Schlumberger Logelco Incorporated v Coflexip SA

Schlumberger Logelco (appellant) installed apparatus for transferring oil from the seabed to the sea surface at a Soekor Field Development Project near Mossel Bay. Coflexip SA (respondent) held Patent 89/1418, granted with priority date 24 February 1988, relating to apparatus using at least one hose (flexible-pipe risers) for fluid transfer between seabed and sea surface. The Commissioner of Patents (Southwood J) found that the appellant's apparatus infringed claims 1, 8 and 9 of the patent, granted an interdict, and dismissed the appellant's counterclaim for revocation of the patent. The patent concerned a "pliant wave configuration" which was a hybrid between known "Lazy S" and "Steep S" configurations, using holding means connected to a deadman on the seabed to hold taut part of the hose and impart a predetermined curvature directed toward the wellhead.

• Whether the appellant's Soekor apparatus infringed the respondent's patent, particularly integers (v) and (vii) of claim 1
• Whether the patent was invalid for lack of novelty in light of prior art (Rauma-Repola drawing and GB Patent 2 163 403 A)
• Whether the patent lacked an inventive step (was obvious) to a person skilled in the art
• Whether the patent claims lacked clarity as required by section 61(1)(f) of the Patents Act 57 of 1978
• The admissibility and role of expert evidence in determining obviousness

Appeal dismissed with costs, including costs of two counsel. The findings of the Commissioner of Patents were upheld: the patent was valid and had been infringed by the appellant.

The binding legal principles are: (1) In patent infringement cases, a distinction must be drawn between what determines the extent of a feature and what imparts that feature - holding means can impart a curvature even though other factors determine its extent. (2) For anticipation/lack of novelty, prior art must contain all essential integers of the claimed invention; a difference in even a single essential integer defeats the anticipation claim. (3) Expert evidence on obviousness: expert witnesses may give primary technical evidence about the nature of the inventive step, the state of the art, and how the step differs from that art, but their opinions as to whether the invention is or is not obvious are not determinative - that is a question for the court. (4) Secondary evidence including commercial success and failure of well-resourced competitors to find the same solution remains relevant in assessing inventiveness. (5) Patent claims will not be found unclear merely because they contemplate alternatives or make multiple related references to the same subject matter, provided the skilled reader can understand what is required.

The Court made several non-binding observations: (1) The passage in Mölnlycke AB v Procter & Gamble regarding expert evidence on obviousness (quoted with approval in Ensign-Bickford) was not intended to change the law on admissibility of expert evidence, but rather to clarify that technical evidence by experts constitutes the primary evidence, not their opinions on the ultimate issue of obviousness. (2) The Court noted that expert witnesses may sometimes find it difficult to avoid expressing conclusions about obviousness, but clarified this does no harm so long as it is understood such conclusions are immaterial. (3) In interpreting technical drawings as prior art, courts may have regard to expert evidence about what is depicted, similar to the approach for photographs set out in C van der Lely NV v Bamfords, though this is subject to the qualification that some drawings (like some photographs) may require no expertise to interpret. (4) The Court observed that the invention created an "elegant" solution that was being extensively used commercially while the Bechtel alternative configuration was not used at all, suggesting practical superiority beyond mere inventiveness.

This case is significant in South African patent law for several reasons: (1) It clarifies the interpretation of patent claims, particularly the distinction between what "determines" a feature (extent of curvature) versus what "imparts" that feature. (2) It addresses the test for novelty under section 25(5) and (6) of the Patents Act 57 of 1978, applying the principle from Netlon Ltd v Pacnet that anticipation requires the prior publication to contain all essential integers of the claim. (3) Most importantly, it clarifies the role of expert evidence in assessing obviousness under section 25(10). The Court distinguished between admissible technical evidence (nature of the step, state of the art, how the step differs) and inadmissible opinion evidence (expert's conclusion on whether obvious), refining the approach in Ensign-Bickford v AECI Explosives. (4) It confirms that secondary evidence (commercial success, failure of others to find the solution) remains relevant in assessing inventiveness. (5) It demonstrates the application of clarity requirements under section 61(1)(f).