Stretchline, a fabric manufacturer which claims to produce enough elastic each year to wrap around the world 30 times' over, has succeeded in its High Court claim relating to patented underwire bra technology against retailer H&M.
Long ago, in 2009, Stretchline sued H&M for patent infringement in relation to UK patent GB 2,309,038. The patent covered the use of fusible yarn in the manufacture of the fabric tube which contains the wire in underwired bras. The use of the fusible yarn helps render the fabric tube less likely to be penetrated by the wire which, as anyone knows who has ever worn an underwired bra, can be rather ouch-inducing!
H&M denied infringement and raised the invalidity of the patent by way of defence and counterclaim. Stretchline also brought US proceedings against H&M on the related US patent.
In 2011 the parties compromised the UK and US proceedings by way of a "full and final" settlement agreement. In brief (the agreement is detailed but we will limit ourselves to the broad principles) H&M was to cease selling the infringing articles and would not challenge the validity of the patents in suit and would pay Stretchline a sum of money towards its costs. The parties would enter into a supply agreement and the UK proceedings would be stayed save for the need to enforce the terms of the agreement.
However, in 2012, Stretchline became suspicious that H&M was yet again dealing in infringing bras and in March 2013 began these proceedings.
Stretchline sued H&M for (a) breach of contract; and (b) infringement of the patent. H&M (i) denied breach of contract, (ii) denied infringement; and (iii) challenged the validity of the patent both by way of defence to the infringement claim and by way of counterclaim.
H&M claimed that Stretchline had "stretched" the construction of the patent in asserting that its new bras infringed the patent or that their sale constituted breach of contract and therefore it wasn't bound by the terms of the agreement.
In August 2014 Stretchline issued an application for an order to strike out H&M's challenges to the validity of the patent asserting that it had forever compromised its ability to raise such issues by virtue of the terms of the settlement agreement.
H&M did not raise any challenge to Stretchline's plea of infringement .
In October 2014 Mr Justice Sales in the High Court of the Chancery Division (not the Patents Court) found for Stretchline and held that H&M's case, insofar as it sought to raise issues of validity of the patent, should be struck out because H&M had compromised its ability to raise such issues by virtue of the terms of the settlement agreement.
H&M was not to be deterred and appealed Mr Justice Sales' decision to the Court of Appeal resulting in a unanimous judgment given by Lord Justice Kitchin on 22 May 2015 that Mr Justice Sales was right. Please see our report here on the judgment.
The case therefore fell to be decided by the High Court in relation to the breach of contract claim (Stretchline, upon reading the judgment of the Court of Appeal wisely elected to drop its infringement claim).
Mr Justice Carr found that the new bras sold by H&M fell within the scope of Stretchline's patent. Key to this finding was his construction of the patent. In consequence, H&M had breached the terms of the settlement agreement previously entered into by the parties.
The common general knowledge
The judge noted that the common general knowledge at the priority date included the following:
- Fusible yarns had been well-known for many years. The normal function of such yarns was, on melting and cooling, to bond fibres together within a fabric in order, for example, to strengthen the material. It was known to act as an adhesive.
- The skilled person would have known that it was impossible to form a continuous, discrete layer or liner from fusible yarn on a woven fabric or in a tubular fabric. Further, because of the additional cost of such material, it would not make commercial sense to try to form a layer of such material, given that simply including a small quantity of the fusible yarn as an adhesive within the structure of the fabric would increase its resistance to penetration, and there was no reason to believe that a discrete layer would be any better.
Construction: the approach
Carr J said:
"...the question is what the person skilled in the art would have understood the patentee to be using the language of the claim to mean. I bear in mind that the patentee is using language to make a communication for a practical purpose and that an interpretation which gives his language a meaning different from the way it would have been understood by the people to whom it was actually addressed is liable to defeat his intentions."
Construction: the decision
The judge held it was clear, from the description of the invention contained in the specification of the patent, that it was the tubular fabric of the invention, as opposed to a discrete part of it, which achieved increased resistance to penetration.
The claims required that the fusible yarn is (or is capable of being) the cause, or trigger, for formation of the penetration barrier, which comprises the remaining yarns as a composite structure. This did not require the fusible yarn to form a discrete, continuous layer, which the skilled person would know was impractical. Furthermore, it was clear from the description, and from common general knowledge, that an absolute barrier to penetration was not required. Fusible yarn was used to achieve a higher resistance to penetration than would be the case in conventional tubular fabric, in order to address the problem of underwire protrusion.
Mr Justice Carr then turned to H&M's contention that the skilled person would appreciate that upon this construction, the invention would be invalid in the light of common general knowledge, as bonding yarn would be used for its well-known purpose of bonding. H&M argued that, since this would be a "foolish reading", it should be rejected.
The judge disagreed. This was another attempt, in his view, to introduce a squeeze between non-infringement and invalidity, rather than an issue of real relevance to construction, and it was precluded by the Court of Appeal's 22 May 2015 ruling. If validity had been in issue, he would have reached the same conclusion on construction, even if doing so would have led to a finding that the patent was invalid.
However, upon the evidence before the court, it was the judge's view that the patent would not be found invalid based upon the common general knowledge. This was because while the evidence established that fusible yarn was well-known at the priority date, it did not establish that its use to increase penetration resistance in tubular fabric was common general knowledge at that date. On the contrary, said the judge, this appeared to be a new use of a known material to solve a long-standing problem. So H&M's non-infringement/invalidity squeeze appeared to fail.
Upon the construction accepted by the court, infringement followed. The judge said that no explanation had been offered as to why fusible yarn was woven into the weft of all the alleged infringements, other for the purpose of increasing resistance to penetration of the tubular fabric by the underwire.
Each of H&M's Devsel, Rimteks and Takefast bras complained of therefore fell within the claims of Stretchline's patent and the sale of such bras by H&M was in breach of the settlement agreement.