Patents - The Appeal in Geofabrics v Fiberweb Geosynthetics


Jane Lambert

Court of Appeal (Lord Justices Lewison and Arnold and Sir Nicholas Patten) Geofabrics Ltd v Fiberweb Geosynthetics Ltd (Rev 1) [2021] EWCA Civ 854 (11 June 2021)

In Geofabrics Ltd v Fiberweb Geosynthetics Ltd [2020] EWHC 444 (Pat) (5 March 2020) which I discussed in Patents - Geofabrics Ltd v Fiberweb Geosynthetics Ltd. on 12 March 2020, Mr David Stone, sitting as a deputy judge of the High Court, held that Geofabrics Ltd.'s  European patent (UK) 2 430 238 for a "trackbed liner and related methods" was valid and infringed by the defendant company, Fiberwed Geosynthetics Ltd.  Fiberweb applied to the Court of Appeal for permission to appeal against Mr Stone's judgment. Lord Justice Floyd allowed Fiberweb to appeal on the grounds that (1) the deputy judge had erred in his construction of claim 1 of the Patent, and as a result, had wrongly found that  Fiberweb's Hydrotex 2.0 product ("Hydrotex") fell within the scope of the claim and (2) that the judge had been wrong to conclude that claim 1 did not lack novelty over International Patent Application No. WO 95/04190 ("Hoare"), Lord Justice Floyd refused permission to appeal against Mr Stone's finding that the patent in suit was not obvious over Hoare.

The Proceedings

The appeal came on before Lord Justices Lewison and Atnold and Sir Nicholas Patten on 27 May 2021. Their lordships handed down judgment on 11 June 2021,  Lord Justice Arnold gave the lead judgment. All three members of the Court of Appeal dismissed the appeal.

The Invention

The problem that the invention addressed had beern summarized by Mr Stone in the following paragraphs of his judgment which Lord Justice Arbold quited in full in para [2] of his own:

"5. When constructing a railway track, a foundation, called a trackbed, is built, on to which the railway track is laid. Typically, the trackbed comprises a 300mm to 500mm deep layer of ballast, made of graded, crushed rock aggregate. The ballast is laid onto the soil (called the subgrade). By way of example, Figure 1 of the Patent is shown here, with the rails (16 and 18) placed on the ballast (20) which is in turn placed on the subgrade (22):

6. The nature of the subgrade will depend on the local geography. Approximately 10% of the United Kingdom's rail network is laid on a subgrade with a high clay and silt content, such as London Clay or Oxford Clay. Clay subgrades can vary in moisture content – when very dry, they can take on the strength of a house brick, but when very wet, they can become a slurry. The pores of the clay can contain water, which can remain in the subgrade even for decades. When it rains, water passes down through the ballast until it reaches the subgrade, and this can, over time, cause a liquid slurry to form on the upper surface of the subgrade.
7. When a train passes over a track which has been laid over clay subgrade, a short-lived heavy load is transmitted downwards via the ballast to the subgrade. A train has many wheels: therefore a rapidly repeating heavy load is applied. This will tend to cause the pore water to be squeezed out of the clay. This can lead to pumping erosion: as the pore water is forced out of the subgrade, it carries with it fine particles of clay and silt. Over time, the removal of the clay and silt particles causes erosion to the trackbed, and settling of the track. By way of example, Figure 5 from the Patent is shown here and shows a vertical cross-section through a typical railway track with the cross-section running lengthways down the track. The tracks (116) are placed on sleepers (48), which are placed on ballast (120), which is placed on the subgrade (122). As the train (46) passes over (A), pumping erosion (52) occurs:

8. The end result of pumping erosion is shown in this photograph taken from the evidence of the Defendant's expert in this case, Professor Terry Ingold. The slurry has migrated up through the ballast, such that it is 'daylighting'.

9. The problem of pumping erosion has long been well known. Traditionally, it was addressed using a 100mm to 150mm layer of sand, placed between the subgrade and the ballast. The sand acted as a filter, slowing the passage of water, and trapping the fine clay and silt particles. But sand had known disadvantages, primarily because it was expensive and inconvenient to lay. Finding a replacement was therefore desirable. Thus, instead of sand, various synthetic trackbed liners have been tried. The Patent, alleged infringement (Hydrotex) and prior art in this case all concern such synthetic liners."

Lord Justice Arnold said at para [3] that the patent was directed to a synthetic trackbed liner made of a "filtration layer" which restricts the passage of solids material through the liner sandwiched between two "support layers". That was put forward as a solution to the problem of pumping erosion described above. I outlinbed the invention in the paragraph headed "Patent in Suit" in my previous post.  Lord Justice Arnold gave more details between para [4] and para [13] of his judgment.  He also broke claim 1 into integers at para [14], identified tghe skilled addressee at para [15] and his common general knowledge at [16].

Construction of Claim 1

I discussed Mr Stone's construction of claim 1 under the heading "Construing the Patent" in my previous post.  Lord Justice Arnold discussed it further between paras [17] and [22].  Fiberweb argued that the deputy judge had wrongly construed the claim, and that "normally impermeable" means "impermeable under a water pressure equivalent to that of the load of track, sleepers and ballast" which is said in the specification at [0056] to be typically about 2.9kN/m2. Thus Fiberweb contended that the criterion for impermeable is impermeability under a water pressure equivalent to about 2.9kN/m2 though it was common ground that nothing turned on the precise figure.

Lord Justice Arnold rejected that contention for the following reasons:

"[22] First, that is not how "normally impermeable" is defined in the specification and in the claim. The question of whether any particular material satisfies the definition in the specification and the claim is a separate question, and is a question of fact.
[23] Secondly, [0056] is part of the discussion of the specific embodiments. It is rarely appropriate to read a limitation into a claim by reference to stray comments in the description of a specific embodiment, but it is clearly illegitimate when (i) the specification and the claim define the meaning of the expression in question and (ii) that definition does not include the criterion contended for by Fiberweb.
[24] Thirdly, the argument is based on a confusion between the static load on the filtration layer due to the presence of the track, sleepers and ballast on the one hand and the dynamic load exerted during the passage of a train on the other. As the specification makes clear at [0056], the figure of about 2.9kN/m2 is typical of the "static loading … due to the ballast 20 and track 14". The same paragraph goes on to refer to the "peak dynamic stress during passage of the train" in contradistinction to the "static loading". There is no dispute that [0023] and [0054] make it clear that it is the dynamic load exerted during the passage of the train which matters for the purposes of the invention, and this is reflected in integer 1.6 of claim 1. Although, as counsel for Geofabrics accepted, [0023] and [0054] are not as pellucid as they might be, they also make it reasonably clear that the reason why it is the dynamic load exerted during the passage of the train that matters is because of its effect on the pressure of the water which is present (i.e. the hydrostatic pressure).
[25] Fourthly, as the skilled reader would appreciate, this is in accordance with basic physics. As the experts agreed, the static load due to the presence of the track, sleepers and ballast is a load applied during the construction of the track. This force generates an equal and opposite reaction (Newton's Third Law) exerted by the subgrade. Thereafter the system is in equilibrium. Although the result is compression of the liner (which is part of the reason why it needs a degree of robustness as explained at [0019]), this would have no bearing on the hydrostatic pressure of any water present."

Having rejected the appellant's definition of "normally impermeable" in the context claim 1, it followed that the defendant's Hydrotex product fell within claim 1.

Lack of Novelty

Lord Justice Arnold said at [42}:

"In order to establish that claim 1 lacks novelty over Hoare, Fiberweb must show it discloses subject matter which, if performed, would necessarily result in infringement of the Patent: Synthon BV v SmithKline Beecham plc [2006] RPC 10 at [22]."

In that case, Lord Hoffmann had approved the following decision of the Board of Appeal of the European Patent Office in T-396/89 UNION CARBIDE/High tear strength polymers [1992] EPOR 312 at [4.4]:

"It may be easy, given a knowledge of a later invention, to select from the general teachings of a prior art document certain conditions, and apply them to an example in that document, so as to produce an end result having all the features of the later claim. However, success in so doing does not prove that the result was inevitable. All that it demonstrates is that, given knowledge of the later invention, the earlier teaching is capable of being adapted to give the same result. Such an adaptation cannot be used to attack the novelty of a later patent."

Lord Hoffmann had said at [25]:

"As I have indicated by reference to the quotation from UNION CARBIDE, it is this requirement that performance of an invention disclosed in the prior art must necessarily infringe the patent which distinguishes novelty from obviousness. If performance of an invention disclosed by the prior art would not infringe the patent but the prior art would make it obvious to a skilled person how he might make adaptations which resulted in an infringing invention, then the patent may be invalid for lack of an inventive step but not for lack of novelty."

Lord Justice Arnold also mentioned Lord Justice Jacob's observation in Dr Reddy's Laboratories (UK) Ltd v ELI Lilly and Co Ltd [2009] EWCA Civ 1362, [2010] RPC 9 at [23]-[33] that it is necessary in order for an earlier disclosure to anticipate a later claim that the earlier disclosure contains an "individualised description" of something falling within the later claim.

I explained why Mr Stone had rejected Fiberweb's case of lack of novelty in my previous post. Lord Justice Arnold quoted the same passage of the deputy judge's judgment.  Lord Justice Arnold accepted Fiberweb's submission that sub-paragraph (a) was fallacious in that it merely amounted to saying that Hoare had not disclosed the inventive concept of the patent, when that was not required for anticipation (although it might be relevant to obviousness). However, he did not accept the appellant's second submission that reason (b) involved misreading the disclosure of Hoare at [0017], with its cross-reference to Gore. There was a good reason for the cross-reference in that it directed the reader to specialist materials that could be used to make a product that anticipated the patented invention.

Further Information

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