WO2009135684A2

WO2009135684A2 - Lumbar support mounting device

Info

Publication number: WO2009135684A2
Application number: PCT/EP2009/003300
Authority: WO
Inventors: Wayne Andrew Harris; Andrew James Elliot
Original assignee: Kongsberg Automotive Asa
Priority date: 2008-05-08
Filing date: 2009-05-08
Publication date: 2009-11-12
Also published as: WO2009135684A3

Abstract

A lumbar support mounting device for a vehicle seat includes a support member (14) in the form of a frame or panel having a width dimension between edges at opposite sides and a length dimension between upper and lower ends which are large relative to the depth of the frame or panel perpendicular to those dimensions. At or adjacent to its upper end, the support member is adapted for connection to an upper transverse cross member of the frame of the seat backrest. Intermediate of the upper and lower ends of the support member, the device includes a respective wing structure (16) which extends outwardly from each side edge. Intermediate of the wing structures, the device further includes a holding structure which is adapted to hold each wing structure in a substantially constant spacing and orientation relative to the other wing structure.

Description

LUMBAR SUPPORT MOUNTING DEVICE

FIELD OF THE INVENTION

[0001] This invention relates to a lumbar support mounting device for a vehicle seat. The device has particular application to, but is not limited to use with, a seat having an active head restraint which provides for protection of an occupant of the seat in the event of a rear end collision to the occupant's vehicle.

BACKGROUND OF THE INVENTION

[0002] In all fluid systems, there is a need to guard against damage associated with pressure surges. Typically, a pressure surge is generated when there is a change in the rate of flow of fluid in a closed conduit. The surge pressure can be dangerously high if the change in the rate of fluid flow in the conduit is too great. In many applications, such as pipelines and storage or loading/unloading terminals, there is a need to protect equipment and personnel from the potential damages that such pressure surges create.

[0003] There have been many proposals for an active head restraint system for a vehicle seat which is adjustable in the event of a rear end collision to better protect the head of an occupant against whiplash. The head restraint of the system may be moveable as a whole relative to a seat backrest on which it is mounted, to a forward or a forward and upward position closer to the occupant's head. Alternatively, the head restraint may have a first portion moveable forwardly to such forward position with respect to a second portion fixed relative to the seat backrest. In either arrangement, the movement frequently results from the system including an actuator, positioned to be acted on by a rearward force from the body of the occupant in the event of a rear end collision, and a force transmitter by which the force is transferred from the actuator to the headrest The actuator may, for example, be positioned at or below the occupant's back, such as the lumbar region to be contacted by the occupant's back or posterior. The actuator may include a moveable part, such as a plate or lever, connected to a lower section of a frame of the seat backrest via a linkage system, with the linkage system operable to transfer to the force transmitter the force applied to the moveable part The force transmitter may for example comprise a Bowden cable.

SUMMARY OF THE INVENTION

[0004] The present invention seeks to provide a lumbar support mounting device, and also a lumbar support system including the device and a lumbar support, for use in a vehicle seat. In at least some forms, the device may be integrated with an active head restraint system for the seat.

[0005] According to the invention there is provided a lumbar support mounting device for a vehicle seat, the device including a support member in the form of a frame or panel having a width dimension between edges at opposite sides and a length dimension between upper and lower ends which are large relative to the depth of the frame or panel perpendicular to those dimensions. At or adjacent to its upper end, the support member is adapted for connection to an upper transverse cross member of the frame of the seat backrest. Intermediate of the upper and lower ends of the support member, the device includes a respective wing structure which extends outwardly from each side edge. Also, intermediate of the wing structures, the device includes a holding structure which is adapted to hold each wing structure in a substantially constant spacing and orientation relative to the other wing structure.

[0006] The wing structures are adapted to enable a lumbar support band to be secured across the width of the support member, with each end of the band connected to a respective one of the wing structures. With the support member connected, at or adjacent to its upper end, to an upper transverse member of the frame of the seat backrest, the support member supports the wing structures and, hence, a lumbar support band secured on wing structures across the support member, at a suitable height enabling the lumbar support band to provide adjustable support in the lumbar region of an occupant seated on the seat.

[0007] The support member may be in the form of a stiff frame, such as of wire or rod formed to a required shape. Each wing structure also may be in the form of a stiff frame, such as of wire or rod formed to a required shape. The support member may be formed separately from the wing structures, with the wing structures secured to the support member. Thus, for example, where made of metal wire or rod, the wing structures may be secured to the support member by welding, or as is preferred, by the wing structures and the support member being clamped together.

[0008] Where the support member is in the form of a stiff frame, the holding structure may comprise at least one stiff member which is connected to each of opposite side portions of the support member adjacent to the wing structures. Additionally, or alternatively, the holding structure may comprise at least one stiff member which is connected to each of the wing structures. In each case, the support member has a stiffness enabling it to hold the side portions of the support member and the wing structures at a substantially constant spacing, and to retain the wing structures at a substantially constant mutual orientation. Thus, the wing structures are able to hold opposite ends of a lumbar support band, secured across the support member, at a substantially constant spacing, such as by each end of the lumbar support band being connected to an end of a respective wing structure which is remote from the other wing structure.

[0009] Where the support member is in the form of a stiff frame, it may be of stiff wire or rod formed to a U-shape configuration. Where the support member is formed to that configuration, it preferably has first and second elongate portions each defining a respective one of opposite sides of the support member, and a third elongate portion joining the first and second portions and defining a lower end of the support member. End portions of the first and second portions may be configured to define an upper end of the support member by which the mounting device is connectable to a transverse member of a seat backrest frame. In one convenient arrangement, the free end portion of each of the first and second portions of the support member has the form of a crank bend, enabling it to be inserted through a respective opening or aperture in the transverse member of the seat backrest frame and thereby retained to suspend the support member below the member or portion of the frame of the seat backrest.

[0010] As an alternative to being in the form of a stiff frame, the support member may be flexible and comprise a frame, lattice or sheet. Where the mounting device has a flexible support member, the wing structures and the holding structure are rigid or stiff, with each wing structure connected to a respective end of the holding structure and with the support member connected to the holding structure at least at intervals across the width of the support member between its opposite sides to the holding structure. With the upper end of the support member connected to an upper member or portion of a seat backrest frame, the wing structures and the holding structures are suspended below the upper member or portion of the frame. The rigid ity or stiffness of the wing structures and the holding structure preferably are such as to hold the wing structures at a substantially constant distance apart and at a substantially constant mutual orientation.

[0011] In a further alternative, the support member may be rigid and comprise a lattice or sheet. In that alternative, the holding structure may consist of a strengthened band of the support member which extends across the width of the support member between the opposite sides of the latter. The strengthened band may be provided by thickening of the support member, or by the support member being strengthened by being formed to define ribs extending between the opposite sides.

[0012] As indicated, a respective wing structure extends outwardly from each side edge of the support member. The wing structures may extend in a plane substantially parallel to the side edges. However, it is preferred that the wing structures are inclined with respect to that plane such that, relative to an in use orientation of the mounting device, the wing structures extend outwardly and forwardly from the support member. The wing structures may be inclined at an angle of from about 30° to 50° to the plane, such as from about 35° to 45°.

[0013] As indicated, the length and width dimensions of the support member are large relative to its depth. The length dimension may be from about 2 to 3 times greater than the width dimension. The support member may have a width dimension which is from about 25 to 50 times, such as from about 30 to 40 times, the thickness dimension. The width dimension may vary along the length of the support member. The support member may have a minimum width dimension which is from about 25 to about 40 times, such as about 30 to 35 times, the thickness dimension. The support member may have a maximum width dimension which is about 35 to 50 times, such as about 40 to 45 times, the thickness dimension.

[0014] A lumbar support for use in a lumbar support system according to the invention may be in the form of an elongate lumbar support band which extends longitudinally between the wing structures of the mounting device of the system and which has an effective length capable of variation so as to vary the rearward curvature of the band when the lumbar support is adjusted in use. The lumbar support may be of a type which, in another context, extends longitudinally between the sides of the seat backrest frame. Lumbar supports of that type are illustrated in US patents 5685606 and 5716098 both to Lance, US patents 5769490 and 6254186 both to Falzon and US 6918634 to Elliot, the disclosure of each of which is hereby incorporated herein by reference.

[0015] Variation in the rearward curvature of the lumbar support band may be enabled by a spacing between first and second elongate portions of a support member in the form of a stiff frame. In that event, the holding structure to hold each wing structure also may be rearwardly curved. Where the support member has the form of a flexible frame, lattice or sheet, or a rigid lattice or sheet, the support member itself may be held so as to be rearwardly curved, or formed with rearward curvature, with the holding structure also so curved. In each case, the curvature of the holding structure, or of the support member, is in planes substantially perpendicular to the opposite sides of the support member. However, while the support member and holding structure may have such rearward curvature, the variation in rearward curvature of the lumbar support band may be enabled partly or wholly by the extent to which the wing structures extend outwardly and the extent to which they are forwardly inclined.

[0016] The upper end of the support member may be adapted for connection to an upper transverse cross member of the seat backrest frame in a manner providing a pivot connection. Where provided, the pivot connection enables the lumbar support mounting device to pivot in the fore and aft directions relative to the backrest frame. This pivoting enables the mounting device to facilitate the transference of a force from the occupant of the seat to an actuator. Thus, in the event of a rear end collision, the mounting device can enable the actuator to act through a force transmitter to adjust an active head restraint to better protect the head of the occupant against whiplash.

[0017] As an alternative to the upper end of the support member having a pivot connection with the backrest frame, the connection may be non-pivotal. In that alternative, the support member may be able to flex such that, in the event of a rear end collision, a force from the seat occupant is able to be transferred to the actuator by the support member flexing in response to the force. Again, a force transmitter can be operated to adjust the head restraint for protection against whiplash.

[0018] At or towards its lower end, the support member of the lumbar support mounting device may define a bar or plate comprising a moveable part of an actuator. The bar or plate may be connected to a lower section of the seat backrest frame via a linkage system. The arrangement may be such that, in the event of a rear end collision, the bar or plate moves with rearward pivoting of the lumbar support mounting device due to a force from the seat occupant. The bar or plate thereby causes the linkage system to adjust and thereby transmit the force through a force transmitter to adjust the active heat restraint to protect against whiplash.

BRIEF DESCRIPTION OF THE FIGURES

[0019] In order that the invention may more readily be understood, reference is directed to the accompanying drawings, in which:

[0020] Figure 1 is a front elevation of a lumbar support mounting device in combination with a lumbar support system;

[0021] Figure 2 is a side elevation of the combination of Figure 1 ;

[0022] Figure 3 is a front perspective view of the combination of Figures 1 and 2, with some components omitted;

[0023] Figures 4 and 5 are a front elevation and a side elevation, respectively, of a first component of the mounting device of Figures 1 and 2; [0024] Figures 6 to 8 are front and side elevations and a top plan view of a second component of the device of Figures 1 and 2;

[0025] Figures 9 and 10 are a perspective and front elevational view of a third component of the device of Figures 1 and 2;

[0026] Figure 11 is a sectional view taken on line A-A of Figure 10;

[0027] Figures 12 to 14 are front elevation and side elevations, and a top plan view, respectively of a fourth component of the device of Figures 1 and 2;

[0028] Figure 15 is a sectional view taken on line B-B of Figure 13;

[0029] Figures 16 to 19 show front and side elevations and top and bottom plan views, respectively of the second, third and fourth components secured in assembly with the first component;

[0030] Figures 20 to 22 show a rear perspective view, a front elevation, and a rear elevation of a lumbar support band;

[0031] Figure 23 is a sectional view taken on line C-C of Figure 21;

[0032] Figure 24 shows on an enlarged scale the encircled section S of Figure 23;

[0033] Figure 25 shows the sectional view taken on line D-D of Figure 22; and

[0034] Figure 26 schematically illustrates a seat backrest frame, showing an arrangement for positioning an active head restraint by a lumbar support mounting device according to the invention.

[0035] With reference to Figures 1 and 2, there is shown, in combination, a lumbar support mounting device 10 and a lumbar support system 12. The device 10 also is shown in Figure 3, although part of the lumbar support system 12 have been omitted from Figure 3 for ease of illustration.

DETAILED DESCRIPTION

[0036] The lumbar support mounting device 10 includes a first component comprising the support member 14 shown in Figures 4 and 5. Device 10 also includes a second component comprising a wing structure assembly 16 shown in Figures 6 to 8. Additionally, device 10 has a third component in the form of a first mounting bracket 18 shown in Figures 9 and 10, and a fourth component shown in Figures 12 to 14 in the form of a second mounting bracket 20.

[0037] The support member 14 is shown in Figures 4 and 5. In the form shown, member 14 is made from steel wire or rod, such as of hard drawn ASTM 227 class 1 steel of about 5 mm diameter, preferably provided with a powder dip coating. The wire or rod is bent to provide member 14 with a U-shape, as viewed in the front elevation of Figure 4. The member 14 has first and second elongate portions 21 and 22 at opposite sides of member 14, and a third portion 23 which joins portions 21 and 22 to define a lower end of member 14. While of U-shape in front elevation, portions 21, 22 and 23 are not in a common plane. Rather, a short distance above portion 23, each of portions 21 and 22 is bent to provide a rearwardly set-back region 21a and 22a. Also, above the regions 21a and 22a, the portions 21 and 22 are bent through a number of acute angles such that the upper end of each of the portions 21 and 22 is located forwardly with respect to the regions 21a and 22a and, to a lesser extent, with respect to the portion 23.

[0038] In addition to the above-detailed fore and aft bending of member 14, the portions 21 and 22 exhibit lateral bending. As a consequence, the lateral spacing between upper longitudinal regions 21 b and 22b of portions 21 and 22, is greater than the lateral spacing of portions 21 and 22 below regions 21b and 22b, while regions 21b and 22b are slightly forwardly positioned. Also, the free ends of regions 21b and 22b define the upper end of member 14 by which member 14 is connectable to an upper transverse member of the frame (not shown) of a seat backrest (not shown). To enable such connection, the free end of each region 21b and 22b is provided with a crank bend 21c and 22c. The arrangement is such that, with member 14 horizontally disposed, the free ends of regions 21b and 22b can be inserted through apertures in the backrest frame transverse member to engage the crank bends 21c and 22c in the apertures. The member 14 then can be rotated to its in use vertical disposition in which it is suspended from the cross member of the frame by the crank bends being engaged in the apertures. The suspension of member 14 is such that the mounting device 10, with the lumbar support system 12 mounted thereon, is able to be securely suspended in a required positioning with respect to the seat backrest frame.

[0039] The wing structure assembly 16 is shown in Figures 6 to 8.

In the form shown, the assembly 16 is made from steel wire or rod, such as about 4 mm diameter hard drawn ASTM class 1 steel. The assembly

16 has a laterally elongate, rectangular form as viewed in the front elevation of Figure 6, with the free ends of the wire or rod closely juxtaposed in a lower, central location. However, as seen most clearly in the top plan view of Figure 8, end portions are bent from a central portion 24 to provide laterally and forward Iy extending wing structures 25 and 26. The assembly 16 is secured to support member 14, across the set-back regions 21a and 22a of portions 21 and 22 of member 14. The securement is by means of first mounting bracket 18, as detailed more fully in relation to Figures 16 to 19, with wing structures 25 and 26 projecting laterally and forwardly beyond regions 21a and 22a, respectively.

[0040] The bracket 18, as shown in Figures 9 to 11 , is of elongate rectangular form and is produced from steel plate, such as cold rolled low carbon steel of about 1 mm thick. Bracket 18 is formed from sheet material and has an elongate, rectangular body 28 strengthened by a longitudinal rib 28a from the ends of which short diagonal ribs 28b diverge. Spaced along the each longer side of body 28, bracket 18 has a respective series of upturned tabs 30, while a similar respective series of tabs 31 is spaced along each end of body 28.

[0041] The bracket 20, as shown in Figures 12 to 15, is formed from an elongate, rectangular strip of steel which may be similar to that used for bracket 18. Bracket 20 has a long body 32 and, from each end of body 32, a respective end portion 33, 34 is turned forwardly. Spaced a short distance from each of end portions 33, 34, the body 32 has a respective opening 35, 36 and, projecting rearwardly of body 32 from each opening, a respective tab 37, 38. The bracket 20 is strengthened by a marginal strip at each longitudinal edge being rolled to form a raised strengthening bead 40.

[0042] Figures 16 to 19 show the assembly of support member 14, the wing structure assembly 16, the first bracket 18 and the second bracket 20. In the case of each of these components other than bracket 20, wing structure assembly 16 is clamped to the body 28 of bracket 18, while the body 28 of bracket 18 is clamped to support member 14. The arrangement is such that wing structures 25 and 26 project laterally and forwardly with respect to member 14, specifically from the respective sides 21 and 22 of member 14 at a lower part of the set-back regions 21 a and 22a.

[0043] The spacing between the sides 21 and 22 of member 14, at the set-back regions 21a and 22a, is such that member 14 is neatly receivable between the respective series of tabs 31 at the opposite ends of body 28 of bracket 18. With the member 14 so received, so body 28 extends across the lower extent of the set-back regions 21a, 22a, the series tabs 31 are rolled around and grip the respective one of portions 21 and 22. Similarly, the spacing between the upper and lower runs 24a and 24b of the central portion 24 of assembly 16 is such that portion 24 is neatly receivable between the upper and lower series of tabs 30 of bracket 18. With portion 24 so received, the tabs 30 then are rolled over so that each series of tabs 30 extends around and grips the respective one of runs 24a and 24b. As assembly 16 extends across the front of member 14 and bracket 20 is to approach member 14 from the rear, bracket 20 first is secured by tabs 31 to member 14 in the arrangement shown, after which assembly 16 is presented from the front and secured by tabs 30. However, other assembly procedures are permitted if bracket 20 is presented so that its tabs 30 and 31 project rearwardly from body 28.

[0044] The spacing between tabs 37 and 38 of bracket 20 is substantially the same as that between the two series of tabs 31 of bracket 18. Thus, an upper extent of member 14 is able to be neatly received between tabs 37 and 38 and bracket 20 then is able to be secured in relation to member 14 by each of tabs 37 and 38 being rolled around and grip a respective one of portions 21 and 22. As shown, bracket 20 as secured in relation to member 14 is spaced above bracket 18 and assembly 16, a short distance below upper regions 21b and 22b of portions 21 and 22.

[0045] The bracket 18 serves to secure assembly 16 in relation to member 14. However, bracket 18 also functions as a holding structure which secures the wing structures 25 and 26 in a substantially constant spacing and orientation relative to each other. Also, as with bracket 20, bracket 18 holds portions 21 and 22 of member 14 at a substantially constant spacing.

[0046] The lumbar support system 12 shown in Figures 1 and 2 has a lumbar support band 42, two motorised actuators 43 and 44, and a pair of Bowden cables 45 and 46 connecting each of actuators 43 and 44 through the band 42.

[0047] As can be appreciated from Figures 1 and 2, in combination with Figures 20 to 25, the lumbar support band 42 has an elongate central zone 47, a respective strap 48 extending beyond each end of zone 47, and a respective connector 49 at the outer end of each strap 48. The connectors 49 each have a main body 49a connected to or integral with the respective strap 48, and a cover 49b which is connected to the body 49a by integral hinges 49c therebetween. The body defines a groove 49d which extends laterally with respect to band 42. The groove 49d is of a size enabling it to neatly receive the upright end section 25a or 26a (see Figures 6 and 7) of a respective one of wing structures 25 and 26. With each of sections 25a and 26a received in the groove 49d of a respective connector body 49a, the covers 49b are pivotable to lay over the groove and secure a connector 49 in relation to each wing structure 25, 26. Each cover 49b may be secured to its connector body 49a by a releasable snap-fit interengagement therebetween, or by a fastener extending therethrough. The connectors thus secure band 42 across the mounting device 10.

[0048] The length of band 42 between connectors 49 is such that, with band 42 secured across device 10 with each connector 49 captive on a respective one of sections 25a and 26a of wing structures 25 and 26, the band is able to exhibit rearward curvature. That is, that length of band 42 is greater than the spacing between sections 25a and 26a of wing structures 25 and 26. Also, the length of the central zone 47 of band 42 is able to be varied to vary the extent of rearward curvature of the band overall. That is, the effective length of band 42 is able to be varied and, with variation in that effective length, the degree of lumbar support the system 12 provides to a seat occupant is able to be varied.

[0049] Variation in the effective length of band 42 is enabled by the form of the central zone 47 of band 42, and drive imparted to zone 47 by actuators 43 and 44 via the Bowden cables 45 and 46. The zone 47 is made up of a series of five elongate elements 50a, 50b, 50c, 5Od and 5Oe which extend transversely of the longitudinal extent of band 42. The first and last elements 50a and 5Oe are connected to the inner end of a respective strap 48, while successive pairs of elements 50a to 5Oe are spaced from each other by respective pairs of bridging elements 52 with which the elements are integral. The bridging elements 52 are resilient and they can flex to enable zone 47, and hence band 42, to increase or decrease in length to vary the rearward curvature of band 42.

[0050] Adjustment of band 42 is achieved by operation of actuators 43 and 44, each powered by a respective electric motor 43a and 44a. For this, each cable 45 and 46 has a first tubular sleeve 45a and 46a which extends between actuator 43 and the one end of zone 47 of band 42, and a second tubular sleeve 45b and 46b which extends between actuator 44 and the other end of zone 47 of band 42. Each cable 45 and 46 also has a wire core 45c and 46c which extends between the mechanism of one of actuators 43, 44, through the first and second tubular sleeves to the mechanism of the actuators 43, 44. At the one end of zone 47, each of the first sleeves 45a and 46a has its end captured in a respective one of abutments 54 defined in opposite ends of elongate elements 5Oe₁ while the other ends of sleeves 45a and 46a are captured with the mechanism or housing of actuator 43. Similarly, each of the second sleeves 45b, 46b has its end captured in a respective one of abutments 55 defined in opposite ends of elongate element 50a, with their other ends captured with the mechanism or housing of actuator 44. Between the sleeves 45a and 46a, the wire core 45c is held by formations at the back of elements 50b, 50c and 5Od through which the wire cores are longitudinally slidable. [0051] The way in which the rearward curvature of band 42 can be adjusted depends on the arrangement within and mode of operation of actuators 43 and 44. This will be understood by those skilled in the art. Operation may for example be as disclosed, for example, in the above- mentioned US patent 5769490 to Falzon, the disclosure of which is incorporated herein by reference. Alternative forms of adjustable lumbar supports suitable for use with the mounting device 10 of the invention also are disclosed in US 5769490, as well as in the further US patents identified earlier herein and also incorporated herein by reference.

[0052] With the mounting device 10 connected at the upper end of its member 14 to a transverse cross member of a seat backrest frame, the combination of the mounting device 10 and a lumbar support system 12 is suspended below that cross member. The combination 10, 12 therefore is able to pivot or flex in the fore and aft direction. As a consequence, rearward pivoting or flexing of the member 14 of the mounting device 10 in the event of a rear end collision can be used to adjust an active head restraint so as to minimise the risk of an occupant of the seat suffering a whiplash injury.

[0053] Figure 26 illustrates an arrangement by which the support member 14 of the mounting device 10 is connected to an upper transverse cross-member 60 of a seat backrest frame 62. Only member 14 and frame 62 is shown in Figure 26. However, it will be apparent from Figure 26 how the combination of the support mounting device 10 and the lumbar support system 12 mounted on device 10 are connected to frame 62. The cross-member 60 has two laterally spaced apertures (not apparent in Figure 26) through each of which the free end of a respective region 21 b and 22b of member 14 is inserted. For this, the member 14 is presented and manoeuvred to locate the crank bends 21c and 22c in the apertures in cross-member 60, so as to releasably lock member 14 in relation to the backrest frame 62. Thus, with member 14 locked in this way, the laterally extending lumbar support band 42 of system 12 is vertically suspended.

[0054] The lower extent of the backrest frame 62 has an actuator 64 secured thereto. Actuator 64 includes a plate 66 secured at each end to a respective one of opposite side members 68 of frame 62, just above a lower transverse member 69 which joins the lower ends of members 68. In front of plate _,66, actuator 64 includes a linkage system 70 having a series of links 70a hinged together in a W-configuration, as viewed from above. The system 70 has a respective rearwardly projecting pin 71 at each end which locates in a guideway 67 which extends transversely along a centre region of plate 66. The pins 71 hold system 70 captive against plate 68, but allow system 70 to expand from or contract to the rest position illustrated, in a concertina fashion enabled by pins 71 sliding along guideway 67. In expanding or contracting, the system 70 is able to transmit a force applied to actuator 64 to an active head restraint system 72 via a force transmitter which, in the arrangement of Figure 26, comprises a Bowden cable 74. The link 70a at one end of system 70 is connected to the wire core 74a of the cable 74, while the other end of the wire core 74a is connected to an operating mechanism 76 of the active head restraint system 72. The cable 74 also includes an outer sleeve 74b in which core 74a is slidable, with sleeve 74b longitudinally fixed by abutments (not shown). When the system 70 is expanded by an applied force, the wire core 74a of cable 74 is pushed or pulled, depending on whether it passes to system 70 direct or via a pulley, thereby to advance at least a front portion of head rest 73 of system 72 to a forward position in which the front portion can better protect a seat occupant against whiplash.

[0055] The force for expanding system 70 is intended to be applied by the posterior or lower back region of the seat occupant as a consequence of a rear end collision to the vehicle in which the occupant is seated. For this, the portion 23 of support member 14 is adjustably connected to the front of system 70. As shown, portion 23 extends through connectors 70b attached to system 70 at forward ridges 70c defined at the hinged connection between each outermost link 70a and the next adjacent link 70a. The arrangement is such that as the applied force from the seat occupant acts such as through the lumbar support system 12 to cause rearward flexing or pivoting of member 14, the portion 23 of member 14 transfers the force to system 70, causing system 70 to expand. The connectors 70b are able to slide along portion 23 as required to enable system 70 to expand and contract.

[0056] In the event that rearward curvature of band 42 of system 12 has been adjusted to minimise or remove lumbar support for the seat occupant, the force from a seat occupant for expanding system 70 may act directly on mounting device 10. That is, member 14 of device 10 may be caused to flex or pivot rearwardly substantially without the force acting through system 12. The force may, for example, act directly on portion 23 of member 14.

[0057] Application of a force which expands system 70 may necessitate the force acting against a biasing means (not shown) of actuator 64 which, when the force is removed, contracts the system 70 to the rest position. Alternatively, system 70 may be returned to the rest position solely under the action of device 10 and system 12 returning to their normal positions and thereby drawing connectors 70b forwardly.

[0058] Finally, it is to be understood that various alterations, modifications and/or additions may be introduced into the constructions and arrangements of parts previously described without departing from the spirit or ambit of the invention.

Claims

We claim:

1. A lumbar support mounting device for a vehicle seat, wherein the device includes a support member in the form of a frame or panel having a width dimension between edges at opposite sides and a length dimension between upper and lower ends which are large relative to the depth of the frame or panel perpendicular to those dimensions; at or adjacent to its upper end, the support member is adapted for connection to an upper transverse cross member of the frame of the seat backrest; intermediate of the upper and lower ends of the support member, the device includes a respective wing structure which extends outwardly from each side edge; and wherein, intermediate of the wing structures, the device further includes a holding structure which is adapted to hold each wing structure in a substantially constant spacing and orientation relative to the other wing structure.

2. A device according to claim 1 , wherein the wing structures are adapted to enable a lumbar support band to be secured across the width of the support member, with each end of the band connected to a respective one of the wing structures.

3. A device according to claim 1 or claim 2, wherein the support member is in the form of a stiff frame, such as of wire or rod formed to a required shape.

4. A device according to claim 3, wherein each wing structure is in the form of a stiff frame, such as of wire or rod formed to a required shape.

5. A device according to any one of claims 1 to 4, wherein the support member is formed separately from the wing structures, with the wing structures secured to the support member by welding, or by the wing structures and the support member being clamped together.

6. A device according to claim 1 , wherein the support member is in the form of a stiff frame, and the holding structure comprises at least one stiff member which is connected to each of opposite side portions of the support member adjacent to the wing structures.

7. A- device according to claim 6. wherein the holding structure comprises at least one stiff member which is connected to each of the wing structures.

8. A device according to claim 6 or claim 7, wherein the support member has a stiffness enabling it to hold the side portions of the support member and the wing structures at a substantially constant spacing, and to retain the wing structures at a substantially constant mutual orientation.

9. A device according to claim 1 or any one of claims 6 to 8, wherein the support member is in the form of a stiff frame of stiff wire or rod formed to a U-shape configuration and has first and second elongate portions each defining a respective one of opposite sides of the support member, and a third elongate portion joining the first and second portions and defining a lower end of the support member.

10. A device according to claim 9, wherein end portions of the first and second portions are configured to define an upper end of the support member by which the mounting device is connectable to a transverse member of a seat backrest frame.

11. A device according to claim 10, wherein the free end portion of each of the first and second portions of the support member has the form of a crank bend, enabling it to be inserted through a respective opening or aperture in the transverse member of the seat backrest frame and thereby retained to suspend the support member below the member or portion of the frame of the seat backrest.

12. A device according to claim 1, wherein the support member comprises a frame, lattice or sheet, the wing structures and the holding structure are rigid or stiff, with each wing structure connected to a respective end of the holding structure and the support member connected to the holding structure at least at intervals across the width of the support member between its opposite sides to the holding structure, and the rigidity or stiffness of the wing structures and the holding structure preferably is such as to hold the wing structures at a substantially constant distance apart and at a substantially constant mutual orientation.

13. A device according to claim 1 , wherein the support member is rigid and comprises a lattice or sheet, and the holding structure consists of a strengthened band of the support member which extends across the width of the support member between the opposite sides of the latter.

14. A device according to claim 13, wherein the strengthened band is provided by thickening of the support member, or by the support member being strengthened by being formed to define ribs extending between the opposite sides.

15. A device according to any one of claims 1 to 14, wherein the wing structures extend in a plane substantially parallel to the side edges.

16. A device according to any one of claims 1 to 14, wherein the wing structures are inclined with respect to a plane substantially parallel to the side edges such that, relative to an in use orientation of the mounting device, the wing structures extend outwardly and forwardly from the support member.

17. A device according to claim 16, wherein the wing structures are inclined at an angle of from about 30° to 50° to the plane, such as from about 35° to 45°.

18. A device according to claim 18, wherein the length dimension of the support member is from about 2 to 3 times greater than the width dimension of the support member.

19. A device according to claim 18, wherein the width dimension is from about 25 to 50 times, such as from about 30 to 40 times, the thickness dimension.

20. A device according to claim 18, wherein the width dimension varies along the length of the support member, and wherein the support member has a minimum width dimension which is from about 25 to about 40 times, such as about 30 to 35 times, the thickness dimension, and has a maximum width dimension which is about 35 to 50 times, such as about 40 to 45 times, the thickness dimension.

21. A lumbar support system, including a lumbar support mounting device according to any one of claims 1 to 20 and an elongate lumbar support band which extends longitudinally between the wing structures of the mounting device of the system and which has an effective length capable of variation so as to vary the rearward curvature of the band when the lumbar support is adjusted in use.

22. A device according to any one of claims 1 to 21, wherein at or towards the lower end of the support member, the support member defines a bar or plate comprising, or connectable to, a moveable part of an actuator.

23. A device according to claim 22, wherein the moveable part is connectable to a lower section of the seat backrest frame via a linkage system.

24. A device according to claim 23, wherein the bar or plate is moveable with rearward pivoting or flexing of the lumbar support due to a force from a seat occupant, whereby the bar or plate causes the linkage system to adjust and thereby transmit the force through a force transmitter to adjust an active head restraint.