IES64486B2 - Self-inflating modular seat insert - Google Patents

Abstract

A self-inflating seat or modular seat insert or element comprises a compactible resilient open cell foam core, an airtight outer skin surrounding the foam core, and a valve arrangement operable to allow airflow into and out of the airtight outer skin. The valve arrangement includes an automatic slow air bleed back valve which operates automatically, in the absence of passenger weight against the seat or seat insert or element, to effect slow self-inflation. The outer skin is made of relatively flexible material and the inner surface of the outer skin is bonded to the outer surface of the resilient open cell foam core so that the outer skin adopts the shape of the foam core and so that substantially no free air spaces exist within the outer skin.

Description

Self-inflating cushions have recently been introduced for the pilot seats in long haul commercial aircraft. A cushion is placed on the pilot seat in the lumbar (lower back) region. The cushion comprises a resilient open cell foam core and an airtight outer skin surrounding the foam core. The open cell foam core is of the general size and shape of a conventional household seat cushion. The outer skin consists of a polyvinylchloride (PVC) cover. An air hose pipe leads from the cushion to the arm-rest of the pilot seat and a manually operable valve is provided at the free end (the pilot seat arm-rest end) of the hose pipe. Reflation of a compacted (deflated) cushion is effected by opening the valve. The compacted open cell foam, which is of resilient material expands and sucks air through the valve so that the cushion automatically reflates. Deflation is effected by opening the valve and at the same time squeezing the cushion so as to drive air 364486 - 2 out. The self-inflating cushions have found favour with pilots travelling on long journeys.

Nevertheless, the self-inflating cushions suffer from certain disadvantages which mitigate against wider use, for example use on passenger seats in aircraft, trains or other forms of mass transportation, or use in vehicles. The response time (time to self-inflate) is relatively slow due to the thickness of the PVC skin. The hose and valve arrangement is quite large. The valve is located at the arm-rest so that the air exhausts at this point. The outer skin does not hold air well. The joint between the cushion and the rest of the seat (made of high density aircraft seat foam) may be uncomfortable. If used in mass transportation, considerable cost and inconvenience would arise if attendants on a train or aircraft were required to move along the narrow aisles in order to carry out the additional task of ensuring that the cushion on each seat was inflated to the correct degree. This would have to be done between flights in order to ensure that business class passengers would find their seats fully inflated when initially taking their seats. This might have to be done at the start of a flight or during a flight for travellers who may require assistance, for example infrequent travellers or invalid travellers.

If used in vehicles, the slow response time might be unacceptable to the driver who is used to being able to make instant use of his vehicle.

Object and Summary of the Invention An object of the present invention is to provide an improved self-inflating seat or modular seat insert, in particular a self-inflating modular seat insert with a better response time.

In one aspect the invention provides a self-inflating seat or modular seat insert or element comprising a compactible resilient open cell foam core, an airtight outer skin surrounding the foam core, and a valve arrangement operable to allow airflow into and out of the airtight outer skin, characterised in that the valve arrangement includes automatic slow air bleed back means which operates automatically, in the absence of passenger weight against the seat or seat insert or element, to effect slow self-inflation.

Preferably the valve arrangement comprises a valve located at a seat back and including biassing means for biassing the valve to the closed position, a passenger operated control means for mounting on a seat arm-rest, and an operating cable between the control means and the valve operable to move the valve against the action of the biassing means to the open position.

Preferably the slow bleed back valve means comprises a flexible diaphragm with an air hole and a diaphragm seat with an air passage, the air hole and air passage being out of mutual alignment.

In another aspect the invention provides a valve arrangement in accordance with either of the foregoing paragraphs for use with a self-inflating seat or modular seat insert or element or any other self-inflating article.

In another aspect the invention provides a self-inflating seat or modular seat insert or element comprising a compactible resilient open cell foam core, an airtight outer skin surrounding the foam core, and a valve arrangement operable to allow airflow into and out of the airtight outer skin, characterised in that the outer skin is made of relatively flexible material and the inner surface of the outer skin is bonded to the outer surface of the resilient open cell foam core so that the outer skin adopts the shape of the foam core and so that substantially no free air spaces exist within the outer skin.

A self-inflating seat or modular seat insert or element of complex shape may be constructed which can be deflated by external pressure anywhere on the outer skin.

Preferably the inner core is made of low density open cell polyurethane foam, and the outer skin is made of synthetic tafetta, and the inner core and outer skin are heat bonded to one another.

The choice of synthetic tafetta for example nylon tafetta or polyester tafetta as the outer skin represents a substantial advantage over the use of polyvinylchloride. The latter is incapable of bonding to polyurethane foam. The latter is also quite stiff. Furthermore, - 4 the latter does not have the same air holding capability as synthetic tafetta.

Preferably the compactible resilient open cell foam core includes one or more regions of harder less compactible foam.

Brief Description of the Drawings The invention will now be described more particularly with reference to the accompanying drawings which show, by way of example only, one construction of self-inflating aircraft seat back according to the invention. In the drawings: Figure 1 is a perspective view of the seat back; Figure 2A, 2B, 2C and 20 show the manner in which the seat back (without valve arrangement) is assembled; Figure 3 is an exploded perspective view of the valve arrangement; and Figures 4A, 4B, 4C, 5A, 5B, 5C, 6A,6B, 7A, 7B and 8 illustrate various views of the various components of the valve arrangement.

Description of Preferred Embodiment Referring initially to Figure 1, a seat back generally designated 1 is provided at a rear corner thereof with a valve housing 2 and a cable 3 leads to a button 4 operable by a passenger. The cable 3 is of the type conventionally used in a passenger aircraft seat to allow a passenger to control the rake of the seat. The button 4 is mounted on the arm-rest (not shown) of the passenger seat along side or opposite the other controls (not shown).

Referring now to Figures 2Af 2B, 2C and 2D, the seat back 1 comprises a foam core 5 contained within a nylon tafetta bag 6. Figure 2A shows the core 5 only. The core 5 is a composite structure, comprising a central core element 5a made of resilient, compactible - 5 open cell foam, and two end core elements 5b, 5c made of harder, less compactible foam. All of the core 5 is made of a composite of polyurethane low density open cell foam and graphite impregnated (for fire retardant purposes) high density open cell foam, and the elements of different texture are bonded seamlessly to one another to form the composite core 5. It will be noted that the composite core 5 has a contoured shape, suitable for use as a seat back. Figure 2B shows the core being inserted into the nylon tafetta bag 6. Figure 2C shows the core 5 contained within the bag 6, and at this stage in the assembly procedure heat is applied to the seat back 1 to bond the inner surface of the nylon tafetta bag 6 to the outer surface of the core 5, and to heat seal the bag 6. As a result of this stage in the assembly procedure, the seat back 1 comprises a core 5 which is flexible due to the open cell resilient structure of the central core element 5a, and which may therefore adopt different shapes, and an outer skin (the bag 6) which is bonded to the core 5 so that the outer skin adopts whatever shape is adopted by the core 5. In particular it will be appreciated that there are no dead spaces within the bag 6, that is to say no spaces between the bag 6 and the core 5. Figure 20 shows the completed seat back 1, sealed and provided with an airflow conduit 7.

The use of nylon tafetta has many advantages. Nylon tafetta is extremely flexible, and flexes easily with the changes in shape of the core 5. Nylon tafetta provides good airholding.

The use of the seat back 1 by a passenger will now be described.

It will be assumed that when the passenger sits down the seat back 1 is fully inflated. If the passenger finds the fully inflated seat back 1 comfortable, then no action need be taken by the passenger. However, if the passenger finds the fully inflated seat back 1 to be uncomfortable, the passenger may allow some or all of the air to be released. Deflation is achieved by pressing on the button 4, while continuing to rest against the seat back 1. The seat back 1 deflates for as long as pressure is maintained on the button 4. Once the seat back 1 has reached the desired state of deflation, the passenger releases the pressure on the button 4. If the passenger over-deflates the seat back 1, or if at a later stage the passenger requires a higher level of inflation of the seat back 1, then reflation is effected by - 6 again pressing the button 4, but this time the passenger leans forward so as to remove his weight from the seat back 1.

The arrangement of bonding the inner surface of the outer skin 6 to the outer surface of the core 5 is particularly advantageous. There are no free spaces or dead spaces within the seat back 1. As a result, once the passenger leans back against any part of the seat back 1, irrespective of the shape of the passenger's back, or the shape of the seat back 1, the pressure applied by the passenger's weight is communicated throughout the seat back 1. Furthermore, any such pressure by the passenger immediately elevates the pressure within the seat back 1 to a pressure higher than the ambient pressure. As a result, once button 4 is depressed, deflation takes place quickly and predictably, with absolutely no effort required on the part of the passenger other than to lean back. Similarly, with reflation, because there are no free spaces or dead spaces, the internal pressure within the seat back 1 is communicated throughout the interior thereof, and once button 4 is depressed, air is sucked in. Thus the seat back reflates in a relatively quick and predictable manner. The passenger controlled operations of deflation and reflation occur relatively quickly, within a matter of ten to twenty seconds.

When the passenger leaves the aircraft, and assuming that the seat back 1 was partially deflated at the time of departure, then the seat back 1 automatically reflates slowly, so that after a period of time has elapsed, for example half an hour, the seat back 1 will have fully reflated. Thus the next arriving passenger will find the seat back 1 in the fully inflated condition, but is will not have been necessary for any attendant to ensure that reflation has taken place.

Referring now to Figure 3, the valve arrangement for passenger controlled deflation and reflation will now be described. The valve arrangement comprises a square section elongate valve housing 2, including a bore 11 extending axially along the housing 2, a projecting nozzle 12, and an aperture 13. A slide member 14 is slidably moveable along the bore 11 between a first (closed) position and a second (open) position. In the closed position the domed head 14a of the slide member 14 is located between the nozzle 12 and the aperture 13 and - 7 sealingly engages under the action of spring 15 against collar 16 located in the bore 11, thereby preventing airflow between the nozzle 12 and the aperture 13. In the open position the slide member 14 is located further to the right as seen in Figure 3, the head 14a of the slide member 14 is located between the aperture 13 and the right hand end of the housing 2 allowing uninterrupted airflow along the bore 11 between the aperture 13 and the nozzle 12. Slide member 14 includes a cable anchor recess 14b for receiving an anchor or spud 3a at the end of the cable 3 for pulling the slide member 14 to the right as shown in Figure 3 against the biassing action of the spring 15 to the open position. A plug 17 is provided for the right hand end of the bore 11. Plug 17 is held in position by means of a circlip 18 located within bore 11 near the right hand end thereof. Plug 17 includes a circumferential groove 17a which is a snap fit in the circlip 18. Plug 1Z includes an end face 17b against which one end of the spring 15 is seated, the other end of the spring 15 being seated against the head 14a of the slide member 14. Plug 17 includes an axial bore 17c for slidingly receiving the shank 14c of the slide member 14. Finally, plug 17 includes a central aperture 17d not shown in Figure 3 through which cable 3 is guided from the interior of the valve housing 2 to the exterior thereof.

The valve arrangement for passenger controlled deflation and reflation is installed by connecting the nozzle 12 of the valve housing 2 to the conduit 7 of the seat back' 1, while leaving the aperture 13 exposed to ambient air and mounting the button 4 on the passenger seat arm-rest.

In operation, normally the slide member 14 is in the closed position. However, if the button 4 is operated to pull the cable 3, the slide member 14 moves against the biassing action of the spring 15 to the open position, and airflow may take place in either direction along the airflow path from the interior of the seat back 1, through conduit 7, nozzle 12, bore 11 and aperture 13 to atmosphere or vice versa. If the weight of a passenger bears on the seat back 1, air is driven from the interior of the seat back 1 out to the atmosphere. If the passenger leans forward so that there is no weight on the seat back 1, and if the resilient open cell structure 5 is partly compacted, then - 8 the latter will expand, drawing air in the opposite direction along the flowpath from the atmosphere into the seat back 1.

Referring now to the left hand end of Figure 3, the valve arrangement for automatic slow reflation will now be described. A washer 20, a diaphragm 21 and a plug 22 are provided at the left hand end of the bore 11. It will be seen that the diaphragm 21 includes an eccentric air hole 23. The plug 22 includes a central air hole 24. It will be seen that the right hand face of the diaphragm 21 is subject to the air pressure prevailing in the interior of the seat cushion 1 communicated through conduit 7, nozzle 12 and bore 11. In the event of outward pressure the diaphragm 21 flexes outwardly, that is to say to the left as seen in Figure 3. The diaphragm 21 seats against the plug 22. Because the eccentric air hole 23 and the central air hole 24 are not in register, no outward airflow takes place. However, in the event of inward pressure (i.e. the compacted open cell foam core 5 tending to expand after removal of a passenger's weight), the diaphragm 21 flexes to the right as seen in Figure 3, that is to say away from the plug 22, and air can then flow through the central air hole 24 in the plug 22, through the gap between the plug 22 and diaphragm 21, and through the eccentric hole 23 in the diaphragm 21. The eccentric hole 21 is quite small and permits only a small flow of air.

Referring now to the remaining Figures; Figure 4A Figure 4B Figure 4C Figure 5A Figure 5B Figure 5C is a side elevation of the valve housing 2; is an end elevation thereof from the right hand end; is an end elevation thereof from the left hand end; is a top plan view of the slide member 14; is a side elevation thereof; is an end elevation thereof from the left hand end; Figure 6A is a side elevation of the plug 17; - 9 Figure 5B is an end elevation thereof from the right hand end; Figure 7A is a side elevation of the circlip 18; Figure 7B is an end elevation thereof from the left hand end; and Figure 8 is a side elevation of the valve housing 2 shown partially cut away to reveal the slide member 14 and plug 17.

In a second embodiment (not shown) the foam core may be provided with a pattern of holes, thereby reducing the overall weight and also reducing the resilience.

The invention has been described by way of example with reference to an aircraft seat. It will however be appreciated that the invention may be used for many other purposes, for example in a vehicle seat, bed, or any other support for the lumbar region.

Claims (5)

1. A self-inflating seat or modular seat insert or element comprising a compactible resilient open cell foam core, an airtight outer skin 5 surrounding the foam core, and a valve arrangement operable to allow airflow into and out of the airtight outer skin, characterised in that the valve arrangement includes automatic slow air bleed back means which operates automatically, in the absence of passenger weight against the seat or seat insert or element, to effect slow 10 self-inflation.

2. A self-inflating seat or modular seat insert or element according to claim 1 in which the valve arrangement comprises a valve located at a seat back and including biassing means for biassing the valve to the 15 closed position, a passenger operated control means for mounting on a seat arm-rest, and an operating cable between the control means and the valve operable to move the valve against the action of the biassing means to the open position. 20

3. A self-inflating seat or modular seat insert or element according to claim 1 or claim 2 in which the slow bleed back valve means comprises a flexible diaphragm with an air hole and a diaphragm seat with an air passage, the air hole and air passage being out of mutual alignment.

4. A self-inflating seat or modular seat insert or element comprising a compactible resilient open cell foam core, an airtight outer skin surrounding the foam core, and a valve arrangement operable to allow airflow into and out of the airtight outer skin, characterised 30 in that the outer skin is made of relatively flexible material and the inner surface of the outer skin is bonded to the outer surface of the resilient open cell foam core so that the outer skin adopts the shape of the foam core and so that substantially no free air spaces exist within the outer skin.

5. A self-inflating seat or modular seat insert or element and/or valve arrangement substantially as hereinbefore described with reference to and as shown in the accompanying drawings. . \