The claims define the scope of the invention and must be read along with the complete specification.

Background

The subject matter of the patent in this case is an “Air Tight Fuel Cap”. The patent, registered as patent no. 427110, involves a fuel cap designed to be secured intermittently to a fuel filler neck attached to an inlet of a feed oil pipe. The key feature of this fuel cap is that each of the locking projections of the cylindrical locking member is provided with a pair of beams on an inner surface that terminate at a predetermined distance from the bottom end of the locking projections. This predetermined distance is specified to be equal to 10% to 100% of the length of the main circular plate separating the middle portion of the cylindrical body from the bottom portion.

Jay Switches India Pvt Ltd (the Plaintiff) brought the action against Sandhar Technologies Ltd (Defendant)

Plaintiff’s Arguments:

1. Infringement of Patent: The plaintiff argued that the defendants’ fuel cap product infringes their patent no. 427110, titled “Air Tight Fuel Cap.” They claimed that the defendants’ product uses an identical solution to prevent leakage by limiting free space between the beams and the Main Circular Plate (MCP), which is functionally and structurally identical to the plaintiff’s patented design.
2. Claim Mapping: The plaintiff’s alleged that its expert conducted a detailed analysis and claim mapping, which they argue proves that the defendants’ product infringes the Suit Patent. They assert that the defendants’ minor alteration of 0.5 mm in the non-functional part of the MCP is misleading and does not avoid infringement.
3. Engagement Projections: The plaintiff contended that the Engagement Projections (EP) are an integral part of the MCP, and the defendants’ approach of treating them as separate components is incorrect. They argued that the predetermined distance (PD) in the defendants’ product exceeds the claimed range of 10-100% in the Suit Patent.
4. Typographical Error: The plaintiff acknowledged that a typographical error in the positioning of a reference numeral in Claim 1 but argues that it does not amount to misrepresentation.

Defendants’ Arguments:

1. Non-Infringement: The defendants argued that their product does not infringe the Suit Patent because the Predetermined Distance (PD) in their product is 3 mm, while the thickness of the MCP is 2.5 mm. They assert that the PD exceeds the thickness of the MCP, which means their product does not fall within the claimed range of 10-100%.
2. Prosecution History: The defendants emphasized the importance of the prosecution history of the Suit Patent in construing the claims. They argue that the claims should be interpreted based on the amendments and statements made during the prosecution, which establish that the 10-100% range refers only to the MCP and not the EP1011.
3. Distinct Components: The defendants maintained that the MCP and EP are distinct components, and the length of the MCP should not include the EP. They argue that the plaintiff’s reliance on Claim 2 and the specification to include the EP in the MCP is incorrect.
4. Typographical Error: The defendants acknowledged a typographical error in their post-hearing written submissions but argue that it does not amount to an admission of infringement.

Court’s Ruling in the case of focused on the interpretation of Claim 1 of the Suit Patent.

1. The court emphasized that the claims define the scope of the invention and must be read along with the complete specification.
2. The court concluded that the core issue was whether the predetermined distance (PD) in Claim 1 should be interpreted to mean “10% to 100% of the length of the main circular plate along with engagement projections” as argued by the plaintiff, or “10% to 100% of the length of the main circular plate (MCP)” as argued by the defendants.
3. The court found that if the plaintiff’s interpretation was accepted, the defendants’ product would infringe the patent. Conversely, if the defendants’ interpretation was accepted, there would be no infringement of the Suit Patent.
4. Ultimately, the court ruled in favour of the defendants, concluding that the predetermined distance (PD) in the defendants’ product exceeded the claimed range of 10-100% of the length of the main circular plate (MCP), and therefore, the defendants’ product did not infringe the Suit Patent.

The court accordingly dismissed the application for the grant of interim injunction by the Plaintiff.