Summary
The Delhi High Court rejected Jain Irrigation’s counterclaim challenging the validity of Dura-Line’s patent.
The Court upheld the patent, finding it novel, inventive, and sufficiently disclosed.
This post is Part 2 of the discussion on the Delhi High Court’s judgment dated 19th May 2025 in Dura-Line India Pvt. Ltd. vs. Jain Irrigation Systems Ltd. This post focuses on the counterclaim filed by Jain Irrigation, which challenged the validity of Dura-Line’s patent and sought its revocation under the Patents Act, 1970.
Issues in the Counterclaim:
i. Whether, for the reasons stated in the counterclaim, Dura-Line’s patent is liable to be revoked?
ii. Relief.
Court’s analysis:
Novelty:
Citing Glaverbel SA v. Dave Rose and Ors, Ericsson vs Lava, and General Tires & Rubber Co. v. Firestone Tyre & Rubber Co. Ltd, the Court found that none of the cited prior art references individually disclosed all the claimed features in combination. Further, the Court stated that a prior art document could destroy novelty only if it contained clear and unmistakable instructions that would inevitably lead a skilled person to arrive at the same invention. Since no such disclosure was found, the Court concluded that Claim 1 of the suit patent was not anticipated, and the objection under Section 64(1)(e) was accordingly rejected.
Inventive step:
To assess inventive step under Section 64(1)(f), the Court applied the five-step test from F. Hoffmann-La Roche v. Cipla, based on the Windsurfing/Pozzoli framework, which evaluated the Person Skilled in the Art (PSA), inventive concept, common general knowledge, differences from prior art, and whether those differences would be obvious without hindsight. Citing Biswanath Prasad Radhey Shyam judgement, the Court reiterated that patents must go beyond routine improvements. The PSA was identified as a mechanical or polymer engineer familiar with pipe systems. The Court observed that the co-extrusion of a tracer wire onto the outer surface of a non-metallic fluid pipe, encased in polymer, enabling leak detection without compromising structural integrity, formed the inventive concept. It further noted that none of the cited references taught the configuration adopted by Dura-Line. Citing KSR v. Teleflex, the Court also observed that mosaicing was allowed only where the prior art clearly motivated the combination, which was not the case with Dura-Line. Citing Guangdong OPPO v. Controller of Patents and Novartis v. Mylan, the Court reiterated that a linking rationale must exist between prior arts, and that the “obvious to try” argument in the absence of a reasonable expectation of success should be rejected.
Finding no teaching or suggestion of the specific co-extruded arrangement in the cited prior art, and noting the Defendant’s reliance on hindsight, the Court held that the claimed invention was not obvious and involved a technical advance, thus rejecting the inventive step objection under Section 64(1)(f).
Sufficiency of disclosure under Sections 64(1)(h) and (i) of the Patents Act:
The Court, citing Mr. Aloys Wobben v. Vestas and Farbwerke Hoechst v. Unichem, observed that sufficiency did not require exhaustive data or re-teaching known techniques, but only enough disclosure to enable a skilled person to perform the invention. Since co-extrusion and impedance-based detection were established methods and the structural configuration was adequately disclosed, the Court found the specification enabling. The Court also highlighted the inconsistency in the Defendant’s reliance on a vague NHAI document as prior art while alleging insufficiency. With no evidence of failed implementation and the Defendant’s own product reflecting the claimed invention, the Court held that the claims were clearly worded, fairly based, and sufficiently supported.
Section 64(1)(m):
The Court, citing Maj. (Retd.) Sukesh Behl v. Philips, held that revocation required clear evidence of fraud, not mere omissions or technical disagreements. The Court noted that no such evidence was shown at Dura-line’s end, i.e., there was no false statement, concealment of prior art, or intent to mislead. The Court noted that Dura-Line did not claim novelty in co-extrusion and the patent was granted after due examination and therefore the Court found the objection under Section 64(1)(m) to be unsubstantiated.
Conclusion:
The Court therefore dismissed Jain Irrigation’s challenge to validity and upheld the patent. As a result, the counterclaim seeking revocation of the patent was dismissed, and no further relief was granted to Jain Irrigation.
Relevant paragraphs:
85. The assessment of inventive step entails a structured, multi-stage analysis that traces its origin to the four-step framework articulated in Windsurfing International Inc. v. Tabur Marine Limited,15 and refined in Pozzoli Spa v. BDMO SA16 through the identification of the PSA. This approach was further tailored by the Division Bench of this Court in F. Hoffmann-La Roche Ltd. v. Cipla Ltd.,17 which distilled a five-step test for evaluating inventive step, drawing from the Windsurfing/Pozzoli framework.
The Five-Step Test: F. Hoffmann-La Roche Ltd. v. Cipla Ltd.
86. The five-step test, applied across patent cases post-2015, remains a touchstone to determine obviousness:
“Step No. 1: To identify an ordinary person skilled in the art,
Step No. 2: To identify the inventive concept embodied in the patent,
Step No. 3: To impute to a normal skilled but unimaginative ordinary person skilled in the art what was common general knowledge in the art at the priority date,
Step No. 4: To identify the differences, if any, between the matter cited and the alleged invention and ascertain whether the differences are ordinary application of law or involve various different steps requiring multiple, theoretical and practical applications,
Step No. 5: To decide whether those differences, viewed in the knowledge of alleged invention, constituted steps which would have been obvious to the ordinary person skilled in the art and rule out a hindside approach”
87. This Court must step into the shoes of a skilled artisan and not the inventor, and then evaluate whether the invention emerges from a routine progression or a creative leap.
99. The assertion that the Plaintiff failed to include empirical data on technical advantage in the specification does not, ipso facto, negate inventive step. The statutory definition of Section 2(1)(ja) of the Patents Act permits either technical advance or economic significance. The specification highlights simplification of installation, prevention of cable damage, and the avoidance of pipe-wall compromise. These are commercial and operational advantages that support inventive merit, even if not reduced to numerical data.
Obviousness Hindsight Bias
100. Obviousness is not a license to dissect an invention into known parts and reassemble them retrospectively. The prohibition against hindsight bias, repeatedly emphasised in judicial decisions, guards precisely against such mechanical analysis. In evaluating whether the Suit Patent is obvious, this Court must remain vigilant against the use of hindsight bias, a cognitive trap that distorts legal analysis by judging the state of prior art with knowledge of the invention already in hand.
101. Hindsight bias refers to the tendency to view past events as having been more predictable than they actually were. In the context of patent law, it manifests when the claimed invention is dissected into known components, and then those components are re-combined with the benefit of knowing the invention’s outcome, thereby undermining the statutory requirement of a true inventive step. Thus, the test for inventive step must not be applied in a retrospective manner.
Citation: CS(COMM) 245/2017 & CC(COMM) 54/2017, I.A. 7004/2013
Available at: https://indiankanoon.org/doc/54191432/
Article review by Dr. Neetha Mohan and Accessibility review by Mr. Gaurav Mishra
