T 0536/88 (Dust-tight folding carton) of 14.1.1991

Summary of Facts and Submissions

I. The respondents are the proprietors of European patent No. 0 106 215 (application No. 83 109 529.4) granted on 3 September 1986.

II. The appellants filed an opposition against the European patent on the grounds that the sole claim was not inventive in view of:

D1: DE-A-2 845 720

After expiry of the opposition period, in a letter dated 26 January 1988 they cited further documents:

D2: DE-U-8 210 781.5

D3: US-A-2 501 852

D2 is cited and acknowledged in the description of the contested patent as the closest prior art.

III. In a decision dated 28 September 1988 the Opposition Division rejected the opposition, explaining that D2 and D3 were considered as having been submitted out of time. The opponents had given no reason for their failure to submit these documents in time, and in any case they were immaterial to the decision on inventive step, since even a combination of the features from the two documents would not result in the subject-matter of the claim of the contested patent. In particular, the characterising feature indicating that the stamped embossment on one of the closure flaps projects inwards was missing. D2 and D3 were therefore disregarded pursuant to Article 114(2) EPC.

IV. On 20 October 1988 the appellants lodged an appeal against this decision and paid the appeal fee. The grounds of appeal were received on 16 January 1989. In the course of the appeal proceedings the appellants cited in addition:

D4: FR-A-1 092 342,

D5: DE-A-2 260 766

V. After despatch of a communication accompanying the summons to oral proceedings, as provided for in Article 11(2) of the Rules of Procedure of the Boards of Appeal, oral proceedings were held on 14 January 1991 at which the appellants made the following requests:

(1) that the contested decision be set aside and the case remitted to the department of first instance;

(2) that the appeal fee be reimbursed because of a substantial procedural violation;

(3) that the contested decision be set aside and European patent No. 106 215 revoked.

The appellants argued essentially as follows:

(a) In the contested decision it was stated that D2 had only been cited after the opposition period had expired and hence out of time for the purposes of Article 114(2) EPC, whereas it could be seen from the first page of the patent specification that it had already been cited at the examination stage. Furthermore, it was apparent from the patent specification that the claim had always been delimited from this document. D2 had thus been introduced into the proceedings before expiry of the opposition period and was important to the decision on inventive step. The failure to take D2 into consideration in the opposition proceedings was therefore a substantial procedural violation.

Since this, the closest prior art, had not been reviewed and the invention therefore not properly assessed for inventive step, the case should be remitted to the department of first instance to allow the matter to be dealt with at two instances before the European Patent Office.

(b) The subject-matter of the sole claim did not involve an inventive step with regard to the prior art according to D2 and D4.

The contested patent was based on D2 which is described in the claim's pre-characterising portion. In the case of this known folding carton, the fact that the free longitudinal edge of the top closure flap juts out above the unembossed flap which lies immediately underneath it, the height of the projection corresponding to the full thickness of the board, is cited as a disadvantage. This poses the risk of top flaps being ripped open when the cartons are stacked on pallets or shelves, particularly when filled unit packs are pushed on top of others. The contested patent therefore deals with the problem of making the cartons easier to handle. The main advantage it is sought to achieve with the new folding carton consists in its having a flat bottom and/or top, leaving the flap which lies on top in each case less vulnerable than the previously known embodiment.

Faced with the problem of improving a typical carton, featuring in particular shortened closure flaps, in such a way as to eliminate projecting edges on its bottom or top surface, the skilled person would obviously recognise that he could eliminate such an edge by designing a flat bottom and top surface. To solve this problem he would make use of the known prior art and look for suggestions on how to make adjacent and partly overlapping flaps with a flat outer flap or surface.

Figure 18 in D4 would suggest to him the possibility of making the surface of partly overlapping flaps flat by means of a stamped embossment projecting upwards and outwards, the height of the projection corresponding to the thickness of the board.

On the basis of his expert knowledge and this suggestion, the skilled person would realise that he could obtain flat bottom and top surfaces by making the stamped embossment on the flap according to D2 project inwards instead of outwards, and the height of the projection correspond to the thickness of the board.

(c) But even relying on common technical knowledge alone the solution to the problem addressed by the contested patent was obvious. The skilled person would be well aware that to produce a flat top surface in the case of two partly overlapping strips of material lying one on top of the other a step would have to be provided whose height corresponds to the thickness of the material. Applied to the folding carton known from D2, this knowledge would immediately tell the skilled person to make the stamped embossment project inwards instead of outwards.

VI. The respondents requested that the appeal be dismissed and the granted patent maintained without amendment.

The sole claim reads as follows:

"A dust-tight folding carton, the bottom and/or top of which is/are formed by two closure flaps (3, 4) hingedly connected to the front and rear wall panels (1, 2) and overlapping only partly, and by two dust flaps (7) hingedly connected to the side walls (5, 6), wherein only one (4) of the two closure flaps (3, 4) comprises on the overlapping section a stamped embossment (9) along a straight line (8) at which the other closure flap (3) ends, at the same position the dust flaps (7) comprise a stamped embossment (10) projecting inwards and also extending along a straight line (11), and wherein one closure flap (4) is positioned between the other closure flap (3) and said dust flaps (7), characterised in that the stamped embossment (9) of said one closure flap (4) projects inwards and mates with the stamped embossment (10) of the two dust flaps (7)."

The respondents submit that:

(a) It is clear from the remarks under point 12.2(e) to (h) of the contested decision that the Opposition Division scrutinised the two subsequently cited documents de facto for possible prejudice to novelty and relevance for the assessment of inventive step. The statement under point 12(i) that these documents had not been taken into consideration does not correspond to the facts and is of a purely formal nature.

A remittal of the case to the Opposition Division so that D2 and D3 can be examined at two instances in order to ensure that the appellants are not deprived of a possibility of subsequent review, would therefore be unjust.

(b) Neither the feature according to the pre-characterising portion indicating that the two closure flaps only partly overlap nor the characterising portion of the claim are contained in D4. How a skilled person without using his own inventive ability could have arrived at the claim's subject-matter by transferring features from D4 to a folding carton according to D2 is therefore not apparent.

(c) No suggestion along the lines of the solution as described in the claim is evident from the prior art as a whole. All the documents cited by the appellants, D1, D3, D4 and D5, pointed the skilled person in the same direction, i.e. towards an outside closure flap extending across the whole width of the carton.

Reasons for the Decision

1. The appeal complies with Articles 106 to 108 and Rules 1(1) and 64 EPC and is therefore admissible.

2. The appellants' requests for reimbursement of the appeal fee and remittal of the case to the department of first instance

2.1 The view expressed in the contested decision that D2, first introduced in the opponents' arguments after expiry of the opposition period, must be deemed not to have been submitted in due time cannot be endorsed. D2 is cited and acknowledged in the contested patent as the closest prior art; it is referred to in the claim's pre-characterising portion and forms the basis on which the technical problem set out in the contested patent's description was formulated. A knowledge of the essential elements of this document is thus a prerequisite for a correct understanding of the invention according to the contested patent and for this reason cannot be disregarded when assessing patentability.

The same applies to any material documents cited in the patent specification which do not comprise the closest prior art but whose contents are nevertheless important for understanding the problem underlying the invention within the meaning of Rule 27(1)(c) EPC.

It follows that in the present case D2 forms part of the content of the patent specification and is thus automatically admitted to opposition or opposition appeal proceedings.

2.2 The Board has compared this interpretation with previous decisions concerning similar points of law and concluded that it is not at variance with their findings.

Decision T 105/83 dated 9 July 1984 (unpublished) states under point 3 of the Reasons for the Decision:

"The cited document (3) was mentioned in the search report and incorporated in the patent specification. Although it was not considered material to the proceedings before the Opposition Division, the document was cited in the grounds of appeal and sufficiently discussed. There was no failure to submit it in due time within the meaning of Article 114(2) EPC."

In Decision T 198/88 dated 3 August 1989 (OJ EPO 1991, 254) the Board takes the view that opposition is not part of the grant procedure. For this reason a document cited and acknowledged in the contested European patent is not automatically scrutinised in opposition or opposition appeal proceedings if not mentioned within the opposition period.

That case differs from the present one in that the document in question did not relate to the prior art with reference to which the problem set out in the description was formulated or which was otherwise necessary for understanding the difficulties to be resolved by the invention and hence the invention itself. The problem had in fact been formulated on the basis of uncorroborated prior art which the Board itself had used for the assessment of inventive step, even though this prior art had apparently not been mentioned within the opposition period (see points 4.1, 4.2). The principle set out in that decision that a document cited and acknowledged in the contested patent is not automatically admitted in opposition or opposition appeal proceedings thus did not relate to a document acknowledged in the contested patent as the closest prior art or to other relevant documents used to define and elucidate the technical problem set out in the description.

2.3 The Opposition Division stated under point 12.2(i) of the contested decision that it was invoking the option under Article 114(2) EPC of disregarding D2, deemed not to have been submitted in due time, and D3, likewise not submitted in due time. Nevertheless, under point 12.2(e) to (h) it considered their relevance de facto and concluded that neither individually nor in combination did the documents prejudice maintenance of the contested patent as granted. In point 12.2(e) of the Reasons for the Decision the Opposition Division explains why it reached this conclusion, pointing out that the claim's subject-matter was not known from D2 and D3. This followed from the fact that neither of the documents described a closure flap with a stamped embossment projecting inwards (point 12.2(g)). Furthermore, for the purposes of assessing inventive step under point 12.2(f) and (g) the Division mosaicked features from D2 and D3 and established that a combination of the two documents would not give rise to all the features of the claim.

2.4 The appellants' submission that the claim's subject-matter was obvious from a combination of D2 and D3 was therefore taken into consideration in the contested decision and in the Opposition Division's view refuted. Insofar as the appellants based their submission regarding lack of inventive step exclusively on D1, this was likewise taken into consideration and refuted in the contested decision. Since the contested decision thus de facto went into all the appellants' arguments, the Opposition Division did not contravene Rule 68(2) EPC, i.e. by failing to provide reasons, and so there has been no procedural violation.

2.5 The requested reimbursement of the appeal fee is therefore not justified on the facts and is in any case ruled out as the requirement of Rule 67 EPC that the appeal be successful has not been met.

2.6 The Board sees no grounds for remitting the case to the Opposition Division to allow examination of D2 at two instances and thereby ensure that the appellants are not deprived of a possibility of subsequent review, since as explained above the document has already been taken into consideration de facto by the Opposition Division.

2.7 For these reasons the appellants' requests in issue here had to be rejected.

The appellants' request for revocation of the patent

3. Having examined the facts of its own motion pursuant to Article 114(1) EPC, the Board has concluded that D3 and D5 are not material to the issue of the patentability of the contested patent's subject-matter and that it can thus, acting within the limits of its discretionary powers pursuant to Article 114(2) EPC, disregard these documents.

This conclusion does not require any further comments (see T 198/88, loc. cit., point 2.2).

With regard to D4, submitted out of time, the Board has concluded from an examination of the facts which it carried out of its own motion that this document must be taken into account because it is essential for assessment of the invention, even if - as set out below - examining said document does not alter the decision.

ORDER

For these reasons it is decided that:

1. The appeal is dismissed.

2. The requests for remittal of the case to the first instance and reimbursement of the appeal fee are rejected.