Magnetically driven gauge with voltage divider

• US 5,357,815 A
• Filed: 12/29/1993
• Issued: 10/25/1994
• Est. Priority Date: 02/10/1993
• Status: Expired due to Term

• Current Assignee: Rochester Gauges Incorporated
• Original Assignee: Rochester Gauges Incorporated
• Inventors: Williamson, Cecil M.
• Primary Examiner(s): Williams, Hezron E.
• Assistant Examiner(s): LARKIN, DANIEL SEAN
• Application Number:
  US08/174,718
• Time in Patent Office: 300 Days
• Field of Search: 73/305, 73/308, 73/313, 73/314, 73/317, 73/866.3, 73/DIG. 5, 338/12, 338/33
• US Class Current: 73/866.3
• CPC Class Codes: F17C 2250/0413 with floats
• CPC Class Codes: G01F 23/36 using electrically actuated indicating means G01F23/38 takes precedence
• CPC Class Codes: Y10S 73/05 Liquid levels with magnetic transmission

Abstract

A gauge assembly (10) utilizing a voltage divider circuit to provide reliable and accurate measurement of a fluid level within a tank (16) or other environment. A pointer assembly (52) pivots about an axis (42) in response to a moving float to indicate the fluid level. A plurality of contact arms (114, 116, 118) extending from a contact plate (58) on the pointer assembly (52) resiliently engage a point (120) along a resistive element (88). The first end of the resistive element is connected to a voltage regulator (100) which is connected to a first contact (94). The second end of the resistive element forms a second contact (96). The point (120) of contact between the contact arms and resistive element is connected to an amplifier (102) which is connected to a third contact (95) forming a low impedance voltage divider circuit.

Claims

1. A gauge for measuring a fluid level, comprising:

(a) a base having a recess and a pivot pin extending therefrom;

(b) a pointer assembly mounted on the pivot pin for rotation about an axis, the pointer assembly including a contact plate thereon, said contact plate including at least one resilient conductive arm and at least one conductive element

(c) a nonconductive board positioned proximate the pointer assembly, said nonconductive board including;

(i) a voltage regulator electrically connected to a first contact and to a resistive element;

(ii) a resistive element formed in a semi-circular arc at a predetermined radius about said axis having first and second ends and contacted by said conductive arm at a point along said resistive element determined by the angular position of the pointer assembly relative to said first axis, said first end connected to said voltage regulator, and said second end connected to a second contact;

(iii) a conductive surface being formed on the board at said axis and contacted by said conductive element; and

(iv) a current amplifier connected to said conductive surface having a third contact connected to the output of said amplifier;

(d) a coupler attached to said pointer assembly for moving the pointer assembly about said axis.

2. The gauge of claim 1 wherein said conductive element comprises a resilient central conductive arm on the contact plate resiliently engaging said conductive surface.

3. The gauge of claim 1 further defining a cover, the board mounted in the cover, the cover secured to the base to form a fluid tight interior enclosing the pointer assembly, contact plate and board.

4. The gauge of claim 1 wherein the voltage regulator produces a constant voltage output.

5. The gauge of claim 1 wherein the said amplifier has a gain of 1.

6. The gauge of claim 5 wherein said voltage regulator produces a constant voltage output.

7. The gauge of claim 1 wherein said coupler is a magnet.

8. The gauge of claim 3 wherein said coupler is a magnet.