FLAKT AB v Metallgesellschaft Aktiengesellschaft

[1992] APO 75

OFFICIAL NOTICE

decision of a delegate of the commissioner of patents

Application        :    No. 550420 in the name of FLAKT AB

Title:    Control Device for an Electrostatic Dust Separator

Action: Opposition under section 59 (Patents Act 1952) by METALLGESELLSCHAFT AKTIENGESELLSCHAFT

Decision:    Issued            .  Section 40 defects. Applicant given opportunity to amend.

patents act 1990

decision of a delegate of the commissioner of patents

Re:Patent Application No.550420 by FLAKT AB and opposition thereto, under Section 59 of the 1952 Act, by METALLGESELLSCHAFT AKTIENGESELLSCHAFT

background

Patent application 550420 for an invention entitled "Control Device for an Electrostatic Dust Separator" was filed on 21 July 1982 as 86257/82 and claims priority from a basic application filed in Sweden on 28 July 1981. The application was advertised accepted on 20 March 1986, and on 12 June 1986 Metallgesellschaft Aktiengesellschaft lodged notice of opposition under section 59 of the Patents Act 1952. Evidence-in-support was served on 20 November 1987. The applicant did not serve evidence-in-answer but requested amendment of the complete specification under Section 77 of the 1952 Act. The request was not opposed and allowance of the request was advertised on 12 July 1990.

The opposition was heard in Canberra on 7 October 1992. The applicant was represented by Mr A J F Ward of Griffith Hack & Co, Melbourne , and the opponent was represented by Mr S K Plymin of Watermark Patent & Trademark Attorneys, Melbourne.

As the application was both filed and advertised accepted before the commencement of the Patents Act 1990, the provisions of section 234(3) of the 1990 Act, and Regulation 23.3, are applicable.

Although the notice of opposition specifies the grounds of opposition listed in paragraphs c) to i) of sub-section 59(1) of the 1952 Act, the evidence and submissions at the hearing were confined to the grounds of lack of novelty, prior publication, obviousness, and non-compliance with section 40.

THE SPECIFICATION

I will now consider the patent specification as amended under section 77 of the Patents Act 1952. I find that it relates to a control device for an electrostatic dust separator of the type in which direct current and voltage at the poles of the separator is regulated by controlling the switching of rectifiers in the AC power supply line. In particular, the invention is concerned with an arrangement including a data processor which responds to the sensing of direct current and voltage as well as the zero-point in the AC power supply and controls the timing of switching signals provided to the rectifiers.

The specification commences by discussing the technical field, prior art and the technical problem. It indicates that it has been difficult to produce a simple control device that can adapt to variations in particle material, size or quantity and that can control current and voltage values for maximum separation efficiency. There has also been the problem of controlling several dust separators working together as communication between master controller and individual control units has been complicated.

The specification continues with a summary of the invention in the form of a consistory statement which corresponds to Claim 1 followed by the detailed description of the preferred embodiments of the invention with reference to 14 drawing figures.  The specification concludes with five claims.

Claim 1 is as follows:

1. A control device for an electrostatic dust separator, having electrodes, an a.c. power supply with rectifiers to generate intermittent power impulses and means to convert said power impulses to direct current, which is supplied to said electrodes, adapted to control, in relation to determined levels, a direct current by a first means and d.c. voltage by a second means in the dust separator and by a third means sensing the zero point in the a.c. voltage of said a.c. power supply, the instant of time for switching said rectifiers, wired into the power supply lead to said dust separator, characterized in that a signal representing the determined level for the current is supplied to amplifiers, connected to an A/D converter and a data bus connected to a data processing unit, that a signal representing the determined level for the voltage is connected to amplifiers connected to an A/D converter and a data bus connected to said data processing unit, that an information representing the passage through zero of the supply voltage is connected to an adapter circuit including flip‑flop circuit, connected to said data processing unit, that one of the outputs, from said flip‑flop circuit is connected to a delaying circuit connected to one input of said processor and another output of said flip‑flop circuit is connected to a second input of said processor, that the data of the data processing unit is so arranged that in relation to the levels of the actual direct current and d.c. voltage in the dust separator and with reference to the instant of time when said a.c. power supply voltage passages through zero, it will not only calculate a specific time interval for the switching of the rectifiers but also generate switching pulses, and in that said switching pulses are fed to adapter circuits from the data processing unit to said rectifiers.

EVIDENCE

The evidence-in-support consists mainly of a statutory declaration by Wigand Shaletzki who is the Manager of Electrical and Instrument Engineering at Lurgi (Australia) Pty Ltd which is a subsidiary of the opponent, Metallgesellschaft Aktiengesellschaft. Mr Shaletzki refers to a number of documents which are allegedly publications of relevant prior art and further indicates that he was aware of the devices described in these documents prior to the priority date of the present application. He also makes other observations as to common knowledge in the art in Australia before the priority date and refers to a number of features of the claims as accepted. The evidence-in-support also includes a declaration by Wayne McMaster that comprises information relating to the date that certain documents referred to by Mr Shaletzki became available in Australia.

While the evidence-in-support is directed to the application as accepted Mr Plymin contended that the evidence was still appropriate to the application as amended. I will refer to the relevant parts of the evidence at the appropriate points in my decision.

SECTION 40

At the hearing Mr Plymin addressed certain deficiencies he saw in the wording of the specification and claims. In particular he found claim 1 to be unclear for the following reasons:

1. There is no indication of what is meant by "determined levels" at line 6.

1. Antecedents for the terms "direct current" (line 6), "d.c. voltage" (line 7), "the determined level" (lines 11-12) "the current" (line 12) and "the voltage" (line 15) are unclear.

1. It is unclear at lines 12 and 15 whether the references to amplifiers is to two or more amplifiers in each instance or to two amplifiers in total.

1. It is uncertain whether the A/D converter and data bus referred to at line 16 are the same elements as defined at line 13 or additional to these elements.

1. It is unclear what constitutes "an information" at line 17 and how it is related to the "third means" at line 8.

1. First, second and third means are defined at lines 6-8 but these "means" are not referred to subsequently in the claim.

1. The is no antecedent for "said processor" at lines 23-24.

1. It is unclear what the "data" of the processing unit comprises (line 24) and from where the data processing unit receives the level of actual direct current. Notably the claim as accepted referred to the first, second and third means as sensing the direct current, d.c. voltage and zero point respectively.

Mr Plymin then argued that it was not clear whether the "master control unit" in claim 2 was to be considered part of the "control device" or part of the electrostatic dust separator as a whole. He also noted that the reference to several dust separators working in parallel at page 3 lines 24-25 appears intended to refer to separators working in series

In relation to fair basis Mr Plymin referred to the prior art acknowledged on pages 2-3 of the specification and suggested that if that was the starting point then the invention described in the specification may relate in fact to a control system for controlling a number of dust separators in series. If that is the case then the claims fail to define the invention and are therefore not fairly based on the description.

Mr Ward for his part admitted that some passages of claim 1 were somewhat unclear, but that it could be understood and when read by someone skilled in the art, particularly when reference is made to the specification, whatever doubts there were could be resolved. He went on to make the following points:

a)Claim 1 covers a control device adapted to be used in an existing electrostatic dust separator. Claim 2 adds the master control unit into the device claimed.

b)In claim 1 "determined levels" are recorded levels of current and voltage.

c)The "direct current" (line 6) and "d.c. voltage" (line 7) are clearly the direct current and voltage referred to earlier in the claim.

d)The "determined level for the current" (line 12) and the "determined level for the voltage" (line 15) are clearly tied to the previous reference and again "determined level" could be read as "recorded level".

e)It does not matter that there is two references to "amplifiers connected to an A/D converter and a data bus connected to said data processing unit" as you could clearly have separate circuits with separate integers to achieve this.

f)In relation to "an information" (line 17) "information" means where the cross-over point of the AC waveform is and when it occurs. From a linguistic point of view the word "an" should be deleted.

g)The circuits discussed in the latter part of claim 1 namely the amplifiers, A/D converters and data bus connected to the data processing unit effectively relate to the first, second and third means defined earlier in the claim.

h)"said processor" (lines 23-24) is an error but logically it must refer to the data processing unit.

1. The data of the data processing unit is the inbuilt software used to carry out the control operation and it is not necessary for the claim to say any more than that.

In relation to the question of fair basis Mr Ward indicated that while the invention provided a control arrangement which simplified signal communication and would accordingly be more useful when used in a series of dust extraction units working together, the restriction of the claimed invention to this application was unreasonable. He also acknowledged that the reference at page 3 lines 24-25 should be to several dust separators working in series.

Having considered both submissions I find that I am in agreement with a number of points made by Mr Plymin. Mr Ward submitted that while portions of claim 1 were "somewhat" unclear the claim could be understood when reference was made to the description as a whole. However it is a requirement that the language of the claims be sufficiently unambiguous so that there is no uncertainty as to what competitors may not do and in this regard it is not legitimate to narrow or expand the scope of the words in the claim by adding "glosses" from other parts of the specification (Decor Corp v Dart Industries 13 IPR 358). In any case I believe that certain parts of claim 1 are unclear even after reference is made to the description.

In particular I find that at lines 5-9 of the claim it is not clear that the words "adapted to control" relate only to "the instant of time for switching..." and it is not apparent that the "determined levels" are recorded levels as suggested by Mr Ward. The purpose of the first and second "means" is unclear and in this regard I note that the claim before amendment referred to "first means sensing the level of direct current in said separator" and "second means sensing the d.c. voltage in the separator". Also I agree with Mr Plymin that the relationship between the first, second and third means defined here and the features recited in the remainder of the claim is unclear.

Furthermore I agree with the points made by Mr Plymin at 2, 5, 7 and 8 above. I do not however agree with his submissions in relation to points 3 and 4 which concern passages of the claim that I believe would be readily understood by a person skilled in the art. In relation to claim 2, I do not see any ambiguity in the reference to the master control unit and agree with Mr Ward's submission on this point.

On the question of fair basis I agree with Mr Ward that the invention in its broadest form is not restricted to the control of a number of dust collectors in series. I do however find the description under the heading "Technical Problem" somewhat misleading in that it is not clear how the claimed invention solves the alleged problems of the prior art stated in that passage. In this regard the problem solved by the invention claimed appears to be timing inaccuracies caused by the effect of interrupt collision in the data processor as described at pages 18-20. Nevertheless the invention claimed is broadly described in the specification and is fairly based.

In light of my consideration of the submissions made by both parties I find that the complete specification does not comply with the requirements of section 40.

PRIOR PUBLICATION AND NOVELTY

In his statutory declaration Mr Shaletzki refers to four prior art documents:

• "The Siemens article" - Siemens-Zeitschrift 45(1971) Issue 9, pp 567-572, entitled "Elektrofiltersteuerung mit direkter Durchbruchserfassung";

• "The COROMATIC article" - entitled COROMATIC Microcomputer Control System for Electrostatic Precipitators. This exhibit was accompanied by the minutes of a meeting held on 18 November 1980 between representatives of Lurgi Australia and the Q.E.G.B. at which this system was allegedly discussed;

• Australian Patent No. 535224; and

• European Patent No. 0030321.

Mr Ward acknowledged that, except for the COROMATIC article, these documents were available to the public in Australia before the priority date of the claims in suit. He did not believe there was sufficient proof that the COROMATIC document was published or was in fact the article tabled at the meeting with the Q.E.G.B.. On the other hand Mr Plymin asked me to accept the statements of Mr Shaletzki that this article had been disclosed to the Q.E.G.B., particularly as the applicant had not filed evidence disputing those statements.

I must however agree with Mr Ward's point in relation to the alleged publication of the COROMATIC article. The minutes of the meeting mention only briefly the "Coromatic" control unit and refer to a "prepared paper; reference Frankfurt (M), November 1980" which was the basis for a talk on the "Lurgi Precicontrol process automation system". The COROMATIC article is not mentioned by name and itself does not include the stated reference or any other cross-reference or publication information. Furthermore Mr Shaletzki in paragraph 23 of his declaration states:

"Exhibit WS3 is a true copy of an article entitled COROMATIC Microcomputer Control System for Electrostatic Precipitators which extensively discusses the control system which was discussed with and offered to the Queensland Electricity Generating Board"

He does not state that the content of this article was disclosed to the Q.E.G.B., only that the system was discussed. I am therefore uncertain whether the COROMATIC document was in fact disclosed to the Q.E.G.B and in the absence of any other evidence of publication must disregard this document.

The remaining documents essentially reflect the prior art acknowledged by the applicant in the specification. They disclose controls for electrostatic precipitators that sense DC voltage and current as well as zero-crossing of the AC supply so as to effect control via thyristor control members. Each of the patent specifications also disclose the use of digital processors in the control system. As Mr Ward pointed out, none of the publications disclose the arrangement of the flip-flop circuit and delaying circuit as claimed. While Mr Plymin spoke of anticipation I do not believe that he was disputing this, nor does Mr Shaletzki's statutory declaration suggest disclosure of all the features of the present claim in any of the documents.

Accordingly I find that the present claims are not prior published by the above-mentioned documents in accordance with the test espoused in Flour Oxidising Co. Ltd. v Carr & Co. Ltd 25 RPC 428. Applying the "reverse infringement test", I also find the claims otherwise novel in that the distinguishing features of the flip-flop and delay circuit are clearly essential to the working of the claimed invention.

OBVIOUSNESS

The determination of obviousness depends on the common general knowledge in the field of the invention in Australia, determined at the priority date of the invention, i.e. 28 July 1981 (see the judgement of Aicken J in Minnesota Mining & Manufacturing Co. v Beiersdorf (Australia) Ltd. 144 CLR 253).

At the hearing Mr Ward argued that while Mr Shaletzki could be considered a person skilled in the relevant art his knowledge reflected that of an expert in the field in Germany rather than of the hypothetical non-inventive skilled man in the field in Australia. At the priority date he was not based in Australia and his submissions on what was known in Australia rely only on the fact that between 1979 and 1981 he came to Australia regularly, at least four times a year, selling equipment. There was therefore no evidence of what was the common general knowledge in Australia at the time. Mr Plymin responded by stating that the declarant was skilled in the art in Australia with the declaration indicating that from 1979 to 1981 Mr Shaletzki spent six months of each year in Australia.

From his declaration I believe that Mr Shaletzki is qualified to comment to some extent on the state of the art in Australia at the priority date. In particular he would be aware of the nature of the control systems sold by his and other foreign companies to industry in Australia. However I doubt that Mr Shaletzki's knowledge of the art before the priority date was equivalent to that of the "skilled man in the field in Australia". At that time Mr Shaletzki was still based in Germany, was involved in the development of control systems for electrostatic precipitators and hence had a greater knowledge of the field than that of a skilled man in Australia, where there appears to be no local development of this type of equipment. Thus where Mr Shaletzki states, as in para 19 of his declaration, that prior to the priority date he was aware of certain types of equipment I do not think that the hypothetical skilled addressee in this country would necessarily have had the same knowledge and accordingly I am uncertain whether any of the documents referred to in the declaration were common general knowledge at the appropriate date. Also in this regard Mr Plymin suggested that the prior art acknowledged in the specification should be considered common general knowledge. However I do not believe that this view is justified, particularly in the present circumstances where the specification clearly originated from outside of Australia. There is no reason to depart from the principle that common general knowledge may be positively established only by the evidence of the man skilled in the art in Australia.

Paragraphs 33 and 34 of the statutory declaration, while directed to the claims before amendment, appear central to the question of obviousness in the present case.

"33.In claim 4 of the Application the control device is said to include a flip-flop circuit connecting the third sensing means to the data processing unit. To my knowledge prior to the priority date such flip-flop circuits were used in, for example, the Tarong electrostatic precipitator to connect the sensor of the a.c. power supply to the micro-computer used to process the information.

34.In claim 5 of the Application, a signal delaying circuit is claimed as included in the control device. This circuit is located between the flip-flop circuit and the data processing unit. I do not believe that the incorporation of such circuit is, as at the priority date in Australia, new in conjunction with the use of flip-flop circuits and microcomputer processing units. It was usual to incorporate a delay in causing a pulse to be transmitted to the thyristors to ensure correct timely power impulses"

However, given my doubts as to Mr Shaletzki's qualifications to provide evidence of the state of the art in Australia, I am also unable to conclude that any of the information referred to in these paragraphs was in fact common general knowledge at the priority date. Furthermore, there is no other evidence to support Mr Shaletzki's statements, for example that "It was usual to incorporate a delay in causing a pulse to be transmitted to the thyristors to ensure correct timely power impulses".

As the opponent has failed to clearly establish the common knowledge in the art in Australia at the priority date there is no basis on which a finding of obviousness can be made.

CONCLUSION

I have found that the opposition grounds of lack of novelty, prior publication and obviousness have not been established.  However, the opposition succeeds on the grounds of non-compliance with the requirements of section 40 and I direct the applicant to amend the specification to my satisfaction within 60 days from the date of this decision.

COSTS

Having considered all the circumstances in the present case I do not believe that I should depart from the general principle that costs follow the event. Therefore I award costs against the applicant, FLAKT AB

PHILIP SPANN

Delegate of the Commissioner of Patents

Patent attorneys for the applicant  :  Griffith Hack & Co, Melbourne

Patent attorneys for the opponent   :  Watermark Patent & Trademark Attorneys, Melbourne