High Court Establishes Obviousness Over McDonald in Expandable Garden Hose Patent Case

Introduction

The case of E Mishan & Sons, Inc (t/a Emson) v. Hozelock Ltd & Ors ([2019] EWHC 991 (Pat)) was adjudicated in the England and Wales High Court (Patents Court) on April 17, 2019. The core of the dispute revolved around patent infringement and the validity of Emson's patents concerning expandable garden hoses. Emson, as the exclusive sub-licensee of the patents GB 2 490 276 and EP (UK) 2 657 585, alleged that Hozelock Ltd infringed upon these patents with its Superhoze 1 and Superhoze 2 products. Hozelock denied the infringement and challenged the patents' validity on grounds of obviousness, particularly over prior art represented by the Ragner and McDonald patents.

Summary of the Judgment

Justice Nugee delivered an extensive judgment addressing both the infringement claims and the validity of Emson's patents. The court concluded that while the patents were not invalidated by prior use or lack of inventive step over the Ragner patent, they were deemed invalid due to obviousness over the McDonald patent. Furthermore, the judgment affirmed that both the Superhoze 1 and Superhoze 2 products by Hozelock infringed the relevant claims of the patents, assuming the patents' validity. The court also dismissed Hozelock's attempt to establish indirect infringement through the alleged failure of joiners in the Superhoze hoses.

Analysis

Precedents Cited

The judgment extensively referenced several pivotal cases and statutes that shaped the legal reasoning:

Blue Gentian LLC v Tristar Products (UK) Ltd [2013] EWHC 4098 (Pat): Established that claims of the GB 276 patent were novel and non-obvious over prior art Ragner and McDonald.
Actavis UK Ltd v Eli Lilly & Co [2017] UKSC 48 (Actavis): Clarified the approach to infringement, introducing a two-step analysis involving claim interpretation and the doctrine of equivalents.
Icescape Ltd v Ice-world International BV [2018] EWCA Civ 2219 (Icescape): Reinforced the Actavis principles regarding claim interpretation and the importance of the inventive concept.
Windsurfing International Inc v Tabur Marine (Great Britain) Ltd [1985] RPC 59 (Windsurfing): Laid out the structured approach to assessing inventive step.
Pozzoli SpA v BDMO SA [2007] EWCA Civ 588 (Pozzoli): Reformulated the Windsurfing analysis into a structured approach for assessing inventive step.
Merrell Dow Pharmaceuticals Inc v H. N. Norton & Co Ltd [1996] RPC 76 (Merrell Dow): Interpreted what constitutes making information available to the public.
Same Invention G02/98 [2002] EPOR 167: Defined priority rights and their implications for patent claims.
Technetix BV v Teleste Ltd [2010] EWCA Civ 525 (Technetix): Discussed the Formstein defense and its applicability in English law.

Additionally, the judgment referred to statutory provisions such as the Patents Act 1977 (PA 1977), specifically sections concerning priority ([s.5(2)]), state of the art ([s.2(2)]), inventive step ([s.56]), and the doctrine of equivalents.

Legal Reasoning

The court's legal reasoning can be dissected into several key components:

Identification of the Skilled Person and Common General Knowledge: The court determined that the skilled person in this context was a general hose designer with experience in both garden and technical hoses. This broad characterization was crucial in assessing both obviousness and infringement.
Inventive Concept: Central to the validity of the patents was the inventive concept of having an expandable hose comprising an elastic inner tube and a non-elastic outer tube, unattached except at the couplers, allowing for expansion and contraction under pressure.
Assessment of Obviousness: The court found the patents invalid based on obviousness over the McDonald patent. Unlike Ragner, which did not sufficiently anticipate the inventive concept, McDonald disclosed a similar expandable hose mechanism that, when adapted, rendered Emson's patents obvious to the skilled person.
Infringement Analysis: Applying the Actavis approach, the court concluded that both Superhoze 1 and Superhoze 2 infringed the patents. Despite Hozelock's arguments regarding the attachment points and elasticity of the outer tube, the court held that these variations fell within the scope of the patents under the doctrine of equivalents.
Doctrine of Equivalents and Formstein Defense: The court addressed attempts by Hozelock to argue for a defense akin to the Formstein principle but ultimately did not find merit in those arguments in this particular context.

A significant aspect of the judgment was the court's emphasis on the structured analysis for obviousness, as reformulated in the Pozzoli case. This approach requires a methodical comparison between the patent's inventive concept and the prior art, assessing whether the differences constitute obvious steps to the skilled person.

Impact

This judgment has noteworthy implications for patent law, particularly in the assessment of obviousness and infringement:

Obviousness Over Prior Art: By invalidating the patents over the McDonald prior art, the court reinforced the stringent standards required to establish non-obviousness, especially when prior art closely mirrors the inventive concept.
Doctrine of Equivalents: The affirmation that variations falling within the doctrine of equivalents can still constitute infringement underscores the need for patentees to draft claims with precision to cover potential equivalents.
Priority Claims: The court's interpretation of priority rights, particularly the emphasis on what is "directly and unambiguously" disclosed in the priority document, offers guidance on how priority disputes may be navigated in future cases.
Formstein Defense: Although not definitively addressed, the court's handling of Hozelock's arguments regarding indirect infringement suggests a cautious approach towards introducing robust equivalents defenses outside established doctrines.

Overall, the judgment serves as a precedent for assessing both the validity and infringement of patents in cases where prior art presents considerable similarities to the patented invention.

Complex Concepts Simplified

1. Inventive Step (Obviousness)

An inventive step refers to the requirement that a patent's invention must not be obvious to a person skilled in the relevant field. If the inventive concept can be easily deduced from existing knowledge and prior art, the patent may be invalidated for lacking an inventive step.

2. Doctrine of Equivalents

This legal principle allows a court to hold a party liable for patent infringement even if the infringing product or process does not fall within the literal scope of a patent claim but performs substantially the same function in substantially the same way to achieve the same result.

3. Priority Date

The priority date is the date from which the patent holder can claim rights. It is typically the filing date of the earliest patent application related to the invention. Determining the priority date is crucial as it establishes the benchmark against which prior art is assessed.

4. State of the Art

This encompasses all knowledge and inventions that were publicly available before a specific date (usually the priority date of the patent application) that is relevant to the invention's field. It serves as the baseline for assessing novelty and inventive step.

5. Formstein Defense

Originating from German patent law, this defense argues that even if a product falls within the literal scope of patent claims, if the variation is trivial or obvious to make, it should not be considered infringement. While not formally recognized in English law, the judgment hints at its conceptual relevance.

Conclusion

The High Court's judgment in E Mishan & Sons, Inc (t/a Emson) v. Hozelock Ltd & Ors [2019] EWHC 991 (Pat) serves as a significant marker in patent law, particularly concerning the doctrines of obviousness and infringement. By invalidating the patents over the McDonald prior art and confirming infringement under the doctrine of equivalents, the court underscored the necessity for patentees to ensure their inventions are not only novel but also non-obvious in light of existing technologies.

Additionally, the decision elucidates the complexities involved in priority claims and the interpretative approaches for patent claims, emphasizing the interplay between the patent's specification and its claims. The handling of the Formstein-like arguments, albeit not fully settled, opens avenues for future discourse on equivalent defenses in English patent law.

For practitioners and stakeholders in the patent domain, this judgment reinforces the importance of comprehensive prior art searches, precise claim drafting, and a robust defense of the inventive step to safeguard patent validity and enforceability.