EnsignBickford (SA) (Pty) Ltd and others v AECI Explosives and Chemicals Ltd
 4 All SA 453 (A)
Supreme Court of Appeal
21 September 1998
Van Heerden DCJ, Harms, Schutz, Scott and Plewman JJA
JJF Hefer and I Potgieter
1999 (1) SA 70 (SCA)
. Editor's Summary . Cases Referred to . Judgment .
Patent Infringement Onus of proof Allegation of infringement Onus is on the party alleging same Party alleging
invalidity of patent bears onus of proving same.
Patent Infringement Grounds of invalidity (i) Novelty, (ii) Obviousness, (iii) Ambiguity.
Patent Novelty Specification "Narrow construction" of specification Would offend against a fundamental principle of
patent law, ie that the claim must be read as part of the entire document and not as separate document.
The Respondent (Plaintiff in the court a quo) brought two actions against the Appellants (Defendants in the court a
quo) for the alleged infringement of a patent in respect of an invention relating to plastic tubes. The court a quo
found in favour of the Respondent. The instant case is an appeal against this decision.
Held The onus of proof on the issue of infringement of patent fell to the Respondent and on the issue of invalidity
the onus fell to the Appellants.
The Appellants had raised three grounds of invalidity viz.: (i) novelty the patent was not patentable in terms of
section 25 of the Act as it was not new; (ii) obviousness the patent did not involve an inventive step, and (iii)
ambiguity the claims made by the Respondent were not clear in terms of section 61(1)(f )(i) of the Patents Act 57
of 1978. The issue of ambiguity was not persued and the Court disregarded same.
(i) Novelty: The Court's first inquiry was what the nature of the invention was. In terms of the Plaintiff's claim the
invention was a (i) lowenergy fuse consisting of a plastic tube, the inner surface of which was coated with
explosive in powder form, (ii) a particular characteristic was that the plastic tube was of sandwichtype construction
comprising of two parts, (iii) an outer part endowing the plastic tube with resistance to external damage, and (iv)
an inner part, the inner surface of which had adhessive properties which would only allow the explosive agent to
become dislodged substantially by a shock wave.
The Respondent's claim appeared to have a wide ambit in the sense that it was left to a person skilled in the art
to select, according to his skills and wishes, the grade or type of plastic tube or tubes which were to make up the
"sandwichtype" plastic tube. The Appellant's submission was that the claim had to be construed in the more
narrow sense as being limited to certain powder loadings mentioned in the specification of the patent. The Court
held that there was nothing contained in the body of the specification to provide a dictionary for the claims or even
to affect the wording of the claims. To construe the claims in the wide sense as proposed by the Plaintiff would
offend against a fundamental principle of patent law, viz.: that the claims must be read as part of the entire
document and not as a separate document.
Page 454 of  4 All SA 453 (A)
(ii) Obviousness: With respect to the issue of obviousness the Court held that an objection based on a lack of
inventiveness is one of long standing in our patent law. It was found in both the 1916 and 1952 Patents Acts. In
terms of section 23(1)(d) of the 1952 Act, it was a ground for revocation of a patent that the invention was "obvious
in that it involves no inventive step having regard to what was common knowledge in the art at the effective date".
Lack of inventiveness is a ground for revocation under the present Act by reason of the provisions of section
25(1), (6) a n d (10) read with section 61(c). These provisions constitute a statutory code. In effect all available
knowledge is the starting point and lack of inventiveness only arises as an issue if the invention has survived the
attack on novelty.
In order to apply these provisions to a particular case the Court found it appropriate to adopt tests formulated in
certain English authorities viz.:(i) What is the inventive step said to be involved in the patent in suit?; (ii) What was,
at the priority date, the state of the art (as statutorily defined) relevant to that step?; (iii) In what respect does the
step go beyond, or differ from, that state of the art? and (iv) Having regard to such development or difference,
would the taking of the step be obvious to the skilled man?
The issue therefore was whether what is claimed as inventive would have been obvious not whether it would
have been commercially worthwhile and further the emphasis must lie on the technical features.
With respect to the issue of inventiveness the Court also considered whether there was any secondary evidence