T 0255/03 31-08-2004

Reasons for the Decision

1. The appeal is admissible.

2. Interpretation of claim 1

2.1. Claim 1 comprises the following feature: "the wash tank (1, 4) is provided with water filtering means (5), the wash tank being connected with drain means (6) upstream of the filtering means (5)."

Thus, it is clear for a person skilled in the art, that the drain means are directly connected to the wash tank, and that therefore, in the meaning of the patent in suit, the term "drain means" designates the whole of the piping which leads from the tank to the drain and not only the drain pump and the pipe downstream thereof.

Furthermore, the term "upstream" in connection with the filtering means and the drain means indicates that the water flows from the wash tank into the drain means without passing through the filtering means (i.e. by- passing the filtering means) and this irrespectively of the water flow direction. Moreover, in the present case, since the aim of the drain means is to convey the water from the wash tank to waste, and not in the reverse direction, the water flow direction is clearly defined.

2.2. Furthermore, claim 1 comprises the following feature: "said reservoir (11) forms a part only of said water supply circuit (8-14)."

The appellant argued that it was unclear whether this means that the reservoir is only one part of the water supply circuit (i.e. does not form the whole water supply circuit) or that the reservoir forms part only of the water supply circuit (i.e. is not part of the water drain circuit).

However, when interpreting the claims of a patent a skilled person should rule out interpretations which are illogical or which do not make technical sense. He should try to arrive at an interpretation which is technically sensible and takes into account the whole of the disclosure of the patent.

In the present case, the interpretation according to which the reservoir does not form the whole water supply circuit would not make any sense from a technical point of view and thus, has to be rejected.

Furthermore, claim 1 also comprises the following feature "the wash tank being connected with drain means (6) upstream of the filtering means (5), the drain means being separate from said water supply circuit (8- 14)" which implies that the reservoir, which according to any possible interpretation, is part of the water supply circuit cannot also be part of the drain means, since the drain means are said to be separate from the water supply circuit.

This is confirmed by figure 1 and the description of the patent where it is indicated:

- column 2, lines 30 to 32 that "the portion of the sump 4 situated upstream of the filter 5 is connected with a pipe 6 associated to a drain pump 7",

- column 3, lines 31 to 33 that "pump 7 is operated in view of delivering to the drain, through pipe 6, the water collected in the sump 4",

- column 4, lines 6 to 11 that "conduit 14 connects with the sump 4 downstream of filter 5 ... this enables only filtered water ... to be recovered and temporarily stored in the reservoir 11."

Therefore, in the meaning of the patent in suit, the feature in question has to be interpreted as meaning that the reservoir forms part only of the water supply circuit and not part of the water drain circuit.

2.3. In the expressions "said pipe (14) branching off the wash tank in correspondence of a portion thereof located downstream of said filtering means (5)", "downstream" indicates that the pipe is connected to the tank via the filtering means, i.e. that water which flows from the one to the other always passes through the filtering means.

3. Novelty

3.1. The Board is satisfied that none of the cited prior art documents discloses all the features of claim 1 of the patent in suit. Indeed, during the oral proceedings the Appellant withdrew his objection of lack of novelty.

4. Inventive step

4.1. E1 is considered to be the closest prior art document.

In the washing machine disclosed therein, the water from an operating phase can be stored in a volumetric metering reservoir for re-use during a subsequent cycle. The reservoir, however, forms part not only of a water supply circuit of the machine but also of a water drain circuit of the machine itself, so that the reservoir is contaminated by dirty water at the end of each operating cycle.

4.2. Therefore, the technical problem to be solved by the present invention is to propose a washing machine with a water recovery arrangement which improves hygienic and scale- formation problems (see patent in suit, column 1, lines 53 to 57). This problem is in essence solved by the following features stated in the characterising part of claim 1:

- the wash tank is provided with water filtering means,

- the wash tank is connected with drain means upstream of the filtering means,

- the drain means are separate from said water supply circuit,

- said pipe branches off the wash tank in correspondence of a portion thereof located downstream of said filtering means,

- said reservoir forms a part only of said water supply circuit.

4.3. This problem is neither identified nor addressed by the cited documents (E1 and E2) and therefore there is no incentive for a skilled person to combine the teaching of said documents in order to solve the posed problem.

4.4. The Appellant argued that a person skilled in the art would solve this problem by providing filtering means as disclosed in E2 and thus would arrive at the subject-matter of claim 1 of the patent in suit.

The Board cannot agree to this reasoning.

Indeed, E2 discloses a filtering system to be installed in the sump of a washing tank. However, E2 does not disclose a volumetric metering reservoir, in which water from an operating cycle can be stored for re-use during a subsequent cycle. Thus, no teaching is provided by E2 as to how contamination and scale formation could be reduced in such reservoir. There is also no disclosure or suggestion of a volumetric metering reservoir which is exclusively part of the water supply circuit, as stated in the characterising part of claim 1.

More precisely, the Appellant argued that a skilled person would provide the machine according to E1 with a perforated wash drum and a surrounding wash tank so that a sump could be provided in the wash tank (as disclosed in E2) in order to install the filtering means therein.

The Board cannot agree to this reasoning either. Once a person skilled in the art has chosen a starting point (in the present case E1), he is bound afterwards by that choice (T 570/91, section 4.4). The choice of the starting point (in the present case a washing machine provided with a watertight drum), made in the knowledge of the respective benefits and drawbacks of the type of machine concerned, defines the framework of further development (within this particular type of machine). A change of type of machine during the further development of the consciously chosen type, to another type, which was previously known but had not been chosen (a machine with a perforated drum surrounded by a wash tank), can only be seen as the result of an ex- post-facto analysis (T 1040/93, sections 5.1 and 5.2).

Furthermore, in the present case it would not be sufficient for a skilled person to change the type of drum system of the washing machine according to E1 and to provide it with filtering means to arrive at a machine as claimed in claim 1 of the patent in suit. He would also be obliged to completely modify the hydraulic circuit, to such an extend, that except the pumps and the reservoir no other part of the core of the machine originally disclosed in E1 would remain unchanged.

However, such modifications cannot be obvious for a person skilled in the art, because said modifications would be so extensive that it would be uncertain whether or not the resulting machine would still be able to carry out the washing process taught by E1.

Finally, the washing method disclosed in E1, foresees that the used water is always pumped back into the said reservoir (to measure the recovered quantity of water in order to optimise the subsequent washing sequences) before being pumped to waste. Consequently, the reservoir would still be part of the drain means (this however would be contrary to the provisions of claim 1 of the patent in suit) and thus, the thereby resulting machine would not disclose all the features of the subject-matter of claim 1 of the patent in suit.

Consequently, the subject-matter of claim 1 of the patent in suit involves an inventive step.