T 2305/14 12-02-2020

1. Procedural matters

With letter dated 10 July 2019 the appellants/p stated that they would not be attending the oral proceedings scheduled before the board, which thus took place in the appellants/p's absence in accordance with Rule 71(2) EPC 1973.

According to Article 15(3) and (6) RPBA 2020, the board is not "obliged to delay any step in the proceedings, including its decision, by reason only of the absence at the oral proceedings of a party duly summoned who may then be treated as relying only on its written case" and has to "ensure that each case is ready for decision at the conclusion of the oral proceedings, unless there are special reasons to the contrary".

The appellants/p had argued and explained in writing why they considered the claimed subject-matter not to extend beyond the parent application as filed and the claimed invention to be suffi­ciently disclosed. By not attending the oral pro­ceed­ings before the board the appellants/p gave up the op­por­tunity to present their case orally in these respects and could thus be treated as relying only on their written submissions.

The board's decision, which hinges on the issues of extension beyond the parent application as filed and suf­ficiency of the disclosure (see below), is therefore in confor­mity with the requirements of Article 113(1) EPC 1973 that the decisions of the EPO may only be based on grounds or evidence on which the parties concerned have had an opportunity to present their comments.

Accordingly, the case was ready for decision at the conclusion of the oral proceedings in accordance with Article 15(6) RPBA 2020.

2. Main request and first to third auxiliary requests - amendments

2.1 In the decision under appeal the opposition division held that the subject-matter of the feature relating to each streamer positioning device having a wing used to control its lateral position did not extend beyond the content of the parent application (see point 3.4.1 of the Reasons).

2.2 The appellant/o argued that the above feature extended beyond the parent application since vertical and horizontal control had always been disclosed together in the parent application.

2.3 It is established jurisprudence that an amendment based on the extraction of an isolated feature from a set of features originally disclosed only in combination is normally not allowable. Such an intermediate generaliza­tion might only be justified in the absence of any functional or structural relation­ship among the fea­tures of the specific combination (see Case Law of the Boards of Appeal of the EPO, 9th edition, section II.E.1.9)

2.4 In the present case respective claim 1 of the main request and the first to third auxiliary requests contains the feature relating to "each of the streamer positioning devices having a wing used to control the lateral posi­tion of the streamer positioning device" (see features (a) and (a)2, respectively), which constitutes an amend­­ment in relation to original claim 1 of the parent appli­cation.

It has to be examined whether this amendment is directly and unambiguously derivable from the parent application as filed.

2.5 The board notes first that - as pointed out by the appel­lant/o - the parent application only contains a detailed description of one type of streamer positioning devices ("birds"), namely a bird 18 having two inde­pendently movable wings 28 connected to rotatable shafts 32 that are rotated by wing motors 34 and that allow the orientation of the wings 28 with respect to the bird body 30 to be changed (see Figures 2 and 3 and page 9, third paragraph - page 10, third paragraph of the parent application)­.

The lateral and vertical position of the bird 18 is controlled by adjusting the splay angle (i. e. the difference between the angles of the wings 28) and the common angle of the wings 28, which yield the desired roll movement of the bird and motion perpendicular to its wings, respectively (see page 18, para­graph 2 of the parent application).

The control of the lateral and vertical position being thus intimately linked for this device, it is not possi­ble to control exclusively its lateral position.

2.6 The appellants/p were of the opinion that a variety of types of bird were mentioned in the parent application and that there was no need to limit the claim to a single type of bird described in detail. Moreover, it was stated in the parent application that it was merely preferable that the birds were both vertically and horizontally steerable.

The passages in the parent application cited by the appellants/p read as follows (page 6, lines 2-3; page 9, paragraph 2):

"Preferably the birds 18 are both vertically and horizontally steerable."

"Figure 2 shows a type of bird 18 that is capable of controlling the position of seismic streamers 12 in both the vertical and horizontal directions. A bird 18 of this type is also disclosed in our PCT International Application No. WO 98/28636. While a number of alternative designs for the vertical and horizontal steerable birds 18 are possible, including those utilizing one full-moving wing with ailerons, three full-moving wings, and four full-moving wings, the independent two-wing principal is, conceptually, the simplest and most robust design."

All three alternative bird designs mentioned in the second passage above (one full-moving wing with ailerons, three full-moving wings, and four full-moving wings) are referred to as those for "vertical and horizontal steerable birds". Moreover, in the absence of further details concerning the functioning of these designs there is no disclosure that one of the designs allows the exclusive control of the lateral posi­tion of the bird, either.

Furthermore, merely stating that it was preferable that the birds were both vertically and horizontally steerable does not constitute any technical teaching of a bird that is steerable in only one of these directions.

Finally, none of the alternative bird designs merely has a single wing as claimed. Rather, they either have more wings or a single wing supplemented by ailerons.

2.7 In view of the above, the amendment mentioned under point 2.4 amounts to an intermediate generalization which is not directly and unambiguously derivable from the parent application as filed.

Consequently, respective claim 1 of the main request and the first to third auxiliary requests contains subject-matter extending beyond the content of the parent application as filed (Articles 76(1) and 100(c) EPC 1973).

3. Fourth to seventh auxiliary requests - sufficiency of the disclosure

3.1 In the decision under appeal the opposition division held that the invention was sufficiently disclosed in the patent (see point 3.2 of the Reasons).

3.2 It is established jurisprudence of the Boards of Appeal to consider the disclosure of an invention to be only sufficient it it allows the invention to be performed in the whole range claimed (see Case Law of the Boards of Appeal of the EPO, 9th edition 2019, sections II.C.5.4).

3.3 In the present case, respective claim 1 of the fourth to seventh auxiliary requests re­lates to a method of controlling streamer positioning devices using a control system distributed between a global control system and a local control system loca­ted on each streamer po­si­tioning device. In particular, it is speci­fied in these claims that each of the stream­er posi­tioning de­vices has a wing which is used to control its verti­cal and lateral position (features (a)4 and (a)5, respec­tively) and that the local control system is used to adjust the angle of the wing (fea­tures (c) and (c)1, respectively).

It is therefore claimed in each respective claim that each streamer positioning device has a single wing which is used to control the vertical and lateral position of the streamer positioning device. This is common ground between the parties.

It has to be considered whether the patent as a whole provides sufficient information for the skilled person to carry out - using common general knowledge - such a method of controlling streamer positioning devices, where each streamer positioning device has a single wing which is used to control its vertical and lateral position.

3.4 Corresponding to the disclosure in the parent application mentioned under point 2.5 above, the patent specification only contains a detailed description of one type of streamer position­ing devices having two independently movable wings (see Figures 2 and 3 and para­graphs [0024] to [0027]). Moreover, the passage of the parent application men­tioned under point 2.6 above concerning alternative bird designs is also contained in the contested patent (see paragraph [0023]). These alternative bird designs exhibit either more wings than the preferred two-wing design, namely three or four wings, or "one full-moving wing" albeit with "ailerons". As the skilled person knows, the latter are secondary wings or fins, which usually form part of the trailing edge of the primary wing and are used for controlling the roll angle of the device.

Hence, neither the bird design described in detail nor the disclosed alternative designs exhibit only a single wing. In particular, the alternative "one full-moving wing" design comprises said ailerons which are essential in providing control of the roll angle of the bird and thus, together with the full-moving wing, of its vertical and lateral motion.

Accordingly, the patent specifi­ca­tion does not contain any explicit instruc­tions to the skilled person on working the invention with birds having only a single wing which is used to control its vertical and lateral position.

3.5 The appellants/p argued that the skilled person would be aware of rudders used for controlling the lateral position of a marine vessel and have no difficulty in carrying out the invention across the full breadth of the claims.

However, the use of birds attached to streamer cables for providing - like rudders - lateral position control of the cables is neither described nor hinted at in the patent specification. Furthermore, there is no evidence on file showing that this is part of the common general knowledge of the skilled person, either. Rather, it appears from the description of the prior art in the patent specification (see paragraphs [0004] and [0005] cited in part below) that birds were primar­ily known for provid­ing depth control in order to keep the stream­ers at a constant depth and that the addi­tion­al control of the lateral position provided further benefits (e. g. reducing the chance of tangling adjacent streamers):

"The streamers are typically towed at a constant depth of approximately ten meters, in order to facilitate the removal of undesired 'ghost' reflections from the surface of the water. To keep the streamers at this constant depth, control devices known as 'birds', are typically attached at various points along each streamer between the deflector and the tail buoy [...] While the majority of birds used thus far have only controlled the depth of the streamers, additional benefits can be obtained by using properly controlled horizontal steerable birds [...] The benefits that can be obtained by using properly controlled horizontal steerable birds can include reducing horizontal out-of-posi­tion conditions that necessitate reacquiring seis­mic data in a particular area (i. e. in-fill shoot­ing), reducing the chance of tangling adjacent stream­ers, and reducing the time required to turn the seismic acquisition vessel when ending one pass and beginning another pass during a 3D seismic survey."

Moreover, even though it might be imagined that the wing of a bird, when used like a rudder, could in principle provide lateral position con­trol of the streamer cable it is obscure how the same wing could also pro­vide vertical position control of the streamer cable. It is in line with the disclosure in the patent speci­fi­cation and with the general understanding of the skilled person that there is only one control parameter for controlling the wing of a bird, namely its angle of orientation. Hence, it is not evident for the skilled person how the control of this single parameter could provide position control in two different directions, namely both lateral and vertical position control.

3.6 In view of the above, the board concludes that the patent does not disclose the invention as claimed accord­ing to any one of the ­fourth to seventh auxiliary requests in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art in the whole range claimed (Articles 83 and 100(b) EPC 1973).

4. Conclusion

Since the European patent contains subject-matter extend­ing beyond the content of the parent application as filed (main request and first to third auxiliary requests) and does not disclose the inven­tion in a manner suffi­ciently clear and complete for it to be carried out by a person skilled in the art (fourth to seventh auxil­iary requests), the patent has to be revoked (Article 101(3)(b) EPC and Article 111(1) EPC 1973).