Load limiting seatbelt retractor

• US 10,562,488 B2
• Filed: 05/03/2017
• Issued: 02/18/2020
• Est. Priority Date: 05/03/2017
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Faruque, Mohammed Omar, Cheng, James Chih, McCoy, Robert William, Barbat, Saeed David, Jaradi, Dean M.
• Primary Examiner(s): Kim, Sang K
• Application Number:
  US15/585,599
• Publication Number:
  US 20180319362A1
• Time in Patent Office: 1,021 Days
• CPC Class Codes: B60R 2022/282 using fluids or vico-elastic materials
• CPC Class Codes: B60R 22/341 comprising energy-absorbing means
• CPC Class Codes: B60R 22/36 self-locking in an emergency B60R22/3405 , B60R22/343 take precedence
• CPC Class Codes: F16F 2222/08 Inertia
• CPC Class Codes: F16F 2224/046 pneumatic
• CPC Class Codes: F16F 2224/048 High viscosity, semi-solid pastiness F16F2224/041 takes precedence
• CPC Class Codes: F16F 9/06 using both gas and liquid F16F9/486 take precedence; self-pumping fluid springs B60G17/044
• CPC Class Codes: F16F 9/10 using liquid only; using a fluid of which the nature is immaterial
• CPC Class Codes: F16F 9/30 with solid or semi-solid material, e.g. pasty masses, as damping medium in devices where rotary elements are damped by viscous shear effect only, any throttling effect being immaterial F16F9/12; where members moving with a rotating system are being damped F16F15/16

Abstract

A seatbelt retractor includes a base, a spool, a cylinder and a cylinder lock. The spool is rotatably coupled to the base and has a piston portion. The cylinder is engaged with the piston portion and therewith defines a first chamber. The piston portion is movable from a first position yielding a first chamber volume to a second position yielding a second chamber volume. The cylinder lock in a first condition rotatably fixes the cylinder to the base. Damping fluid is disposed in the chamber.

Claims

1. A seatbelt retractor comprising:

a base;

a spool rotatably coupled to the base and including a piston portion;

a cylinder engaged with the piston portion and therewith defining a first chamber, the piston portion movable from a first position yielding a first chamber volume to a second position yielding a second chamber volume;

a cylinder lock in a first condition rotatably fixing the cylinder to the base; and

a damping fluid in the chamber;

wherein the damping fluid is a heterogeneous mixture including hydrophobic nanoporous particles and a liquid; and

wherein the piston portion has piston threads and the cylinder has cylinder threads and the piston threads and the cylinder threads are in threaded engagement with each other and further wherein a combination of a pitch of the threads and a constitution of the particles and a volume of the chamber allow the spool to rotate twice before the fluid becomes substantially incompressible.

2. The seatbelt retractor of claim 1, wherein the spool defines an axis of rotation, the piston portion is centered on the axis of rotation, and the cylinder is centered on the axis of rotation.

3. The seatbelt retractor of claim 2, wherein the piston portion has piston threads and the cylinder has cylinder threads and the piston threads and the cylinder threads are in threaded engagement with each other.

4. The seatbelt retractor of claim 3, wherein the cylinder receives the piston portion with the cylinder threads being formed on an inside diameter of the chamber and the piston threads are formed on an outside diameter of the piston portion.

5. The seatbelt retractor of claim 1, wherein the cylinder lock includes:

a plurality of clutching teeth disposed on an outer circumference of the cylinder for rotation therewith; and

an engagement mechanism fixed in part to the base and including an engagement tooth, the engagement tooth in the first condition being in engagement with the clutching teeth and the engagement tooth in a second condition being not in engagement with the clutching teeth,

wherein engagement of the engagement tooth with the clutching teeth rotatably fixes the cylinder to the base.

6. The seatbelt retractor of claim 1, wherein the particles have nanopores, and in the first position of the piston portion the nanopores are substantially filled with a gas and in the second position of the piston portion the nanopores are substantially filled with the liquid.

7. The seatbelt retractor of claim 1, wherein the heterogeneous mixture is a colloid of hydrophobic nanoporous particles in the liquid.

8. The seatbelt retractor of claim 1, wherein the particles are formed of silica.

9. The seatbelt retractor of claim 8, wherein the particles have a hydrophobic surface treatment.

10. The seatbelt retractor of claim 1, wherein a volume of the heterogeneous mixture when the piston portion is in the second position is at most half of the volume of the heterogeneous mixture when the piston portion is in the first position.

11. The seatbelt retractor of claim 10, wherein the mixture is constituted to allow a return to the volume in the first position when the first chamber volume is restored.

12. The seatbelt retractor of claim 1, further comprising a supplementary capsule sealingly fixed to the cylinder defining a second chamber and an aperture disposed between and connecting the first chamber and the second chamber.

13. The seatbelt retractor of claim 12, wherein the second chamber is substantially filled with a gas when the piston portion is in the first position and the second chamber is substantially filled with the fluid when the piston portion is in the second position.

14. The seatbelt retractor of claim 12, further comprising a valve disposed over the aperture.

15. The seatbelt retractor of claim 12, wherein the damping fluid is a heterogeneous mixture including hydrophobic nanoporous particles and a liquid.

16. The seatbelt retractor of claim 15, wherein the aperture is sized to block a flow of the mixture therethrough at a first pressure associated with the first position of the piston portion.

17. The seatbelt retractor of claim 16, wherein the heterogeneous mixture is a colloid of hydrophobic nanoporous particles in a liquid.

18. The seatbelt retractor of claim 16, wherein the particles are formed of silica and the particles have a hydrophobic surface treatment.

19. A seatbelt retractor comprising:

a base;

a spool rotatably coupled to the base and including a piston portion;

a cylinder engaged with the piston portion and therewith defining a first chamber, the piston portion movable from a first position yielding a first chamber volume to a second position yielding a second chamber volume;

a cylinder lock in a first condition rotatably fixing the cylinder to the base; and

a damping fluid in the chamber;

wherein the spool defines an axis of rotation, the piston portion is centered on the axis of rotation, and the cylinder is centered on the axis of rotation; and

wherein the piston portion has piston threads and the cylinder has cylinder threads and the piston threads and the cylinder threads are in threaded engagement with each other.

20. A seatbelt retractor comprising:

a base;

a spool rotatably coupled to the base and including a piston portion;

a cylinder engaged with the piston portion and therewith defining a first chamber, the piston portion movable from a first position yielding a first chamber volume to a second position yielding a second chamber volume;

a cylinder lock in a first condition rotatably fixing the cylinder to the base;

a damping fluid in the chamber; and

a supplementary capsule sealingly fixed to the cylinder defining a second chamber and an aperture disposed between and connecting the first chamber and the second chamber.