Bishwanath Prasad Radhey Shyam v. Hindustan Metal Industries (1979, Supreme Court of India)

A foundational Indian patent law ruling defining novelty, inventive step, and the test of obviousness.

Summary :

This case is one of the earliest and most influential Supreme Court judgments interpreting India’s patentability requirements. The dispute involved a patent granted for an improved pressure cooker lid mechanism. The defendant argued that the invention lacked novelty and was obvious to a person skilled in the art. The Supreme Court used this opportunity to lay down clear principles on what constitutes an invention, what qualifies as inventive step, and how obviousness should be judged.

Facts of the Case :

Hindustan Metal Industries held a patent for a pressure cooker safety device claiming improved locking and sealing. The rival party, Bishwanath Prasad Radhey Shyam, manufactured a similar cooker and challenged the validity of the patent. He argued that such mechanisms were already known in prior art and that the alleged improvement did not amount to a real invention. Evidence showed that several earlier cookers already had comparable safety-locking features.

Court Findings / Reasoning :

The Supreme Court held that the patented device did not demonstrate any significant inventive step. The improvement was merely a workshop modification, something a skilled technician could easily arrive at based on existing designs. The Court emphasized that a patent cannot be granted for trivial improvements or routine engineering adjustments. For an invention to qualify, it must show a new technical advance or a non-obvious solution. The Court clarified that obviousness should be tested from the viewpoint of a skilled person, not a layperson.

Suggestions / Practical Lessons :

Patent applicants must ensure that their claimed invention genuinely exceeds known prior art and is not just an incremental or predictable modification. This judgment remains a guiding standard for evaluating patent validity in India and is frequently cited in modern patent disputes.

Judgment :

The Supreme Court invalidated the patent, holding that the invention lacked novelty and inventive step, and was obvious to a person skilled in the field.