Friday, 21 October 2016

T 2346/12 - Defined by flex modulus

In this opposition appeal, the appellant (patent proprietor) lodged an appeal against the decision revoking European patent No. 1 773 675.

In the appealed decision, the opposition division found that neither the main request (patent as granted) nor the auxiliary request met the requirements of Article 83 EPC.

Of particular interest in this case is that claim 1 defines a closure for sealing a container (...) characterised in that the outer wall surface (10) at the first wall edge (22) has a flex modulus of less than 3.95 N/mm", i.e., a characterisation by parameter.

This case shows the pitfalls of such type of characterization.

Namely, as argued by the\respondent (opponent), in the patent in suit apparently a new method for determining the flexibility with the new parameter "flex modulus" was developed, however without providing the adequate level of information for its implementation. 

Reasons for the Decision
1. Main Request - Sufficiency of disclosure, Article 83 EPC

1.1 The characterising part of a claim 1 has the following feature:

"the outer wall surface (10) at the first wall edge (22) has a flex modulus of less than 3.95 N/mm" (emphasis added by the Board).

1.2 Given that it is not immediately evident to the person skilled in the art what a flex modulus of a surface is, the appellant referred in this respect to the Case Law of the Boards of Appeal, 8**(th) edition 2016, II.A.6.3.1, third and fourth paragraphs, according to which the description can be used as the patent's "dictionary" to establish the meaning of terms used in claims.

1.3 According to the appellant the skilled person taking into consideration the information disclosed in paragraphs 31 to 34 of the patent would consider that the flex modulus of the closure's outer wall surface claimed in claim 1 is meant to be a measure for the flexibility of that wall, established by using for example a Lloyd Instruments LR 5K compression tester, which produces a graph of the deflection (mm) dependent on the force (N).

1.4 The Board follows the appellant in that this flex modulus is meant to be the parameter which defines the tendency of the closure's wall to bend and which is to be determined according to the compression test mentioned in paragraph 32 of the patent.

The Board notes thereby that it is well established in the art that the term "modulus" defines a coefficient that expresses numerically the degree to which a body or substance possesses a particular property, as for example tendency to bend.

1.5 It is further undisputed that the generally accepted parameter for determining the tendency to bend, i.e. the flexural capacity of a body or substance is the "flexural modulus" and is determined from the slope of a stress-strain curve, such as produced by a flexural standard test (e.g. ASTM D 790 (E7)) having units of force per area, such as the SI units N/mm**(2).

1.6 In the present case the flexibility of the closure's outer wall is, according to the appellant, not defined on the basis of the above-mentioned generally accepted parameter "flexural modulus" but on the basis of a new parameter, namely the "flex modulus", which corresponds to the gradient of the load-deflection plot of a compression test such as the one according to paragraph 32 of the patent.

1.7 According to the Case Law of the Boards of Appeal, 8**(th) edition, 2016, II.C.4.5, second paragraph, the purpose of a parameter contained in a claim is clearly to define an essential technical feature of the invention. Its significance in the present case is that it contributes to the solution of the technical problem underlying the invention. The method specified should therefore be consistent with the parameter and should produce consistent values, so that the skilled person will know, when he carries out the invention, whether what he produces will solve the problem or not.

In the present case the upper limit of 3,95 N/mm for the claimed flex modulus range intends to define that the closure's wall is easily deformable by hand, see paragraph 18 of the patent.

1.8 It is undisputed that there is no supporting evidence in which flexibility is expressed with a "flex modulus" parameter, said parameter being calculated according to the method mentioned in paragraph 32 of the patent.

1.9 In this respect the Board notes that nothing in the patent, let alone in paragraph 32, mentions anything resembling a gradient of the graph produced by this method. Further, as argued by the respondent, there is a lack of technical information at least in respect of the shape of the die to be used and to the direction of the compression load to be applied.

Whether the die has to be in the form of a plate, of a bar or has only a punctual contact with the outer wall of the closure is not mentioned. Paragraph 32 does not specify the form of the die's part coming into contact with the outer wall's surface.

As concerning the angle at which the compression force is to be applied, it is conceivable that in the compression test the direction of the force can be perpendicular to the outer wall's surface at the first wall edge, or perpendicular to a central longitudinal axis of a cylindrical closure.

1.10 In view of the above, the Board concludes that in these three aspects there is a fundamental lack of technical information concerning the determination of the parameter "flex modulus" claimed in claim 1 in the patent.

1.11 As a consequence, the Board considers that the main request does not comply with the requirements of Article 83 EPC.


For these reasons it is decided that:

The appeal is dismissed.

This decision T 2346/12 (pdf) has European Case Law Identifier: ECLI:EP:BA:2016:T234612.20160916 The file wrapper can be found here. Figure from the International publication of the A2 Pamphlet.


  1. That is what happens when an applicant patentee wants to be clever and brings in a new parameter.
    It is interesting to note that the examiner in charge was concerned about the "flex modulus" in N/mm, and not in N/mm², but he dropped his objection.

    The conclusion reached by the opposition division could have been reached by the examining division, and all the opposition procedure could have been avoided.....

    And at the time early certainty (of nothing) was not yet the buzz word....

  2. That is what happens when an applicant brings in a new parameter without a proper definition. A load/deflection parameter may well have been necessary, while trying to capture the "easy opening effect" for caps of various shapes. The fact that another parameter exists, having a confusingly similar name, does not make the choice of the applicant a wrong one. (Though it does not help either, if a skilled person is left obvious as to how the new parameter is to be interpreted.)