The subject invention relates to air treatment in passenger vehicles, such, for example, as passenger railway vehicles, coaches, buses, ferries, hydrofoils, hovercraft and aircraft. The subject invention finds very advantageous application in respect to passenger cabins of aircraft.

The subject invention may be advantageously used in conjunction with that of PCT/GB 95/02215 filed on 20 September 1995.

The subject invention provides in combination, a vehicle seat, air inlet means and air treatment means, which air treatment means comprises an air induction means and air filtration means, said air inlet means being located in the vicinity of the distal end of an arm rest of said seat and said air inlet means being air flow communicable with said air treatment means.

As used herein, the term "arm rest" should be taken to include an actual arm rest physically part of the seat, an arm rest with respect to the seat but not physically part of the seat, for example an arm rest on the inside of a car door, or a notional arm rest. As used herein, the term "notional arm rest" has reference to the case in which to one side of the seat, the seat is absent an arm and refers specifically to the location at which, were an arm present, said arm would be positioned. An example is the location on a wall of a vehicle, in which vehicle the passenger seat is

located, where an arm rest would be positioned on the wall if an arm rest were associated with the seat.

The air inlet means may be moveable between first and second positions with respect to the arm rest, which positions correspond respectively with operable and inoperable conditions of the air treatment means. Thus when the air inlet means is in the first position thereof, air can be drawn through the air inlet means from the environment thereabouts, whereas when the air inlet means is in the second position thereof air cannot be drawn therethrough. It may be that passage means of the air inlet means is open when the air inlet means is in the first position, but that when the air inlet means is moved to the second position, obturation means is brought into register with the passage means, whereby the passage means is obturated. Alternatively, the passage means may comprise valve means being operable to place the passage means in an open condition when the air inlet is in the first position and the valve means being operable to place the passage means in a closed condition when the air inlet is in the second position.

If the air inlet means is moveable between first and second positions, the movement therebetween may be linear movement or angular movement.

Instead of the air inlet means being moveable, obturation means may be moveable between first and second positions thereof, whereby passage means of the air inlet means is open when the obturation means is in the first

position, this corresponding to the operable condition of the air treatment means, and the passage means is obturated when the obturation means has been moved to the second position, this corresponding to the inoperable condition of the air treatment means. For example, the obturation means may be provided by a slidable element which is bodily movable over the air inlet, which air inlet is provided as an opening in the arm rest.

Alternatively, the passage means may comprise valve means, the valve means being placeable in an open condition when the obturation means is in the first position thereof, and being placeable in a closed condition when the obturation means is in the second position thereof.

In a yet further arrangement the air inlet means is secured relative to the arm rest and valve means in passage means of the air inlet means is placeable in an open condition thereof, this corresponding to an operable condition of the air treatment means, and is placeable in a closed condition thereof, this corresponding to an inoperable condition of the air treatment means. The air inlet may be fixedly secured relative to the arm rest. The valve means in this arrangement may be associated with valve actuation means and gas detection means, whereby, when a designated gas, carbon dioxide for example, is detected by the detection means to be present in the vicinity of the passenger seat at a concentration above a threshold level concentration, a signal is transmitted from the detection means to the valve actuation means, whereupon the valve

means is placed by the actuation means in an open condition thereof.

In all of the above mentioned arrangements of the subject invention, it is envisaged that the air treatment means may be operated in response to a sensor detecting whether the passage is blocked or not blocked, or in response to gas detection means detecting a concentration of a designated gas above a threshold level. Alternatively, the air treatment means may be operated by a switch associated with the seat, which switch is operable by a person using the seat, or the air treatment means may be controlled by a central switch mechanism. The central switch mechanism may be remote the seat. Preferably, if gas detection means are used the detector is in the vicinity of the seat.

Alternatively, the air inlet housing of the air inlet means may be removably securable with respect to the arm rest. In this case the seat may be used as a seat for smokers or a seat for non-smokers. If the seat is required to be used as a seat for non-smokers, an obturation device may be provided to seal the passage means of the air inlet means. Alternatively, the passage means may be automatically sealed off, by valve means for example, when the air inlet housing is removed. If the air inlet housing is secured with respect to the arm rest, i.e. the seat is required to be used as a seat for smokers, the air treatment means may be made operable by moving the air inlet means between a first position corresponding to an operable condition of the

air treatment means, and the air treatment means may be made inoperable by moving the air inlet means to a second position corresponding to an inoperable condition of the air treatment means. Alternatively, valve means may be provided the connecting passage placeable in an open condition and in a closed condition thereof. The valve means may operate in response to gas detection means. Alternatively, the air inlet means may be always in air flow communication with the air treatment means and the air treatment means may be made operable by a central switch mechanism.

The passenger seat may comprise, at an upper location of the arm rest, a cigarette ash receptacle fitted with a lid, movement of the lid to a position permitting access to the receptacle causing the air inlet means to be moved to the first position thereof and movement of the lid to a receptacle closure position causing the air inlet means to be moved to the second position thereof. Alternatively, and in a case in which the air inlet means is fixedly secured relative of the arm rest, movement of the lid to the access permitting position causes valve means in passage means of the air inlet means to be placed in an open condition and movement of the lid to the closure position causes the valve means to be placed in a closed condition.

Advantageously, the air treatment means is in combination with a group, e.g. a row, of passenger seats, and in respect of each of the seats of the row there is an air inlet means. For a given seat, one air inlet means may be disposed at one side of the seat, another air inlet

means being disposed to the other side of the seat. It is also advantageous that the air induction means is a single air induction means operable to cause air-flow via all of the air inlet means of all of the seats of the row. It is further advantageous that the filtration means is a single filtration means common to all of the seats of the row.

The air induction means and the air filtration means may be assembled together as a single air treatment unit. The air inlet means too may form part of such unit. A separate unit may be associated with each seat of a plurality of seats, or a plurality of seats may be served by a single unit.

If the seat of a combination according to the subject invention is located in an aircraft cabin, air outlet means of the air treatment means may be located relatively of cabin air withdrawal means of the cabin ventilation system such that the air issuing from the outlet means is drawn from the cabin via the withdrawal means. Also, the air filtration means of the air treatment means may be provided by air filtration means of the cabin ventilation system. Furthermore, the air induction means of the air treatment means may be provided by air induction means of the cabin ventilation system.

In order that the subject invention may be clearly understood and readily carried into effect, reference will now be made, by way of example, to the diagrammatic drawings hereof, in which:-

Figure 1 shows two aircraft passenger seats installed in an aircraft passenger cabin;

Figure 2 shows, in sectional view, a forward portion of an arm rest of one of the seats of Figure 1;

Figure 3 shows a view of the arm rest of Figure 2 as viewed in the direction of arrow A; and

Figure 4 shows the forward portion of an arm rest of an alternative embodiment of the subject invention.

In Figure 1 the passenger seats are designated by reference numerals l and 2. The seats l and 2 are secured to aircraft cabin floor 3, with seat 1 being positioned directly behind seat 2. Reference numeral 4 designates a transverse cabin bulkhead.

The seats 1, 2 comprise right-hand side arm rests 5 and 6 respectively. At the forward, i.e. distal, end of the arms 5,6 and at an upper location thereof are pivotally mounted air inlets 7, 7' respectively. By way of the pivotal mounting thereof each of the air inlets 7, 7' can be moved between a first position, in which the inlet projects from the arm rest, and a second, retracted position in which the inlet is located within the arm rest. The air inlet 7 mounted at the distal end of arm rest 5 of seat 1 is shown in the first, projecting position thereof. The air inlet 7' mounted at the arm rest 6 of seat 2 is in the second, retracted position thereof.

The air inlet 7, which is formed as a perforated sheet metal housing, is pivotally mounted within the arm rest 5 at location 8 of a block 9. Mounted beneath the block 9 is a

valve 10. Air inlet means 7 is air flow communicable with air treatment means 12 by means of pipe 11. When the valve 10 is in an open condition, the interior of air inlet 7 is in air-flow communication, via the block 9 and a pipe 11, with air treatment means 12.

When the air inlet 7 is moved from the retracted to the projecting position a rear portion of the inlet 7 contacts a microswitch 13, which contact causes an electrical signal to be transmitted via a line 14 to electrical actuation means of the valve 10, whereby the valve 10 is placed in the open condition thereof. Air from the environment thereabouts of the inlet 7 is caused, under action of the air induction means of the aforesaid air treatment means, to be extracted through the perforations of the inlet 7. Thus if a person seated in seat 1 is holding a lit cigarette in the vicinity of the inlet 7, air, together with sidestream smoke from the cigarette, will be drawn through the inlet 7 and then via the pipe 11 to the air treatment means.

Figure 4 shows an arm rest 15 and attached to the distal end of the arm rest 15, a transition block 16. Securedly attached to the transition block 16 is a mounting block 17. The arm rest 15 and the blocks 16 and 17 are arranged in a substantially linear relationship and comprise a bore 18 extending jointly therethrough, which bore 18 provides passage means connecting an air inlet 19 and air treatment means 20, whereby the air inlet 15 is air flow communicable with the air treatment means 20. The air inlet 19, which comprises a hollow body 21, is provided with

openings in vertical face 22 and the base 23 thereof. The opening in vertical face 22 is covered by a grille. The air inlet 19 is securedly attached to a plate 24, which plate 24 comprises a spigot 25 and a central opening 26 extending through the entire thickness of the plate 24 including the spigot 25. The spigot 25 of the plate 24 is received, as a sealable fit, in the bore 18 in block 17. According to this embodiment of the invention, the air inlet 19 is always air flow communicable with the air treatment means 20, and air treatment means 20 is made operable by means of a switch mechanism (not shown) .

In operation of that embodiment of the invention depicted in Figure 4, with a smouldering cigarette in the vicinity of the distal end of the arm rest 15 and when the air treatment means 20 is operable, air, together with sidestream smoke from the cigarette, will be drawn, by the action of induction fan 28 of the air treatment means 20, through the opening in face 22 and into the hollow body 21 of air inlet 19 and thence via the opening 26 and along the bore 18 and connecting bore 18' to the air treatment means 20, which connecting bore 18' connects bore 18 with the inlet of air treatment means 20. The air, together with the sidestream smoke, then passes through filtration means 27 and filtered air passes out of the air treatment means 20 via the air outlet (not shown) of an air treatment means.