Monte L Herford

US Patent:

6571626, Jun 3, 2003

Filed:

Oct 11, 2001

Appl. No.:

09/975727

Inventors:

Monte L. Herford - Grand Rapids MI

Assignee:

Walbro Corporation - Cass City MI

International Classification:

G01F 2330

US Classification:

73314, 73290 R, 73304 R, 73305, 73308

Abstract:

A fuel level sensor for use with a vehicle fuel tank includes a magnet carrying float assembly that rises and falls with the fuel level to open and close various magnetically activated reed-switches located at different axial positions along a vertically extending electrical circuit. Activating a reed-switch located at a particular vertical position along the electrical circuit causes the overall resistance of the circuit to depend upon the position of the float assembly. The float assembly is capable of freely rotating about the vertical axis of the electrical circuit and carries magnets producing a horizontal magnetic field that can activate a reed-switch from any angular orientation of the float assembly. Thus, assuming the fuel level sensor is provided with a constant voltage source, the sensor is able to determine the fuel level by the amount of electrical current flowing through the circuit. The electrical current outputted from the sensor is sent to a fuel level gauge which translates the electrical signal into a visual reading, thereby informing an operator of the current fuel level.