Wednesday 23 October 2013

T 500/11 – You May Pick It


Claim 1 of the auxiliary request before the Board read:
1. Method for the production of trichlorosiliane by reaction of silicon with HCl gas at a temperature between 250° and 1100°C, and an absolute pressure of 0.5 30 atm in a fluidized bed reactor, in a stirred bed reactor or in a solid bed reactor, characterised in that the silicon supplied to the reactor contains between 550 and 10 000 ppm chromium. (my emphasis)
Claim 1 as granted (and of the main request) was identical, only the lower limit of the chromium content was different (50 ppm). However, the Board had found this claim to lack novelty over document D1, which disclosed a range of 5 to 200 ppm.

In what follows, the Board examines compliance of the auxiliary request with A 123(2):

[3.1] The amendment in claim 1 at issue corresponds to the restriction of the range “between 50 to 10000 ppm of chromium” by the lower end value of 550 ppm. It is uncontested that there is a literal basis for this specific value in example 3 of the patent in suit, however not in combination with the other features of amended claim 1 under dispute.

[3.2] [The opponent] argued that the amendment consisted of an inadmissible intermediate generalisation in the sense of T 962/98, because the feature 550 ppm Cr was inextricably linked to the other features of the process according to example 3 – namely the type of reactor, the pressure and temperature, the particle size and the contact time – and thus this specific value could not be arbitrarily extracted from its context. [The opponent] referred also in this respect to paragraph [0003] of the patent which disclosed that the “selectivity and reactivity will depend strongly on the process temperature when silicon and HCl is reacted”. This would make clear that the temperature was a feature which was inextricably linked to the selectivity to TCS.

[3.3] The question to be answered now is whether the feature “550 ppm Cr” is inextricably linked to the other features defined in Example 3 of the patent in suit.

The board observes in this respect that there is no doubt that not only the concentration of chromium has an influence on the selectivity of TCS but also other parameters too, such as e.g. the particle size, the pressure, the temperature, and the contact time in the reactor. All these features however are parameters which may be varied individually and each of these variations would necessarily lead to a different result on the selectivity to TCS.

If the feature “550 ppm chromium” was inextricably linked to specific other parameters of Example 3, this would mean that the selectivity to TCS would only be achieved in the definite combination of “550 ppm chromium” with the specific other parameters of example 3. This however is manifestly not the case here.

Moreover, according to paragraph [0020] of the patent in suit, the addition of chromium to silicon is described very generally as improving the selectivity to TCS in the reaction of silicon with gaseous HCl.

It follows from the above considerations that the different parameters, and in particular those in Example 4, can be varied independently one from another and that there is no reciprocal relationship, which would imply that the concentration of chromium is part of an entanglement in which a variation of the other parameters is not allowed.

[3.4] The question at issue was already addressed in several decisions, in particular in T 273/10 or T 962/98, to which the board refers in the following paragraphs.

[3.4.1] According to T 962/98 [2.5], an intermediate generalisation would be admissible if the skilled person could recognise without any doubt from the application as filed that the characteristics taken from a working example were not closely related to the other characteristics of the working example and applied directly and unambiguously to the more general context.

[3.4.2] In decision T 273/10 [14.2-3], a claim amended by inclusion of a bundle of features extracted from a specific embodiment had been found allowable because the bundle of features proposed as an amendment comprised all the features essential for the performance of the invention. Further, according to T 273/10, those features of the embodiment which did not contribute to solving the problem underlying the invention did not have to be part of the claimed subject-matter resulting from the amendment.

[3.4.3] In the case at issue, as explained in point [3.3] above the aim of the invention – namely increasing the selectivity to TCS – is merely achieved by addition of selected amounts of chromium to silicon and thus this feature is not “closely related to the other characteristics of the working example and applies directly and unambiguously to the more general context” as required in T 962/98.

[3.4.4] The present decision is also in line with decision T 273/10 since the proposed amendment comprises the feature essential for the performance of the invention, namely a certain amount of chromium, and moreover those features of the embodiment which do not contribute to solve the problem underlying the invention are not part of the claimed subject-matter resulting from the amendment.

[3.5] It follows from the above considerations that the gain of selectivity is solely due to the presence of chromium in the silicon feedstock, and that the picking out of the value 550 ppm from the working example 3 is therefore plainly acceptable in the case at issue, with the consequence that claim 1 of this request meets the requirements of A 123(2).

Dependent claims 2 to 6, which have a basis in the corresponding dependent claims 2 to 6 of the application as filed, also meet the requirements of A 123(2).

I for one am not very comfortable with the fact that isolated values taken from examples may become boundaries of claimed ranges, which I consider to be a completely new teaching, but there seems to be some consensus that this is alright.

Should you wish to download the whole decision, just click here.

The file wrapper can be found here.

10 comments:

Suleman Ali said...

The EPO is way-too strict on added matter, and so any decision which gives a little more leniency is to be welcomed. I've not seen any other Patent Office agonise so much over concepts like 'inextricably linked'.

Anonymous said...

They indeed add a lot of matter to the content of Art 123(2) as originally signed.

Raoul said...

The decision might seem a bit unsettling, but in view of the case it appears fully justified. The fact that there are ranges does not change the situation.

This is one of the very few examples where an intermediate generalisation is justified.

The contrary happens much more often ...

For once that a Board decides that there is no intermediate generalisation, it should be greeted with good feelings.

Karl said...

I think the EPO needs to use a foreseeability test like they use in the US for doctrine of equivalents. If the applicant could not foresee a particular amendment might be needed there should be a more lenient burden to show basis in the application. No matter how well a specification is written a previously unknown document can be found in the search which needs an amendment one could not have predicted, and if that happens I think the unfairness of the situation needs to be appreciated. The patent system is about rewarding good inventions, not being able to predict the future.

Tom said...

@ Karl: have a look at claim 1 and 2 as filed. They specified extremely broad ranges as characterizing feature. I would say it is not really surprising if something is found within your two orders of magnitude. I don't understand why they did not mention any narrower range in the description (rather, less broad range).

Anonymous said...

Karl, are you saying that when an application is drafted and later a damaging document turns up, that should be disregarded because the applicant did not know it at the time of drafting? Then what do you mean by "good invention"? Surely not one that is not novel? Sorry, I fail to see the logic of what you say. The absolute requirement of novelty means that even if you did not know about a document, nevertheless it may be used against you. Which is also true for documents used against inventive step. One cannot get a patent for a "good invention" (whatever that nay mean) when it is not novel and inventive. Then it simply is not an invention, good or not.

Anonymous said...

Tom , indeed, why were no smaller ranges indicated? That is elementary drafting which I see neglected more and more often. Are the good patent agents disappearing, or aren't they employed anymore or until after the harm has been done?

Anonymous said...

If the original specification discloses a range and gives examples at particular points within thís range, what subject matter is added by selecting one of the particular examples as a boundary point? The disclosure of the original range teaches that the invention may be implemented at all values within this range and the specific example teaches that this particular value is also enabled. Restricting the claimed range would in my view generally not add subject matter unless there are a number of variables present and this combination is not disclosed in connection with the claimed new range.

Anonymous said...

Exactly the last sentence of anonymous 10.42 is the case with examples. Many variables have fixed values in an example and it is not allowed to pick one value and restrict it without having a look at the other values. Another point is that it is possible to get a patent for "selection inventions" are allowed and great care has to be taken that an application is not changed in a way as to result in such a selection invention, when it has not been disclosed to begin with.

Anonymous said...

Exactly the last sentence of anonymous 10.42 is the case with examples. Many variables have fixed values in an example and it is not allowed to pick one value and restrict it without having a look at the other values. Another point is that it is possible to get a patent for "selection inventions" are allowed and great care has to be taken that an application is not changed in a way as to result in such a selection invention, when it has not been disclosed to begin with.