WO1999041144A1

WO1999041144A1 - Foot fixing for a vehicle seat assembly

Info

Publication number: WO1999041144A1
Application number: PCT/GB1999/000442
Authority: WO
Inventors: James Thompson; Stephen Philips; Andrew Lawler
Original assignee: Reynard Aviation Limited
Priority date: 1998-02-13
Filing date: 1999-02-12
Publication date: 1999-08-19
Also published as: GB2334882A; GB9803122D0; AU2533699A; GB2334882B; GB9914981D0; GB2337454A

Abstract

A foot fixing for a vehicle seat, said fixing comprising track engaging means (14) for engaging a seat track of a vehicle, seat engaging means (26) that can be fixedly secured to a seat, and deformable blade (22) interposed said track engaging means and said seat engaging means, which deformable blade is adapted to absorb energy by deforming in the event of the fixing being subjected to pitching due to an abnormal loading, such as in the event of an impact.

Description

FOOT FIXING FOR A VEHICLE SEAT ASSEMBLY

The present invention relates to a foot fixing for a vehicle seat assembly, and has particular reference to seat assemblies for use on an aircraft. The present invention also embraces a novel seat assembly, particularly a passenger seat assembly.

Seats on aircraft and other passenger vehicles are commonly fixedly secured to the infrastructure of the vehicle by means of seat tracks . Such seat tracks are conventionally arranged in pairs and extend substantially longitudinally of the vehicle. The seats themselves are typically provided as integral units, each unit including two or more individual seats . Each seat unit is secured to one of the pairs of seat tracks.

A problem with this arrangement is that the spacing of the seat tracks within each pair varies from aircraft to aircraft . Furthermore, the seat tracks rarely extend parallel to one another, but are usually canted along the length of the aircraft. In particular, those skilled in the art will appreciate that where the seat tracks extend into the nose-cone of an aircraft (e.g. on a Boeing 747 aircraft) the seat tracks may be curved, so as to run generally parallel to the side walls of the aircraft.

Thus, individual seat units must be designed and manufactured to fit not only the specific aircraft on which they are intended to be used, but also a given seat unit must be tailored to fit its intended, specific location on the aircraft. As a result, there is a proliferation in the number of different kinds of seat units that must be manufactured for a given aircraft, and the problem is compounded when different marques of aircraft are taken into account.

A conventional aircraft seat unit comprises a plurality of front and rear legs that are positioned to mate with the seat tracks provided on the aircraft to which the seat unit is to be fitted. Typically, each seat track engages one front leg and one rear leg of each seat unit, and a structural member extends between the lower ends of the front and rear legs in parallel to the seat track to give rigidity and strength to the seat unit. In addition, a second structural member extends transversely of the seat tracks at a position spaced above the seat tracks, below the seat pans of the seats included in the seat unit. Each rear leg of a seat unit is fixedly secured to its respective seat track by means of a foot block. Said foot block equipped with a plurality (usually two or three) of depending studs that are shaped to engage in the seat track. A conventional seat track comprises an extruded channel having two opposing, longitudinally extending flanges that define a narrow slot therebetween. Said opposing flanges are cut-out at 2.54cm (1 inch) intervals to form circular openings into which the studs may be entered. After inserting the studs through the circular openings, the foot block is displaced by half an inch in the longitudinal direction so as to engage the studs in the channel. The foot block further comprises a shear plunger which can be inserted through one of the circular openings in the seat track once the foot block is in position and then tightened down onto the seat track to resist longitudinal movement of the foot block relative to the track. A foot block of this kind is a relatively bulky assembly and, as it comprises a number of separate parts, is relatively expensive to manufacture.

Each front leg of the seat unit is secured to its respective seat track by a front leg fitting comprising a single, depending stud which is inserted through one of the circular openings in the track channel in a similar fashion to the studs of the foot block assembly.

As those skilled in the art will be aware, the front leg fitting does not include a shear plunger, because owing to manufacturing tolerances and the repair and replacement of sections of the seat tracks, the circular openings in the channel of the seat track and the depending studs of the front leg fittings often do not align properly once the foot block assembly on the rear leg is in position.

Seat assemblies for use on passenger vehicles such, for example, as aircraft are required to meet exacting safety standards. In particular, the seat assemblies are required to absorb a substantial portion of the energy from an impact such as occurs in the event of a collision, so as to divert the full force of the impact away from a passenger using the seat. To this end, the joint between the rear legs of each seat unit and the corresponding foot blocks have a degree of built-in mechanical flexibility so as to absorb small pitching movements of the seat tracks relative to one another. Typically, the joint between a rear leg and a foot block is in a form of a clevis incorporating a spherical bushing. An object of the present invention is to provide an improved foot fixing for a vehicle seat.

In particular, it is an object of the present invention to provide a foot fixing for a vehicle seat which will allow the seat to be secured to the seat tracks of any make of aircraft and at any desired position of the aircraft.

A further object of the present invention is to provide a low-level foot fixing which does not constitute a trip hazard.

A further object of the present invention is to provide a foot fixing for a vehicle seat that is simpler and more economical to manufacture than prior art foot fixing.

Another object of the present invention is to provide an improved seat assembly for use on vehicles, particularly aircraft.

In particular, an object of the present invention is to provide a seat assembly which can be fitted to any aircraft and at any position on the aircraft. A further object of the present invention is to provide a seat assembly which can be fixedly secured to a pair of seat tracks , both forwardly and rearwardly of the seat assembly by means of shear plungers .

According to one aspect of the present invention therefore there is provided a foot fixing for a vehicle seat, said foot fixing comprising track engaging means for engaging a seat track of a vehicle, seat engaging means that can be fixedly secured to a seat, and a deformable blade interposed said track engaging means and said seat engaging means, which deformable blade is adapted to absorb energy by deforming in the event of the fixing being subjected pitching due to an abnormal loading, such as in the event of an impact.

Said deformable blade forms a connection between the track engaging means and the seat engaging means and is constructed to absorb energy when the vehicle seat is subjected to an impact, so as to divert energy away from a passenger using the seat. In particular, the deformable blade is capable of absorbing pitching deformation of the seat tracks relative to the seat. The foot fixing of the present invention has the advantage that it can be made as a compact unit or assembly. In particular, the deformable blade can be made relatively short, and thus the spacing of the seat from the seat tracks can be reduced as compared with prior art foot fixings. By way of example, the height of the blade in the fitted position may be in the range 2 to 10mm, preferably about 4mm.

Preferably, the deformable blade is oriented substantially parallel to the longitudinal axis of the seat track.

Said track engaging means may comprise a shear load bearing means and a tensile load bearing means. In particular, said tensile load bearing means may comprise one or more studs of the kind known in the art that are arranged to engage in the seat track. Specifically, each stud may comprise an enlarged base portion that is shaped to be received in the seat track and an upstanding neck portion that is adapted to extend through an upper opening formed in the seat track.

Preferably , the deformable blade is formed integrally with the stud(s) , and the up-standing neck portion of the stud(s) and the deformable blade are formed as a continuous piece. Preferably the seat engaging means are formed integrally with the deformable blade, and in some embodiments, the seat engaging means, deformable blade and stud(s) may be forged or cast as a single piece to form a foot block component .

It will be appreciated by those skilled in the art that the deformable blade must be made from a non-brittle material. The blade should be capable of plastic or elastic deformation in the event of excessive loading between the seat and seat track. It is envisaged that any suitable metal or thermoplastic material may be used, but aircraft standard steel reference no. S143 is used.

Said shear load bearing means may comprise a plunger component that is pivoted on the foot block component, said plunger component comprising track gripping means that is selectively movable between a gripping position and a released position. Said plunger component is designed to provide a jacking movement to facilitate anti-rattle. To this end, said plunger component may include a shaped cam portion being shaped such that as the plunger component is pivoted towards the fitted position, the cam portion exerts a downward force on the track which urges or "jacks" the footblock component upwards into engagement with the flanges of the track, so as to jam the footblock component in the track, so as to prevent rattling of the footblock component. Said plunger component may further comprise a stud to locate the plunger component in the seat track. Said gripping means may comprise a rotatable latch that is shaped to engage the track in the gripping position so as to prevent longitudinal movement of the fixing in the track. Conveniently, means may be provided for allowing a visual indication when the track gripping means is in the gripping position. For instance, the latch may be mounted on the plunger component by means of a screw, and visible lines may be provided on the screw head and plunger component, such that the two lines are lined up with one another when the latch is in the gripping position.

Preferably, the plunger component is shaped so that in the fitted position, the plunger component lies flat across the top of the seat track.

Said plunger component may be made from the same or a different structural material as the foot block component . Said seat engaging means may comprise any suitable means for fastening the foot block component to a seat. Preferably however the seat engaging means comprises a slider that is shaped to engage in a channel formed in the seat or a part connected thereto. Said slider may be oriented with respect to the track engaging means, such that the slider is arranged to slide in a direction transverse the longitudinal axis of the seat tract, preferably substantially orthogonally thereto.

According to another aspect of the present invention there is provided a seat assembly for a vehicle, said assembly comprising a seat, a cross-member that can be fixedly secured to a lower end of the seat and fixing means for fixing said cross-member to a plurality of seat tracks provided in the vehicle. Preferably, the seat assembly is for use on an aircraft.

In a particularly preferred aspect of the present invention, said fixing means comprise one or more foot fixings in accordance with the present invention.

Typically, said seat will comprise a plurality of rear legs, and said cross-member may be adapted to be secured to the lower end of each rear leg. Said seat may comprise a plurality of front legs, and similarly, a cross-member may be adapted to be secured to the lower ends of the front legs .

Preferably, the seat is equipped with both front and rear legs, and two cross-members are provided. A first cross-member may be securable to the rear legs, and a second cross-member may be securable to the front legs.

The underside of the cross-member may be formed within an elongate channel that is adapted to engage said fixing means. It will be understood by those skilled in the art that the number of foot fixings used to secure the cross- member to the seat tracks will depend on the number of seat tracks present. Thus, where, as is usual, a pair of seat tracks are provided then said cross-member will be secured to the seat tracks by two foot fixing.

Said cross-member may be shaped such that the upperside of the member defines a shallow, convex curve in cross- section. The cross-member that may thus have a low-level configuration so that it does not present a significant trip hazard.

Said cross-member(s) may be made from any suitable structural material, although extruded aluminium section is preferred from the point of view of strength and lightness .

Said seat may comprise a fixed portion that is adapted to be secured to the cross-member(s) and the movable portion which movable portion comprises a back-rest, seat pan and leg-rest. Said movable portion may be movable between a fully reclined position and an upright position. Said fixed portion may define a recess that is disposed below the back-rest and seat pan in the upright position, which recess is capable of receiving the leg-rest of a seat positioned behind the seat in question. The fixed part of each seat may be provided with two spaced rear legs that are positioned respectively on opposing sides of the seat, to either side of the recess. An advantage of the present invention is that the legs of the seat do not have to be positioned over the seat tracks on an aircraft, but may be secured to the cross-member(s) at any convenient locations, the cross-member itself then being secured directly to the seat tracks .

In an especially preferred aspect of the present invention the seat is a seat of the kind disclosed in United Kingdom patent application no. 9706650.0, the contents of which are incorporated herein by reference.

Following is a description by way of example only with reference to the accompanying drawings of embodiments of the present invention.

In the drawings :-

Figure 1 is a side view, partly in cross-section, of a foot fixing in accordance with the present invention.

Figure 2 is a bottom view of the foot fixing of figure 1.

Figure 3 is a front view of the foot fixing in the direction of the arrow labelled III in Figure 1.

Figure 4 is an end view, partly in cross-section, of a seat assembly in accordance with the present invention.

Figure 5 is a side view, partly in cross-section, of the seat assembly of figure 4.

Figure 6 is an isometric view of a frame for a seat assembly of the kind shown in figures 4 and 5.

Figure 7 is an isometric view from above and to one side which shows how the foot fixing of figures 1 to 3 can be assembled with a seat track and a seat assembly for fixing the seat assembly to the track.

With reference to figures 1, 2 and 3 a foot fixing (10) comprises a foot block component ( 12 ) and a plunger component (42). Said foot block component (12) is made as a single piece from a steel alloy that is suitable for use in aircraft constructions . Said alloy should be non- brittle and capable of deformation when subjected to high loads . In the embodiments shown in the drawings , steel alloy reference S143 is employed.

Said foot block component ( 12 ) comprises a track engaging portion (14) that is generally frustoconical in side view and has a flat bottom surface (16) at its widest part. Said flat bottom surface (16) is generally dumb bell shaped, defining two, generally circular stud portions (18), the centres of which are spaced apart from one another on a longitudinal axis indicated by the dashed line (20) in figure 2. The narrower end of the track engaging portion (14) extends away from the flat bottom surface (16) and meets a narrow, waisted portion (22) that has the form of an elongate blade as shown clearly in Figure 3. Said blade is oriented substantially parallel to said longitudinal axis (20). The length of the blade portion along the longitudinal axis, is about 25mm, and its height, perpendicular to the longitudinal axis is about 5mm. The thickness of the blade, orthogonal to the longitudinal axis (20) and in parallel to the plane of the flat bottom surface (16), is about 15mm at the narrowest part.

Remote from the track portion (14), the blade portion (22) is joined to a circular disc portion (24), which disc portion (24) carries thereon a slider portion (26) having a T-shaped section in a plane orthogonal to the flat bottom surface (16) of the track engaging portion (14), as shown in figure 1.

In plan view, said slider portion (26) is generally oval in outline as shown in figure 2, and the major axis of the oval shape is oriented substantially orthogonally to the longitudinal axis (20). Said slider portion (26) is drilled either side of the blade portion (22) to provide two spaced open bores (28), each of which open bores (28) accommodates a fixing screw (30) for fixing the slider portion (28) to a vehicle seat in a manner as described hereinafter.

The centres of the two generally circular studs (18) are spaced apart by about 2.54cm (1 inch), so that the studs can be inserted through the coin shaped slots formed in an aircraft seat track of the kind well known to those skilled in the art.

The track engaging portion (14) of the foot block component (12) further comprises a protruding lug (32) that extends on said longitudinal axis (20). Said lug portion (32) is drilled at (34) to accommodate a pin (36) of a clevis connector (38) of said plunger component (42). The joint between the clevis connector (38) and the lug (32) allows the plunger component (42) to be pivoted on the pin (36) with respect to the foot block component between a released position as shown in dashed lines in figure 1 and a fitted position as shown in solid lines. As can be seen from Figure 1, said clevis connector (38) is formed with a integral protrusion (39) that forms a cam. In the fitted position of the plunger component (42), the protrusion (39) extends downwardly below the bottom surface (16) of the foot block component (12) . Said protrusion is shaped such that as the plunger component (42) is pivoted to the fitted position, the protrusion (39) engages the seat track and by a camming action pushes downwards on the track, which in turn urges or "jacks" the foot block component (12) upwards into engagement with the flanges forming the slot in the track. This causes the footblock component (12) to be jammed firmly in the track, thus preventing rattle of the components in the track after installation.

Said clevis connector (38) is formed on one end of an elongate rib portion (44) that extends from the foot block component (12) on said longitudinal axis (20). Said rib portion (44) carries a depending stud (46) of circular cross-section and a generally flat, rectangular web portion (48). The centre of the depending stud (46) is spaced from the centres of the stud portions (18) on the foot block component (14) by n x 12.7mm, where n is an odd number. Juxtaposed the stud (46), the rib portion (44) is drilled at (50) to accommodate a screw (52). The hole (50) is countersunk to accommodate the head of the screw (52), which screw protrudes from the rib portion (44) and carries at its other end a key (54) that is keyed onto the stem of the screw (50). In order to fix a seat assembly to a seat track, the slider portion (26) of the foot block component (12) is secured to a seat assembly (76,90,96) as described below. With reference to figure 7, the track engaging portion (14) is entered into the seat track (100), with the plunger component (42) in the released position, such that the two studs (18) enter two neighbouring coin slots on the track. The foot block component (12) (and attached seat assembly) is then displaced along the track by 12.7mm (ø"), so that the studs (18) are engaged in the seat track. The plunger component (42) is then pivoted about the clevis connection, so that the stud (46) enters another coin slot on the track, and the web portion (48) lies flush across the top of the track. The screw (52) is then turned, so that the key (54) engages the inner side walls of the track to prevent longitudinal movement of the foot fixing (10) with respect to the seat track.

In the event of an excessive load being applied between the seat assembly and the seat track (e.g. in the event of a collision) the blade portion (22) is capable of deforming to absorb some of the energy of the impact, so as to direct energy away from the body of a passenger using the seat. With reference to figures 4 and 5, a seat assembly (6) comprises two seats (62) arranged side-by-side. Each seat comprises a fixed frame (70) and a movable part (80). Figure 5 shows an isometric view of the seat assembly (60) with the movable parts (80) of the two seats removed for clarity.

Each of said frames (70) comprises two opposing side walls (72), a back wall (74) and two spaced rear legs (76), each of which rear legs (76) is secured to respective one of the side walls (72). As can be seen from figure 6, the back wall (74) of each seat (62) has a sinuous configuration in side-view extending generally downwardly and forwardly from an upper extremity of the seat (62) above the rear legs (76) to a forward position at the bottom of the seat. Said back wall (74) defines, with the rear legs (76), a foot well space at (81). At the front of each seat, each of the side walls (72) carries a short, stub front leg (78).

The movable part (80) of each seat (62) comprises a backrest portion (82), a seat pan portion (84) and a leg-rest portion (86). The movable part (80) can be moved progressively between two positions - an upright position and a fully reclined position. The position of the movable part (80) of one of the seats (62) is shown in both of these positions in figure 5. When fitted to a vehicle, such as an aircraft, a plurality of seat assemblies (60) of this kind can be positioned one behind another, so that in use the leg-rest portion (86) of one seat in the fully reclined position extends into the foot well (81) of the seat in front. Passenger seats of this kind are disclosed in more detail in pending United Kingdom patent application no. 9706650.0, the contents of which are incorporated herein by reference.

As shown most clearly in figure 6, the lower ends of the rear legs (76) of the two seats (62) of the seat assembly (60) are fixedly secured to an elongate cross bar (90). Similarly, the stub front legs (78) of the two seats (62) are attached to a second cross bar (92). Each of said cross bars (90,92) is cut from a length of extruded, pressed aluminium. Each of said cross bars (90,92) has a substantially flat underside (94) which is formed with an elongate channel (96), which channel extends into the body of the cross bar. Said channel (96) is generally T-shaped in cross-section and is shaped to accommodate the slider portions (26) of one or more foot fixings of the kind described above, although it is envisaged that other kinds of fixings may be used without departing from the scope of the present invention.

For each of the cross bars (90,92), the required number of foot fixings (10) are slid into the channels (96) depending on the number seat tracks to which the seat assembly is to be anchored. As shown in figure 4, it is usually the case that each seat assembly is to be secured to two spaced seat tracks (100). As can further be seen from figure 4, each of the seat tracks (100) is positioned more or less centrally with respect to the foot well (80) of a respective one of the seats (62). Thus, two foot fixings (10) are engaged with each of the cross bars (90,92), and these foot fixings (10) slid along the channels (96) in the cross bars (90,92) until the foot fixings are positioned in alignment with the seat tracks (100). The foot fixings can then be fastened to the cross bars (90,92) by means of the two screws (30) in each fixing (10). Each fixing (10) is then secured to a respective seat track (100) in the manner described above.

It will be appreciated by those skilled in the art that the seat assembly of the present invention can thus be secured to two or more seat tracks in any aircraft (or vehicle), and at any location on that aircraft, because the position of the foot fixings (10) can be adjusted according to the spacing of the seat tracks (100). Moreover, the assembly of the cross bars (90,92) with the foot fixings (10) provides a very low level anchorage between the seat tracks and the seat assembly (60) which does not constitute a significant trip hazard, and moreover allows the leg-rest portion (86) of a seat located behind the seat assembly in question to be extended into the foot well (81) so as to optimise the use of space on the vehicle.

A further advantage of the foot fixing (10) and seat assembly (60) of the present invention is that a positive engagement can be provided at both the front and rear ends of the seat by means of a shear plunger which resists longitudinal movement of the seat assembly along the seat tracks. The inherent flexibility of the legs (76,78) allows the spacing between the two cross bars (90,92) to be adjusted slightly, so that the plungers of the foot fixings secured to both cross bars (90,92) can be properly aligned with coin slots in the seat tracks . It will be noted by those skilled in the art that the seat assembly of the present invention does not include any stiffening frame components between the front and rear legs (76,78) in juxtaposition with the vehicle floor. The recess formed by the two cross bars (90,92) can be filled in by means of a convenient, planar infill piece (98) as shown in figure 6.

Claims

1. A foot fixing for a vehicle seat, said foot fixing comprising track engaging means for engaging a seat track of a vehicle, seat engaging means that can be fixedly secured to a seat, and a deformable blade interposed said track engaging means and said seat engaging means, which deformable blade is adapted to absorb energy by deforming in the event of the fixing being subjected to pitching due to an abnormal loading, such as in the event in an impact.

2. A foot fixing as claimed in claim 1 wherein said deformable blade is capable of absorbing pitching deformation of the seat tracks relative to the seat.

3. A foot fixing as claimed in claim 1 or claim 2 wherein the height of the blade in the fitted position is in the range 2 to 10mm.

4. A foot fixing as claimed in claim 1, claim 2 or claim 3 wherein, when fitted, the deformable blade is oriented substantially parallel to the longitudinal axis of the seat track.

5. A foot fixing as claimed in any preceding claim wherein said track engaging means comprises a shear load bearing means and a tensile load bearing means.

6. A foot fixing as claimed in claim 5 wherein said tensile load bearing means comprises one or more studs that are arranged to engage in the seat track.

7. A foot fixing as claimed in claim 6 wherein each stud comprises an enlarged base portion that is shaped to be received in the seat track and an upstanding neck portion that is adapted to extend through an upper opening formed in the seat track.

8. A foot fixing as claimed in claim 7 wherein the deformable blade is formed integrally with the stud(s) and the upstanding neck portion of the stud(s) and the deformable blade are formed as a continuous piece.

9. A foot fixing as claimed in any preceding claim wherein the seat engaging means are formed integrally with the deformable blade.

10. A foot fixing as claimed in claim 6, claim 7 or claim 8 wherein said seat engaging means, deformable blade and stud(s) are forged or cast as a single piece to form a foot block component .

11. A foot fixing as claimed in claim 10 wherein said shear load bearing means comprises a plunger component that is pivoted on the foot block component, said plunger component comprising track gripping means that are selectively movable between a gripping position and a released position.

12. A foot fixing as claimed in claim 11 wherein said plunger component includes a shaped cam portion that is shaped such that as the plunger component is pivoted towards the fitted position, the cam portion exerts a downward force on the track which urges or "jacks" the foot block component upwards into engagement with the flanges of the seat track, so as to jam the foot block component in the track.

13. A foot fixing as claimed in claim 11 or claim 12 wherein said plunger component further comprises a stud to locate the plunger component in the seat track.

14. A foot fixing as claimed in claim 11, claim 12 or claim 13 wherein said gripping means comprises a rotatable latch that is shaped to engage the track in the gripping position, so as to prevent longitudinal movement of the fixing in the track.

15. A foot fixing as claimed in any claims 11 to 14 wherein the plunger component is shaped so that in the fitted position, the plunger component lies flat across the top of the seat track.

16. A foot fixing as claimed in any preceding claim wherein the seat engaging means comprises a slider that is adapted to engage in a channel formed in the seat or a part connected thereto .

17. A foot fixing as claimed in claim 16 wherein the slider is oriented with respect to the track engaging means, such that the slider is arranged to slide in the direction transverse the longitudinal axis of the seat track.

18. A seat assembly for a vehicle, said assembly comprising a seat, a cross-member that can be fixedly secured to a lower end of the seat and fixing means for fixing said cross-member to a plurality of seat tracks provided in the vehicle.

19. A seat assembly as claimed in claim 18 wherein said fixing means comprises one or more foot fixings as claimed in any of claims 1 to 17.

20. A seat assembly as claimed in claim 18 or claim 19 wherein said seat comprises a plurality of rear legs and said cross-member is adapted to be secured to the lower end of each rear leg.

21. A seat assembly as claimed in any of claims 18 to

20, wherein the seat comprises a plurality of front legs and a cross-member is adapted to be secured to the lower ends of the front leg.

22. A seat assembly as claimed in any of claims 18 to

21, wherein the seat is equipped with both front and rear legs, and two cross-members are provided.

23. A seat assembly as claimed in any of claims 18 to 22, wherein said cross-member is formed with an elongate channel that is adapted to engage said fixing means .

24. A seat assembly as claimed in any of claims 18 to 23 wherein the cross-member is adapted to be secured to two substantially parallel seat tracks by two foot fixings .

25. A seat assembly as claimed in any of claims 18 to 24, wherein the cross-member is shaped such that an upper side of the member has a shallow, convex surface.

26. A seat assembly as claimed in any of claims 18 to 25, wherein the seat comprises a fixed portion that is adapted to be secured to the cross-member(s) and a movable portion which movable portion comprises a back rest, a seat pan and a leg rest.

27. A seat assembly as claimed in claim 26 wherein said movable portion is movable between a fully reclined position and an upright position.

28. A seat assembly as claimed in claim 27, wherein the fixed portion defines a recess that is disposed below the back rest and seat pan in the upright position, which recess is capable of receiving the leg rest of the seat positioned behind the first seat.

29. A seat assembly as claimed in claim 28, wherein the fixed part of each seat is provided with two spaced rear legs that are positioned respectively on opposing sides of the seat, to either side of the recess .

30. A foot fixing substantially as hereinbefore described with reference to and as illustrated in figures 1 to 3 of the accompanying drawings.

31. A seat assembly substantially as hereinbefore described with reference to and as illustrated in figures 4 to 6 of the accompanying drawings .