T 2296/09 31-01-2012

Reasons for the decision

1. Procedural issue

According to the appellant the minutes of the oral proceedings before the opposition division are inconsistent with regard to point 10 according to which "... the chairman notified that the subject-matter of claim 1 does not meet the requirements of inventive step in the sense of Article 56 EPC. It was decided to revoke the opposition." and the final order referred to therein, that "The opposition is rejected".

Considering that the final order as stated in the minutes corresponds to the order of the decision under appeal and that, undisputedly, the decision as such is clear and consistent with the order given therein the Board concludes there is only an inconsistency in the minutes combined with a rather strange conclusion. As the appellant declared that it did not wish to submit a request concerning this issue, this decision does not have to deal with it any further. For completeness sake the Board notes that the appellant has not requested correction of the minutes and that the Board would in any case not have been the right addressee for such a request.

2. Disclosure of document E1

2.1 It is common ground that the relevant disclosure of E1 to be considered resides solely in its drawings and that these drawings, as can be derived from figure 2, disclose a spray gun of the kind defined by the preamble of claim 1.

Beyond that the parties are divided as to the extent of the disclosure derivable from these drawings.

2.2 According to the impugned decision (reasons, no. 4.2) and the respondent (cf. section VI. (a)) these drawings can only be regarded as conventional sketches. While the decision under appeal remains silent concerning the reasoning underlying this assumption the respondent referred to the intended use of these drawings. In its view these drawings are patent drawings which normally, and the present drawings making no exception, show in a general outline an embodiment according to the respective invention. Thus details not addressed as part of the invention in the description of E1 but only shown in the drawings, like it is the case for the projection of the front end of the paint nozzle tip as shown in figure 2, cannot be considered as being part of the disclosure.

Consequently this projection cannot be considered as corresponding to the one defined by feature (i) of claim 1 of the patent in suit but merely as a negligible pictorial detail for which no reason is given in E1, or even as a drawing inaccuracy or an unforeseen deviation in the pictorial presentation of the spray gun concerned. This aspect becomes even more evident considering the large number of prior art documents which disclose spray guns of the kind concerned for which the front end of the paint nozzle tip does not project.

2.3 The Board in this respect finds, however, the arguments of the appellant (cf. section V. (b)) more convincing. Due to the accuracy and completeness of these drawings and due to the fact that apparently all elements constituting the spray gun as well as their relationships are shown in great detail, also the one clearly shown in figure 2, namely that, as defined by feature (h), the front end of the paint nozzle tip projects from the front end of the central opening of the air cap, is disclosed by E1.

From the drawings of E1 it cannot be concluded that only essential details relating to the invention referred to in the description are shown as asserted by the respondent. Furthermore it needs to be taken into consideration that the projection concerned is shown in the same order of magnitude as other elements (in particular ones with associated reference numerals) like the air grooves 1a and the annular slit 4 formed, corresponding to feature (d), between an end portion of the nozzle and the central opening formed in the air cap.

Further, although it has been asserted that a large number of documents exists showing spray guns of the kind concerned without the front end of the paint nozzle projecting, with the result that the projection shown in figure 2 of E1 should be disregarded, no such documents have actually been cited or submitted and no convincing reason has been given as to why - and which - disclosure(s) of other documents not referred to in E1 should be taken into account in the assessment of the disclosure of this document.

At present it can be left open to what extent the above reasoning applies likewise to the argument of the appellant that in determining the disclosure of the drawings of E1 the rather similar drawings of the patent in suit and the corresponding description should be taken into account.

2.4 As can be derived from the above considerations the disclosure of E1 involves a spray gun according to the preamble of claim 1 in which, corresponding to feature (h), the front end of the paint nozzle projects from the front end of the central opening of the air cap.

2.5 Concerning the question of whether or not with the projection of the front end of the paint spray gun also a value for the length is disclosed which, as argued by the appellant (cf. section V. (c)), corresponds to a value of the value range defined by feature (i) the Board finds the arguments of the respondent (cf. section VI. (b)) more convincing, according to which the impugned decision is correct in not considering measurements taken from the drawings of E1 as a disclosure by these drawings.

The reason given in the impugned decision is that the drawings can only be regarded as a conventional sketch which is not necessarily true to scale (reasons, no. 4.2).

2.6 According to the appellant it is evident in view of the impression given by these drawings, in particular their accuracy and completeness, that these drawings show the spray gun in reduced but true scale. Since the scale of the drawings and thus measurements taken therefrom can easily be transformed into values present in the actual size spray gun, like all dimensions shown in the drawings, the value for the length of the projection of the front end of the paint nozzle tip measured in figure 2 and transformed to its actual size needs to be considered as disclosed by E1. In this respect it should be taken into account that the transformation factor from the reduced scale of the drawings in E1 to the actual size of the spray gun can easily be determined taking the actual size of the spray gun into account, which can easily be determined considering its nature as a hand held tool.

Although at present it appears that by themselves the drawings of E1 can be considered as being true to scale the determination of the transformation factor referred to is subject to uncertainty, as the fact that the spray gun is a handheld tool does not lead to only one precisely determinable actual size. As a result, only a range of sizes for spray guns satisfying the constraints imposed on their size due to their nature as hand held tool is possibly derivable from the drawings.

2.7 Since this leads to different values for the projection of the front end of the paint nozzle tip of figure 2, no specific value for the length of the projection (nor one specific range of values) can be considered directly and unambiguously derivable from E1.

3. Novelty

From the above assessment of the disclosure of document E1 it is immediately apparent that the spray gun according to claim 1 differs from the one disclosed by E1 by the value range defined by feature (i) for the length of the projection of the front end of the paint nozzle tip.

The subject-matter of claim 1 is thus novel over the spray gun disclosed by E1 (Article 54 EPC).

Concerning the further documents E2 and E3 it is apparent that they likewise do not disclose a value range for the projection of the nozzle tip corresponding to feature (i). Furthermore it has not been disputed that with respect to the spray guns of E2 and E3 additional distinguishing features result e.g. from different structures and arrangements of the air grooves.

Since, as can be derived from the following, the subject-matter of claim 1 cannot be considered as involving an inventive step with respect to the spray gun according to E1 the examination of novelty and the disclosures of documents E2 and E3 needs no further pursuing.

4. Inventive step

4.1 Impugned decision

4.1.1 From the impugned decision it cannot be derived which one of cited documents E1, E2 and E3 has been considered as constituting the closest prior art in the examination of inventive step as required when the problem solution approach is followed.

Concerning the examination of inventive step E1, E2 and E3 have been considered as being completely silent about the range of values with which the front end of the paint nozzle tip projects (reasons, no. 4.2).

Based on this assessment of the disclosures of these prior art documents it has been concluded, unfortunately without reference to any effect associated with the assumed distinguishing features and any problem solved thereby over the prior art, that since the characterising part of claim 1 is not known from any of the citations, this aspect is also not suggested by the prior art and that therefore this claim's subject-matter is not obvious.

4.1.2 The decision under appeal, as far as it can be understood that it considers feature (i) as not being disclosed by E1, E2 or E3, corresponds to the result of the examination with respect to novelty indicated above (cf. point 3).

4.1.3 According to the appellant the reasoning of the impugned decision that E1, E2 and E3 are completely silent about the range of values with which the front end of the paint nozzle tip projects is not correct. According to the respondent the assessment of inventive step according to the impugned decision is correct.

4.2 Closest prior art

The appellant argues that the spray gun of E1 can be considered as closest prior art for inventive step since, as can be concluded from the examination of novelty (cf. point 3 above) this document discloses a spray gun having all features in common with the spray gun according to claim 1 with the exception of feature (i).

According to the respondent already the selection of E1 as closest prior art out of the large number of available documents relating to spray guns, among which there are more with the paint nozzle tip not projecting as defined by feature (h) is based on the knowledge of the spray gun as defined by claim 1 and thus, inadmissibly, on hindsight.

The Board does not find this argument convincing. It is true that knowledge of the patent in suit is to be taken into consideration when it has to be decided which prior art document is to be considered as the starting point (and thus as closest prior art) for the examination of inventive step based on the generally applied and accepted problem solution approach. If various documents are available the one is usually chosen as closest prior art which is closest to the claimed subject-matter in terms of features and purpose. The documents available for such a choice are at present E1, E2 and E3. Although the respondent has alleged this to be a large number of other prior art documents showing spray guns without a projecting paint nozzle tip it could not, upon request by the Board, cite any document other than the documents already considered in the impugned decision (E1, E2 and E3) and referred to in the grounds of appeal which had, in addition, to be considered in the selection of the closest prior art.

Moreover it is generally accepted that in order to satisfy the requirement of Article 56 EPC inventive step has to be acknowledged over any feasible prior art document relating to the technical field of the invention. It is evident from the above considerations for novelty that E1 relates to the technical field of the invention and to its purpose, having a projecting paint nozzle tip.

The spray gun disclosed by the drawings of E1 is thus considered as representing the closest prior art.

4.3 Distinguishing feature, effect and problem to be considered with respect to E1

4.3.1 As can be derived from the result of the examination with respect to novelty (cf. point 3 above) the subject-matter of claim 1 is distinguished from the spray gun of E1 by feature (i) defining a value range of 0.3 to 0.8 mm for the projection of the front end of the paint nozzle tip.

4.3.2 It is undisputed that the projection of the paint nozzle tip as such, as defined by feature (h), has the advantageous effect stated in the patent in suit (cf. section [0036]) in that it contributes "to prevent the paint from adhering to the air cap 2 and thus assure a stable spraying of the paint".

This effect is, however, already present in the spray gun of E1 since as indicated above (cf. points 2.3 and 2.4 above) this spray gun is of the kind having a projecting paint nozzle tip as defined by feature (h). This effect is furthermore evident since the projection leads to a distance between the front end of the nozzle tip and the area of the air cap adjacent to it. It is thus unlikely that paint leaving the paint nozzle is directed to the portion of the air cap immediately surrounding the paint nozzle.

4.3.3 According to the appellant the value range defined by feature (i) encompasses values for the projection of the paint nozzle tip for which only the effect attributed to feature (h) can be obtained but no further effect, which moreover is neither proven nor evident. The value range of feature (i) is thus the result of an arbitrary proposition of values for the projection according to feature (h) already known from E1.

According to the respondent it is evident that the value range according to feature (i) is the result of an inventive proposition since a projection of the paint nozzle tip in the defined value range not only leads to an enhancement of the effect attributed to feature (h) but moreover to an improvement of the flow of the paint particles in that atomization of the paint will be improved so that this paint flow is more uniform while the negative impact of shear forces on the flow will be minimised.

4.3.4 For the Board, the effects attributed to feature (i) are not referred to in the patent in suit and no evidence concerning their occurrence has been provided. The respondent referred to favourable test results having been obtained but failed to submit them for consideration.

Moreover upon request by the Board the respondent could not rule out that, even if such further effects would be considered, they solely could be considered as being caused by feature (h).

Consequently no effect can be considered as being caused by feature (i).

4.3.5 The problem to be considered starting from the spray gun according to E1 thus does not go beyond the necessity to fill the gap in the disclosure of this document with respect to the value for the projection of the paint nozzle tip or, in other words, to give a value for the projection of the paint nozzle tip which is shown in figure 2 but for which no dimension is given.

4.4 Obviousness

4.4.1 The Board considers the argument of the appellant as convincing that, even if it is considered that E1 does not directly disclose a value within the range defined by feature (i) for its spray gun with the projecting front end of the paint nozzle, starting from E1 in an attempt to reduce the spray gun according to this document to practice, information concerning the length of this projection can be arrived at from this document taking the approach based on a measurement taken from figure 2 of E1 as outlined in connection with the disclosure of E1 (cf. point 2.6 above). The Board furthermore concurs with the view expressed by the appellant that such an approach is obvious since it comes within customary design practice.

Thus in order to actually build a spray gun as disclosed by E1 measurements of the dimensions of the various elements of the spray gun and their respective relationships have to be taken from the drawings. These measurements can then be transformed, from the reduced scale of the drawings, into a scale representative for the actual size of such a spray gun, this approach being justified since the drawings are considered true to scale, accurate and complete.

Since in this case the information derived via measurements from these drawings is not limited by the condition that it should be directly and unambiguously disclosed, but serves to determine dimensions which are necessary as starting points for the manufacture of the spray gun of E1, it is irrelevant that, as indicated with respect to the disclosure of E1 for the purpose of novelty (cf. point 2.6 above), the determination of the transformation factor, to transform measurements taken from the drawings into equivalent dimensions corresponding to the actual size of the spray gun is subject to uncertainties.

In any event such uncertainties or ambiguities cannot be considered as being such that the values obtained in this manner cannot fulfil their purpose of starting values for the manufacture of the disclosed spray gun. These starting values will be, depending on circumstances, in any case subject to further modification e.g. in order to optimise such a spray gun in view of its intended use (which depends on a variety of parameters neither addressed in E1 nor the patent in suit) like e.g. the cross-section of the annular slit and of the air grooves, material properties of the paint particles to be sprayed and the air pressure provided.

4.4.2 Determining the value for the length of the projection of the paint nozzle tip in the outlined manner the Board finds the argument of the appellant convincing that such a value is of a magnitude that it lies within the value range of feature (i) or is so close to it that the claimed range cannot involve inventive step, by lack of a particular effect only obtained in this range (see point 4.3.4 above).

Concerning the lower limit of 0,2 mm for his length, the Board observes that this appears to be in any case necessary to surpass any tolerances which will have to be allowed for the position of the paint nozzle tip relative to the front end of the central opening in the air cap.

4.4.3 Considering that the spray gun as defined by features (a) to (h) is already known from E1 as outlined above the spray gun according to features (a) to (i) of claim 1 is obvious in view of E1.

It thus can be left open whether consideration of E2 or E3 by itself or in combination with E1 would also have led to the same result.

The spray gun of claim 1 thus cannot be considered as involving inventive step (Article 56 EPC).

4.4.4 The above result holds true considering the following arguments of the respondent:

According to a first argument a technical prejudice exists against a projection of the paint nozzle tip as defined by features (h) and (i), the reason being that the skilled person would rather seek to protect the protruding front end of the paint nozzle tip than to expose it to any possible damage. Concerning this argument it has been indicated by the Board in the annex (point 7.5.1) that it appears to be necessary to determine whether such an alleged prejudice can be considered as proven. The argument concerned has been repeated by the respondent during the oral proceedings, in particular with respect to cleaning or exchanging of a nozzle, however, without any further supporting evidence.

While it can be agreed that the risk of damage due to a projection of the front end of the paint nozzle is to be avoided it is evident that in case the apparent advantage of such a projection is to be obtained (cf. point 4.3.2 above) the associated exposure of the front end of the paint nozzle tip is "part of the bargain".

Thus the advantage and the disadvantage of the projection concerned need merely to be weighed against each other, as has done the inventor of E1, because it is undeniable that the paint nozzle tip does project out of the air cap, as shown in figure 2. This is quite different from the existence of a prejudice.

For completeness sake the Board observes that the alleged prejudice concerned only the projection of the front end of the paint nozzle tip as defined by feature (h) already known from E1 and not the range of values for such a projection according to feature (i) and thus not with respect to the distinguishing feature as determined by the Board.

According to a second argument E1 does not mention in its description any benefit for the projection of the paint nozzle tip, such that the skilled person would have disregarded the disclosure of such a projection given by figure 2. This argument has (indirectly) already been dealt with in connection with the determination of the disclosure of E1 (cf. point 2.3) where it has been concluded that feature (h) is part of the disclosure of E1.

Furthermore in this connection it needs to be considered that the effect attributed to feature (h) arises automatically due to the projection of the front end of the paint nozzle tip without any further measures being necessary (cf. point 4.3.2 above).