Decoding the role of claim construction in adjudicating patent infringement suits

In a recent case before the Delhi High Court, the Court rejected the plaintiff’s application for an interim injunction for infringement on the grounds that the plaintiff’s case had failed to meet the triple test for the grant of injunction and the balance of convenience strongly favoured the defendants.

Brief background

The plaintiff, Guala Closure SPA, a multinational company, was engaged in the manufacture of closures for spirits, wines, mineral water beverages, olive oil etc. The plaintiff was, inter alia, the owner of the patent No. IN’522, titled ‘Tamper- Evident Closure with Tear Off Seal” [suit patent].  The plaintiffs patented products globally, and their products manufactured in India were exported worldwide.

The defendants were also manufacturers of closure seals, including tamper-proof security caps. They launched a new range of closures for which they held a valid patent. However, the plaintiffs alleged that this new range of closures infringes on their patent.

The plaintiffs issued a cease and desist notice, which was contested by the defendants. 

Subsequently, the plaintiffs filed the present suit and sought an interim injunction.

The submissions of the parties

The plaintiffs outlined the features of the suit patent and demonstrated their similarity to the defendants’ product. The plaintiffs argued that despite the additional features introduced by the defendants, the infringement is evident when the suit patent is mapped onto the defendants’ product.

The defendants highlighted the differences between their closures and the plaintiffs’ closures and asserted that these variations were crucial for claim construction.  The defendants also submitted that they have sold over 124 crore pieces of closures till 2023, whereas the plaintiffs have only filed purchase orders of 1,00,000 pieces, post the filing of the suit.  

The defendants claimed that they have obtained the technology from a company and the inventor has assigned the rights in favour of the defendants. The defendants relied upon the agreement entered into with the company and an affidavit from the inventor to support their contention.

It was the plaintiff’s case that the differences between the two products are irrelevant and the same would still constitute infringement. They contended that, according to the settled legal position with respect to the patented product, a third party could obtain an improvement patent only with the consent of the original patentee, which the defendants failed to obtain.

The plaintiff further averred that the balance of convenience is in their favour as the defendant had an obligation to clear the way before manufacturing the infringing product as they had notice of the plaintiff’s patent.

In response, the defendant reiterated that the differences are essential features of both the claims of the suit patent and their own patent.  They contended that since they are implementing their own patent, there cannot be any infringement of the plaintiff’s patent.

Court's analysis

After hearing the parties, the Court observed that the claim construction is typically the first and most crucial step in adjudicating patent infringement suits, especially when confronted with products like tamper-evident closures which are based on mechanical features.  

The Court referred to Chapter 9 - 'Construction of the Specification and Claims’ - from Terrell on the Law of Patents, which emphasizes that determining the actual scope of the claims in complete specifications is one of the most significant issues in patent litigation. Once the scope of the claims is clarified, questions regarding infringement and invalidity are often swiftly resolved. Therefore, it is essential for patentees to assert their claims in a manner that is broad enough to cover infringement while not excessively broad to avoid coverage by prior art.

On the contrary, it was highlighted that defendants employ a ‘squeeze’ argument, often claiming that if a claim encompasses their activities, it must also encompass prior art. This highlights the pivotal role of claim construction in patent litigation, shaping the foundation for determining infringement and assessing patent validity.

The Court also relied upon Rule 2(c) of the High Court of Delhi Rules Governing Patent Suits which defines ‘Claim construction brief.’ As per this provision, claim construction can be understood to be the process of breaking down the construction of each of the terms contained in the claims, their meaning thereof, as also the overall scope and effect of all the claims relied upon.

The Court reiterated that establishing infringement requires two steps: construing the claims and determining whether the infringing product falls within the scope of the construed claims.

The Court compared the two patents and noted that there were fundamental differences and observed that the characterisation and purpose itself of the suit patent were different from the defendants’ closure. The claimed elements of the independent claim 1 of the suit patent did not map onto the defendants’ closure.

The Court acknowledged that tamper-evident closures are well-known in the market and can be implemented in various ways. A monopoly cannot be claimed on the manufacture and sale of tamper-proof seals in general, but only on the patented tamper-proof seal.

The Court further noted that while both the plaintiff’s patent and the defendant’s patent pertain to closures, they possess similar yet distinctly different features. Despite their shared subject matter, their construction and structural attributes differ.

The Court considered the fact that the plaintiff’s patent was cited as the prior art in the examination report of the corresponding EPO application of the defendant’s, and the same was granted after overcoming the objections in itself demonstrates the differences in both the closures.

The Court opined that prima facie, the defendant’s product could not be termed as merely an improvement over the plaintiff’s basic patent but was a non-infringing product as there were disparities between the plaintiff’s patent claim and the defendants’ product which elucidated clear demarcation and absolved the defendants of any allegations of infringement.

Moreover, the Court considered the balance of convenience to be in favour of the defendants, given their established business producing closure products, which would be jeopardized by a finding of infringement.

Further, in response to the plaintiff’s argument that if the defendant’s patents are indeed improvements over the suit patent, they would still require permission, the Court opined that this issue could only be resolved through a full trial, not at the interim stage.

Ultimately, the Court dismissed the request for an interim injunction, holding that prima facie, there is insufficient evidence to establish a case of infringement.

About the authors: Mahua Roy Chowdhury is the Managing Partner of Royzz & Co. Muthu Pandi is a Partner at the Firm.

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