A quick summary of two relatively recent court decisions in the UK explaining why having a British granted patent now gives you generally greater protection under the newly adopted ‘doctrine of equivalents’ without the limitation of ‘file history estoppel’.
At the end and in view of the above, this article also gives some suggestions to consider when you are now writing a new patent (or having a new patent written for you).
Recent Decision 1:
Excel-Eucan Limited v Source Vagabond Systems Limited
The patent relates to a ‘link-tail’ bag for feeding ammunition to a machine gun:
The single granted independent claim reads:
Shown below(1) are the Link-Tail (top example, and subject of the above claim 1), and the 2017 Bag (lower example, and competitor product); in both cases with the top flap open at the right hand end:
The important bit to notice is that the competitor bag (the ‘2017 Bag’) at the bottom does not have a zipped opening (you can see the zipped opening in the patented ‘Link-Tail’ bag at the top and circled) or indeed any openable closure along its length. If you re-read the claim above, you can see that the ‘openable closure’ is a required feature of the granted claim.
The judge concluded: ‘I am satisfied that the 2017 Bag (ed: competitor product) achieves the same result in substantially the same way as the invention. Both bags can be loaded horizontally and/or vertically and substantially the same result is achieved. In neither case is the openable closure necessary.’ Highlights added.
Granted claim 1 clearly requires ‘an openable closure extending substantially from the first end to the second end’. The court held that this feature is immaterial to the ‘inventive concept’.
Therefore, infringement was found.
This is a positive outcome for the patent owner. A product without all of the features of their granted claim 1 was still held to infringe.
Recent Decision 2:
Icescape Limited v Ice-World International Bv & Ors
Ice-World’s patent is for cooling a mobile ice rink.
To make transport easier, the cooling system of manifolds feeding cooling pipes can be folded up.
The diagram below(2) from Ice-World’s patent shows two ‘elements’ or sections of the Ice-World design (41, 42, each highlighted by a green box). Each section (41, 42) has a main feed pipe or manifold (43, 45, circled in purple) and a discharge manifold (44, 46, also circled in purple).
The feed and discharge manifolds of the two sections (41, 42) are connected to each other via joints 47 and 48 (circled in red) respectively.
As such, the cooling fluid entering the feed manifold (45) of the second section (42) must pass through the feed manifold (43) of the first section (41). The same applies to the discharge manifolds (44, 46), albeit in a reverse direction of flow.
In other words, the ections (41, 42) are considered to be connected in series or one after the other.
Each section (41, 42) also has a number of longitudinal cooling pipes (50, 51, circled in blue) which have a ‘first series’ or bank of pipe sections (68, 68’, 68’’) connected in series with a ‘second series’ or bank of pipe sections (69, 69’, 69’’) by flexible joint members 70 (circled green). The result of the above is that this jointing (70) of the various pipes (50, 51) allows folding of the system to permit easier transport for mobile ice-rink applications.
The variant by Ice-World’s competitor, Icescape, is diagrammatically shown below(2). The arrangement has three ‘elements’ or sections (E1, E2, E3, highlighted as green boxes).
Each section of the competitor’s system has a feed manifold (F3, circled in purple), a discharge manifold (D3, circled in purple) and cooling pipes ‘C’ (circled in blue) extending in parallel with each other.
The cooling pipes ‘C’ comprised foldable joints, which are not visible in the diagram below.
However, Icescape believed that they would circumvent the Ice-World patent if they positioned their sections (E1, E2 and E3) such that the fluid entering the feed manifold (F3, circled in purple) of any of the three sections (E1, E2, E3) did not pass through the feed manifold of any other of the three sections (E1, E2, E3).
In other words, the sections (E1, E2, E3) are in parallel, rather than in series.
As such, in the Icescape arrangement, there is no equivalent to the joints (47 and 48) in the Ice-World patent.
Icescape believed that this separated them sufficiently from the Ice-World patent:
Granted claim 1 of the Ice-World patent was set out in integer form (i.e. as a list) by the judge(2):
“Cooling member (21, 40) for a mobile ice rink provided with:
a feed manifold (43, 45) extending in a transverse direction and a discharge manifold (44, 46), and a number of longitudinal pipes (50, 51) which extend transversely to the manifolds and can be connected at a first end (53, 54) to a manifold (43, 44, 45, 46), two longitudinal pipes (50, 51) in each case being in fluid communication with one another at a second end (60, 61) via a connector (27, 63), so that a fluid path is formed from the feed manifold (43, 45) to the discharge manifold (44, 46) via the two connected longitudinal pipes (50, 51), characterised in that
- the cooling member comprises at least two elements (41, 42), each with a feed manifold (43, 45) and discharge manifold (44, 46) and a number of longitudinal pipes (50, 51) connected thereto,
- wherein each longitudinal pipe comprises at least two rigid pipe sections (3, 12, 16, 24, 68, 69) that are connected to one another via a joint member (4, 13, 17, 25, 70, 132, 133) such that they are fluid-tight, and
- wherein by moving the joint members (4, 13, 17, 25, 70, 132, 133) a first series of parallel pipe sections (68, 68′, 68″) can be placed in a transport position with respect to a second series of parallel pipe sections (69, 69′, 69″) connected thereto, in which transport position the two series of pipe sections (68, 68′, 68″; 69, 69′, 69″) are at an angle with respect to one another or are positioned on top of one another, and can be placed in an operational position in which the two series of pipe sections (68, 68′, 68″; 69, 69′, 69″) extend in the extension of one another,
- wherein the first and the second element (41, 42) can be placed in the operational position alongside one another such that the feed and discharge manifolds (43, 44, 45, 46) of the elements extend in the extension of one another in the transverse direction,
- wherein the feed and discharge manifolds of the two elements are provided with a coupling member (47, 48) to make a fluid-tight connection between the respective feed and discharge manifolds of the first and the second element.”
It was submitted that ‘the key novel and inventive feature of the invention is integer C […] the use of joint members (70, ed: see first image above) which allow the longitudinal pipes to have two configurations, one in which the cooling pipes are extended and the other in which the cooling pipes are folded back on one another. This is the integer which enables the claimed system to work in its intended manner. Integer C is […] the invention.’
The competitor, Icescape, accepted that their design had all of the features of Ice-World’s granted Claim 1 except integers D and E (i.e. they had features A, B and C, but not D and E) due to their parallel arrangement.
On Appeal, it was held that, although the claim must be taken literally to be limited to a ‘series’ connection between the adjacent ‘elements’, a ‘parallel’ connection is an alternative way of implementing the same concept. The difference in the positioning of the elements relative to each other has nothing to do with the core inventive contribution of the patent (the foldability of the cooling pipes 50, 51 and C).
The judge held that ‘there is nothing to suggest that the patentee regarded series connection as essential in any relevant sense’.
The judge also noted that the prosecution history did nothing to alter this view, and as such ‘file history estoppel’ or restricting the scope of the claim based on comments made by the patentee during examination still plays no part in the determination of the inventive concept.
However, the judge nuanced this statement by reinforcing a previous judgement that reference to the prosecution history would be appropriate in two scenarios. The first scenario was where “(i) the point at issue is truly unclear if one confines oneself to the specification and claims of the patent, and the contents of the file unambiguously resolve the point”.
The second scenario is where “(ii) it would be contrary to the public interest for the contents of the file to be ignored”.
The judge illustrated the second scenario as occurring where the patentee had explicitly renounced a variant during prosecution, but later tried to enforce the patent against that very variant.
Therefore, on Appeal, the decision was overturned and the patent was held to be infringed (although it was also held invalid due to an invalid priority claim, but that is beyond the scope of this article’s topic).
Again, this is another positive for the patent owner. The competitor’s product clearly did not have all the features of the granted claim 1. But, the system was held to achieve substantially the same inventive concept, and as such infringement was found.
- In light of these decisions, it seems to make sense to ‘characterise’ your independent claims at the outset with ‘results to be achieved’ type language that explains the intended inventive concept. Even if the claim language is then limited during prosecution, the broad ‘inventive concept’ (or even concepts) remains stated on filing.
- Furthermore, including caveats and examples throughout the patent specification would seem to encourage a broad interpretation of the ‘inventive concept’.
- Having a well-rounded and broad ‘conclusion’ at the end of your description which restates in different language the ‘inventive concept/concepts’ rather than necessarily just specific features also makes sense.
- It is also worth bearing in mind that, although a claim can be infringed, the patent can still be held invalid in light of prior art. With the broader interpretation being given to granted claims, being aware of such prior art therefore now becomes increasingly more relevant.
- The alleged infringer will likely still push for ‘file history estoppel’ or in other words using the examination history to mould or shape the scope of the granted main claims and what the inventive concept should be construed as. It is therefore prudent to be mindful of statements being made during examination. Re-stating the broad inventive concept during examination is a good idea, but not necessarily explicitly designating essential features which are deemed to make up that inventive concept.