Top view of the Elbroc rig
[8] Having considered the claims of the patent the Commissioner found that the Elbroc drill rig did not infringe the
patent as its carriage equipment was not located "between" its two props. In interpreting the word
"between" the learned Judge adopted the dictionary meaning "linearly between," and found that because the
carriage in Elbroc's drill rig was offset from the linear space between the props there had been no
infringement of the patent. He also held that Orica's interpretation of the word "between" amounted to an
impermissible extension of the meaning of the word because it sought "to include a carriage which is offset at
a right angle to the colinear line between the pair of telescopic props at an undefined and unspecified
distance from the space between the two props".
[9] In this Court Orica persisted in its contention that on a proper construction the patent claims required only
that the drill carriage be located in the space between the two props, even if not in the same linear plane as
the props. It was submitted on behalf of Orica that Elbroc's argument incorrectly equated the word "space"
with the word "line" and ignored the context of the specification and the three dimensional configuration of
the props, together with the space separating them.
[10] On the other hand, Counsel for Elbroc submitted that the correct approach is to use "the language of the
claims", that being the ordinary dictionary meaning of the word "between".
[11] Section 45(1) of the Patents Act provides for protection of a patentee against the making, using, exercising,
disposing or offering to dispose of or importing of the patentee's invention. The protection endures for the
Page 801 of [2017] 2 All SA 796 (SCA)
duration of the patent.2 The invention is defined in the patent and the courts have indeed held that the exact
nature and scope of the invention and the monopoly claimed for it by a patentee (the essential constituent
features of the patent) must be determined by interpreting the patent claims.3 In the wellknown case of
Gentiruco AG v Firestone SA (Pty) Ltd4 this Court noted that in dealing with aspects relating to patent
infringements, its first task is to "ascertain the nature of the invention as claimed and its precise scope.
Accordingly the specification, and especially the claims, have to be construed; it is, after all, the instrument on
which the letters patent were applied for and granted and it must therefore necessarily govern those
issues."5 It was pointed out that "if the object of the claims is borne in mind, their meaning, as ascertained
from their own language, must prevail over the rest of the specification" because that is where those to
whom the patent is addressed, will look to determine if they are trespassing.6
[12] The correct approach to interpreting the claims in the context of the patent as a whole, has been described in
the following terms. In Harrison v Anderson Foundry Company (1876) 1 AC 574 (HL) the court held:
"The office of a claim is to define and limit with precision what it is which is claimed to have been invented and
therefore patented.
Where a claim is clearly and distinctly made, there can be no necessity for a patentee to distinguish between what is
disclaimed and what is claimed. It is enough to say to Lord Gifford's suggestion that everything which is not claimed is
disclaimed."
In Multotec Manufacturing (Pty) Ltd v Screenex Wire Weaving Manufacturers (Pty) Ltd 1983 (1) SA 709 (A) at
721CE [also reported at [1983] 1 All SA 314 (A) Ed], Corbett JA observed that:
"[T]he Court should always guard against too 'textual' an approach in the interpretation of claims in a patent
specification. It is true that it is in the claims that a patentee stakes out and defines his monopoly; and that the claims
must be looked at in order to determine whether an infringement has taken place. But by peering too closely at the
language of a claim the Court may overlook an infringement which takes the substance of the invention. . . . In this
context it is often said that an infringer who takes the 'pith and marrow' of the invention commits an infringement
even though he omits an inessential part or substitutes for that part a mechanical equivalent. . . . Where the alleged
infringer has deviated in regard to some feature from the invention as literally claimed in the specification, it may
often be a matter of considerable difficulty to determine whether the deviation relates to an essential or a non
essential feature of the relevant claim or claims. In relation to this I would favour the approach stated by Lord Diplock
in . . . Catnic Components Ltd and Another v Hill and Smith 1981 Fleet Street Reports 60 . . . (at 6566)."
[13] In Electrical and Musical Industries v Lissen Ltd (1938) 56 RPC 23 [UK] at 39 Lord Russell of Killowen whilst
highlighting the function served by
Page 802 of [2017] 2 All SA 796 (SCA)
patent claims, clearly stated that the claims derive their colour from the context set out in the body of the
specification. The learned Judge held:
"The function of the claims is to define clearly with precision the monopoly claimed, so that the others may know the
exact boundaries of the area within which they will be trespassers. Their primary object is to limit and not to extend
monopoly. What is not claimed is disclaimed. The claims must undoubtedly be read as part of the entire document,
and not as a separate document; but the forbidden field must be found in the language of the claims and not
elsewhere. It is not permissible in my opinion, by reference to some language used in the earlier part of the
specification, to change a claim, which, by its own language is a claim for one subjectmatter, which is what you do
when you alter the boundaries of the forbidden territory. A patentee who describes an invention in the body of a
specification obtains no monopoly unless it is claimed in the claims . . .
A claim is a portion of the specification which fulfils a separate and distinct function. It and it alone defines the