T 0905/17 - No need for a hint in the CPA

Key points

• This opposition appeal deals with inventive step.
• “The opposition division dismissed this line of argument [of the opponent] by pointing out that there was no "hint in [the closest prior art] document D4 to suppress the liner (3) and then to search for appropriate material in the prior [sic] for the pressure armours (5,6) then subjected to corrosion"”
• “The board does not find this reasoning [of the OD] persuasive because the skilled person starting from one element of the state of the art [i.e. starting from the closest prior art] and faced with the need to solve a given problem [i.e. the objective technical problem] does not necessarily need a "hint" associated with that element. Otherwise, it would never be possible to establish a lack of inventive step based on the object of a prior public use, which usually does not come with any hints. In the absence of a hint, the skilled person might still take the steps leading to the claimed subject-matter on the basis of their common general knowledge or documents belonging to the state of the art that explicitly teach a solution to the problem to be solved.”
• However, the Board still concludes that the opponent “has shown that the skilled person starting from the teaching of document D4 and wishing to simplify the design of the pipe disclosed in that document could have reached the subject-matter of claim 1. However, they have not established in a persuasive manner that the skilled person would have done so. Their argumentation appears to be based on hindsight.”

EPO T 0905/17 -  link

3.2.3 Obviousness

The appellant [opponent] argued that the skilled person contemplating the pipe of Figure 2 of document D4 would have noted that its structure was repetitive: there is a first structure formed by layers 1 and 3 and a second structure formed by layers 5, 6 and 9.

FORMULA/TABLE/GRAPHIC

The argument goes on to say that the skilled person trying to simplify the pipe design would have eliminated this repetition of structures by removing both the carcass 1 and the inner liner 3. Sheath 9 would then replace inner liner 3 and layers 5 and 6 would play the role of the carcass 1. As they are in direct contact with the fluid to be transported, said layers would be unable to bear the radial force exerted by the internal pressure of the fluid. However, document D5 provides a solution that would have led the skilled person in an obvious way to a pipe according to claim 1.

The opposition division dismissed this line of argument by pointing out that there was no "hint in document D4 to suppress the liner (3) and then to search for appropriate material in the prior [sic] for the pressure armours (5,6) then subjected to corrosion" (see page 5, first paragraph, of the decision under appeal).

The board does not find this reasoning persuasive because the skilled person starting from one element of the state of the art and faced with the need to solve a given problem does not necessarily need a "hint" associated with that element. Otherwise, it would never be possible to establish a lack of inventive step based on the object of a prior public use, which usually does not come with any hints. In the absence of a hint, the skilled person might still take the steps leading to the claimed subject-matter on the basis of their common general knowledge or documents belonging to the state of the art that explicitly teach a solution to the problem to be solved.

Considering the fact that document D4 teaches that the pressure armour would "always" be located between the inner and outer liner of the pipe (see document D4', page 2, lines 19 and 20), it is at least doubtful that the skilled person contemplating a simplification of the pipe of document D4 would have eliminated one of those liners.

The counter argument based on the penultimate paragraph of the description of document D4:

"... the K-profiles can also be used advantageously as internal pressure armour in the inner liner, in cases where it is desired to armour the inner liner against substantial external compressive forces" (see document D4', page 10, lines 4 to 6)

is not persuasive because this passage would naturally be understood to mean that the K-profiles may constitute an additional (as opposed to: alternative) internal pressure armour.

Incidentally, the board fails to see why the layers 5 and 6 should not be considered as armouring layers in an embodiment based on this suggestion. This interpretation ignores the very wording of the passage ("used ... as internal pressure armour", "armour the inner liner").

There is also merit in the argument that the skilled person would not have envisaged replacing an inner liner (which serves to transport hot hydrocarbon material under pressure) with an intermediate sheath (which serves to prevent fluid migration between armour layers) or an outer sheath (which serves to avoid contact of the armour with sea water). It is true that the skilled person is capable of adapting the materials used to the specific conditions of use, but they would not modify an existing structure in a very substantial way without any clear incentive to do so.

In summary, the appellant has shown that the skilled person starting from the teaching of document D4 and wishing to simplify the design of the pipe disclosed in that document could have reached the subject-matter of claim 1. However, they have not established in a persuasive manner that the skilled person would have done so. Their argumentation appears to be based on hindsight.

As a consequence, this line of attack fails.