Lord Justices Floyd and Arnold disagree on the inventiveness of expandable hoses [2020] EWCA Civ 871

Some of the best inventions are the most simple. When judging the inventiveness of a simple invention, it is difficult not to be prejudiced by hindsight. An invention may seem obvious once an inventor has pointed the way, making it hard to recognise the inventive leap that was required. The case of Emson v Hozelock ([2020] EWCA Civ 871) considered whether a relatively technically simple invention was non-obvious in view of an obscure prior art document. The invention was found obvious using the UK legal test for inventive step, in a result that the judges themselves noted might seem unfair. The difficultly inherent in the case was reflected by the disagreement between the two patent specialist judges who heard the case, Lord Justices Arnold and Floyd. 

The EP (UK) patent (EP2657585) related to a collapsible garden hose, the Xhose. The Xhose was invented by a sole inventor, Mr Berardi, in his garden. The Xhose, licensed to Emson, has enjoyed considerable commercial success but has been facing competition in the UK from a rival product, Hozelock's SuperHose. The Court of Appeal considered Emson's appeal from a High Court decision finding the Xhose patent obvious in view of a prior art patent document, McDonald (US 2003/0000530)

McDonald related to a self-elongating oxygen hose for a mask. McDonald and the Xhose therefore related to different fields of hoses. The difference between McDonald and the invention was that McDonald did not disclose a garden water hose. The state of the art used to assess both novelty and inventive step in the UK includes any document published anywhere in the world before the priority date of the patent. Therefore, despite being a rather niche document from the aeronautical field, McDonald was still state of the art for the Xhose. 

UK versus EPO inventiveness

In the UK, the inventiveness of a claimed invention is assessed using the Windsurfer/Pozzoli test ([2007] EWCA Civ 588):

(1)(a) Identify the notional “person skilled in the art”

(1)(b) Identify the relevant common general knowledge of that person;

(2) Identify the inventive concept of the claim in question or if that cannot readily be done, construe it;

(3) Identify what, if any, differences exist between the matter cited as forming part of the “state of the art” and the inventive concept of the claim or the claim as construed;

(4) Viewed without any knowledge of the alleged invention as claimed, do those differences constitute steps which would have been obvious to the person skilled in the art or do they require any degree of invention?

As can be seen, the Windsurfer/Pozzoli test concludes by asking the very question it is supposed to answer, i.e. is the invention obvious in view of the prior art? The purpose of the preliminary steps in Windsurfer/Pozzoli is to "put one in the proper frame of mind to answer the question of the final step" (see Manual of Patent Practice, 3.15). The Windsurfer/Pozzoli test contrasts with the problem-solution approach to inventive step taken by the EPO. The problem-solution approach is more rigid and contains 3 stages: 

(i) determining the "closest prior art", 

(ii) establishing the "objective technical problem" to be solved, and 

(iii) considering whether or not the claimed invention, starting from the closest prior art and the objective technical problem, would have been obvious to the skilled person. 

UK and EPO patent law are supposed to be aligned. The often repeated view of UK judges is that the Windsurfer/Pozzoli test and problem-solution approach should yield the same answers on a particular question of inventive step. However, the case of Xhose highlighted the differences between the tests and particularly, in this Kat's view, the potential disadvantages of the Windsurfer/Pozzoli test. 

Was it obvious?

On appeal, Emson argued that the High Court's conclusion that the Xhose was obvious was based on an analysis tainted by hind-sight. Emson further argued that the considerable commercial success of the Xhose was evidence of its non-obviousness. Given that McDonald had been around for a long time, if the invention had been so obvious, surely someone would have designed such a hose before Mr Berardi? 

However, both Arnold LJ and Floyd LJ were in agreement that the commercial success of Mr Berardi's invention could not be relied on to demonstrate inventiveness. As Floyd LJ put it, whilst "viewed against the common general knowledge of garden hoses, the invention was one of breathtaking ingenuity", the issue of obviousness had to be assessed with respect to the state of the art, i.e. McDonald, not the common garden hose. 

Arnold LJ agreed with the High Court that McDonald related generally to the field of self-elongating hoses that could be used for multiple purposes, including garden hoses. Arnold LJ thus found that a skilled person would combine the disclosure of McDonald with their common general knowledge of garden hoses to arrive at the invention. Arnold LJ importantly noted the lack of anything in McDonald that would teach way from applying the disclosure to garden hoses. Arnold LJ therefore found that hindsight had not tainted the High Court's finding that the Xhose was obvious in view of McDonald. 

Dissent among the patent judges

Floyd LJ disagreed with Arnold LJ on the hindsight point. In particular, Floyd LJ argued that the first instance judge had made two fundamental errors when finding the Xhose obvious:

First, the judge had treated McDonald as a real, practical machine, as opposed to a mere paper proposal. There was however no evidence that the hose described McDonald had every been made, let alone commercialised. Floyd LJ concluded that the suggestion that McDonald would interest a garden hose skilled person should have been approached "with a high degree of scepticism" (para. 105). Furthermore, in Floyd LJ's view, the judge at first instance had ignored key expert evidence that a person skilled in garden hoses would not even fully understand how the hose of McDonald was supposed to work (para. 110). 

Second, Floyd LJ found that the expert evidence pointed to the fact that the problem solved by McDonald was not one that a garden hose skilled person would be interested in. McDonald purported to provide a space-saving hose. In Floyd LJ's view, part of the invention of Mr Berardi resided in him identifying that a light, non-kinking, space-saving garden hose was something people would want. In the view of Floyd LJ, the first instance judge had used hindsight in finding that a garden hose skilled person would find anything of interest in McDonald, especially since the basic garden hose design hadn't changed for decades. As Floyd LJ summarised: 
The idea that that the notional, unimaginative skilled person with an interest in this industry would seize on an untested proposal from a "very particular and very distant field" has the air of unreality when no ideas (even practical ones) appear to have been so transposed for so long. 
In contrast to Arnold LJ, Floyd thus found that there was nothing in McDonald to suggest the idea of an expandable garden hose and, for his part, would have allowed the appeal.

The deciding vote

Lord Justice Henderson was left with the deciding vote. Henderson LJ agreed with Arnold LJ that the Xhose was not inventive in view of McDonald. However, Henderson LJ commented that the result "may appear harsh, even unfair, to Mr Berardi. One feels intuitively that he should be able to reap the rewards of his brilliantly simple invention". None-the-less, Henderson LJ was unpersuaded by Floyd LJ's argument that less weight should be given to McDonald because the disclosure in McDonald had not been realised. For Henderson LJ, the key point was that the inventive concept underlying the Xhose was unambiguously disclosed by McDonald, and that a person skilled in technical hoses in general would apply McDonald to garden hoses. 

Problem-Solution versus Windsurfer/Pozzoli

Part of the problem the judges faced in this case was that the Windsurfer/Pozzoli test, in contrast to the EPO problem-solution approach, does not require a skilled person to identify "the closest prior art". The Windsurfer/Pozzoli test merely requires the inquisitor to identify the "state of the art". The state of the art can be any document published in any language anywhere in the world (MoPP, 3.36). As pointed out by Floyd LJ, the justification for this provision is that "once the possibility exists that a skilled person could obtain the document and consider what to do in light of it, a subsequent patent should not interfere with his freedom to take it forwards". By contrast, in the EPO's problem-solution approach, obviousness is assessed relative to the closest prior art. The closest prior art is the prior art that relates to the same field, the same technical problem and/or has the most features in common with the claimed invention, in that order of preference. 

Windsurfer/Pozzoli thus applied by Arnold LJ does not require the "state of the art" to represent the closest prior art. However, as soon as McDonald is assumed to be the starting point for an obviousness analysis, Emson faced an uphill battle. It is more difficult to argue that a garden hose skilled person who read McDonald would not apply its teachings to the field of garden hoses, than to argue that a garden hose skilled person would not be motivated to seek out McDonald to solve a problem associated with garden hoses. 

By contrast, at opposition, the EPO identified a garden hose as the closest prior art with respect to the Xhose. It was then possible for Emson to argue that a skilled person would not be motivated to consult McDonald, a specialist document from an entirely different field or aeronautics, in order to solve the problems associated with garden hoses. The opposition division (OD) thus found the European patent to be non-obvious (although the decision is currently under appeal). The approach of Floyd LJ, who found the Xhose inventive, mirrored the problem-solution approach by discounting McDonald as a suitable starting point for analysis of inventive step. 

All of the judges commented that, to a casual observer, the Xhose would seem obviously inventive or expressed sympathy for the sole inventor when finding his "simple and brilliant invention" obvious in view of a niche patent document of which the inventor had not been aware (see Arnold LJ at para. 76). Does this perhaps suggest that the problem-solution approach may be a better test for assessing obviousness than Windsurfer/Pozzoli? The problem-solution approach incorporates the idea that the best starting point for an inventive step analysis is a disclosure from the same field as the invention in preference to a document from a different field. The Problem-Solution approach thus gives more weight to whether a skilled person would be motivated to seek out other documents in order to solve a problem. Interestingly, the USPTO approach is again different. The USPTO generally gives very little credence to the argument that a skilled person would not be motivated to combine prior art documents from very disparate fields.

Regardless of your view with respect to the merits or otherwise of Windsurfer/Pozzoli, this case undoubtedly provides some interesting commentary on how to apply the test. 
Lord Justices Floyd and Arnold disagree on the inventiveness of expandable hoses [2020] EWCA Civ 871 Lord Justices Floyd and Arnold disagree on the inventiveness of expandable hoses [2020] EWCA Civ 871 Reviewed by Rose Hughes on Friday, July 24, 2020 Rating: 5


  1. May I draw your attention to the publication of the case in Kluwer Patent Blog and the comments to be found there.


    That a garden hose is the proper closest prior art appears not suffering any discussion.

    The only question left is whether the skilled person would take into consideration Mac Donald which deals with a breathing apparatus.

    In my humble opinion it does not matter for the pipe whether it forwards water or air as both are fluids. In the cooperative classification the EPO has also classified Mac Donald in F 16L 11, which deals with hoses without any limitation to the fluid transported by the hose.

    The OD sides with Floyd LJ, but I would slide with Arnold LJ.

    Let's see what the Board of Appeal will make out of it.

  2. Thanks to Rose Hughes for making a tantalizing contrast of the approaches.

    In Floyd LJ's analysis, he was bound by law to start with McDonald, which he then heavily discounted (and thereby creating a bigger gap between McDonald and the invention in question) for the reason that in his views McDonald was a "mere paper proposal".

    I would say that this case points to a flaw under the problem / solution approach, in that the choice of the CPA may not be straightforward and can make a material difference (like in relation to the present invention).

    For reference, the EPO Guideline states:
    In selecting the closest prior art, the first consideration is that it must be directed to a similar purpose or effect as the invention or at least belong to the same or a closely related technical field as the claimed invention.

    These guidelines aren't the clearest and they do not have express statutory basis. Instead of arguing what McDonald has disclosed to the skilled addressee, the real fight should be over whether McDonald may be the CPA.

  3. In this case the skilled person was taken as a hose designer, with knowledge of both garden hoses and other hoses (based on evidence that in the field of hose design there was no separate skilled person who would only look at garden hose design). Once it was accepted that the skilled person was in a technical field of hoses (rather than specific to garden hoses) the starting point appears to be more fair? I wonder if the possible unfairness of the decision is simply due to the breadth of prior art available - sometimes you just have to be unlucky that a similar idea was identified but not successfully commercialised earlier?

  4. If the claim is directed to a water hose, the closest prior art can only be a water hose. Starting with an aerospace hose would be blatant hindsight.

    If the claim is not limited to a water hose, then any hose, can be taken as closest prior art.

    It is worth noting that the IPC, cf. F16L 11/.., only relates to hoses in general irrespective of the fluid transiting trough the hose. Mac Donald was classified by the USPTO in A61B or A61M, as it dealt with a breathing tube. However within the EPO Mac Donald was also classified in F 16L 11/...

    In order not to inject cold air into the lungs of a patient during artificial ventilation, a flexible breathing tube contains a heating spiral wound around it. If in the prior art, a flexible pipe carrying water is equipped with a heating spiral so that the water is tepid or does not even freeze, I would consider that the water pipe is novelty destroying for the breathing tube and vice versa.

    T 176/84 relates to a pencil sharpener comprising a movable closing so that the shavings would not fall from the box. At the time the board considered that the skilled person would not have looked at the closure system of a money box which also hinders the money falling out of the box. It is possible to say that T 176/84 corr4sponds to the position of Floyd LJ.

    The discussion was centred on whether the skilled person building a pencil sharpener would be looking at a money box or not. The decision was heavily commented, some approving it, some not.

    In spite of this very old decision, I am of the opinion that the majority decision is fully justified.

    Even if the claims would have originally been limited to water hoses, the patentee would not have had a stronger stance.

    In that he envisaged himself other uses as just water hoses, shows that it is acceptable to also take into account hoses not only carrying water.

    Most of the hoses disclosed as background art in the introductory part of the original description and in the patent do not relate to water carrying hoses.

    It is a pity that during the supplementary European search Mac Donald was not found as it bears the same classification unit, F 16L 11/12 as the patent.


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