Latch sensing seat belt buckle

• US 6,357,091 B1
• Filed: 11/30/1999
• Issued: 03/19/2002
• Est. Priority Date: 11/30/1999
• Status: Expired due to Term

• Current Assignee: TRW Vehicle Safety Systems Incorporated (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: TRW Vehicle Safety Systems Incorporated (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Devereaux, Scott D.
• Primary Examiner(s): Sakran, Victor N.
• Application Number:
  US09/451,331
• Time in Patent Office: 840 Days
• Field of Search: 246/33, 246/45, 243/03, 246/03
• US Class Current: 24/633
• CPC Class Codes: B60R 2022/4816 for sensing locking of buckle
• CPC Class Codes: B60R 21/01546 using belt buckle sensors
• CPC Class Codes: B60R 22/48 Control systems, alarms, or interlock systems, for the correct application of the belt or harness
• CPC Class Codes: Y10T 24/32 having magnetic fastener
• CPC Class Codes: Y10T 24/45466 having electric or fluid powered, actuation or release, of interlock
• CPC Class Codes: Y10T 24/45623 and operator therefor
• CPC Class Codes: Y10T 24/45686 and position locking-means therefor

Abstract

An apparatus includes a lockable element (16) and a buckle (12). The buckle (12) includes a base (28) that defines a passage (32) into which the lockable element (16) is insertable, and a latch (42) movable to lock the lockable element against movement in the passage. The buckle (12) also includes a sensor (60) and a magnet (62). The magnet (62) is movable from a first position to a second position when the lockable element (16) is inserted into the passage (32). The magnet (62) creates a magnetic field of a first flux density acting on the sensor (60) to cause the sensor to provide a first output when the magnet is in the first position. The magnet (62) creates a magnetic field of a second flux density, different than the first flux density, acting on the sensor (60) to cause the sensor to provide a second output, different than the first output, when the magnet is in the second position. The magnet (62) has an interference fit with one of the lockable element (16) and the buckle (12).

Claims

1. Apparatus comprising:

a lockable element and a buckle for receiving and locking said lockable element in said buckle, said buckle comprising;

a base defining a passage into which the lockable element is insertable in a first direction;

a latch moveable to lock said lockable element against movement in said passage;

a sensor for sensing a magnetic field, said sensor providing an output signal, the magnitude of which is dependent upon the flux density of a magnetic field acting on said sensor; and

a magnet that is movable from a first position to a second position when said lockable element is inserted into said passage, said magnet creating a magnetic field of a first flux density acting on said sensor to cause said sensor to provide a first output signal when said magnet is in said first position;

said magnet creating a magnetic field of a second flux density that acts on said sensor, different than said first flux density, when said magnet is in said second position to cause said sensor to provide a second output signal different than said first output signal;

said magnet having an interference fit with one of said lockable element and said buckle, said one of said lockable element and said buckle including a first surface defining a shaped recess with a first length, said magnet having a second surface with a second length larger than said first length, said first and second surfaces being in abutting engagement and providing said interference fit.

2. Apparatus as defined in claim 1 wherein said sensor comprises a Hall effect device.

3. Apparatus as defined in claim 1 wherein said first flux density is zero.

4. Apparatus as defined in claim 1 wherein said second flux density is greater than said first flux density.

5. Apparatus comprising:

a lockable element and a buckle for receiving and locking said lockable element in said buckle, said buckle comprising;

a base defining a passage into which the lockable element is insertable in a first direction;

a latch moveable to lock said lockable element against movement in said passage;

a sensor for sensing a magnetic field, said sensor providing an output signal, the magnitude of which is dependent upon the flux density of a magnetic field acting on said sensor; and

a magnet that is movable from a first position to a second position when said lockable element is inserted into said passage, said magnet creating a magnetic field of a first flux density acting on said sensor to cause said sensor to provide a first output signal when said magnet is in said first position;

said magnet creating a magnetic field of a second flux density that acts on said sensor, different than said first flux density, when said magnet is in said second position to cause said sensor to provide a second output signal different than said first output signal;

said magnet having an interference fit with one of said lockable element and said buckle, said one of said lockable element and said buckle including a first cylindrical surface defining a cylindrically shaped recess having a first diameter, and said magnet having a second cylindrical surface of a second diameter, greater than said first diameter, said first and second cylindrical surfaces being in abutting engagement and providing said interference fit.

6. Apparatus as defined in claim 5 wherein said magnet has a substantially uniform cylindrical shape, said second cylindrical surface being generally smooth and without projections.

7. Apparatus as defined in claim 5 wherein said magnet is press fitted into said cylindrically shaped recess.

8. Apparatus comprising:

a lockable element and a buckle for receiving and locking said lockable element in said buckle, said buckle comprising;

a base defining a passage into which the lockable element is insertable in a first direction;

a latch moveable to lock said lockable element against movement in said passage;

a sensor for sensing a magnetic field, said sensor providing an output signal, the magnitude of which is dependent upon the flux density of a magnetic field acting on said sensor;

an ejector movable within said passage; and

a magnet that is movable from a first position to a second position when said lockable element is inserted into said passage, said magnet creating a magnetic field of a first flux density acting on said sensor to cause said sensor to provide a first output signal when said magnet is in said first position;

said magnet creating a magnetic field of a second flux density that acts on said sensor, different than said first flux density, when said magnet is in said second position to cause said sensor to provide a second output signal different than said first output signal;

said magnet having an interference fit with one of said lockable element and said buckle,

said ejector having a pair of guide portions engageable with said base and a central portion located between said guide portions, said central portion having a first cylindrical surface defining a cylindrically shaped recess having a first diameter, and said magnet having a second cylindrical surface of a second diameter, greater than said first diameter, said first and second cylindrical surfaces being in abutting engagement and providing said interference fit.

9. Apparatus as defined in claim 8 wherein said magnet is a permanent magnet made of metal and said ejector is made of plastic.

10. Apparatus as defined in claim 8 wherein said magnet has a flat end surface positioned flush with said central portion of said ejector.

11. Apparatus as defined in claim 8 wherein said magnet has a substantially uniform cylindrical shape, said second cylindrical surface being generally smooth and without projections.

12. Apparatus as defined in claim 8 wherein said magnet is press fitted into said cylindrically shaped recess.