he issues on appeal was whether the respondents proved direct infringement of the patent by the appellants. Section 45(1) of the Patents Act 57 of 1978 deals with the effect of a patent. The test for infringement under section 45(1) involves a two­stage inquiry. Firstly, the claims must be properly construed, including the ascertainment of the essential integers, then the infringing article or process must be considered. To constitute infringement the article or process must take each and every one of the essential integers of at least one of the claims. If it does not, there is no infringement