(g) provided by a continuous edge trimmed weld and
(h) spacer elements
(i) secured to the filter medium in the air flow direction,
(j) and, if desired, by additional welded stiffening zones,
(k) and that the edges approached by the air flow are continuously and undetachably connected with the
supporting frame
(l) which is made of a hard foamed material
(m) and is connected directly with the filtering medium by a foaming process.
Claim 5 was in respect of a gas filter element, substantially as described in an accompanying drawing.
The Respondents ("the patentee") alleged that the Appellant had infringed claims 1 and 5 of the specification of
the patent. The Appellant admitted that it had copied the commercial product made and sold by the patentee but
denied infringement of the patent. In addition, the Appellant counterclaimed for revocation of the patent on several
grounds of alleged invalidity of claim 1.
The court a quo granted judgment in favour of the patentee on 12 March 1996 and leave was granted to appeal
to the Supreme Court of Appeal.
The patent lapsed on 16 September 1996.
Held The Court noted that the validity of the patent was to be decided in terms of the repealed Patents Act 37 of
1952 ("the Act").
Infringement: The Appellant had admitted that it had copied the patentee's commercial product and the Court
found on the facts that the Appellant had infringed claims 1 and 5.
Invalidity: The Court considered each of the Appellant's allegations regarding the invalidity of claim 1 of the
specification of the patent; these were: ambiguity, inutility, anticipation or lack of novelty and obviousness or lack of
subjectmatter. Although it was trite that each objection had to be considered in isolation, the evidence led on one
aspect was not necessarily irrelevant to another.
Ambiguity: With regard to the meaning of the word "selfsupporting" in integer (f) of claim 1, the Court found that
no inconsistencies existed between
Page 241 of [1998] 1 All SA 239 (A)
the wording of the specification and the ordinary English meaning of the word. The Court confirmed the finding of
the court a quo that the use of the phrase "if desired" in integer (j) did not have the effect that the claim was
rendered uncertain or unclear; the formulation used merely reduced integer (j) to an inessential integer.
Inutility: An invention was not useful if it did not effectively produce the result aimed at or promised by the
specification. In casu, the specification promised that a filter made according to the claims would attain the
performance of rigid high surface filters and avoid the disadvantages of the prior art filters. The Court found that the
Appellant's evidence and argument in this regard was based upon a misconception of the promise of the invention.
The attack on the utility of the patent accordingly failed.
Lack of novelty (s1(ix)(d)): With regard to the Appellant's allegation of the existence of a document describing
the invention, the Court held that the Appellant had to prove that at the effective date: (a) the document was
published; (b) there was a copy of it in the Republic of South Africa; and (c) the document described the invention.
The Court found that the third requirement was not fulfilled and it was therefore not necessary to decide the first
two issues. In order for a document to describe the invention, it had to set forth or recite at least its essential
integers in such a way that the same or substantially the same process is identifiable or perceptible and hence
made known from that description, or the same or substantially the same thing could be made from the description.
Anticipation (s1(ix)(a)): The Court then considered the Appellant's argument that the invention was not "new" as
defined in the Act. In the light of the evidence before it, the Court could not conclude that the filters known or sold
in South Africa before the effective date fell within the scope of the patent.
Obviousness: The Court found on the evidence that the invention was not obvious nor had the Appellant shown
that the invention was obvious to the ordinary worker in the art. The Appellant had not shown that the trial judge
had erred in his assessment on this point.
Costs of the interim interdict: The Court held that there was nothing to show that the trial judge did not have
due regard to the parties' arguments in respect of the costs of the interim interdict. The court a quo was in a more
favourable position to make a decision with regard to such costs and the Court was not in a position to reconsider
the exercise of the trial court's discretion.
The appeal was accordingly dismissed with costs including the costs of employing two counsel.
Notes
For Appeals, see LAWSA Reissue, (Vol 5(2), paragraph 107)
For Costs, see LAWSA Reissue, (Vol 3(2), paragraphs 1288)