Sensor and system for measuring the level of a liquid in a container

Claim 1

In a system for measuring the level of a liquid in a container (12), a sensor (10) comprising: a vertically extending support structure (14) adapted to be received and retained within the container; a pair of electrically spaced terminals (48); at least one circuit element (46) electrically coupled between the terminals and having an electrical property which varies at different portions of the circuit element between the terminals, the circuit element being supported on the support structure; means for changing the effective electrical property of the circuit element between the terminals, said means for changing being electrically coupled to the different portions of the circuit element and being supported on the support structure to extend vertically therealong, said means for changing including first and second support members (42, 44) having inner and outer surfaces and first and second conductors (50, 52, 56), the first and second support members being juxtaposed so that the inner surfaces face one another in normally spaced apart relationship with the first and second conductors being laterally spaced in actuating proximity between the inner surfaces, the first and second conductors being horizontally movable into electrical conducting relationship at various vertical positions therealong corresponding to different values of the electrical property in response to application of a horizontal force at one of the outer surfaces; and a float mechanism (34) connected to said support structure to reciprocate vertically in response to the level of the liquid in the container, said float mechanism including a buoyant part (36) and actuator means (38) connected to the buoyant part in fixed vertical relationship thereto for exerting the horizontal force, the electrical conducting first and second conductors providing an electrical signal which is a function of the vertical position of said actuator means along the support structure.

Claim 3

A system for measuring the level of a liquid in container, the system comprising: a vertically extending support structure adapted to be received and retained within the container; a pair of electrically spaced terminals; at least one circuit element electrically coupled between the terminals and having an electrical property which varies at different portions of the circuit element between the terminals, the circuit element being supported on the support structure; means for changing the effective electrical property of the circuit element between the terminals, said means for changing being electrically coupled to the different portions of the circuit element and being supported on the support structure to extend vertically therealong, said means for changing including first and second support members having inner and outer surfaces and first and second conductors; the first and second support members being juxtaposed so that the inner surfaces face one another in normally spaced apart relationship with the first and second conductors being laterally spaced in actuating proximity between the inner surfaces, the first and second conductors being horizontally movable into electrical conducting relationship at various vertical positions therealong corresponding to different values of the electrical property in response to application of a horizontal force at one of the outer surfaces; a float mechanism connected to said support structure to reciprocate vertically in response to the level of the liquid in the container, said float mechanism including a buoyant part and actuator means connected to the buoyant part in fixed vertical relationship thereto for exerting the horizontal force; said so conducting conductors providing an electrical signal which is a function of the vertical position of the actuator means along the support structure; and a circuit coupled to said conductors for processing said electrical signal to provide a corresponding liquid fuel signal indicating the level of the liquid in the container.

Claim 4

A system for measuring the level of a liquid in container, the system comprising: a vertically extending support structure adapted to be received and retained within the container; a pair of electrically spaced terminals; at least one circuit element electrically coupled between the terminals and having an electrical property which varies at different portions of the circuit element between the terminals, the circuit element being supported on the support structure; means for changing the effective electrical property of the circuit element between the terminals, said means for changing being electrically coupled to the different portions of the circuit element and being supported on the support structure to extend vertically therealong, said means for changing including first and second support members having inner and outer surfaces and first and second conductors; the first and second support members being juxtaposed so that the inner surfaces face one another in normally spaced apart relationship with the first and second conductors being laterally spaced in actuating proximity between the inner surfaces, the first and second conductors being horizontally movable into electrical conducting relationship at various vertical positions therealong corresponding to different values of the electrical property in response to application of a horizontal force at one of the outer surfaces; a float mechanism connected to said support structure to reciprocate vertically in response to the level of the liquid in the container, said float mechanism including a buoyant part and actuator means connected to the buoyant part in fixed vertical relationship thereto for exerting the horizontal force; said so conducting conductors providing an electrical signal which is a function of the vertical position of the actuator means along the support structure; and a circuit coupled to said conductors for processing said electrical signal to provide a corresponding liquid fuel signal indicating the level of the liquid in the container.