop magnet for indicating that the float member is in proximity to the stop.

Abstract: An overflow control system for use with home appliances such as washing machines, incorporating conventional stand pipe which receives the outlet conduit from the appliance, the stand pipe being provided with an attachment having a displacement, conductivity or a pressure sensor installed for sensing the height of liquids in the stand pipe. This stand pipe may be vertically connected to the sewage line outlet found in a home and the signals from the sensors may be used to shut off the power to the appliance and to excite an alarm. Connected in parallel with the sensors may be a moisture sensor deployed under the appliance which again shuts the power off whenever the machine is inadvertently filled beyond its limits or when leakage occurs.

Abstract: A sewer back up warning system includes a pair of electrically-conductive probe rods fixedly securable within a sewer clean out pipe and being in electrical communication with a sewer back up alarm. An electrically-conductive float is hingedly attached to a free end of one of the rods, such float serving to rise in the clean out pipe as a sewer backs up so as to eventually come into contact with the second rod to thus complete the electrical circuit containing the back up alarm. A corrosion check device is also provided which essentially consists of a manually-operable chain pull for effectively bringing the metallic float into electrical communication with the second rod so as to determine the presence of corrosion build up which would prevent the operation of the alarm.

Abstract: A sensor for detection of the presence of a predetermined level of fluid in an enclosed reservoir, e.g., oil in an engine crankcase or transmission fluid reservoir, and a system for providing a remote indication of the detection of the existence of the predetermined level. The apparatus includes an electrically conductive float disposed within an encapsulator and movable responsive to the liquid level to provide an indication thereof.

Abstract: An overflow control system for use with home appliances such as washing machines, incorporating conventional stand pipe which receives the outlet conduit from the appliance, the stand pipe being provided with an attachment having a displacement, conductivity or a pressure sensor installed for sensing the height of liquids in the stand pipe. This stand pipe may be vertically connected to the sewage line outlet found in a home and the signals from the sensors may be used to shut off the power to the appliance and to excite an alarm. Connected in parallel with the sensors may be a moisture sensor deployed under the appliance which again shuts the power off whenever the machine is inadvertently filled beyond its limits or when leakage occurs.

Abstract: A float is moved upwardly or downwardly by liquid being added to a liquid holding tank. The float carries a first permanent magnet which is moved by the float towards a second magnet which is separated therefrom by a liquid tight partition. The permanent magnets are arranged with like poles directed towards each other so that the permanent magnets will repel each other and movement of the first permanent magnet in response to a liquid level change will cause the second permanent magnet to be moved in response to the repelling force. The second permanent magnet is positioned in line with a depressable control member of a normally closed valve in a gas line. Movement of the second permanent magnet against such control member depresses the control member to open the valve, allowing gas to flow from a storage tank to a piston in a normally closed valve that is located in a second line leading from the gas supply to a horn.

Abstract: A fluid level detector comprising a cylindrical member which includes a mounting portion fitting in the opening of a fluid reservoir and a float guide portion extending downwardly from the mounting portion. A float, provided with a magnet, is slidably fitted over the float guide portion. A lead switch is disposed in the float guide portion. A terminal is connected to the lead switch via a lead 18. A lid member is mounted to close the opening of the reservoir. A terminal holder is integrally formed on the cylindrical member. The lid member includes an upper cover covering the upper portions of the mounting portion and the cylindrical member, and a lower cover. In assembly, after interposing the terminal holder between the upper and lower covers, the cylindrical member and the lid member are mounted to the reservoir as a unit.

Abstract: An oil level indicator for use on a motor vehicle having a tube open at the vehicle oil pan. An elongated stiff oil gauging wire is slidably mounted in the tube. The wire carries a float at its lower end and extends at its upper end into a stationary housing mounted on the vehicle. The housing pivotally mounts a lever connected to a stiff wire and to the slidable contactor of a variable resistance member in the housing. The variable resistance member is connected to a battery and to a guage mounted at the dashboard of the motor vehicle to indicate the oil level in the oil pan.

Abstract: A device is described for detecting the level of the material within a container such as a hopper comprising a cord (18) for suspending a thimble (38) from a balance arm (22) which in turn is suspended through the intermediary of an inclination sensitive switch (26).Modifications are illustrated in which the cord is suspended through a sealed aperture in a lid (40).Another embodiment of the invention comprises a cord (66) for suspending a thimble (38) from a balance arm (62) which is balanced by means of an adjustable tension spring (68) and when pivoted so as to actuate a switch (76).

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: The present invention provides an improvement by adaptation of a rising stem fuel oil gauge for indicating, at a remote location, the quantity of fuel in oil storage tanks commonly used in homes and businesses. The improvement includes a magnet carried on a horizontally positioned level indicating disc, which is attached to the upper end of a vertically rising stem and enclosed within a transparent tube. Markings on the tube correspond to the quantity of fuel oil within the storage tank and the alignment of the indicating disc with a specific marking indicates the fuel oil quantity at any given time. A magnetically actuated reed switch is mounted to the exterior of the tube at a predetermined position, and a power supply and remote alarm are coupled to the switch. When the level of the indicating disc is near the position at which the switch is mounted, the magnet carried on the disc actuates the switch which in turn actuates the remote alarm.

Abstract: The invention is an improved liquid level indicator for the liquid in a reservoir. The invention consists of float mechanism in a framework which permits the float mechanism to be immersed in the liquid in the reservoir and float thereon. The float mechanism magnetically controls a companion device in a hollow enclosure, protected from contact with the liquid in the reservoir. As the level of the liquid in the reservoir changes and the float mechanism follows the changing level of the liquid, it likewise changes the position of the companion device through its magnetic control. The companion device is wired to signal the liquid level at an appropriate read-out site.

Abstract: A method and apparatus for accurately measuring the level of liquid in a storage tank and graphically displaying that measurement. The system is particularly useful in vehicular fuel level measuring applications, since the system provides for sampling the level of the liquid over designated time periods and comparing each sample reading with a previous sampling that is stored and presently controls the display. The graphical display is a unique bar graph comprised of groups of bar-like elements driven to provide a relative indication of the sensed and measured liquid level in contrast with the maximum level that may be sensed.

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.

Abstract: A lubricating oil detector for an internal combustion engine, the detector including a lubricating oil reservoir adapted to be disposed in a chamber of the engine wherein pressure pulsations are produced by reciprocating movement of a piston. An oil level detecting pipe extends to the exterior of a crank case of the engine, the pipe having an end opening at a lowest allowable oil level in the reservoir. A pressure detecting actuator is provided and is adapted to be mounted on the case and connected through a connecting tube to the detecting pipe. When the oil level is below the lowest allowable level, the pressure pulsations in the case are directed to the pressure detecting actuator, which is then actuated to stop the operation of the engine, or to operate an alarm.

Abstract: In an apparatus for detecting the level of fuel oil in a tank of a vessel to control the quantity of fuel oil in the tank, a sensing pipe having a sensing hole in its lower portion is inserted into the tank and gas is continuously supplied into the sensing pipe. Hence, the pressure in the sensing pipe is continuously increased as the level of fuel oil is raised above the level of the sensing hole. When this pressure reaches a desired value, a fluid pressure response device connected to the sensing pipe is operated by the pressure to operate an alarm device, thereby to detect the level of fuel oil above the sensing hole. The pressure in the sensing pipe required to operate the alarm device can be set to a desired value.

Abstract: A housing, a first elongated generally cylindrical member fixed to the housing and having an open end which is adapted to be in open communication with the interior of the sealed transformer casing; this first member also has at least a portion of its length composed of transparent material for viewing the interior. Means, such as a float, are contained in the first cylindrical member for providing a visual indication of the gas emission levels. Additional means are coupled to and communicate with the first cylindrical member for measuring gas emission levels in the transformer and for measuring variations in the internal pressure of the transformer casing. A second generally cylindrical member is fixed to the housing and has one end adapted to extend into the sealed transformer casing. This second member includes means, such as temperature sensors, for detecting changes in the temperature of the dielectric in the transformer casing.

Abstract: The device comprises a float which is guided by a retaining device and cooperates with a switch located adjacent the bottom of a fuel tank and carried by the retaining device. An elastically yieldable device interposed between a support secured to the top wall of the tank and the retaining device biases the latter against the bottom wall of the tank.

Abstract: A radiator cap composed of a cap body, a compression gasket assembly connected to the cap body and adapted to open and close in accordance with the pressure of the coolant in the radiator, a float engaged with the cap body so as to move up and down in accordance with the level of the coolant. The upper edge of the float is formed so that upon contact with a gasket assembly, a valve is formed with said gasket assembly. A reed switch secured to the cap body is opened or closed in response to movement of the float so that the reed switch actuates suitable warning means when the level of coolant falls over a predetermined line.

Abstract: A digital readout fuel gauge for monitoring the liquid level in a fuel storage tank. The device utilizes a pre-amplifier circuit which comprises a voltage divider network utilizing the fuel gauge tank variable resistor on one side of the divider and a variable resistance on the other side which is connected to a signal processor. The output voltage of the signal processor is connected to the analog input of an analog to digital converter. The analog to digital converter changes the DC voltage levels to a four bit BCD code. The output carrying the code is connected to a decimal digit to a seven segment LED decoder. The digits are generated and displayed on LED indicator units. In addition, a voltage comparator circuit compares the output of the signal processor with a reference voltage and when said output is below a predetermined level, the comparator circuit initiates a warning signal.

Abstract: An electro mechanical liquid level sensor is disclosed. The sensor comprises a magnetically operable switch which responds to liquid level in a container to complete a circuit for actuating a warning light or the like. The switch comprises an electrical contact operative in response to a magnetic force which is movable in accordance with liquid level whereby the circuit is completed upon a predetermined change in liquid level. The movable parts of the sensor are self-aligning. The movable contact may be maintained in the circuit closed position independent of liquid level until reset.

Abstract: An electro-mechanical liquid level sensor is disclosed. The sensor comprises a magnetically operable switch in response to liquid level to complete a circuit for actuating a warning light or the like. The switch comprises a movable electrical contact operative to be moved by magnetic force which is variable in accordance with liquid level whereby the circuit is completed upon a predetermined change in liquid level. The movable parts of the sensor and the structure associated therewith are self-aligning.

Abstract: A display device for indicating the value of a measured quantity includes a plurality of display elements, each representative of a primary value range. A driving circuit is responsive to a sensor output signal and activates individual ones of the display elements when the sensor output has a value representative of one of the primary value ranges of the measured quantity, and activates adjacent display elements simultaneously when the sensor output signal represents intermediate value ranges of the quantity.

Abstract: In a liquid level contents indicator for a vehicle hydraulic system of the float-operated electric switch type manually operable mechanism for testing the circuit comprises a push-button located in an end closure cap for a reservoir and the push-button acts on contacts of the electric circuit through a resilient diaphragm which also acts as a return spring for the push-button and provides a seal between the push button and the cap.

Abstract: A float unit having two float portions operates a switching unit to stop the supply of liquid at a selected high level and to reestablish the supply at a selected low level. The switching unit may be a precision snap-acting switch, and the float unit may be integrally formed from glass. In the preferred embodiment, the switch and an upper switch-engaging portion of the float are mounted in a housing which serves as a closure for a container.

Abstract: The invention contemplates an improved electric switch which changes its state via float response to achievement of a particular liquid level. The construction features mechanical seal and shield structure whereby liquid is kept out of the region of float guidance, with the result that float response is substantially isolated from sloshing action and from liquid contamination.

Abstract: The oscillation frequency of the output signal of a ring oscillator is changed in response to a change in the relative position between the coil in the ring oscillator and a float including a conductive member and vertically movable in accordance with changes in the level of a liquid to be measured. The amount of electric power consumed by the ring oscillator itself is changed in accordance with changes in the oscillation frequency of the oscillator output signal. The power consumption of the ring oscillator is detected in accordance with the voltage across a resistor inserted in the power line from the electric power source to the ring oscillator, so that when this voltage attains a predetermined value, an indicator designed to indicate that the liquid level has attained a predetermined level is brought into operation.

Abstract: A dual fluid reservoir for a tandem master cylinder includes front and rear fluid chambers communicated to each other and comprises a lateral partition provided within the casing of the reservoir to block free fluid communication between the two chambers after the fluid level within the chambers drops below a lowest level defined by the lateral partition, and an annular partition provided on the lateral partition to form a float chamber therein, the annular partition being higher than the lateral partition in a predetermined length and including a pair of recessed portions corresponding to the lateral partition to permit fluid flow from the two fluid chambers into the float chamber. Thus, a magnetically operable switch device is mounted on the casing between the two chambers to actuate a warning device and a float is disposed within the float chamber for vertical movement and operatively connected to the switch.

Abstract: A device for detecting the overdischarge of the accumulator as well as the surface level of electrolyte contained in the accumulator comprising a floating member, a case housing the floating member and having a hole through which the electrolyte in the accumulator passes, a means for sucking the electrolyte through the hole into the case, and a magnetically sensing switch arranged to be operated responding to movement of the floating member. At least one chamber communicated with the outside of the case is provided in the case outside the hole through which the electrolyte passes.

Abstract: A measuring device to determine the depth of sediment in the floor of a buried pipe and the rate of flow of water through the pipe.

Abstract: The control for electric sump pumps is operated by a pair of weights operatively attached to the control which has a sealed non-magnetic material housing having a downwardly open recess extending thereinto from its lower surface. A normally open microswitch having a spring control arm extending therefrom and movable downwardly to close the switch, while a permanent magnet is positioned on the arm directly above the recess, and a magnetic metal means is slidably positioned in the recess and operatively connects to the weights. The magnetic metal means attracts the permanent magnet when the metal means is at the upper portion of the recess and this closes the switch arm with the position of the metal means in the housing in relation to the magnet being controlled dependent upon the water level in the sump.