First published in EPLAW Patent Blog, August 2021.
In this judgment, HHJ Melissa Clarke, sitting as a Judge of the High Court considered validity and infringement arguments relating to two of Ward’s patents (a Parent and Divisional) for “freight container tilting apparatus”. The Parent patent was found to be valid and also infringed by equivalents. The Divisional was found to be infringed under a normal construction, but invalid for added matter over the Parent. The judgment deals issues of obviousness and insufficiency as well as an unusual claim for estoppel by acquiescence, all of which were ultimately dismissed.
A Ward Attachments Limited (“Ward”) is the proprietor of EP 2 021 268 B1 granted on 11 May 2011 (“Parent Patent”) and a divisional patent EP 2 128 053 B1 granted on 9 January 2013 (“Divisional”). Both patents have the priority date of 26 May 2006 and relate to “an apparatus or device for receiving freight containers directly from the bed of a truck or trailer or other delivery mechanism, and tilting them to near-vertical to facilitate the loading and unloading of bulk materials”.
Fabcon Engineering Limited (“Fabcon”) manufactures light and heavy engineering equipment including, since 2009, container tilting machines. Ward sent Fabcon a ‘cease and desist’ letter on 13 May 2011 alleging infringement of several claims of the Parent Patent. Fabcon replied on 20 May 2011 stating that it did not agree that its container tilting machines were within the scope of the Parent Patent. The May 2011 letter gave reasons for this view and offered that Ward could inspect the relevant machines. The letter concluded by noting that, if Ward had not heard from the Claimant within 14 days, it would consider the matter closed. Ward did not reply to this letter and this lack of response subsequently formed the basis of the estoppel by acquiescence case run by Fabcon.
Ward sent Fabcon a Letter of Claim on 11 March 2019 alleging infringement of the Parent Patent and the Divisional. In this letter Ward’s solicitors stated it had not responded to Fabcon’s May 2011 letter since “our client decided not to pursue the matter further, as it was focused on its own commercial activity”. Ward issued its Claim for patent infringement on 1 July 2019.
Before dealing with the substantive issues in the case, the judge made some interesting observations of the parties’ expert evidence. In particular, the judge noted that counsel for Ward described Fabcon’s written expert report as “seriously flawed” due to the extremely short instructions provided to the expert. Fabcon’s counsel countered that “although [the expert’s] report does not read like a real lawyers document, that makes it more authentic, not less and this should be a commendation not a criticism”. Further Fabcon’s counsel suggested Ward’s expert evidence was “showing rather too much instruction”.
The judge agreed that the report “did not clearly identify the skilled addressee”; “wrongly sought the inventive concept in the words of Claim 1 of the Parent Patent rather than by considering the specification of the Parent Patent as a whole”; and “made an assumption about a feature of the Defendant’s apparatus without checking it, which set a hare running”. However, overall the judge found both experts honest, well qualified and useful even if she preferred Fabcon’s expert’s oral testimony over his written evidence.
Patents, skilled person and Common General knowledge (“CGK”)
The invention of the patents is designed to solve the problems with loading and unloading shipping containers with loads that can be poured (e.g. particulate materials). These problems arise because the containers are difficult to load and unload without tipping them up, and tipping the containers using known methods (forklift trucks or cranes) was subject to other problems. The solution of the patents is a tilting apparatus with a pair of tilting arms that lock to the container for security during the tipping process. Claim 1 of the Parent is set out below:
“A freight container tilting apparatus for tilting a freight container between a horizontal position and a tilted position for loading or unloading the container, the apparatus comprising: a base section, first and second tilt arms, each of the tilt arms being pivotably connected to the base section, and each of the tilt arms being configured or configurable to extend along substantially the whole length of the container to be tilted, first and second ends of each of the first and second tilt arms corresponding to opposite ends of the container, a container lock at the first and second ends of each of the first and second tilt arms, each container lock being configured to engage an end of the tilt arm with a side wall of the container, and at least one tilt arm drive configured to pivot each tilt arm relative to the base section, wherein each tilt arm is directly pivotably connected to the base section at a pivot point between the container locks at the first and second ends of the tilt arm and offset from the centre of the tilt arm, and the position of the pivot point relative to the base is fixed while the container is being tilted; and the height of the pivot point above a support surface used to support the base section is greater than the distance between the pivot point and the end of the tilt arm nearest the pivot point”.
Claim 1 of the Divisional, noted the judge, has the “same five basic structural elements as Claim 1 of the Parent” but the key difference “that references to the tilt arms engaging with the side walls of the container have been replaced with references to the tilt arms engaging with the front and rear end walls of the container”. This difference was important in the context of the infringement and added matter issues considered by the Court.
As noted above, Fabcon’s expert did not specifically address the identity of the skilled person but, in considering the relevant common general knowledge, Fabcon’s expert did provide some descriptors which the judge considered. These were somewhat different to Ward’s evidence on the skilled person.
Taking account of both sides’ arguments, the judge decided that the skilled address was “either: (i) in the field of equipment used for handling bulk materials, who has some experience in the field of container handling or who would consult someone with that experience; or (ii) in the field of container handling, who either has some experience in the field of handling bulk materials or who would consult someone with that experience”.
Both possible addressees were determined to have the same common general knowledge.
The judge made a number of findings as to the common general knowledge, the most important of which related to understanding the terminology used in the field. In particular the skilled person would understand the longer dimension of containers as the ‘sides’ and the shorter dimension as the ‘ends’;
Whilst the ‘rear’ end of the container usually means the end with doors, and the ‘front’ is the closed end of the container opposite the doors. The Patents are in fact drafted with the reverse terminology (i.e., describing the container end with doors as the “front”) but would nevertheless be understood by the skilled addressee.
Inventive concept and infringement
Ward only asserted infringement of Claim 1 of the Parent by virtue of the doctrine of equivalents. Accordingly, the judge had to consider the answers to the three Actavis questions (from Actavis UK Ltd v Eli Lilly & Co  UKSC 48):
- Notwithstanding that it is not within the literal meaning of the relevant claim(s) of the patent, does the variant achieve substantially the same result in substantially the same way as the invention, i.e. the inventive concept revealed by the patent?
- Would it be obvious to the person skilled in the art, reading the patent at the priority date, but knowing that the variant achieves substantially the same result as the invention, that it does so in substantially the same way as the invention?
- Would such a reader of the patent have concluded that the patentee nonetheless intended that strict compliance with the literal meaning of the relevant claim(s) of the patent was an essential requirement of the invention?
In order to answer these questions the judge needed to determine the ‘invention’ or ‘inventive concept’ against which the variants could be assessed. Further to developments in case law after Actavis the judge noted guidance that the inventive concept related to “the problem underlying the invention and the patent’s inventive core” (Icescape v Ice-World ( EWCA Civ 2219) and that “one should examine what is the problem underlying the invention and how does the patent solve that problem” (Evalve Inc v Edwards Lifesciences Ltd  EWHC 514 (Pat)).
Having considered both parties’ cases (including an argument from the Defendant that the patent had no inventive concept since it was “a wholly new machine with a wholly new combination of features which amounted to the identification of a new market” and therefore not protectable under patent law). The judge concluded that the invention was: “a container tilting apparatus with at least two pivotably connected tilt arms which allows a container to be: (i) delivered directly to it by a trailer or like delivery mechanism; (ii) secured to the apparatus in the vertical plane; (iii) released from the delivery mechanism (which can then be removed) by using small amounts of rotation around a single offset pivot; and (iv) tilted from horizontal up to 90 degrees to enable gravity-driven loading or unloading; and this process can be reversed once the tilting operation is completed.”
Crucially, the judge held that the inventive concept was not limited to a certain method of gripping and carrying the container. This was important for the equivalents infringement analysis because Fabcon’s apparatus gripped the end walls of the container whereas Claim 1 of the Parent was to an apparatus that gripped the side walls. Fabcon argued that, further to the language of the first Actavis question, there was a substantial difference between the literal meaning of Claim 1 of the Parent and the way in which Fabcon’s apparatus worked: the Fabcon machine did not grip the side walls of the container. Fabcon argued this was substantially different to the Claim 1 of the Parent as it was a safer way in which to grip the container during the tipping operation. However, the judge did not consider that this difference was substantial since the inventive concept did not include gripping the container in a specific way and there was no dispute that Fabcon’s apparatus achieved the same result as the invention of the Parent.
Fabcon did not dispute that the answers to the second and third Actavis questions were ‘yes’ and ‘no’ respectively and accordingly the Fabcon apparatus was found to infringe Claim 1 of the Parent by equivalents. Furthermore, since Claim 1 of the Divisional did refer to the tilting apparatus engaging with the front and end walls of the container, Fabcon’s apparatus was found to infringe this patent by normal construction.
Added matter of divisional
In a mirror image to the infringement analysis, the question before the judge for the invalidity argument against the Divisional was whether the application for the Parent taught the feature of engagement of the tilt arms with the front and rear walls. Fabcon submitted that it did not and “this is a paradigm case illustrating why such added matter is not allowed, since the amendments seek to add to the patent an apparatus that the Claimant did not invent, but rather copied from the Defendant after the Defendant’s apparatus came on the market.” Ward argued that “front” and “rear” engagement was taught particularly in view of references to a “front lock” and “rear lock” in the Parent application. The judge disagreed, pointing to references in the specification making it clear that the front and rear locks were still engaging the side walls (i.e. the terms related to a location on the side walls) and to testimony from both parties’ experts that no engagement with the end walls was taught in the Parent application. In view of this, the Divisional was found to have added matter over the Parent application and was revoked.
Obviousness and insufficiency allegations against both patents
Fabcon pleaded that the patents were obvious over two pieces of prior art, being BE 1014698A6 and DE 87 04 299U1. Fabcon did not, however, make oral submissions relating to obviousness and barely addressed the point in their skeleton argument. The judge further noted that Fabcon’s expert conceded that the differences between the prior art and inventive concept of the patents “may be” inventive. Accordingly, the obviousness case was dismissed.
Fabcon’s insufficiency arguments also failed. Fabcon had alleged that the skilled person would not understand with sufficient certainty what “freight” or “lock” meant and/or that the specification did not disclose “how the locks on the tilt arms are configured to engage the tilt arms with the front and rear walls of the container as claimed”. In the judge’s view, however, “lock” is an ordinary English word that would be understood by the skilled addressee and locking mechanisms would be well known to the skilled person. Furthermore, “freight” as used in the phrase “freight container” was also sufficiently certain in meaning.
Estoppel by acquiescence
Fabcon argued that, since Ward had not replied to Fabcon’s May 2011 letter, Ward had implicitly permitted Fabcon to continue investing and building its tipping apparatus business (in reliance on the implicit permission) such that now “it would be unconscionable for the Claimant to deny that the manufacture and sale of the Defendant’s apparatus is lawful and does not infringe the Patents”.
The judge, having stated that the “parties in this case have given me notably little assistance on the law in this area” first considered the authorities. A key point arising from this was that, although estoppel by acquiescence “can be founded on mere silence from the right owner, the Claimant’s relevant conduct must consist of its failure to disabuse the Defendant of a mistaken belief”. As the judge further stated, “That requires the Claimant to know about it”.
The burden is therefore on the Defendant to show:
- that it acted in a mistaken belief as to its rights; and
- that the Claimant failed to assert its rights even though the Claimant knew both of the Defendant’s belief and the true position.
In the instant case, the Judge found there was unchallenged evidence that Fabcon acted in a mistaken belief that, by not replying to the May 2011 letter, Ward accepted that Fabcon’s apparatus was non-infringing. However, “the Defendant is not able to satisfy the court that the Claimant knew of this mistaken belief” as there was no evidence in support of this. In particular the judge did not agree with an argument (put by Fabcon’s counsel after conclusion of the trial but before the final order hearing) that, since Fabcon’s May 2011 letter stated “if we have not heard from you within fourteen (14) days… we shall consider the matter to be closed”, Ward must have realised that Fabcon assumed its apparatus was non-infringing and would continue to assume this if it had no response from Ward.
Instead, the judge decided, it was “more likely that the Claimant would have understood that if it did not reply, the Defendant would make its own decision about the risks of proceeding in the face of an unresolved accusation of patent infringement”. In view of this, the Defendant’s claim of estoppel by acquiescence failed.
A copy of the judgment can be found here.