purchased from Brandt, the patentee's local agent, "Viledon G35 Coarse" and "Viledon F45 Fine" filters. As
mentioned, document "BB" dated August 1975 was sent to Ubsdell without any restrictions two days before the
effective date of the patent.
Page 251 of [1998] 1 All SA 239 (A)
View Parallel Citation
On 3 September 1975, the patentee informed its agents that it had a new pocket for the market, namely a Viledon
Compact "Grob 8", a "new version with 8 pockets". The existing pockets were to be marketed as Viledon Compact
"Grob 4" and "Fein". The first reference to these three names in trade literature is found in a technical brochure of
Brandt dated March 1976 which, according to a note found, replaced "BB". The filters shown in this brochure do not,
on the face of it, have any rods. The technical data concerning "Grob 4" differ in some respects from that contained
in the product it was supposed to replace, namely the one in "BB". Technical differences between the "Fein"
disclosed at the meeting of 18 March 1975 and the "Fine" of the March 1976 document are apparent. There is no
indication at all when the filters offered in the circular of 3 September 1975 reached the market, whether in South
Africa or elsewhere. What is relevant, is that all the sales relied upon by the appellant as proof of prior knowledge
or use in South Africa predate this circular. On what is on record, these filters had to be those described in the
minutes of 18 March 1975, one of which was depicted on "BB". Nothing further is known of the "Fein".
To prove that the Viledon pocket filters brought to South Africa before the effective date were made according to
the invention, the appellant relied heavily on what was submitted to be common cause, namely that (quoting from
the heads of argument) the "compact filters of 1975 were identical to those of today and that they had all the
integers of the claims" and that "it was admitted by the respondents that the first respondent has only ever sold
one type of Viledon compact filter, ie that made in accordance with the patent".
Temporary interdict proceedings preceded the trial, and in a replying affidavit a deponent the head of the
patentee's patent department who did not testify at the trial, although present, admitted that "the configuration
as well as the production method of today's VILEDON COMPACT FILTERS is essentially identical to those of 1975.
There were only some minor changes in the quality of the materials and fibres utilised." He added that the Viledon
bag filters were selfsupporting and that filters were produced fitted with a crossrod to provide additional support
for the filter pockets. The date given, namely 1975 is, in the light of what I have said, somewhat ambiguous and
confusing. Reliance was also placed upon the evidence of Mr Schorn, who, at the time was employed by Brandt.
According to his testimony, the patentee, to his knowledge, never made any Viledon compact filters save according
to the invention. There is nothing to show that he knew the contents of the specification, either in 1975 or even at
the time of the trial. Finally, Bubenzer, the manager of Brandt at the time, when asked whether the patentee had
ever sold any pocket filter other than the pocket filters exemplified by the exhibits before the court, said "no".
Many exhibits were before the court; some of them did not fall within the scope of the patent. For instance, there
was another version of the Viledon G35/K (which first appeared on "BB") without a rod, spacers or welds for the
spacers and with five pockets. There were Viledon M 85 and M 95 pocket filters that collapse if their holding wires
are removed. These Viledon pocket filters that fall outside the scope of the patent were
View Parallel Citation
introduced by Mr Franklin to prove the lack of utility. Another Viledon filter not covered by the patent is the one
exemplified on "BB". Mr Franklin thus clearly and effectively established that the "admissions" he wishes to rely
upon were wrongly made. His submission that the matter was common cause, overstates the position, because it
was the
Page 252 of [1998] 1 All SA 239 (A)
appellant's main case that neither the ordinary Viledon filter, nor the appellant's copy, falls within the scope of the
claims because the selfsupporting properties derive from the filter material and not the welds and spacers.
Moldow did not take the matter much further. He knew the product depicted in "BB" and although he said that it
was an early model (which it was), he did not say (as Mr Franklin put it to Schorn and during argument) that the
product was merely a prototype. Ubsdell's evidence proves no more than that he purchased Viledon pocket filters
and requested and received "BB". He did not say that the filters received were identical to or different from that
portrayed on "BB". In an attempt to remedy this defect in his evidence, Mr Franklin sought to rely on Ubsdell's
affidavit filed by the appellant in the interim interdict proceedings in which he expressed the opinion that the filters
he had dealt with during 1975 had all the integers of claim 1. He did not describe or illustrate the filters, he gave no
reasons for his opinion, he was not called as an expert, and he did not confirm his opinion in court. The belated
recourse to section 34(1) of the Civil Proceedings Evidence Act 25 of 1965 must fail. No intimation was given at the
trial that reliance would be placed upon the contents of the affidavit in addition to the oral evidence. Nor was any
reason proffered why Ubsdell could not have given the evidence in court. In short, "there was no factual reason or
need for the appellant to invoke sec. 34 at all" (Narlis v South African Bank of Athens 1976 (2) SA 573 (A) 578AB).
Only the evidence concerning the prior use at or by H Lewinberg (Pty) Ltd deals in any way with the question
whether the filters that were sold before the effective date fell within the scope of the claims. MacArthur J found the
evidence on the issue "unconvincing and somewhat contrived" and I am not satisfied that his assessment is wrong.
On the assumption that he was too critical, I do not think that one can rely, without a smattering of corroboration,
on the statement of Mr Mostert that the filter he saw during January 1976 had no rods or wires. Even if one could,