WO2009126149A1

WO2009126149A1 - Active head restraint system for a vehicle seat

Info

Publication number: WO2009126149A1
Application number: PCT/US2008/059650
Authority: WO
Inventors: Juergen Muenzberg
Original assignee: Lear Corporation
Priority date: 2008-04-08
Filing date: 2008-04-08
Publication date: 2009-10-15

Abstract

A vehicle head restraint system is provided with a support rod to be mounted to a seat back. A head restraint is supported by the support rod. The head restraint is moveable from a design position to an extended position to provide support to a head of an occupant. An active head restraint assembly is mounted to the support rod and supports the head restraint for moving the head restraint. The active head restraint assembly has an extension member mounted to the support rod and the head restraint to move the head restraint when activated. The extension member has pressurized gas provided therein for movement thereof. The active head restraint assembly has an actuator connected to the pressurized gas to activate the extension member.

Description

ACTIVE HEAD RESTRAINT SYSTEM FOR A VEHICLE SEAT

BACKGROUND OF THE INVENTION

1. Technical Field

The invention relates to active head restraint assemblies for vehicle seats.

2. Background Art

Vehicle seats are provided with moveable head restraints, which can move to accommodate a head of an occupant. One example of a vehicle seat having a movable head restraint is disclosed in U.S. Patent No. 6,983,989 Bl, which issued on January 10, 2006.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGURE l is a rear perspective view of an embodiment of a vehicle seat having a head restraint system in a design position;

FIGURE 2 is a side perspective view of a portion of the vehicle seat of Figure 1 with the head restraint system in the design position;

FIGURE 3 is a side perspective view of a portion of the vehicle seat of Figure 1 with the head restraint system in an intermediate position;

FIGURE 4 is a side perspective view of a portion of the vehicle seat of Figure 1 with the head restraint system in an extended position; FIGURE 5 is an enlarged rear perspective view of the head restraint system of Figure 1 in an extended position;

FIGURE 6 is a plan view of the head restraint system of Figure 1;

FIGURE 7 is a side perspective view of an embodiment of the vehicle head restraint system of Figure 1 ;

FIGURE 8 is an enlarged perspective view of the head restraint system of Figure 1 in the design position; and

FIGURE 9 is another perspective view of the head restraint system of Figure 1 in an extended position.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for the claims and/or as a representative basis for teaching one skilled in the art to variously employ embodiments of the present invention.

Referring to Figure 1, a vehicle seat is illustrated and referenced generally by numeral 10. The vehicle seat includes a seat bottom 12 to be secured to a floor of an associated vehicle for seating an occupant O upon the seat bottom 12, as illustrated. A seat back 14 extends from the seat bottom 12 and is secured relative to the seat bottom 12 for supporting a back of the occupant against the seat back 14. The seat back 14 may pivot relative to the seat bottom 12 to permit ingress and egress to and from a rear seating row and/or to permit an occupant to select a comfortable riding position while sitting in the vehicle seat 10.

In one embodiment, the seat back 14 includes a frame 16 for providing structural support for the seat back 14. Cushioning and a cover 18 may be mounted on the frame 16 to support the occupant. The cushioning may include foam, padding, bolsters and/or support wires. The cover 18 rests over the cushioning to conceal the cushioning. A portion of the cushioning and cover 18 are removed from the depicted embodiment to illustrate internal components of the seat back 14. Of course, any suitable cushioning and cover 18, such as those known in the art, may be mounted on the frame 16.

As illustrated, the vehicle seat 10 includes a head restraint system 20, which is supported by the seat back 14. The head restraint system 20 can be separately mounted to the seat back 14 or can be integrated with the seat back 14 in any suitable manner. In at least one embodiment, the head restraint system 20 can be moved vertically relative to the seat back 14 for height adjustment. In another embodiment, the head restraint system 20 is mounted to a rear shelf for a second row of seating of the vehicle interior. In another embodiment, the head restraint system 20 is mounted on a frame of the vehicle. Any suitable mounting for the head restraint assembly 20 is contemplated within the scope of the present invention.

As shown, the head restraint system 20 includes a support rod 22 to mount the head restraint system 20 to the seat back 14. In one embodiment, the support rod 22 has a first proximal end 24, a first longitudinal portion 26, a lateral portion 28, a second longitudinal portion 30, and a second proximal end 32 that are integrally formed. The first longitudinal portion 26 and the second longitudinal portion 30 are spaced apart by the lateral portion 28 to provide stability for the head restraint system 20. Although a single support rod 22 is depicted, any suitable amount of support rods 22 with any suitable orientation are contemplated within the scope of the present invention. For example, a pair of support rods 22 can be separately formed and mounted within the head restraint system 20. As seen in Figures 1-4, the support rod 22 supports an active head restraint assembly 34. In at least one embodiment, the active head restraint assembly 34 connects a head restraint 36 to the support rod 22. The head restraint 36 supports a head H of the occupant O. The head restraint 36 is moveable by the active head restraint assembly 34 between at least two positions. The motion of the head restraint 36 may be linear movement. Figures 1-2 illustrate the head restraint system 20 in a design position, which occurs under normal driving conditions. The head restraint 36 is moveable to an intermediate position, illustrated in Figure 3, and an extended position, illustrated in Figure 4, by the active head restraint assembly 34. The active head restraint assembly 34 minimizes a potential of injury for the occupant. The extended position, of Figure 4, may be any position with any movement of the head restraint 36 when compared to the design position, of Figures 1-2, while the intermediate position, Figure 3, may be any position between the design position and the extended position. In the extended position, depicted in Figure 4, the head restraint 36 may fully support the head H of the occupant O.

The active head restraint assembly 34 moves the head restraint 36 from the design position, as in Figures 1-2, to the intermediate position, illustrated in Figure 3, and further to the extended position, illustrated in Figure 4 to support the head H of the occupant O. The active head restraint assembly 34 helps to minimize whiplash injury to the occupant O by extending the head restraint 36 toward the head H of the occupant O. A whiplash injury occurs when the head H of the occupant O is over-extended during an impact condition. When the vehicle is impacted by another object, the vehicle seat 10 is accelerated into the occupant O, and the back B of the occupant moves a distance into the seat back 14. Accordingly, the head restraint 36 is moved toward the head H of the occupant O to support the head H to minimize the distance traveled by the head H of the occupant O to reduce the potential for injury to the occupant O.

As illustrated in Figure 1 , the head restraint 36 has a foam core 40 and a cover 42. The cover 42 rests over the foam core 40 to conceal the foam core 40. Of course, the head restraint 36 may be made out of any suitable material known in the art. Referring now to Figures 1 and 5-7, the active head restraint assembly 34 connects the head restraint 36 to the support rod 22 with an extension member 38. The extension member 38 moves the head restraint 36 from the design position to the extended position to support the head H of the occupant O. In at least one embodiment, the extension member 38 of the active head restraint assembly 34 extends the head restraint 36 from the design position in a first direction D₁ when an impact condition is detected in any suitable manner. In another embodiment, the extension member 38 extends the head restraint 36 from the design position when activated by the occupant in order to adjust the position of the head restraint 36 for increased occupant comfort. In one embodiment, the extension member 38 is a linear guide 38 to linearly extend the active head restraint assembly 34. The linear guide 38 contrains movement of the head restraint 36 so that the head restraint 36 only moves in the first direction D₁ or in a direction opposite D₁. The linear guide 38 allows for quick actuation of the head restraint 36 without unwanted friction caused by multiple degrees of freedom. Additionally, the linear guide 38 may not need to have a second linear guide 38; although any amount of linear guides 38 is contemplated within the scope of the present invention.

In one embodiment, the extension member 38 telescopes so that in the design position, the extension member 38 is compact and in the extended position, the extension member 38 is a specified length. Of course, the extension member 38 can telescope in any suitable manner known in the art. In at least one embodiment, illustrated in Figures 5-6, the extension member 38 telescopes by having a first cylinder 50 connected to the support 22 and a second cylinder 52 mounted to the head restraint 36. As shown, the first cylinder 50 is larger than the second cylinder 52 so that in the design position, the second cylinder 52 resides within the first cylinder 50, which is depicted in Figure 8.

The first cylinder 50 can be mounted to the support rod 22, as in

Figures 5-6, so that the extension member 38 can translate the head restraint 36 forward relative to the seat back 14. The head restraint 36 can be directly affixed and fixedly supported by the extension member 38. In another embodiment, the second cylinder 52 of the extension member 38 is mounted to the head restraint 36. Of course, any suitable extension member 38 can be utilized within the scope of the present invention.

A plate 39 may be mounted within the head restraint 36 to facilitate support and movement of the head restraint 36 by the extension member 38. The plate 39 forces the head restraint 36 to move upon actuation of the extension member

38. The plate 39 supports the head restraint 36 to increase stability of the head restraint 36. In at least one embodiment, the plate 39 fully supports the head restraint

36. The plate 39 can be mounted to the extension member 38 and that head restraint

36 in any suitable manner, such as with fasteners. Of course, the plate 39 can be made out of any suitable material, such as a metal.

With reference again specifically to Figures 2-4, the head restraint 36 is depicted having a front housing 64 and a rear housing 66. The front housing 64 generally provides structure to support the head H of the occupant O. The rear housing 66 is shown in phantom so that the active head restraint assembly 34 is more clearly visible. The rear housing 66 may be easily removed by the occupant O to reach a portion of the active head restraint assembly 34 concealed therein. The rear housing 66 is sized to cover extension member 38 and a portion of the active head restraint assembly 34 in the design position, intermediate position and the extended position. The rear housing 66 generally conceals a portion of the active head restraint assembly 36 to increase aesthetics of the head restraint system 20. The front housing 64 and the rear housing 66 may be made out of any suitable known material.

Referring now to Figures 1 and 5-7, the extension member 38 is connected to a pressurized gas source 44, so that when the pressurized gas source 44 is activated, the extension member 38 extends in the first direction D₁ to move the head restraint 36 from the design position to the extended position to support the head H of the occupant O. In one embodiment, the pressurized gas source contains pressurized carbon dioxide. Of course, any suitable pressurized gas is contemplated within the scope of the present invention. The extension member 38 may be connected to the pressurized gas source 44 by a cable 45 routed through the support rod 22. Of course, the extension member 38 can be connected to the pressurized gas source 44 in any suitable manner. In one embodiment, the pressurized gas source 44 is provided within the vehicle seat 10. In another embodiment, the pressurized gas source 44 is connected to the extension member 38 and mounted at a suitable location within the vehicle. Any suitable location for the pressurized gas source 44 is contemplated within the scope of the present invention.

In one embodiment, a pyrotechnical actuator 46 is connected between the pressurized gas source 44 and the extension member 38 so that the pyrotechnical actuator 46 releases a specified amount of pressurized gas from the pressurized gas source 44 to the extension member 38 to move the head restraint 36 a specified amount. The pyrotechnical actuator 46 is compact in size and is generally effective to release a specified amount of pressurized gas to the extension member 38. In at least one embodiment, the pyrotechnical actuator 46 is provided within the first proximal end 24 of the support rod 22 so that the head restraint system 20 is compact and the pyrotechnical actuator 46 is protected by the support rod 22.

As illustrated, a controller 48 is connected to the pyrotechnical actuator 46 to signal the pyrotechnical actuator 46 to release the pressurized gas from the pressurized gas source 44. The controller 48, may be mounted on the vehicle seat 10 or within the vehicle. In at least one embodiment, the controller 48 includes a limit switch 48. The limit switch 48 responds to a mechanical input provided by an input force received from the occupant, which exceeds a predetermined force. The limit switch 48 may be any suitable limit switch 48 known in the art. When the limit switch 48 is actuated, the limit switch 48 sends a signal to the pyrotechnical actuator 46.

In another embodiment, the controller 48 sends an electrical signal to the pyrotechnical actuator 46 when a predetermined event actuates the controller 48.

A non-limiting example of the predetermined event is when the seat back 14 receives a force of the occupant against the seat back 14. In another example, the predetermined event is an impact on the front or rear bumper of the vehicle, which is detected by sensors. Any suitable manner of determining a predetermined event has occurred and then sending a signal from the controller 48 to the pyrotechnical actuator 46 such as those known in the art is contemplated within the scope of the present invention.

The controller 48 is activated, for example, when the vehicle is impacted by another object thereby accelerating the seat back 14 into the occupant and creating an impact condition. The impact condition may be generated from a rear impact. Likewise, the impact condition may be generated from a forward impact wherein the occupant rebounds from a seat harness or other mechanism, into the vehicle seat 10. If the force of the occupant exceeds a predetermined force, then the controller 48 sends a signal to the pyrotechnical actuator 46 to actuate the active head restraint assembly 20. In another embodiment, the activation of the controller 48 is generated when the vehicle exceeds a predetermined acceleration before the impact condition occurs.

In another embodiment, the controller 48 is activated by an output of a sensor provided in the vicinity of a bumper of the vehicle such that the sensor detects an impending impact and then activates the controller 48. Any suitable sensor such as those known in the art may be employed. In yet another embodiment, the controller 48 is activated by an output of a limit switch, which detects a possible external impact. In still another embodiment, the controller 48 is activated by an output of an inertia switch such that a specified change in momentum of the vehicle causes the inertia switch to activate the controller 48.

In yet another embodiment, the controller 48 is provided so that an occupant O can actuate the controller 48 to adjust the position of the head restraint 36. The controller 48 may signal the pyrotechnical actuator 46 to allow a small amount of pressurized gas to be released from the pressurized gas source 44 so that the head restraint 36 movement is not large. Of course, any suitable controller 48 is contemplated within the scope of the present invention. With reference now to Figures 8-9, a locking mechanism 54 of the active head restraint assembly 34 is illustrated. The locking mechanism 54 can lock the active head restraint assembly 26 in the extended position illustrated or any desired position. While the extension member 38 moves the head restraint 36 from the design position though the intermediate position to the extended position, the locking mechanism 54 does not restrict and/or hinder motion. Once the extension member 38 no longer moves the head restraint 36, such as when the head of the occupant has contacted the head restraint 36, the locking mechanism 54 engages to keep the head restraint 36 in the extended position until the locking mechanism 54 is disengaged and/or reset to allow the head restraint 36 to return to the design position. As illustrated, the locking mechanism 54 includes a shaft 56 with a plurality of teeth 58 formed therein. The shaft 56 is moveable in each of the directions that the extension member 38 is moveable. In the design position, illustrated in Figure 8, the shaft 56 is retracted and in the extended position, illustrated in Figure 9, the shaft 56 extends as the extension member 38 extends. The teeth 58 of the shaft 56 interact with a portion of the locking mechanism 54 to allow motion from the design position toward the extended position and resist motion from the extended position toward the design position in any suitable manner. In one embodiment, the locking mechanism 54 is a rachet 54.

As illustrated, an unlocking mechanism 60 interacts with the locking mechanism 54 to unlock the locking mechanism 54 and allow movement of the head restraint 36. In at least one embodiment, the unlocking mechanism 60 is mounted on the locking mechanism 54 to disengage the portion of the locking mechanism 54 from one of the teeth 58. Disengagement of the locking mechanism 54 by the unlocking mechanism 60 allows the head restraint 36 to be moved either automatically or manually. As illustrated, the unlocking mechanism 60 may include a push pin 60 that the occupant can push, which subsequently disengages the engaged portion of the locking mechanism 54 from the teeth 58.

The unlocking mechanism 60 may extend beyond an outer surface of the head restraint 36, as depicted in Figure 7, so that the occupant can manually reset the head restraint system 20 after actuation thereof. The unlocking mechanism 60 allows for a simple reset of the active head restraint assembly 34 when compared to resetting prior art active head restraint assemblies. The simple reset of the present invention decreases production costs for the head restraint system 20 and does not require the occupant to have a professional reset and reassemble the active head restraint assembly 34, saving time and money. Of course, any suitable unlocking mechanism 60 is contemplated within the scope of the present invention.

Once the unlocking mechanism 60 disengages the locking mechanism 54, the head restraint 36 may be manually moved by the occupant from the extended position to the design position. In another embodiment, a biasing member 68 is mounted between the support shaft 22 and the head restraint 36 to return the head restraint 36 to the design position. The biasing member 60 biases the head restraint 36 toward the support shaft 22. When the occupant actuates the unlocking mechanism 60 to disengage the locking mechanism 54, the head restraint 36 moves automatically toward the support rod 22. Any suitable biasing member 60 may be utilized. In one embodiment, a pair of biasing members 60 is provided on opposing sides of the extension member 38, as illustrated in Figure 6.

Still referring to Figure 6, a support member 62 is illustrated. The support member 62 is mounted on the support rod 22 and is supports the extension member 38 to increase stability of the head restraint system 20. In one embodiment, the support member 62 is mounted directly to the extension member 38. In the illustrated embodiment, the support member 62 is mounted to the locking mechanism 54, which is mounted on the extension member 34. Any suitable support member 62 is contemplated within the scope of the present invention to increase stability of the head restraint system 20.

While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.

Claims

WHAT IS CLAIMED IS:

1. A vehicle head restraint system for a vehicle seat, the vehicle head restraint system comprising: a support rod adapted to be mounted to a seat back of a vehicle seat; a head restraint supported by the support rod, the head restraint being moveable relative to the seat back in from a design position to an extended position to provide support to a head of an occupant; and an active head restraint assembly mounted to the support rod and supporting the head restraint for moving the head restraint to the extended position, the active head restraint assembly having: a linear guide mounted to the support rod and the head restraint to directly move the head restraint from a design position to the extended position when the active head restraint assembly is activated, the linear guide being connected to a pressurized gas source to move the linear guide, and a pyrotechnical actuator connected to the pressurized gas source to activate the linear guide.

2. The vehicle head restraint system of claim 1 wherein the linear guide of the active head restraint assembly is formed from at least a pair of cylinders that overlap in the design position to decrease sizing of the linear guide and head restraint.

3. The vehicle head restraint system of claim 1 wherein the active head restraint assembly further comprises at least one biasing member connected to the support rod and the head restraint to return the head restraint to the design position from the extended position.

4. The vehicle head restraint system of claim 1 wherein the active head restraint assembly is configured to be activated during an impact condition.

5. The vehicle head restraint system of claim 1 wherein the active head restraint assembly is configured to be activated by an occupant.

6. The vehicle head restraint system of claim 1 further comprising a locking mechanism to lock the head restraint in the extended position.

7. The vehicle head restraint system of claim 6 wherein the locking mechanism is further defined as a ratchet.

8. The vehicle head restraint system of claim 6 further comprising an unlocking mechanism provided on an exterior of the head restraint to unlock the locking mechanism when activated to allow the head restraint to return to the design position.

9. The vehicle head restraint system of claim 7 wherein the unlocking mechanism further comprises a push button provided on an exterior of the head restraint such that depression of the push button unlocks the locking mechanism.

10. The vehicle head restraint system of claim 1 wherein the head restraint further comprises a front housing mounted on the active head restraint assembly to support the head of the occupant and a rear housing supported by the front housing to cover at least a portion of the active head restraint assembly.

11. The vehicle head restraint system of claim 1 wherein the active head restraint assembly is mounted directly to the support rod.

12. The vehicle head restraint system of claim 1 wherein the pyrotechnical actuator of the active head restraint assembly is provided on the support rod.

13. The vehicle head restraint system of claim 12 wherein the pyrotechnical actuator of the active head restraint assembly is mounted to a proximal end of the support rod within a housing.

14. The vehicle head restraint system of claim 12 wherein the pyrotechnical actuator of the active head restraint assembly is connected to the linear guide with a cable member provided within the support rod.

15. The vehicle head restraint system of claim 1 further comprising a support member mounted to the support rod to stabilize the locking mechanism.

16. The vehicle head restraint system of claim 1 wherein the linear guide has a plate mounted thereon to connect the linear guide to the head restraint and fully support the head restraint.

17. A vehicle head restraint system for a vehicle seat, the vehicle head restraint system comprising: a support rod adapted to be mounted to a seat back of a vehicle seat; a head restraint supported by the support rod, the head restraint being moveable relative to the vehicle seat back in at least two directions to at least an extended position along one of the at least two directions to provide support to a head of an occupant; and an active head restraint assembly mounted to the support rod and supporting the head restraint for moving the head restraint to the extended position, the active head restraint assembly having: an extension member mounted to the support rod and the head restraint to move the head restraint from a design position to the extended position when the active head restraint assembly is activated, the extension member being connected a pressurized gas source to move the extension member, a locking mechanism to lock the head restraint in the extended position, and an actuator connected to the pressurized gas source to activate the extension member.

18. The vehicle head restraint system of claim 17 wherein extension member is telescoping to decrease sizing of the extension member and head restraint in the design position.

19. A vehicle seat comprising: a seat back adapted to be mounted within a vehicle; a support rod adapted to be mounted to the seat back; a head restraint supported by the support rod, the head restraint being moveable relative to the seat back in at least two directions to at least an extended position along one of the at least two directions to provide support to a head of an occupant; and an active head restraint assembly mounted to the support rod and supporting the head restraint for moving the head restraint to the extended position, the active head restraint assembly having: a telescoping extension member mounted to the support rod and the head restraint to move the head restraint from a design position to the extended position when the active head restraint assembly is activated, the extension member being connected to a pressurized gas source to move the extension member, a locking mechanism to lock the head restraint in the extended position, an unlocking mechanism provided on an exterior of the head restraint to unlock the locking mechanism when activated, a pyrotechnical actuator connected to the extension member to activate the extension member, and a biasing member connected to the support rod and the head restraint to return the head restraint to the design position from the extended position.

20. The vehicle seat of claim 19 wherein the active head restraint assembly further comprises a controller in operative connection with the pyrotechnical actuator such that the controller sends a signal to the pyrotechnical actuator so that the pyrotechnical actuator actuates the pressurized gas source to extend the extension member and the head restraint to the extended position.