Neutral Citation Number: [2017] EWCA Civ 2175

Case No: A3 2016 0241

IN THE COURT OF APPEAL (CIVIL DIVISION)

ON APPEAL FROM THE HIGH COURT OF JUSTICE

CHANCERY DIVISION

PATENTS COURT

Mr Justice Mann

[2015] EWHC 3163 (Pat)

Royal Courts of Justice

Strand, London, WC2A 2LL

Date: 19/12/2017

Before :

LORD JUSTICE KITCHIN

and

LORD JUSTICE FLOYD

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Between :

Saab Seaeye Limited / Appellant
- and -
(1) Atlas Elektronik GmbH
(2) ECS Special Projects Limited / Respondents

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James Mellor QC (instructed by Norton Rose Fulbright LLP) for the Appellant

Iain Purvis QC and Tom Alkin (instructed by EMW Law LLP) for the Respondents

Hearing date: 29 November 2017

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Approved Judgment

Judgment Approved by the court for handing down. / Saab Seaeye v Atlas and another

Lord Justice Floyd:

Judgment Approved by the court for handing down. / Saab Seaeye v Atlas and another

1.  This appeal raises some short points in relation to patents in the field of underwater mine clearance. The first and second defendants (to whom I will refer compendiously as “Atlas”) are the respective owners of two patents relating to mine clearance devices, namely UK Patent Nos 2 482 576 and 2 483 861. For convenience I will refer to these patents using their last three digits, “576” and “861”. The claimant (“Saab”) brought these proceedings to seek revocation of those patents, and the defendants counterclaimed for infringement. In a judgment dated 4 November 2015 ([2015] EWHC 3163 (Pat)) Mann J found claims 1 and 2 of 576 invalid for obviousness, but otherwise rejected the attacks on validity of both patents. He also found that Saab’s Ballista mine clearing device infringed the claims of 576 which he had held valid, and claims 1 and 3 of 861.

2.  Saab appeals with the permission of my Lord, Kitchin LJ, from the finding of validity of claims 1 and 3 of 861. Atlas appeals with permission granted by me from the finding of invalidity of claims 1 and 2 of 576. On the appeal we were assisted by submissions from Mr James Mellor QC for Saab and Mr Iain Purvis QC leading Mr Tom Alkin for Atlas. Their able and focused arguments enabled the appeal to be heard in considerably less than a day.

3.  Unexploded underwater mines, either tethered or resting on the sea bed, can be cleared in two main ways: by mine-sweeping or mine-hunting. The patents are concerned with the latter activity, in which a specific mine is targeted and exploded individually. There are a number of approaches to how this can be achieved. A diver may fit a clearance charge to the mine manually. This is simple but dangerous, and is limited to the maximum diving depth of the diver. Another way is to deposit a large amount of explosive in the vicinity of the mine, and explode it in such a way as to cause the mine itself to explode. This requires large amounts of explosive to be carried on board the mother ship, which is dangerous. A further method is to use a smaller amount of explosive in a shaped (and therefore focused) charge close to or even fixed to the mine. Of particular relevance to the present case is the use of a remotely operated vehicle or ROV, which is capable of manoeuvring under water and performing various tasks under the control of an operator who is at a safe distance, for example on board a ship. ROVs could carry shaped explosive charges. ROVs carrying explosive were manoeuvered close to the mine and detonated remotely, thereby sacrificing the ROV. Whilst this used less explosive than other methods, the sacrifice of the ROV was expensive.

4.  Explosive charges can be attached to mines in a limited number of ways. One way is by use of a nail gun. Although the surface of the mine is metal, it had been found that, if fired with sufficient force, the nail could be made to penetrate the mine and attach to it without setting off the mine. There was a dispute before the judge as to whether this method of attachment formed part of the common general knowledge: he decided it did not, but that does not matter for the purposes of this appeal.

The 861 patent

5.  The 861 patent has a priority date of 21 September 2010. The patent begins by setting out the various known ways of clearing seaways of historic ordnance. It concludes that the use of shaped charges had become preferred, but that the positioning and fixing of shaped charges remained a “capability gap”. The description continues under the heading “General” with what is effectively a recitation of claim 1:

“In one aspect there is provided in the following an impact initiated attachment device for attachment to a target, the device comprising: a housing having a front face which abuts against the target in use, one or more fasteners, a drive mechanism for driving the fastener(s) from a first position within the housing to a second position protruding from the front face of housing, and a trigger mechanism for triggering activation of the drive mechanism comprising a trigger extending from the front face of the housing.”

6.  The description continues at page 1 line 34 to page 2 line 2:

"Because the trigger extends from the front face of the housing, all that is required to activate the drive mechanism is to press the device onto the surface of the target whereby to press the trigger. It is therefore very simple to operate since the user does not have to place the device and then fire it, which might be particularly difficult in an underwater environment. The user can concentrate on the positioning of the device and simply has to apply some additional pressure to activate the drive mechanism.”

7.  The fasteners may be nails. The main purpose of the attachment device is said to be to attach a “disruptor” (e.g. a shaped explosive charge) to a target. This is achieved by a “grappler” which carries the disruptor. In the specific embodiment of the invention described by reference to the figures, the grappler consists of two assemblies, a barrel assembly which contains the trigger mechanism and an explosive cartridge for firing a nail, and a breech assembly which contains a drive mechanism for releasing and driving a striker to fire the cartridge in the barrel assembly, thereby driving the nail into the target. The description explains that the grappler as a whole is an “indirect acting tool”, presumably because there is no direct mechanical connection between the cartridge and the nail. Figure 2(b), reproduced below shows the barrel assembly:

8.  The trigger, 22, is “a simple protrusion extending through a hole in the front wall 27 of the housing 21”. Depressing the trigger moves shaft 30 against the action of spring 28 so as to release the striker in the breech assembly (not shown, but to the left of the drawing). This in turn explodes the cartridge 24 which fires the nail 23 into the target. The description continues at page 7 lines 21-22:

“The trigger may be direct acting as shown in Figure 2(b) or may act by other means.”

9.  The description of the specific embodiments continues by describing (by reference to Figure 2(c) reproduced below) an alternative barrel assembly in which the shaft 30 is replaced by a chamber 31 which is open to the atmosphere through access holes 33 and 34. The access holes allow the chamber to fill with water when the device is submerged. This means that the device is inoperative when in air, because the air will be compressed and flow out of the access holes if the trigger is activated. When submerged, however, the chamber will fill with water. As the trigger is moved, the device is arranged to seal off the access hole 34 so as to create an incompressible column of water which then presses against the head of a piston 32. The remaining operation of the trigger and drive mechanisms is the same as Figure 2(b).

10.  It is sufficient to set out claims 1 to 3 of the 861 patent:

1. An impact initiated attachment device for attachment to a target, the device comprising:

a housing having a front face which abuts against the target in use,

one or more fasteners,

a drive mechanism for driving the fastener(s) from a first position within the housing to a second position protruding from the front face of the housing, and

a trigger mechanism for triggering activation of the drive mechanism comprising a trigger extending from the front face of the housing.

2. An attachment device as claimed in claim 1 in which the drive mechanism is arranged to detonate a cartridge containing explosive material to cause the fastener(s) to be driven to the second position

3. An attachment device as claimed in claim 1 or claim 2 in which the drive mechanism includes a striker within the housing which is forced in a direction towards the front face in response to pressure on the trigger from outside the housing towards the front face.

11.  The sole issue on the appeal in relation to this patent is the correct construction of the final phrase in claim 1: “a trigger mechanism for triggering activation of the drive mechanism comprising a trigger extending from the front face of the housing”. Atlas contend that the words limit the claim to a mechanical trigger mechanism, whilst Saab contend that the words cover any type of sensor and activation system, including electronic ones or indeed anything else. The issue has agreed consequences for the validity of claims 1 and 3 of 861. If Saab is correct, those claims are invalid.

12.  The judge dealt with this issue in the following way. He first pointed to two definitions from the Oxford Dictionary of English. The first was the definition of "trigger" which is:

"a small device that releases a spring or catch and so sets off a mechanism, especially in order to fire a gun";

13.  The second definition was that for "mechanism" which is:

"a system of parts working together in a machine; a piece of machinery".

14.  He continued at paragraph 66-67 of his judgment as follows:

“66. Thus the conventional use of the phrase supports the conclusion that a mechanical, and not (for example) an electrical mechanism is required. This gains further support from within claim 1 itself in the reference to the trigger "extending from the front face of the housing", which clearly suggests a mechanical part at least at that stage of the chain of action.

67. Nothing in the description in the patent points in any other direction. At page 7 it describes a plainly mechanical trigger. It goes on to describe an alternative system, again obviously purely mechanical.”

15.  He then went on to consider an argument based on a passage in the specification which claimed that the arrangement was less susceptible to stray electromagnetic fields than “current methods”. This passage was said to indicate an aversion to the use of electronics, and therefore of non-mechanical trigger mechanisms. The judge placed no reliance on this argument. He was plainly right to do so, as claim 1 is not limited to mine clearance devices, which is the only field in which it was suggested that stray electromagnetic fields might be a problem.

16.  Mr Mellor submitted that the judge had adopted the wrong construction. I would summarise his points as the following:

(i) Whilst the judge was fully entitled to start from dictionary definitions of “trigger” and “mechanism” he had stuck too closely to those definitions when he came to construe the terms in their proper context in the specification in the light of the patentee’s purpose. Both terms could aptly describe other arrangements, which were not exclusively mechanical.

(ii) The judge had not understood the significance of the Figure 2(c) arrangement which made use of the incompressible column of water instead of a shaft. Thus he had said at paragraph 29 of his judgment that Figure 2(c) described “a different mechanical link between the trigger and the ultimate detonating mechanism”, and he had made the same error at paragraph 67, which I have quoted above. In fact the Figure 2(c) arrangement was not a purely mechanical arrangement, but a partly mechanical and partly hydraulic mechanism. If the judge had not made this error he would have appreciated that his “purely mechanical” construction was incorrect.

(iii) The judge had overlooked the contrast on page 7 of the specification between the use of “indirect” and “direct” acting. The grappler as a whole was referred to as “indirect acting” because of the use of an explosive cartridge to fire the nail. Thus when one came to the passage at line 21 which said that the trigger may be direct acting (i.e. purely mechanical) or may act “by other means”, the reader was being told that the trigger could be indirect, and thus, he submitted, not purely mechanical.

(iv) There was support for the wider construction in claims 2 and 3. Claim 2 reflected the fact that the drive mechanism of claim 1 was not purely mechanical, as it employed an explosive cartridge to drive the fastener, which Mr Mellor described as a chemical mechanism. Claim 3 refers to “pressure on the trigger”, which he submitted could simply be a pressure sensor, not involving mechanical parts.