In Camworth Technologies Ltd v Videx Wire Products (Pty) Ltd, the Supreme Court of Appeal heard an appeal from the Court of the Commissioner of Patents, where the respondent, Videx, had successfully obtained a declaration of non-infringement in terms of s 69(1) of the Patents Act.

There was no dispute between the parties that the procedural requirements of s 69(1) of the Act were complied with. In terms of that section the patentee had failed to give an acknowledgement of non-infringement. The dispute was whether the Videx product, a preload device or pot used in mining, infringed the Camworth patent by falling within the ambit of any of the claims of the patent.

In order to assess infringement, the patent specification and, more specifically, the patent claims have to be construed. In South Africa, a purposive construction is used, and the patent claims are broken down into their essential integers. Only if all the essential integers of a claim are present in a product, would the product infringe the patent in question.

The Camworth patent comprises seven claims directed towards a preload device, of which claims two to six are dependent on claim one and claim seven is a so-called omnibus claim. The court therefore, only had to consider claim 1 of the patent. If claim 1 of the patent is not infringed, none of the remaining claims will be infringed.

In the judgment, claim 1 was divided into the following integers:

(a)  A preload device for an elongated load support including;

(b)  a pressure vessel;

(c)  a recess in the form of a socket having a cylindrical side wall in one wall of the vessel in which an end of a support may be located;

(d)  an outer wall which is radially spaced from the cylindrical wall of the socket with the outer end of the socket wall being convexly curved in cross-section on the outer wall of the vessel;

(e)  to define at least a portion of a chamber in the vessel which surrounds the socket;

(f)   and means for inflating the vessel to shallow the socket.

Having regard to the above essential integers, Videx contended that their product did not include integers (d) and (f). The court a quo agreed and accordingly issued a declaration of non-infringement.

In the Supreme Court of Appeal, the court again considered integers (d) and (f). The court stated that the Videx product did not include the feature of integer (d) of claim 1 as “the annular rim of the recess component of the Videx pot is not convexly curved in cross-section onto the outer wall but is flat over a substantial part of its radial extent“. As to integer (f), the court stated that “the purpose of the inflating mechanism of the Videx pot is...not to shallow the socket as occurs in the patented device”. The court also quoted the court a quo with approval in that the Videx product operates according to a different principle than that required in the patent specification.

The appeal was dismissed with costs.