Waipuna International Limited v Millwood Corporation Pty Ltd
[1997] APO 34
•28 July 1997
official notice
decision of a delegate of the commissioner of patents
Petty Patent: No. 661648 in the name of Waipuna International Limited
Title:Vegetation control method and apparatus
Action:Objection to Extension of Term under S.28. Hearing.
Decision:Issued .
Abstract:Claims valid, term extended. None of the informant’s evidence indicated that it was known at the priority date that the particular selection of features claimed would have the beneficial effects described in the specification and in the patentee’s evidence. Prior art vague and generic.
patents act 1990
decision of a delegate of the commissioner of patents
Re:Patent Application No. 661648 by Waipuna International Limited, application for Extension of Term under S.69, and Objection thereto under S.28 by Millwood Corporation Pty Ltd.
background
Application No.68869/94 was filed as a divisional application from application No. 40938/93, with a priority date of 7 May 1993. Petty Patent 661648 was sealed on application No.68869/94 on 27 July 1995 and the patentee applied for extension of the initial term on 2 May 1996. The informant’s S.28 notice was filed on 27 June 1996, on 28 June 1996 the informant applied under S.223 for an extension of time to file additional evidence, and additional evidence was filed on 28 June and 4 July 1996. The extension of time was granted by a delegate of the Commissioner on 15 August 1996, thus allowing the additional evidence to be adduced in the S.28 action. The patentee filed its evidence-in-answer on 15 November 1996.
The matter was heard in Canberra on 10 June 1997; the patentee was represented by Mr W Bennett, patent attorney; the informant was not represented.
the specification
The specification indicates that the invention relates to controlling weed growth by applying hot water under specified conditions. The invention is allegedly an improvement over prior art techniques involving herbicides, which can be an environmental problem, or involving physically removing the weeds, which is time consuming and labour-intensive. There are three claims defining the invention; claim 1 is the only independent claim and reads as follows:
“1. A method of killing or controlling weeds, comprising applying to the weeds pressurised hot water at a temperature substantially 75oC or above, wherein the pressurised hot water is delivered at a pump pressure in excess of 200 p.s.i. and at a flow rate in excess of 4 litres per minute.”
evidence
The informant’s S.28 notice asserts that the petty patent is invalid on three grounds, but the “reasons for the assertion” suggest that the grounds of novelty and lack of inventive step are the only serious grounds.
Inter alia, the notice refers to two other applications by the present patentee which were published after the priority date of the present application but which have earlier priority dates, viz:
58921/94 (“Aquaheat 1” (referring to the name of the original applicant), originally international application PCT/US 93/07543) and
55894/94 (“Aquaheat 2”, originally PCT/US 93/10479).
The informant’s evidence consists of the following:
A declaration by Stephen Krouzecky, dated 27 June 1996, with Exhibits SGK-1 to SGK-6. This declaration essentially relates to the searches done by Mr Krouzecky, the informant’s patent attorney up to 23 August 1996 (After that date Millwood has dealt with the S.28 matter itself).
A declaration by Stephen Krouzecky, dated 28 June 1996. This accompanied the S.223 application for an extension of time.
A declaration by Kenneth James, dated 27 June 1996, Exhibits KRJ-1 to KRJ-5 (filed 27-6-96) and Exhibits KRJ-7 and KRJ-9 (filed 4-7-96). Mr James is a lecturer and consultant with Melbourne University and has had 25 years experience working in the agricultural and horticultural industries.
I note that the informant’s evidence seems to be incomplete in that:
exhibits KRJ-6 (Levitt document) and KRJ-8 (Baker document), referred to in the correspondence and other parts of the evidence, have not been filed, and
a “further” declaration by Mr James, referred to in the S.223 application, has not been filed.
The patentee’s evidence consists of the following:
An affidavit of Dennis Tindall, dated 13 November 1996, with Exhibits DWT-1 to DWT-5. Mr Tindall is managing director of Waipuna International Limited.
An affidavit of Brian Silvester, dated 14 November 1996. Mr Silvester is the patentee’s patent attorney in New Zealand and he states that he has extensive knowledge of hydrostatics and hydrodynamics.
An affidavit of John-Paul Praat, dated 14 November 1996. Dr Praat is a research scientist with some experience in methods of non-chemical weed control.
An affidavit of Rodney Innes, dated 14 November 1996. Mr Innes is a thermodynamics engineer and an independent consultant to the patentee.
In his declaration, Mr James alleges that the invention lacks an inventive step in the light of the common general knowledge and that the specification is insufficient; in particular he states:
“Whilst it is true that conventional weed control equipment does not use hot water as the method to kill weeds, the concept of using hot water to kill plants, particularly in laboratory situations, has been used for many years.” (parag.6)
“... the contribution being made that is new to the art in what is taught or disclosed in the Waipuna specification appears to be in the apparatus developed ... rather than the method per se.” (parag.10)
“... after reviewing the published information it would be essential that in order to kill plants, the temperature of the plant cells must be raised above 65-70oC for a duration of time ranging from 3 seconds to 10 minutes. Higher temperatures substantially above 75oC would permit shorter durations to achieve the same level of weed kill. Temperatures of hot water up to 100oC would therefore be even more effective with spray equipment. This knowledge is available from an examination of the published literature on the effect of heat stress in plants.” (parag.22)
“It would ... seem more appropriate to quote values of pressure at the nozzle outlet than at the pump.” (parag.25)
“ ... factors relating to pressure in spray equipment are many and various. One quoted pressure is not sufficient to fully define the function nor the purpose of the selected pressure. In the claim [this integer] is so general as to lack precise definition as to purpose and function.” (parag.36)
“... [the flow rate feature of claim 1] does not adequately define the quantity of hot water (and thus heat) that is applied to weeds, without further defining forward speed. To illustrate this point, if the outlet were stationary, all the water, no matter the flow rate, would be deposited on the one location.” (parag.40)
“... the basic concept of killing weeds and plants using hot water has been known for centuries and has been commonly used in laboratories in Australia for decades. The remaining integers of each of the claims do no more than add technical limitations to this basic concept ... These technical limitations would be immediately obvious to any skilled person having a basic knowledge of conventional agricultural and horticultural spraying apparatus an techniques that were common knowledge in Australia before 7 May 1993 ...” (parag.45)
Submissions
The substantive part of the patentee’s written submissions filed at the hearing are as follows:
“The present invention
“The present invention relates to a method of killing or controlling weeds by delivering liquid heat in the form of pressurised heated water to the weed.
“The use of hot water to kill weeds is acknowledged as being not new. However, the present invention is a selection in which the values of parameters (relating to the manner in which the liquid heat is applied) are specified. These values have been shown to provide a substantially enhanced result (see DWT-1).
“The prior art
“KROUZECKY (1) [Declaration of 27 June 1996] raised 4 documents:-
“1. ‘Weeds in Hot Water’ Volume 1, Issue No 7 of Acres Australia (note: this is Aquaheat)
- there is no evidence that this document was published prior to 7 May 1993.
- it is stated that the article was published in May 1993, however there is no evidence to support this.
- even if it is accepted that the article was published in May 1993, that does not mean it
was published prior to 7 May 1993.
- it is stated that articles are required to be delivered to the editor 2-3 weeks prior to
publication - this does not mean that this particular article was.
- even if it accepted that (a) the article was published in May 1993 (not proven.), and (b)
the article was delivered 2-3 weeks prior to publication (not proven), this does not mean
that the editor was in possession of the article prior to 7 May 1993 (eg. article delivered,
say, 10 May 1993 and published, say, 28 May 1993).
- if it is accepted that the editor was in possession of the article prior to 7 May 1993, it
should be noted that correspondence between an editor and his source is confidential
until publication.
- the article itself simply states that hot water can be used to control weeds. No mention
is made of the parameters relating to the manner in which the water is applied to the
weeds.
“2. Australian Patent Application 58921/94 (Aquaheat 1)
- published 29 March 1994
- priority date is, prima facie, 26 August 1992.
- the article discloses the use of a heated liquid spray to control weeds. The spray may
include active ingredients at relatively low concentrations. Temperatures of 100- 240 F
are mentioned.
- there is no mention of pressure or flow rate.
- it seems that Aquaheat came to an appreciation in August 1992 that heat could be used
to reduce the concentration of active ingredients required. This has been extrapolated
to zero, ie. pure water.
“3. Australian Patent Application 55894/94 (Aquaheat 2)
- published 26 May 1994.
- priority date is, prima facie, 6 November 1992
- the article discloses the use of a high pressure liquid spray to control weeds. The spray
may be heated and may include active ingredients at relatively low concentrations.
Temperatures of 100-240 F are mentioned. Pressures of 100-4000 psi are mentioned.
- it seems that Aquaheat came to an appreciation in November 1992 that high pressures
can also be used to kill plants via mechanical damage to the plant. The high pressure
treatment may be followed by heat and chemicals as per Aquaheat 1.
“Page I lines 18 to 28 of Aquaheat 2 should be closely read.
‘As is set forth in my prior application Serial No. 07/935,865 (ie Aquaheat 1), it has been
discovered that effective control of the undesirable substances can be obtained utilizing
from zero to one-half the normally required chemical treatment materials by first heating
the liquid spray material to a temperature of from about 100 F to about 240 F before
spraying. It has now been discovered that effective control can be obtained by spraying
the liquid, heated or unheated, at pressures of from about 100 psi to about 4000 psi.’
“It is thus apparent that Aquaheat has not arrived at the present selection. Rather, Aquaheat has treated heat and pressure as two distinct unrelated parameters each of which is individually capable of achieving weed control, albeit usually with a small amount of active ingredient. See Silvester para 12.
“4. US Patent 2 605 137
- this document discloses apparatus for mixing a ‘conveyer liquid’ with an active ingredient, wherein the conveyer liquid is supplied at variable pressure.
“JAMES raised 4 documents:-
“1. Extract from thesis entitled ‘The Affects of High Temperatures on the Growth...’
- whilst this document is said to have been publicly available since 1981, there is no
evidence to confirm this.
- this document simply illustrates that different species of plants have different capacities
for withstanding heat. The heat may be either dry or wet. If the heat is wet, the plant is
immersed under laboratory conditions.
“2. Extract from ‘The UC System for Producing...’
- whilst this document is said to have been publicly available in Australia since before
7 May 1993, there is no evidence to confirm this.
- this document relates to the treatment of soil with steam to kill pathogens prior to
potting plants.
“3. Extract from ‘Plant Physiology’
- whilst this document is said to have been publicly available in Australia since before
7 May 1993, there is no evidence to confirm this.
- this document simply observes that plants have an optimum temperature for growth and
photosynthesis.
“4. Extract from ‘The History of Gardens’
- whilst this document is said to have been publicly available in Australia since before 7 May 1993, there is no evidence to confirm this.
- the passage attributed to Magnus simply refers to the use of boiling water to prepare the ground.
“KROUZECKY (2) [Declaration of 28 June 1996] raised 3 documents of which he alleges 2 are relevant:-
“1. US Patent 1,042,688
- there is no evidence that this document was published in Australia prior to 7 May 1993.
- the document refers to the use of hot pressurised water (from a steam locomotive) to kill weeds.
- there is no disclosure of the parameters of the present invention which provide the enhanced result.
“2. US Patent 1, 195,027
- there is no evidence that this document was published in Australia prior to 7 May 1993.
- the document refers to the use of hot pressurised water or steam (from a steam locomotive) to kill weeds.
- there is no disclosure of the parameters of the present invention which provide the enhanced result.
“Summary of prior art
“None of the prior art documents discloses the parameters of the present invention which provide the enhanced result.
“Selections
“A. If a generic disclosure is broad, vague, and/or speculative, then that disclosure will not
deprive a claim of its novelty ([Patent Examiner’s] Manual 3.6.6).As discussed above, the disclosures of the prior art are broad and vague. They certainly do not give clear instructions to apply liquid heat in the manner of the present invention which provides substantial and unexpected results.
“B. Criteria
1. the selection must be based on some substantial advantage gained or substantial
disadvantage avoided.
2. the whole of the selected members must posses the advantage.
3. the selected members must have a character peculiar to the selected members.
(Manual 3.6.6.1)The present invention provides a superior result in killing weeds.
“C. It is necessary that a selection patent describe the advantages of the selection and an
amendment of the specification to describe the advantages is permissible
(Manual 3.6.6.2)“D. A selection has the quality of being unexpected. (Manual 3.6.6.3)”
“The parameters of the present invention were not predictable. Regarding temperature: there was no way of predicting that water would be superior to steam, although having settled on water it was perhaps reasonable to assume that boiling water would be the most effective. Regarding pressure and flow rate: there was no way of predicting these values. Because it is desirable to deliver the water at close to boiling it is necessary to initially heat the water to above 100 C to allow for heat losses in delivery to the weed. Given that the water is at greater than 100 C, it is necessary to pressurise the water to maintain it in the liquid phase and avoid steam pockets. It is also necessary to pressurise the water to drive it through the applicator nozzle at the desired rate. Having said that, very high pressures are not desirable as this can cause the creation of fine droplets which may be subject to airborne drift and will not "soak" the weed. Also very high pressures are undesirable as they would damage footpaths etc and also dictate the need for substantial pressure vessels.”
The informant was not represented at the hearing and did not file any written submissions.
decision
The informant made no submissions in this matter, but the S.28 action has to be resolved, and generally I am required to consider the public interest that the petty patent should not be extended if it is shown to be invalid (see Tate v Haskins 53 CLR 594); thus I have given the informant’s evidence due consideration despite its lack of submissions.
Re novelty and inventive step, the evidence indicates that it is known to kill plants or weeds with steam or hot water, and the present claims are directed to such a known method, albeit characterized by specific operating parameters; so the question arises whether the specific parameters are novel and/or involve an inventive step in the light of the generic prior art. It could be argued for example that the claims are directed to a “mere working direction” or a “mere use of a known process”; see Commissioner v Lee 16 CLR 138 and Reitzman v Grahame-Chapman & Derustit [1950] RPC 178 for example.
It is not stated specifically in the specification that the concept of killing weeds with steam or hot water is well known, but the evidence suggests that it is common knowledge, and I think an addressee of the specification would be aware of this common knowledge. The specific parameters of the hot water temperature, pressure and flow rate distinguish the invention from the prior art and therefore it is appropriate to conclude that the specific parameters are essential features of the invention.
In my view, the claims are directed to a patentable selection and are therefore not a mere working direction or a mere use of a known process. The claims are patentable firstly because the prior art is generic and vague compared to the specific parameters set out in the claims. In General Tire & Rubber Co v Firestone Tyre Co [1972] RPC 457 the principle was set out that a vague generic disclosure will not deprive a claim of its novelty, viz:
“Apparent generality or a proposition not true to its full extent will not prejudice a subsequent statement which is limited, accurate, and gives a specific rule of practical application ... the prior knowledge of an invention to avoid a patent must be knowledge equal to that required to be given by a patent, namely such knowledge as will enable the public to perceive the very discovery, and to carry the invention into practical use.”
Re the applicant’s own later specifications cited in the S.28 notice and referred to above; there is no disclosure in these applications which would lead to a “whole of contents” novelty objection to the present claims, since the claims and inventive concepts in those applications do not include all the abovementioned essential features of the present claims.
The claims are patentable secondly because there appears to be some merit in the invention. This is evident firstly in the specification, which sets out example embodiments of the invention and indicates how these give an improved result over the prior art. The patentee’s experts also indicate that there is some merit in the invention. For example, Dr Praat declares:
“There is no doubt that the idea of killing weeds by application or immersion of hot water is not new. However, to my knowledge the Waipuna system is unique in that it is a commercially viable hot water based weed control system which can be used in the field. The system successfully competes directly with herbicide based systems for urban weed control. The evidence of this success is in the wide acceptance and use of the system both locally and internationally over the last three years.”
The patentee’s evidence also indicates that the merit of the invention is due to the specific combination of parameters. For example, Mr Tindall declares:
“In brief it is a particular combination of pressure, volume and temperature that in a commercial situation creates a particularly efficacious weed treatment method”
and Mr Innes declares:
“The declaration of James and the prior art attachments to the declarations of Krouzecky simply identify individual parts of the method as prior art. There is no teaching in the various alleged items of prior art raised that would lead even a person skilled in the weed killing art to the combination of pressure, temperature and flow rate claimed in Australian Petty Patent 661648.”
Commercial success can be an indicator of inventive ingenuity; see Lister & Co Ltd’s Patent [1966] RPC 30 for example. Taking the parties’ relevant evidence into account, I am of the view that Mr James’ allegation that the invention is obvious is contradicted by the patentee’s experts, and that the weight of evidence is clearly in the patentee’s favour.
Generally, in my view, none of the informant’s evidence indicates that it was known at the priority date that the particular selection of features as claimed in the petty patent would have the beneficial effects described in the specification and in the patentee’s evidence. Thus I am satisfied that the claims are novel and involve an inventive step over the prior art.
Re Section 40 matters, firstly I will comment on Mr James’ allegation that the specification does not include enough details relating to some of the parameters. In this matter, the patentee’s evidence suggests to me that the specification does sufficiently describe a best method of performance of the invention. For example, in paragraph 4 of his declaration Dr Praat indicates that it is not necessary to specify exact parameters, within the range of parameters claimed, because “different applications (variations in target weeds) will require different combinations of temperature, pressure, water flow and application speed to provide acceptable control.” I accept this argument; the invention can be a selection of parameters from the broad generic concept yet still have some scope for practical variations.
In response to Mr James’ allegation that the flow rate feature of claim 1 does not adequately define the quantity of hot water (and thus heat) that is applied to weeds, without further defining forward speed, Mr Tindall states:
“...if say a 250 millimetre head is used to treat 1 ha then the Waipuna system will use the same volume of water if the treatment head was 1 metre wide. Speed of application will logically be quicker with the larger head. The larger head will require a variance of heat input and pressure to match the higher volume. This will be clear to a skilled practical man in the field set forth ...”
Generally, I think the specification relates to relatively simple technology, and apart from the relatively minor issues raised by Mr James, the parties involved seem to have been able to construe the specification without difficulty. Thus I am satisfied that the specification complies with Section 40.
conclusion
I find that the claims of Petty Patent No.661648 are valid, and accordingly I extend the term under S.69(2). Applying the usual practice of costs following the event, I award costs against Millwood Corporation.
John Welsh
Delegate of the Commissioner of Patents
Patent attorneys for the patentee: Pizzeys, Woden ACT
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