Patent Description:
In a living space where space is restricted - for example, in a caravan, a camper van, boat or trailer tent - it is well known to provide seats which can convert into a bed. In its simplest form, this is achieved by turning over a seat cushion.

In the front of most caravans, a pair of seats face one another and extend parallel along the sides of the caravan. A space is provided between the seats, which enables both seats to be used and the occupants can face one another. The seat cushions typically rest on bases, which usually have some storage space within, and backrest cushions extend up the side walls of the caravan. This arrangement is usually adapted to convert into a double bed.

Typically, a number of slats, provided on fabric tapes are located in a cupboard and can be extended through the space. The slats are supported at their ends on the bases and when fully extended, provide support for cushions between the bases.

To complete the bed, the base cushions are turned over and the backrest cushions are placed face down on the slats to completely fill the space. The cushions are turned because they are upholstered on one side with button upholstery on one side for seating, but are upholstered flat on the other side for sleeping. The seat cushions are also usually bolstered on a front edge, to give extra support when seated. This means that the cushions, when turned, are not flat across the bases and slats.

It will be appreciated that to convert from the seating arrangement to the sleeping arrangement is a highly physical process, because large cushions have to be turned and placed. Furthermore, a topper is often placed onto the bed to even out the surface. After this, bedding has to be placed over the topper. All in all, the conversion is very time-consuming, physical and awkward. The bed, once assembled, can only be accessed from one end, and so putting a sheet on the topper and laying out a duvet and pillows involves climbing over the bed.

<CIT> relates to furniture and more particularly to the type in which there is provided a bottom member adapted to occupy an inner position where it acts as a seat and an outer position where it acts as an extension for the furniture to provide a bed bottom or other reclining surface.

<CIT> relates to a piece of seating furniture that can be converted into a bed, consisting of a seat part, a back part that can be folded down and a swivelling exchangeable cushion, which can be placed on the seat part in the sitting position and on the horizontal back part in the lying position, and the strength of which, together with that of the back part, is the same as that of the seat part, according to the invention, to bridge the joint between the seat and back part with the replacement cushion, the seat part has a shoulder on its edge adjacent to the back part, the depth of which is equal to the thickness of the replacement cushion engaging in the shoulder when used as a lounger and the width of which corresponds to the difference between surface width of the seat part corresponds to that of the back part.

<CIT> relates to a convertible sofa characterised by a compensation suspension which is attached to the front wall of the bed support and to the edge of the rear folding frame arranged near to the floor in the seating position, by a support wedge arranged on the rear folding frame, and by a cushion which is attached releasably to the rear upper edge of the second back cushion in the seating position. In order to be able to reduce the seat depth, provision is made according to the invention for a pivoting cover to be attached to the rear upper edge of the seat cushion, the seat cushion of the pull-out frame being reinforced by the thickness of the pivoting cover relative to the second back cushion and the first back cushion so that the pivoting cover results in a horizontal surface in the lying position when it has been pivoted through <NUM> DEG onto the two back cushions.

<CIT> relates to furniture for sitting and lying down, in which an upholstered back part can be brought into a horizontal position and in this position with its upholstered surface together with a seat upholstery forms a lying surface, with a protective sheet or the like being provided, which in the lying position covers the entire lying surface of the back and seat cushion can be brought.

It is an object of the present invention to reduce or substantially obviate the aforementioned problems.

According to a first aspect of the present invention, there is provided a seat as set out in claim <NUM>. Optional features are presented in the dependent claims.

This enables a seat to be quickly and easily converted between uses, for sitting on the squab or sleeping on a mattress formed by the squab and backrest. The backrest cushion is moved together with the squab into and out of the bed configuration, and does not need to be moved or handled separately. The mechanism automates the conversion between each configuration, reducing the effort required to convert the seat to a bed (and back to a seat). Concealing a bed area within the squab means that only part of the squab needs to be flipped over, rather than the whole cushion, which further reduces the efforted involved. This also saves a significant amount of time when converting the seat/bed to the other configuration. The backrest effectively moves into the space vacated by the squab as it is vacated during the conversion to a bed configuration due to its link to the squab or part of the conversion mechanism.

The backrest may be connected to the lower cushion. The backrest may be connected to the upper cushion. The upper and lower cushions are connected. The backrest may be connected to a rear part or rear side of the squab, for example. In the seat configuration, the backrest may be disposed above a rear part or rear side of the squab, such as above the lower cushion but not the upper cushion, for example. The backrest may be disposed rearwards of the upper cushion in the seat configuration (taken relative to the front of the seat). The upper cushion may be sized to substantially match the width and/or height of the backrest. The upper cushion may have a thickness which substantially matches a difference in thickness between the backrest and the lower cushion.

Bedding may be connected or fitted to the squab. The bedding may include a sheet and/or a duvet for covering the bed area.

This provides bedding which is stored in and integral with the seat. When the seat is converted into the bed configuration, the bedding is pre-made and ready for use. The bedsheet is quite thin, and so does not significantly distort the shape of the squab in the seat configuration, when stored away. However, a duvet is thicker. A pocket may be formed in the squab between the top and base portions for containing a duvet. In the seat configuration, the bedding may be sandwiched between the squab portions. Depending on the size of the bed, custom-sized bedding may be provided.

The upper cushion of the squab is adapted to cover the backrest during lateral displacement of the squab into the second position. The upper cushion of the squab is adapted to move onto the lower cushion during lateral displacement of the squab into the first position. According to the invention, the upper cushion of the squab is tethered to a lower region. Lateral displacement of the squab causes inversion of the upper cushion.

When converting the seat into the bed configuration, the upper cushion needs to be displaced away from the lower cushion to reveal the sleeping surface for use in the bed configuration. By tethering the upper cushion to a particular region, lateral displacement of the squab effects movement of the upper cushion. This enables displacement of the different elements to occur substantially in concert. For example, the upper cushion may be tethered to a point or area underneath the base cushion of the squab. The tether(s) may extend through or around the base cushion.

The upper cushion of the squab may be disposed on top of the backrest in the bed configuration for providing a flat surface for sleeping on. The total thickness of the backrest and the upper cushion of the squab overlying the backrest may be substantially the same as the thickness of the base cushion of the squab.

The backrest is typically less thick than the squab, because the squab is designed to receive a bigger load in use. The thickness of the upper cushion is selected to complement the thickness of the backrest. By doing so, the thickness of the mattress formed by the backrest and the upper cushion, and the adjacent base cushion of the squab, is substantially uniform in all regions. This provides a surface which is more comfortable to sleep on.

A boundary between the backrest and the lower cushion may be offset from another boundary between the lower and upper cushions of the squab, when the seat is in the bed configuration. In other words, the vertical 'join' where the backrest meets or abuts the lower cushion is in a different position to the vertical 'join' where the upper cushion meets or abuts the lower cushion. Preferably, the upper cushion covers the boundary between the backrest and the lower cushion in the bed configuration.

This provides a mattress (in the bed configuration) which does not have a straight boundary or join extending without interruption through its body. There are instead first and second joins which are offset from each other. The term 'join' refers to an interface, not a fastening. Consequently, when load is applied on top of either join, the degree of cushion spreading is minimal, and so it is more comfortable to sleep on. In the case of the backrest and lower cushion boundary, the top cushion can distribute the load to either side to minimise cushion separation. For the upper/lower cushion boundary, the lower thickness of the upper cushion compared to the lower cushion means that the height of the boundary through the mattress is minimal, and so any cushion separation under load is negligible.

A ramp element (or elements) may be provided adjacent to the backrest. The ramp element is preferably below the backrest. The ramp element is also preferably behind the squab. A rear portion of the backrest may be contoured to complement the ramp element for aiding movement between the seat and bed configurations.

The ramp element reduces the frictional barrier to pulling or pushing of the backrest during the transition from seat configuration to bed configuration, or vice versa. When the squab is moved laterally to its second (bed) position, the backrest is pulled from an upright position into a horizontal position. The ramp and curved rear of the backrest cooperate to enable a smooth transition. The same applies in the reverse operation, when movement of the squab pushes the backrest back into an upright position.

The bedding may be releasably connected to the squab. The releasable connection may be provided by at least one of the following: poppers, buttons, one or more zips, magnetic clips, hook and loop fasteners.

This enables the bedding to be easily removed for washing. It also means that the bedding remains substantially fitted in place during storage in the seat configuration, and should not need to be re-made once the seat is opened into the bed configuration.

The bedding of one seat may have complementary connection means for connection to the bedding of another seat. This is useful where two seats are provided for use together as a double bed. It is usually not necessary to connect the bed sheets together, but it is useful to connect the duvet sections together to provide a single duvet across both seats in the bed configuration.

A rollable or slidable support may be provided in the seat. The squab may be connected to and moveable with the support. The conversion mechanism may be configured to move the support. The support may be a frame.

The support provides a structure under the squab to support it in the laterally-displaced position in the bed configuration. Having a rollable or slidable portion in the support makes the conversion process smoother and avoids damaging the floor.

The support may include at least one floor-engaging wheel. The wheel may include a spring mechanism or biasing mechanism configured to substantially disengage the wheel from the floor when a load is applied to the seat.

Using sprung wheels or similar ensures that the support does not move when the bed is occupied. When the occupant(s) have vacated the bed, the wheel re-engages the floor sufficiently to enable movement of the frame again, and so the bed configuration can be readily converted into the seat configuration.

The conversion mechanism may include at least one actuator. A control may be provided for operating the or each actuator.

The actuator can exert a linear force on part of the seat to extend or retract the squab, and convert the seat between configurations. This makes automatic conversion of the seat effectively effortless. Providing a control enables this to be done at the press of a button, for example.

The seat may be lockable in the bed configuration. This prevents inadvertent conversion of the bed configuration into the seat configuration, which could cause injury if the bed is occupied at the time.

The upper and lower cushions of the squab may both be substantially flat. The cushions may each have a cross-section of uniform thickness. This contributes to having a substantially flat mattress in the bed configuration without uncomfortable bumps.

The lower cushion may be longer than the upper cushion. In the bed configuration, the upper cushion may cover the backrest and a rear portion of the lower cushion. The squab may have a roughly L-shaped side profile or cross-section in the seat configuration, and a rectangular side profile or cross-section in the bed configuration (when the upper cushion is on top of the backrest which abuts the lower cushion).

This allows a thinner rear portion of squab to be provided, and the backrest can be correspondingly less tall. This avoids needing to have an uncomfortably high backrest in order to provide a long enough bed. This also helps to offset backrest to lower cushion interface from the lower cushion to upper cushion interface (i.e. the joins between the different parts do not line up).

According to a second aspect of the present invention, there is provided a seat arrangement comprising a seat according to the first aspect of the invention, and a second seat disposed opposite the first seat.

The seats may be separated by a gap when the seats are in their respective seated configurations. One of the squabs may span the gap in its bed configuration. Both of the squabs may together span the gap. The gap provides leg room in the seat configuration.

Preferably, the second seat is also a seat according to the first aspect of the invention.

If one seat with a conversion mechanism is provided, it can span the full gap to the other seat. If two seats with conversion mechanisms are provided, the seats can meet halfway across the gap. It may be that one seat extends more than halfway across the gap, and the other seat extends across the difference. This can provide the boundary between the two lower cushions of the respective squabs in a location which is less likely to bear a load, and so the user is less likely to feel discomfort when sleeping on the bed configuration of the seats.

The seat or seat arrangement may be installed in a vehicle selected from the following group: a caravan, a boat or seafaring vessel, a bus, a car, a van, a train, an aeroplane. Alternatively, the seat or seat arrangement may be provided in a building, for example: a house, an apartment, or a hotel.

The second aspect of the invention may include one or more features presented with respect to the first aspect of the invention.

For a better understanding of the present invention, and to show more clearly how it may be carried into effect, reference will now be made by way of example only to the accompanying drawings, in which:.

Referring firstly to <FIG>, an embodiment of a seat arrangement is indicated generally at <NUM>. The seat arrangement <NUM> includes a first seat indicated generally at <NUM>, and a second seat indicated generally at <NUM>. The seats are separated by a gap <NUM>. Each seat <NUM>, <NUM> is shown in a seat configuration. Each seat <NUM>, <NUM> is shown in a corresponding bed configuration in <FIG>. The seats <NUM>, <NUM> are moveable or interconvertible between these configurations.

The seat arrangement <NUM> is depicted adjacent to a chest of drawers <NUM> and tables 14a, 14b. These elements are typically found in a vehicle such as a caravan, which is where the seat arrangement of this embodiment is located. The tables 14a, 14b may be replaced by cushions.

Each seat <NUM>, <NUM> is substantially identical in this embodiment. The following description will refer primarily to just one of the seats <NUM>, <NUM> for brevity. Unless noted otherwise, elements described with respect to the first seat <NUM> (numbered parts of the form 1xx, where x is a number) should be assumed to have an equivalent part (numbered 2xx) present on the second seat, even if such parts are not explicitly labelled.

The seat <NUM> is mounted on a unit <NUM>. The unit <NUM> is a wooden or MDF box that forms part of a caravan. A frame <NUM> is fitted on the unit <NUM>. The frame <NUM> is made of aluminium for its low weight and good strength, but any suitable material can be used.

With particular reference to <FIG>, the frame <NUM> includes a support surface <NUM>. The frame <NUM> also has first and second legs <NUM> disposed at either end of the unit <NUM>. Each leg <NUM> includes a wheel <NUM>. Each wheel <NUM> includes a spring arrangement (not shown). The unit <NUM> includes recesses 16a for receiving the wheels <NUM> when the seat <NUM> is in a seat configuration. In the bed configuration, the legs support the centre of the bed.

When there is effectively no load on the wheels <NUM>, the wheels are floor-engaging and enable the frame <NUM> to roll forwards and backwards relative to the unit <NUM>. When weight is applied to the frame, particularly when it is laterally displaced from the unit <NUM> as shown in <FIG>, the spring arrangements allow the wheel axles to move relative to the legs, which can touch the floor. This prevent the wheels from being placed under excessive load and allows the legs <NUM> to be the primary weight-bearing portion.

The seat <NUM> further includes two actuators <NUM>. In one embodiment, the actuators <NUM> are screw automated. Each actuator <NUM> is an extendible arm. Each actuator <NUM> is encased by a housing 108a. Each actuator <NUM> is electrically powered. A control (not shown) is provided to operate the actuators <NUM> on demand. In this embodiment, the control is linked to the actuators of both seats <NUM>, <NUM>. The control is a button in this embodiment.

Each actuator <NUM> runs from a 12V power source within the caravan in this embodiment. The frame <NUM> has cut out portions to accommodate each actuator <NUM> and housing 108a. An end of each actuator <NUM> is connected to the frame <NUM>, for pushing the frame into a bed configuration, or pulling the frame <NUM> into a seat configuration (depending on the starting configuration).

A ramp <NUM> is provided rearward of each actuator <NUM>. Each ramp <NUM> is connected to the respective actuator housing 108a in this embodiment. Each ramp <NUM> has a curved surface. The curved surface is concave. The ramp <NUM> is approximately a quarter-circle. In some embodiments, the ramp <NUM> can tangentially blend into a surface of the unit <NUM>.

Referring again to <FIG>, cushions are shown on top of the frame <NUM>. One of the cushions is a seat squab <NUM>, which is connected to a flat area <NUM> of the frame <NUM>. The squab includes a forward portion 120a and a rearward portion 120b of different thicknesses. The rearward portion 120b has a reduced thickness relative to the forward portion 120a. In this case, the difference in thickness is of the order of centimetres.

Another of the cushions is a backrest <NUM>, which is provided on one side of the seat squab <NUM>, to form a seat or sofa together with the squab <NUM>. The backrest <NUM> lies atop the rearward portion 120b of the squab <NUM> in this embodiment. The backrest <NUM> is connected to the squab <NUM>. Connecting elements (e.g. bars or arms, not shown) provide a flexible connection between the backrest <NUM> and squab <NUM>. The connecting elements are rigid enough for transferring pulling or pushing forces from the squab to the backrest when the seat is transitioning between a seat configuration and a bed configuration. The backrest <NUM> may in some embodiments be stitched to the squab <NUM>. Note that the ramp <NUM> is static in this embodiment. In other words, the ramp <NUM> does not change positions between seat and bed configurations of the seat.

Recesses or channels 122a are provided in a rear face of the backrest <NUM>. The channels 122a are shaped to complement the actuator housings 108a. An upper rear end 122b of the backrest 122b is curved. This curvature is selected to complement the curvature of the ramp <NUM>, to aid movement of the backrest <NUM> between the seat and bed configurations. The ramp <NUM> provides a bearing surface for moving the backrest <NUM> between horizontal and upright orientations.

The squab <NUM> can also be considered to include a base portion <NUM> and a top portion <NUM>. The base and top portions <NUM>, <NUM> are lower and upper cushions. Both portions <NUM>, <NUM> are flat on top. The base portion <NUM> is also flat-fronted for abutting the corresponding base portion of the second seat <NUM>. The base portion <NUM> includes the forward and rearward portions 120a, 120b. The top portion <NUM> is pivotally connected to the base portion <NUM>. The pivot <NUM> (shown in <FIG>) runs along a rear edge of the top portion <NUM>, at an end nearest the backrest <NUM>. The top portion <NUM> is stitched to the base portion <NUM> along the pivot <NUM> in this embodiment. The top portion <NUM> overlies the thicker forward portion 120a of the squab <NUM> in the seat configuration. The top portion is a few centimetres thick in this embodiment. The underside of the top portion <NUM> of the squab <NUM> is not upward-facing in the seat configuration. However, it forms part of a bed area in the bed configuration.

The top portion <NUM> is connected or tethered to part of the unit <NUM> in this embodiment. Tethers <NUM> are provided within the body of the squab <NUM>. The tethers <NUM> have a fixed length and are relatively inextensible. At one end, the tethers <NUM> are connected over the pivot <NUM> to an upward-facing surface (in the seat configuration) of the top portion. At the other end, the tethers <NUM> are secured to a corresponding portion of the unit, disposed below the first end. Tether points 130a are shown in <FIG>, for example. The tethers <NUM> extend through the squab <NUM>. In this embodiment, the tethers <NUM> are disposed at a boundary between the forward and rearward portions 120a, 120b. The frame <NUM> has cut out sections <NUM> to accommodate the tethers <NUM>.

Where a kit of parts is provided, for a caravan, for example, the frame <NUM> including wheels <NUM> is fitted to the unit <NUM> and the actuators <NUM> installed. The unit <NUM> and/or parts of the vehicle may need to be modified (e.g. portions cut out) to do this. The ramps <NUM> are installed, and then the cushions fitted on top. The squab <NUM> may be connected to the frame <NUM> using a hook and look fastener, for example. Alternatively, the frame <NUM> may have a lip that engages the squab <NUM>, or may have sufficient surface friction to engage and move the squab <NUM> between configurations.

Referring also to <FIG>, the top and base portions <NUM>, <NUM> are shown in further detail. A bed area <NUM> can be seen inside the squab <NUM> in <FIG>, which was substantially hidden from view by the top and base portions <NUM>, <NUM> in the seat configuration. Bedding (not shown) such as a bedsheet and a duvet is contained within that area <NUM>. The duvet of the first seat <NUM> includes connection means (e.g. fasteners) for connection to corresponding connection means on the duvet in the second seat <NUM>.

With particular reference to <FIG>, the seats <NUM>, <NUM> are shown in the bed configuration. The backrest <NUM> lies adjacent to an end of the base portion <NUM> of the squab <NUM>. The top portion <NUM> of the squab has been flipped over to lie on top of the backrest <NUM>. The combined thicknesses of the backrest <NUM> and top portion <NUM> match the thickness of the base portion <NUM>. This forms a mattress of substantially uniform thickness having a flat / level surface. Part of the support frame <NUM> is still supported by the unit <NUM> in the bed configuration.

A boundary <NUM> between the top and base portions <NUM>, <NUM> (i.e. at pivot <NUM>) is laterally offset from a boundary <NUM> between the backrest <NUM> and base portion <NUM>. This 'zig-zag' or staggering of the boundaries <NUM>, <NUM> ensures that compression on a particular part of the mattress does not cause substantial separation of two parts of the mattress formed by the cushions.

It can also be seen in <FIG>, for example, that lateral displacement of the squab <NUM> has created a space <NUM> where the rearward portion 120b used to be. The backrest <NUM> is pulled into that space <NUM> by movement of the squab <NUM>. This is done as part a concerted movement of the squab <NUM> and backrest <NUM>, in which case the backrest would enter/vacate the space <NUM> as the squab <NUM> vacates/entered that same space <NUM>.

For this purpose, the space <NUM> does not necessarily need to be an unoccupied space, but can be a region which is occupied by one or other of the squab <NUM> and backrest <NUM> according to the seat configuration.

<FIG> illustrate one of the tethers <NUM> which regulates movement of the top portion <NUM>. In <FIG>, the tether <NUM> is arranged around the top portion <NUM> and the forward portion 120a of the squab. In <FIG>, during movement of the squab <NUM>, the rearward portion 120b bears against the tether <NUM>. Due to the fixed length of the tether <NUM>, this exerts a force on the top portion <NUM>, rotating it about the pivot. Continued movement of the squab <NUM> as seen in <FIG> causes the rearward portion 120b to move over the anchor point of the tether <NUM>. This inverts the tether orientation. <FIG> shows the tether in the bed configuration, arranged around the rearward portion 120b of the squab <NUM>.

In use, the seat <NUM> can be in the seat configuration as in <FIG>. The control button is pressed to initiate the conversion from seat configuration to bed configuration. This causes the actuators <NUM> to extend, pushing the frame linearly outwards to displace it away from the unit <NUM>, towards the other seat <NUM>. The squab <NUM> moves with the frame, and the connection to the backrest <NUM> pulls the backrest forwards at the same time.

As this is occurring, the tethers <NUM> are redistributed and exert a force on the top portion <NUM> of the squab <NUM>. This rotates the top portion <NUM> about the pivot <NUM>, as seen in <FIG> and explained with respect to <FIG> above. The top portion <NUM> ends up in an inverted position on top of the backrest <NUM>.

Linear movement of the actuator <NUM> and squab <NUM> leads to translation and rotation of the backrest <NUM> into the plane of the squab <NUM>. It also leads to rotational movement of the top portion <NUM>, which levels off the backrest to form a planar surface for sleeping on. The movements of the actuator <NUM>, base portion <NUM>, backrest <NUM> and top portion <NUM> are all substantially concerted in this embodiment. However, it will be appreciated that the different events may occur at different rates, and begin and/or end at different times within the process.

As two seats <NUM>, <NUM> are provided, both seats <NUM>, <NUM> undergo this process. The seats <NUM>, <NUM> meet in the middle of the gap <NUM>. The resulting flat sleeping surface (which combines the bed areas of each seat) is at substantially the same height as the tables 14a, 14b in this embodiment.

The reverse operation, to convert the seat <NUM> to a seat configuration from a bed configuration, can also be performed. Again, the control button is pressed to initiate the conversion from seat configuration to bed configuration. The events described above occur in an opposite sense.

It will be appreciated that only one seat which is convertible between seat/bed configurations may be provided. The conversion process is substantially similar. It will also be appreciated that the process may be performed in a stepwise manner (performing the steps sequentially rather than concertedly).

Other embodiments may include additional or alternative features to those described above. For example, the vehicle may be a boat, a bus, a car, a van, a train, an aeroplane, instead of a caravan. The seat may be provided in a building, for example in a house, a hotel, or an apartment. If provided in a home, the seat or seat arrangement could be provided in a bedroom or in a living room or lounge, for example. The frames of opposing seats may have an interlock or other connections means to lock them together. There may be complementary connections on the frames so that they need to be at the same level in order to connect to each other, contributing further towards providing a flat sleeping surface by providing a combined, level frame.

In some embodiments, the bedding can be stored in a pocket formed between the portions of the squab. The bedding can be integrated with the squab. Releasable connectors can keep the bedding, e.g. a bedsheet, fitted to the squab.

Regarding the frame, instead of providing wheels, then casters or low-friction elements could be provided. Corresponding runners or low-friction strips could be provided on the floor. If the frame is sufficiently rigid and/or securely mounted to the unit in the vehicle, then legs may not be necessary to provide central support for the squab in the bed configuration. The frame could be suspended, or where two seats are provided the frames could interlock and support each other.

Claim 1:
A seat (<NUM>) moveable between a seat configuration and a bed configuration, the seat comprising
a squab (<NUM>) including upper and lower cushions (<NUM>, <NUM>), the upper cushion (<NUM>) being connected to the lower cushion (<NUM>),
a conversion mechanism configured to move the squab, for converting the seat between the seat and bed configurations, and
a backrest (<NUM>) connected to the squab or linked to the conversion mechanism, for moving with the squab,
the squab being laterally displaceable by the conversion mechanism between a first position in the seat configuration and a second position in the bed configuration, the backrest being configured to occupy a space (<NUM>) at an end of the squab substantially in concert with lateral displacement of the squab into the second position, the space being made available by lateral displacement of the squab, and the upper cushion of the squab being movable relative to the lower cushion for covering the backrest in the bed configuration,
wherein the upper cushion of the squab is tethered (<NUM>) to a lower region to cause inversion of the upper cushion by each of lateral displacement of the squab from the seat configuration to the bed configuration and lateral displacement of the squab from the bed configuration to the seat configuration.