Guide to construction

Avoid importing gloss or re-drafting claims

2.43 While the description and claims should be read together also taking into account special meanings, care should be taken not to import a gloss or rewrite the claims by relying on the limitations in the description (First Currency v Mainline [2008] 1 SLR 335). This is not the intention of taking a purposive approach to construction. This was affirmed by Rubin J in Flexon (Pte) Ltd v Bean Innovations Pte Ltd and another [2000] SGHC 219, where he cited Lord Russell of Killowen in Electric & Musical Industries, Ltd v Lissen Ltd [1938] 4 All ER 221 at 227:

“I know of no canon or principle which will justify one in departing from the unambiguous and grammatical meaning of a claim and narrowing or extending its scope by reading into it words which are not in it, or which will justify one in using stray phrases in the body of the specification for the purpose of narrowing or widening the boundaries of the monopoly fixed by the plain words of a claim.”

2.44 For example, if the ordinary meaning of the term “slit” is a long narrow opening, then it would not be appropriate to read this in a narrower manner based on the embodiments given in the specification (Fabio Perini SPA v LPC Group plc & others [2010] EWCA Civ 525). Similarly if the description gives certain preferred ranges or embodiments for a feature in a claim, then these should not be read into the claim (unless they clearly indicate a special meaning). However, if a term in the claim could only be read to take a particular meaning, then it would be permissible to read the claim more narrowly (Glatt’s Application [1983] RPC 122).