Locking sensor for belt retractor

• US 4,103,842 A
• Filed: 07/07/1975
• Issued: 08/01/1978
• Est. Priority Date: 07/07/1975
• Status: Expired due to Term

• Current Assignee: REPA Feinstanzwerk GmbH
• Original Assignee: REPA Feinstanzwerk GmbH
• Inventors: Scibbe, Harold R., Martin, Thomas F., Nagy, James A.
• Primary Examiner(s): Hornsby, Harvey C.
• Assistant Examiner(s): Jillions, John M.
• Application Number:
  US05/593,276
• Time in Patent Office: 1,121 Days
• Field of Search: 242/107.4 R, 242/107.4 A, 242/107.2, 180/82 C, 280/744-747, 340/52 E, 307/103 B, 188/135, 188/137-139, 200/61.45 M, 200/61.45 R, 200/61.48, 200/61.49, 200/61.52, 200/61.58 B, 310/DIG. 3, 317/124, 297/386-388
• US Class Current: 242/384
• CPC Class Codes: B60R 22/343 with electrically actuated locking means B60R22/3405 takes precedence
• CPC Class Codes: G01P 15/093 by photoelectric pick-up
• CPC Class Codes: H01H 35/147 the switch being of the reed switch type

Abstract

An emergency locking retractor system for storing a length of safety belt incorporates a sensor which includes a multi-directional pendulum device displaceable from its rest position by acceleration. Displacement of the pendulum is utilized to change the strength of an energy field imposed upon an electrical signal means. The output signal of the signal means responds to the change in the energy field imposed thereon and the changed signal is employed to activate solenoid switches which lock the retractor. The energy field source may be a magnet or a light source and the signal means then may include, respectively, a Hall device or a phototransistor. Movement of the pendulum from its rest position is utilized to move the magnet closer to or further from the Hall device, or to interpose a shield between the light source and the phototransistor, or to change the position of a reflector used to reflect light from the light source onto the phototransistor. The resultant change in output signal is employed to close a circuit which connects a power source to the locking medium.

Claims

1. An emergency locking belt retractor device for a vehicle, said device comprising a belt retractor and a retractor lock associated therewith, lock control means actuable to cause the retractor to lock the belt retractor, an electrical circuit including (1) signal means incorporating a Hall device and including means for generating an output signal which changes in magnitude in response to changes in a magnetic field imposed on the Hall device, (2) circuit means for actuating the lock control means to engage the lock with a retractor to lock the retractor, and (3) circuit closing means for causing said output signal of said signal means to close said circuit means to lock said retractor at a predetermined magnitude of said output signal, an inertia member mounted for displacement from a rest position in response to gravitational inertial forces due to predetermined modes of movement of the vehicle including a pendulum weight, a magnet connected with said inertia member and mounted on the bottom of said pendulum weight, and being disposed in a predetermined position with respect to said signal means for imposing its field on said Hall device when said inertia member is in said rest position, means including said inertia member for displacing the magnet relative to said Hall device in response to displacement of said inertia member from said rest position for varying the strength of the magnetic field imposed on the signal means in response to movement of said inertia member from the rest position for varying the magnitude of said output signal.

2. The device of claim 1 wherein said signal means is mounted at a location which is adjacent to said magnet when said pendulum is in its rest position.

3. An emergency locking belt retractor device for a vehicle, said device comprising a belt retractor and a lock associated therewith, said lock including electrically operated lock control means and electrical signal means incorporating a Hall device to generate an output signal the strength of which is responsive to the strength of an energy field imposed on said signal means, said device further including an electrical circuit including a power supply and circuit closing means responsive to a predetermined magnitude of said output signal to close the circuit and actuate said lock control means, said electrically operated lock control means being connected to said power supply by said electrical circuit and said electrically operated lock control means also including a switching transistor connected in series with said power supply and said lock control means by its emitter and control terminals, a supply of power connected to the base terminal of said switching transistor and controlled by current flow through said Hall device, the conductivity of which is dependent upon the intensity of a magnetic field imposed thereon, an energy field source including a magnet for imposing said magnetic field on said signal means, energy field control means adapted to change the intensity of said magnetic field imposed on said Hall device in response to acceleration so as to increase the flow of current to said base terminal to close the circuit and thereby actuate said electrically operated lock control means, and including an inertia member, means for supporting said inertia member in a rest position under the influence of gravity and for permitting displacement of said inertia member from said rest position in response to a horizontal component of gravitational or inertial forces due to predetermined modes of movement of the vehicle in any direction, said energy field control means including said magnet connected with said inertia member and being movable in a predetermined manner in response to movement of said inertia member, said energy field control means including means for maintaining the strength of the energy field imposed on said signal means by said energy field source substantially constant and at a maximum value when said inertia member is in said rest position, said energy field control means further including means for decreasing the strength of the energy field imposed on said signal means in response to displacement of said inertia member from said rest position, electrically operated lock control means being responsive to a predetermined degree of change of the strength of the output signal to actuate said lock to effect locking of the belt retractor, said energy field source and said signal means being physically unconnected to each other, and the magnetic field existing between said energy field source and said signal means being insufficient to resist displacement of said inertia member from said rest position in response to change in the speed of said vehicle in any horizontal direction.

4. An emergency locking belt retractor device for a vehicle, said device comprising a belt retractor and a retractor lock associated therewith, lock control means actuable to cause the retractor lock to lock the belt retractor, an electrical circuit including (1) signal means incorporating a Hall device and including means for generating an output signal which changes in magnitude in response to changes in a magnetic field imposed on the Hall device, (2) circuit means for actuating the lock control means to engage the lock with the retractor to lock the retractor, and (3) circuit closing means for causing said output signal of said signal means to close said circuit means to lock said retractor at a predetermined magnitude of said output signal, inertia responsive means comprising a pendulum having a pendulum weight mounted for displacement from a rest position in response to gravitational inertial forces due to predetermined modes of movement of the vehicle, a magnet fixedly connected with said pendulum weight and being disposed in a predetermined position with respect to said signal means for imposing its field on said Hall device when said pendulum weight is in said rest position, means including said pendulum weight for displacing the magnet relative to said Hall device in response to displacement of said pendulum weight from said rest position for varying the strength of the magnetic field imposed on the signal means in response to movement of said pendulum weight from the rest position for varying the magnitude of said output signal.

5. The device of claim 4 wherein the circuit closing means includes amplifier means to amplify the output signal.

6. The device of claim 4 wherein pendulum weight is mounted on a rigid rod affixed to a pivot plate pivotably mounted within a pivot chamber.

7. The device of claim 4 wherein said energy field control means, said energy field source and said signal means are encapsulated in a protective container.

8. An emergency locking belt retractor device for a vehicle, said device comprising a belt retractor and a lock associated therewith, said lock including mechanically static signal means to generate an output signal the strength of which is responsive to the strength of an energy field imposed on said signal means, an energy field source for imposing an energy field on said mechanically static signal means, energy field control means for changing the strength of the energy field imposed on said signal means in response to predetermined modes of movement of the vehicle, said energy field control means comprising a pendulum including a pendulum weight, a rigid rod having a first portion fixed to said pendulum weight, a pivot plate having a peripheral rim portion, said rigid rod having a second portion connected with said pivot plate, pendulum support means comprising means defining a support surface disposed to engage a selected portion of said pivot plate to freely support said pendulum weight under the influence of gravity in a rest position with said rigid rod extending in first direction, said pendulum support means further defining housing means for allowing said pivot plate to pivot about relative to said support surface to allow displacement of said pendulum weight from said rest position in response to inertial or gravitational forces on said pendulum weight above a predetermined amount and means for preventing more than a predetermined degree of movement of said pivot plate in directions transverse to said first direction, said energy source being carried by said pendulum for changing the strength of the energy field imposed on said mechanically static signal means to vary the strength of said output signal in response to displacement of said pendulum from said rest position, and lock control means operative in response to a predetermined amount of change in the strength of said output signal to actuate said lock to effect locking of the belt retractor.

9. Apparatus as defined in claim 8 wherein said signal means comprises a Hall device, and wherein said means carried by said pendulum comprises a magnet fixedly connected with the bottom of the said pendulum weight.

10. In a vehicle having an occupant restraint system having means for restraining forward movement of an occupant in response to an emergency condition including a retractor connected with the restraint system, an emergency locking system including means for actuating the retractor to place the restraint system in a condition in which it restrains forward movement of the occupant, lock control means actuable to lock the retractor, an electrical circuit including mechanically static signal means including means for generating an electric output signal which changes in magnitude in response to changes in the magnitude of an energy field imposed on said mechanically static signal means, an energy field source for imposing an energy field on said mechanically static signal means, circuit means for causing said output signal of said signal means to actuate said lock control means to actuate said retractor at a predetermined magnitude of said output signal, and means for changing the magnitude of the energy field on said mechanically static signal means comprising a pendulum having a pendulum weight mounted for multidirectional displacement from a rest position in response to gravitational-inertial forces due to predetermined modes of the vehicle during an emergency condition, said energy field source being fixedly connected with said pendulum weight and being movable therewith in response to gravitational-inertial forces to change the strength of the energy field on said mechanically static signal means.

11. The device of claim 10 wherein said signal means comprises electrical signal means, said lock control means comprises an electrically operated lock control means, said circuit means including an electrical circuit including a power supply and a circuit closing means responsive to the predetermined magnitude of said output signal to close said circuit to actuate said lock control means.

12. The device of claim 11 further including amplifier means to amplify said output signal and wherein said circuit closing means comprises switch means responsive to the amplified output signal to close said circuit.

13. The device of claim 10 wherein said energy field source is a magnet, said energy field is a magnetic field, and said electrical signal means includes a Hall device.

14. The device of claim 10 wherein said pendulum weight is suspended on a calibrated wire.

15. The device of claim 10 wherein said said pendulum weight is mounted on a rigid rod affixed to a pivot plate pivotably mounted within a pivot chamber.

16. The device of claim 10 wherein said energy field control means, said energy field source and said signal means are encapsulated in a protective container.

17. Apparatus as defined in claim 10 wherein said pendulum includes means for damping movement of said pendulum from said rest position.

18. The device of claim 10 wherein said signal means includes a phototransistor, and wherein said energy field source comprises means fixedly connected with said pendulum weight for directing light energy relative to said phototransistor.

19. The device of claim 10 wherein said lock control means are connected to a power supply by said circuit means, said circuit means including a switching transistor connected in series with said power supply and said lock control means by its emittor and control terminals, a supply of power connected to the base terminal of said switching transistor and controlled by current flow through said phototransistor, the conductivity of which is dependent upon the intensity of light imposed thereon, said pendulum weight being effective to move the field source relative to the phototransistor to change the intensity of light imposed on said phototransistor in response to gravitational-inertial forces so as to increase the flow of current to said base terminal to close the circuit and thereby actuate said lock control means.

20. The device of claim 19 wherein said energy field source comprises a reflective surface mounted on said pendulum weight which, when said pendulum weight is in its rest position reflects a predetermined amount of light onto said phototransitor, said pendulum being effective to displace said reflective surface from its rest position in response to said predetermined modes of movement of the vehicle to diminish the intensity of light reflected onto said phototransistor.

21. The device of claim 20 wherein said reflective surface comprises a convex reflective surface.

22. An emergency locking belt retractor device for a vehicle, said device comprising a belt retractor and a lock associated therewith, said lock including mechanically static signal means to generate an output signal the strength of which is responsive to the strength of an energy field imposed on said signal means, an energy field source for imposing an energy field on said mechanically static signal means, energy field control means for changing the strength of the energy field imposed on said signal means in response to predetermined modes of movement of the vehicle, said energy field control means comprising a pendulum including a pendulum weight, a rigid rod having a first portion fixed to said pendulum weight, a pivot plate extending transverse to said rigid rod, said rigid rod having a portion fixedly connected with said pivot plate, pendulum support means comprising means defining a support surface disposed to engage selected portions of said pivot plate spaced from the point of attachment of said pivot plate with said rigid rod to freely support said pendulum weight under the influence of gravity in a rest position with said rigid rod extending in first direction and allowing said pivot plate to pivot about said selected portions to allow multi-directional displacement of said pendulum weight from said rest position in response to inertial or gravitational forces on said pendulum weight above a predetermined amount, said energy field source being carried by said pendulum for changing the strength of the energy field imposed on said mechanically static signal means to vary the strength of said output signal in response to multi-directional displacement of said pendulum from said rest position, and lock control means operative in response to a predetermined amount of change in the strength of said output signal to actuate said lock to effect locking of the belt retractor.

23. Apparatus as defined in claim 22 wherein said signal means comprises a Hall device, and wherein said energy field source comprises a magnet fixedly connected with the bottom of the said pendulum weight.

24. Apparatus as defined in claim 22 including housing means for preventing more than a predetermined degree of movement of said pivot plate in directions transverse to said first direction.