Vehicle seatbelt assembly

1. A vehicle seatbelt assembly comprising:

a load limiter having a seatbelt attachment portion and a seatbelt tension control mechanism that is configured to increase the length of a shoulder portion of a seatbelt in response to rapid or sudden deceleration of a vehicle, thereby reducing a level of tension experience by a seatbelt, the seatbelt tension control mechanism further including a clutch mechanism disposed between the first member and the second member, the clutch mechanism being operable to switch between a dis-engaged state allowing movement of the second member relative to the first member and an engaged state preventing movement of the second member relative to the first member.

2. The vehicle seatbelt assembly according to claim 1 , wherein

the seatbelt tension control mechanism includes a first member configured to attach to one of a vehicle floor structure and a seat structure and a second member supported on the first member, the second member being configured for limited sliding movement relative to the first member.

3. The vehicle seatbelt assembly according to claim 2 , wherein

the seatbelt attachment portion is defined by a buckle mechanism attached to the second member for movement therewith, the buckle mechanism having a latch device configured to releasably retain a seatbelt latch tongue member of the seatbelt.

4. The vehicle seatbelt assembly according to claim 1 , wherein

the clutch mechanism includes a magnetorheological fluid that is electronically activated such that with an electric current being provided to the clutch mechanism, the clutch is in the engaged state, and in the absence of an electric current being provided to the clutch mechanism the clutch is in the dis-engaged state.

5. The vehicle seatbelt assembly according to claim 4 , wherein

the second member is spring biased to move toward a first orientation relative to the first member, and

the clutch mechanism is configured to retain the second member in the first orientation relative to the first member.

6. The vehicle seatbelt assembly according to claim 4 , further comprising:

an electronic controller connected to the clutch mechanism, the controller being configured to operate the clutch mechanism to change from the engaged state to the dis-engaged state in response to detection of a tensioning event.

7. The vehicle seatbelt assembly according to claim 6 , wherein

the tensioning event is one of the following: a rapid deceleration of the vehicle body structure, a hard-braking event and an impact event.

8. The vehicle seatbelt assembly according to claim 6 , wherein

the buckle mechanism is attached to the second member via a coupling member such that the buckle mechanism is a first distance away from the first member by a predetermined distance with the clutch mechanism in the engaged state, and

in response to the controller operating the clutch mechanism to change from the engaged state to the dis-engaged state movement of the second member relative to the first member changes the location of the buckle mechanism such that with the clutch mechanism in the dis-engaged state the buckle mechanism is a second distance away from the first member, the second distance being greater than a first distance.

9. A vehicle seatbelt assembly comprising:

a seat structure configured to install a floor structure of a passenger compartment of a vehicle;

a seatbelt having a first end fixed to one of the floor structure or the seat structure and a shoulder portion spaced apart from the first end;

a load limiter having a seatbelt attachment portion and a seatbelt tension control mechanism that are attached to the seat structure along one side of a seat cushion portion of the seat structure, the seatbelt attachment portion being connectable to the shoulder portion of the seatbelt, the seatbelt tension control mechanism being configured to increase the length of the shoulder portion of the seatbelt in response to rapid or sudden deceleration of a vehicle, thereby reducing a level of tension experience by a seatbelt.

10. The vehicle seatbelt assembly according to claim 9 , wherein

the load limiter further includes the following:

a first member attached to the one of floor structure or the seat structure;

a second member supported on the first member and being attachable to the shoulder portion of the seatbelt, the second member being configured for limited sliding movement relative to the first member; and

a clutch mechanism disposed between the first member and the second member, the clutch mechanism being operable to switch between a dis-engaged state allowing movement of the second member relative to the first member and an engaged state preventing movement of the second member relative to the first member.

11. The vehicle seatbelt assembly according to claim 10 , wherein

the seatbelt attachment portion includes a buckle mechanism attached to the second member for movement therewith; and

the shoulder portion of the seatbelt having a seatbelt latch tongue member that is configured to releasably attach to the buckle mechanism.

12. The vehicle seatbelt assembly according to claim 10 , wherein

the clutch mechanism includes a magnetorheological fluid that is electronically activated such that with an electric current being provided to the clutch mechanism, the clutch is in the engaged state, and in the absence of an electric current being provided to the clutch mechanism the clutch is in the dis-engaged state.

13. The vehicle seatbelt assembly according to claim 10 , wherein

the second member is spring biased to move toward an at rest position relative to the first member, and

the clutch mechanism is configured to retain the second member in the at rest position relative to the first member.

14. The vehicle seatbelt assembly according to claim 10 , further comprising:

an electronic controller connected to the clutch mechanism, the controller being configured to operate the clutch mechanism to change from the engaged state to the dis-engaged state in response to detection of a tensioning event.

15. The vehicle seatbelt assembly according to claim 14 , wherein

the tensioning event is one of the following: a rapid deceleration of the vehicle body structure, a hard-braking event and an impact event.

16. The vehicle seatbelt assembly according to claim 14 , wherein

the buckle mechanism is attached to the second member via a coupling member such that the buckle mechanism is a first distance away from the first member by a predetermined distance with the clutch mechanism in the engaged state, and

in response to the controller operating the clutch mechanism to change from the engaged state to the dis-engaged state movement of the second member relative to the first member changes the location of the buckle mechanism such that with the clutch mechanism in the dis-engaged state the buckle mechanism is a second distance away from the first member, the second distance being greater than a first distance.

17. The vehicle seatbelt assembly according to claim 14 , wherein

the first member includes a positioning mechanism configured to adjust an at rest position of the second member relative to the first member; and

the clutch mechanism is configured to retain the second member in the at rest position.

18. The vehicle seatbelt assembly according to claim 17 , wherein

the positioning mechanism includes an electronic motor connected to the controller, and

the controller is configured to operate the electronic motor during adjustment of the second member to the at rest position.

19. The vehicle seatbelt assembly according to claim 18 , wherein

the controller is configured to operate the electronic motor to release the second member such that the second member can move with respect to the first member in response to the controller operating the clutch mechanism to change from the engaged state to the dis-engaged state.