Shock absorbing height adjusters for restraint systems and associated systems and methods

1. A shock absorbing seatbelt adjuster, comprising:

a rail;

a seatbelt web receiver slidably engaged with the rail;

a stop engaged with the rail to a first side of the web receiver, wherein the stop is lockable at a plurality of stop positions along the rail;

a pre-loader engaged with the rail to a second side of the web receiver, opposite to the first side, wherein the pre-loader is lockable at a plurality of pre-load positions along the rail; and

a biasing member extending between the web receiver and the pre-loader, wherein the biasing member biases the web receiver toward the stop, and wherein the web receiver is slidable along the rail away from the stop in response to a force applied to the web receiver.

2. The shock absorbing seatbelt adjuster of claim 1 wherein the biasing member is a spring, and wherein movement of the pre-loader from a first pre-load position to a second pre-load position along the rail varies compression of the spring.

3. The shock absorbing seatbelt adjuster of claim 1 wherein movement of the stop from a first stop position to a second stop position varies a position of a web turning point defined by the web receiver.

4. The shock absorbing seatbelt adjuster of claim 1 wherein the rail includes a blocking portion positioned to limit movement of the web receiver away from the stop.

5. The shock absorbing seatbelt adjuster of claim 1 wherein the pre-loader includes an aperture, and wherein the rail extends through the aperture.

6. The shock absorbing seatbelt adjuster of claim 1 wherein the rail includes a plurality of openings, wherein individual openings correspond to individual stop positions, and wherein the stop includes a pin receivable in the individual openings to lock the stop at the associated stop position.

7. The shock absorbing seatbelt adjuster of claim 1 wherein the biasing member is a spring, wherein a first pre-load position corresponds to a first amount of compression of the spring, and wherein a second pre-load position corresponds to a second amount of compression of the spring, different than the first.

8. The shock absorbing seatbelt adjuster of claim 1 wherein the rail has a C-shaped cross-section and a plurality of openings, wherein individual openings correspond to individual pre-load positions, and wherein the pre-loader includes:

a pre-loader guide having a first rail opening shaped to enclose a section of the rail; and

a release button having a second rail opening shaped to enclose the section of the rail, wherein the release button is operable to disengage the pre-loader from individual openings to adjust an amount of pre-load.

9. A shock absorbing seatbelt height adjuster for a vehicle occupant restraint system, the shock absorbing seatbelt height adjuster comprising:

a rail;

a D-loop slidably coupled to the rail;

an adjustable stop slidably coupled to the rail and lockable at a plurality of positions along the rail; and

a biasing member positioned to urge the D-loop against the stop, wherein the biasing member is compressible to allow the D-loop to move away from the stop in response to tension in a seatbelt extending through the D-loop.

10. The shock absorbing seatbelt height adjuster of claim 9 wherein the plurality of positions comprise a first plurality of positions, the shock absorbing height adjuster further comprising a pre-loader slidably coupled to the rail and lockable at a second plurality of positions along the rail, wherein the pre-loader is releasably lockable at the second plurality of positions along the rail to vary a compression in the biasing member.

11. The shock absorbing seatbelt height adjuster of claim 10 wherein the pre-loader is shaped to enclose a section of the rail.

12. The shock absorbing seatbelt height adjuster of claim 9 wherein the stop is lockable at the plurality of positions to adjust a position of the D-loop.

13. The shock absorbing seatbelt height adjuster of claim 9 wherein the rail includes a tang positioned to engage the biasing member, and wherein the biasing member is compressed when the D-loop is positioned adjacent the stop.

14. The shock absorbing seatbelt height adjuster of claim 9 wherein the rail includes a C-shaped cross-section, and wherein the biasing member is positioned within the C-shaped cross-section.

15. The shock absorbing seatbelt height adjuster of claim 9 wherein the rail includes a means for limiting motion of the D-loop.

16. The shock absorbing seatbelt height adjuster of claim 15 wherein the means comprises a flange having a blocking portion.

17. A method for providing a seatbelt with shock absorption capabilities, the method comprising:

slidably coupling a web receiver to a rail;

operably coupling the seatbelt to the web receiver;

slidably coupling a stop to the rail to one side of the web receiver, wherein the stop is lockable at a plurality of stop positions along the rail;

slidably coupling a pre-loader to the rail to another side of the web receiver, opposite the one side, wherein the pre-loader is lockable at a plurality of pre-load positions along the rail; and

resiliently biasing the web receiver against the stop.

18. The method of claim 17 wherein biasing the web receiver includes positioning a spring between the stop and the pre-loader, and wherein the spring is compressible to provide the shock absorption capabilities via movement of the web receiver toward the pre-loader to compress the spring.

19. The method of claim 18 wherein slidably coupling the web receiver to the rail includes slidably coupling the web receiver to the rail between a blocking portion of the rail and the plurality of stop positions, and wherein the web receiver is slidable to compress the spring and engage the blocking portion.

20. The method of claim 17 wherein slidably coupling the pre-loader to the rail includes sliding the pre-loader over the rail such that the pre-loader encloses a section of the rail.