T 2589/12 16-11-2016

1. Applicable law

The application on which the opposed patent is based was filed on 4 June 2004. According to Article 7 of the Act revising the EPC of 29 November 2000 (OJ EPO 2007, Special edition No. 4, 217) and the Decision of the Administrative Council of 28 June 2001 on the transitional provisions under Article 7 of the Act revising the EPC of 29 November 2000 (OJ EPO 2007, Special edition No. 4, 219), Article 56 EPC 1973 applies in the present case.

2. Admissibility of document O5-bis and the arguments based thereon

Document O5 had been cited in the notice of opposition filed by the appellant, whereas document O5-bis was filed for the first time with the statement of grounds of appeal.

Document O5-bis is a U.S. application filed as a continuation (and not a continuation-in-part) of a PCT application, on entry into the U.S. national phase. Document O5 is the Canadian application based on the same PCT application. Therefore, documents O5 and O5-bis undoubtedly belong to the same patent family.

Document O5-bis could have been filed before the opposition division. However, there was no clear incentive to do so because the appellant was of the opinion that the disclosure of document O5 as such was sufficient for establishing a lack of novelty. The verdict of the opposition division made clear that the division had reached a different conclusion.

Therefore, the board considers that the filing of document O5-bis is a reaction to the discussion during the oral proceedings before the opposition division and to the decision taken by the opposition division.

When looking for documents strengthening its case, the opponent could reasonably be led to examine more closely the U.S. counterpart to the Canadian application O5. This is because under U.S. law there are specific requirements (such as the requirement to disclose the "best mode") which sometimes lead applicants to supply additional pieces of information related to the invention.

Incidentally, a document can be prima facie relevant without necessarily being more relevant than another document on file: relevance is an absolute rather than a relative criterion.

Having considered these circumstances, the board is unable to see an abuse of proceedings in the belated filing of document O5-bis.

Consequently, the board has decided to admit document O5-bis and the arguments based thereon.

3. Remittal to the opposition division

The admission of late-filed documents by a board of appeal may justify the remittal of the case to the opposition division, in order to offer two degrees of jurisdiction to the parties. However, under the EPC there is no absolute right to having all matters raised by two successive instances, and there may be good reasons not to remit a case.

Although more detailed in its disclosure, document O5-bis is very close to document O5, which has been examined by the opposition division. Its admission appears not to create a significantly different substantive situation and does not jeopardise the respondent's right to a fair trial.

The opponent would have weakened its case had it filed an inventive step objection (where differences have to be stated) based on a document which it considered to destroy the novelty of the claimed subject-matter (see decision T 131/01, point 3.1 of the reasons, OJ EPO 2003, 115).

A remittal, possibly followed by a fresh appeal, would probably have delayed the final decision by several years.

Having considered all the above, and in view of the duration of the grant and opposition proceedings so far (the application was filed in 2004) and of the right of the public to have a final decision on the merits of the case within a reasonable delay, the board has reached the conclusion that a remittal is not appropriate in the present case. Therefore, the respondent's request for a remittal is dismissed.

4. Main request

4.1 Claim interpretation: "nose portion"

Apart from its anatomical meaning, the term "nose" is often used to designate "a prominent or projecting part" or "the point or extremity of something" (Oxford English Dictionary).

The opposed patent does not define the term "nose portion" but contains several elements that may help clarify its meaning:

- the reference to a "nose portion of the lip" (paragraph [0057]) indicates that anatomical analogies should not be overstressed;

- in paragraph [0041] of the opposed patent it is said that the portion 15 (i.e. the end portion of the pin) of Figure 1 is referred to as nose portion:

FORMULA/TABLE/GRAPHIC

- in paragraph [0081] of the opposed patent "nose portion" is used as a synonym of "tip of the pin".

The skilled person considering these elements of disclosure would, therefore, reach the understanding that "nose portion" of the pin refers to the axial end or tip of the pin.

The question arises how this understanding can match with the feature according to which the "nose portion is provided on the pin between the sealing surface and the shoulder surface". As all the embodiments of the opposed patent have pins in which the shoulder surface delimits the tip of the pin and cannot be separated from it, this feature is understood to mean that the nose portion extends between the sealing surface and the shoulder surface.

4.2 Novelty over document O5-bis

It was undisputed that document O5-bis discloses features 1 to 11, 13-15, and 17-19 as defined above, point IV.IV. ).

There was, however, disagreement as to whether the document discloses features 12, 16, and 20+20'.

4.2.1 Feature 12

According to this feature the shoulder surface of the pin is in axial abutment with the corresponding shoulder surface of the box.

Document O5-bis shows both a pin 2 (Figure 1B) and a box 1 (Figure 1A) in an unassembled state.

FORMULA/TABLE/GRAPHIC

The penultimate sentence of paragraph [0044] of document O5-bis states: "When the tool joint is sufficiently torqued up, the external shoulder 9, as primary shoulder, abuts the box end face 4, whereas the pin nose section 29 [should read 19] is received by the box base section 20, with the internal shoulder 3, as secondary shoulder, abutting the pin end face 10."

The disclosure of this passage is clear: when pin and box are connected and sufficient torque is applied, the box end is in abutment with the external shoulder 9 and the pin end is in abutment with the internal shoulder.

The board cannot endorse the argument of the respondent according to which the conjunction "whereas" makes the passage unclear. It is quite clear that the drafter first presents what happens at the box end face and then turns to the pin end face. The adversative conjunction expresses this contrast.

Neither paragraph [0014] nor claim 1 contradict the assertion of paragraph [0044]. The distances 17 and 21 being what they are, it is clear that when the pin is screwed into the box, one of the ends abuts first, whereas a gap remains at the other end. This gap disappears when the screwing is continued.

This understanding also fits with paragraph [0047], the language of which ("first activated", "primary shoulder") suggests that that in the end both shoulders are activated.

Thus the board has reached the conclusion that document O5-bis discloses feature 12.

4.2.2 Feature 16

This feature requires the nose portion of the pin not to contact the portion of the box facing it.

No clear conclusion can be drawn from Figures 1A and 1B of document O5-bis. It is possible, but not certain that an assembly of the pin 2 and the box 1 would lead to a contact between contact surface 13 and the nose portion of the pin. However, there is no direct and unambiguous disclosure that there is no contact.

Therefore, the board has reached the conclusion that document O5-bis does not unambiguously disclose feature 16.

4.2.3 Features 20+20'

According to this combination of features the existence of the taper of the sealing surface of the pin involves on the pin a discontinuity of surface between the sealing surface and an outer surface of said nose portion.

Figure 1B of document O5-bis discloses the existence of a discontinuous transition from the tapered surface 15 to the nose portion of the pin:

FORMULA/TABLE/GRAPHIC

Detail of Figure 1B of document O5-bis

The contrary arguments based on the artistic freedom of the draughtsman have not persuaded the board. It would have been easier for the draughtsman to extend the slope of surface 15 until the end of the pin. There are, however, good technical reasons not to provide such an extension, because this would result in the tip having a smaller diameter and, therefore, a reduced rigidity.

The fact that the dashed-dotted line intersects the pin at the very point of transition from the conical part of the pin to its cylindrical part appears not to be fortuitous. The board was not persuaded by the respondent's argument that the dashed-dotted line only indicated the axial position of the apexes of the box. As a matter of fact, references 13 and 14 do not indicate apexes but contact surfaces; it is not obvious that the intersection between the dashed-dotted lines and those surfaces occurs at the apexes of the latter.

Incidentally, the board cannot confirm the assertion of the respondent according to which the slopes of surfaces 15 and 16 shown in Figure 1B contrast with the angular values given in the description. The slope of surface 15 measured from the drawings (about 12.1°) is within the ranges specified in paragraph [0035], i.e. between 18.4° (1:3) and 11.3° (1:5).

It is true that the "straight conical surface" 15 appears not to be completely straight in Figure 1B, but this cannot alter the fact that the skilled person would note the discontinuity between the surface 15 and the cylindrical tip of the pin and understand why it is technically meaningful.

Thus the board has reached the conclusion that document O5-bis discloses features 20 and 20'.

4.2.4 Conclusion

Claim 1 is novel over document O5-bis because this document does not clearly and unambiguously disclose feature 16.

4.3 Inventive step

4.3.1 Admissibility of the objection based on document O5-bis

The board has admitted the line of attack based on document O5-bis, which is state of the art within the meaning of Article 54(2) EPC 1973 and which had been cited as being novelty-destructive. The appellant's novelty objection was almost successful: only one feature was found not to be directly and unambiguously disclosed. In such a situation it appears to be both legitimate and reasonable to examine whether the sole distinguishing feature involves an inventive step.

4.3.2 Starting point

The board considers document O5-bis to be a promising starting point. The document belongs to the same technical field and discloses all features of claim 1 but one.

Claim 1 as it stands encompasses drill pipes. Therefore, the board cannot endorse the respondent's argument that document O5-bis is unsuitable as starting point.

As the board reaches the conclusion that the subject-matter of claim 1 is not inventive over the disclosure of document O5-bis, it is not necessary to consider other possible starting points.

4.3.3 Differences

As has been shown above (see point 4.24.2 ), Claim 1 differs from the disclosure of document O5-bis by feature 16, i.e. in that the nose portion of the pin does not contact the portion of the box facing it. Document 05-bis has no clear teaching on whether there is contact or not.

4.3.4 Obviousness

The board has reached the conclusion that the above mentioned distinguishing feature cannot establish an inventive step, for the following reason:

When trying to implement the teaching of document O5-bis, the skilled person would see the need to ensure good sealing contact between the box and the pin, i.e. between the contact surfaces 13 and 14 on the one hand and the conical surfaces 15 and 16 on the other hand. In order to reach this goal, the skilled person would see the need to avoid any further contact between box and pin that could lead to the above mentioned sealing contact being compromised or disturbed. The most straightforward way of answering that need would be to provide a (possibly small) gap between the nose portion of the pin and the portion of the box facing it. When proceeding along that way, the skilled person would reach a solution that is encompassed by claim 1.

None of the arguments presented by the respondent invalidates the above reasoning. There may be reasons why the skilled person would wish to have further support contact, but he would consider the necessity to preserve good sealing to be of overriding importance. It may also be true that the skilled person would want to have the nose portion as thick as possible in order to increase its resistance against deformation, but this only means that he would make the gap as thin as possible. It should be noted that the fact that a gap is provided does not necessarily lead to a reduced stiffness of the pin, because the gap can also be obtained by a modification of the box.

4.3.5 Conclusion

The subject-matter of claim 1 does not involve an inventive step within the meaning of Article 56 EPC 1973.

The main request has to be dismissed.

5. Auxiliary request 1

Claim 1 of auxiliary request 1 differs from claim 1 of the main request in that "any shoulder surface of the pin [is] formed at an end of the pin".

5.1 Claim interpretation

5.1.1 "any shoulder surface"

According to the Oxford English Dictionary, "any" is used to refer to an unspecified number or quantity of a thing or things, no matter how much or how many. Thus the feature is understood to mean that, regardless of the number of shoulder surfaces of the pin (one or more), all of them are formed at an end of the pin.

5.1.2 "end of the pin"

The expression "end of the pin" has to be distinguished from the expression "end face of the pin" used in claim 1 of the main request. The board is of the opinion that the skilled person would understand that, in the context of a pin for threaded joints for steel pipes, the expression designates the axial end of the pin which is in abutment with the box when pin and box are interengaged. See, for instance, paragraph [0007] of the opposed patent: "... an unthreaded portion 12 called a lip ... located at the end of the pin 1 ..." in connection with Figure 1.

FORMULA/TABLE/GRAPHIC

5.2 Basis for the amendment

The feature as such is not explicitly disclosed in the original application.

Original claim 1 requires the pin of the claimed joint to have "a shoulder surface" (cf. feature 6). It then requires that "the shoulder surface of the pin is provided at the end face of the pin" (cf. feature 13). The wording of the claim does not exclude that the pin has more than one shoulder surface, but it does not suggest it either (as it would have, had the expression "at least one shoulder surface" been used). The amendment introducing the notion of "any shoulder surface" modifies the situation in that it suggests the existence of more than one shoulder surface.

Page 10, lines 2-10 of the original application is different in that it refers to "at least one shoulder surface 14". This part of the description corresponds to Figures 1 and 5. It unambiguously teaches that "the shoulder surface 14 ... [is] formed on the end of a pipe". However, the embodiments shown in Figures 1 and 5 clearly have pins in which there is only one shoulder surface at the end of the pin. The other end of the pin is not shown. If the pin depicted has several shoulder surfaces, the other shoulder surfaces must be provided elsewhere than at the end of the pin. Thus this part of the description does not provide sufficient support for the amendment under consideration either.

Page 16, lines 7-19 of the original application explains that "in the preceding description" an embodiment with a shoulder surface "on the lip at the end of a pin" was described. The description then refers to Figures 8 and 9 which exemplify that embodiments are possible in which a second series of shoulder surfaces 33 are provided.

FORMULA/TABLE/GRAPHIC

However, the shoulder surface 33 is not at the end of the pin 1 within the meaning of the opposed patent (see point 5.15.1 ). In other words, in the only embodiment with two shoulder surfaces the second series of shoulder surfaces 33 is not provided at the end of the pin.

Claim 20 of the original application requires the joint to be provided with "a second series of shoulder surfaces at an end portion of the box". This disclosure, however, does not allow to draw any conclusions on the number and location of the shoulder surfaces of the pin.

Considering all the above, the board has reached the conclusion that the feature according to which any shoulder surface of the pin is formed at an end of the pin is not directly and unambiguously disclosed in the original application. Consequently, the amendment does not comply with the requirements of Article 123(2) EPC.

As a consequence, auxiliary request 1 has to be dismissed.

6. Auxiliary request 2

Claim 1 of auxiliary request 2 differs from claim 1 of the main request in that the pin has only one shoulder surface.

Page 10, lines 2-10, of the original application states that in the threaded joints depicted in Figures 1 and 5 "[t]he pin member 1 has ... at least one shoulder surface 14 formed on the end portion of a pipe" (emphasis by the board). The board is satisfied that this also discloses the case where there is precisely one shoulder surface. However, this feature is only disclosed for this particular embodiment (Figures 1 and 5).

The respondent has not persuaded the board that this feature was disclosed in combination with all the other features of claim 1. The embodiments of Figures 6-10 are distinct embodiments; the application cannot be said to directly and unambiguously disclose any combination of features taken from different embodiments.

The respondent has referred to "[a]ll of the embodiments except for the Figure 8 embodiment" as having only one shoulder surface, but, as a matter of fact, Figures 5 to 7 show only part of the pin. Figure 9 shows an embodiment having a second shoulder surface. Figure 10 is a very particular embodiment in which the pin end has been subjected to swaging to reduce both the pipe diameter at the end and increase the wall thickness of the pin lip. It is no suitable basis for the general teaching that a pin according to the invention may have only one shoulder surface. Therefore, the Figures appear not to be a sufficient basis for the amendment.

Original claim 1 only requires the pin to have "a shoulder surface"; this abstract language does not allow to draw any conclusion on the number of shoulder surfaces.

Original claim 20 deals with shoulder surfaces of the box and is silent on the pin. As can be seen from Figure 10, for instance, the number of shoulder surfaces of the pin does not necessarily correspond to the number of shoulder surfaces of the box.

Arguably the original application discloses the feature according to which the pin has only one shoulder surface at an end of the pin, but there is no direct and unambiguous disclosure that the pin has only one shoulder surface, regardless of its location.

Considering all the above, the board has reached the conclusion that the feature according to which the pin has only one shoulder surface is not directly and unambiguously disclosed in the original application. Consequently, the amendment does not comply with the requirements of Article 123(2) EPC.

As a consequence, auxiliary request 2 has to be dismissed.

7. Auxiliary request 3

Claim 1 of auxiliary request 3 differs from claim 1 of the main request in that:

- the threaded joint comprises means for allowing a portion of the male thread located adjacent to the sealing surface to escape from engaging with a female thread (feature 22);

- those means consist in a circumferential groove provided on the inner surface of the box between the female thread and the sealing surface of the box (feature 23);

- the axial length of the circumferential groove measured between the female thread and the sealing surface of the box is between 1.5 to 3.5 pitches of thread (feature 24).

7.1 Admissibility

Claim 1 of auxiliary request 3 is identical with claim 1 of auxiliary request 11, which had been filed before the oral proceedings, except that one feature has been deleted. Thus the appellant could not be surprised by the additional features, all the more as they were also part of claim 1 of several auxiliary requests filed before the oral proceedings. Having considered all these aspects, the board has decided to admit auxiliary request 3 into the proceedings.

7.2 Claim interpretation

Feature 22 requires means for allowing a portion of the male thread located adjacent to the sealing surface to escape from engaging with a female thread. According to the established practice of the EPO, "means for" is understood to mean "means suitable for". Moreover, the board interprets feature 22 such that it inter alia requires the male thread to have a portion located adjacent to the sealing surface. The Oxford English dictionary defines "adjacent" as "next to or very near something else; neighbouring; bordering, contiguous; adjoining". This understanding also corresponds to what is depicted in Figures 1 and 5.

7.3 Inventive step

7.3.1 Closest prior art

Document O5-bis is considered to be the the closest prior art.

7.3.2 Differences

The box 1 of Figure 1A of document O5-bis comprises a circumferential groove 7 provided on the inner surface of the box between the female thread 5 and the sealing surface 13,14 of the box. Thus feature 23 is disclosed in document O5-bis.

The male thread 11 of pin 2 does not have any portion that is adjacent to the portions of surfaces 15 and 16 that act as sealing surface (see point 7.27.2 ).

When the box 1 and the pin 2 are assembled to form the joint, the male thread 11 cannot extend into the groove by more than one thread pitch. Further advancement into the groove is made impossible by the abutment of the shoulder surfaces 3 and 9. Thus no significant portion of the male thread 11 can be said to escape from engaging with the female thread within the meaning of feature 22. Also, the length of the groove 7 clearly exceeds 3.5 pitches of thread.

7.3.3 Technical effect

The main technical effect of the distinguishing features is to increase the stiffness of the pin without compromising the sealing contact.

The corresponding objective technical problem is to obtain this effect.

7.3.4 Obviousness

What remains to be examined is whether the skilled person starting from document O5-bis and wishing to increase the stiffness of the pin without compromising the sealing contact would, based on the state of the art and his common general knowledge, find a solution encompassed by claim 1.

The appellant has based his argumentation on the assertion that for the skilled person providing the distinguishing features was a mere matter of design. The board does not find this argumentation persuasive. In particular, it is not apparent to the board why the skilled person would choose the axial length of the circumferential groove to be between 1.5 to 3.5 pitches of thread and the male thread to have a portion located adjacent to the sealing surface, where the risk of interference with the sealing contact is greatest. The mere assertion of routine choice cannot replace a conclusive demonstration of why the skilled person would be led to the particular choice of the invention.

Thus the board has reached the conclusion that the appellant has not established that the subject-matter of claim 1 is obvious to a person skilled in the art and that, as a consequence, the invention shall be considered as involving an inventive step within the meaning of Article 56 EPC 1973.