IES81179B2 - A seat - Google Patents

Abstract

A self-inflating cushion comprises a foam core enclosed in an airtight envelope. The airtight envelope is provided with air inlet/outlet valve 4 at a first location and an equalisation valve 6 at a second location. The inlet/outlet valve is operable by a user to cause deflation of the cushion when weight is brought to bear on the cushion ad inflation of the cushion when that weight is removed. The equalisation valve acts as a bleed inlet for slowly admitting air when there is no weight on the cushion and as a pressure relief valve for rapidly exhausting air from the cushion if the pressure difference between the inside and outside of the cushion exceeds a certain value. The inlet/outlet valve may be operated by means of a remote actuator 7.

Description

The present invention relates to a seat and in particular to a seat or seat element for use in long distance travel.

Reduced mobility for passengers, on aircraft or trains, during transit can lead to muscle cramps and tiredness. Additionally, there is a small but nonetheless significant risk of more serious injury due to pooling of blood in and around inactive joints.

To overcome these problems, a number of solutions have been proposed to reduce passenger fatigue and discomfort. Reclining seats afford travellers a greater range of sitting positions and facilitate sleep during the journey. The space available on busses, trains, aircraft and the like however, limits the degree to which the seat may be reclined.

Thus, the passenger must remain seated rather than adopting a prone position and the problems outlined above are therefore alleviated only to a small degree.

Self-inflating cushions located at various points in the seat to mould a passenger’s shape offer a significant advantage over conventional reclining seats. The cushions are formed from open cell resilient foam cores, variously shaped to accommodate a passenger’s back, head, posterior and knees. The foam core is enveloped in an airtight skin with the volume of air in the envelope being controlled by a valve. A traveller on taking the seat operates the valve to dispel air from the cushion so that it correctly moulds their shape. In this way correct posture and optimum support are guaranteed greatly increasing passenger comfort.

Between uses, the cushion slowly re-inflates by drawing air back into through the valve into the resilient foam core so that it is correctly shaped for the next passenger.

Irish Patent Application No. S940900 discloses a self-inflating modular seat insert that operates in this way. While the seat insert described represents a significant improvement over existing designs and correctly identifies some of the shortcomings associated with their use, it does not comprehensively address these problems. For example, the air control mechanism is relatively bulky and complex. This greatly increases production costs and the likelihood of component failure, which significantly limits the range of applications in -2which the cushions may be used. Additionally, the physical size and shape of the unit present designers with unacceptable limitations, as the unit must physically be located in the seat. The weight of the unit can also prove problematic in sensitive applications such as in aircraft where tolerances are critical. Furthermore, safety restrictions to prevent passenger injury in the event of an emergency limit the use of the mechanism described.

Additional problems arise in the use of such systems arising from the need to adjust the seat in transit. Occasionally, the passenger may over deflate the cushion and wish to begin the process again or may wish to change position in the seat and re-mould the seat to the new position. Prior art documents allow for these eventualities, by allowing the user to reopen the air control mechanism to re-inflate the cushion however, the response times for this inflation are unacceptably high. Similarly, while the mechanisms described to reinflate the seats between uses without the need for operator intervention is useful, the lack of adjustability in this response time limits the range of applications for the unit as a whole.

A particular difficulty arises in the use of such seats on board aircraft in the event of a sudden cabin depressurisation. The disparity in pressure inside and outside the envelope causes the insert to expand pushing the passenger against the seat belt before bursting or exploding if the pressure differential is sufficient. A number of solutions have been proposed. In one, the envelope is provided with a weakened portion in a seam, which, would rupture in an emergency to prevent an explosion. This solution is unacceptable in that all seat inserts would then necessitate replacement following the emergency. Other solutions provide an emergency vent on the air control mechanism. While this solution is obviously preferable to the rupturable insert, the location and size of this vent prevent rapid equalisation of pressure between the cabin and the inside of the envelope thereby causing passengers discomfort at an already traumatic time by forcing them albeit for a short time against seatbelts.

There is therefore a need for seat incorporating a seat insert, which will overcome the aforementioned problems. -3Accordingly, there is provided a self inflating seat or seat insert comprising, a compactible resilient open cell foam core and an airtight envelope about the foam core, the envelope having an air inlet or exhaust valve in a first location and an equalisation valve in a second location. There are numerous technical advantages of the current invention over previous attempts to solve the problems associated with inflatable seats and seat inserts. The provision of separate valves in this way the size, weight, cost, and complexity are reduced. This provides a significantly more dependable unit. As the same valve can be used for manual and remote actuation the number of spare parts that need to be carried by maintenance personnel is greatly reduced providing shorter and cheaper services. The reduced complexity also guarantees a more dependable unit. As the valves are smaller and are located at different points on the envelope designers are free position them as necessaiy and need not worry about housing space or the provision of suitable venting chambers.

A further advantage in separating the valves is obtained in response time both in the time taken to re-inflate the insert during normal operation and in the time taken to equalise pressure in the event of an emergency. This is achieved by providing a greater aperture into the envelope. As the valves far less complex that those currently available they can be readily adapted for production using for example injection moulding technologies. This greatly reduces the cost of manufacturing the insert and allows greater freedom in techniques used. The use of moulding further reduces the weight of the unit making it particularly attractive to the aircraft industry where weight concerns are critical.

Preferably, the inlet or exhaust valve is operable to inflate or deflate the envelope and the equalisation valve includes means for rapid equalisation of the pressure between the interior and exterior of the envelope.

Ideally, the inlet or exhaust valve is formed for detachable engagement with a remote actuator.

In one arrangement the inlet or exhaust valve incorporates a valve housing for receiving a valve piston. -4Preferably the piston is spring loaded and has a sealing ring.

In one embodiment the remote actuator incorporates a pivot arm for operating the inlet or exhaust valve.

Preferably the pivot arm is mounted in a pivot housing, the housing in turn defining a cable engagement means and being formed for snap fit engagement with the inlet or exhaust valve.

In a particularly preferred embodiment the actuator includes an air regulation cap for mounting on the pivot housing to control airflow through the inlet or exhaust valve.

Preferably the pressure equalisation valve comprises a decompression housing formed for receiving a pressure release mechanism and defining an air conduit to rapidly vent air from the envelope.

In one arrangement the pressure release mechanism is also formed for timed equalisation of pressure between the interior and exterior of the envelope.

Ideally, the timed period for equalisation may be varied.

The invention will now be described with reference to the accompanying drawings, which show, by way of example only, some embodiments of a seat insert in which: Fig. 1 is a front view of a seat insert in accordance with the invention; Fig. 2 is a side view of the seat inset of Fig. 1; Fig 3. is a front view of an alternative seat insert in accordance with the invention; Fig. 4 is a side view of the seat insert of Fig. 3; -5Fig 5 is a section view of an assembled air inlet valve and actuator forming part of the seat insert of Figs. 1 and 2; Figs 6 to 14 show various views of component parts of the air inlet valve and 5 actuator of Fig. 5; Fig. 15 is a section view of a pressure equalisation valve forming part of the seat insert of Figs 1 to 4; and Figs 16 to 19 show various views of component parts of the decompression valve of Fig. 15.

Referring to the drawings and initially to Figs. 1 and 2 there is shown a seat insert in accordance with the invention indicated generally by the reference numeral 1. The seat insert 1 is formed for use in vehicle seats where passengers or staff will remain seated for a considerable period of time such as on board busses, trains or aircraft. To overcome the physical stress and fatigue associated with such journeys, the insert 1 is deflated to mould the passenger’s body. The insert 1 is self-inflating and has a compactible resilient open cell foam core (not shown) shaped to accommodate a particular portion of a traveller’s body. The shape of the foam may be easily varied for insertion into, inter alia headrests, lumber supports, seat cushions and knee backs.

The shaped foam is sealed in an airtight envelope 2 having two apertures, a first aperture 3 formed for receiving an air inlet or exhaust valve 4 and a second aperture 5 formed for receiving a pressure equalisation valve 6. The inlet or exhaust valve 4 is operable by the passenger to inflate or deflate the envelope 2 and the equalisation valve 6 is formed to very rapidly equalise the pressure between the interior and exterior of the envelope 2. In this embodiment the air inlet or exhaust valve 4 is operated by the passenger using a remote actuator 7 detachably mounted on the air inlet or exhaust valve 4.

Referring now to Figs. 3 and 4 there is shown an alternative seat insert in accordance with the invention indicated generally by the reference numeral 100. In this embodiment of the -6current invention the air inlet or exhaust valve 4 is operated directly by the passenger to inflate or deflate the insert 100. It is an important feature of the current invention that the air inlet or exhaust valve 4 for both embodiments is formed in the same way. This greatly reduces the number of spare components that repair or service personnel are required to carry and furthermore reduces complexity and costs in production. It is a further feature of the invention that by separating the functions of air inlet / exhaust and pressure equalisation the speed at which the insert may be inflated or deflated is greatly improved. Similarly a failure of a component in one valve does not require replacement of the entire unit. Additionally, the equalisation valve 6 may be easily adjusted to provide a more appropriate non-emergency re-inflation time.

In more detail and referring now to Figs. 5 to 15 the air inlet or exhaust valve 4 is shown with the remote actuator 7 attached. It will be understood that the manner of construction of the exhaust valve 4 is independent of the remote actuator 7 but that the relatively construction of both elements represents a significant improvement over currently available devices.

The air inlet or exhaust valve 4 has a valve housing 41 for receiving a piston 42 having a head portion 43 and a sealing portion 44. The Piston 42 prior to insertion has an O ring 46 affixed to the sealing portion 44 and a helical spring 45 mounted around the piston 42. The spring 45 biases the air inlet or exhaust valve 4 into a closed position with the 0 ring 43 sealing the housing 41.

In use, the housing 41 is fitted in an airtight manner into the first aperture 3 with only the head portion 43 exposed from the envelope 2. To deflate the envelope 2 the passenger depresses the exposed head portion 2 moving the O ring 46 away from the housing 41 and air passes through the air inlet or exhaust valve 4. When sufficient air has been evacuated the passenger releases the head portion 41 and the spring 45 moves the piston 42 back into the sealed position with the 0 ring against the housing 41.

In certain arrangements it may be necessary to extend the head 41 using an interference fit button 47 inserted into a cavity 48 of the piston 42. For example, if the insert is located in 1 ........... ιι___ -7from the edge of a seat then is may be desirable to use this arrangement. The button 47 may optionally have a tapered shoulder 49 to engage with the housing 41 to keep the valve 4 open when the passengers finger is remove. This is particularly useful where it is desired to fully deflate the insert leaving both hands free for rolling.

Referring now in particular to Figs. 5 and Figs. 11 to 16 the remote actuator 7 is provided in this case by a cable controlled operator using a pivot arm 71. The pivot arm 71 has a mounting shaft 72a an operating face 73 and a cable-receiving groove 74 for locating a control cable 75. The pivot arm 71 is pivotally mounted in a pivot housing 72 and a cable with a nut adjuster 76 is introduced into the housing 72 through an opening 73. The cable 75 is engaged with the pivot arm 71 by guiding the cable 75 into the groove 74. An air regulation cap 77 is then rotatably mounted on the housing 72. The regulation cap 77 defines a cable-receiving groove 78 and rotation of the cap 77 on the housing 72 limits the amount of air which can pass through the valve 4 in a given time period.

In use the passenger operates a conventional cable control to with draw the cable 75. This movement pivots the pivot arm 71 in the housing 72 until the operating face 73 contacts the head portion 43 of the valve 4. Further operation depresses the piston 42 to allow air through the valve 4. Releasing the tension allows the valve 4 to return to the rest position.

As air passes through the rotation cap 77 the volume of air which can pass through the valve 4 in a given time is limited by the size of the aperture around the cable 75 defined by the groove 78.

In more detail and referring now to Figs. 16 to 19 the pressure equalisation valve 6 is shown. The pressure equalisation valve 6 has a decompression housing 60 formed for receiving a pressure release mechanism and defining internal air conduits 69 to rapidly vent air from the envelope 2. The pressure release mechanism is provided in this case, by an O ring 61, a support disk 62, a decompression membrane 63, a biasing spring 64, and a retaining ring 65. The 0 ring 61 is mounted in an internal groove (not shown) of the housing 60 to surround and inlet opening 66. The decompression membrane 63 is then mounted in the housing on top of the 0 ring 61. The decompression membrane 63 has small hole at the centre to allow the insert to gradually re-inflate between used. The -8support disk 62 is then mounted on the membrane 63 within the housing 60. The disk 62 also has a small hole offset from and non-coincident with the membrane hole for the same putpose. The disk 62 and membrane 63 are biased against the ring 61 with the spring 64, which in turn is held in place, by the retaining ring 65 snap fitted into the housing 60.

In use when the external envelope pressure is much less than the internal envelope pressure the spring 64 is biased away from the ring 61 allowing air from the insert though the housing 60. This is achieved much more quickly than has previously been possible because of the internal housing conduits 69 .

It will be understood that while the invention described herein has referred extensively to the use of the envelope as a seat insert that it may equally be provided as a portable cushion or mattress for use in a variety of similar applications.

It will of course be understood that the invention is not limited to the specific details as herein described, which are given by way of example only, and that various alterations and modifications may be made without departing from the scope of the invention.

Claims (5)

1. A self inflating seat insert comprising, a compactible resilient open cell foam core and an airtight envelope about the foam core, the envelope having a gas valve in a first location and an equalisation valve in a second location away from the air valve.

2. A self inflating seat insert as claimed in claim 1 in which the gas valve is operable to control gas pressure in the envelope and the equalisation valve includes means for rapid equalisation of the pressure between the interior and exterior of the envelope, and optionally in which:the gas valve incorporates a valve housing for receiving a valve piston, the piston optionally being spring loaded and having a sealing ring; and the gas valve is formed for detachable engagement with a remote actuator, the remote actuator optionally incorporating a pivot arm for operating the gas valve, the pivot arm being optionally mounted in a pivot housing, the housing in turn defining a cable engagement means and being formed for snap fit engagement with the gas valve, the actuator optionally includes an air regulation cap for mounting on the pivot housing to control airflow through the gas valve.

3. A self inflating seat insert as claimed in any preceding claim in which the pressure equalisation valve comprises a decompression housing formed for receiving a pressure release mechanism and defining an air conduit to rapidly vent air from the envelope.

4. A self inflating seat insert as claimed in claim 3 in which the pressure release mechanism is also formed for controlled automatic equalisation of pressure between the interior and exterior of the envelope. -10

5. A seat or self inflating seat insert substantially as herein described with reference to and as shown in the accompanying drawings.