GB2619723A

GB2619723A - Passenger seat assembly for an aircraft

Info

Publication number: GB2619723A
Application number: GB2208658.1A
Authority: GB
Inventors: Hacker Mark; Jansenns Sam; Bowker James
Original assignee: Unum Aircraft Seating Ltd
Current assignee: Unum Aircraft Seating Ltd
Priority date: 2022-06-13
Filing date: 2022-06-13
Publication date: 2023-12-20
Also published as: WO2023242544A1; GB202208658D0

Abstract

A passenger seat assembly 100 for an aircraft is configurable between a seating configuration and a flat-bed configuration comprising, a base 101 for connection to the floor of the aircraft; a seat carriage 103 comprising a curved rail; a backrest 109 attached to the seat carriage 103; a lumbar support 107 pivotally attached to the seat carriage 103 at a first pivot; and a seat pan 105 pivotally attached to the seat carriage at a second pivot. The curved rail of the seat carriage is moveable relative to the base 101, moving the seat carriage 103 along an arc defined by the curvature of the curved rail 111. The seat pan 105 and the lumbar support 107 are arranged such that articulation of the seat pan 105 about the second pivot causes articulation of the lumbar support 107 about the first pivot between a lumbar-supporting configuration wherein the lumbar support 107 and the backrest 109 are angled with respect to one another; and a flat configuration where the backrest 109 and lumbar support 107 are substantially coplanar. There is also claimed an arrangement where the curved rail comprises a toothed rack and the base comprises a pinion or toothed wheel.

Description

Passenger seat assembly for an aircraft

Field of the Invention

The present invention concerns passenger seat assemblies. More particularly, but not exclusively, this invention concerns a passenger seat assembly having a seat carriage with a curved rail. The invention also concerns a seating arrangement in the cabin of an aircraft.

Background of the Invention

Different seating classes exist in commercial aviation, such as economy class, premium economy, first class and business class. Business class seats tend to occupy a greater amount of space per passenger than economy or premium economy seats. In all of the classes, and especially in business class, it tends to be desirable to increase passenger comfort, especially without negatively impacting on the space occupied by a seat unit.

Various possible layouts exist in business class seating. These include a herringbone layout, which comprises columns of adjacent seat assemblies, all orientated at an angle to the longitudinal axis of the aircraft cabin. Outboard facing herringbone arrangements and inboard facing herringbone arrangements are known.

Outboard facing herringbone arrangements are those in which the seats accommodate a passenger such that in the seating position the passenger faces towards the closest wall (side) of the aircraft (i.e. they look outwardly from the aircraft). Herringbone layouts tend to enable relatively high-density arrangements.

Business class seat assemblies are typically configurable between a seating configuration and a sleeping configuration in which a planar lie-flat sleeping surface is provided. Some business class seat assemblies are also able to adopt an intermediate configuration in which there is a recline of the seat's backrest. Having multiple different configurations of the seat is desirable, but it is also desirable for the seat assembly to consistently provide a high level of comfort in of all these different configurations. It is desirable to provide these features without negatively impacting on other design-critical features such as the space occupancy, weight, complexity and/or serviceability of the seat assembly.

DE102012108351A1 shows an example of a seat unit which is configurable between a seating configuration, an intermediate configuration and a bed configuration. The seat assembly in DE102012108351A1 comprises a curved rail for effecting the movement between these configurations The present invention seeks to provide an improved seat assembly.

Summary of the Invention

According to a first aspect of the invention, there is provided a seating assembly for an aircraft, the seat assembly being configurable between a seating configuration and a flat-bed configuration. The seat assembly comprises; a base for connection to the floor of the aircraft; a seat carriage comprising a curved rail; a backrest attached to the seat carriage; a lumbar support pivotally attached to the seat carriage at a first pivot; and a seat pan pivotally attached to the seat carriage at a second pivot. The seat carriage may be supported by the base. The curved rail of the seat carriage may be moveable relative to the base, preferably thereby moving the seat carriage along an arc defined by the curvature of the curved rail. The seat pan and the lumbar support may be arranged such that articulation of the seat pan about the second pivot causes articulation of the lumbar support about the first pivot between a lumbar-supporting configuration and a flat configuration. In the lumbar-supporting configuration the lumbar support and the backrest may be angled with respect to one another. In the flat configuration the backrest and lumbar support are preferably substantially coplanar.

This aspect of the present invention recognises that by linking the configuration of the lumbar support with the position of the seat pan, an arrangement may be provided in which there is lumbar support for a passenger when the seat assembly is in a seating configuration (typically created by the formation of an uneven or convex surface), but when the seating assembly is in a flat-bed configuration, there is no such uneven or convex surface (because the lumbar support is co-planar with the backrest and seat pan).

It will be appreciated that unless otherwise stated, references to relative orientations of the seat pan, lumber support and backrest are made with reference to their respective support surfaces (e.g. the surface formed by the cushion for contacting the passenger, or a datum thereof).

The seat pan and the lumbar support are arranged such that articulation of the seat pan about the second pivot causes articulation of the lumbar support about the first pivot between the lumbar-supporting configuration and the flat configuration. The articulation of the lumbar support is preferably indirectly actuated by actuation of the seat pan. In the some embodiments, the seat assembly may not necessarily, therefore, require a lumbar support actuation assembly and/or actuator. This may enable a relatively simple and/or lightweight arrangement In the lumbar-supporting configuration the lumbar support preferably forms a lumbar supporting surface for a passenger. The surface may be formed by the backrest and lumbar support forming an angle with one another. In the lumbar-supporting configuration, the backrest and the lumbar support may form a convex support surface. In the lumbar-supporting configuration, the backrest and the lumbar support may be non-co-planar.

The seat assembly may be configured such that when the seat assembly is in the seating configuration, the lumbar support is in the lumbar-supporting configuration. The seat assembly may be configured such that when the seat assembly is in the flat-bed configuration, the lumbar support is in the flat configuration.

The lumbar support may have a first end, proximate to the backrest. The lumbar support may have a second end, proximate to the seat pan. The lumbar pivot may be located at the first end. The second end of the lumbar support may occupy a position further towards the seat carriage when in the lumbar-supporting configuration than when in the flat configuration. Such an arrangement may, for example, result in the formation of a relatively convex surface in the lumbar-supporting configuration, compared to the planar surface in the flat configuration.

The backrest may be fixedly attached to the seat carriage. The backrest is preferably fixedly attached to the seat carriage such that movement of the seat carriage results in corresponding movement of the backrest. In some embodiments, there is preferably no relative movement between the backrest and the seat carriage during movement between the seating configuration and the flat-bed configuration.

Such an arrangement has been found to be beneficial because the backrest may follow the path (for example the arcuate path) of the curved rail.

The passenger seat assembly may comprise a headrest. The headrest may be fixedly attached to the seat carriage. In some embodiments the headrest may be co- -4 -planar with the backrest but in other embodiments, the headrest may be non-coplanar with the backrest. In the latter case, a pillow may be provided on top of the head rest when the seat assembly is in flat-bed configuration.

The seat assembly is preferably arranged such that when the seat pan is co-planar with the backrest, the lumbar support is in the flat configuration. Such an arrangement may thereby ensure that by articulating the seat pan to a position that is co-planar with the backrest, an entire planar sleeping surface is provided (the lumbar support being positioned between the backrest and the seat pan).

The seat pan and lumbar support may be connected by a guide and a follower.

One of the seat pan or the lumbar support may be associated with the guide and the other of the lumbar support or the seat pan may be associated with the follower arranged to be moveable within the guide. In preferred embodiments, the seat pan may comprise the guide and the lumbar support may comprise the follower. Embodiments comprising a guide and follower arrangement have been found to be effective in transferring movement of one component (e.g. the seat pan) into movement of another component (e.g. the lumbar support). The guide may form a substantially constant radius curve.

The seat pan may comprise an extension, such as an arm, in which a guide groove is located. The lumbar support may comprise an extension, such as an arm, having a follower extending therefrom and arranged to move within the guide groove.

The guide is preferably shaped to provide movement of the lumbar support between the lumbar-supporting configuration and the flat configuration The base may comprise a carriage actuation assembly. The carriage actuation assembly may be configured to move the carriage relative to the base. The carriage actuation assembly may comprises a rack, a pinion and an actuator. The rack may be curved and the curved rail of the carriage may comprises the curved rack. The base may comprise the pinion. Rotation of the pinion may be effected by the actuator. The rack and the pinion may intermesh such that rotation of the pinion results in movement of the carriage along an arcuate path defined by the curved rail. A rack and pinion arrangement has been found to be especially effective, particularly in enabling movement of the backrest to a wide variety of positions within the movement range defined by the curved rail.

The seat assembly may comprises a seat pan actuator for effecting movement of the seat pan. The seat pan actuator may comprise an actuator, for example a linear -5 -actuator. The actuator may be connected at one end to the seat carriage and at its opposing end to the seat pan. The seat assembly may be arranged such that retraction of the seat pan actuator causes (via pivoting of the seat pan) the lumbar support to adopt the flat configuration. The seat assembly may be arranged such that extension of the seat pan actuator causes (via pivoting of the seat pan) the lumbar support to adopt the lumbar-supporting configuration.

The seat pan movement relative to the seat carriage, and the curved rail movement relative to the base, are preferably independent movements. Those independent movement are preferably controlled by the seat pan actuator and the carriage actuation assembly respectively. Having independent movement of the seat pan and the backrest has also been found to readily enable a large variety of seating positions to be adopted by the passenger, thereby ensuring a passenger can seek a configuration of the backrest and the seat pan orientation that best suit them. In some embodiments of the invention, the arrangement of the seat pan on the seat carriage may beneficially reduce the power/torque required for the seat pan to adopt certain positions. The carriage actuation assembly may be configured to provide a greater force/power to affect actuation than the linear actuator.

The seat assembly may be configurable into an intermediate configuration. In the intermediate configuration, the curved rail may be moved part-way between its relative positions in the seating configuration and the flat-bed configuration. In the intermediate configuration the backrest may be at a reclined angle (relative to the seating configuration). In the intermediate configuration the root end of the seat pan (the end closest to the carriage and/or lumbar support) may be lowered relative to the front end of the seat pan (i.e, the free edge at the front of the seat pan). The orientation of the seat pan in the intermediate configuration may be such that the hips of a passenger occupying the seat, are lowered relative to their upper legs. The intermediate position may therefore facilitate a 'zero-g' or lazy-Z' position, which is recognised as being an especially comfortable position for a passenger. Embodiments of the invention comprising the seat carriage having a curved rail have been found to be especially beneficial in enabling this configuration. This is because the curved rail enables movement of the backrest and seat pan in a way that lowers the passenger's hip position as the seat assembly moves from the seating configuration towards the flat-bed configuration. -6 -

The seat assembly may be arranged such that in the intermediate position, the lumbar support may be in the lumbar supporting configuration. Such an arrangement is especially beneficial because it provides lumbar support to the passenger in this intermediate position (whilst still enabling the lumbar support to adopt the flat configuration, for example when the seat assembly is in the flat-bed configuration).

The seat assembly may further comprises a leg rest. The leg rest may be pivotally attached to the seat pan. The leg rest may be rotatable relative to the seat pan between a stowed position (for example in which the leg rest is at an angle to the seat pan, such as downwards or below the seat pan), to a bed position, in which the leg rest is substantially co-planar with the seat pan. The seat assembly may be arranged such that the leg rest is in the bed position when the seat assembly is in the flat-bed configuration. In the bed position the leg rest may form a continuous surface with the seat pan. The leg rest may be moveable by means of an actuator, for example a linear actuator, attached at one end to the seat pan and at the other end to the leg rest.

According to a second aspect of the invention there is also provided a passenger seat assembly for an aircraft, wherein the passenger seat assembly comprises a base and a carriage. The base may comprise a toothed wheel, and the seat carriage comprising a curved toothed rack, the curved toothed rack and the toothed wheel being arranged to interface such that rotation of the toothed wheel moves the curved rack along an arcuate path relative to the base. The arcuate path is preferably defined by the curvature of the rack. The seat assembly may further comprise a backrest, a lumbar support and seat pan attached to the curved rail. The seat assembly may be arranged to be configurable between: an upright position in which the backrest, lumbar support and seat pan are positioned in a seating position to provide an upright seating surface; a zero-u reclined position in which the backrest, lumbar support and seat pan are positioned in a reclined position such that a rearmost portion of the seat pan is lowered relative to a foremost portion of the seat pan; and a flat-bed configuration in which the backrest, lumbar support and the seat pan are substantially coplanar. In the upright position and the zero-g position, the backrest and the lumbar support may maintain substantially similar relative positions. In these positions, the backrest and the lumbar support may form a convex surface (for example they may be non-co-planar). The seat assembly may comprise an actuator for rotating the pinion. -7 -

According to a further aspect, there is provided a kit of parts for forming a seating assembly, the kit of parts comprising: a base, preferably comprising a pinion; and a seat carriage comprising a curved rail, preferably having a curved toothed rack; and a backrest, a lumbar support and a seat pan, the backrest, a lumbar support and a seat pan being configurable to attach to the seat carriage.

According to another aspect, there is provided a seating arrangement in the cabin of a passenger aircraft, the arrangement comprising a column of the seat assemblies described herein. The seating assemblies may be arranged in a herringbone formation in which consecutive seat assemblies in the column are orientation at an acute angle to the longitudinal axis of the aircraft cabin. The seat assemblies may be adjacent a sidewall of the aircraft and face outwardly towards the sidewall. Embodiments of the invention have been found to be especially beneficial in this type of layout.

It will of course be appreciated that features described in relation to one aspect of the present invention may be incorporated into other aspects of the present invention. For example, the seat assembly of the second aspect may incorporate any of the features described with reference to the seat assembly of the first aspect and vice versa.

Description of the Drawings

Embodiments of the present invention will now be described by way of example only with reference to the accompanying schematic drawings of which: Figure 1 shows a side view of a seat assembly according to a first embodiment of the invention; and Figure 2 shows a side view of the seat assembly according to the first embodiment of the invention; and Figure 3 shows a side view of the seat assembly according to the first embodiment of the invention; and Figures 4a to 4h show side views of a part of seat assembly according to the first embodiment of the invention; Figure 5 shows a perspective view of a base of the seat assembly according to a first embodiment of the invention; -8 -Figure 6 shows a front view of a base of the seat assembly according to the first embodiment of the invention; Figure 7 shows a perspective view of a seat carriage, backrest and headrest of the seat assembly according to the first embodiment of the invention; Figure 8 shows a rear view of the seat carriage, backrest and headrest of the seat assembly according to the first embodiment of the invention; Figure 9 shows a close-up rear view of the seat carriage, backrest and headrest of the seat assembly according to the first embodiment of the invention; Figure 10 shows a close-up perspective view of the base and seat carriage of the seat assembly according to the first embodiment of the invention; Figure 11 shows a perspective view of the seat carriage of the seat assembly according to the first embodiment of the invention; Figure 12 shows a side view of the seat carriage of the seat assembly according to the first embodiment of the invention; Figure 13 shows a front view of the seat carriage of the seat assembly according to the first embodiment of the invention; Figure 14 shows a side view of a seat pan of the seat assembly according to the first embodiment of the invention; Figure 15 shows a perspective view of the seat pan of the seat assembly according to the first embodiment of the invention; Figure 16 shows a side view of a lumbar support of the seat assembly according to the first embodiment of the invention, Figure 17 shows a perspective view of the lumbar support of the seat assembly according to the first embodiment of the invention; Figure 18 shows a perspective view of the lumbar support and the seat pan of the seat assembly according to the first embodiment of the invention; Figure 19 shows a perspective view of the lumbar support, a seat pan actuator and the seat pan of the seat assembly according to the first embodiment of the invention; Figure 20 shows a rear view of part of the seat assembly according to the first embodiment of the invention; Figure 21 shows a perspective view of part of the seat assembly according to the first embodiment of the invention; -9 -Figure 22 shows a side view of part of the seat assembly according to the first embodiment of the invention; Figure 23 shows a rear perspective view of part of the seat assembly according to the first embodiment of the invention; Figure 24 shows a layout of passenger accommodations (LOPA) according to an embodiment of the invention; Figure 25 shows a layout of passenger accommodations (LOPA) according to a second embodiment of the invention; Figure 26 shows a perspective view of a seat assembly according to a third embodiment of the invention; Figure 27 shows a perspective view of a seat assembly according to a third embodiment of the invention; Figure 28 shows a perspective view of a seat assembly according to a third embodiment of the invention; Figures 29a to 29h show side views of a part of seat assembly according to the fourth embodiment of the invention; Figure 30 shows a perspective view of the lumbar support and the seat pan of the seat assembly according to the fourth embodiment of the invention; Figure 31 shows a perspective view of the lumbar support, a seat pan actuator and the seat pan of the seat assembly according to the fourth embodiment of the invention; and Figure 32 shows a rear view of part of the seat assembly according to the fourth embodiment of the invention;

Detailed Description

In a first embodiment of the invention, there is provided a seat assembly for a business class seat unit. The seat assembly has a seat carriage which has a curved rail at one (rear) edge. The curved rail is moveable through a base, which has an actuator for moving the curved rail of the seat carriage through an arc movement. The other face (the front face, i.e. the passenger facing side) of the seat carriage has a backrest fixedly attached thereto, and a lumbar support and a seat pan pivotally attached thereto. When the seat carriage is moved through the arc movement, the seat assembly -10 -moves between an upright configuration suitable for sitting in, one or more intermediate configurations suitable for lounging in, and a lie-flat (i.e. flat-bed) configuration suitable for sleeping in. The seat pan is actuated separately to the actuation of the curved rail by the actuator in the base. The seat pan actuator moves the seat pan about its pivotal connection to the seat carriage such that the seat pan moves between a configuration suitable for sitting, to a configuration where it is substantially coplanar with the backrest (suitable for sleeping). The seat pan is linked (connected via a linkage) to the lumbar support, and the linkage which connects them is arranged such that when the seat pan/seat assembly is in the seating configuration, the lumbar support is configured to provide (in conjunction with the backrest) lumbar support to a passenger sitting in the seat. As the seat pan is actuated into the intermediate configuration, the seat pan forms a slightly larger angle to the backrest, and the lumbar support continues to provide at least some lumbar supporting configuration. However, as the seat pan is actuated into the lie-flat configuration, the lumbar support moves into a flat configuration where it is substantially coplanar with the seat pan and the backrest. Details of the way in which the linkage moves, and the seat pan and lumbar support interact, are provided below.

Figures 1 to 3 show a seat assembly 100 according to an embodiment of the invention. The seat assembly 100 has a base 101, a seat carriage 103, a seat pan 105, a lumbar support 107, and a backrest 109. The seat assembly 100 also has a headrest 102 attached to the seat carriage 103 and a leg rest 160 pivotally attached to the seat pan 105. The backrest 109 is fixedly attached to the seat carriage 103. The seat carriage 103 has a curved rail 111. The curved rail 111 sits within the base 101 and the radius of the curve of the curved rail defines an arcuate path through which the curved rail passes when it is moved through rollers/guide wheels 113 in the base 101.

The curved rail 111 of the seat carriage 103 passes through the rollers 113 of the base 101 to adopt different configurations. The configuration shown in Figure 1 is a seating configuration in which the seat 100 is arranged for a passenger to sit in it upright, for example during Taxi, Take-Off and Landing (TTOL), food service, or regular use of the seat. Figure 2 shows the seat in a flat-bed configuration, in which (in comparison to Figure 1) the curved rail 111 has passed through the rollers 113 of the base 101, such that the backrest 109 is in a near horizontal position, and the lumbar support 107 and the seat pan 105 are substantially coplanar with each other and the backrest 109. The flat-bed configuration is suitable for a passenger to sleep on. Figure 3 shows an intermediate "Zero-G" configuration, which the seat 100 is in when the curved rail 111 is held part-way through the base 101. When the curved rail 111 is in this intermediate position it is between the position it occupies while the seat 100 is in the seating configuration and the position it occupies when the seat is in the flat-bed configuration. When the seat 100 is in the seating configuration, the backrest 109 and the lumbar support 107 form a convex surface (the surface which faces outwardly, towards the back of a passenger). The seat's convex shape supports the passenger's back in the lumbar region of the spine. The convex relationship between the backrest 109 and the lumbar support 107 is shown by dashed line 115.

When the seat is in the "Zero-G" (or -lazy Z") configuration, shown in Figure 3, the relationship between the backrest 109 and the lumbar support is convex and provides support similarly to the first position, whilst the seat is in a recline position. The convex relationship between the backrest 109 and the lumbar support 107 is still present (albeit marginally less pronounced in comparison to the seating configuration), when the seat is in the "Zero-G-configuration. The extent of the lumbar support's 107 convex deflection from the backrest 109 is defined by the relative position of the seat pan 105 and the lumbar support 107, as discussed further below.

When the seat is in the flat-bed configuration, shown in Figure 2, the seat pan 105 is substantially coplanar with the lumbar support 107 and the backrest 109. In this configuration there is substantially no convex relationship between the backrest 109 and the lumbar support 107, and the backrest 109, lumbar support 107 and seat pan 105 form part of a substantially horizontal flat-bed surface.

As is visible in Figure 1, the backrest 109 is fixedly attached to the seat carriage 103 by attachments 110 at the two ends of the backrest. Thus, the backrest substantially does not move relative to the seat carriage 103. The lumbar support 107 is pivotally attached to the seat carriage 103 at pivot attachment 108 (lumbar pivot 108). The lumbar support 107 has a first end, proximate to the backrest, and a second end, proximate to the seat pan, and the lumbar support pivot 108 is located at the first end of the lumbar support. The seat pan is pivotally attached to the seat carriage 103 at pivot attachment 106 (seat pan pivot 106).

The curvature of the seat carriage is such that the centre of curvature of the rail is a position forward of, and above (when the seat unit is in the flat-bed configuration), the seat unit. This enables the movement shown in Figures 1-3, -12 -wherein when the seat assembly moves from the seating configuration to the intermediate "Lazy Z/Zero G" configuration, the rear portion of the seat pan 105 (i.e. where the passenger's hips would be located if occupying the seat) is lowered relative to the position in the seating configuration and relative to the front portion of the seat pan 105. The rear portion of the seat pan 105 is then raised as the seat assembly moves into the flat-bed configuration.

As shown in the description of Figures 1-3, the seat assembly of the first embodiment is configurable into three configurations. It has been recognised that a lumbar support is desirable in the seating and lazy Z configurations, but is undesirable in a flat bed. In the first embodiment of the invention, the seating assembly is configured to ensure the lumbar support forms a coplanar surface in the bed configuration, as will now be described with reference to Figures 4a-4h.

Figures 4a-4h show the interaction between the seat pan 105 and the lumbar support 107. The lumbar support 105 has an arm 117 with a follower pin 119 extending laterally from it. The seat pan 105 has an arm 121 with a guide groove 123 formed within it. As shown in more detail in Figures 17 and 18, the follower pin 119 of the lumbar support arm 117 is received within the guide groove 123.

The figures 4a-4h in alphabetical order, show the interaction between the lumbar support 107, the arm 117 and follower 119, and the seat pan 105, the arm 121 and the guide 123 during movement of the seat pan about the seat pan pivot 106. As the seat pan 105 pivots around seat pan pivot 106, the follower 119 travels along the guide 123. The shape of the guide groove 123 is a constant radius. The movement of the seat assembly into the lazy-Z configuration is such that there is relatively little relative rotation between the backrest and the seat pan; because there is relatively little movement of the seat pan (relative to the backrest) it does not create significant changes to the orientation of the lumbar support (relative to the backrest). After the seat pan is moved through its initial rotation shown in figures 4a-4d, there is therefore still provided some lumbar support in the intermediate configuration/lazy Z configuration. The guide grove is such that further rotation of the seat pan, shown in figures 4e-4h, causes further pivoting of the lumbar support about lumbar support pivot 108 from the lumbar support configuration to the flat configuration. Thus, when the seat 100 is arranged in the seating configuration and the intermediate/Lazy Z configuration, the interaction between the seat pan 105 and the lumbar support 107 is such that the lumbar support 107 is in a lumbar supporting 1 - - configuration. However, as the seat pan 105 pivots to create a greater angle between the seat pan 105 and the backrest 109, the lumbar support 107 also pivots into a position where the lumbar support 107 forms a less convex relationship with the backrest 109. As the seat pan 105 is pivoted into position so that the seat adopts a flat-bed configuration, the lumbar support 107 is correspondingly pivoted (by the interaction between the guide 123 and the follower 119 of the seat pan 105 and the lumbar support 107 respectively) such that the lumbar support 107 adopts a flat configuration. Thus, the backrest 109, lumbar support 107 and the seat pan 105 move between a seating position with lumbar support, to a flat-bed position with coplanar cushions, without requiring an additional actuator to actuate the lumbar support 107 directly (as this is indirectly actuated by an actuator actuating the seat pan).

Figures 5 to 23 show parts, and groups of parts, of the seat assembly described above, in detail: Figures 5 and 6 shows the base 101 of the seat assembly 100. The base comprises a frame 133 to which is mounted an actuator (motor) 130 for driving a pinion 151 which engages with a rack (part of curved rail 111, shown in detail in figures 8 and 9) of the seat carriage 103 (not shown in Figures 5 and 6) and guide wheels 113 for guiding the curved rail 111 of the seat carriage 103.

Figure 7 shows the seat carriage 103 with the backrest 109 and the headrest 102 fixedly attached to it. The seat carriage 103 further comprises a seat pan mount 104 which comprises the seat pan pivot 106 to which the seat pan 105 is pivotally attached and around which the seat pan 105 pivots.

Figure 8 shows a rear view of the seat carriage 103 as shown in figure 7, which shows the profile of the curved rail 111. The curved rail 111 has inner H2 and outer 114 lips. Figure 9 shows a close up rear view of the base 101 with the seat carriage 103 in-situ. As shown in Figure 9, the outer lips 114 of the seat carriage 103 curved rail 111 rest in and are guided by guide wheels 113. Figure 10 shows a perspective front view of the base 101 with the seat carriage 103 in-situ. As shown in Figure 10, the upper surface of the outer lips 114 of the seat carriage 103 curved rail 111 are also guided by guide wheels 113. On each side of the carriage, between the inner 112 and outer 114 lips, and on the rear face of the carriage, there is a rack 150. The rack 150 is suitable for engagement by a toothed wheel, such as the pinion 151. The pinion 151 is driven by an actuator 130.

-14 -Figure 11 shows a perspective view of the seat carriage 103 of figure 7, without the backrest 109 or the headrest 102 in place, and shows the shape of the seat carriage behind the backrest 109 and the headrest 102. Figure 12 shows a side view of the seat carriage 103, and shows the profile of the seat carriage 103.

Figure 13 shows a front view of the seat carriage 103 and also shows the profile of the inner 112 and outer 114 lips of the curved rail.

Figure 14 shows the seat pan 105 in side view. The seat pan has a cushion 128, leg rest attachment point 127, arm 121 and the arm comprises a guide 123, which is curved. Figure 15 shows the seat pan 105 from a different perspective, and shows that there are two arms 121 with guides 123. The seat pan 105 also comprises an actuator attachment point 129, disposed between the arms 121 and substantially centrally within the seat pan 105. The seat pan 105 also comprises a seat pan pivot attachment 126, which attaches pivotally to the seat carriage 103. The seat pan pivot attachment is located in a rear portion of the seat pan 105. The leg rest attachment point 127 is arranged at the front of the seat pan 105 and is suitable for a pivotal connection to a leg rest 160.

Figures 16 and 17 show the lumbar support 107 in isolation. The lumbar support has a lumbar cushion 131, a lumbar support attachment point 116, an arm 117 and a follower 119. The lumbar support attachment point is suitable for pivotal connection to the seat carriage 103.

Figure 18 shows the seat pan 105 and the lumbar support 107 together. The arm 121 of the seat pan 105 sits within the width of the arm 117 of the lumbar support 107. The follower 119 of the lumbar support 107 runs through the arms of both the lumbar support 117 and the seat pan 121. This arrangement could be inverted such that the seat pan had an arm with the features of the lumbar support arm, and vice versa.

Figure 19 shows a similar view to figure 18, but also shows a seat pan actuator 142 which can retract and extend the actuator rod 141 relative to the actuator body 140. The seat pan actuator 142 shown in Figure 19 is a linear actuator. The end of the actuator rod 141 is connected to the actuator attachment point 129, and the actuator body is connected to the seat carriage 103, as shown in Figure 20, Figure 20 shows a rear view of the seat assembly 100 with the seat pan actuator 142 in place and connected to the seat pan 105. The seat pan 105 is rotated when the rod 141 of the actuator 142 is moved relative to the actuator body 140. With reference to figures 4a- -15 - 4h, the actuator would be at a position of maximum (or near maximum) extension in figure 4a, and through the movement shown in Figures 4a-4h the actuator rod retracts to a point of maximum (or near maximum) retraction at the position of the seat pan shown in Figure 4h. To move the seat pan 105 in the opposite movement (from the flat-bed to the seating position shown in Figures 4h-4a (i.e reverse order), the actuator 142 extends.

Figures 21 to 23 show the seat assembly 100 without the base 101.

Figure 24 shows a layout of passenger accommodations (LOPA) which this seat assembly 100 is suitable for use in. The LOPA comprises the seat assemblies 100 arranged in an outboard facing herringbone. Figure 25 also shows a LOPA in a second embodiment. In the second embodiment the seat assemblies 100 are in a mixed inboard-facing/outboard-facing herringbone. The same seat assemblies 100 may be used between the two different layouts. The outboard column (that is, the column adjacent the windows of an aircraft) is an outboard-facing herringbone. The seat assemblies may be used on a narrow body aircraft having two outboard columns as shown in Figures 24 and 25, with no central column of seats.

In a third embodiment, shown in Figures 26 to 28, the seat assembly is surrounded by seat furniture so as to form a seat unit. The seat assembly 200 comprises all of the same features as the seat assembly 100 of the first embodiment.

Thus, like reference numerals (separated by 100, e.g. reference numeral 127 of the first embodiment becomes 227 in the third embodiment) of the first embodiment correspond to the same features of the third embodiment which might not be shown in the figures depicting the third embodiment. The leg rest 260 is pivotable around the leg rest attachment point 227. The leg rest is actuated relative to the seat pan by an actuator (not shown). The actuator could be a linear actuator, or a rotary actuator or any device suitable for pivoting the leg rest relative to the seat pan 205 about the leg rest attachment point 227.

Figure 26 shows the seat assembly 200 in the seating configuration, wherein the leg rest is tucked under the seat pan 205. Figure 27 shows the seat assembly 200 in the flat-bed configuration, wherein the leg rest 260 forms a flat surface with the seat pan 205, lumbar support 207 and the backrest 209. Figure 28 shows the seat assembly 200 in a "Zero-G" or "Lazy Z" configuration which is between the seating configuration and the flat-bed configuration.

-16 -The seat assemblies of the first and/or third embodiments can be used in the LOPA shown in Figure 24 as part of the first embodiment, or the LOPA shown in Figure 25 (the second embodiment).

In a fourth embodiment, the lumbar support is alternatively arranged, wherein the linkage arms 117/119 of the first embodiment are positioned towards the centre of the lumbar support/seat pan, and the arm of the seat pan is arranged to be sandwiched between a split in the arm of the lumbar support, as discussed below: Figures 29a-29h show the interaction between the seat pan 405 and the lumbar support 407. The lumbar support 405 has an arm 417 which is split into two sides with a follower pin 419 extending laterally from it and between the two sides of the arm 417. The seat pan 405 has an arm 421 with a guide groove 423 formed within it. As shown in more detail in Figures 30 and 31, the lumbar support arm 417 is split such that it can receive the seat pan arm 421 between the two sides of the arm 417, with the follower pin 419 extending through the guide groove 423.

The figures 29a-29h in alphabetical order, show the interaction between the lumbar support 407, the arm 417 and follower 419, and the seat pan 405, the arm 421 and the guide 423 during movement of the seat pan about the seat pan pivot 406. As the seat pan 405 pivots around seat pan pivot 406, the follower 419 travels along the guide 423. The shape of the guide groove is a constant radius car. The movement of the seat assembly into the lazy-Z configuration is such that there is relatively little relative rotation between the backrest and the seat pan. Because there is relatively little movement of the seat pan (relative to the backrest) it does not create significant changes to the orientation of the lumbar support (relative to the backrest) (so that after the seat pan is moved through its initial rotation shown in figures 29a-29b, there is still provided some lumbar support in the intermediate configuration/lazy Z configuration). The guide grove is such that further rotation of the seat pan, shown in figures 29b-29h, causes further pivoting of the lumbar support about lumbar support pivot 408 from the lumbar support configuration to the flat configuration.

Figure 31 shows a similar view to figure 30, but also shows a seat pan actuator 442 which can retract and extend the actuator rod 441 relative to the actuator body 440. The seat pan actuator 442 shown in Figure 31 is a linear actuator. The end of the actuator rod 441 is connected to the actuator attachment point 429, and the actuator body is connected to the seat carriage 403, as shown in Figure 32. Figure 32 shows a rear view of the seat assembly 400 with the seat pan actuator 442 in place and -17 -connected to the seat pan 405. The seat pan 405 is rotated when the rod 441 of the actuator 442 is moved relative to the actuator body 440.

Whilst the present invention has been described and illustrated with reference to particular embodiments, it will be appreciated by those of ordinary skill in the art that the invention lends itself to many different variations not specifically illustrated herein. By way of example only, certain possible variations will now be described. Where in the foregoing description, integers or elements are mentioned which have known, obvious or foreseeable equivalents, then such equivalents are herein incorporated as if individually set forth. Reference should be made to the claims for determining the true scope of the present invention, which should be construed so as to encompass any such equivalents. It will also be appreciated by the reader that integers or features of the invention that are described as preferable, advantageous, convenient or the like are optional and do not limit the scope of the independent claims. Moreover, it is to be understood that such optional integers or features, whilst of possible benefit in some embodiments of the invention, may not be desirable, and may therefore be absent, in other embodiments.

Claims

-1 8 -Claims I. A passenger seat assembly for an aircraft, the seat assembly being configurable between a seating configuration and a flat-bed configuration, the seat assembly comprising; a base for connection to the floor of the aircraft and a seat carriage comprising a curved rail; a backrest attached to the seat carriage; a lumbar support pivotally attached to the seat can at a first pivot; and a seat pan pivotally attached to the seat carriage at a second pivot; wherein the seat carriage is supported by the base and the curved rail of the seat carriage is moveable relative to the base, thereby moving the seat carriage along an arc defined by the curvature of the curved rail; and wherein the seat pan and the lumbar support are arranged such that articulation of the seat pan about the second pivot causes articulation of the lumbar support about the first pivot between; a lumbar-supporting configuration wherein the lumbar support and the backrest are angled with respect to one another; and a flat configuration where the backrest and lumbar support are substantially 20 coplanar.
2. A passenger seat assembly according to claim 1, wherein the lumbar support has a first end, proximate to the backrest, and a second end, proximate to the seat pan, and the lumbar pivot is located at the first end.
3. A passenger seat assembly according to claim 2, wherein the second end of the lumbar support occupies a position further towards the seat carriage when in the lumbar-supporting configuration than when in the flat configuration
4. A passenger seat assembly according to any preceding claim, wherein the backrest is fixedly attached to the seat carriage.
5. A passenger seat assembly according to any preceding claim, wherein the passenger seat assembly further comprises a headrest, the headrest being fixedly attached to the seat carriage
6. A passenger seat assembly according to any preceding claim, wherein when the seat pan is co-planar with the backrest, the lumbar support is in the flat configuration
7. A passenger seat assembly according to any preceding claim, wherein the seat pan and lumbar support are connected by a guide and a follower, wherein one of the seat pan or the lumbar support is associated with the guide and the other of the lumbar support or the seat pan is associated with the follower arranged to be moveable within the guide.
8. A passenger seat assembly according to any preceding claim, wherein the base comprises a carriage actuation assembly configured to move the carriage relative to the base.
9. A passenger seat assembly according to claim 8, wherein the carriage actuation assembly comprises a rack and pinion and an actuator, the curved rail of the carriage comprises the curved rack and the base comprises the pinion, and wherein rotation of the pinion is effected by the actuator.
10. A passenger seat assembly according to any preceding claim, wherein the seat assembly further comprises a seat pan actuator for effecting movement of the seat pan, the seat pan actuator comprising a linear actuator connected at one end to the seat carriage and at its opposing end to the seat pan.
11. A passenger seat assembly according to claim 10, wherein retraction of the seat pan actuator causes the lumbar support to adopt the flat configuration.
12. A passenger seat assembly according to any preceding claim, wherein the seat assembly is configurable into an intermediate configuration in which the curved rail -20 -is moved part-way between its relative positions in the seating configuration and the flat-bed configuration, wherein in the intermediate configuration the backrest is at a reclined angle, the lumbar support is in the lumbar supporting configuration, and the root end of the seat pan is lowered relative to the front end of the seat pan.
13. A passenger seat assembly according to any preceding claim, wherein the seat assembly further comprises a leg rest, pivotally attached to the seat pan.
14. A passenger seat assembly according to claim 13, wherein the leg rest is rotatable relative to the seat pan between a stowed position, in which the leg rest is at an angle to the seat pan, to a bed position, in which the leg rest is substantially coplanar with the seat pan.
15. A passenger seat assembly according to claim 14, wherein the leg rest is moveable by means of a linear actuator attached at one end to the seat pan and at the other end to the leg rest.
16. A passenger seat assembly for an aircraft, wherein the passenger seat assembly comprises a base and a carriage, the base comprising a toothed wheel, and the seat carriage comprising a curved toothed rack, the curved toothed rack and the toothed wheel being arranged to interface such that rotation of the toothed wheel moves the curved rack along an arcuate path relative to the base, wherein the seat assembly further comprises a backrest, a lumbar support and seat pan attached to the curved rail; and wherein the seat assembly is arranged to be configurable between: an upright position in which the backrest, lumbar support and seat pan are positioned in a seating position to provide an upright seating surface; a zero-g reclined position in which the backrest, lumbar support and seat pan are positioned in a reclined position such that a rearmost portion of the seat pan is lowered relative to a foremost portion of the seat pan; and a flat-bed configuration in which the backrest, lumbar support and the seat pan are substantially coplanar.
17. A kit of parts for forming a seating assembly, the kit of parts comprising: a base comprising a pinion; and a seat carriage comprising a curved rail having a curved toothed rack; and a backrest, a lumbar support and a seat pan, the backrest, a lumbar support and a seat pan being configurable to attach to the seat carriage.
18 A seating arrangement in the cabin of a passenger aircraft, the arrangement comprising a column of the seat assemblies according to any of claims 1 to 16.
19. A seating arrangement according to claim 18, wherein the seat assemblies are arranged in a herringbone formation in which consecutive seating assemblies in the column are orientation at an acute angle to the longitudinal axis of the aircraft cabin
20. A seating arrangement according to claim 19, wherein the seating assemblies are adjacent a sidewall of the aircraft and face outwardly towards the sidewall.