Acceleration sensor

• US 6,470,746 B1
• Filed: 11/29/2000
• Issued: 10/29/2002
• Est. Priority Date: 07/28/1998
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Tokai RIKA Denki Seisakusho
• Original Assignee: Kabushiki Kaisha Tokai RIKA Denki Seisakusho
• Inventors: Yamashita, Tatsuo, Umezawa, Yoshio, Murayama, Yasunori, Hori, Seiji, Nagata, Tomonori, Kato, Keiichi, Imai, Keisuke
• Primary Examiner(s): MOLLER, RICHARD ALAN
• Application Number:
  US09/701,677
• Time in Patent Office: 699 Days
• Field of Search: 734/93, 734/88, 280/801.1, 297/474, 297/475, 297/476, 297/478, 297/479, 297/480, 297/468, 297/469
• US Class Current: 73/493
• CPC Class Codes: B60R 2022/403 using externally controlled means, e.g. linked with seat back hinge
• CPC Class Codes: B60R 22/40 responsive only to vehicle movement
• CPC Class Codes: G01P 1/023 for acceleration measuring devices
• CPC Class Codes: G01P 15/036 for indicating predetermined acceleration values
• CPC Class Codes: G01P 15/135 by making use of contacts which are actuated by a movable inertial mass

Abstract

An object of the present invention is to obtain an acceleration sensor that can reliably detect acceleration when inclination of an inclining member is within a fixed range, and that can reduce unnecessary movement of relevant members when inclination of the inclining member is outside of the range, so that space efficiency in an inner portion is high. In the present invention, a gear of a fixed gear fixed at a seat cushion is formed in only a portion in the circumferential direction, and a portion at which the gear is not formed is a sliding surface. One of teeth among a plurality of teeth of a pinion of a revolving gear is short, to form a notched tooth portion. In a state in which the forward-collapsed angle of a seatback exceeds a predetermined angle, the notched tooth portion faces the sliding surface and the revolving gear body no longer rotates. At this time, since a bracket at which a sensor ball is mounted also does not rotate, the bracket is held at a fixed position relative to a frame plate. Accordingly, a space formed in frame plates in consideration of rotation of the bracket does not need to be large, and space efficiency is high.

Claims

1. An acceleration sensor, comprising:

a supporting body attached to an inclinable inclining member so as to be rotatable at least about an axis parallel with an inclination center of the inclining member;

a moving body supported at the supporting body, for driving an output member by being inertially moved by an acceleration of a predetermined value or more;

angle maintaining means for interlocking with inclination of the inclining member to maintain the supporting body at a fixed angle with respect to the horizontal plane; and

interlock prevention means for, when the inclining member inclines exceeding a predetermined angle of inclination, preventing interlock of the angle maintaining means with respect to the inclining member and fixedly maintaining a relative position of the angle maintaining means with respect to the inclining member.

2. The acceleration sensor according to claim 1, wherein the acceleration is detected due to the moving body being inertially moved by the acceleration of the predetermined value or more to drive the output member.

3. The acceleration sensor according to claim 2, wherein

the angle maintaining means comprises:

a fixed gear body fixed coaxially with the inclination center of the inclining member; and

a revolving gear body attached to the inclining member so as to be able to revolve with respect to the fixed gear body to thereby mesh with the fixed gear body, and

the interlock prevention means comprises;

a releasing portion for releasing meshing of the fixed gear body and the revolving gear body when the inclining member inclines exceeding a predetermined angle of inclination; and

a fixing portion for, when the meshing of the fixed gear body and the revolving gear body is released, fixing the revolving gear body such that relative rotation thereof with respect to the inclining member is impossible.

4. The acceleration sensor according to claim 3, wherein the angle maintaining means includes a weight fixedly mounted to the supporting body.

5. The acceleration sensor according to claim 4, wherein the angle maintaining means includes means for interlocking to rotate the supporting body in the opposite direction to a rotational direction of the inclining member so as to make the rotational angle of the supporting body equal to a rotational angle of the inclining member.

6. The acceleration sensor according to claim 5, wherein the releasing portion of the interlock prevention means is a notched tooth portion provided at the revolving gear body.

7. The acceleration sensor according to claim 2, wherein

the angle maintaining means comprises:

a rotating body fixed at the supporting body so as to be rotatable about the rotational axis of the supporting body; and

rotating means for interlocking with inclination of the inclining member so as to be able to rotate the rotating body in the opposite direction to the inclination direction of the inclining member and at the same angle as the inclination of the inclining member, and

the interlock prevention means comprises;

means for abutting the supporting body when the inclining member inclines exceeding a predetermined angle, to prevent relative rotation of the supporting body with respect to the inclining member; and

allowing means for allowing the rotating means to rotate relatively to the rotating body, in a state in which the interlock prevention means has prevented relative rotation of the supporting body with respect to the inclining member.

8. The acceleration sensor according to claim 5, wherein the releasing portion of the interlock prevention means is a notched tooth portion provided at the fixed gear body.

9. The acceleration sensor according to claim 5, wherein the fixing portion of the interlock prevention means is a sliding surface provided at the fixed gear body.

10. The acceleration sensor according to claim 2, wherein

the angle maintaining means comprises

a fixed gear body fixed coaxially with the inclination center of the inclining member, and

a gear structure for rotating the supporting body, the gear structure being meshed with the fixed gear body and thereby rotating the supporting body about the rotational axis thereof when the fixed gear body is rotated, and

the interlock prevention means comprises

a releasing portion for releasing meshing of the fixed gear body and the gear structure when the inclining member inclines exceeding a predetermined angle of inclination, and

a fixing portion for, when the meshing of the fixed gear body and the gear structure is released, fixing the gear structure such that relative rotation thereof with respect to the inclining member is impossible.

11. The acceleration sensor according to claim 10, wherein the releasing portion of the interlock prevention means is a notched tooth portion provided at the gear structure.

12. The acceleration sensor according to claim 10, wherein the fixing portion of the interlock prevention means is a sliding surface provided at the fixed gear body.

13. The acceleration sensor according to claim 5, wherein the angle maintaining means further includes a face wheel which moves by interlocking with the revolving gear body and the face wheel includes a control protrusion having a pair of side walls, and when the inclining member inclines within a range of a predetermined angle of inclination, the control protrusion is constantly maintained at a predetermined angle with respect to the horizontal plane.

14. The acceleration sensor according to claim 13, wherein when the inclining member inclines within a range of a predetermined angle of inclination, a control shaft of the supporting body and a rotational shaft of the supporting body are reliably maintained on a single vertical line passing between the pair of side walls.

15. The acceleration sensor according to claim 13, wherein when a vehicle itself inclines in a pitching direction, the face wheel rotates about the rotational axis of the supporting body together with a vehicle body, and as a result, a control protrusion, the supporting body is pressed by one of the side walls of the control protrusion, the supporting body inclines with respect to the vehicle body, and the output member is driven.

16. The acceleration sensor according to claim 14, wherein a predetermined clearance is provided between each of the side walls of the control protrusion and the control shaft.

17. The acceleration sensor according to claim 16, wherein the clearance is formed such that the supporting body is able to rotate within a fixed range independently of the face wheel, by weight of the weight.

18. An acceleration sensor, comprising:

a supporting body attached to an inclinable inclining member so as to be rotatable at least about an axis parallel with an inclination center of the inclining member;

a moving body supported at the supporting body, for driving an output member by being inertially moved by an acceleration of a predetermined value or more;

angle maintaining means for interlocking with inclination of the inclining member to maintain the supporting body at a fixed angle with respect to the horizontal plane; and

interlock prevention means for, when the inclining member inclines exceeding a predetermined angle of inclination, preventing interlock of the angle maintaining means with respect to the inclining member and fixedly maintaining a relative position of the angle maintaining means with respect to the inclining member, wherein

the interlock prevention means comprises;

means for abutting the supporting body when the inclining member inclines exceeding a predetermined angle, to prevent relative rotation of the supporting body with respect to the inclining member; and

allowing means for allowing the rotating means to rotate relatively to the rotating body, in a state in which the interlock prevention means has prevented relative rotation of the supporting body with respect to the inclining member.

19. The acceleration sensor according to claim 18, wherein the acceleration is detected due to the moving body being inertially moved by the acceleration of the predetermined value or more to drive the output member.