The present disclosure relates to a vehicle seat assembly. The present disclosure relates particularly, but not exclusively to a vehicle seat assembly; and to a vehicle having a vehicle seat assembly.
A front seat of a vehicle benefits from having adjustments provided to allow for varying size occupants. Typically a modern front seat will have at least track, height and seat back angle mechanisms. As the seat must provide a high degree of structural integrity (to protect the occupant during an impact) the mechanism thus forms part of the structural load path and so must be quite substantial in construction. There is an ongoing need to develop vehicle seats that may meet these criteria. It is against this backdrop that the present invention has been conceived.
Aspects and embodiments of the present invention relate to a vehicle seat assembly; and to a vehicle having a vehicle seat assembly as claimed in the appended claims.
According to an aspect of the present invention there is provided a vehicle seat assembly comprising: a backrest support comprising a first torsion tube for adjusting a recline angle; and a chassis comprising a second torsion tube for adjusting height rise; wherein the first and second torsion tubes are arranged concentrically about a pivot axis. The first torsion tube may be disposed within the second torsion tube; or the second torsion tube may be disposed within the first torsion tube. The pivot axis is a common axis about which the first and second torsion tubes may rotate. The first and second torsion tubes may be rotated independently of each other about said pivot axis. Thus, the height rise of the chassis and the recline angle of the backrest support may be adjusted independently. The first and second torsion tubes have a common longitudinal axis. This has allowed the vehicle seat assembly to utilise concentric torsion tubes. The first and second torsion tubes may work together to provide increased bending stiffness. At least in certain embodiments, this arrangement helps to conserve space. The resulting kinematic architecture is suitable for mounting composite seat squab assemblies, but could be used with other seat frame configurations.
The angular orientation of the first and second torsion may be adjusted to change the seat geometry. The angular orientation of the first torsion tube is adjustable to adjust recline angle. The angular orientation of the second torsion tube is adjustable to adjust height rise. The angular orientation of the first and second torsion tubes may be adjusted independently to enable the height rise and recline angle to be adjusted independently. At least in certain embodiments, the first torsion tube is disposed inside the second torsion tube. In a variant, the vehicle seat assembly could be configured such that the second torsion tube is disposed inside the first torsion tube.
The chassis may comprise first and second rear mounting arms; and first and second front mounting arms. The front and rear mounting arms may be pivotally mounted to first and second carrier elements. First and second lateral members may be supported by the front and rear mounting arms. The first and second lateral members may support a seat pan.
The first torsion tube may be rotatable about the pivot axis to adjust the recline angle. The first torsion tube may provide a connection between the chassis and the backrest support. The first torsion tube may be rotatable relative to first and second lateral members of the chassis. The backrest support may comprise at least one mounting plate. The first torsion tube may be fixedly connected to said at least one mounting plate. The at least one mounting plate attaches the backrest support to the first torsion tube.
The vehicle seat assembly may include a first actuator for rotating the first torsion tube about said pivot axis. The first actuator may be operated to adjust the angular orientation of the first torsion tube, thereby adjusting the recline angle. A transfer arm may be fixedly mounted to the first torsion tube. The first torsion tube may be controlled in rotation by the transfer arm. The transfer arm may comprise a transfer bracket or other rigid member. The first actuator may drivingly engage the transfer arm. The transfer arm may be connected to a drive rack which engages a first output pinion coupled to the actuator. The drive rack may comprise a toothed quadrant which meshes with the first output pinion. The transfer arm may be attached to one end of the first torsion tube. An additional transfer arm may be attached to the opposite end of the first torsion tube. The transfer arm may comprise a deformable link.
The transfer arm may comprise a load limiting device, such as a deformable link. A deformable link may be disposed in the load-path between the drive rack and the first torsion tube. The deformable link may be configured to deform in a predetermined manner under load. Under seat-back load, the first torsion tube is forced into rotation about the second torsion tube. This force may be resisted initially at the pinion gear coupled to one end of the first torsion tube. Further loading may cause the deformable link to activate and allow continued rotation until the drive rack engages a first chassis frame member. At this point a reaction arm at the opposite end of the first torsion tube may contact a second chassis frame member and the first torsion tube is no longer acting to resist significant torque as both ends now have similar reaction conditions. The outcome of this sequence of events is a tuneable and controlled absorption of energy through managed component deflection. This is of particular importance when considering a seat back assembly which is manufactured in part or substantially from plastic and/or composite materials. However, it will be understood that the vehicle seat assembly according to the present invention is not limited in this respect.
The first actuator may comprise a manually operated actuator, such as a rotary knob or a handle. Alternatively, the first actuator may comprise a first electric motor.
The second torsion tube is rotatable about the pivot axis to adjust the rise height.
The chassis may comprise first and second rear mounting arms. The second torsion tube may be fixedly connected to at least one of said first and second rear mounting arms. Rotating the second torsion tube may adjust the angular orientation of the first and second rear mounting arms, thereby adjusting the rise height. The second torsion tube may be connected to each rear mounting arm.
The vehicle seat assembly may comprise a second actuator for rotating the second torsion tube about the pivot axis. The second actuator may be operated to adjust the angular orientation of the second torsion tube, thereby adjusting the rise height. The angular orientation of the second torsion tube (and therefore of the first and second rear mounting arms) may be adjusted relative to first and second lateral members of the chassis. The second actuator may be mounted to the chassis. The second actuator may be mounted to one of the first and second lateral members.
The second actuator could comprise a manually operated actuator, such as a rotary knob or a handle. Alternatively, the second actuator may comprise a second electric motor.
According to a further aspect of the present invention there is provided a vehicle comprising at least one vehicle seat assembly as described herein.
Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment may be combined in any way and/or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.
One or more embodiments of the present invention will now be described, by way of example only, with reference to the accompanying Figures, in which:
A vehicle seat assembly 1 in accordance with an embodiment of the present invention is shown in
The vehicle seat assembly 1 comprises a squab (backrest) assembly 2 and a base assembly 3. The squab assembly 2 comprises a padded squab 4 mounted to a backrest support 5. The base assembly 3 comprises a seat cushion 6 supported on a seat cushion pan (not shown) mounted to a chassis 7. The squab assembly 2 is pivotally mounted to the base assembly 3 and pivots about a pivot axis A. The pivot axis A is disposed below a H-point of a seat occupant (i.e. below the theoretical location of a pivot point between the torso and upper leg of the seat occupant). The chassis 7 is slidably mounted to a pair of parallel rails 8 fixedly mounted to a floor of the vehicle V. A perspective view of the backrest support 5 and the chassis 7 is shown in
The backrest support 5 comprises first and second beams 9, 10 fixedly mounted to respective ends of a first torsion tube 11. The first and second beams 9, 10 each have an I-section and are moulded from a short-fibre reinforced thermoplastic material. In use, the first and second beams 9, 10 extend generally vertically within the squab assembly 2. As shown in
As shown in
With reference to
With reference to
The vehicle seat assembly 1 comprises a rise height control mechanism 32 for controlling a rise height of the base assembly 3. The rise height control mechanism 32 comprises a second actuator in the form of a second drive motor 33 (see
The vehicle seat assembly 1 comprises a travel control mechanism 36 for controlling the longitudinal position of the base assembly 3. As shown in
The vehicle seat assembly 1 may optionally also include an incline control mechanism for controlling an incline of the base assembly 3. The incline control mechanism is not shown in the present embodiment.
The deformable link 30 is adapted to deform in a controlled manner to absorb energy in the event of a collision. In the present embodiment, the deformable link 30 is a metal plate. The deformable link 30 is rigid (i.e. may not be deformed) upon application of loads up to a design load threshold. Upon application of a load exceeding the design load threshold, the deformable link 30 is configured to undergo progressive plastic deformation. As shown most clearly in
The first drive rack 29 is connected to the deformable link 30. The first drive rack 29 may be formed integrally with the deformable link 30 or may be fixedly mounted thereto, for example by welding. The width of the first drive rack 29 may optionally be greater than that of the deformable link 30 to form a stepped section 45. The first drive rack 29 defines a cooperating surface 46 for cooperating with a reaction surface 47 defined by a leading edge of the constraining member 44. The cooperating surface 46 and the reaction surface 47 have complementary part-circular (arcuate) profiles each having a centre of curvature coincident with the pivot axis A. If the deformable link 30 is deformed, the reaction surface 47 is operative to maintain the first drive rack 29 in engagement with the first output pinion gear 28.
In the present embodiment, the transfer bracket 42 is configured to cooperate with a latching mechanism 48 provided on the first mounting plate 12. The latching mechanism 48 comprises a movable pawl 49 for releasably engaging a detent 50 formed in an upper portion of the transfer bracket 42. The latching mechanism 48 allows the squab assembly 2 to be selectively decoupled from the base assembly 3 to pivot forwards. This decoupling arrangement is typically employed to facilitate ingress to a rear seat of the vehicle V, for example in a coupe body style, but the latching mechanism 48 may be omitted if this functionality is not required. In certain embodiments, a second latching mechanism may be provided on the second mounting plate 13.
A pivot bracket 51 is fixedly mounted to a second end of the first torsion tube 11 for limiting the pivoting motion of the squab assembly 2. The pivot bracket 51 comprises first and second prongs 52, 53 angularly offset from each other to define a pivot range for the squab assembly 2. As shown most clearly in
As shown in
The operation of the vehicle seat assembly 1 will now be described with reference to the figures. In normal use, the first drive motor 27 is operable to adjust the recline angle of the squab assembly 2. The first drive motor 27 drivingly rotates the first output pinion gear 28 which meshes with the first drive rack 29 disposed on the deformable link 30. The resulting rotational movement of the first drive rack 29 rotates the first torsion tube 11 about the pivot axis A. The rotation of the first torsion tube 11 transmits torque to the first mounting plate 12 causing the squab assembly 2 to pivot about the pivot axis A. The first drive motor 27 may be reversed to change the rotational direction of the first output pinion gear 28, thereby enabling the recline angle of the squab assembly 2 to be increased or decreased.
The second drive motor 33 is operable to adjust the rise height of the base assembly 3. The second drive motor 33 drivingly rotates the second output pinion gear 34 which drives the second drive rack causing the drive arm 35 to pivot about the pivot axis A. The resulting rotation of the second torsion tube 18 changes the geometry of the base assembly 3 causing the rise height to increase or decrease depending on the direction of rotation of the second drive motor 33.
The third drive motor 37 is operable to adjust the longitudinal travel of the base assembly 3 along the rails 8.
In the event of a force being applied to the squab assembly 2, for example a collision force resulting from a dynamic collision event, a torque is applied to the first torsion tube 11 resulting in the application of a shear force on the deformable link 30. If the shear force exceeds a threshold level (determined by the configuration of the deformable link 30), the deformable link 30 is predisposed to undergo plastic deformation. The deformation of the deformable link 30 absorbs collision energy rather than transmitting the loads directly into the base assembly 3 by means of the first output pinion gear 28 (thus reducing load on the first output pinion gear 28). Moreover, deformation of the deformable link 30 provides progressive deceleration of the squab assembly 2, thereby helping to reduce the peak loads transmitted to a seat occupant. As described herein, the deformable link 30 is disposed between the first lateral member 16 and the constraining member 44. Thus, deformable link 30 is constrained so as to undergo in-plane deformation. The reaction surface 47 defined by the constraining member 44 cooperates with the cooperating surface 46 to maintain the first drive rack 29 in engagement with the first output pinion gear 28.
The deformable link 30 rotates about the pivot axis A and the arcuate motion is maintained during deformation by the constraining member 44. The deformable link 30 is configured to deform under bending, reaching the yield stress of the materials resulting in localised plastic (permanent) deformation. The cooperating surface 46 cooperates with the reaction surface 47 of the constraining member 44 to maintain the first drive rack 29 in engagement with the first output pinion gear 28. The engagement of these complementary surfaces maintains the distance between the ends of the deformable link 30 helping to prevent the first drive rack 29 disengaging from the first output pinion gear 28. The deformation of the deformable link 30 allows the first torsion tube 11 to rotate about the pivot axis A. Depending on the direction of rotation of the first torsion tube 11 (determined by the direction of the force applied to the squab assembly 2), one of the first and second prongs 52, 53 disposed on the pivot bracket 51 engages the spindle 54 and inhibits further rotation of the first torsion tube 11. The first and second prongs 52, 53 thereby provide functional end stops for limiting angular rotation of the squab assembly 2.
The first and second guard members 55, 56 define end stops for the squab assembly 2. The first guard member 55 has upper and lower first flanges 55U, 55L arranged to cooperate with the deformable link 30 and/or the drive rack 29 and/or the constraining member 44 to limit angular rotation of the squab assembly 2. Similarly, the second guard member 56 has upper and lower second flanges 56U, 56L arranged to cooperate with the outer edges of the first and second prongs 52, 53 to limit angular rotation of the squab assembly 2. It will be appreciated that the angular arrangement of the first and second prongs 52, 53 may define positive and negative lockout angles for the squab assembly 2. The lockout angle may be adjusted to provide a range of +ve and −ve rotation with maximum total angle determining the freedom of the deformable link 30 and/or the drive rack 29 between the upper and lower first flanges 55U, 55L.
The deformable link 30 provides progressive deformation under load. After deformation of the deformable link 30 by a predetermined amount, the upper and lower flanges 55U, 55L, 56U, 56L function as stop members and transmit energy into the remainder of the structure. The deformable link 30 helps to maintain geometrical integrity in strategic locations within the vehicle seat assembly (for example the seat squab for neck and spinal support) whilst allowing controlled deformation in less sensitive areas (for example the chassis 7 under the seat cushion pan and/or in the region proximal to the first and second torsion tubes 11, 18).
The arrangement of the chassis 7 described herein is such that its width may be adjusted with relative ease. Thus, the vehicle seat assembly 1 may be reconfigured to accommodate different widths of seats. For example, the vehicle seat assembly 1 may be reconfigured to suit different sizes of the seat pan.
It will be appreciated that the deformable link 30 may be configured to undergo deformation under a predetermined load. Moreover, the spacing of the first and second prongs 52, 53 may be adjusted to determine the range of rotational movement of the squab assembly 2. It will be appreciated that the pivot bracket 51 may have more than two prongs.
The deformation of the deformable link 30 provides a visual indication that an excessive load has been applied to the vehicle seat assembly 1. This may not otherwise be readily determined by inspection of the squab assembly 2, particularly if the squab assembly 2 incorporates a composite structure. The deformable link 30 may be replaced, for example as a service item. In certain embodiments, the deformable link 30 may be configured such that deformation indicates that the squab assembly 2 should be inspected and/or replaced. The deformable link 30 may optionally comprise one or more mark, for example a series of timing marks, for providing a visual indication that deformation has occurred and optionally also the extent of any such deformation. The one or more mark may be viewed to facilitate determining that deformation had occurred, for example to highlight when the deformable link 30 has undergone only slight deformation. The one or more mark may be visually inspected by removing the first guard member 56. In certain embodiments, the one or more mark may be visible through an aperture (not shown) in the first guard member 56.
The concentric arrangement of the first and second torsion tubes 11, 18 provides packaging advantages and allows the diameter of the torsion tubes 11, 18 to be increased compared to prior art arrangements. At least in certain embodiments, this may provide improved stability and load distribution of the vehicle seat assembly 1, for example in the mounting of the first and second beams 12, 13.
It will be appreciated that various changes and modifications may be made to the vehicle seat assembly 1 described herein without departing from the scope of the present application. Alternatives to the deformable link include clamped friction plates configured to slide relative to each other; or twisting of a lever around a friction pivot.
It will be appreciated also that the deformable link 30 described herein may be incorporated into other control functions in the vehicle seat assembly 1, For example, the deformable link may be disposed between the second torsion tube 18 and the second output pinion gear 34. A second drive rack may be associated with the second output pinion gear 34. In this arrangement, the deformable link would be integrated into the height rise function.
Number | Date | Country | Kind |
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1515698.7 | Sep 2015 | GB | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2016/070058 | 8/25/2016 | WO | 00 |