Inclination sensor

• US 6,499,220 B2
• Filed: 09/09/1999
• Issued: 12/31/2002
• Est. Priority Date: 12/09/1997
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Nakagaki, Toshiya, Ushihara, Masaharu, Katsuki, Nobuharu
• Primary Examiner(s): Gutierrez, Diego
• Assistant Examiner(s): PRUCHNIC, STANLEY J
• Application Number:
  US09/367,164
• Publication Number:
  US 20020050068A1
• Time in Patent Office: 1,209 Days
• Field of Search: 333/91, 333/55.R, 333/56, 333/57, 333/58, 333/59, 333/61, 333/62, 333/661.1, 333/662.4, 334/02, 333/662.5, 333/662.6, 33D/IG.1, 200/61.45 R, 200/61.45 M, 200/61.52
• US Class Current: 33/391
• CPC Class Codes: G01C 2009/064 inductive
• CPC Class Codes: G01C 9/12 by using a single pendulum plumb lines G01C15/10

Abstract

An inclination sensor having excellent rotational performance, longlasting stability and high sensing precision. The inclination sensor comprises a pendulum (10) rotatably attached to a case (1) of a fixed body secured to an attached member, a magnetic flux-generating means (11) attached to the pendulum (10), reed switches (4a) and (4b) attached to part of the case (1) corresponding to the locus along which the magnetic flux-generating means (11) moves, and a flange portion (12) which is a damping body being nonmagnetic and electrically conductive and disposed in the case (1) along the locus of the movement of the magnetic flux-generating means (11).

Claims

1. An inclination sensor comprising:

a fixing body adapted to be attached to a mounting body;

a frame provided within said fixing body, said frame having a threaded bearing retention hole;

a bearing having a thread on a periphery thereof and fitted within said threaded bearing retention hole;

a pendulum having a rotary shaft rotatably supported in said bearing;

a magnetic flux generator mounted on said pendulum for rotatable movement with said pendulum through a rotational path; and

a reed switch mounted on said fixing body in the rotational path of said magnetic flux generator, said reed switch having a space of a distance d in a direction along an axis of said rotary shaft provided between said reed switch and said magnetic flux generator, wherein said space of a distance d is adjustable via said thread; and

at least one magnetic damping adjusting device made of a magnetic material and adjustably positioned on said fixing body.

2. The inclination sensor according to claim 1, further comprising a nonmagnetic and electrically conductive damping body positioned on said fixing body along the rotational path of said magnetic flux generator.

3. The inclination sensor according to claim 2, wherein said damping body is made of one of copper and aluminum.

4. The inclination sensor according to claim 2, wherein said damping body extends parallel to the axis of said rotary shaft.

5. The inclination sensor according to claim 2, wherein said damping body extends at an angle to the axis of said rotary shaft.

6. The inclination sensor according to claim 2, wherein said damping body has a circular arc shape.

7. The inclination sensor according to claim 2, wherein said damping body has a cylindrical shape.

8. The inclination sensor according to claim 2, wherein said damping body is composed of a first part which extends in one of a direction parallel with the axis of said rotary shaft and a direction at a predetermined angle with the axis of said rotary shaft, and a second part in the shape of a flat plate perpendicular to the axis of said rotary shaft.

9. The inclination sensor according to claim 8, further including a mechanism by which said damping body is mounted on said fixing body and the position of said reed switch is adjustable along the axis of said rotary shaft.

10. The inclination sensor according to claim 2, wherein said damping body is a flat plate and is located in the vicinity of one end of said magnetic flux generator and extends in the direction of a polar axis of said magnetic flux generator and perpendicular to said rotary shaft.

11. The inclination sensor according to claim 10, further including a mechanism by which said damping body is mounted on said fixing body and the position of said reed switch is adjustable along the axis of said rotary shaft.

12. The inclination sensor according to claim 1, wherein said rotary shaft has a reduced diameter at both ends.

13. The inclination sensor according to claim 1, further including a pin at each end of said rotary shaft.

14. The inclination sensor according to claim 13, wherein said pins are 0.3-1.5 [0.6] mm in diameter.

15. The inclination sensor according to claim 1, further including a second reed switch.

16. The inclination sensor according to claim 1, further including a second magnetic flux generator.

17. The inclination sensor according to claim 1, wherein said magnetic flux generator includes a magnet.

18. The inclination sensor according to claim 17, wherein said magnet is made of a samarium-cobalt system.

19. The inclination sensor according to claim 17, wherein said magnet is heat-treated at a temperature greater than a serviceable temperature thereof.

20. The inclination sensor according to claim 1, wherein said reed switch has a leaf and a major plane surface of said leaf is substantially parallel with the axis of said rotary shaft.

21. The inclination sensor according to claim 1, further including an electric resistance connected in parallel with said reed switch.

22. The inclination sensor according to claim 1, wherein said frame is made of a material having a high electrical conductivity, and positioned in a manner to confront said magnetic flux generator.

23. The inclination sensor according to claim 22, wherein said frame is made of one of copper, aluminum and brass.

24. The inclination sensor according to claim 1, further including a magneto-detecting element in the vicinity of said reed switch.

25. The inclination sensor according to claim 1, further including at least one reflection type interrupter on said fixing body facing a surface of said pendulum.

26. The inclination sensor according to claim 1, wherein said magnetic damping adjusting device is threaded and generally parallel with the axis of said rotary shaft.

27. The inclination sensor according to claim 1, wherein said reed switch has a leaf and said inclination sensor further includes a mechanism by which said leaf is mounted on said fixing body and which is rotatably adjustable about said rotary shaft.

28. The inclination sensor according to claim 1, further including a mechanism by which said reed switch is mounted on said fixing body along the axis of said rotary shaft.

29. The inclination sensor according to claim 1, wherein said magnetic flux generator and said reed switch are mounted with a polar axis of said magnetic flux generator parallel with the axis of said rotary shaft, and a central, longitudinal axis of said reed switch parallel with the axis of said rotary shaft.

30. The inclination sensor according to claim 29, further including additional magnetic flux generators.

31. The inclination sensor according to claim 29, further including a second magnetic flux generator and the polar orientations of said magnetic flux generators extend parallel with the axis of said rotary shaft in opposite directions to each other.

32. The inclination sensor according to claim 31, further including a magnetic yoke by which said magnetic flux generators are coupled together.

33. The inclination sensor according to claim 29, wherein said reed switch has a leaf and a major plane surface of said leaf is one of substantially parallel with the rotational radius of said pendulum and substantially perpendicular to the rotational radius of said pendulum.

34. The inclination sensor according to claim 29, wherein said reed switch has a leaf and said inclination sensor further includes a mechanism by which a contact point of said leaf is rotatably adjustable about said rotary shaft.

35. The inclination sensor according to claim 29, further including a mechanism for adjusting said reed switch along the axis of said rotary shaft.

36. The inclination sensor according to claim 29 further having a damping body composed of a first part which extends in one of a direction parallel with the axis of said rotary shaft and a direction at a predetermined angle with the axis of said rotary shaft, and a second part in the shape of a flat plate perpendicular to the axis of said rotary shaft.

37. The inclination sensor according to claim 29 further having a damping body of a flat plate located in the vicinity of one end of said magnetic flux generator and extending in the direction of the polar axis of said magnetic flux generator and perpendicular to said rotary shaft.

38. The inclination sensor according to claim 29, further including a mechanism for adjusting said reed switch along the rotational radius of said pendulum.

39. An inclination sensor comprising:

a fixing body adapted to be attached to a mounting body;

a pendulum mounted rotatably relative to said fixing body;

a magnetic flux generator mounted on said pendulum for rotatable movement with said pendulum through a rotational path;

a reed switch mounted on said fixing body in the rotational path of said magnetic flux generator; and

a nonmagnetic and electrically conductive damping body positioned on said fixing body along the rotational path of said magnetic flux generator, wherein said damping body has a shape of a circular arc cylinder or a semicircular cylinder wherein a cross sectional shape of said damping body is one of a reversed letter T, a letter J or a letter W.

40. An inclination sensor comprising:

a fixing body adapted to be attached to a mounting body;

a frame provided within said fixing body, said frame having a threaded bearing retention hole;

a bearing having a thread on a periphery thereof and fitted within said threaded bearing retention hole;

a pendulum having a rotary shaft rotatably supported in said bearing;

a magnetic flux generator mounted on said pendulum for rotatable movement with said pendulum through a rotational path; and

a plurality of reed switches mounted on said fixing body in respectively different locations about the rotational path of said magnetic flux generator to distinguish one of (a) between clockwise and counterclockwise rotation and (b) a plurality of rotating angles of said inclination sensor.