David Richard Collis v the Water Board and the State of New South Wales as Represented by the Public Works Department

[1990] APO 9

In the Matter of the Patents Act 1952

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In the Matter of Petty Patent No. 580543 in the Name of DAVID RICHARD COLLIS

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In the Matter of an Application under Sub‑Section 68B(1) for an Extension of the Term of the Petty Patent and a Notice under Sub‑Section 68B(3) by THE WATER BOARD and THE STATE OF NEW SOUTH WALES as Represented by the PUBLIC WORKS DEPARTMENT.

DECISION OF A DELEGATE OF THE COMMISSIONER OF PATENTS:
Background
         Application No. 19766/88 was lodged on 25 July 1988 by David Richard Collis for a petty patent for an invention relating to scouring of pipes and hoses.  Petty patent No. 580543 was sealed on the application on 30 January 1989; on 23 November 1989 the patentee applied for an extension of term and on 13 December 1989 The Water Board and the State of New South Wales as represented by the Public Works Department (hereinafter referred to as the objectors) lodged notice under sub‑section 68B(3) informing the Commissioner of facts which allegedly established that the invention was obvious and did not involve an inventive step and that the invention was not novel.

The matter came to hearing in Canberra on 19 February 1990; the patentee was not represented and the objectors were represented by Mr Graham Halford, patent attorney.
The Specification
         The specification indicates that the invention relates to methods and apparatus for scouring or cleaning liquid‑carrying pipes and hoses, particularly water mains.  The prior art involved the use of methods such as full‑flow liquid flushing or high‑pressure air flushing and use of apparatus such as push‑rod and pull‑wire cleaning devices or driven cleaning devices called "pigs".
         The invention allegedly avoids the disadvantages of the prior art and is based on the discovery that effective cleaning can be achieved if a gas, typically air, is injected into liquid flowing through the pipe so that plugs of liquid are driven along the pipe by entrapped pockets of compressed gas.  The claim defining the invention is as follows:

"A method of scouring a section of a pipe or hose in which fluid flow may be constricted by sedimentation or encrustation, comprising the steps of:

*admitting liquid under pressure to one end of the section via a valve which can be adjusted to vary the flow of liquid into the section, and allowing the liquid to flow through the section and to freely discharge from the other end thereof,

*injecting a gas into the section at or near said one end thereof downstream of said valve at a pressure which is less than that of the liquid on the upstream side of the valve, and

*adjusting the flow of the liquid and/or the gas to cause a pulsatory flow of plugs of liquid separated by gas pockets to emerge from said other end of the pipe or hose section."

The description further indicates that:

(i)the injected air pressure is typically 50 kilo Pascals below the water mains pressure,

(ii)the pulsing can be achieved by adjustment of the rates of flow of the water and injected air in the section to be cleaned; for example the water flow adjusting valve was set at 25% capacity for an air flow rate of 200 litres/sec,

(iii)the pulsing can alternatively be achieved by the use of a pulsing valve in the air line near the point at which air is injected into the pipe; use of a pulsing valve is quicker than the adjustment method described above especially when the invention is used with pipes of widely varying diameters or with pipes which have a significant slope.

The Evidence
         The evidence lodged under sub‑section 68B(3) consists of a declaration by Peter Leonard Burgess, a civil engineer employed by the Water Board since 1966.  Mr Burgess refers to a technical report by the Water Research Centre in the United Kingdom.  The report, TR179, is entitled "Air Scouring of Water Mains ‑ A Method of Operation" and is dated April 1982.  Subsequent evidence lodged by the objectors (which I have considered under sub‑sections 68B(5) and (6) shows that this report was open to the public in the Water Reference Library, Water Research Laboratory, University of New South Wales, prior to the priority date of 25 July 1988.
         Report TR179 is directed to similar subject‑matter to that of the present invention.  The air scouring method described in the report includes the feature of slug flow; in the second‑last paragraph on page 7 it is stated:

"... given a continuous supply of water and air, discrete slugs of water are formed in the main and driven along by the air.  There is no need to turn the water or air on and off to achieve this effect."

Pertinent diagrams are shown on page 8 of the report.  On page 12 reference is made to an air pressure regulator in an air injection system, the regulator being set at 0.5 bars [50 kPa] below the water mains static pressure to prevent air travelling backwards along the main.  On pages 25 and 26 a detailed description is given of how air injection apparatus and other apparatus associated with the water main are controlled and adjusted to achieve slug flow through the section of main being scoured.  Clear reference is made to careful adjustment of a line valve to achieve the desired effects.
         At the hearing Mr Halford submitted that the claim of the petty patent was wholly anticipated by report TR179 and that therefore it was unnecessary for the objectors to pursue the ground of obviousness as stated on the sub‑section 68B(3) notice.
Decision
         I find that the claim of petty patent No. 580543 is anticipated by and not novel in the light of report TR179.  However I am presently inclined not to refuse to extend the term of the petty patent since I cannot say for certain that there is no patentable subject matter disclosed in the specification.  (I note in this regard that page 8 and figure 2 of the petty patent specification refer to, in some detail, a pulsing valve suitable for use in the invention.)  Consequently I allow the patentee 60 days from the date of this decision to propose amendments to cause the specification to claim patentable subject matter.
         I award costs against the patentee.

(J.I. WELSH)

Patent attorneys for the patentee : P. Grant & Associates