Impact sensor

• US 5,670,764 A
• Filed: 12/20/1994
• Issued: 09/23/1997
• Est. Priority Date: 09/09/1991
• Status: Expired due to Fees

• Current Assignee: Aisin Seiki Co., Ltd. (Aisin Corp.)
• Original Assignee: Aisin Seiki Co., Ltd. (Aisin Corp.)
• Inventors: Ito, Koji, Onoda, Atsushi, Sakamoto, Kazunori, Ishikawa, Masanobu
• Primary Examiner(s): Gellner, Michael L.
• Assistant Examiner(s): Friedhofer, Michael A.
• Application Number:
  US08/360,116
• Time in Patent Office: 1,008 Days
• Field of Search: 74/2, 280/734, 200/61.45 R-61.45 M
• US Class Current: 200/61.45R
• CPC Class Codes: B60R 21/017 including arrangements for providing electric power to safety arrangements or their actuating means, e.g. to pyrotechnic fuses or electro-mechanic valves
• CPC Class Codes: B60R 21/33 Arrangements for non-electric triggering of inflation electrical circuits for triggering safety arrangements B60R21/01
• CPC Class Codes: G01P 15/135 by making use of contacts which are actuated by a movable inertial mass
• CPC Class Codes: H01H 35/14 Switches operated by change of acceleration, e.g. by shock or vibration, inertia switch wherein the liquid constitutes a contact of the switch H01H29/002

Abstract

A impact sensor includes a housing, a weight disposed within the housing for being moved by an externally applied impact that is in excess of a predetermined value, an output lever disposed within the housing for being disengaged by movement of the weight to move in one direction, a first contact point provided on the output lever, or the housing and a second contact point provided on the housing so as to lie on the path of movement of the output lever. The first and second contact points are electrically connected by coming into contact by movement of the output lever, thereby actuating an air-bag mechanism connected to the first and second contact points.

Claims

1. An impact sensor comprising:

a housing having an inner space and a wall for receiving an impact applied in a first direction;

a unitary assembly constructed independent of the housing and positioned within the housing for being secured to the housing, said unitary assembly including a frame having a first portion which extends along the wall of the housing and a second portion which extends transverse to the first portion;

a weight pivotally mounted on the second portion of the frame to rotate about a pivot axis when an impact is applied to the housing;

a cam provided on the weight;

an electrically conductive output lever pivotally mounted on the first portion of the frame for moving rotatably between one position in which a portion of the output lever engages the cam and another position in which a portion of the output lever extends outside the housing through the first portion of the frame in opposition to the first direction, the output lever having a first contact portion;

a spring urging the output lever against the cam; and

a contact plate mounted to the housing, a portion of the contact plate being spaced from the output lever to form a second contact portion for contact by said first contact portion, said second contact portion being located to be positioned on a path of movement of the first contact portion of said output lever, both the second contact portion and the output lever being continually connected to respective terminals of an electric current source;

said first and second portions being electrically connected via said output lever by coming into contact with a projection of the output lever, to close an electrical circuit to actuate an impact safety system electrically connected to said first and second contact portions, the spring maintaining electrical contact between the first and second contact portions upon movement of the weight by an external impact.

2. The impact sensor according to claim 1, wherein said spring is stretched between said housing and said output lever.

3. The impact sensor according to claim 1, further comprising moving means disposed between said housing and said weight to produce rotational sliding movement of said weight upon external impact.

4. The impact sensor according to claim 1, wherein said weight is supported by a shaft serving as a fulcrum offset from a center of gravity of said weight to produce a swinging motion of the weight upon the externally applied impact.

5. The impact sensor according to claim 4, wherein said housing includes a frame support within the housing;

said shaft being supported by the frame.

6. The impact sensor of claim 1 wherein the portion of the contact plate spaced from the housing is deformable upon movement of the output lever to its operated position.

7. An impact sensor comprising:

a housing having an inner space and a wall for receiving an impact applied in a first direction;

a unitary assembly constructed independent of the housing and positioned within the housing for being secured to the housing, said unitary assembly including a frame having a first portion which extends along the wall of the housing and a second portion which extends transverse to the first portion;

a weight pivotally mounted on the second portion of the frame to rotate about a pivot axis when an impact is applied to the housing;

a cam provided on the weight;

an electrically conductive output lever pivotally mounted on the first portion of the frame for moving rotatably between one position in which a portion of the output lever engages the cam and another position in which a portion of the output lever extends outside the housing through the first portion of the frame in opposition to the first direction;

a spring urging the output lever against the cam;

a first contact point and a second contact point provided on said housing positioned in spaced relation along the path of movement between the engaged position and the operated position of the said output lever, said first contact point and the second contact point being continually connected to a respective terminal of an electric current source;

said first and second contact points being electrically connected via the output lever by coming into contact with said output lever during movement of said output lever to the operated position, to actuate a first impact safety system connected to said first and second contact points; and

an output pin mounted to the output lever to activate a second impact safety system substantially simultaneously with the first impact safety system in response to the movement of the output lever to the operated position.

8. The impact sensor according to claim 7, wherein movement of said weight is a swinging motion about a fulcrum obtained by supporting said weight on the frame at a position offset from a center of gravity of said weight.

9. The impact sensor of claim 7 wherein, the first contact point is a projection that extends substantially perpendicular from the output lever intermediate the ends thereof.

10. The impact sensor of claim 7 wherein the first and second contact points are flexible members slidably engaged by the output lever.

11. The impact sensor of claim 7 wherein the first and second contact points are provided on a portion of the housing perpendicular to a plane of movement of the output lever, and the pair of spaced contact portions of the output lever are formed on a side surface thereof along the plane of movement of the output lever.

12. An impact sensor comprising:

a housing having an inner space and a wall for receiving an impact applied in a first direction;

a unitary assembly constructed independent of the housing and positioned within the housing for being secured to the housing, said unitary assembly including a frame having a first portion which extends along the wall of the housing and a second portion which extends transverse to the first portion;

a weight pivotally mounted on the second portion of the frame to rotate about a pivot axis when an impact is applied to the housing;

a cam provided on the weight;

an electrically conductive output lever pivotally mounted on the first portion of the frame for moving rotatably through an angle less than ninety degrees between one position in which a portion of the output lever engages the cam and another position in which another portion of the output lever extends outside the housing through the first portion of the frame in opposition to the first direction;

a spring urging the output lever against the cam;

a first contact surface and a second contact surface located on said housing in spaced relation to be electrically engaged by a respective one of a pair of spaced contact portions of the output lever during movement of said output lever to the operated position in response to an external impact, both the first and second contact surfaces being continually connected to a respective terminal of an electric current source;

said first and second contact surfaces and said pair of spaced contact portions being electrically connected via said output lever by sliding contact with said pair of spaced contact portions of the lever to close an electrical circuit actuating a first impact safety system connected, to said first and second contact surfaces, and to simultaneously actuate a second impact safety system in response to the striking of a detonator by a projection on the lever, the spring maintaining constant electrical contact between the pair of spaced contact portions and the first and second contact surfaces with the output lever in an operated position.

13. The impact sensor of claim 12 wherein the output lever has two projections extending in different direction, said projections each having one of the pair of contact portions.

14. The impact sensor of claim 13 wherein the pointed projection extends from one of the two projections in a direction different from said one projection.

15. The impact sensor of claim 12 wherein the first and second contact surfaces are provided on a portion of the housing perpendicular to a plane of movement of the output lever, and the pair of spaced contact portions of the output lever are formed on a side surface thereof along the plane of movement of the output lever.