Multi-axis bubble vial device

• US 7,497,021 B2
• Filed: 01/24/2006
• Issued: 03/03/2009
• Est. Priority Date: 01/24/2006
• Status: Active Grant

• Current Assignee: Trimble Navigation Limited (Trimble Inc.)
• Original Assignee: Trimble Navigation Limited (Trimble Inc.)
• Inventors: McCarty, Robin Gwen, Perchak, Robert M.
• Primary Examiner(s): SMITH, RICHARD A
• Application Number:
  US11/338,051
• Publication Number:
  US 20070169362A1
• Time in Patent Office: 1,134 Days
• Field of Search: 333/661.1, 333/661.2, 333/661.4, 333/661.5, 333/661.6, 333/662.3, 333/79, 359/139.1
• US Class Current: 33/366.16
• CPC Class Codes: G01C 9/06 Electric or photoelectric indication or reading means
• CPC Class Codes: G01C 9/26 Details
• CPC Class Codes: G01C 9/36 of the spherical type, i.e. for indicating the level in all directions

Abstract

A multi-axis bubble vial device includes a bubble vial having a vial body defining a fluid chamber with a curved upper surface, and a quantity of fluid partially filling the chamber. The fluid defines a bubble in the upper portion of the chamber that moves along the upper surface in dependence upon the orientation of the vial. A centrally positioned light source above the bubble vial directs light into the chamber, and four light sensors, positioned above the bubble vial and arranged circumferentially around the centrally positioned light source, detect the reflection of light from a reflector beneath the fluid chamber. A first pair of the sensors is positioned on opposite sides of the light source along a first axis, and a second pair of the sensors is positioned on opposite sides of the light source along a second axis. The second axis is substantially perpendicular to the first axis.

Claims

1. A multi-axis bubble vial device, comprising:

a bubble vial having a vial body defining a fluid chamber with a curved upper surface,

a quantity of fluid partially filling said chamber, said fluid defining a bubble in the upper portion of said chamber which moves along said upper surface in dependence upon the orientation of said vial,

a centrally positioned light source above said bubble vial directing light into said chamber,

four light sensors positioned above said bubble vial and arranged circumferentially around said centrally positioned light source, a first pair of said sensors being positioned on opposite sides of said light source along a first axis, and a second pair of said sensors being positioned on opposite sides of said light source along a second axis, said second axis being substantially perpendicular with respect to said first axis, and

a reflector beneath said fluid chamber, such that light emitted from said light source passes through said bubble and said fluid and is reflected by said reflector to said light sensors, whereby the relative levels of light detected by said first pair of sensors indicates the orientation of said first axis with respect to horizontal, and the relative levels of light detected by said second pair of sensors indicates the orientation of said second axis with respect to horizontal.

2. The multi-axis bubble vial device of claim 1 in which said reflector comprises a mirrored reflector positioned beneath said bubble vial.

3. The multi-axis bubble vial device of claim 2 in which said reflector comprises a mirror having a reflective surface, said mirror being adhesively secured to said bubble vial by an adhesive having a refractive index which is substantially the same as the refractive index of the material from which said bubble vial is made.

4. The multi-axis bubble vial device of claim 1 in which said reflector comprises a reflective coating in said fluid chamber on the surface of said chamber opposite to said curved surface.

5. The multi-axis bubble vial device of claim 4 in which said surface opposite said curved surface is substantially flat.

6. The multi-axis bubble vial device of claim 1 in which said centrally positioned light source comprises a light emitting diode.

7. The multi-axis bubble vial device of claim 1 in which each of said four light sensors comprises a photodiode.

8. The multi-axis bubble vial device of claim 1 in which the sides of said fluid chamber between said curved upper surface and said opposite surface are light absorbing, whereby extraneous light reflections are reduced.

9. The multi-axis bubble vial device of claim 8 in which said bubble vial is shielded from extraneous light which might introduce error into the orientations measured for said first and second axes.

10. The multi-axis bubble vial device of claim 1 in which said reflector comprises a reflective coating on the outside, bottom surface of said bubble vial.

11. A multi-axis orientation determination device, comprising:

a bubble vial having a vial body defining a fluid chamber with a curved upper surface,

a quantity of fluid partially filling said chamber, said fluid defining a bubble in the upper portion of said chamber which moves along said upper surface in dependence upon the orientation of said vial,

a centrally positioned light source above said bubble vial directing light into said chamber,

light sensors positioned above said bubble vial and arranged circumferentially around said centrally positioned light source, a first pair of said sensors being positioned on opposite sides of said light source along a first axis, and a second pair of said sensors being positioned on opposite sides of said light source along a second axis, said second axis being substantially perpendicular with respect to said first axis, each of said sensors providing a electrical output signal in dependence upon received light,

a reflector beneath said fluid chamber such that light emitted from said light source passes through said bubble and said fluid and is reflected by said reflector to said light sensors,

a first circuit, responsive to the electrical output signals from said first pair of sensors, for providing an indication of the orientation of said bubble vial in the direction of said first axis from the relative levels of light detected by said first pair of sensors, and

a second circuit, responsive to the electrical output signals from said second pair of sensors, for providing an indication of the orientation of said bubble vial in the direction of said second axis from the relative levels of light detected by said second pair of sensors.

12. The multi-axis bubble vial device of claim 11 in which said reflector comprises a mirrored reflector positioned beneath said bubble vial.

13. The multi-axis bubble vial device of claim 12 in which said reflector comprises a mirror having a reflective surface, said mirror being adhesively secured to said bubble vial by an adhesive having a refractive index which is substantially the same as the refractive index of the material from which said bubble vial is made.

14. The multi-axis bubble vial device of claim 11 in which said reflector comprises a reflective coating in said fluid chamber on the surface of said chamber opposite to said curved surface.

15. The multi-axis bubble vial device of claim 14 in which said surface opposite said curved surface is substantially flat.

16. The multi-axis bubble vial device of claim 11 in which said centrally positioned light source comprises a light emitting diode.

17. The multi-axis bubble vial device of claim 11 in which each of said light sensors comprises a photodiode.

18. The multi-axis bubble vial device of claim 11 in which the sides of said fluid chamber between said curved upper surface and said opposite surface are light absorbing, whereby extraneous light reflections are reduced.

19. The multi-axis bubble vial device of claim 18 in which said bubble vial is shielded from extraneous light which might introduce error into the orientations measured for said first and second axes.

20. The multi-axis bubble vial device of claim 11 in which said reflector comprises a reflective coating on the outside, bottom surface of said bubble vial.

21. A bubble vial device, comprising:

a bubble vial having a vial body defining a fluid chamber with a curved upper surface,

a quantity of fluid partially filling said chamber, said fluid defining a bubble in the upper portion of said chamber which moves along said upper surface in dependence upon the orientation of said vial,

a centrally positioned light source above said bubble vial directing light into said chamber,

a plurality of sensors positioned above said bubble vial and arranged circumferentially around said centrally positioned light source,

a reflector beneath said fluid chamber, such that light emitted from said light source passes through said bubble and said fluid and is reflected by said reflector to said light sensors, whereby the relative levels of light detected by said sensors indicates the orientation of said bubble vial device.

22. The bubble vial device of claim 21 in which said reflector comprises a mirrored reflector positioned beneath said bubble vial.

23. The bubble vial device of claim 22 in which said reflector comprises a mirror having a reflective surface, said mirror being adhesively secured to said bubble vial by an adhesive having a refractive index which is substantially the same as the refractive index of the material from which said bubble vial is made.

24. The bubble vial device of claim 21 in which said reflector comprises a reflective coating in said fluid chamber on the surface of said chamber opposite to said curved surface.

25. The bubble vial device of claim 24 in which said surface opposite said curved surface is substantially flat.

26. The bubble vial device of claim 21 in which said centrally positioned light source comprises a light emitting diode.

27. The bubble vial device of claim 21 in which each of said light sensors comprises a photodiode.

28. The bubble vial device of claim 21 in which the sides of said fluid chamber between said curved upper surface and said opposite surface are light absorbing, whereby extraneous light reflections are reduced.

29. The bubble vial device of claim 28 in which said bubble vial is shielded from extraneous light which might introduce error into the orientations measured for said first and second axes.

30. The bubble vial device of claim 21 in which said reflector comprises a reflective coating on the outside, bottom surface of said bubble vial.

31. The bubble vial device of claim 21 in which said plurality of sensors positioned above said bubble vial are substantially equally spaced circumferentially, and in which said plurality of sensors includes an odd number of sensors.

32. The bubble vial device of claim 31 in which said plurality of sensors comprises three sensors.

33. The bubble vial device of claim 21 in which said plurality of sensors positioned above said bubble vial are substantially equally spaced circumferentially, in which said plurality of sensors includes an even number of sensors, and in which said plurality of sensors is grouped into a plurality of pairs of sensors.