“When a witness, particularly one testifying in support of obviousness, uses words such as ‘imaginative’ and ‘creative’, it tends instead to support a conclusion of inventiveness and hence patentability.”

South Africa’s Supreme Court of Appeal was confronted with an interesting case in Mantella Trading 310 v Kusile Mining, where the disputed issues, outside of the expected ones of patentability and infringement, concerned sufficiency.

The respondent, Kusile, had convinced the lower court that the patent, directed to ventilation systems for mining operations, was liable to revocation on the basis of lack of inventive step. The appeal court agreed.

Kusile raised the following grounds in support of its claim for revocation (brought in reaction to a claim for infringement):

• The claims of the patent were not based on matter disclosed in the patent specification;
• The claims were otherwise unclear; and
• The patent failed to sufficiently describe, ascertain and where necessary illustrate and exemplify the invention and the manner in which it is to be performed, thereby permitting the skilled addressee to perform the invention.

Many of the arguments (including that of inventive step) revolved around the words “rigid material” as used in the specification.

In relation to the grounds for insufficiency, without any specification-based dictionary for the term and also without any special meaning derivable from the industry, the Supreme Court concluded that the phrase must be given its ordinary grammatical meaning.

Three expert witnesses offered testimony. This was done in order to construe the claims purposively, meaning they must not be read in isolation but in the context of the whole of the specification. A court’s understanding of the specification through an expert’s eyes would also answer the ground of lack of clarity.

Meanings that are consistent with that of the overall specification are meanings to be accepted as demonstrative of the intention of the author (and through it the patentee) at the time of drafting. A dictionary having several meanings of a word provides a guide to its interpretation, bearing in mind its context in the specification.

The court described who the skilled addressee is. In summary he or she is someone who is expected to bring reasonable intelligence to bear on the language of the specification, and who, while not required to struggle unduly with it, is to make the best of it and not adopt an attitude of studied obtuseness.

On the basis of expert testimony, the court ruled against the sufficiency arguments.

Infringement was common cause, as the court took account of the fact that the infringing articles bore similar material to the patent claims. Having copied the very feature that was characterised as being insufficient (or insufficiently worded) in the writer’s view probably assisted the court in holding against the sufficiency argument.

Turning now to deal with lack of inventive step, the court noted that the invention was a simple one that brought together known elements in achieving its result. The court held that its very simplicity contributed to its invalidity, and although it cautioned itself against a hindsight argument of invalidity, upheld revocation.

Even though different methods were employed between the cited prior art and the invention subject to present scrutiny, these methods achieved the same effect, which the court saw as a ground confirming revocation. While this appears at face value to be a decision against the existence of the doctrine of equivalents, no explicit argument was raised in this regard.

In dealing with the question of obviousness, the court relied on the well-known test of obviousness, which essentially is represented by four questions, namely to identify the inventive step, to define the state of the art, to identify the differences between the invention and the state of the art, and to quantify such difference with regards to obviousness.

When a witness, particularly one testifying in support of obviousness, uses words such as “imaginative” and “creative”, it tends instead to support a conclusion of inventiveness and hence patentability, irrespective of simplicity. What further assisted the court to maintain its position in favour of inventive step was that the patented article fulfilled a long established need in the field and enjoyed commercial success.

The judgment is a sound one and its reasoning represents a comprehensive list of questions one would have to answer, whether as patentee or applicant, for revocation. It is therefore a recommended read for future or current patent litigants in the South African context.

Publication Name: The importance of semantics

Date: July, 2015