Hans Sasserath GMBH & Co. Kg and Another v Advanced Valves CC

• Jurisdiction: http://justis.com/jurisdiction/166,South Africa
• Judge: AC Basson J
• Judgment Date: 05 September 2022
• Docket Number: 42291/2021; 2005/09552
• Hearing Date: 05 September 2022
• Court: Commissioner of Patents
• Citation: 2022 JDR 2617 (COP)

AC Basson J:

Commissioner of Patents:

Introduction:

[1]

The first plaintiff (Hans Sasserath Gmbh & Co. KG) is the proprietor of South African patent 2005/09552 (the patent) and the second plaintiff (Halograph (Pty) Ltd) is a registered licensee of the patent in South Africa (the plaintiffs). The plaintiffs claim that the patent is being infringed by the manufacture and sale by the defendant (Advanced Valves CC) of a vent valve (the AV vent valve - also known as a "vacuum breaker") in South Africa.

[2]

Although the defendant admits that it manufactures and sells the AV vent valve, it denies that the vent valve it manufactures and sells, falls within the scope of the claims of the patent-in-suit and therefore denies infringing the patent. There is no attack on the validity of the patent.

[3]

The dispute before the court is whether the defendant's AV vent valve falls within the scope of one or more of the claims of the patent. Although there are 6 claims, the invention is principally the subject of claim 1. Claim 1 can be divided in various "integers" or features. In respect of claim 1 there are three main disputes. At the heart of the dispute between the parties is whether the small plastic body situated in the vent valve which rises to the top to close the opening to the atmosphere, is a "float" within the meaning of the patent specification. For convenience sake I will refer to this plastic body of the vent valve as the "closing device".

Legal principles relating to infringement:

[4]

Section 45 of the Patents Act [1] explains that the effect of a patent is to grant to the patentee in the Republic of South Africa, for the duration of the patent, the right to exclude other persons from making, using, exercising, disposing, or offering to dispose of, or importing the invention, so that he or she shall have and enjoy the whole profit and advantage accruing by reason of the invention.

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[5]

In order to determine whether this right granted to the patentee is being infringed, the court must first determine what it is that was invented and the scope of the patent. In the present matter, this determination hinges, to a large extent, on the interpretation of the word "float" and whether a "hot water system of a drinking water heater" equites to a "geyser" as commonly understood in the South African plumbing environment. Only once content or meaning has been given to the nature and scope of the patent, will the invention be compared with the alleged infringement in order to determine whether the two are in substance the same. The court in Gentiruco AG v Firestone SA (Pty) Ltd [2] explains:

"The main issues in this appeal are such that our very first task is to ascertain the nature of the invention as claimed and its precise scope (see, for example, Veasey's case, supra at p. 280; cf Frank & Hirsch's case, supra at p. 756E). 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."

[6]

Interpreting the nature and scope of the patent claims requires analyzing the following two components of the patent-in-suit: The first is the body of the specification which informs the reader, normally in general terms, how to put the invention into practice. It has been stated that the body of the specification instructs the public on how to carry out the invention once the patent monopoly has ended. [3] The second is a consideration of the claims. This is the more important component of the enquiry and fulfils a separate and distinct function from the body of specification. It is the claims alone that define the patent monopoly, [4] or put differently, the invention. A claim for an infringement and the

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scope of a claim is assessed with reference to the claim, not the body of the specification. However, having said this, a patent claim may, where there is, for example, uncertainty about what the ambit of a claim is, be interpreted in the context of what is stated in the body of the specification of the patent. The court in Roman Roller CC and another v Speedmark Holdings (Pty) Ltd [5] explains:

"In determining whether a patent claim stakes its monopoly with a sufficient degree of clarity, the Court must view the patent through the eyes of the skilled addressee in the relevant art; and the Court must take into account that such addressee is expected to use reasonable skill and intelligence in interpreting the language of the patent. He is not required to struggle unduly with it, but he must make the best of it and not adopt an attitude of studied obtuseness. If words or expressions in a claim are affected or defined by what is said in the body of the specification, the language of the claims must be construed accordingly. Moreover, uncertainty or ambiguity in a claim may be resolved by what appears in the body of the specification, which may be thus resorted to not only when the language in question has been expressly defined in the body of the specification, but also, in the absence of such definition, where there is material in the body from which the intention of the draftsman can be gathered. Where the words permit it, an interpretation should be adopted which is consistent with the description of the problem to be overcome and the method of doing so described in the body of the specification. Another source of elucidation of apparently unclear language may be the prior art itself (See generally Helios Ltd v Letraset Ltd 1970 BP 495 (T) at 498G-499B, 500B-G, 503B-C; Letraset Ltd v Helios Ltd 1972 (3) SA 245 (A) at 249H-251B.)"

[7]

The enquiry in determining whether an infringement has occurred is neatly summarized by the court in Aktiebolaget Hassle and another v Triomed (Pty)

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Ltd: [6]

"In Letraset Ltd v Helios Ltd 1972 (3) SA 245 (A) at 274G - H, Van Winsen JA, writing for the Court on that issue, described the nature of the enquiry into infringement as follows:

'The determination of the question as to whether or not plaintiff has proved an infringement of his patent turns upon a comparison between the article or process, or both, involved in the alleged infringement and the words of the claims in the patent. If the article or process falls within the ambit of the claims, properly construed; an infringement is proved. But the article or process will not be regarded as falling outside the scope of the claims if such differences as the comparison may disclose are not matters of any substance. In making the comparison the law looks at the essence of what is contained in the claim and will not allow what is described as the "pith and marrow" of the protected invention to be pirated. The evaluation of what is the substance or essence of an invention is a matter for the "good sense" of the judicial tribunal seized with the enquiry.'

[8]

The enquiry into infringement requires a comparison between the allegedly infringing article or process against the language of the claim. This enquiry will require of a court to construe the language of the claim. Words must be interpreted purposively so as to extract from it the essence, or the essential elements of the invention or as the court so aptly put it in Aktiebolaget [7] the "pith and marrow" of the protected invention. In doing so, the court will use its "good sense". The court continued to say:

" . . . a patent specification is a unilateral statement by the patentee, in words of his own choosing, addressed to those likely to have a practical interest in the subject matter of his invention (ie "skilled in the

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art"), by which he informs them what he claims to be the essential features of the new product or process for which the letters patent grant him a monopoly. It is those novel features only that he claims to be essential that constitute the so-called "pith and marrow" of the claim. A patent specification should be given a purposive construction rather than a purely literal one derived from applying to it the kind of meticulous verbal analysis in which lawyers are too often tempted by their training to indulge. The question in each case is: whether persons with practical knowledge and experience of the kind of work in which the invention was intended to be used, would understand that strict compliance with a particular descriptive word or phrase appearing in a claim was intended by the patentee to be an essential requirement of the invention so that any variant would fall outside the monopoly claimed.' [8]

[9]

At the risk of repeating what is stated in various judgments, the following important principles emerge: Firstly, the court is required to compare the article and/or process which form the subject of the alleged infringement, with the words of the claim. If the articles or process falls within the ambit of the claims, an infringement will have been established. Axiomatically this will require the court to interpret the various integers of the claims. Secondly, the emphasis is on the substance or essence of what is contained in the claim or as the court described it in Aktiebolaget [9] the "pith and marrow". Thirdly, common sense or good sense informs the court what the essence or substance of the claim is. Fourthly, the language of a claim must be construed purposively. In doing so, a court should guard against getting entangled in a process of "meticulous verbal analysis". The aim is extracting the essence of the claim. Fifthly, the essential question is "whether persons with practical knowledge and experience of the kind of work in which the invention was intended to be used, would understand that strict compliance with a particular descriptive word or phrase appearing in a claim was intended by

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