VARIABLE LOAD LIMITING DEVICE FOR SEATBELT RETRACTOR TO REDUCE OCCUPANT INJURY

• US 20100007125A1
• Filed: 07/09/2008
• Published: 01/14/2010
• Est. Priority Date: 07/09/2008
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Jessup, Andrew D., Thomas, Chuck
• Granted Patent: US 7,828,331 B2
• Time in Patent Office: Days
• US Class Current: 280/805
• CPC Class Codes: B60R 2022/282 using fluids or vico-elastic materials
• CPC Class Codes: B60R 22/3413 operating between belt reel and retractor frame B60R22/4676 takes precedence
• CPC Class Codes: F16F 9/145 involving only rotary movement of the effective parts wing closers or openers with fluid brakes of the rotary type E05F3/14
• CPC Class Codes: F16F 9/53 Means for adjusting damping characteristics by varying fluid viscosity, e.g. electromagnetically F16F13/30 takes precedence; brakes comprising a medium with electrically or magnetically controlled friction F16D57/002; electrorheological fluids per se C10M171/001; magnetorheological fluids per se H01F1/447

Abstract

A variable load limiting device for a vehicle safety belt assembly is provided for controllably restraining a vehicle occupant by the vehicle safety belt assembly during deceleration of a vehicle. The device includes a body including a fluid chamber for containing a free-flowing fluid therein. A wiper assembly is operably disposed in the fluid chamber and selectively coupled to the vehicle safety belt assembly. The wiper assembly creates a pressure differential within the fluid chamber when a force in excess of a predetermined value is applied to the vehicle safety belt assembly. A throttle valve is operably connected to the body for controlling fluid pressure in the fluid chamber.

Claims

1. A variable load limiting device for a vehicle safety belt assembly for controllably restraining a vehicle occupant by the vehicle safety belt assembly during deceleration of a vehicle, the device comprising:

a body including a first fluid chamber in selective communication with a second fluid chamber, each fluid chamber containing a free-flowing fluid therein wherein the body includes a wall, an inner surface of the wall at least partially defines the first fluid chamber, an outer surface of the wall at least partially defines the second fluid chamber;

a wiper assembly operably disposed in the first fluid chamber and selectively coupled to the vehicle safety belt assembly, the wiper assembly creating a pressure differential within the first fluid chamber when a force in excess of a predetermined value is applied to the vehicle safety belt assembly; and

a throttle valve operably connected to the body for controlling fluid pressure in the first fluid chamber wherein the throttle valve is located between the fluid chambers, the throttle valve controlling fluid pressure in the first fluid chamber by selectively allowing fluid flow between the fluid chamber and the second fluid chamber, the throttle valve opens to bleed fluid from the first fluid chamber to the second fluid chamber as the wiper assembly rotates and a drop in fluid pressure of the first fluid chamber allows fluid that was bled into the second fluid chamber back into the first fluid chamber.

4. The variable load limiting device of claim 1, wherein the body includes a first housing and a second housing, the first housing at least partially defining the first fluid chamber, the second housing at least partially defining the second fluid chamber.

5. The variable load limiting device of claim 4, wherein the first housing includes a first longitudinal axis and the second housing includes a second longitudinal axis, the first axis being generally coincident with the second axis.

6. The variable load limiting device of claim 4, wherein the second housing at least partially surrounds the first housing.

8. The variable load limiting device of claim 1, wherein the wiper assembly includes a wiper moveably located in the first fluid chamber.

9. The variable load limiting device of claim 8, wherein the variable load limiting device further comprises a clutch, an input of the clutch is operably connected to a retractor of the vehicle safety belt assembly and an output of the clutch is operably connected to the wiper.

10. The variable load limiting device of claim 1, further comprising a load control operably connected to the throttle valve, the load control adjusting the throttle valve as a function of vehicle crash-related data.

11. The variable load limiting device of claim 1, wherein the pressure differential in the first fluid chamber created by activation of the wiper assembly returns the load limiting device to a state which is substantially similar to a state prior to activation of the load limiting device whereby the load limiting device may be activated a plurality of times.

2-3. -3. (canceled)

7. (canceled)

12. A vehicle safety belt assembly for controllably restraining a vehicle occupant during deceleration of a vehicle, the vehicle safety belt assembly comprising:

a retractor for winding up a safety belt; and

a variable load limiting device including;

a body including a first fluid chamber and a second fluid chamber each containing fluid,

a wiper assembly connected to the body, the wiper assembly including a wiper rotatably disposed in the at least one fluid chamber, and

a throttle valve connected to the body for controlling fluid pressure in the at least one fluid chamber, the throttle valve being configured to allow fluid to pass from the first fluid chamber to the second fluid chamber and to allow fluid to pass from the second fluid chamber to the first fluid chamber;

wherein when a force applied to the retractor exceeds a predetermined value, the retractor engages the wiper assembly, the wiper rotates in the at least one fluid chamber creating a volume of high pressure within the at least one fluid chamber which resists and absorbs a portion of the applied force.

13. The vehicle safety belt assembly of claim 12, further including a centrifugal clutch operably connecting the retractor to the wiper assembly.

14. The vehicle safety belt assembly of claim 12, further comprising a load control operably connected to the throttle valve, the load control adjusting the throttle valve as a function of vehicle crash-related data.

15. The vehicle safety belt assembly of claim 12, wherein the first fluid chamber is separated from the second fluid chamber by the throttle valve.

16. The vehicle safety belt assembly of claim 15, wherein the body includes a wall at least partially defining the first and second fluid chambers.

17. The vehicle safety belt assembly of claim 12, wherein the volume of high pressure within the at least one fluid chamber returns the wiper to a state which is substantially similar to a state prior to rotation of the wiper.

18-20. -20. (canceled)

21. A vehicle safety belt assembly comprising:

a retractor for winding up a safety belt;

a clutch having an input and an output, the input being operably connected with the retractor;

a body including a first fluid chamber in selective communication with a second fluid chamber, each chamber containing a fluid;

a throttle valve disposed in a fluid passage connecting the first and second fluid chambers, the throttle valve selectively allowing fluid flow between the first chamber and the second chamber;

a wiper assembly located in the first fluid chamber and selectively coupled to the vehicle safety belt assembly, the wiper assembly including a wiper operably connected to the output of the clutch and sealingly engaging an inner surface of a wall defining the first fluid chamber, as the wiper rotates within the first fluid chamber fluid in the first fluid chamber is moved toward the throttle valve and bleeds through the throttle valve from the first fluid chamber to the second fluid chamber, wherein a drop in fluid pressure of the first fluid chamber allows fluid that was bled into the second fluid chamber back into the first fluid chamber through the throttle valve.

22. The device of claim 21, wherein the second fluid chamber contains hydraulic fluid and a compressible gas, as fluid is bled into the second fluid chamber from the first fluid chamber via the throttle valve, the hydraulic fluid compresses the gas.

23. The device of claim 21, wherein the wiper assembly is in an original position prior to activation of the wiper assembly and a pressure differential between the first chamber and the second chamber created by activation of the wiper assembly draws the wiper assembly back to the original position upon disengagement of the clutch with the wiper assembly.

24. The device of claim 21, wherein the wiper assembly and a radial wall extending inwardly from the body into the first fluid chamber together define a first fluid chamber low pressure zone, wherein no hydraulic fluid is contained in the first fluid chamber low pressure zone.

25. The device of claim 21, further comprising a return spring in the first chamber, wherein the wiper assembly is in an original position prior to activation of the wiper assembly and the return spring induces the wiper to return to the original position.