Remote battery cell specific gravity and electrolytic level monitor using floats and optical couplers

• US 4,866,428 A
• Filed: 03/08/1988
• Issued: 09/12/1989
• Est. Priority Date: 03/08/1988
• Status: Expired due to Fees

• Current Assignee: Illinois Tool Works Inc.
• Original Assignee: Illinois Tool Works Inc.
• Inventors: Hinkle, Jay L.
• Primary Examiner(s): Orsino, Joseph A.
• Assistant Examiner(s): Jackson, Jill D.
• Application Number:
  US07/165,624
• Time in Patent Office: 553 Days
• Field of Search: 340/636, 340/619, 340/624, 73/32 R, 73/447, 73/293, 73/311, 73/314, 73/306, 73/307, 73/308, 73/327, 324/432, 324/434, 116/227, 250/231 R, 250/222.1, 320/48
• US Class Current: 340/636.1
• CPC Class Codes: G01F 23/2921 for discrete levels
• CPC Class Codes: G01N 9/14 the body being built into a container
• CPC Class Codes: G01N 9/18 Special adaptations for indicating, recording, or control
• CPC Class Codes: H01M 10/484 for measuring electrolyte level, electrolyte density or electrolyte conductivity
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A system and sensor for remotely monitoring the state of the condition of the electrolyte within each of the battery cells of a power supply is disclosed. The system includes a sensor having a dual ball-float and track arrangement for shuttering a pair of light sources and so as to independently detect and differentiate predetermined low electrolyte specific gravity and a low level of the electrolyte. Two multiplexing units receive the sensor signals and display separate indications of each battery and the states detected. The detector uses a gravity responsive ball disposed within a track that shutters one light source at a predetermined low specific gravity and a second level responsible ball within a second track located above the gravity track and ball. The level ball has a specific gravity which is less than that of the specific gravity responsive ball and shutters the second light source at a predetermined low electrolyte level independently of changes in the specific gravity of the electrolyte.

Claims

1. A system for remotely monitoring the state of the condition of the electrolyte within each one of a plurality of batteries defining a power source, comprising:

a plurality of sensor means, one sensor means being associated with each battery of said plurality of batteries, for simultaneously and independently sensing and differentiating between a predetermined low level of said electrolyte within each one of said batteries and a predetermined low specific gravity value of said electrolyte disposed within each one of said batteries, and for independently generating a first electrical signal responsive to said predetermined low specific gravity value of said electrolye disposed within each one of said batteries, and a second electrical signal responsive to said predetermined low level of said electrolyte disposed within each one of said batteries, wherein each one of said plurality of sensor means includes;

(a) probe means mounted upon said associated battery and having a portion thereof immersed within said electrolyte of said associated battery;

(b) a first ball track defined within said portion of said probe means immersed within said electrolyte of said associated battery;

(c) a first ball disposed within said first ball track and having a predetermined specific gravity value such that said first ball will be disposed at a predetermined position within said first ball track when the specific gravity of said electrolyte disposed within said associated battery achieves a predetermined low specific gravity value;

(d) a second ball track defined within said portion of said probe means immersed within said electrolyte of said associated battery and disposed above said first ball track;

(e) a second ball disposed within said second ball track and having a predetermined specific gravity value which is less than that of said first ball such that said second ball is substantially independent of said specific gravity value of said electrolye disposed within said associated battery and is responsive to the level of said electrolyte disposed within said associated battery so as to be disposed at a predetermined position within said second ball track when the level of said electrolyte disposed within said associated battery achieves a predetermined low level;

(f) a first light source, for generating a first light beam, and a first light detector, for receiving said first light beam, disposed upon opposite sides of said first ball track at said predetermined position defining said low specific gravity value of said electrolyte disposed within said associated battery so as to generate said first electrical signal, indicative of said low specific gravity value of said electrolyte disposed within said associated battery, when said first ball is disposed at said predetermined position within said first ball track and is therefore interposed between said light source and said first light detector so as to block transmission of said first light beam from said first light source to said first light detector; and

(g) a second light source, for generating a second light beam, and a second light detector, for receiving said second light beam, disposed upon opposite sides of said second ball track at said predetermined position defining said low electrolyte level within said associated battery so as to generate said second electrical signal, indicative of said low electrolyte level within said associated battery, when said second ball is disposed at said predetermined position within said second ball track and is therefore interposed between said second light source and said second light detector so as to block transmission of said second light beam from said second light source to said second light detector; and

electrical circuit means coupled to each one of said plurality of sensor means for receiving said first electrical signal and said second electrical signal from each one of said plurality of sensor means, for generating separate low electrolyte level and low specific gravity value alarm signals in response to each one of said first electrical signals and said second electrical signals, and for indicating which one of said plurality of batteries is associated with said first and second electrical signals received.

2. The system as defined in claim 1 wherein said circuit means includes a first multiplex unit coupled to said sensor means and adapted to receive said first electrical signals from each one of said sensor means and to generate said low electrolyte level alarm signals and a second multiplex unit coupled to said sensors and adapted to receive said second electrical signals from each one of said sensor means and to and generate said low specific gravity alarm signals.

3. The system as defined in claim 2 wherein said first multiplex unit includes a first alarm output electrically coupled to a remote access system of a telephone system and said second multiplex unit includes a second alarm output electrically coupled to said remote access system of said telephone system.

4. A sensor for sensing the state of the condition of an electrolyte disposed within a battery cell, comprising:

a body having opposite ends wherein one end of said body is adapted to be mounted upon said battery within a opening leading into said battery cell;

a substantially elongated probe mounted coaxially with respect to said body and extending from said one end, and including means mounted proximate to a free end of said probe for simultaneously, independently detecting and differentiating between a predetermined low level of said electrolyte and a predetermined low specific gravity value of said electrolyte disposed within said battery cell; and

means for adjusting the axial position of said detecting and differentiating means relative to said one end of said body between a fully retracted position and a fully extended position.

5. The sensor as defined in claim 4 wherein said means for adjusting the axial position of said means for detecting includes means for adjusting the axial position of said probe relative to said body.

6. The sensor as defined in claim 5 wherein said body is substantially hollow having an opening in said one end, said probe being axially, slidably mounted in said opening between said fully retracted position and said fully extended position and means for releasably retaining said probe at said fully retracted position, at said fully extended position and at a plurality of intermediate positions between said fully retracted position and said fully extended position.

7. The sensor as defined in claim 6 wherein said means for releasably retaining said probe includes a plurality of axially spaced apart substantially diametrically opposed radially inwardly extending flexible fins on an inner wall of said body and a substantially annular radially outwardly facing groove on an outer surface of said probe proximate an end of said probe opposite said free end, said fins serially receivable in said groove and adapted to axially deflect and disengage from said groove upon application of an axial force to said probe.

8. The sensor as defined in claim 7 including an adjustment sleeve disposed within said body said adjustment sleeve includes said flexible fins.

9. The sensor as defined in claim 8 wherein said probe is tubular and closed at said free end by said means for detecting and differentiating and closed at said end opposite said free end by a collar, said collar including said groove.

10. The sensor as defined in claim 9 wherein said first track and said second track are inclined to the longitudinal axis of said probe.

11. The sensor as defined in claim 9 wherein said means for detecting and differentiating includes ball and track means mounted upon said probe for submersion in said electrolyte in an installed position of said sensor including a first track, a first ball mounted for movement in said first track said first ball having a predetermined specific gravity so as to have a predetermined buoyancy in said electrolyte at a predetermined specific gravity of said electrolyte, a second track located at a higher axial position than said first track in said installed position, a second ball mounted for movement in said second track, said second ball having a predetermined specific gravity less than the specific gravity of said first ball and two pair of aligned light sources and light detectors one pair mounted on opposite sides of said first track at a predetermined axial position, the second pair mounted on opposite sides of said second track at a predetermined axial position, whereby each one of said balls makes and breaks the light path between said respective light sources and detectors as a function of changes in specific gravity and level of said electrolyte.

12. The sensor as defined in claim 11 wherein the specific gravity of said first ball is in the range of about 1.185 to 1.300 and the specific gravity of said second ball is in the range of about 0.001 and 1.180.

13. A sensor for sensing the state of the condition of an electrolyte within a battery cell, comprising:

probe means mounted upon said battery cell and having a portion thereof immersed within said electrolyte of said battery cell;

a first ball track defined within said portion of said probe means immersed within said electrolyte of said battery cell;

a first ball disposed within said first ball track and having a predetermined specific gravity value such that said first ball will be disposed at a predetermined position within said first ball track when the specific gravity of said electrolyte achieves a predetermined low specific gravity value;

a second ball track defined within said portion of said probe means immersed within said electrolyte of said battery cell and disposed above said first ball track;

a second ball disposed within said second ball track and having a predetermined specific gravity value which is less than that of a said first ball such that said second ball is substantially independent of said specific gravity value of said electrolyte disposed within said battery cell and is reponsive to the level of said electrolyte disposed within said battery cell so as to be disposed at a predetermined position within said second ball track when the level of said electrolyte disposed within said battery cell achieves a predetermined low level;

a first light source, for generating a first light beam, and a first light detector, for receiving said first light beam, disposed upon opposite sides of said first ball track at said predetermined position defining said low specific gravity value of said electrolyte so as to generate a first signal, indicative of said low specific gravity value of said electrolyte disposed within said battery cell, when said first ball is disposed at said predetermined position within said first ball track and is therefore interposed between said first light source and said first light detector so as to block transmission of said first light beam from said first light source to said first light detector; and

a second light source, for generating a second light beam, and a second light detector, for receiving said second light beam, disposed upon opposite sides of said second ball track at said predetermined position defining said low electrolyte level within said battery cell so as to generate a second signal, indicative of said low electrolyte level within said battery cell, when said second ball is disposed at said predetermined position within said second ball track and is therefore interposed between said second light source and said second light detector so as to block transmission of said second light beam from said second light source to said second light detector.

14. A sensor as set forth in claim 13, wherein:

said probe means comprises a substantially hollow, tubular probe.

15. A sensor as set forth in claim 14, furth comprising:

means for electrically connecting said first and second light sources, and said first and second light detectors, to an external circuit.

16. The sensor as defined in claim 15, wherein:

said means for electrically connecting said first and second light sources, and said first and second light detectors, to an external circuit includes a printed circuit board mounted within said hollow probe, said first and second light sources and said first and second light detectors being mounted upon said printed circuit board.

17. A sensor as set forth in claim 13, further comprising:

a substantially hollow, tubular body including means for mounting said body within an opening defined within said battery cell; and

means for mounting said probe means substantially coaxially upon said body.

18. The sensor as defined in claim 17 wherein the probe is axially adjustable relative to said body.

19. The sensor as defined in claim 18 wherein the specific gravity of said first ball is at least 1.185 and the specific gravity of said second ball is not greater than 1.180.

20. The sensor as defined in claim 19 wherein the specific gravity of said second ball is 1.104.