Laxmi Dutt Roop Chand v. Nankau And Ors.

Buying a patent can feel like buying a fortress — solid, protected, and ready to defend your business. But what if the fortress was built on sand? In a landmark dispute over a process for manufacturing hollow wares, a partnership firm discovered that holding a registered patent assignment is not the same as holding a valid patent. This case is a powerful reminder for founders and IP holders that ownership and validity are two very different battles.

The plaintiff in this case was a partnership firm that had stepped into the shoes of the original patentee by purchasing Patent No. 42514 of 1950, which covered a process for manufacturing hollow wares. Believing they held a legitimate and enforceable right, the firm sued the defendants, accusing them of infringing the patented process. The defendants, however, did not simply defend themselves — they went on the offensive. They filed a counter-claim seeking revocation of the patent itself, arguing that it suffered from fundamental flaws, including a lack of inventive step and prior public use before the patent was granted.

The plaintiff firm argued from a position of ownership: they had lawfully acquired the patent from the original patentee, and as the registered assignees, they were entitled to enforce it against infringers. The defendants countered that ownership was irrelevant if the patent itself was never valid to begin with. They challenged the very foundation of the patent — its novelty and utility — and pointed to prior use as evidence that the invention was not new. The legal friction centered on a critical question: can a registered assignee be treated as a patentee for the purposes of a revocation claim, even if they did not originally invent the process?

The court sided with the defendants. It found that the patent was neither novel nor useful, striking at the very heart of what makes a patent valid. Crucially, the court held that a registered assignee is considered a patentee under the Act, which meant the revocation counterclaim was perfectly maintainable against the plaintiff firm. The patent was revoked, and the defendants' counterclaim succeeded, leaving the plaintiff firm with neither a valid patent nor a successful infringement claim.

For founders and IP professionals, this case delivers a hard truth: acquiring a patent — whether through purchase, assignment, or transfer — does not guarantee its validity. Before investing in a patent, conduct thorough due diligence on its novelty, inventive step, and utility. A registered assignee may be treated as a patentee under the law, which means revocation claims can be directed against you just as easily as against the original inventor. Ownership is only as strong as the invention it protects.