Liquid level gauge with removable hall device

• US 20030084720A1
• Filed: 01/07/2003
• Published: 05/08/2003
• Est. Priority Date: 01/11/2001
• Status: Active Grant

• Current Assignee: Rochester Sensors LLC
• Original Assignee: Rochester Gauges Incorporated
• Inventors: Ross, Herbert G. Jr.
• Granted Patent: US 6,679,116 B2
• Time in Patent Office: Days
• US Class Current: 73/317
• CPC Class Codes: G01F 23/34 using mechanically actuated indicating means G01F23/38 takes precedence
• CPC Class Codes: G01F 23/38 using magnetically actuated indicating means

Abstract

A liquid level gauge assembly including a dial assembly having a shaped magnet and a removable magnetic detector with a magnetic sensor, preferably a Hall sensor. The dial assembly can provide both visual and electrical signal outputs of the liquid level measured by the gauge assembly. The shaped magnet has a variable thickness which, in cooperation with the Hall sensor, provides a linear output signal from the detector over more than 270 degrees.

Claims

1. A gauge dial assembly comprising:

a. a base having a pivot axis;

b. a generally circular shaped magnet having a variable thickness and having a magnetic axis having magnetic poles at the three o'"'"'clock and nine o'"'"'clock positions, said shaped magnet being pivotable about a pin and said pivot axis;

c. a cover attached to said base, wherein said cover defines a channel for receiving a magnetic detector; and

d. said pin extending from either said base or said cover along said pivot axis.

2. A gauge dial assembly of claim 1 further comprising:

a magnetic detector releasably attached to said cover such that said magnetic detector is operatively adjacent to said magnet.

3. A gauge dial assembly of claim 1 further comprising:

a pointer extending from said shaped magnet to provide a visual indication of rotation of said magnet.

4. A gauge dial assembly of claim 3 further comprising:

indicia located on said base for indicating, visually, liquid level.

5. A gauge dial assembly of claim 1 wherein said shaped magnet has a magnetic null at the twelve and six o'"'"'clock positions.

6. A gauge dial assembly of claim 5 wherein said shaped magnet has a north pole at said nine o'"'"'clock position and a south pole at said three o'"'"'clock position.

7. A gauge dial assembly of claim 1 wherein said shaped magnet has a thickness at approximately the eleven o'"'"'clock position which decreases in a counter clockwise direction to approximately the six o'"'"'clock position and which increases in thickness from the six o'"'"'clock position to the approximately one o'"'"'clock position.

8. A gauge dial assembly of claim 5 wherein said shaped magnet has a thickness at approximately the eleven o'"'"'clock position which decreases in a counter clockwise direction to approximately the six o'"'"'clock position and which increases in thickness from the six o'"'"'clock position to approximately the one o'"'"'clock position.

9. A gauge dial assembly of claim 1 wherein the thickness of said shaped magnet is varied to produce a substantially linear change in magnetic flux around the periphery of the said shaped magnet.

10. A gauge dial assembly comprising:

a. a base having a pivot axis;

b. a shaped magnet having a generally circular shape in a plane perpendicular to said pivot axis, and having magnetic poles at the three o'"'"'clock and nine o'"'"'clock positions and a variable thickness parallel to said axis;

c. a cover attached to said base, wherein said cover defines a channel for receiving a magnetic detector; and

d. a pin extending from either said cover or said base along said pivot axis.

11. A gauge dial assembly of claim 10 further comprising:

a magnetic detector releasably attached to said cover such that said magnetic detector is operatively adjacent to said magnet.

12. A gauge dial assembly of claim 10 further comprising:

a pointer extending from said shaped magnet to provide a visual indication of rotation of said magnet.

13. A gauge dial assembly of claim 12 further comprising:

indicia located on said base for indicating visually liquid level.

14. A gauge dial assembly of claim 10 wherein said shaped magnet has a magnetic null at the twelve o'"'"'clock and six o'"'"'clock positions.

15. A gauge dial assembly of claim 14 wherein said shaped magnet has a north pole at the nine o'"'"'clock position and a south pole at the three o'"'"'clock position.

16. A gauge dial assembly of claim 10 wherein said shaped magnet has a thickness at approximately the eleven o'"'"'clock position which decreases in a counter clockwise direction to approximately the six o'"'"'clock position and which increases in thickness from the six o'"'"'clock position to approximately the one o'"'"'clock position.

17. A gauge dial assembly of claim 14 wherein said shaped magnet has a thickness at approximately the eleven o'"'"'clock position which decreases in a counter clockwise direction to approximately the six o'"'"'clock position and which increases in thickness from the six o'"'"'clock position to approximately the one o'"'"'clock position.

18. A gauge dial assembly of claim 10 wherein the thickness of said shaped magnet is varied to produce a substantially linear change in magnetic flux around the periphery of the said shaped magnet.

19. A gauge for liquid level measurement comprising:

a gauge head defining a passageway;

a support shaft extending from said passageway having and upper and lower end;

a drive shaft rotatably mounted on said support shaft having a first and second end;

a pinion gear attached to said first end of said drive shaft;

a magnet attached to said second end of said drive shaft;

a float arm being pivotally attached to said lower end of said support shaft;

a second gear attached to said float arm which rotates in response to movement of said float arm;

said second gear intermeshing with said pinion gear;

a dial assembly mounted on said gauge head on the side opposite of said passageway comprising;

a base having a pivot axis;

a generally circular shaped magnet having variable thickness and having a magnetic axis, said shaped magnet being pivotal about said pivot axis;

a cover attached to said base, wherein said cover defines a channel for receiving a magnetic detector;

a pin extending from either said base or said cover along said pivot axis; and

said dial assembly being positioned such that said magnet mounted on said drive shaft and said shaped magnet are magnetically coupled such that rotating of said magnet causes said shaped magnet to rotate.

20. A gauge assembly of claim 19 further comprising:

a magnetic detector releasably attached to said cover such that said magnetic detector is operatively adjacent to said magnet.

21. A gauge assembly of claim 19 wherein said shaped magnet has a thickness at approximately the eleven o'"'"'clock position which decreases in a counter clockwise direction to approximately the six o'"'"'clock position and which increases in thickness from the six o'"'"'clock position to approximately the one o'"'"'clock position.

22. A gauge assembly of claim 20 wherein said shaped magnet has a magnetic null at the twelve o'"'"'clock and six o'"'"'clock positions and magnetic poles at the three and nine o'"'"'clock positions.

23. A dial assembly comprising:

a base having a pivot axis;

a generally circular shaped magnet having variable thickness and having a magnetic axis, said shaped magnet being pivotable about said pivot axis;

a cover attached to said base, wherein said cover is dimensioned to receive a magnetic detector;

a pin extending from either said base or said cover along said pivot axis; and

a magnetic detector capable of being releasably attached to said cover.

24. A dial assembly of claim 23 wherein said magnetic detector is releasably attached to said cover such that said magnetic detector is operatively adjacent to said magnet.

25. A dial assembly of claim 23 wherein said shaped magnet has a thickness at approximately the eleven o'"'"'clock position which decreases in a counter clockwise direction to approximately the six o'"'"'clock position and which increases in thickness from the 6 o'"'"'clock position to approximately the one o'"'"'clock position.

26. A dial assembly of claim 25 wherein said shaped magnet has a thickness at approximately the eleven o'"'"'clock position which decreases in a counter clockwise direction to approximately the six o'"'"'clock position and which increases in thickness from the six o'"'"'clock position to approximately the one o'"'"'clock position.

27. A dial assembly of claim 23 wherein said shaped magnet has a magnetic null at the twelve and six o'"'"'clock positions and magnetic poles at the three and nine o'"'"'clock positions.

28. A dial assembly of claim 25 wherein said shaped magnet has a magnetic null at the twelve and six o'"'"'clock positions and magnetic poles at the three and nine o'"'"'clock positions.

29. A removable magnetic detector adapted to be used with a dial assembly equipped with a magnet, comprising:

a housing adapted to be removably attached to a dial assembly; and

a magnetic sensor, wherein said magnetic sensor is located in said housing.

30. A magnetic detector of claim 29 wherein said magnetic sensor is a Hall effect sensor.