T 1033/14 07-10-2019

I. The appeal was lodged against the decision of the opposition division posted on 19 February 2014 revoking European patent No. 1 486 317.

II. During the opposition proceedings, the opponents had raised the grounds for opposition according to Article 100(b) and Article 100(a) EPC 1973 in combination with Article 54(1) or Article 56 EPC 1973 (lack of novelty and lack of inventive step).

III. Oral proceedings were held before the board of appeal on 7 October 2019.

IV. The appellant (patent proprietor) requested that the decision under appeal be set aside and that the patent be maintained in amended form on the basis of the main request or first auxiliary request filed under cover of the letter dated 6 September 2019 or the second or third auxiliary requests filed under cover of the letter dated 30 August 2019.

V. The respondents I and II (opponents 1 and 2)requested that the appeal be dismissed.

VI. The documents referred to during the appeal proceedings included the following:

D1: EOS International User Meeting, 21 to 23 May 2003, Workshop: EOSINT P, slides of the presentation "Direct Manufacturing of Hearing Aid Shells: Process Control and Optimization" by Mr Mathey from Phonak Hearing Systems;

D1': German version of D1, filed on 8 August 2011;

D3: Kenneth G. Cooper: "Rapid Prototyping Technology", Dekker, New York, 2001, pages 1 to 11 and 118 to 137;

D4: DIN EN ISO 178, Kunststoffe - Bestimmung der Biegeeigenschaften;

D5: DIN EN ISO 527-1 und 527-2, Kunststoffe - Bestimmung der Zugeigenschaften;

D6: DIN EN ISO 1183-1, Plastics - Methods for determining the density of non-cellular plastics;

D8: Beaman et al.: "A New Direction in Manufacturing", Kluwer, Dordrecht, 1997, pages 226 to 243;

D9: Nelson et al.: "Improvements in SLS Part Accuracy", SFF Proceedings, September 1995, pages 159 to 169;

D13: US 5,659,478;

D21: A. Gebhardt: "Rapid prototyping: Werkzeuge für die schnelle Produktentstehung", Carl Hanser Verlag München Wien, 2**(nd) edition 2000, pages 206 to 207.

VII. Claim 1 according to the main request reads as follows:

"A method for improving production parts (94), in particular aerospace production parts, produced from a rapid prototyping machine (70), wherein the rapid prototyping machine (70) makes use of a rapid prototyping material (74), a set of input data (42, 44) and an information set (50, 52, 54) having information pertaining to manufacturing factors involved in a previous build run of a production part, the method comprising:

executing a build run (58) that produces output components, comparing said output components to said set of input data (42, 44) to produce a resultant data set, said resultant data set including deviations between said set of input data (42, 44) and said output components (94, 96), incorporating said resultant data set into said information set, and tailoring (48) said information set to reduce said deviations between said set of input data (42, 44) and said output components (94, 96) as compared to at least one previous build run, characterized in that the output components include a combination of at least one production part (94) and at least one iterative improvement specimen (96), wherein said iterative improvement specimens (96) include one of Z-tensile arrays, density cubes, dimensional pyramids, flexural samples, and combinations thereof, and wherein the at least one production part and the at least one iterative improvement specimen are compared to said set of input data to produce the resultant data set."

VIII. The arguments of the appellant in the written and oral proceedings can be summarised as follows:

Added subject-matter and extension of scope

Claim 1 of the main request was based on original claims 1 and 5. The additional feature of comparing the production part and the iterative improvement specimen to the set of input data was originally disclosed in paragraph [0006] of the application as filed. It made explicit in the claim what was implicit before. Adding this feature to the claim limited the extent of protection. Moreover, the description according to the main request was unamended compared to the patent specification. Consequently, the main request was in line with the requirements of Article 123(2) and (3) EPC.

Sufficiency of disclosure

The patent disclosed one way of carrying out the invention. In particular, paragraph [0026] indicated the machine to be used; the improvement of the production parts was explained in detail in Table 1 and paragraph [0038]. Thus, the relevant parameters were defined, the skilled person only had to adjust them in order to reduce possible deviations. Consequently, the disclosure of the claimed invention was sufficient.

Inventive step

It was contested that documents D1 and D1' were made available to the public before the priority date of the patent. Moreover, even under the assumption that they belonged to the state of the art, their content could not render obvious the subject-matter of claim 1 of the main request. Documents D1' or D1 contained two separate sections (see e.g. D1', slides relating to "Prozess Kontrolle" and "Prozess Optimierung"), neither of them disclosed the claimed design of the iterative improvement specimen (distinguishing feature (a)) or the aspect of comparing the production part and the iterative improvement specimen to the set of input data (distinguishing feature (b)). The latter feature had the technical effect of further improving the rapid prototyping process for manufacturing production parts. Neither document D1' nor any other prior art on file disclosed or suggested that the production part and the iterative improvement specimen manufactured in one build run were compared to the set of input data. In particular, this applied to slide "Prozess Optimierung (4)" of document D1'. The claimed method related to improving the conditions during the production in a steady state. In contrast, document D21 referred to the calibration of the rapid prototyping machine before starting production. The fact that specific types of iterative improvement specimens were used in the method of claim 1 allowed for a reliable testing of certain properties. Documents D3, D8, D9 or D13, which the respondents had used as alternative starting points, were not suitable for serving as closest prior art. Documents D8 or D9 did not disclose the manufacturing of production parts. In particular, their teaching concerned the calibration of the machine and did not mention iterative improvement specimens. Document D13 was directed to the improvement of the part design cycle by modifying the model itself (see D13, top of column 6); it did not relate to a production process. Similarly, document D3 did not concern final products in the sense of the patent (see paragraphs [0008] and [0009] of the patent specification) but the prototyping of parts. It could not suggest that the production part and the iterative improvement specimen produced in one build run were compared to the set of input data, as defined in distinguishing feature (b). In view of the content of the documents on file, the subject-matter of claim 1 was based on an inventive step.

IX. The arguments of the respondents were essentially as follows:

Added subject-matter and extension of scope

Amended claim 1 constituted a generalisation of the detailed disclosure in paragraph [0006] of the application as filed. In particular, this paragraph specified that the input data included desired dimensions and desired material characteristics, that the information set included a thermal analysis of a parts bed and fabricated parts, material characteristics of the rapid prototyping material, and/or build parameters, all of which were from previous build runs, known values, and/or computed values. This specific disclosure was unduly generalised in amended claim 1, which referred to unspecified input data and an information set pertaining to manufacturing factors involved in a previous build run. It was also noted that the wording of original paragraph [0006] was directed to a plurality of build runs while the claim required only one build run. Respondent II added that the amendment of original paragraph [0006] during the examination proceedings had shifted the scope of the claims, which was contrary to Article 123(3) EPC.

Sufficiency of disclosure

In claim 1 the input data were not specified; it was therefore not clear what was compared to what. Also the number of measurements was not defined. The claim was broad and unspecific. The object of the patent was to produce parts which were far superior to the prior art. It was not apparent how this could be achieved in only one build run. The patent did not contain any explanation in that respect. Moreover, the list of parameters given in Table 1 was not exhaustive. The skilled person was not able to reproduce the invention based on the information given in the patent. It was was not taught which parameter had to be changed and how this had to be done, although this was the crucial step in the claimed method. In particular, it was not explained how the measurements on the production parts and the iterative improvement specimens and possible deviation from the data set were used in the subsequent steps. It had to be borne in mind that rapid prototyping was a complicated process, as shown in documents D8 and D9.

Inventive step

Documents D1 and D1' were made available to the public and therefore belonged to the state of the art. Document D1' (or D1, which has the same content), disclosed the manufacturing of a combination of production parts and iterative improvement specimens by rapid prototyping (see D1', slides "Prozess Charakteristiken (1)" and "Prozess Kontrolle (2)"). In the process of document D1', the iterative improvement specimens were compared to the input data set (see D1', slide "Prozess Kontrolle (3)") in order to establish recommendations for the next build run (see D1', right part of the table on slide "Prozess Kontrolle (4)"). Finally, the temperature profile based on a "Jobreport-File" in the context of a wall thickness optimisation (see D1', slide "Prozess Optimierung (1)"), as could be seen in slide "Prozess Optimierung (4)" of document D1'. Thus, the subject-matter of claim 1 differed from document D1' in the shape of the iterative improvement specimens (distinguishing feature (a)) and in the fact that not only the iterative improvement specimens were compared to the set of input data but the at least one production part and the at least one iterative improvement specimen (distinguishing feature (b)).

The problem to be solved by distinguishing feature (b) was to further improve the optimisation of the production parts. Document D21 served as evidence for the common general knowledge of the person skilled in the field of rapid prototyping. On page 207 of document D21, it was stated that rapid prototyping processes were strongly dependent on their calibration and that the model had to be (at least partly) built several times in order to achieve optimal results. This was also the message of document D3 (see Figure 1.1). In combination with document D1, the teaching of document D21 (or D3) therefore was that the iterative improvement specimen and the production part, which differed from each other in their shape, had to be compared to the set of input data. This led to a high quality production part with a complex and unique geometry in less time with fewer test runs for calibration. It was noted that also Table 1 of the patent in suit dealt with calibration. Therefore, distinguishing feature (b) did not justify the presence of an inventive step.

Regarding distinguishing feature (a) relating to the design of the iterative improvement specimens, the shape of the test specimens was defined in existing standards, such as document D4 for measuring the flexural strength and document D5 for measuring the tensile strength. According to standard document D6 (see point 5.1.3), no specific shape was required for measuring the density. In view of the fact that test specimens were standardised, it was obvious to use a standard shape for the iterative improvement specimens of claim 1. Hence, also distinguishing feature (a) was obvious to the skilled person.

Moreover, documents D3, D8, D9, and D13 could serve as alternative starting points for the assessment of inventive step. Document D3 showed the rapid prototyping cycle on page 5 (see Figure 1.1), which indicated that the production parts were compared with the set of input data (see also D3, page 6, fifth paragraph and chapter 1.5). Claim 1 differed from this disclosure in that a test specimen was produced in parallel to the production part. However, this was rendered obvious by document D1 which disclosed the parallel production of an iterative improvement specimen and a production part. Hence, the combination of documents D3 and D1 disclosed all features of present claim 1.

Compared with document D8 (see chapters 6.5 and 6.5.3, in particular pages 226, 231 to 233 as well as Figure 6.50), the subject-matter of claim 1 differed in that a production part and an iterative improvement specimen, which were produced in one build run, were compared to the input data set. The problem to be solved by this distinguishing feature (b) was to improve the efficiency and accuracy of the optimisation of the production parts. The skilled person would deduce from the last paragraph of page 233 of document D8 that the process could be improved by measuring test parts and production parts. It was clear to him that not all of the process parameters could be optimised using the test specimen of Figure 6.50 of document D8. Against this background, the solution consisting in comparing not only the iterative improvement specimen but also the production part to the input data was obvious to the person skilled in the art.

According to document D9 (see first paragraph of page 165 and chapter 3.2, in particular Figure 5 on page 166), the production parts and the test specimens of Figure 5 were produced in separate build runs during the optimisation of the process. In view of this prior art, the problem to be solved by the subject-matter of claim 1 was to improve the efficiency of the process optimisation. Starting from document D9, it was obvious to the skilled person that this problem could be solved by comparing the iterative improvement specimen and the production part, which were simultaneously produced in one build run, to the input data. In this context, it was noted that claim 1 did not provide a definition of the term "production part".

Document D13 (see column 1, lines 1 to 5, column 2, lines 63 to 67, column 6, lines 6 and 52 to 67) essentially disclosed the production of a plurality of production parts in an iterative improvement process. The subject-matter of claim 1 differed from this method in that a production part and an iterative improvement specimen were produced in one build run and were then compared to the input data set. However, in view of the fact that some of the production parts of document D13 had to de destroyed when testing their mechanical properties, it was obvious that simultaneously producing iterative improvement specimens and production parts in one build run and using the iterative improvement specimens for the mechanical testing avoided the destruction of good production parts for testing purposes. This increased the overall efficiency of the iterative improvement process. Hence, for the skilled person, the subject-matter of claim 1 was not inventive over document D13.