APPARATUS FOR INDICATING THE DENSITY OF A FLUID

• US 3,661,652 A
• Filed: 08/14/1970
• Issued: 05/09/1972
• Est. Priority Date: 08/18/1969
• Status: Expired due to Term

• Current Assignee: Gerard Uitenbroek
• Original Assignee: Gerard Uitenbroek
• Inventors: Uitenbroek, Gerard
• Primary Examiner(s): Walton, Donald L.
• Application Number:
  US05/063,860
• Time in Patent Office: 634 Days
• Field of Search: 136/182 73/30,32,444,445,453
• US Class Current: 429/90
• 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

Density indicating apparatus comprises a guide member, a fixed magnet at one end of the guide member, a movable magnet movable up and down the guide member and a detector for detecting changes in position of the movable magnet. The two magnets are arranged one above the other so as to repel each other so that when immersed in a fluid, the second magnet takes up a position dependent on its weight, the magnetic forces acting on it and the buoyancy force due to displaced fluid.

Claims

1. Apparatus for use in indicating the density of a fluid which apparatus includes a guide member, a first magnet fixed in position relative to the guide member, a second magnet movable up and down the guide member, and means for detecting changes in the position of the second magnet relative to the first magnet, the two magnets being arranged one above the other So as to repel each other and the guide member being adapted to be immersed in a fluid so that the second magnet is submerged in the fluid and takes up a position in equilibrium dependent on its weight, the magnetic forces acting on it, and the buoyancy force due to displaced fluid.

2. Apparatus as claimed in claim 1 in which the first magnet is secured to the guide member below the second magnet.

3. Apparatus as claimed in claim 1 in which the first magnet is secured to the guide member above the second magnet.

4. Apparatus as claimed in claim 2 in which a third magnet is provided in repulsion with the second magnet and fixed in position above the second magnet.

5. Apparatus as claimed in claim 1 in which the guide member comprises a hollow tube within which the second magnet is slidably mounted.

6. Apparatus as claimed in claim 5 in which the second magnet is cylindrical and is magnetized in the direction of its longitudinal axis.

7. Apparatus as claimed in claim 1 in which the second magnet comprises an annular member and the guide member extends through a central aperture in the second magnet.

8. Apparatus as claimed in claim 7 wherein the second magnet is magnetized in annular domains to provide north and south magnetic poles providing a lateral magnetic field.

9. Apparatus as claimed in claim 1 wherein the second magnet is encapsulated in the lower part of a capsule of plastics material thereby providing the magnet with a required degree of buoyancy in a fluid whose density is to be indicated.

10. Apparatus as claimed in claim 9 in which the capsule of plastics material includes a float chamber to provide the required buoyancy.

11. Apparatus as claimed in claim 1 including a reed switch arranged to be operated according to the position of the second magnet relative to the first magnet in order to detect changes in the relative positions of the magnet and provide an indication of the density of the fluid.

12. Apparatus as claimed in claim 1 in which more than one movable magnet is provided and arranged to move up and down the guide means, each movable magnet being arranged to repel the adjacent magnet.

13. A lead acid electric battery including apparatus as claimed in claim 1 mounted in the battery with the guide member extending substantially vertically, for measuring the density of electrolyte within the battery.

14. A lead acid electric battery as claimed in claim 13 in which the guide member comprises a tubular container having holes passing through its walls which are large enough to allow electrolyte to pass through but not large enough to allow battery gases to pass into the container.