Patent Specification Drafting: Description, Claims, Abstract and Unity of Invention
Description
The description must disclose the invention clearly enough for a person skilled in the art to perform it, which is the sufficiency requirement. Good practice follows a structure: title, technical field, background, summary, brief description of drawings, detailed embodiment or embodiments, and industrial applicability. Include the problem solved and the technical effect; this supports inventive step and claim construction. Avoid trade marks and relative terms unless defined.
Claims
Claims define the monopoly. They must be clear, concise and supported by the description. Independent claims should contain the minimum features needed to solve the technical problem; dependent claims add fallbacks. Use two-part form (precharacterising and characterising) where appropriate, but it is not mandatory. Functional language is acceptable if the specification provides adequate support and the claim is not unduly broad.
Abstract and unity
The abstract is for technical information only and must not be used to interpret scope. Unity of invention requires one invention or a single general inventive concept. Separate inventions need separate claims or divisional applications.
Worked example
A specification claims a bottle with a cap and a separate claim to a method of filling the bottle using a different machine. The examiner raises unity. Reasoning: the bottle and the filling method share no single special technical feature; the method solves a different problem (filling speed) from the cap (leak prevention). Either delete the method claim or file a divisional.
Traps
- Drafting claims broader than the disclosure, causing lack of support.
- Relying on the abstract to cure ambiguity.
- Mixing embodiments into one claim without a common inventive concept.
- Omitting industrial applicability.