Tuesday, 2 February 2010

T 1180/07 – Hasty Generalisation

The opposed patent concerns a venting device for a crank case.

Claim 1 as granted reads:

A venting device for a crankcase of an internal combustion engine with a centrifugal oil separator (1) comprising a mixture inlet (13) for an air-oil mixture and an air outlet (12) for clean air as well as an oil outlet (14) for oil, and said centrifugal oil separator being designed as a plate separator (1) having a stator (2) in the form of a housing (7) into which a rotor (3) comprising several plates (9) is placed which are located along the rotor axis (19) parallel to each other and coaxial to the rotor axis (19) whereby a gap (10) is formed between each two neighbouring plates (9), said gap joining an annular space (11) formed inside the rotor (3) with a space (8) which surrounds the rotor (3) inside the housing (7), whereby the annular space (11) of rotor (3) is joined to a first connection (12), and the space (8) of housing (7) to a second connection (13) as well as a third connection (14) which serves as the oil outlet, characterised in that the first connection (12) serves as the air outlet and the second connection (13) serves as the air inlet.

Claim 1 of the main request differs from Claim 1 as granted by the addition : “wherein each plate (9) essentially has the form of a truncated cone shell that narrows with increasing axial distance with respect to one of the front sides of the centrifugal oil separator (1) which is parallel to the rotor axis (19) or inclined with respect to this axis and which comprises a mixture inlet.” [1.1]

This amendment is partially based on claim 6 of the application as filed. According to this claim, “each plate essentially has the form of a truncated cone shell.” However, the arrangement of the plates is not defined in claim 6. [1.2]

The orientation (Ausrichtung) of the plates as defined in claim 1 is disclosed only in the venting device according to figure 1 of the application. This is not disputed by any of the parties. [1.3]

Figure 1 is the only figure of the application and corresponds to “preferred embodiments” of the invention which “are discussed in more detail in the following description.”

The description also mentions other embodiments but there is no disclosure whatsoever of the arrangement (Anordnung) of Figure 1 with a different orientation of the plates. Rather the skilled person sees from Figure 1 that the orientation of the plates is functionally linked to other parts of the venting device shown in the figure. Among other things, the orientation of the plates is adapted to the location of the oil outlet 14, which is situated in a lower part of the front plate opposite to the shaft sealing and the mixture inlet. The orientation and arrangement results in separation of oil from an oil/air-mixture by means of a centrifugal force radially towards the outside. Thanks to the arrangement of the oil outlet and the arrangement of the plates the separated oil does not flow into the mixture inlet nor into shaft sealing because the oil outlet is provided in a lower part of the front plate. Thus a functional link between the orientation and shape of the plates and the location and arrangement of the oil outlet is unambiguously discernable for the skilled person. [1.4]

Therefore, there is no direct disclosure of the combination of features defined very generally in claim 1. The definition in Claim 1 of the orientation of the plates without the location and arrangement of the oil outlet shown in Figure 1, therefore constitutes a so-called inadmissible intermediate generalisation (see e.g. T 1408/04) with respect to the original disclosure. Therefore, the subject-matter of claim 1 extends beyond the content of the originally filed version and does not satisfy the requirements of A 123(2). [1.5]

The [patent proprietor] argued that only features that are essential over the prior art are to be defined in claim 1 when the claim is amended.

However, the question of whether a feature is essential or not with respect to some prior art is not relevant for the assessment of a amendment with respect to A 123(2) because this provision refers to the disclosure of the application and not to the disclosure of the prior art.

According to the established case law of the Boards of appeal, amendments are allowable under A 123(2) only if they are directly and unambiguously disclosed in the application (see e.g. G 11/91). [1.6]

The [patent proprietor] further argued that the disclosure of Figure 1 is not to be considered as limitative. Therefore, the definition of other features from Figure 1 is not necessary.

It is indeed correct that Figure 1 only shows one embodiment and that the description of the application discloses several possibilities for alternative embodiments. However, the application does not contain any disclosure of an alternative location or arrangement of say the oil outlet with respect to other components of Figure 1 to which the oil outlet is functionally linked (see e.g. T 129/08 [4.2]). [1.7]

The [patent proprietor] further cited T 583/93 in support of its arguments.

It follows from this decision (point 4.5 of the reasons) that for an amendment to be allowable under A 123(2) it is required that there be an “adequate basis” in the application as originally filed. This is precisely not the case for claim 1 because there is no direct and unambiguous disclosure of the combination that is defined in claim 1 (only). [1.8]

The allegation of the [patent proprietor] that the plates are defined in claim 5 as granted (claim 6 of the application) is correct, but the orientation of the plates as claimed in claim 1 is not defined in claim 5 as granted. This feature is only found in Figure 1, where it is, as mentioned above, only disclosed in combination with other features. [1.9]

Decisions like this one show that in mechanical applications, it is wise to have more than one embodiment depicted. It may make it easier to distinguish between structural/functional links and accidental combinations of features.

To read the whole decision (in German), click here.