E Street Enterprises Inc v CPS Housewares Pty Ltd [1995] FCA 751

IN THE FEDERAL COURT OF AUSTRALIA) ) NEW SOUTH WALES DISTRICT REGISTRY) No. G126 of 1994 ) GENERAL DIVISION ) BETWEEN: E STREET ENTERPRISES INC Applicant/Cross Respondent AND: CPS HOUSEWARES PTY LIMITED Respondent/Cross Claimant

20 September 1995 REASONS FOR JUDGMENT LOCKHART J. E Street Enterprises Inc (E Street) sues CPS Housewares Pty Limited (CPS) for alleged infringement of claims 1 and 2 of Australian Patent No 585736 (the patent) of which E Street is the registered proprietor. The complete specification is for an invention entitled "pump closure for carbonated beverage container". The priority date is 12 November 1986, being the date of the United States convention application. E Street is a United States corporation and CPS is incorporated in New South Wales. E Street alleges that CPS has infringed the two claims by importing, selling and offering for sale pump closures for carbonated beverage containers. The allegedly infringing closure is known as the "Fizz Keep". E Street alleged initially that CPS had infringed E Street's rights as patentee by importing, selling and offering for sale another pump closure known as the "Phizzkep Pressurizer", but this allegation was abandoned at the commencement of the hearing. CPS denies infringement; and by its defence and cross-claim asserts that the patent is invalid on the grounds of (a) obviousness; (b) want of novelty at the priority date by reason of prior publication of various patents in the United States, the United Kingdom, France and Australia; and (c) want of novelty in the light of the availability in Australia before the priority date of a camp stove known as the Optimus Model IIIB. CPS seeks revocation of the patent on these grounds. On the issue of infringement, CPS admits that it imports, sells and offers for sale the Fizz Keep device; but it says that the device does not involve all the integers claimed in claims 1 and 2 of the patent. The invention is a pump closure for carbonated beverage containers and in particular for a screw cap closure, having a pump to pressurize a beverage container with ambient air, the purpose of which is to reseal the container and maintain the contents under pressure until the container is opened again to dispense the beverage. Carbonated beverages typically contain dissolved carbon dioxide gas which will escape into the atmosphere unless the container is pressurized and sealed. The flavour of such carbonated beverages turns flat in the absence of the dissolved carbon dioxide gas. The purpose of the closure is to reduce the loss of carbonation, and also of flavour, by sealing the beverage container after use. The statement of the invention in the complete specification, so far as material, is in these terms: "PUMP CLOSURE FOR CARBONATED BEVERAGE CONTAINER This invention relates generally to closures for beverage containers, and in particular to a screw cap closure having a pump for pressurizing a beverage container with ambient air. Carbonated beverages are sold in glass and plastic containers which are pressurized and then sealed by original factory closures. The purpose of the closure is to seal the container and maintain the contents under pressure until the container is opened for dispensing the beverage. Some beverage containers are relatively small, in the six-to-ten-ounce range, and are sealed by a disposable cap which is discarded after the beverage container is opened. Larger beverage containers, for example in the two-to-three-litre range, are provided with a reusable screw cap closure for resealing the container after a portion of the beverage has been served. Carbonated beverages typically contain dissolved carbon dioxide gas which will escape into the atmosphere unless the container is pressurized and sealed. The flavor of such carbonated beverages turns flat in the absence of the dissolved carbon dioxide gas. The loss of carbonation can be reduced somewhat by sealing the beverage container after use. However, because of the relatively large volume of some beverage containers, the carbonization will be released into the sealed open space within the container, with the result that the flavor of the remaining beverage is impaired. Accordingly, the quality of the beverage in such larger containers will gradually deteriorate, with the result that a substantial portion of the beverage will become unpalatable, and will be discarded. The practice of sealing the open volume within the beverage container to reduce the rate of loss of carbonation from the beverage is commonly accepted. Closure devices having a resilient sealing member for insertion into and engaging the neck of the container have provided a secure seal for the interior volume of the container. However, as the amount of beverage remaining is reduced, the open space grows larger, and more and more of the dissolved carbonation is released from the beverage and into the open space. It has also been recognized and demonstrated that if the open volume within the beverage container is repressurized with ambient air, the amount of dissolved carbon dioxide released from the beverage will be substantially reduced. Pumping devices have been proposed for pressurizing the open volume within the container with ambient air. It is also known to combine a closure cap and pressurizing pump for insertion into the neck of a beverage container. Such prior art pressurizing and closure devices have failed in some instances to develop and maintain the pressure within the open volume of the beverage container at a level greater than the pressure of dissolved gases within the beverage. In some instances, such pump closure devices have been unable to develop a sufficiently high enough pressure within the container open space because of leakage through or around the sealing components of the pump. In other instances, the prior art pumping devices have developed adequate pressure levels initially, but were unable to maintain the interior pressure at the desired level because of leakage." The consistory clause follows in the same terms as claim 1 in the patent. The specification then proceeds in these terms:- "According to an important feature of the invention, the pump cylinder is provided with an improved check valve assembly in which an outlet port is sealed by a resilient, conformable member which engages a tapered sealing surface formed within the cylinder sidewall in an area which is coincident with the outlet port. As a result of resilient flexure of the sealing member against the tapered sealing surface, the forces directed onto the sealing member during an up-stroke operation and at rest are uniformly distributed across the face of the member, thereby avoiding the creation of wrinkles which could compromise the seal. Moreover, during a down-stroke operation in which air is forced out of the compression chamber and into the open space of the beverage container, the resilient member is easily displaced away from the tapered surface surrounding the discharge port to permit the container open space to be pressurized. According to another aspect of the invention, the annular seal is received about a reduced diameter portion of the piston, and is axially movable along the reduced diameter portion to a first position in which a vent groove formed on the piston is open for the admission of air from the air supply annulus into the compression chamber during up-stroke retraction of the piston. The annular seal is axially movable along the reduced diameter portion from the first position to a second position in which the seal engages the piston and seals the air supply annulus with respect to the vent groove as the piston and seal move through the pump cylinder during down-stroke movement, thereby permitting high compression levels to be established." This is followed by a detailed description of the invention with reference to five attached drawings (figures 1 to 5). Five claims are made defining the invention. Only claims 1 and 2 are said to be infringed. They are in the following terms: "1. A pressurizing and closure assembly for use in combination with a carbonated beverage container comprising: a closure cap having a central opening; a pump having a pump housing attached to said closure cap, said pump housing having a cylindrical bore aligned with said central opening and a piston mounted for reciprocal movement through said bore, said piston having a reduced diameter portion and a vent groove formed on said reduced diameter portion; a seal mounted on said reduced diameter piston portion for axial displacement from a first position to a second position along said reduced diameter portion, said seal defining the boundary of a compression chamber within said bore on one side of the seal, and an air supply annulus being defined between the piston and the pump cylinder bore on the other side of the seal, said seal having a resilient, annular shoulder engaging said piston bore and said piston and sealing the air supply annulus with respect to said vent groove when said seal is in the first position, and said seal being movable to the second position on said reduced diameter piston portion wherein said vent groove is in communication with the air supply annulus and the compression chamber; and,