The Delhi High Court, recently, granted a permanent injunction in favour of SNPC Machines Private Limited & Ors. (“Plaintiffs”) restraining Mr. Vishal Choudhary (“Defendant”) from manufacturing and selling brick-making machines similar to the Plaintiffs’ patented brick-making machines.
The Plaintiffs argued that the Defendant’s machines substantially resembled the Plaintiffs’ machines, thereby infringing on the Plaintiffs’ suits patents. The Plaintiffs also claimed that the substituted element in the Defendant’s machines was performing the same work and achieving the same result as that of the Plaintiff’s machine. The Plaintiffs, accordingly, invoked the Doctrine of Equivalence which allows a court to hold a party liable for patent infringement if the infringing device or process is equivalent to the claimed invention, even if it doesn't fall within the literal scope of a patent claim.
The Defendant, on the other hand, took the defence of ‘all elements rule’, asserting that the product allegedly infringing the suit patent must contain every claim element, and if any element is missing, it does not constitute infringement.
The court ruled that an infringer cannot escape by arguing that certain elements of the suit patents are not present in the Defendants’ product. To establish a possible infringement, the ‘pith and marrow’ test is to be used alongside doctrine of equivalence. The pith and marrow test, requires courts to look beyond the literal wording of a patent claim and focus on what the invention does. The court emphasised that infringement should be assessed on the core functionality of the invention rather than minor variations in claim elements.
The court applied the doctrine of equivalence and observed that the substituted element in the infringing product performed substantially the same function in substantially the same way to achieve substantially the same result. Therefore, an interim injunction is granted in favour of the Plaintiff prohibiting the defendant from manufacturing and selling brick-making machines. The Court also restrained the Defendant from infringing the Plaintiffs’ copyright in any literature or specification pertaining to the suit patents.
SNPC Machines Private Limited & Ors. vs. Mr. Vishal Choudhary, [CS(COMM) 431/2023, Delhi High Court, 05th March 2024]