T 1944/07 30-06-2009

1. Regulations require that rest areas be provided for aircraft crew members on long haul flights. In order to minimise the economic penalty of providing such rest areas they may be provided in the crown of the aircraft, above the passenger cabin. The patent relates to a system for emergency exit from such an upper level of accommodation into the passenger cabin. The system comprises a slide the undersurface of which when the slide is raised forms a continuation of the ceiling in the passenger cabin, whereby the one component fulfils two functions.

Late filed evidence

2. In accordance with Article 12(4) RPBA everything presented by an appellant in its notice of appeal and statement of grounds of appeal is to be taken into account "without prejudice to the power of the Board to hold inadmissible … evidence which could have been presented … in first instance proceedings … ." All of M11, M14 and M15 were filed by the appellant as evidence relevant to claim 1 according to the main request and therefore in its form as granted. Although the appellant argues that M14, M15 were filed in response to an interpretation of claim 1 by the board, it is clear from the opposition procedure that the appellant had been aware of the possibility to interpret the claim in different ways and therefore could have filed M14, M15 already in the first instance proceedings. The appellant offers no excuse for the late filing of M11. The board finds all of M11, M14 and M15 prima facie of no relevance and under these circumstances it exercises its discretion and disregards them (Article 114(2) EPC 1973).

Main request

Interpretation of claim 1

3. Claim 1 specifies "an emergency escape system in an aircraft … said escape system comprising an exit slide …". The appellant argues with reference to the Guidelines that this wording is unclear and permits the claim to be interpreted as defining a slide merely suitable for emergency use in an aircraft whereby further features in the claim are not limiting. However, the wording of the claim must be considered as a whole and the entire remainder of the claim specifies either features of the aircraft or a relationship between the slide and those features. In the board's judgement the subject-matter of claim 1 clearly is a combination of at least those features of an aircraft which are mentioned in the claim, namely a main passenger cabin having a ceiling and an overhead rest area above the cabin, and an escape slide accessible from the rest area, having an undersurface forming a portion of the ceiling and being movable between a closed position in which it forms a continuation of the ceiling and an open position in which it provides egress from the rest area to the cabin. The section of the Guidelines to which the appellant refers (C-III, 4.15 in the version of December 2007) advises examiners to avoid the formulation used in present claim 1 but gives no guidance relevant to the correct interpretation of the present claim.

Novelty

4. M4 relates to stairs which permit access between an upper and a lower deck in an aircraft. The description acknowledges that such devices were already known but suffered the disadvantage that they caused an obstruction such that they could not be provided in the region of an emergency exit from the lower deck. The solution according to the embodiment of figure 7 of M4 is a staircase which is pivotably connected at its upper end to the ceiling of the lower deck. In the event of an emergency the staircase is pivoted upwards in order to render the lower deck free of obstruction. An additional feature is that the treads (numbered 2 to 7) of the staircase may be pivoted relative to the stringers into a second position in such a way that when the stairs are in the raised position they form a closure to prevent passage of smoke.

4.1 The appellant argues that the stairs when in their lowered position but with the treads in their second position would form a slide providing an emergency escape from the upper to the lower deck. However, contrary to the assertions of the appellant M4 does not clearly and unambiguously disclose the possibility of the treads being in their second position when the stairs are in their lowered position. The actual disclosure is that when the stairs have been raised the treads may be pivoted into their second position (column 3, lines 47 to 51). As to whether the treads may remain or be placed in their second position when the stairs are in their lowered position M4 is silent. The appellant argues that since figure 7 illustrates the stairs in their lowered position and shows arrows which signify the pivoting of the treads into their second position, there is a disclosure of the combination of those two positions. Such an interpretation goes beyond the actual disclosure, however, because there is nothing which explicitly teaches that possibility.

4.2 The appellant also argues that the treads when in their second position with the stairs raised would form a continuation of the ceiling. However, it is clearly visible in figure 7 that the underside of the treads would be placed higher than the ceiling to an extent which cannot be considered as satisfying the claimed requirement of "forming a continuation of the ceiling".

4.3 A further difference between the subject-matter of present claim 1 and the embodiment of M4 figure 7 resides in the implications of the designation 'emergency escape system'. Clearly, for any previously known system to anticipate the subject-matter of claim 1 it must be either explicitly or implicitly suited to be used for escaping in an emergency. The explicit disclosure of M4 in this respect is the opposite, however, namely that in an emergency the stairs would be moved into their upper position to ensure that the lower deck is free of encumbrance detrimental to an emergency evacuation and to permit closure of the access opening by additionally pivoting the treads to prevent the passage of smoke. Although the appellant reasons that the system of M4 figure 7 nevertheless could be used for an emergency escape, the perceived relevance of that reasoning relies on the appellant's own interpretation of claim 1 which, as set out under point 3 above, the board does not accept. Moreover, the upper and lower decks are not disclosed as a rest area and a main cabin respectively.

4.4 On the basis of the foregoing the board concludes that the subject-matter of claim 1 is new with respect to M4.

Inventive step

5. The appellant's first attack on inventive step is based on the knowledge and ability of the skilled person when presented with the disclosure of M4 as closest state of the art. It reasons that the skilled person faced with the problem of providing emergency evacuation measures to satisfy regulations would realise that the stairs of M4 could be used as an emergency exit slide. However, the teaching of M4 is that the stairs would be moved into their upward position in the event of an emergency evacuation, thereby implying that evacuation from the upper deck would be by other, presumably conventional means. Under these circumstances it seems that the problem as defined by the appellant would not arise and the skilled person would not be looking to provide an emergency escape route from the upper deck to the lower. Furthermore, the problem addressed by M4, to avoid obstruction in the region of emergency exits on the lower deck, implicitly requires that the stairs cannot be used as an emergency escape means and the appellant's reasoning runs contrary to the teaching of M4. Moreover, if the skilled person were nevertheless to attempt to use the stairs as an emergency escape means he would receive no motivation from M4 to provide a slide, particularly as the pivoting stairs having treads numbered 2 to 7 are only one part of a flight of steps including further ones numbered 8 to 11 which are not illustrated as being pivotable. Furthermore, even if the skilled person were to create a slide from the treads the undersurface still would not form a continuation of the cabin ceiling. The board therefore finds that the subject-matter of claim 1 is not rendered obvious by a combination of M4 and the knowledge and ability of the skilled person.

6. A second approach by the appellant is a combination of closest state of the art according to M4 with the teaching of M3 which relates to emergency escape systems for the outside of a building, whereby the appellant argues with reference to decision T 176/84 (OJ EPO 1986, 50) that the skilled person would combine documents in neighbouring technical fields. In a modification of this approach the appellant considers the closest state of the art to be that acknowledged in the patent specification (paragraph [0004]), namely bunks in non-seating areas over cabin monuments such as galley areas.

6.1 M3 addresses the problem that previously known emergency escape systems for buildings required balconies or similar onto which the escape elements could be mounted. The solution was to provide a slide arrangement which mounts on a door which in the closed position is parallel to the wall and which pivots into a horizontal position from which the slide is deployed. In the board's judgement the skilled person faced with the problem of improving emergency escape arrangements in M4 would not consider M3 because it is prima facie not relevant. Firstly it relates to external emergency escape systems for buildings, not such a system in the interior of an aircraft where space and weight play a much greater role than on the exterior of a building. Secondly, the problem addressed by M3 does not exist in the teaching of M4. In this respect the board notes that according to the headnote of T 176/84 (supra): "The state of the art to be considered when examining for inventive step includes … the state of any relevant art in neighbouring fields and/or a broader general field of which the specific field is part, that is to say any field in which the same problem or one similar to it arises and of which the person skilled in the art of the specific field must be expected to be aware." T 176/84 (supra) therefore does not support the notion that M3 would be in a neighbouring technical field and the skilled person beginning with state of the art according to M4 would not consider it. Even if he were to do so it would not lead him to the subject-matter of present claim 1 because in each embodiment according to M3 a flap 14 is provided in addition to the slide. Application of that teaching to M4 would fail to provide the feature that the slide comprises an undersurface forming a portion of the ceiling of the cabin. The same conclusions are reached when considering the alternative state of the art acknowledged in the patent specification.

6.2 The board concludes from the foregoing that the subject-matter of claim 1 is not rendered obvious by the teaching of M3 in combination with either of the alternative closest states of the art chosen by the appellant.

7. In a further approach the appellant considers the subject-matter of claim 1 to be rendered obvious by a combination of the teaching of M7 with the closest state of the art according to M4. M7 relates to stairs having treads which are pivotable by a hand-operated linkage between the conventional horizontal position and a lowered position in which the treads form a continuous surface in order to ease the movement of heavy objects between the floors connected by the stairs. As already set out under point 5 above, the skilled person beginning with M4 has no cause to provide an emergency escape system between the two levels and particularly not by modifying the stairs which according to M4 are moved into a non-operative position in the case of an emergency. For that reason he would not go in search of an arrangement permitting the stairs to be converted into a slide. Even if he were to combine the teachings of M4 and M7 he still would not arrive at the feature that the slide comprises an undersurface which in the upper position forms a continuation of the cabin ceiling. This feature is not present in M4 and does not result from M7 in which the stairs themselves are not movable. Indeed, the teaching of M7 extends no further than the provision of a mechanism for operating pivoting treads already present in the stairs of M4. Also the combination of M4 and M7 therefore fails to render the subject-matter of claim 1 obvious.

8. Since claims 2 to 11 contain all features of claim 1 the above conclusions regarding novelty and inventive step are equally applicable to those claims. Consideration of the auxiliary requests therefore is unnecessary.