Patents

Case Note: Hewlett Packard GmbH and Another v Waters Corporation and Another

Jane Lambert

21 June 2004
This was the trial of an application to revoke, and of a separate action for the infringement of, a European patent for pumping apparatus for delivering liquid at high pressure. Revocation was sought on grounds of anticipation and obviousness. The judgment illustrates the application of the well-known principles set out in Improver v Remington [1990] FSR 181, General Tire v Firestone [1972] RPC 457 and Windsurfing v Tabur Marine [1985] RPC 59.

The Patent
The patent in suit was concerned with a pump suitable for use in a particular analytical technique used in chemistry called high performance liquid chromatography whereby a sample of material to be analysed is dissolved, injected into a stream of solvent and passed over the contents of a column called a separation column. The technique works on the principle that different compounds adhere to material in a column to different degrees so that they are washed down at different rates. The composition of an unknown sample can therefore be determined by timing the arrival of each component at the end of the column. It therefore requires pumps that can provide smooth flows of solvent through the column. The principal feature of the invention was an adjustable stroke volume enabling flows to be increased without altering the pumping rate. The alleged infringement also permitted variation of solvent flows to increase without altering the pumping rates but it did so in steps rather than lineally. The invention was alleged to have been anticipated in an American specification for a 2-stage pump for use in high performance liquid chromatography.

The Trial

Applying the Improver test, Pumfrey J found that the variant did have a material effect on the way that the invention worked, that such and therefore that it did not infringe. On the other hand, nothing in the US specification required stroke rate to be altered with the flow rate so there was no question of anticipation. Indeed, there was no general teaching whatsoever as to the association of a variable swept volume with flow rate. It was therefore anticipation or nothing and, as the attack for want of novelty had failed, the judge found the patent to be valid. Both parties appealed to the Court of Appeal.

Infringement

The patentee complained that the trial judge had unnecessarily imported language into the principal claim that limited its scope. The Court of Appeal agreed. When read with the specification as a whole, the characterizing part of that claim required a control means to be coupled to both pistons for adjustment but there was no requirement that both pistons have to be adjusted at every increment of flow change. The variant did fall within the scope of that claim in that its control means adjusted the stroke volumes of its pistons in response to the desired flow rate. It followed that it did infringe.

Anticipation
The Court of Appeal upheld the trial judge's finding on validity. On anticipation, the Court referred to its judgment in General Tire & Rubber Co. Ltd v Firestone Tyre & Rubber Co. Ltd [1972] RPC 457, 458:

“When the prior inventor’s publication and the patentee’s claim have respectively been construed by the court in the light of all properly admissible evidence as to technical matters, the meaning of words and expressions used in the art and so forth, the question whether the patentee’s claim is new for the purposes of section 32(1)(e) falls to be decided as a question of fact. If the prior inventor’s publication contains a clear description of, or clear instructions to do or make, something that would infringe the patentee’s claim if carried out after the grant of the patentee’s patent, the patentee’s claim will have been shown to lack the necessary novelty, that is to say, it will have been anticipated. The prior inventor, however, and the patentee may have approached the same device from different starting points and may for this reason, or it may be for other reasons, have so described their devices that it cannot be immediately discerned from a reading of the language which they have respectively used that they have discovered in truth the same device; but if carrying out the directions contained in the prior inventor’s publication will inevitably result in something being made or done which, if the patentee’s patent were valid, would constitute an infringement of the patentee’s claim, this circumstance demonstrates that the patentee’s claim has in fact been anticipated.

If on the other hand, the prior publication contains a direction which is capable of being carried out in a manner which would infringe the patentee’s claim, but would be at least as likely to be carried out in a way which would not do so, the patentee’s claim will not have been anticipated, although it may fail on the ground of obviousness. To anticipate the patentee’s claim the prior publication must contain clear and unmistakable directions to do what the patentee claims to have invented: Flour Oxidizing Co. Ltd v. Carr & Co Ltd. ((1908) 25 RPC 428 at 457 line 34, approved in BTH Co. Ltd v Metropolitan Vickers Electrical Co. Ltd (1928) 45 RPC 1 at 24, line 1). A signpost, however clear, upon the road to the patentee’s invention will not suffice. The prior inventor must be clearly shown to have planted his flag at the precise destination before the patentee.”

The closest prior art disclosed all but one of the features of the claimed invention but in the absence of evidence that the inevitable result of the other features being present would operate in accordance with the claim it could not be established that there were clear and unmistakable directions. It followed that the attack on grounds of anticipation failed.

Obviousness

So, too, did the attack on grounds of obviousness. Going straight to the third of the Windsurfer questions, the Court found a real difference between the invention and closest prior art which could not be described as obvious.

Order

The Court therefore allowed the patentee's appeal on infringement and dismissed the appeal on validity. It granted an injunction to the patentee which was suspended pending a petition for permission to appeal to the House of Lords.