WO2012142086A1

WO2012142086A1 - Battery condition indicator

Info

Publication number: WO2012142086A1
Application number: PCT/US2012/033018
Authority: WO
Inventors: Mark J. Summer
Original assignee: Illinois Tool Works Inc.
Priority date: 2011-04-12
Filing date: 2012-04-11
Publication date: 2012-10-18

Abstract

A battery condition indicator includes a cage defining a channel, and a ball float in the channel. The channel is defined by adjacent surfaces having curved transitions therebetween to reduce areas of stagnant fluid in the channel.

Description

BATTERY CONDITION INDICATOR

CROSS-REFERENCE TO RELATED APPLICATIONS

[01] The present application claims the benefits of United States Provisional

Application Serial No. 61/474,380 filed April 12, 2011.

FIELD OF THE INVENTION

[02] The present invention relates generally to hydrometers and fluid level sensors and charge indicators that exhibit the condition of a battery, and more specifically to in-battery battery condition indicators.

BACKGROUND OF THE INVENTION

[03] Battery condition indicators are used in storage batteries of many types, including those installed in motor vehicles. Known battery state of charge indicators function as hydrometers detecting changes in the specific gravity of the electrolyte in the battery, which is indicative of the electrical charge condition of the battery, and provide a visual indication of the charge condition. Battery state of charge indicators also can detect changes in the electrolyte level in the battery and provide a visual indication if the electrolyte level is below a predetermined minimum level. It is known to provide both state of charge condition and electrolyte level detection functions in the same battery condition indicator.

[04] It is known to provide a battery condition indicator with a cage intended to be submerged in the electrolyte of the battery. The cage defines an angularly oriented channel and includes a ball float that is intended to move freely within the channel, the channel being open to liquid migration of the electrolyte in the battery. The ball float is of a specific density, and a change in the density of the liquid in the channel causes the ball float to rise or sink in the channel. Accordingly, the position of the ball float changes in relation to changes in the density of the liquid. These changes can be monitored to indicate a charge state of the battery. For accurate performance of the indicator, liquid migration is allowed through the indicator cage, which requires liquid flow past the ball float at any location along the channel. Further, as the ball moves in the channel in response to changing battery conditions, the liquid within the channel should flow easily past the ball in any direction. A known battery condition indicator is inserted in an opening through the cover for the cell of a battery and provides a head with a visual window for looking into the battery. If the battery is adequately filled, the cage or box is immersed in the fluid electrolyte.

[05] More than one ball float can be used, with each of the two or more balls being responsive to a different battery condition to rise or fall in the channel or channels. A light transmissive rod extends between the head of the indicator and the cage with the floatable bodies. A conical tip at the end of the light- transmissive rod has a tip adjacent the channels in which the one or more floatable bodies move. The floatable bodies are of different colors to provide different visual cues when visible through the indicator. A battery condition indicator having one floatable body can provide visual cues for a satisfactorily charged battery with satisfactory electrolyte level, a different visual cue for a satisfactory electrolyte level but a low battery charge and a third cue if the electrolyte level is low. By providing more floatable bodies responsive to different specific gravities, low fluid level can be indicated as well as low, fair and satisfactory electric charge.

[06] In known indicators of this type, the channel or channels have been substantially rectangular in cross-sectional shape. Turbulence is created in the liquid as the ball float moves and liquid flows past the ball float. However, liquid in the regions of the channel that are more distant from the ball float tends to stagnate, and it has been observed that contaminants or bubbles can accumulate in the stagnant areas. The accumulation of bubbles or contaminants can hinder free movement of the ball float within the channel, resulting in inaccurate readings of the battery condition due to incorrect correlation between the ball float position and the density of the liquid. SUMMARY OF THE INVENTION

[07] The battery condition indicator disclosed herein defines an angular channel with reduced stagnant area, so that the accumulation of contaminants and/or bubbles is reduced.

[08] In one aspect of one form thereof, a response assembly for a battery condition indicator is provided with a cage defining a channel therein and a floatable body disposed in the channel. The channel is defined by a channel bottom, a channel top and opposed channel sides. Curved transition surfaces are provided between adjacent surfaces of the channel bottom, the channel top and the channel sides.

[09] In another aspect of a form thereof, a battery condition indicator is provided with a light transmissive body, a cage attached to one end of the light transmissive body, the cage defining a channel therein, and a floatable body disposed in the channel. The channel is defined by a channel bottom, a channel top and opposed channel sides. Curved transition surfaces are provided between adjacent surfaces of the channel bottom, the channel top and the channel sides.

[10] In a further aspect of a form thereof, a battery condition indicator is provided with a light transmissive body; a cage attached to one end of the light transmissive body, the cage defining an angular channel; and a floatable body disposed in the channel. The channel is defined by adjacent channel surfaces, and curved transition surfaces are provided between the adjacent channel surfaces.

[11] Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings in which like numerals are used to designate like features.

BRIEF DESCRIPTION OF THE DRAWINGS

[12] Fig. 1 is a perspective view of a battery condition indicator; [13] Fig. 2 is a cross-sectional view of a battery condition indicator installed in a battery; and

[14] Fig. 3 is a further cross-sectional view of a battery condition indicator.

[15] Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use herein of "including", "comprising" and variations thereof is meant to encompass the items listed thereafter and equivalents thereof, as well as additional items and equivalents thereof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[16] Referring now more specifically to the drawings and to Fig. 1 in particular, numeral 10 designates a battery condition indicator, and, more specifically, a battery electrolyte condition indicator which can be installed in a battery 12 (Fig. 2). Indicators of the type to be described can be used in vessels or containers other than lead/acid storage batteries, although the use in such batteries is an advantageous use of the present invention. Indicator 10 can be used to detect fluid level changes in a variety of containers or vessels and also may be used to detect changes in other fluid conditions.

[17] Indicator 10 includes a response assembly 14 at one end of a light transmissive body 16 having a head 18 at the end opposite response assembly 14. Response assembly 14 is connected to light transmissive body 16 and includes a cage or box 20 defining a channel 22 containing a floatable body 24. Channel 22 is angularly oriented between a lower end and a higher end thereof. Channel 22 allows floatable body 24 to rise or fall in fluid in which it is immersed, depending on the specific gravity of the fluid and the surface level of the fluid. As known to those skilled in the art, floatable body 24 moves along channel 22 in response to changing conditions of a fluid in which it is placed, as the floatable body rises or falls in the liquid. Changes in the position of floatable body 24 relative to light transmissive body 16 cause changes in what an observer can see when looking through head 18 into light transmissive body 16.

[18] Indicator 10 is installed in battery 12 with a mounting collar or ring 26 generally around and below head 18, to securely engage indicator 10 within a hole in the case of battery 12.

[19] Light transmissive body 16, as best seen in Fig. 2, is a rod-like monolithic body having a conical tip 30 within cage 20. Light transmissive body 16 is formed of a light transmitting material such as, for example, acrylic, glass, styrene or other clear, partially clear or tinted material. As known to those skilled in the art, floatable body 24 moves along channel 22 in response to changing conditions of a fluid in which it is placed. In response to pre-established changes in specific gravity of the liquid, floatable body 24 may be adjacent conical tip 30 or distant therefrom. When floatable body 24 is distant from conical tip 30, the color of floatable body 24 is not visible through head 18, indicating that the specific gravity of the fluid in which response assembly 14 is placed has fallen below the pre-established level. If the fluid level is below the level of channel 22, floatable body 24 is again remote from conical tip 30. However, since conical tip 30 is not then submerged in the fluid, conical tip 30 becomes reflective, and the view through head 18 is bright and clear, indicating that the fluid level is below the pre-established level. If the fluid level is sufficiently high and the specific gravity is sufficiently great to float floatable body 24 and position floatable body 24 adjacent conical tip 30, the view through head 18 is a bright view of the color of floatable body 24. As those skilled in the art will understand readily, multiple floatable bodies of different colors and responsive to different conditions can be used to indict differing battery conditions. The color of cage 20, the tint of light transmissive body 16, as well as the colors of floatable bodies, all influence the image seen through head 18, depending on the fluid level and fluid condition, thereby influencing the locations of floatable bodies. [20] Indicator head 18 defines a window for peering into indicator 10. Head

18 can be a single piece of clear plastic or the like and can be formed as a monolithic body with light transmissive body 16.

[21] Cage 20 includes a base 40, opposed end walls 42, 44 and opposed sides

46, 48. An angularly oriented channel bottom 50 and an angularly oriented channel top 52 together with opposed sides 46, 48 define angular channel 22. Opposed sides 46, 48 are spaced, generally perpendicular bodies defining planes that are at right angles to both channel bottom 50 and channel top 52. Channel bottom 50 and channel top 52 are substantially parallel bodies. It should be understood that sides 46, 48, bottom 50 and/or top 52 are discontinuous along the length of channel 22, to provide openings or spaces along cage 20 for the free flow of fluid into, out of and through channel 22. Curved transitions 54, 56 are provided along adjacent extents of opposed sides 46, 48 with channel bottom 50 and/or channel top 52. Curved transitions 54, 56 are of sufficient size and curvature to reduce static areas that otherwise would exist in fluid filling channel 22. In a preferred arrangement, as viewed in the cross sectional plane shown in Fig. 3, the maximum radial distance from the center of channel 22 to either of curved transitions 54 or 56 is not greater than about 130% of the minimum radial distance from the center point of channel 22 to channel top 52 or channel bottom 50, and is not less than about equal to the minimum radial distance from the center point of channel 22 to either of channel top 52 or channel bottom 50.

[22] Curved transitions 54, 56 minimize dead areas in the channel and provide more consistent spacing between floatable body 24 and adjacent surfaces of the channel, and therefore more consistent fluid velocities are provided around floatable body 24, thereby more closely equalizing external influences on the movement of floatable body 24. Accordingly, as floatable body 24 moves within channel 22, turbulence that is created in a liquid flowing past floatable body 24 reaches the boundaries of channel 12 more consistently, thereby dislodging and moving contaminants or bubbles that otherwise might accumulate. Potentially stagnant areas are minimized, and performance and accuracy of the indicator are increased since movement of the floatable body is not hindered by accumulated contaminants or bubbles.

[23] While shown and described herein for use and application in a vehicle battery, it should be understood that the present invention also can be used for other types of fluid containers requiring the installation and sealing of an indicator or insert of some type. Use for vehicle batteries is merely one advantageous application of the present invention.

[24] Variations and modifications of the foregoing are within the scope of the present invention. It is understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present invention. The embodiments described herein explain the best modes known for practicing the invention and will enable others skilled in the art to utilize the invention. The claims are to be construed to include alternative embodiments to the extent permitted by the prior art.

[25] Various features of the invention are set forth in the following claims.

Claims

CLAIMS WHAT IS CLAIMED IS:

1. A response assembly for a battery condition indicator, comprising: a cage defining a channel therein;

a floatable body disposed in said channel;

said channel being defined by a channel bottom, a channel top and opposed channel sides; and

curved transition surfaces between adjacent surfaces of said channel bottom, said channel top and said channel sides.

2. The response assembly for a battery condition indicator of claim 1, said curved transition surfaces defining maximum radial distances to a center point in said channel that is not greater than about 130% of a minimum radial distance from the center point in said channel to said channel top and said channel bottom.

3. The response assembly for a battery condition indicator of claim 2, at least some of said channel bottom, channel top and opposed channel sides being discontinuous along a length of said channel.

4. The response assembly for a battery condition indicator of claim 2, said channel being angularly disposed in said cage.

5. The response assembly for a battery condition indicator of claim 2, said channel being further defined by end walls on opposite ends of said channel.

6. The response assembly for a battery condition indicator of claim 5, said channel being angularly disposed in said cage.

7 The response assembly for a battery condition indicator of claim 1, said channel being angularly disposed in said cage.

8. The response assembly for a battery condition indicator of claim 1, said channel being further defined by end walls on opposite ends of said channel.

9. A battery condition indicator, comprising:

a light transmissive body;

a cage attached to one end of said light transmissive body, said cage defining a channel therein;

a floatable body disposed in said channel;

10. The battery condition indicator of claim 9, said curved transition surfaces defining maximum radial distances to a center point in said channel that is not greater than about 130% of a minimum radial distance from the center point in said channel to said channel top and said channel bottom.

11. The battery condition indicator of claim 10, at least some of said channel bottom, channel top and opposed channel sides being discontinuous along a length of said channel.

12. The battery condition indicator of claim 10, said channel being angularly disposed in said cage.

13. The battery condition indicator of claim 10, said channel being further defined by end walls on opposite ends of said channel.

14. The battery condition indicator of claim 9, said channel being angularly disposed in said cage.

15. The battery condition indicator of claim 9, said channel being further defined by end walls on opposite ends of said channel.

16. A battery condition indicator, comprising:

a light transmissive body;

a cage attached to one end of said light transmissive body, said cage defining an angular channel;

a floatable body disposed in said channel;

said channel being defined by adjacent channel surfaces; and

curved transition surfaces between said adjacent channel surfaces.

17. The battery condition indicator of claim 16, at least some of said adjacent channel surfaces being discontinuous along a length of said channel.

18. The battery condition indicator of claim 17, said channel being further defined by end walls on opposite ends of said channel

19. The battery condition indicator of claim 16, said channel being further defined by end walls on opposite ends of said channel.

20. The battery condition indicator of claim 16, said curved transition surfaces defining maximum radial distances to a center point in said channel that is not greater than about 130% of a minimum radial distance from the center point in said channel to said adjacent channel surfaces.