Bateman Equipment Ltd and Another v The Wren Group (Pty) Ltd

The respondent, The Wren Group (Pty) Ltd, was the registered proprietor of South African patent 93/6167 relating to a process and apparatus for separating solids from liquids using gravity settling. It instituted patent infringement proceedings against the appellants, Bateman Equipment Ltd and Elandsrand Gold Mining Co Ltd. The appellants responded with a counterclaim seeking revocation of the patent on grounds including lack of novelty, obviousness, and lack of clarity. To avoid possible revocation, the respondent applied to amend the patent specification under section 51(9) of the Patents Act 57 of 1978 while litigation was pending. The Commissioner of Patents (Mynhardt J) granted the amendment despite objections. The appellants appealed against the grant of the amendment.

The appeal was dismissed, and the order granting the amendment of the patent specification under section 51(9) of the Patents Act was upheld.

The case is significant for clarifying the distinction between patent amendment procedures under sections 51(1) and 51(9) of the Patents Act. It confirms that 'full reasons' are not a jurisdictional requirement for amendments sought during pending litigation and affirms a pragmatic, non-formalistic approach to patent amendments. The judgment also reinforces established principles on claim clarity and the fair basis requirement in South African patent law.