Saab Seaeye Ltd v Atlas Elektronik GmbH & Anor

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.

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.

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.

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 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.”

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.”

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:

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.”

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).

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.

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.

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";

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

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

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.”

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.

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

Mr Purvis supported the judge’s construction. The judge had fully understood how Figure 2(c) worked. Although the 2(c) arrangement used water, in making the link the water formed an incompressible column which did not differ from the use of a rigid shaft. The patent was not using the term “trigger mechanism” in a metaphorical sense of anything which sets anything else off. Rather the patent was claiming the mechanism, and in particular the trigger itself in purely mechanical terms. For his part he asked rhetorically why the patentee would have specified that the trigger should protrude from the front surface of the housing if it he was not contemplating a mechanical trigger. The judge had correctly appreciated the force of this point.

There was no dispute about the principles which apply to the construction of patent claims. Both parties relied, as did the judge, on the summary in this court’s judgment in Virgin Atlantic v Premium Aircraft [2010] RPC 8 at [5]:

“(i)

The first overarching principle is that contained in Article 69 of the European Patent Convention.

(ii)

Article 69 says that the extent of protection is determined by the claims. It goes on to say that the description and drawings shall be used to interpret the claims. In short the claims are to be construed in context.

(iii)

It follows that the claims are to be construed purposively – the inventor's purpose being ascertained from the description and drawings.

(iv)

It further follows that the claims must not be construed as if they stood alone – the drawings and description only being used to resolve any ambiguity. Purpose is vital to the construction of claims.

(v)

When ascertaining the inventor's purpose, it must be remembered that he may have several purposes depending on the level of generality of his invention. Typically, for instance, an inventor may have one, generally more than one, specific embodiment as well as a generalised concept. But there is no presumption that the patentee necessarily intended the widest possible meaning consistent with his purpose be given to the words that he used: purpose and meaning are different.

(vi)

Thus purpose is not the be-all and end-all. One is still at the end of the day concerned with the meaning of the language used. Hence the other extreme of the Protocol – a mere guideline – is also ruled out by Article 69 itself. It is the terms of the claims which delineate the patentee's territory.

(vii)

It follows that if the patentee has included what is obviously a deliberate limitation in his claims, it must have a meaning. One cannot disregard obviously intentional elements.

(viii)

It also follows that where a patentee has used a word or phrase which, acontextually, might have a particular meaning (narrow or wide) it does not necessarily have that meaning in context.

(ix)

It further follows that there is no general 'doctrine of equivalents.'

(x)

On the other hand purposive construction can lead to the conclusion that a technically trivial or minor difference between an element of a claim and the corresponding element of the alleged infringement nonetheless falls within the meaning of the element when read purposively. This is not because there is a doctrine of equivalents: it is because that is the fair way to read the claim in context.

(xi)

Finally purposive construction leads one to eschew the kind of meticulous verbal analysis which lawyers are too often tempted by their training to indulge."

Sub-paragraph (ix) must now be read in the light of the Supreme Court’s judgment in Actavis v Lilly [2017] UKSC 48, which explains that, at least when considering the scope of protection, there is now a second question, to be asked after the patent claim has been interpreted, which is designed to take account of equivalents. There was some reference in the written arguments to the impact of that decision on the present case. In the end, however, Mr Mellor disclaimed any reliance on any doctrine of equivalence for the purposes of supporting an expansive scope of claim in the context of invalidity. That issue will therefore have to await a case in which we are called upon to decide it.

I should start by saying something about the use of dictionaries. The judge was of course perfectly entitled to inform his judgment by reference to the dictionary definitions to which he referred. It has to be remembered, however, that dictionary definitions are acontextual, and those responsible for formulating them are unlikely to have had the patentee’s specific purpose in mind. In an appropriate context the words “trigger” and “mechanism” can have a meaning which is wider than the purely mechanical. I have no doubt that a gun in which the trigger operates a switch in an electric circuit which in turn releases a striker can properly be regarded as having a trigger mechanism.

In the present case the skilled person would understand from the description and drawings that the trigger mechanism includes more than just the trigger (shown as 22 in the drawings). It includes the parts downstream which react to the activation of the trigger and which lead to the activation of the drive mechanism. As far as the trigger itself is concerned, the claim specifies that it must extend from the front face of the housing. The passage at page 1 line 34 to page 2 line 2, in the general description of the invention, explains the purpose of the trigger being configured in this way. It is so that it can be simply activated by applying pressure against the surface of the target, which occurs on contact with the target. Whilst this is suggestive of a mechanical trigger, it is also consistent with the trigger being a pressure sensor or indeed an electrical push button, both of which would need to be positioned so as to facilitate easy contact with the target. These would all be “a small device that releases a spring or catch and so sets off a mechanism” in accordance with the dictionary definition.

As to what the patentee contemplated for the remainder of the mechanism, it is plain that the purpose of these parts of the mechanism is to convey the fact that contact has been made with the target to the components which release the drive mechanism. The purpose is spelled out in the claim which requires that the trigger mechanism is “for” triggering activation of the drive mechanism. Moreover, within the description of the specific embodiments on page 7 of the specification, the patentee makes a deliberate distinction between “indirect” action, which includes the explosive cartridge used to fire the fastener in the drive mechanism, and “direct” action, which he uses to describe the direct mechanical action of the Figure 2(b) embodiment of the trigger mechanism. The statement that the trigger mechanism may act “by other means” does, in context, suggest that indirect action is included. The skilled reader already has one example of what is contemplated by indirect action, namely the firing of the fastener in the drive mechanism. However Figure 2(c) is then explained. This is not a purely mechanical arrangement, but includes a hydraulic link. Although the water forms an incompressible column, that is a feature of hydraulic systems generally. Reading the description fairly, it is plain that the patentee regards the hydraulic link as within the claim, although not purely mechanical. It is also tolerably clear that the hydraulic link is an example of “other means”, i.e. means which are indirect.

Mr Purvis attempted to meet this point by saying that the patentee was intending to make it clear, by referring to “other means”, that complex gears and levers were covered. These might be regarded as indirect acting, whilst still purely mechanical. I do not think that this is what would be conveyed to the skilled reader. This interpretation ignores the juxtaposition with the indirect action of the drive means.

I therefore respectfully disagree with the judge that there is nothing in the specification to point away from the purely mechanical arrangement. Page 7 of the specification, read fairly, indicates that the patentee is using the expression “trigger mechanism” to encompass more than the purely mechanical. It includes other, indirect, means of communicating the fact of contact with the target to the means for activating the drive mechanism.

I have considered whether there is room for an intermediate construction between the contentions of the rival parties, in which the term trigger mechanism extends to the hydraulic example, but goes no further. I do not think this is a tenable construction. Once the patentee has indicated that he is content for “other means” to be used, I cannot see why the skilled person would be concerned to restrict the meaning of the phrase in that way. It would be strange to single out hydraulic mechanisms, described simply by way of example, but exclude other connections which achieve the same purpose.

In my judgment, the skilled person would understand that the patentee was not limiting himself to purely mechanical arrangements, and was including other means of communicating the fact of contact with the target to the means for activating the drive mechanism. I would therefore allow the appeal on the validity of the attacked claims of 861.

576 has a priority date of 6th August 2010. The focus of this patent is avoiding the need to sacrifice the ROV when the charge has been successfully attached to the target. After setting out some of the technical background to which I have already referred, the specification explains at page 3 line 4:

“The invention is based on the problem of making weapon clearance cheaper without significantly increasing the amount of explosive required.”

The specification goes on to say at page 3 line 29 to page 4 line 5:

"The invention therefore provides for the weapon clearance appliance not to be an integral component of an underwater vehicle but to provide it only as an attachment for an unmanned underwater vehicle. The underwater vehicle is therefore now used only as a transport vehicle for the actual weapon clearance appliance, which is released from the underwater vehicle. For this purpose, the weapon clearance appliance has means for detachable connection to the underwater vehicle. The weapon clearance appliance is therefore separated from the underwater vehicle in the area of the weapon, thus allowing the underwater vehicle to move away from the danger area before the weapon is detonated."

It is the requirement for the weapons clearance appliance to have a “means for detachable connection to the underwater vehicle” which is the issue of construction which arises on the appeal on this patent.

The appliance 10 is arranged to attach to the bow of the ROV 12. The attachment means is in the form of an elastic band (not numbered on the drawing). The central portion of the elastic band acts on a projection 20 on the ROV so as to hold the appliance and the ROV together. On the end of each elastic band is a loop, 38 and 40. Each loop clasps a respective holding element 34 and 36. In the position shown in Figure 3 the holding elements 34 and 36 project out of the appliance. The firing of a cartridge within the appliance, in this embodiment, not only propels the nails 58 and 60 into the target but also simultaneously withdraws the holding elements 34 and 36 so as to release the elastic band. The combined effect of firing the nails and releasing the elastic band is shown in Figure 4. The result is that the appliance is attached to the target and the ROV is released. It can thus retreat to a safe distance before the charge, which remains with the appliance, is detonated.

The final paragraph of the description on page 16 explains:

"The invention makes it possible to provide conventional unmanned underwater vehicles, in particular minehunting drones, with a multiple use, since the actual weapon clearance appliance is provided merely as an attachment to the underwater vehicle. Therefore, only the weapon clearance appliance need be sacrificed during each operation, while the unmanned underwater vehicle can be reused."

Atlas applied successfully before the judge to amend the claims from those contained in the granted patent. Claims 1 and 9 now read as follows:

“1.

Weapon clearance appliance for clearance of underwater mines which have been sunk in waterways, under water by detonation of the mine, wherein

the weapon clearance appliance has means for detachable connection to an unmanned underwater vehicle, with the volume of the weapon clearance appliance being chosen such that the buoyancy force which acts on the weapon clearance appliance under water compensates for the force of gravity acting on the weapon clearance appliance, characterized in that the weapon clearance appliance has a holding apparatus comprising a nail-firing appliance for fixing the weapon clearance appliance to the body of a mine.

9.

Weapon clearance appliance according to one of the preceding claims, characterized by the means for detachable connection of the weapon clearance appliance to an unmanned underwater vehicle and the holding apparatus being designed such that, in order to fix the weapon clearance appliance to the mine when the holding apparatus is activated, the means for detachable connection are operated at the same time, thus releasing a mechanical connection between the weapon clearance appliance and the unmanned underwater vehicle.”

The simultaneous activation of the appliance and release of the ROV, which I have described by reference to Figures 3 and 4, is thus the subject of claim 9. Claim 1 is obviously broader, but nevertheless specifies that the “means for detachable connection” is a feature of the appliance rather than the ROV.

Before the judge the parties’ positions on the construction of the term “means for detachable connection” in claim 1 were as follows. Atlas contended that the language required some sort of active element on the clearance device which did the connecting and disconnecting. Saab contended that a passive element was all that was required. The judge concluded at paragraph 61 that claim 1 did not require an active element on the weapons clearing device. Some passive means would suffice. He considered, however, that a further point arose. This was because the cited prior art (BAe) disclosed a clearance device which could be gripped by a manipulator “hand” on an ROV by means of four flat gripping surfaces on the device. He did not consider that a dedicated gripping area amounted to a means for detachable connection. The judge explained this point further in paragraph 95:

“The word “detachable”, in my view, connotes an “attachment”, and in its context I consider that it requires more than merely gripping. There must be some degree of interlinking. Having a place where the device can be conveniently gripped by something which does no more than grip does not, in my view, amount to “means of detachable connection”. Whether or not a mere grip is an "attachment" (the opposite of “detachment”, and which has to exist before there can be a “detachment”), using that as an isolated expression, and whether or not a grip, by itself, is a “connection”, the composite phrase, to my eyes, requires an attachment in the form of a degree of fixing or interlinking which is not provided by a mere grip. So a site which provides surfaces for gripping is not “a means of detachable connection”.”

On the basis of this intermediate construction of the claim the judge concluded that the addition of some form of attachment going beyond a gripping area was obvious over BAe.

The basis of Atlas’ appeal against this finding of obviousness was that it was not open to the judge to conclude that the apparatus called for on the judge’s intermediate construction of the claim was obvious. The obviousness of such an apparatus had not been properly canvassed with expert witnesses. Moreover, in the absence of a more concrete definition of precisely what modification of the prior art the judge had in mind, it was not possible for the judge properly to address the issue of obviousness.

By a respondent’s notice, Saab submit that the judge’s intermediate construction is incorrect, and that he ought to have adopted Saab’s wider construction. Logically therefore that is the first issue which I ought to address. It is common ground that if Saab’s construction is correct, claims 1 and 2 are invalid over BAe.

Mr Mellor submitted that “means for detachable connection” was a wide, largely functional phrase, which covered any means adapted to achieve that purpose. The “big idea” of the 567 patent was to remove the ROV from the appliance so that it did not have to be sacrificed. Viewed in that context, and with that purpose in mind, the only question which it was necessary to ask was whether there were some means on the appliance to which the ROV could connect and from which it could subsequently detach. The claim was entirely general and was plainly satisfied by anything on the appliance which was adapted for this purpose. Claim 9 was significantly different in that it required the means on the appliance to be “operable”. He accepted that this imported a requirement for something active, but claim 1 had no such language and was correspondingly much broader.

Mr Purvis supported the judge’s construction. He submitted that even though claim 1 did not have the requirement that the means for detachable connection on the appliance were “operable”, it nevertheless required the means to be “owned” by the appliance, not the ROV. He stressed a part of the passage at page 3 line 29 onwards which said the ROV is “now used only as a transport vehicle for the actual weapon clearance appliance”. He said that this excluded the ROV from control of the detachment, meaning this was left to the appliance. The judge’s construction was to be preferred because otherwise the requirement of detachable connection means was given no meaning and effectively written out of the claim. Anything on the appliance could potentially be gripped and released by an appropriately designed ROV.

I consider that Saab’s construction is correct. The language of the claim is in terms of function. Whilst it requires the means for detachable connection to be on the appliance, it is neutral as to the construction of the means by which detachable connection is achieved, or from where the detachment is controlled. The fact that the claim, so construed, is wide is not at all surprising given the width of the description of the inventive concept as expressed in the passages to which I have referred. The skilled person would understand the purpose of the means because this is spelled out clearly in the specification.

Mr Purvis’ reliance on page 3 line 29 and following is misplaced. The passage in question comes after earlier passages which explain that the shaped charge is detonated within the ROV, resulting in the costly loss of the vehicle. The passage on which Mr Purvis relies explains that, in contrast, in the present invention, the weapons clearance appliance is not an integral component of the ROV, but an attachment to it. It is in this context that it is explained that the ROV is “now used only as a transport vehicle” i.e. that it does not include an integral appliance along with which it is detonated. The same teaching is to be found in the concluding paragraph of the specification: see paragraph [31] above. The specification is not teaching that there is no other functionality on the ROV.

I can understand why the judge might have been reluctant to give the claim a meaning which extended to any feature of the appliance which could be gripped, even if it was not adapted for that purpose. However I do not think that the claim, as I have construed it, does extend that far.

In these circumstances it is not necessary to consider Atlas’ appeal on this patent. The question of whether the judge was entitled to find the patent obvious on the intermediate construction does not arise.

I would therefore uphold the judge’s conclusion of obviousness of the 576 patent over BAe, albeit on the basis of the wider construction of the claim.

I would allow the appeal in relation to the 861 patent, but dismiss it in relation to the 576 patent.

I agree.