RECLINING SEAT This invention relates to a reclining seat Airline Economy Class Seating is, by definition, less spacious than Business, Club or First Class seating. Minimum seat pitch (see Figure 1 MSP), the distance between the back of your seat and the back of the seat in front, ranges amongst the 29 largest scheduled and charter airlines from 737 mm to 864 mm. Personal passenger space (Figure 1 PPS) is the seat pitch reduced by the thickness of the seat back, often circa 51 mm, and this space is reduced again when the seat in front is reclined for comfort (Figure 1. RPPS). Between 1984 and 1999, the average seat pitch in business class rose from 36"to 55", while in economy class it fell from 34"to 32". Seats which more fully recline, such as may be found in premium cabins, require a greater seat pitch, ie more horizontal space, in order to provide additional rake for the seat back and additional space for a leg-raising support panel to be activated.

In addition, links between the immobility associated with cramped conditions and DVT (deep vein thrombosis) are gradually being established and challenges are being made to the airlines. But it is possible that several elements have been overlooked in the search for proof that the DVT link exists. When one is tired, the natural inclination is to want to lie down flat in order to relieve the body of the cumulative stress of standing or sitting and, of course, in order to sleep to restore the body to equilibrium.

In a fixed economy seat this is not possible, even with the seat back reclining through some 10-15 degrees. The situation is exacerbated when the cabin conditions are cramped. In an attempt to lie down, we sink progressively lower in the seat, moving our hips and legs forward as we attempt to stretch our legs out (see Figure 2). The unsupported head is inclined forward by circa 33 degrees, increasing the stress on an unsupported neck and there is a huge area from the shoulders to the base of the spine with no back or lumbar support. This ultimately results in several localised pressure points (see Figure 2) ; a line

across the back of the head (A), the unsupported neck (B), a line across the back of the shoulders (C), the lower back and lumbar region (D), the base of the spine and particularly the buttocks (E), the knee area (G) where it is restricted by the seat in front, a line across the underside of the upper leg (F) coinciding with the front edge of the seat, causing inhibited circulation, tingling or numbness in the affected areas and stress fatigue in the limbs, heels (H) and soles of the feet (J).

An object of this invention is to provide a reclining seat in which an internal seat cushion, back cushion and neck cushion assembly is permitted to move relative to an outer rigid seat chassis and relative to an outer back frame provided with limited rake adjustment, in such a way as to move the passenger from an upright sitting position to a reclined position and so that the inner back cushion assembly can recline at a greater angle from the vertical than the limited rake-adjustable outer back frame and the seat cushion assembly can move forward and downward relative to its original upright position, effectively lowering the torso closer to the floor and thereby effectively raising the occupant's legs relative to the floor, so that the seat will fully support the head and neck, the entire spine and the upper legs, alleviating pressure on the buttocks and the base of the spine, substantially reducing pressure points and stress on the lower limbs and feet and reducing the potential of restricted blood flow which may occur when the front edge of the seat presses into the back of the leg and achieving such movement, if used in an aircraft environment, within the seat pitch afforded to conventional fixed seats so as not to reduce the seat count and without impinging to any greater extent than a conventional design upon the personal space of the seats fore and aft of it, or in another application to provide a chair seat system that permits elderly, infrm or convalescing persons to access the chair in an upright position, activate the reclining mechanism for improved comfort, rest or sleep and return the seat to its upright position in order to vacate the chair.

According to the present invention there is provided an adjustable seat comprising a back rest portion, a seat portion coupled to the back rest portion for relative pivotal movement, first constraining means for constraining the seat portion for movement along a

first path having components in both a horizontal and vertical direction without permitting any substantial alteration in the attitude of the seat portion, and second constraining means for constraining the back rest portion for movement along a second path having components in both the horizontal and vertical directions with a corresponding alteration in the attitude of the back rest portion, whereby raising or lowering the seat portion causes a corresponding raising or lowering of the back rest portion accompanied by a change in the attitude of the back rest portion.

According to the present invention there is further provided an adjustable seat comprising a back rest portion coupled at its upper portion to a first guide inclined at a first angle to the horizontal to constrain the back rest portion at the point of coupling, for movement along said first guide, a seat portion pivotally coupled to a lower portion of the back rest portion and coupled to a second guide inclined at a second angle to the horizontal such that as it moves along the second guide the attitude of the seat portion remains substantially constant, the said second angle being smaller than the first angle.

Preferably, the first angle is substantially twice the magnitude of the second angle.

Advantageously, the first angle is in the range of from 1.25 to 2.25 of the second angle.

The second angle lies preferably in the range of from 30° to 40°.

In an alternative embodiment, the first guide comprises a dog-legged guide including an upper section inclined at the first angle, and a lower section articulate with the upper section and inclined at a third angle intermediate between the first and second angles.

In this case, the first, second and third angles are preferably between 80° and 90°, 65° and 75°, and 33. 5°and 43. 5° respectively. Also, a headrest may be provided that is pivotally connected to the backrest portion.

The first guide is advantageously a track, and the upper portion of the back rest is coupled to the track by a runner secured to the back rest, and engaging the track.

The second guide is advantageously a track and the seat portion has a runner rigid supported thereon and engaging the track.

The track may comprise a slot or a rail with a corresponding runner imprisoned therein or thereon.

The first and second guides may each comprise a pair of spaced tracks each coupled to a respective back rest portion and seat portion.

The seat portion includes at least one triangular support plate having one edge supporting a horizontal part of the seat portion and another edge carrying a pair of spaced runners engaging the track.

Advantageously, the back rest portion carries a neck support cushion and a lumbar support cushion.

The adjustable seat may include drive means for driving the upper portion along the first guide and/or driving the seat portion along the second guide.

The drive means may take the form of a rack and pinion driven by an electric motor.

Instead, the drive means may comprise a hydraulic or pneumatic piston and cylinder arrangement.

Advantageously, the back rest portion carries a pair of pivotal arm rests.

Accordingly, to the present invention there is also provided a reclining seat comprising a rigid seat chassis assembly, a back panel partially adjustable for rake and linked at the lower end thereof to the rear of or adjacent to the rear of the rigid seat chassis via a hinge, a retractable arm rest, linked at the rear end thereof to the rear of or adjacent to the rear of the seat chassis or to the lower end of the back panel via a hinge, a hinged contoured seat and back cushion assembly, a contoured neck and head rest, means for slidingly securing the neck and head rest to the back cushion assembly, means for slidingly

securing the hinged seat and back cushion assembly to, and within the sides of, the rigid seat chassis and the rake-adjustable back panel, the hinged seat and back cushions being provided with carriage plates and adapted to slide in guides mounted to and within the sides of the rigid chassis and the rake-adjustable back panel in order to permit the seat cushion to move further forward and lower than a conventional fixed seat and to permit the back cushion assembly to recline at a greater angle from the vertical than the rake-adjustable back panel.

Preferably the seat mechanism will be driven by a motor producing high torque at low revolutions, transmitting power to the drive components through a gearbox, in order to effect a smooth operation. All components should be manufactured from suitable materials that are light but robust, and the chassis and frames may be fitted with fairing panels that enclose as far as possible any moving or exposed parts and protect the occupant from access to any cavities created when the mechanism is activated. Cushion assemblies should be upholstered in appropriate materials, which may be flame retardant. All of the various seat components should be able to withstand appropriate industry stress and performance tests.

The seat mechanism should be aligned to permit the functions to be operable, if used within aircraft, within the seat pitch afforded to conventional fixed seats and without impinging to any greater extent than a conventional design upon the personal space of the seats fore and aft of it. The arm rest may be fitted with remote controls for operating television or hi-fi equipment, lighting, calling attendants or other functions and may be contoured and padded on the underside so that when retracted it forms a continuous line with adjacent seat back upholstery. The cavity between adjacent seat cushions may be fitted with a pad that will provide a continuous cushion or lower arm rest when the upper arm rest is retracted. The back of the seat may be fitted with a retractable stowable tray and the rear of the head rest may be fitted with a television or plasma screen. The seat frame may be independent, or connected to adjacent seats in such a way as to provide uninterrupted leg room for the passenger behind, in which case offset floor anchors can mount the assembly of seats into floor mounting tracks. The mechanism should permit the passenger's legs and feet to occupy a space under the seat in front that is not normally generally accessible and the slim design of the seat cushion support should create additional vertical space when the seat mechanism in front is also activated. An additional pivoting or massaging foot support may

improve comfort and circulation by exercising the calf muscle.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 shows a conventional fixed aircraft seat arrangement, indicating minimum seat pitch, personal passenger space and reduced personal passenger space when a seat is reclined to its maximum from its upright position; Figure 2 illustrates the pressure points caused by attempting to lie down or sleep in a conventional fixed seat; Figure 3 shows two seats, one upright, one reclined as far as its rotation stop will allow, with the cantilever seat cushion assemblies mounted in their inclined control tracks, the contoured back cushion assemblies mounted in their slave tracks and the height adjustable head and neck rests mounted on a track in the back cushion; Figure 4 shows both adjacent seats utilising the limited rake-adjustment facility only; Figure 5 shows the cantilever seat assembly on the left partially lowered and forwarded down the inclined control track, the back cushion assembly inclined more than the rake-adjustable back panel and the head and neck rest moved relative to the back cushion; Figure 6 shows the cantilever seat assembly on the left at its fullest lowered and forwarded extent down the inclined control track, the back cushion assembly inclined at a greater angle than the rake-adjustable back panel and the head and neck rest moved relative to the back cushion; Figure 7 illustrates skeletal views of the seat in three different positions; and Figure 8 shows an alternative embodiment of a reclining seat according to the present invention.

A conventional airline seat comprises two vertical side panels or frames, usually with built in arm rests and entertainment controls. The seat is usually fixed to and between these two vertical frames. The back of the seat is usually hinged at its lower end to the rear of the two vertical side panels so that it can be brought to a near vertical position for take off and landing and partially reclined for further comfort during the flight. The seats are

often linked in a bench format and the floor anchor points may be misaligned so that a supporting leg can impinge on the free immediate leg room of the passenger. This seat provides individual or shared side frames with floor aligned offset anchors that do not impinge upon passengers'free leg room.

The seat comprises an assembly of panels, slide, drive and other components, fitted with an upholstered contoured seat cushion, an upholstered contoured back cushion with an integral upholstered head rest and neck support, which when attached to the side fames of the seat and to the back frame and actuated by a drive mechanism, permit the seat and back panels to travel smoothly and progressively in a forward and downward motion relative to the floor and to the fixed side frames in such a way as to move the passenger from an upright sitting position to a reclined position, fully supporting the spine, neck and head yet without affecting the passenger behind.

Referring to the drawings (Figures 3 and 4), the internal seat mechanism is mounted independently in tracks 1 and 2 fitted respectively to, and between, the fixed lower side panels or seat frame 3 and inside the rear shell/frame of the seat back 4. The rear shell of the seat 4 inclines in the normal way for general comfort during the flight with its permitted rake limited by a rotation stop device (not shown). But for sleeping, greater comfort or relieving fatigue, the internal seat mechanism is activated (see Figure 5). The seat cushion 5, mounted on a cantilever deck 6 fitted with pinions and standard bearings 7, with the back cushion 8 mounted on a back panel 9 fitted with slave bearings 10 and attached to the seat by means of a hinge 11, is driven by a motor 12 through a gearbox 13 and is thus permitted to move along the drive slide 1 and the slave slide 2 progressively forward and downward in a smooth action, the seat maintaining its largely horizontal attitude to the cabin floor.

Thus the internal back mechanism of the seat is permitted to recline further than, and inside, the rear shell. A height adjustable neck and head support 14 travels in a vertically aligned independent track 15 mounted centrally within the internal seat back, adaptable for children as well as adults.

CONSTRUCTION The two vertical side frames 3 of the passenger seat and arm rest section are securely mounted onto the cabin floor or anchored into seat location guide tracks that may be built into the floor. The side frames are linked by a rear panel 17 and a front link frame 18 (not shown) to provide dimensional stability and rigidity independent of the internal sliding seat mechanism. In an iteration, the seat sides, rear panel and front link frame may be a cast or moulded entity. The rear shell and side panels 4 of the back rest section are hinged 19 to the seat frame 3 and the armrest 20 is similarly hinged 21 to the seat frame.

Axially aligned guide tracks 1, which in one iteration may be inclined and incorporate a serrated rack, are fixed to the inside faces of the vertical side frames 3. Further axially aligned guide tracks 2, which may or may not be racked, are fixed to the inside side faces of the seat back outer shell 4. Moulded or vacuum formed synthetic fairings (not shown) may be fixed to the frame castings to hide the moving parts and to protect against fingers, limbs or property becoming trapped during operation of the seat mechanism, including the cavity behind the seat back cushion 23 created when the seat mechanism is fully extended, the guide tracks, the motor and the gearbox.

The seat base comprises a flat or contoured cantilever deck or platform 6 which, in one iteration, may be perforated alloy or a synthetic material for minimal weight combined with optimum tensile strength, fixed to, or formed with, two shaped vertical side panel carriers. In an iteration, it may be moulded or cast to a prescribed shape. Carriage plates fitted with concentric and eccentric v-wheels and rollers or pinion wheels 7 connect the seat platform 6 to the guide tracks 1. When assembled, the seat platform and side carriers form a cantilever relative to the inclined guide tracks. To the platform 6 is fixed an appropriate foam or other contoured synthetic cushion 5, upholstered with a resilient material.

The seat back comprises a flat or contoured panel 9, which may, in one iteration, be similarly perforated for lightness combined with rigidity and strength and may or may not be moulded or cast. An appropriate foam or other contoured synthetic cushion 8, upholstered with a resilient material, is fixed to the seat back panel. Rotating carriage plates

fitted with concentric and eccentric v-wheels and rollers 10 are fixed to either side of the upper section of the seat back panel 8 and connect the seat back to the slave guide tracks 2.

A standard head rest 16 may be incorporated or may be separate and may or may not be connected to the top of the seat back cushion 8 by means of a hinge. The assembled seat back and head rest is connected to the rear of the seat platform by means of a hinge 11.

When assembled and driven, the slave guide mechanism permits the back cushion assembly 8 and 9 to move in conjunction with the seat platform 5 and 6, the upper pivot of the back cushion assembly following the axis of the slave track 2 attached to the inclined seat shell 4 and the lower end, connected to the seat platform 6 by means of a hinge 11, moving forward and downward relative to the fixed side frame 3 and the floor.

Into or onto the seat back panel 9 is fixed a further radially aligned slide mechanism 15 to which a specially profiled neck support 14, which may or may not incorporate a contoured head rest, is attached. In operation, this neck and head support 14 can slide independently relative to the seat back cushion assembly 8 and 9 so that it can be located in a position appropriate to the individual passenger, whether child or tall adult and whether or not the seat mechanism is deployed. A retractable tray 22 may be incorporated into the seat back panel 9.

Of preference, the seat mechanism is directly driven by a low voltage motor 12 or other suitable device located beneath, and possibly connected to, the underside of the seat platform 6, operating at low speed and generating high torque, via a reduction gearbox 13 and keyed output shafts (not shown) connecting the motor and gearbox to the pinion wheels 7, which in turn may be secured to the carriage plates by pillow blocks or other device (not shown).

It will be appreciated that in a modification the tracks may be rigid with the back rest and the seat portion while the runners engaging the tracks may be rigid with a base for the seat.

Referring to figure 8, an alternative embodiment of a reclining seat operates in a similar manner to that which is described above, with the exception that here the armrest 20

also moves in conjunction with the seat 5, and a headrest 26 hinged 25 to the seat back panel 9 traverses a dog-legged guide track 2'.

As the seat is reclined, the bearings of the headrest and the upper bearings of the back panel move downwards along an upper section of the dog-legged guide track 2'. This upper section is preferably at an angle of between 80° and 90° relative to a horizontal reference defined by the supporting floor. The most preferred angle is 85°.

As the seat is further reclined the bearings move from an upper section to a lower section of the dog-legged guide track 2'. This lower section is preferably at an angle of between 65° and 75° relative to the above mentioned reference, but is most preferred at an angle of 70°.

Consequently, as the headrest traverses the elbow of the dog-legged guide track, the relative angle between it and the seat back panel becomes less obtuse.

At the same time as the headrest traverses the dog-legged guide track, the lower part of the seat traverses the drive slide 1, and the arm rest 20 moves downwards in conjunction with the seat 5 to a lower position as shown. Preferably, the angle that the drive slide makes with the horizontal reference line is between 33. 5°and 43. 5°. However, in the embodiment shown, the angle is approximately 38. 66°.

Figure 8 also shows tie bars 24 that are employed to separate and/or link adjacent seat frames.