T 0204/83 (Venturi) 24-06-1985

1. The appeal complies with Articles 106, 107 and 108 EPC, as also with Rule 64(b) which requires that the statement of grounds indicate the extent to which amendment or cancellation of the decision is requested. The expression "to lodge an appeal" against a decision of the Examining Division should be understood as meaning that the appellant is asking that the decision be set aside in its entirety (See Decision T 07/81, "Dyeing of linear polyamides/CIBA-GEIGY, OJ (EPO) 3/83, p. 98).

2. The claim gives no cause for objection on formal grounds. Moreover, the objections raised by the Examining Division were based entirely on Article 54 EPC.

3. The Board concurs with the Examining Division in recording US-A-3 110 626 as constituting the closest prior art. This patent relates to an apparatus for uniformly and accurately coating discrete solids by ensuring that a maximum amount of such solids is brought into contact with a minimum amount of coating material for a given period of time (see column 1, lines 38 to 54). The apparatus is composed of four elements, namely: (a) a coating chamber having a tubular or conical control element axially positioned within a funnel-shaped base region, (b) a Venturi tube connected to the base of the coating chamber and having an atomiser assembly axially positioned and vertically translatable within it for injecting the liquified coating material, (c) a means for supplying a gas stream to pass first through the coating chamber, (d) a means for separating discrete solids taken off with the gas stream at the top of the chamber and feeding them back to the chamber (see Claim 1). Moreover, it is expressly stated that the term "Venturi" used in this context does not necessarily mean that the design dimensions are those generally associated with a true Venturi by a person skilled in the art (see column 3, lines 23 to 27). The coating apparatus is designed for batch operation and the mass of solid particles circulate within the coating chamber. As they move downwards along the chamber walls they become mixed in the lower part of the chamber with particles that have left the gas stream as described in (d) and collected by the Venturi. There they are again entrained in the gas stream and move upwards within the control portion of the coating chamber (see column 5, line 55 to column 6, line 11). It is clear from the foregoing that the conventional apparatus displays the features mentioned in the prior art part of the claim and some of those included in the characterising clause, namely the fact that the cylindrical portion is inserted between the narrow ends of the frustoconical granulating chamber and gas inlet duct which are arranged to taper in opposite directions. At first glance the only difference between the application and the US patent lies in the height of the cylindrical portion which is greater than 0.5 d and less than 0.66 d, d being the smallest diameter of the frustoconical portions.

4. The question that arises is whether this feature is novel or whether, as the disputed decision maintains, it may be derived directly and unmistakably from the US patent by a person skilled in the art. Article 54(2) EPC lays down that the state of the art comprises everything made available to the public by means of a written or oral description, by use, or in any other way, before the date of filing of the European patent application. For the purposes of this Article a written description may also take the form of a drawing. When a feature is shown solely in a drawing without any other clarifying description a careful check should be made to establish whether the mere diagrammatic representation enables a person skilled in the art to derive a practical technical teaching therefrom. It would be impossible to lay down general rules as to how this should be done because the reply in each case will depend on the knowledge of the person skilled in the art and of the way in which the feature is shown in the drawing. Thus if a drawing is specifically devoted to disclosing a certain feature or if that feature is systematically included in a number of drawings a person skilled in the art will see it as an important item of technical information even if the illustration is unaccompanied by a verbal description or numerical information. If on the other hand, the feature is shown in the drawing merely as an ancillary element of a complicated device a person skilled in the art will sometimes be unable to elicit useful technical information from the drawing, at least without the information supplied in the newly filed patent application.

5. The Board is of the opinion that Figure 9 of the aforementioned US patent is one of the latter cases. It shows a Venturi tube surmounted by a chamber terminating in the drawing in a wavy line to indicate that it is only a partial illustration. The portion of the chamber shown comprises a frustoconical tube held in place by lateral supports and with a serrated base situated where the Venturi tube met the container, the tube tapering slightly towards the upper end. A nozzle is positioned vertically within the Venturi tube. The space between the frustoconical tube and the walls of the container is largely filled with particles. In addition, particles are shown widely dispersed, mainly above the tube but also on its sides. It is evident from the chain-dotted lines radiating from the tube, as from the two vertical arrows above it to indicate a continuation of the flow, that the function of the tube is to convey a certain substance.

6. The Examining Division thought it possible to derive from Figure 9 specific dimensions for the height and diameter of the central cylindrical portion of the Venturi tube not stated elsewhere in the description. This is going beyond the information actually conveyed. The text of the US patent describes Figure 9 as a cut-away view of the coating apparatus shown in Figure 8, the latter being a diagrammatic representation of an embodiment of the invention. One must thus conclude that Figure 9 in turn is a diagrammatic representation of the Venturi tube region. The specific description of the US patent contains no definition or interpretation of the words "diagrammatic representation" giving cause to depart from the meaning the term generally conveys. "La schématisation met en oeuvre la factulté de jugement ou de discernement du lecteur, et non sa mémoire. Une représentation schématique montre la disposition générale d'un objet. Une forme schématique est réduite aux caractères essentiels" (Representation in diagrammatic form calls upon a person's ability to judge or discern, not on his memory. A diagrammatic representation shows the general design of an object. A diagrammatic form is one reduced to essential features) - See Grand Larousse Encyclopédique, 1964. These definitions do not differ substantially from those given in the main English-language reference works, namely the Oxford English Dictionary 1969, Webster's Third New International Dictionary 1976, and the New Encyclopedia Britannica 1977. It results that a diagrammatic representation is confined to the essential features of the object shown and that it allows considerable latitude in the object's practical realisation. However the mere diagrammatic representation of a principle that still has to be worked out in detail is not the same for a person skilled in the art as precise instructions equivalent to a technical teaching.

7. In conclusion the Board considers that by referring to figures as diagrammatic representations a writer helps a person skilled in the art to understand better what is described elsewhere. However, illustrations - useful as they often are for a better understanding of the subject-matter described - cannot be regarded as exact representations of this subject-matter. No one skilled in the art would conceive of measuring a diagram in order reliably to determine the dimensions of the object shown. Dimensions obtained solely by measurements carried out on a diagrammatic representation forming part of a document do not constitute part of the disclosure and cannot, therefore, be regarded as complementing the teaching contained in the description. Thus Figure 9 does not teach that the cylindrical portion of the Venturi tube must have a height greater than 0.5 d and less than 0.66 d.

8. Therefore, since the US patent cited does not disclose a device for introducing a flow of gas into granulators or coating apparatus of the spouted-bed type having all the features referred to in the claim of the application, the subject-matter of the latter is novel. As a result it is no longer necessary when considering the matter of novelty to deal with the other argument put forward by the appellants to the effect that the type of apparatus used following the US patent would not allow a spouted bed to be produced.

9. Consequently the objection to patentability raised by the Examining Division is baseless and the decision must be set aside. There is no indication in the examination dossier that the Examining Division pronounced on any aspect other than novelty. In order not to deprive the applicants of their right to have any findings reviewed the Board considers it appropriate to remit the case to the Examining Division under Article 111(1) EPC for further prosecution.