Fuel level sensor
First Claim
1. Apparatus for sensing the level of fluid within a container comprising:
- a) a base fixed within the container;
b) a movable member supported by the base for relative positioning with respect to said base;
c) a float member that moves relative to the base as the level of fluid in a container changes;
d) an arm attached to the movable member and float member wherein the position of the float is translated into movement of the moveable member with respect to said base;
e) at least one magnetic flux sensor that is housed within a cavity containing encapsulant within the base located within said container and is coupled to one of the moveable member or base for creating an electrical output signal in response to a change in magnetic flux density; and
f) at least one magnet disposed proximate the magnetic flux sensor coupled to one of the moveable member or base for providing a magnetic field to induce a change in electrical output response from the magnetic flux sensor as the float member moves with changes in fluid level.
2 Assignments
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Accused Products
Abstract
A fuel level sensor for sensing and monitoring the level of remaining fluid in a container such as a fuel tank for a motorized vehicle is disclosed. The fuel level sensor incorporates an improved float and pivot arm member attached to a hub that rotates about a pivot base. The conventional resistor card technology, commonly found in automotive applications for translating the position of the float into an electrical signal, is replaced by a more reliable non-contact magnetic flux sensing circuit. The fuel level sensor incorporates a magnetic sensor and magnetic circuit in a commonly known and practiced rotational position sensor configuration for determining the angular position of a hub relative to its pivot base, where the hub is attached to a conventional float-arm member and the base remains stationary relative to the fuel container. The preferred embodiment includes a magnetic flux sensor positioned between two movable magnets. The magnetic flux sensing element is a Hall effect integrated circuit, magnetoresistor, magnetodiode, magnetotransistor, or similar magnetic flux sensing element with associated electronic circuitry having adjustable or programmable features including ratiometry, gain, offset voltage, temperature coefficient, and output signal range limiting. Critical electronic components are hermetically sealed making the fuel level sensor fully submersible in fuel for long term fuel exposure.
56 Citations
24 Claims
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1. Apparatus for sensing the level of fluid within a container comprising:
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a) a base fixed within the container; b) a movable member supported by the base for relative positioning with respect to said base; c) a float member that moves relative to the base as the level of fluid in a container changes; d) an arm attached to the movable member and float member wherein the position of the float is translated into movement of the moveable member with respect to said base; e) at least one magnetic flux sensor that is housed within a cavity containing encapsulant within the base located within said container and is coupled to one of the moveable member or base for creating an electrical output signal in response to a change in magnetic flux density; and f) at least one magnet disposed proximate the magnetic flux sensor coupled to one of the moveable member or base for providing a magnetic field to induce a change in electrical output response from the magnetic flux sensor as the float member moves with changes in fluid level. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. Apparatus for sensing the level of fluid within a container comprising:
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a) a base fixed relative to the container; b) a movable member supported by the base for relative positioning with respect to said base; c) a float member that moves relative to the base as the level of fluid in a container changes; d) an arm attached to the movable member and float member wherein the position of the float is translated into movement of the moveable member with respect to said base; e) a sensor assembly having at least one magnetic flux sensor coupled to one of the moveable member or base for creating an electrical output signal in response to a change in magnetic flux density and a lead frame that helps to locate the magnetic flux sensor with respect to the moveable member or base; and f) at least one magnet disposed proximate the magnetic flux sensor coupled to one of the moveable member or base for providing a magnetic field to induce a change in electrical output response from the magnetic flux sensor as the float member moves with changes in fluid level. - View Dependent Claims (15, 16, 17)
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18. Apparatus for sensing the level of fluid within a container comprising:
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a) a base fixed within the container; b) a movable member supported by the base for relative positioning with respect to said base; c) a float member that moves relative to the base as the level of fluid in a container changes; d) an arm attached to the movable member and float member wherein the position of the float is translated into movement of the moveable member with respect to said base; e) at least one magnetic flux sensor that is located within said container and is coupled to one of the moveable member or base for creating an electrical output signal in response to a change in magnetic flux density; and f) at least one magnet disposed proximate the magnetic flux sensor coupled to one of the moveable member or base for providing a magnetic field to induce a change in electrical output response from the magnetic flux sensor as the float member moves with changes in fluid level; g) said base comprising an encapsulant for isolating the flux sensor from harsh fluids found in liquid fuels. - View Dependent Claims (19, 20)
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21. A method for fabricating a sensor for sensing the level of fluid within a container comprising:
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a) fixing a base within the container; b) coupling a movable member to the base for relative positioning with respect to said base; c) providing a float member that moves up and down as the level of fluid in a container changes; d) attaching the float member to the moveable member by means of an arm attached to the moveable member and float member wherein the position of the float is translated into movement of the moveable member with respect to said base; e) positioning a magnetic flux sensor within the chamber by coupling said magnetic flux sensor to one of the moveable member or base to create an electrical output signal in response to a change in magnetic flux density;
f) positioning at least one magnet disposed proximate the magnetic flux sensor coupled to one of the moveable member or base for providing a magnetic field to induce a change in electrical output response from the magnetic flux sensor as the float member moves up and down with changes in fluid level; and
g) providing an encapsulant for isolating the magnetic flux sensor from harsh fluids found in liquid fuels. - View Dependent Claims (22)
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23. Apparatus for sensing the level of fluid within a container comprising:
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a) a base fixed within the container; b) a movable member supported by the base for relative positioning with respect to said base; c) a float member that moves relative to the base as the level of fluid in a container changes; d) an arm attached to the movable member and float member wherein the position of the float is translated into movement of the moveable member with respect to said base; e) at least one magnetic flux sensor that is located within said container and is coupled to one of the moveable member or base for creating an electrical output signal in response to a change in magnetic flux density; and f) at least one magnet disposed proximate the magnetic flux sensor coupled to one of the moveable member or base for providing a magnetic field to induce a change in electrical output response from the magnetic flux sensor as the float member moves with changes in fluid level; g) said moveable member comprising a maget hub that has at least one integral axial spring member that positions the magnet toward the magnet hub center axis.
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24. A method for fabricating a sensor for sensing the level of fluid within a container comprising:
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a) fixing a base within the container; b) coupling a movable member to the base for relative positioning with respect to said base; c) providing a float member that moves up and down as the level of fluid in a container changes; d) attaching the float member to the moveable member by means of an arm attached to the moveable member and float member wherein the position of the float is translated into movement of the moveable member with respect to said base; e) positioning a magnetic flux sensor within the chamber by coupling said magnetic flux sensor to one of the moveable member or base to create an electrical output signal in response to a change in magnetic flux density; f) positioning at least one magnet disposed proximate the magnetic flux sensor coupled to one of the moveable member or base for providing a magnetic field to induce a change in electrical output response from the magnetic flux sensor as the float member moves up and down with changes in fluid level; and g) providing an encapsulant that protects the magnetic flux sensor by dampening mechanical vibration and shock.
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Specification