Explosive argument shows every word counts in a patent claim

In the matter of African Explosives v Sasol Dyno Nobel, the Commissioner of Patents, seated in Pretoria in South Africa, was tasked to adjudicate whether two amendments of the claims of Sasol’s patent should be allowed, or set aside.

The patent in question is South African patent number 1991/2194, entitled “Low-energy blasting initiation system and surface connection thereof”. The patent was granted on 29 January 1992, with the specification as originally filed. The Registrar of Patents granted the first amendment on 14 August 1992, and the second amendment on 25 May 2004.

In bringing the application, African Explosives contended that the first amendment should be set aside because it fell foul of section 51(7) of the Patents Act No. 57 of 1978. Section 51(7) stipulates that: “No amendment of a complete specification which has become open to public inspection after the publication of the acceptance of the specification in terms of section 42 shall be allowed if the specification as amended would include any claim not wholly within the scope of a claim included in the specification before amendment.”

Werner van der Merwe is an attorney at DM Kisch