Michael Ladney v Battenfeld Australia Pty Limited

[1995] APO 9

official notice

decision of a delegate of the commissioner of patents

Application        :  No. 616913 in the name of MICHAEL LADNEY

Subject:  Injection moulding

Action: S.59 opposition under the 1952 Act by BATTENFELD AUSTRALIA PTY LTD

Decision:  Issued            .

Abstract:  Opposition established, claim 1 not novel, invention not fully described, opportunity given for applicant to propose amendments. Inconsistencies between specification and evidence in determining essential features.

patents act 1990

decision of a delegate of the commissioner of patents

Re:Patent Application No. 616913 by MICHAEL LADNEY and opposition under S.59 of the Patents Act 1952 by BATTENFELD AUSTRALIA PTY LIMITED.

background

Convention application 616913, for a patent for an invention relating to injection moulding, comprises a complete specification filed on 4 November 1988, with priority claimed from application 121908 filed in the United States on 17 November 1987.  The applicant named in the originally filed documents was James W. Hendry, but after action under S.113 of the 1990 Act, the application continued in Mr Ladney's name. The Convention application was advertised accepted on 14 November 1991 and opposed on 10 March 1992.  As the application was filed before, but accepted after, the commencement of the Patents Act 1990, Section 59 of the Patents Act 1952 applies to the opposition, but Chapter 5 of the Patent Regulations 1991 applies in relation to the opposition proceedings.

After the opponent's evidence-in-support was filed, the applicant proposed amendments to the specification under S.104 of the 1990 Act; these were allowed on 11 June 1993.  However, the opposition was maintained, the parties served their evidence-in-answer and evidence-in-reply, and the matter was heard in Canberra on 28 November 1994. The applicant was represented at the hearing by Mr Brian Munday, patent attorney, and the opponent was represented by Mr Craig Vinall, patent attorney.

the specification

The specification indicates that the invention relates to a process for injection moulding where a gas is injected under high pressure into a molten plastic stream as it enters a mould sprue and a mould space.  The gas assists the filling of narrow or elongated mould spaces with molten plastic.  The molten plastic is usually injected at high pressure, so the gas must also be injected at high pressure and over a short time period.  The specification indicates that conventional apparatus which has attempted to simultaneously inject pressurized molten plastic and gas has not been satisfactory because the gas pressurizing equipment has been too slow to build up the necessary pressure at exactly the right time in the process.  This has resulted in "shadow marks" being formed on the surface of the moulded articles.  The invention solves this problem by using a two-way directional high pressure air valve to control the flow of gas from a high pressure gas storage tank at the appropriate time.  The valve is opened after a time delay just sufficient to permit the molten plastic to fill the mould sprue.

The specification, as amended under S.104, contains 18 claims defining the invention; only the broadest claim, claim 1, was considered in detail at the hearing; it reads as follows:

"1.A process for producing an injected moulded product comprising:

supplying a plastics material;

introducing a molten stream of the plastics material into a mold space at a first pressure;

introducing a gas into said molten stream of plastics material immediately after said molten material has passed a position at which the gas is introduced thereby forming a gas cavity in the molten material, the gas being introduced at a second pressure, the gas in said gas cavity exerting pressure on the surrounding plastics material to urge the material toward a surface of said mold space;

continuing to feed plastics material to said mold space;

simultaneously continuing to inject gas into the said gas cavity;

terminating the supply of molten material;

terminating the supply of gas;

subsequently maintaining a pressure within the gas cavity as the plastics material cools and solidifies; and,

venting the gas from said gas cavity at a controlled rate."

grounds of opposition; the evidence

The opponent's statement of grounds and particulars alleges that the invention was obtained, that the claims of the specification should not have Convention priority, that the specification does not comply with S.40 of the Act, and that the claims are obvious and not novel.  However, at the hearing only the grounds of novelty and obviousness were pursued in-depth.

The evidence-in-support includes 7 declarations; some of the more relevant are as follows:

.   Colin William Dibbs, dated 29 June 1992. Mr Dibbs, Principal Technical Service Officer with ICI's Plastics Technical Centre, refers to British patent application 2139548, published in 1984. (The British applicant is James W. Hendry, the original applicant for the present Australian Application 616913). Mr Dibbs declares, inter alia:

"That in October 1987 the Plastics Institute of Australia conducted an "AUSPLAS" exposition in Melbourne, and at the time of that exposition a "CINPRES" gas injection attachment was demonstrated to large numbers of people who attended the exposition. The equipment used was substantially in accordance with Figure 5 of the British patent specification GB 2139548..."

.   Kerry William Henderson, dated 25 June 1992. Mr Henderson, Managing Director of Plas-Tec Pty Ltd, a South Australian injection moulding company, declares, inter alia, that he expressed interest in the CINPRES equipment to ICI in May 1987; and that a proposed sub-licence was in respect of the subject matter described in GB 2139548.  He also declares that later the CINPRES order was cancelled and that he chose the present opponent Battenfeld's "AIRMOULD" equipment instead.

.   Clive James Dawber, dated 25 June 1992. Mr Dawber, a technician in the plastics industry since 1977 and an employee of Battenfeld, Australia, refers mainly to the AIRMOULD process and equipment; but he also refers in paragraph 9 to "the well established and used CINPRES process". 

.   Richard Kenneth Maddern, dated 26 June 1992.  Mr Maddern, a patent attorney and electrical engineer, refers to several Australian, British and United States patents which he alleges either disclose the present invention or give an overview of the state of the art. Of particular interest are two US patents  published in 1978: 4,129,635 to Yasuike, and 4,101,617 to Friederich, both of which disclose a "simultaneous injection" process similar to that described in the present application.

A considerable amount of the opponent's evidence related to its AIRMOULD process (Mr Henderson indicates that it is Battenfeld's "equivalent to CINPRES"). However, there are conflicting parts in this evidence relating to the dates when documents describing the process were published in Australia and when the process was first used in Australia. I therefore consider this evidence to be of low probative value.

The evidence-in-answer consists of a declaration by Mr Munday, dated 20 August 1993.  Attached thereto is a copy of the judgement and portion of the transcript of a trial in the United States involving the abovesaid James W. Hendry, the present inventor, Indra Baxi, and the US basic application.  The transcript of a cross-examination of Mr Baxi on the subject of the last step in the process of present claim 1, ie. "venting the gas from said gas cavity at a controlled rate", suggests that there may be some advantages associated with using a metering valve for this part of the process.

The evidence-in-reply includes three declarations:

.   Murray Amos, dated 3 March 1994.  Mr Amos declares that he is the proprietor of a business specialising in the sale and distribution of pneumatic control equipment, that pressure reducing valves, metering valves and the like are well known, and that it would be obvious to use such valves when it was recognised that the flow rate of a vented gas was excessive.
.   Helmut Eckardt, dated 18 February 1994.  Mr Eckardt is an injection moulding specialist employed by Battenfeld GmbH in Germany. He has considerable experience in the art, mainly in Germany, but he declares that he has travelled to Australia on numerous occasions and that he is familiar with the state of the art in Australia.  He declares, inter alia:

That the CINPRES process which is described in GB 2139548  and AU 27893/84 was "commonly known and used prior to November 1987 both internationally and in Australia".

That it was a recognised common problem with the CINPRES and other known processes that a sudden release of pressure could cause molten plastic to be blown back through either the sprue of the moulded component or air passages within the nozzle, thus leading to blockages and bubbles.

That numerous solutions to these problems had been used before November 1987 in Australia, eg:

.holding the product in the mould cavity for a longer period of time,

.slowly retracting the injection nozzle to restrict the venting orifice,

.restricting the diameter of the sprue or the injection gate to provide a smaller orifice, or

.allowing the pressure to vent through the air passages and valves of the injection gas line, the resistance thus slowing the pressure release

In paragraphs 5 and 6 of his declaration, Mr Eckardt refers particularly to venting methods used in the CINPRES process, viz:

"Prior to November 1987....it was and still is common practice on CINPRES equipment both internationally and in Australia to effect a control of the venting rate by only slightly withdrawing the injection nozzle....or by controlling the retraction rate of the piston pumps."

"In particular the CINPRES process as described in British patent specification 2139548 shows a staged pressure reduction which results from withdrawal of a piston-type pump. In particular at page 3 lines 14-20 the specification describes pressure reduction by withdrawal of a piston so that the pressure is reduced from 400 psi to 200 psi. The rate at which this pressure reduction occurs is controlled by the rate of withdrawal of the piston which in itself is controlled by the associated hydraulic equipment. Under normal operating speeds the rate at which the piston is withdrawn provides a slower rate of pressure reduction by comparison to withdrawal [sic] of the injection nozzle, and therefore in some instances alleviates the problem associated with molten plastic blow-back. In my opinion, the system described in British patent specification [sic] in itself is a form of controlled venting rate."

.   A second declaration from Mr Henderson, dated 21 February 1994.  Mr Henderson refers to Mr Eckardt's declaration, he agrees with all of the points raised by Mr Eckardt, and he attests to Mr Eckardt's standing and expertise in the art.

submissions

Mr Vinall's submissions at the hearing are summarized as follows:

.   The step of "venting the gas...at a controlled rate" in claim 1 is not an essential feature because it does not contribute to the working of the invention. 

.   A skilled addressee would interpret the scope of the specification to include the known technique of releasing the gas pressure by retraction of the injection nozzle in a manner that would not cause damage to the moulded component; ie. at a controlled rate.

.   The claims are anticipated and lack novelty in the light of the cited prior art.

.   The CINPRES and AIRMOULD equipment was demonstrated at a national industry exhibition in October 1987, and therefore the information made available at the exhibition should be regarded as common general knowledge at the priority date of the present application.

.   The technique of slowly releasing gas pressure by slowly withdrawing the injection nozzle to prevent melt blow back, and the use of pressure reducing and metering valves were also matters of common general knowledge.

.   Taking into account the problem to be solved and the common general knowledge, a non-inventive worker in the trade would have arrived at the claimed invention as a matter of routine without the exercise of any invention. The claims are therefore obvious.

.   The present specification is deficient because it is "silent on the supposed essential feature" referred to in the applicant's submissions. For example, no values have been given for controlled pressure rates.

.   The evidence-in-answer carries little weight because the parts of the transcript attached to Mr Munday's declaration may be taken out of context; eg. what did Baxi say in the rest of the evidence? Did he retract or revise his comments?

Mr Munday's submissions at the hearing are summarized as follows:

.   The invention is characterized by the controlled rate of venting step and it is therefore an essential feature.

.   The cited prior art does not include this essential feature therefore the claims are novel.

.   There are inconsistencies in the opponent's evidence with regard to when the AIRMOULD process was first made public in Australia.

.   The evidence-in-answer demonstrates the importance of the controlled venting feature; a previously-used check valve was removed and a metering valve used instead.

.   The citations, eg. GB 2130548, do not show the use of a metering valve to vent the gas from the mould cavity. A metering valve is not a mechanical equivalent of the prior art valve arrangements.

.   The patent applicant objects to the evidence-in-reply because it does not relate to the evidence-in-answer.

.   Eckardt was not resident in Australia so there is some doubt as to his knowledge of when the CINPRES process was made available in Australia. Also, Mr Henderson has no corroborating evidence that CINPRES was used prior to November 1987.

.   The opponent's own patent, No.616429 (copy attached to Mr Dawber's declaration) at lines 24-27 on page 7, indicates that it is preferable for a check valve to be placed in the gas pipeline to the injector head so that reversal of the gas flow is prevented. This leads away from the solution to the problem in the present invention. The present applicant realized that there were advantages in using a metering valve to control the venting.

.   The specification is not deficient; it is not necessary to specify venting pressure rates since these will vary considerably in practice depending, inter alia, on the materials used in the moulding process.

decision

I shall first consider the issue of whether the feature in claim 1 of "venting the gas from said gas cavity at a controlled rate" is an essential or inessential feature of the claim.

It is clear from the judgements in Catnic Components v Hill & Smith Ltd (1982) RPC 183 at 228 and in Rodi and Wienenberger v Henry Showell Ltd (1969) RPC 367, that the fact that a claim incorporates a particular feature does not alone suffice to make that feature an essential one. If this were not so, no feature in a claim could ever be inessential. Thus it is necessary to refer to the description of the invention to determine this matter.

As previously discussed, the specification suggests that the object of the invention is to overcome problems associated with the slow response time of conventional piston and cylinder pumps for pressurizing gas for injection into the molten stream of plastic. The specification indicates that the invention allows gas to enter the molten stream of plastic immediately after the stream has passed the position at which the gas is introduced, to form the gas cavity as soon as possible.  This is achieved, inter alia, by using a high-pressure gas storage tank and an associated control valve arrangement. The specification does not associate this problem to be overcome and the object of the invention with  the step of controlled venting. Also, at the hearing Mr Munday referred to the problem to be overcome as the "blow-back" which occurs when the pressure is reduced too quickly; but this is not the problem referred to in the specification.

The "abstract of the disclosure" in the specification, on the venting aspect of the invention, merely states: "A pressure is held within the gas cavity as the plastic material cools. Subsequently, the pressure is released to bring the gas cavity to ambient pressure." 

The controlled rate of venting is referred to on page 14 of the specification, but merely as an alternative to a one-step venting procedure, viz:

"...valve 30 is not opened until the mould 11 has cooled sufficiently to be self-supporting. At such time, the valve 30, which may be a two-way directional valve, is activated to the open position by air valve cylinder 24 to vent the pressurized gas from the system and bring the moulded part B down to atmospheric pressure. If desired, however, the valve 30 can be a metering valve to control the rate of exhaust."

There is no emphasis placed on this controlled venting feature in the specification as a whole (see Sebel Properties v Fagaleo Pty Ltd 14 IPR 524), the feature does not materially affect the way the invention works (see Catnic v Hill, supra, and Ryan v Lum (1989) 14 IPR 513) and the specification does not refer to any advantages associated with the feature (see Rodi v Showell, supra).  Therefore, in my opinion, an addressee construing the specification would not see controlled venting as an essential feature of the invention as claimed. 

However, I have other material before me which is relevant to this matter. In Van Der Lely v Bamfords [1963] RPC 61, Lord Reid, although dissenting, suggested that, in trying to determine whether a feature of a claim was essential or otherwise, one should look at all the facts of the case, not just the specification. I think this is a sensible approach.

Taking into account Mr Baxi's comments in the US court transcript, Mr Munday's submissions at the hearing and the applicants attorneys' comments in correspondence with the examiner during the examination of the application, I think it can be concluded that the controlled venting feature is an essential feature of claim 1.

Thus I am confronted with a situation where the specification is inconsistent with other facts before me. The addressee of a patent specification only has that specification to determine what the invention is; he or she should not have to refer to a transcript of some court action or the like to discover the true nature of the invention. The present invention appears to be an improvement in similar existing injection moulding processes with the improvement residing in the manner in which the gas is vented from the cavity.  However, this improvement is not apparent from reading the specification, which is thus misleading the addressee. Consequently, I am led to conclude that the invention has not been fully described and the specification does not comply with S.40(1)(a) of the 1952 Act.  See May v Higgins (1915) 21 CLR 119 and Sami S. Svendsen Inc v Independent Products Canada Ltd (1969) AOJP 647. Kitto J. in the latter case stated:

"Assuming that there was an inventive step in this improvement, I am of opinion, first, that the specification as a whole offends against s.40(1) by not describing the invention, since it does not enable the reader to discern what was the invention in the total thing that it describes; and, secondly, that the claims themselves offend against s.40(1) by defining as the invention something that was much more extensive than the invention ...

This is a ground upon which, in the public interest even if not for any other reason, the Deputy Commissioner could, and in my opinion should, have upheld the objections and refused to grant a patent upon the specification in its present form ...

I do not mean that in every case of opposition it is a function of the Commissioner to investigate for himself the question how the actual invention compares with the invention as claimed.  What I have said is based upon the circumstance that the evidence of Mr Flomen, one of the actual inventors, contains clear admissions, indeed positive assertions, of facts which leave no room for doubt that the specification both in its description and in its claims disobeys s.40(1).  The nature of the disobedience is such that the specification is likely to mislead, and for that reason the application ought to be refused ..."

The applicant objected that the evidence-in-reply was not properly in-reply to the evidence-in-answer. I do not agree with this objection: the three declarations in the evidence-in-reply are mainly directed to the controlled venting feature; and this is appropriate since, firstly, this feature was not given any emphasis in the specification, and secondly, the US court transcript in the evidence-in-answer suggested that the said feature was of considerable importance.

In the matter of novelty, I think the cited British specification 2139548 is pertinent. Firstly, there was some discussion at the hearing of the differences between the CINPRES process, as described in the cited specification, and the present invention; one being that in the former a fixed volume of gas is used whereas in the latter the constant applied pressure was more significant than the volume of gas.  On this point I note that present claim 1 has a feature of "subsequently maintaining a pressure within the gas cavity as the plastics material cools and solidifies.."; however, this feature does not exclude what is described in the citation, viz. at column 2 line 113 to column 3 line 3:

"The end of the stroke of piston 20 of the ram 39 may be timed to substantially coincide with the completion of the filling of the mould space 12 with plastics material 8, ie. the end of the stroke of the screw ram 13. Alternatively, when the screw ram 13 has travelled its full stroke, the piston 20 may have some forward movement remaining, which is completed after the end of the introduction of plastics material. The result is that the nitrogen continues to be injected into the mass 38 formed within the plastics material after the mould space is full, whereby the pressure of the nitrogen in the mass 38 is increased and thereby the outward pressure applied on the plastics material urging it towards the mould surfaces to improve the plastics surface definition.
   Both rams 13, 39 remain in their full operative positions until the moulded part and the sprue have cooled and their surface skin is self supporting."

Another difference between the citation and the present invention is the use of a metering valve in the latter, but I note that this is not a feature of claim 1.

Secondly, on the matter of whether the citation discloses the controlled venting feature, I am influenced by Mr Eckardt's construction of the citation, referred to earlier, and I agree that the part cited can be construed as "venting the gas at a controlled rate".  The relevant part of the cited specification is on column 3, lines 9-20 viz:

"On completion of the return movement of the piston 20, valve 22 is closed. The pressure of the nitrogen trapped in the cylinder 21, and also the pressure of the gas still downstream of the valve 22, both in the passageway 19 and the mass 38, has thereby halved compared with the previous pressure, ie. if the pressure was 400 psi it is now 200 psi. Valve 27 is then opened which relieves the remaining pressure of the nitrogen in the moulded part to the desired level which may be atmospheric pressure or above."

Mr Eckardt is clearly an expert in the art and is therefore a proper skilled addressee of the citation.  Also, apart from Mr Munday's submissions, the applicant has adduced no evidence contradicting Mr Eckardt's evidence. Furthermore, I see no reason for me to place a narrow interpretation on the expression "controlled rate"; there is no definition, elaboration or examples of this expression in the specification, so I think it is appropriate to interpret it in its normal sense. To "control" is simply to check or restrain some action, and in the cited specification the two-step venting process described is clearly a more restrained action than simply allowing the pressure to drop immediately to atmospheric, by withdrawing the nozzle for example. (See Freeman v Pohlner Fed. Ct. SA No.SG65 of 1994).

Thus I conclude that claim 1 is anticipated by and is not novel in the light of GB 2139548.

Claim 1 is not anticipated by the US patents to Yasuike and Friederich because those citations disclose venting by simply separating the nozzle from the mould, ie. they do not disclose any feature which can be construed as "venting the gas from [the] gas cavity at a controlled rate", which I have decided is an essential feature of claim 1.

In the matter of obviousness, I think the balance of evidence suggests that the CINPRES process was common general knowledge in Australia at the priority date of the claims of the present specification. It was agreed at the hearing for example that Mr Henderson was an independent party, and it seems as though he, and others, were aware of the state of the art at that time. However, the CINPRES process is described in GB 2139548, and since I have found claim 1 to be anticipated by that British specification, it seems unnecessary for me to decide whether the claim is obvious in the light of the same.

conclusion

I have found the opposition to application No.616913 has been successful because claim 1 is not novel and the specification does not comply with S.40. However, I think there may be patentable subject-matter in the specification and thus I allow Michael Ladney 60 days from the date of this decision to propose amendments to overcome the objections to the specification.

In the matter of costs I follow the usual practice of costs following the event and I award costs against Michael Ladney.

John Welsh
Delegate of the Commissioner of Patents

Patent attorneys for the applicant  :  Spruson & Ferguson, Sydney

Patent attorneys for the opponent   :  R K Maddern & Assoc, Adelaide