METHOD FOR DOWNSIZING A SAFETY DEVICE FOR A MOTOR VEHICLE

• US 20130092778A1
• Filed: 04/04/2011
• Published: 04/18/2013
• Est. Priority Date: 04/09/2010
• Status: Active Grant

• Current Assignee: Volkswagen AG
• Original Assignee: Volkswagen AG
• Inventors: Dramlitsch, Thomas
• Granted Patent: US 8,794,672 B2
• Time in Patent Office: Days
• US Class Current: 242/382
• CPC Class Codes: B60R 2022/288 with means to adjust or regulate the amount of energy to be absorbed
• CPC Class Codes: B60R 22/36 self-locking in an emergency B60R22/3405 , B60R22/343 take precedence
• CPC Class Codes: B60R 22/41 with additional means for preventing locking during unwinding under predetermined conditions

Abstract

A method of downscaling the travel-time-function of a reference body of mass m_t in a spring-mass system with a spring providing a spring force when the spring-mass system is exposed to an acceleration field with an acceleration which moves the reference body against the spring force according to the travel-time-function is provided. In this method, the downscaling is done by coupling the reference body of mass m_t to additional masses m_r which are kinematically linked together in such a way that they do not react to acceleration field.

Claims

1. Method of downscaling the travel-time-function of a reference body of mass m_t in a spring-mass system with a spring providing a spring force when the spring-mass system is exposed to an acceleration field with an acceleration which moves the reference body against the spring force yielding the travel-time-function, characterized in that the downscaling is done by coupling the reference body of mass m_t to additional masses m_r which are kinematically linked together in such a way that they do not react to the acceleration field.

2. Method according to claim 1, characterized in that the additional masses m_r are rotating masses having rotational inertias.

3. Method according to claim 2, characterized in that the mass m_t of the reference body is smaller than the additional masses m_r.

4. Method according to claim 1, characterized in that gearwheels or flywheels are used to provide the additional masses m_r.

5. Method according to claim 4, characterized in that the radius at which the reference body acts on the flywheel is smaller than the radius of the flywheel.

6. Method according to claim 4, characterized in that a transmission is used between the reference body and the flywheel or gearwheel.

7. Method according to claim 6, characterized in that the transmission has a transmission ratio of >

2.

8. Method of establishing belt pull-out with a specified travel-time-function in a vehicle occupant restraint system during an accident exposing the vehicle to an acceleration field, in which the occupant restraint system comprises a seat belt, a spring-mass system with a reference body of mass m_t which is exposed to the acceleration field and which can be moved against the spring force by an acceleration of the acceleration field, and a blocking and releasing device for blocking and releasing belt pull-out of the seat belt, wherein the travel-time-function of the reference body when moving against the spring force mechanically establishes the travel-time-function of the belt pull-out via the blocking and releasing device of the occupant restraint system, characterized in that, when establishing the belt pull-out with the specified travel-time-function, the travel-time-function of the reference body is scaled down according to claim 1.

9. Method according to claim 8, characterized in that a transmission is used between the motion of the reference body and the actual belt pull-out.

10. Method according to claim 9, characterized in that a transmission increases the travel-time-function of the belt pull-out resulting from the travel-time-function of the reference mass at least by a factor of (m_t+m_r)/m_t.

11. Spring-mass device comprising a spring with a defined spring force and a reference body of mass m_t movable against the spring force in an acceleration field, characterized by additional masses m_r which are kinematically linked together in such a way that they do not react to acceleration field and which are coupled to the reference body of mass m_t.

12. Spring-mass device according to claim 11, characterized in that the additional masses m_r are rotating masses having rotational inertias.

13. Spring-mass device according to claim 12, characterized in that the mass m_t of the reference body is smaller than the additional masses m_r.

14. Spring-mass device according to claim 11, characterized in that the additional masses m_r. are provided in form of gearwheels or flywheels.

15. Spring-mass device according to claim 14, characterized in that the flywheels are coupled to the reference mass by a band, a belt or a chain wrapped around the flywheels and connected to the reference mass.

16. Spring-mass device according to claim 15, characterized in that the band, belt or chain is connected to opposite sides the reference mass.

17. Spring-mass device according to claim 14, characterized in that the radius at which the reference body is coupled to the flywheels is smaller than the radius of the flywheels.

18. Spring-mass device according to claim 14, characterized in a transmission between the reference body and the flywheels or gearwheels.

19. Spring-mass device according to claim 18, characterized in that the transmission has a transmission ratio of >

2.

20. Vehicle occupant restraint system comprising

a seat belt which provides, in an accident, a belt pull-out according to a specified travel-time-function of the belt pull-out;

a spring-mass device with a spring providing a defined spring force and a reference body of mass m_t;

which can move against the spring force in acceleration filed yielding a travel-time-function of the reference body; and

a blocking and releasing device for blocking and releasing belt pull-out of the seat belt,

wherein

the spring-mass system is linked to the blocking and releasing device so as to mechanically establish the travel-time-function of the belt pull-out via the blocking and releasing device of the occupant restraint system according to the travel-time-function of the reference body,

characterized in that

the spring-mass device is designed according to claim 11.

21. Vehicle occupant restraint system according to claim 20, characterized by a transmission between the spring-mass device and the actual belt pull-out.

22. Vehicle occupant restraint system according to claim 21, characterized in that that the transmission increases the travel-time-function of the belt pull-out resulting from the travel-time-function of the reference mass at least by a factor of (m_t+m_r)/m_t.