Fuel oil level measuring apparatus

• US 4,084,436 A
• Filed: 12/01/1975
• Issued: 04/18/1978
• Est. Priority Date: 12/01/1975
• Status: Expired due to Term

• Current Assignee: RTR, Inc.
• Original Assignee: RTR, Inc.
• Inventors: Smitherman, Ray C.
• Primary Examiner(s): Queisser, Richard C.
• Assistant Examiner(s): Appleman, John S.
• Application Number:
  US05/636,758
• Time in Patent Office: 869 Days
• Field of Search: 73/313, 73/DIG. 5, 73/311, 324/29.5
• US Class Current: 73/313
• CPC Class Codes: G01F 23/70 for sensing changes in level only at discrete points
• CPC Class Codes: Y10S 73/05 Liquid levels with magnetic transmission

Abstract

An apparatus for indicating the level of fuel in a fuel oil storage tank including a vertically positioned tube having a multiplicity of longitudinally spaced and movable floats therein and a multiplicity of associated reed switches and resistors positioned on the outside of the tube and spaced from each other. The switches are actuated by magnets on the associated floats, which rise and fall with the fuel level, and shunt varying amounts of current by the resistors so that a fuel level readout can be obtained on a meter.

Claims

1. An apparatus for indicating the level of fuel oil in a fuel oil storage tank, said apparatus comprising:

a substantially vertically extending substantially straight conduit;

a plurality of stop means, each of said stop means extending inwardly from the interior wall of said conduit, said stop means being spaced from each other along said conduit;

a plurality of floats positioned in said conduit, each float being positioned between a respective pair of next adjacent ones of said plurality of said stop means;

a plurality of magnets each of which is mounted on a respective one of said floats;

a plurality of reed switches electrically connected in series to each other, each of said reed switches being mounted on the exterior of said conduit immediately adjacent and having a portion vertically coextensive with a respective one of said stop means;

a plurality of resistors electrically connected in series to each other, each of said resistors being electrically in parallel with a respective one of said plurality of reed switches; and

a meter electrically connected to said reed switches and said resistors so that as the level of fuel oil in a fuel oil storage tank in which said conduit is positioned, rises, each of said floats and magnets thereon successively, from the lowermost to the uppermost, rises and actuates the reed switch adjacent one of the two stop means between which it is positioned whereby said meter can indicate that the level of fuel oil is adjacent that reed switch and as the level of fuel oil falls, each of said floats and magnets thereon successively, from the uppermost to the lowermost, falls and deactuates the reed switch adjacent one of the two stop means between which it is positioned whereby said meter can indicate that the level of fuel oil is no longer adjacent that reed switch.

2. An apparatus as claimed in claim 1, wherein each of said resistors is mounted adjacent a respective one of said plurality of stop means.

3. An apparatus for indicating the level of fuel oil in a fuel oil storage tank, said apparatus comprising:

a substantially vertically extending substantially straight conduit;

a plurality of stop means, each of said stop means extending inwardly from the interior wall of said conduit, said stop means being spaced from each other along said conduit;

a plurality of vertically extending floats positioned in said conduit, each float being positioned between a respective pair of next adjacent ones of said plurality of stop means;

a plurality of magnets, each of which is mounted on the upper end of a respective one of said floats;

a plurality of normally open reed switches electrically connected in series to each other, each of said reed switches being mounted on the exterior of said conduit immediately adjacent and having a portion vertically coextensive with a respective one of said stop means;

a plurality of resistors electrically connected in series to each other, each of said resistors being mounted on the exterior of said conduit immediately adjacent a respective one of said stop means, each of said resistors being electrically connected in parallel with a respective one of said plurality of reed switches; and

a meter electrically connected to said reed switches and said resistors so that as the level of the fuel oil, in an oil storage tank in which said conduit is positioned, rises, each of said floats and magnets thereon successively, from the lowermost to the uppermost, rises and is stopped by the uppermost one of the pair of stop means between which it is positioned and closes the respective reed switch adjacent that stop means whereby said meter can indicate that the level of fuel oil is adjacent that reed switch and as the level of fuel falls, each of said floats and magnets thereon successively, from the uppermost to the lowermost, falls away from the uppermost one of the pair of stop means between which it is positioned and opens the respective reed switch adjacent that stop means whereby said meter can indicate that the level of fuel oil is no longer adjacent that reed switch.

4. An apparatus for indicating the level of fuel oil in a fuel oil storage tank, said apparatus comprising:

a substantially vertically extending substantially straight tube;

a plurality of stop means, each of said stop means extending inwardly from the interior wall of said tube, said stop means being spaced along said tube;

a plurality of vertically extending floats of a cross section substantially equal to but of slightly less diameter than that of the tube, each float being positioned between a respective pair of next adjacent ones of said plurality of stop means;

a plurality of magnets of annular cross section substantially equal to that of said floats, each of said magnets being mounted on the upper end of a respective one of said floats;

a plurality of normally open reed switches electrically connected in series to each other, each of said reed switches being mounted on the exterior of the said tube immediately adjacent and having a portion vertically coextensive with a respective one of said stop means;

sealant means for hermetically sealing each of said reed switches against contact of fluid therewith;

a plurality of resistors electrically connected in series to each other, each of said resistors being mounted on the exterior of said tube immediately adjacent and having a portion vertically coextensive with a respective one of said stop means, each of said resistors being electrically connected in parallel with a respective one of said plurality of reed switches; and

a meter electrically connected to said reed switches and said resistors so that as the level of fuel oil in an oil storage tank in which said tube is positioned, rises, each of said floats and magnets thereon successively, from the lowermost to the uppermost, rises and is stopped by the uppermost one of the pair of stop means between which it is positioned and closes the respective reed switch adjacent that stop means, whereby said meter can indicate that the level of fuel oil is adjacent that reed switch, and as the level of oil falls each of said floats and magnets thereon successively, from the uppermost to the lowermost, falls away from the uppermost one of the pair of stop means between which it is positioned and opens the respective reed switch which is adjacent that stop means, whereby said meter can indicate that the level of fuel oil is no longer adjacent that reed switch.

5. An apparatus as claimed in claim 4, wherein each of said stop means comprises a pin which extends completely traversely across the interior of said tube.

6. An apparatus as claimed in claim 4, wherein each of said plurality of resistors is positioned immediately adjacent the respective one of said plurality of reed swtiches with which that resistor is electrically connected in parallel.

7. An apparatus as claimed in claim 4, wherein each of said resistors has a resistance less than the resistance of any of the other resistors which are more remote from the upper end of the tube than that resistor.