THE SUPREME COURT OF APPEAL OF SOUTH AFRICA
JUDGMENT

Case No: 20453/2014
Reportable

In the matter between:
STRIX LIMITED

APPELLANT

and

NU-WORLD INDUSTRIES (PTY) LTD

RESPONDENT

Neutral Citation:
Strix Limited v Nu-World Industries (20453/2014) [2015] ZASCA
126 (22 September 2015).
Coram:
Navsa, Saldulker, Swain and Dambuza JJA and Van der Merwe
AJA
Heard:

17 August 2015
Delivered:

22 September 2015
Summary:

Patent – alleged infringement of patent relating to overheat control
in kettle comprised of multiple sensors spaced apart – interpretation of patent –
allegedly infringing kettles falling within scope of claims – defence of invalidity of patent

– lack of novelty alleged – defence available even where revocation of patent not
sought – allegedly infringing kettles not embodied in prior publication - obviousness
expressly abandoned in court a quo, but raised on appeal – would be prejudicial to
appellant to allow at this late stage – held that patent had been infringed.

______________________________________________________________________

ORDER
______________________________________________________________________

On appeal from: Court of the Commissioner of Patents (Preller J sitting as court of first
instance).

The following order is made:

1.
The appeal is upheld with costs including the costs of two counsel.
2.
The order in the court below is set aside and the following is substituted:
„(a)
the defendant is interdicted from infringing claim 1 of South African Patent
95/4779 (“the patent”) by making, using, disposing, offering to dispose of, or
importing liquid heating vessels containing Liang Ji LJ-06A, Liang Ji LJ-06 or
Sunlight SLD-105A IL thermally sensitive overheat controls or any other
thermally sensitive overheat controls as claimed in claim 1 of the patent;
(b)
the defendant is ordered to deliver up any product infringing the patent and any
article or product of which an infringing product forms an inseparable part;
(c)
as to damages:
(i)
an enquiry is ordered as to the damages suffered by the plaintiff as a
result of the infringement of the patent by the defendant, alternatively as
to the amount of a reasonable royalty as contemplated in s 65(6) of the
Patents Act, 1978 and payment of the amount found to be due to it;
(ii)
in the event of the parties being unable to reach agreement as to the
further pleadings to be filed, discovery, inspection or other matters of

procedure relating to the enquiry, any of the parties may make application
to the court for directions in regard thereto;
(d)
the defendant is ordered to pay the plaintiff‟s costs, including the costs of two
counsel to the extent that such were employed and including the qualifying and
attendance fees of the expert witness Richard Moorhouse.‟
______________________________________________________________________

JUDGMENT
______________________________________________________________________
Navsa JA (Saldulker, Swain and Dambuza JJA and Van der Merwe AJA concurring):

[1] This appeal is directed against a finding by the Court of the Commissioner of
Patents (Preller J), that claim 1 of the patent in suit was not novel1 and that in any event
the import and sale of kettles by the respondent, Nu-World Industries (Pty) Ltd, did not
infringe appellant‟s patent 95/4779. I shall, for convenience, refer to the appellant and
respondent as Strix and Nu-World, respectively.

[2] The patent is entitled „Liquid heating vessel‟. Claim 1 which is central to the
dispute reads as follows:
„1. A liquid heating vessel comprising: a liquid receiving container; an electrical heating
element provided on or in thermal contact with the base of said container; a thermally sensitive
overheat control arranged to operate in the event of said element overheating so as to interrupt
or reduce the supply of electrical energy to the element; said thermally sensitive overheat
control comprising at least two thermally responsive sensors arranged in good thermal contact
with, and at spaced apart locations on, the base of the container or the element, said sensors
individually being operable, in the event only of said element overheating when the vessel boils
dry or is switched on dry so as to interrupt or reduce the supply of electrical energy to the
element.‟

[3] The following are the agreed 8 integers in respect of claim 1:

1 Although, as will become apparent later, the court below appears to have confused novelty and
obviousness.

„(a)
a liquid heating vessel comprising:
(b)
a liquid receiving container;
(c)
an electrical heating element provided on or in thermal contact with the base of said
container;
(d)
a thermally sensitive overheat control arranged to operate in the event of said element
overheating so as to interrupt or reduce the supply of electrical energy to the element;
(e)
said thermally sensitive overheat control comprising at least two thermally responsive
sensors;
(f)
arranged in good thermal contact with;
(g)
and at spaced apart locations on, the base of the container or the element;
(h)
said sensors individually being operable, in the event only of said element overheating
when the vessel boils dry or is switched on dry so as to interrupt or reduce the supply of
electrical energy to the element.‟

[4] At the priority date in 1994, thermally sensitive kettle controls were not novel. It is
undisputed that integers (a)-(d) were part of the prior art. Integers (e) to (g) are critical in
the determination of the present dispute. At the priority date of the patent in suit it was
common to have electrical kettles with a thermally sensitive overheat protection switch
in thermal contact with the heating element of the kettle which, when activated, would
interrupt the supply of electrical energy to the element. That would happen for example
when the vessel boiled dry or if it was switched on without any liquid in the vessel. A
thermally sensitive switch in the base of the kettle was also in use at the priority date of
the patent in suit. The actuator switch could either reset automatically upon the vessel
cooling down or it might have consisted of a once-off switch which had to be replaced
after serving its purpose, namely, turning off the electrical supply. In this judgment, for
practical purposes, we use the words „sensor‟ and „control‟ interchangeably.

[5] The relevant part of the patent specification of the patent in suit states that the
problem with existing switch controls of the type located in the base of the kettle as
described above is that the temperature of the container base of the kettle is sensed at
a single location. In the body of the patent specification an example is provided of how,
because of a single thermally sensitive switch, problems could arise, namely:

„The problem with existing controls of this type is that the temperature of the container
base, and thus indirectly the temperature of the element, is sensed effectively only at a single
location on the base. Thus if, for example, the vessel is accidentally placed on a work surface
so that its base slopes, it is possible that as the vessel boils dry one part of the bottom of the
container may still be covered by water, but another be uncovered. This part of the base will
therefore overheat first, and if the overheat protecting means is arranged under the part of the
vessel base still covered with water, severe overheating of the element may occur locally which
is potentially very dangerous.‟

[6] The body of the patent specification goes on to state the following:
„The invention from one aspect seeks to provide an improved vessel of the above type.
From a first aspect therefore, the invention provides a liquid heating vessel comprising: a liquid
receiving container; an electrical heating element provided on or in thermal contact with the
base of said container, a thermally sensitive overheat control arranged to operate in the event of
said element overheating so as to interrupt or reduce the supply of electrical energy to the
element, said thermally sensitive overheat control comprising at least two thermally responsive
sensors arranged in good thermal contact with, and at spaced apart locations on, the base of
the container or the element, said sensors individually being operable, in the event of said
element overheating so as to interrupt or reduce the supply of electrical energy to the element.
Thus in accordance with the invention, at least two thermally responsive sensors are provided in
close thermal contact with the base of the vessel container, which will allow the temperature of
the base and element to be detected accurately at at least two spaced apart locations so that
should the base or element overheat locally, at least one of the sensors may sense this quickly
and operate to interrupt or reduce the power supply to the element, for example opening a set of
electrical contacts remote from the sensor through suitable actuating means.‟ (My emphasis.)

[7] Simply put, if regard is had to claim 1 and the constituent integers set out above,
and indeed to Strix‟s contentions in the court below and before us, the novelty claimed
is that there are two thermally sensitive switches, spaced apart, on the base of the
kettle, which provide an additional safety measure against overheating. The body of the
patent specification states that the additional switch is a measure against the danger of
overheating that could be caused by the kettle‟s base being placed unevenly (at a
slope) and the one switch not sensing that a part of the base is uncovered by water

which is potentially hazardous. In short, it was submitted on behalf of Strix that the
patent related to an improved kettle with a novel feature of spaced apart sensors
serving the aforesaid purpose.

[8] Nu-World, a South African company, makes, imports and sells, amongst others,
electrical kettles. The litigation leading up to the present appeal commenced with Strix,
a company registered in the Isle of Man, instituting an action against Nu-World in the
court below seeking an order in the following terms:
„(a)
an interdict restraining the defendant from infringing claim 1 of South African
patent 95/4779 by making, using, disposing, offering to dispose of, or importing liquid heating
vessels containing Liang Ji LJ-06A, Liang Ji LJ-06, Sunlight SLD-105A IL or Jia Tai KSD688-A
thermally sensitive overheat controls;
(b)
an order for the delivery up of any product infringing South African patent 95/4779 and
any article or product of which an infringing product forms an inseparable part;
(c)
as to damages
(i)
an enquiry as to the damages suffered by the plaintiff as a result of the
infringement of the South African patent 95/4779 by the defendant, alternatively
as to the amount of a reasonable royalty as contemplated in s 65(6) of the
Patents Act, 1978 and payment of the amount found to be due to it;
(ii)
an order directing that, in the event of an enquiry in terms of sub-paragraph (i)
being ordered and the parties being unable to reach agreement as to the further
pleadings to be filed, discovery, inspection or other matters of procedure relating
to the enquiry, any of the parties may make application to the court for directions
in regard thereto; and
(d)
costs of suit.‟

[9] By agreement between the parties, merits and quantum were separated and the
trial proceeded to determine whether Strix was entitled to interdictory relief. It was
agreed that each of the kettles listed in the preceding paragraph had two thermally
sensitive overheat controls. The question was whether a Nu-World kettle with any one
of these controls constituted an infringement of claim 1 of the patent in suit. After
hearing the evidence, including those of experts, Preller J reasoned and concluded as
set out immediately hereafter. First, the learned judge rightly took into account that he

was addressing novelty and therefore considered prior art. He held that at the priority
date the idea of two thermally sensitive switches in an electrical kettle was well known.
In this regard Preller J took into account Strix‟s own prior patent registered in the United
Kingdom during 1985 on which Nu-World relied. He went on to find that at the priority
date the idea of more than one overheat control in kettles was not novel. He concluded
that everything contained in integers (e), (f) and (h) was part of the prior art. Turning to
integer (g) Preller J held that it did not necessarily form part of the prior art. Having
regard to that integer and the patent specification he took the view that, to serve the
stated purpose of providing a safety feature in the event of the kettle being tilted, the
two thermally responsive sensors must be at substantially spaced apart locations on the
base of the kettle. He went on to say:
„It is difficult to imagine such a person not immediately saying that to provide for such an
eventuality the two overheat controls must be mounted as far apart as possible. It is an obvious
solution for the problem and requires hardly any ingenuity. It follows then that the invention did
not add anything new to the prior state of the art and that the defendant‟s defence on this basis
must be upheld.‟
From the above, and as will be explained in due course, it appears that the learned
judge did not keep the distinction between lack of novelty (ie anticipation) and
obviousness in mind.2 He went on to find that the thermally sensitive controls in each of
the allegedly offending kettles were too close together to serve the stated purpose and
thus concluded that there was no infringement of the patent in suit. Consequently, the
court below dismissed Strix‟s claim with costs. It is against that order and the
aforementioned conclusions that the present appeal is directed.

[10] Before us Strix contended, firstly, that in the absence of a claim in reconvention
by Nu-World for revocation of the patent, a defence that the patent in suit was not novel
at the priority date was unavailable to the latter. Furthermore, so it was contended on
behalf of Strix, the defence was, in any event, not specifically pleaded and could thus
not be relied upon. It is common cause that there was no counterclaim for the
revocation of the patent based on its invalidity for lack of novelty. Nu-World is adamant

2 In this regard see T D Burrel Burrel’s South African Patent and Design Law 3ed (1999) para 4.12.2 at
169-170 and the authorities there cited.

that this defence was nevertheless pertinently raised. In this regard Nu-World points out
that in response to Strix‟s claim that the patent was at all relevant times valid and in full
force and effect and was being infringed by Nu-World, the plea denied the validity and
enforceability of the patent in suit as well as any infringement. According to Nu-World
the defence was specifically predicated and raised in its summary of expert opinion,
with reference to prior art. Moreover, so Nu-World asserted, it was made clear in the
opening address by counsel on its behalf and referred to and dealt with extensively in
the viva voce evidence and in argument at the conclusion of the case.

[11] Secondly, it was submitted on behalf of Strix that even if the defence of invalidity
was available to Nu-World, the latter had not shown that the allegedly infringing kettles
were simply embodiments of kettles described in a publication prior to the patent in suit.
Lastly, Strix submitted that the court below erred in its restrictive interpretation of the
words „at spaced apart locations‟ as contained in integer (g), and the consequent finding
that the overheat controls were not arranged in such a manner.

[12] At the outset it is necessary to consider whether, in the absence of a claim for
revocation of the patent in suit the defence of invalidity on the basis of lack of novelty
was available to Nu-World. Section 65(4) of the Patents Act 57 of 1978 (the Act)
provides:
„In any proceedings for infringement the defendant may counterclaim for the revocation
of the patent and, by way of defence, rely upon any ground on which the patent may be
revoked‟
Section 61 sets out the grounds of revocation of patents, including that the invention is
not patentable in terms of section 25 (s 61(1)(c)).
Section 25 bears the title „Patentable inventions‟, and section 25(5) reads as follows:
„An invention shall be deemed to be new if it does not form part of the state of the art
immediately before the priority date of any claim to that invention.‟
The relevant part of section 25(10) reads as follows:
„. . . [A]n invention shall be deemed to involve an inventive step if it is not obvious to a person
skilled in the art, having regard to any matter which forms, immediately before the priority date
of the invention, part of the state of the art . . . .‟

[13] A defence based on the invalidity of a patent on the statutorily recognised ground
of lack of novelty is competent without a claim for revocation. That appears to be clear
from the wording of s 65(4) read with the other sections of the Act referred to above. In
Clipsal Australia (Pty) Ltd & another v Trust Electrical Wholesalers & another [2007]
ZASCA 24; 2009 (3) (SA) 292 (SCA) at 295B-C para 15, Harms ADP, in dealing with
almost identical wording contained in corresponding sections of the Designs Act 195 of
1993, said the following:
„The defendant in infringement proceedings may counterclaim for the revocation of the design
registration or, by way of defence, rely on any ground on which the registration may be revoked
(s 35(5)). In this case, the respondents chose the second option, namely to rely by way of
defence on the grounds that the design was neither new nor original as required by s 14(1)(a),
which are grounds for revocation under section 31(1)(c). In addition they denied infringement,
alleging that their products do not embody either of the two designs and differ substantially from
them.‟
The consequence of not applying for revocation was spelt out In Thomas Grant v
Winkelhaak Mines Limited 1985 BP 143 (CP) at 152 where Nestadt J said the following:
„As Mr Osborn pointed out, although the Patents Act allows for invalidity to be raised as a
defence, it does not require that a counterclaim for revocation be coupled therewith (Section
65(4) of Act 57 of 1978). If invalidity is raised only by way of a defence it has no consequence
beyond the parties to the action. Even if a defence of invalidity is successful, thereby defeating
an infringement action, the patent remains on the register and the proprietor can sue others on
the patent.‟
See also Roman Roller CC & another v Speedmark Holdings (Pty) Ltd [1995] ZASCA
78; 1996 (1) SA 405 (A), at 412H-J and Electro-Medical Corporation (Pty) Ltd v
Madame et Monsieur Franchise (Pty) Ltd & others 1996 BP 539 (CP), at 543B-544C.
This disposes of the first point raised on behalf of Strix as recorded at the beginning of
para 10 above.

[14] The next question then, is whether, in the present case the defence of invalidity
on the basis of lack of novelty of the patent was indeed pleaded and whether novelty
was indeed an issue in the trial. At the outset it needs to be acknowledged that Nu-

World‟s defence to Strix‟s particulars of claim was pleaded in general and vague terms
and for reasons that will become apparent, perhaps designedly so. Nu-World‟s plea is a
general denial of the plaintiff‟s claim that the patent in suit is valid and enforceable and
that there was in fact an infringement. However, in a supplementary expert notice in
terms of Uniform Rule 36(9)(b) there is an express and relatively detailed reference by
Nu-World to prior art and the lack of novelty of the patent in suit is pertinently raised.
Novelty as an issue was also distinctly raised by counsel on behalf of Nu-World during
his opening address and the trial was conducted on the basis that it was an important
issue in the case. That disposes of the second submission on behalf of Strix.

[15] That leads us to the next question, namely, whether the patent was invalid on the
basis of lack of novelty. In this regard, it is necessary to be reminded that the onus of
proving that the patent in suit was invalid rested on Nu-World.3 The prior art relied on by
Nu-World is that embodied in Strix‟s own expired 1985 United Kingdom patent (GB
2181 598 A). The 1985 patent relates to thermally sensitive controls for electric heaters
for containers such as kettles. The body of the patent specification records that
thermally sensitive controls for heaters, which include a switch meant to interrupt power
supply in the event of overheating, are well-known. It further indicates that the heaters
to which the patent relates are either immersion heaters or „similarly constructed
heaters mounted externally to the containers in good thermal contact with a wall thereof,
for example being brazed to the underside of the container base‟. The 1985 patent then
goes on to describe the use of such controls principally in immersion heaters. The
problem sought to be overcome, so that patent specification asserted, was that in the
event of failure of the one switch the power supply would not be interrupted leading to a
potentially hazardous situation. That patent sought to introduce an effective back-up
protection in the form of a second improved thermally sensitive switch as a further
safety measure in the event of the failure of the first. The features described in this and
the preceding paragraph would encompass integers (a) to (e) of the patent in suit.

3 See Gentiruco AG v Firestone SA (Pty) Ltd 1972 (1) SA 589 (A) at 629D-F.

[16] The patent in suit acknowledged prior art which encompassed integers (a) to (d).
It is clear that integers (e) to (h) are claimed in combination. The problem for Nu-World
is that the 1985 patent does not describe two thermally responsive sensors arranged in
good thermal contact with the base of the container. Although the 1985 patent describes
two thermally responsive sensors, one being a bimetallic actuator or sensor (item 11 on
Figure 1 of the 1985 patent) and the other a push-rod or thermal fuse (item 27), neither
of these sensors are in good thermal contact with the base of the container and it is only
the bimetallic sensor that is in good thermal contact with the element (item 5). The
bimetallic sensor is located adjacent to where the „hot return‟ of the element is brazed to
the heater (element) head but the thermal fuse is placed a distance apart from the „hot
return‟ and is in poor thermal contact with the element. lntegers (e) and (f) in
combination are not embodied in the 1985 patent. Indeed, integer (f) is conspicuously
absent. Furthermore, and critically, the 1985 patent does not describe two thermally
responsive sensors spaced apart on the base of the container. Thus, critically, integer
(g) also does not form part of the prior art. The problem that the patent in suit sought to
address would occur when one part of the kettle base is uncovered with water and
would overheat at that spot whilst another part of the base would be covered. The effect
of the second control would be that the control at the part that overheats because it is
dry would activate and cut off the electricity supply. The 1985 patent dealt in the main
with immersion heaters, in which an element to which the thermally sensitive controls
were linked would protrude into the container vessel from a side wall of the kettle
container, and perhaps extend to its base. The juxtaposition of the two controls in order
to deal with the safety problem that might ensue in the event of the kettle being tilted
was not considered or addressed. Simply put, the additional safety feature in the form of
two thermally sensitive controls spaced apart and in good thermal contact with the base
to deal with the problem that might present itself, when the kettle is tilted, does not
occur in the prior art.

[17] It thus appears to me to be clear that the combination of integers (e) to (g) were
not embodied in prior art and constituted a novel safety feature as described above.

[18] It is true, as noted by the court below, that the patent specification provided as
follows:
„. . . to obtain a good response, the sensors should be spaced apart by a substantial distance.‟
(My emphasis.)
And further, later in the specification:
„As stated above, preferably only two actuators are provided, most preferably spaced apart by
substantially 180°.‟
„Substantial‟ is defined in the Shorter Oxford Dictionary, amongst others, as follows:
„5. Of an act, measure, etc.: having force or effect, effective, thorough.‟
The adjective is relative to subject matter. In this particular instance distances have to
be considered in relation to the relatively limited extent of the base of the kettle. It also
has to be borne in mind that the controls being spaced apart has the purpose described
above, namely, to provide a safety measure in the event of the kettle being tilted. In
short, as will be demonstrated below, an 8 millimetre distance between the controls was
„significant‟ enough for the controls to be effective.

[19] I now turn to deal with Preller J‟s conclusion that there was no infringement of the
patent in suit because the controls in the allegedly offending kettles were too close
together to be effective as a safety feature. In coming to the aforesaid conclusion, he
disregarded the tests conducted on the kettles in question by Nu-World‟s own witness,
Mr Mark Wheeler, who completed a report setting out the nature and the results of the
tests which he had conducted on the kettles in question. The report was compiled to
demonstrate that the controls in each of the kettles, which were the subject of the
litigation, were substantially ineffective to serve the purpose spelt out in the patent
specification, namely, to act as a safety feature in the event of the kettle being tilted.
Ironically, the test results proved the controls to be relatively effective.

[20] In three of the kettles, namely Sunlight SLD-105A IL, Liang Ji LJ-06 and Liang Ji
LJ-06A the distances between the sensors were 8 millimetres, 8 millimetres and 12
millimetres respectively. In Jia Tai KSD688-A there was a bridge between the sensors
and the distance was zero millimetres.

[21] Mr Wheeler‟s evidence during the trial that the further apart the sensors the more
effective they would be to serve the purpose referred to in the specification and in the
preceding paragraph is undoubtedly correct. His evidence that a Strix kettle with a 37
millimetre distance between the sensors was effective to serve the purpose is also
uncontested. Despite Mr Wheeler‟s report stating that the controls in the Nu-World
kettles were ineffective, and despite his protestations when he was testifying that this
was indeed so he conceded, with reference to the tests he conducted, that a Nu-World
kettle with an 8 millimetre distance between the sensors, when filled with 120 millilitres
of water would have one of the sensors activated when the kettle was tilted at 19
degrees. The totality of tests conducted and reported on by Mr Wheeler show that in the
Nu-World kettles with an 8 millimetre distance between the sensors one would be
activated when filled with volumes of water varying from 40 to 120 millilitres, when tilted
at angles ranging from two to 19 degrees. The Nu-World kettle with sensors spaced 12
millimetres apart would obviously be even more effective.

[22] It must be borne in mind that the patent in suit did not claim perfection but
claimed that when the kettle was placed on a slope a second spaced-apart actuator
which was uncovered by water as a result of it being tilted would serve as a safety
feature and be activated and cut off the electricity supply. The Jia Tai KSD688-A kettle
with a bridge between the two sensors and which effectively, at the most, had a
distance of 0,5 millimetres between the two sensors would be ineffective and would not
serve the purpose stated in the patent specification. In respect of that kettle the
infringement would not have been proved.

[23] It is necessary to record that a defence by Nu-World based on a mediation
agreement concluded upon direction of the Supreme People‟s Court in China was
specifically abandoned before us.

[24] In respect of the remaining kettles, Preller J disregarded the evidence and erred
in concluding that in relation to them there was no infringement.

[25] One further aspect requires brief attention. During the trial, counsel on behalf of
Nu-World was emphatic that he was not relying on obviousness as a defence. In an
exchange in the court below the following was said by counsel on behalf of Nu-World:
„The Defendant is not relying on obviousness, but it is relying on old art and as I made it clear
when I examined, and it ought to have been clear, I rely for the purposes of the Defendant‟s
case on the 85 patent.‟
Before us the same counsel insisted that he could rely on obviousness as a ground of
challenge to the validity of the patent and was not abandoning it. He took the view that it
was a point of law which could be decided on the evidence that was adduced. I
disagree. The defence of obviousness was never pleaded. The case was never
conducted on the basis that it was contemplated as a defence. More importantly, that
defence was expressly disavowed on behalf of Nu-World. The evidence required to
establish a defence of obviousness is of a different nature to that required to establish a
defence in relation to a defence of a lack of novelty. In this regard see Burrel’s op cit at
4.12.2 and Veasey v Denver Rock Drill and Machinery Co Ltd 1930 AD 243 at 281 et
seq.. This is not a case where allowing the defence of obviousness to be raised before
us would not be prejudicial.4 I do not intend to deal with this aspect any further.

[26] Following on the aforesaid conclusions the following order is made:
1. The appeal is upheld with costs including the costs of two counsel.
2. The order in the court below is set aside and the following is substituted:
„(a)
the defendant is interdicted from infringing claim 1 of South African Patent 95/4779 (“the
patent”) by making, using, disposing, offering to dispose of, or importing liquid heating
vessels containing Liang Ji LJ-06A, Liang Ji LJ-06 or Sunlight SLD-105A IL thermally
sensitive overheat controls or any other thermally sensitive overheat controls as claimed
in claim 1 of the patent;
(b)
the defendant is ordered to deliver up any product infringing the patent and any article or
product of which an infringing product forms an inseparable part;
(c)
as to damages:

4 See Alexkor Ltd & another v Richtersveld Community & others [2003] ZACC 18; 2004 (5) SA 460 (CC)
paras 43–44.

(i)
an enquiry is ordered as to the damages suffered by the plaintiff as a result of the
infringement of the patent by the defendant, alternatively as to the amount of a
reasonable royalty as contemplated in s 65(6) of the Patents Act, 1978 and
payment of the amount found to be due to it;
(ii)
in the event of the parties being unable to reach agreement as to the further
pleadings to be filed, discovery, inspection or other matters of procedure relating
to the enquiry, any of the parties may make application to the court for directions
in regard thereto;
(d)
the defendant is ordered to pay the plaintiff‟s costs, including the costs of two counsel to
the extent that such were employed and including the qualifying and attendance fees of
the expert witness Richard Moorhouse.‟

________________________
M S Navsa
Judge of Appeal

APPEARANCES:

FOR APPELLANT:

B du Plessis SC (with him C Cothill)

Instructed by:

Spoor and Fisher, Pretoria

Matsepes Attorneys, Bloemfontein

FOR RESPONDENTS:

A J Bester SC

Instructed by:

Bouwers Inc., Pretoria

Phatshoane Henney Inc., Bloemfontein
THE SUPREME COURT OF APPEAL OF SOUTH AFRICA

MEDIA SUMMARY OF JUDGMENT DELIVERED IN THE SUPREME COURT OF APPEAL

FROM

The Registrar, Supreme Court of Appeal

DATE

22 September 2015

STATUS

Immediate

Please note that the media summary is for the benefit of the media and does not form part of
the judgment.

Strix Limited v Nu-World Industries (20453/2014) [2015] ZASCA 126 (22 September
2015)

MEDIA STATEMENT

Today, the Supreme Court of Appeal (SCA) upheld an appeal by Strix Ltd (Strix), against an order by
the Court of the Commissioner of Patents, in which it was found that Nu-World Industries (Pty) Ltd
(Nu-World) had not infringed a patent belonging to Strix.  Overturning this decision, the SCA found
that the patent had been infringed, and accordingly granted an order (i) interdicting Nu-World from
making, using, disposing, offering to dispose of, or importing liquid heating vessels (effectively,
electric kettles) of a specific design; (ii) that Nu-World deliver up all products infringing the patent; and
(iii) damages.

The main issues before the SCA were, first, whether the patent was novel, and whether the defence
of lack of novelty was available to Nu-World even though it had not claimed in reconvention for the
revocation of the patent, and had not clearly pleaded this defence; and, second, whether the allegedly
infringing kettles belonging to Nu-World did in fact infringe the patent as described.

The facts were as follows.  Strix had registered a patent over the design for a ‘liquid heating vessel’
which inter alia included a thermally sensitive overheat control (effectively, a trip switch) which
comprised at least two sensors, in good thermal contact with the base of the container or the element,
and (critically) were spaced apart.  At the priority date of the patent in suit, it was common to have
overheat controls, but they only measured the temperature at a single location.  As a result, if the
kettle was tilted, and the water level was not parallel to the base of the kettle, it was possible for the
element or heated base to be partially underwater and partially above water.  If the sensor only

measured the temperature at an underwater location, the measurement would not accurately reflect
the heat of the above-water portions of the element or heated base, and as a result the overheat
control would fail to trip even though the kettle was overheating at the dry points.  The effect of the
sensors being spaced apart in the patent in suit was to provide an additional safety measure against
overheating because the temperature was sensed at two locations, increasing the chance that at
least one sensor would measure the temperature should the circumstance described above arise.

As to the first issue, the SCA held that a defence of lack of novelty is available even where one fails
to counterclaim for revocation of the patent. Further, although Nu-World’s pleadings were initially
vague, the defence was pertinently raised and fell to be considered. On the facts, the SCA held that
the defence failed, as the idea of spacing the two sensors apart in order to deal with the danger
described above was not part of the prior art, and the design was novel.

As to the second issue, the court a quo had concluded that the sensors in the allegedly infringing
kettles were too close together to be effective as a safety feature, and accordingly the kettles did not
infringe the patent in question.  The SCA rejected this conclusion in respect of all but one instance of
alleged infringement, and held that although the distance between the sensors was relatively small, it
was sufficient to ensure a substantially effective safety feature.  In respect of the remaining instance,
the two sensors were physically joined, and so the infringement was not proved.

The SCA accordingly upheld the appeal, and held that Strix’s patent had been infringed by Nu-World,
and granted the order described above.