Sara Lee Household & Body Care UK Limited v. Johnson Wax Limited [1999] EWHC Patents 192 (22nd November, 1999)

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Mr. Simon Thorley Q.C. and Mr. Michael Tappin instructed by Bristows for the Claimant

Mr. David Kitchin Q.C. and Mr. Richard Meade instructed by Taylor Joynson Garrett for the Defendant

1. In these two actions the Claimants sue the Defendants for infringement of their European Patent No. 0 538 957 entitled "Cleansing and freshening unit for a toilet bowl" which is an article referred to in the art as a rimblock.

2. The subject of the first action (Writ issued 4th November 1998) is the Defendants Mark 1 liquid rimblock device whilst that of the second action (Writ issued 22 April 1999) is the Defendants Mark 2 device.

3. The Defendants deny that its products fall within the claims alleged to infringe and challenge the validity of the patent on a number of grounds.

4. There is also an application to amend the Patent in suit to add two further claims (as new claims 2 and 3) as an "unconditional" fall back position in the event that claim 1 is held to be invalid.

5. The subject of the patent relates to a cleansing and freshening rimblock device which is suspended from the rim of a toilet bowl.

It is to be read through the eyes of a skilled man as of its date of filing, 21st October 1992, nothing turning on the precise date.

6. There is no real dispute as to the skilled addressee. He would be someone with expertise in design in the packaging field with knowledge of existing rimblock devices and toilet cleansing substances and at least a general awareness of air fresheners on the market. Such a person would call upon the expertise of others e.g. as to the type of materials to be used in the construction of toilet cleansing devices and in the behaviour of liquids in such devices as well as the formulation of the cleansing/freshener liquids.

Such a person or persons would read the patent well aware of the drawbacks of "solid" rimblocks namely their limited air freshening effect which the present invention is stated to circumvent (see page 1 lines 29 to 45).

The invention the subject of the Patent is stated to be characterised by the features of claim 1 which have been conveniently broken down by the parties as follows:

7. The twofold purpose of the unit is emphasised at Col 1/53- Col 2/4 where it is stated

8. Claim 2 is for a cleansing and freshening unit according to claim 1 characterised in that

9. At Col 2/7 to 16 and Col 3/44 to 55 this preferred embodiment is stated to have the important effect of a delayed action or after effect of the active substance after each flush. As explained the residual water after each flush which lies on the uppermost surface of the porous mass will trickle through the mass and the underlying perforations of the support for the porous mass and hence a cleansing action can continue for a period of time after the flush. [Day 1/105-110.]

It was Mr. Coe's evidence (a packaging consultant acting for the Claimants) that this delayed action effect was not self-evident and would need to be examined scientifically as to its significance.

10. The alleged delayed action of the cleanser although stated to be an advantage over the prior art solid rimblocks is not stated to be an advantage of the unit the subject of claim 1 in spite of the requirement of both claim 1 and 2 of a porous mass arranged in the path of the flushing mater with which liquid from the reservoir is in communication. It is the combination of the container bottom provided with perforations with the porous pad (5A) extending over such perforations which provides the delayed action.

11. The patent provides what it refers to as "one practical example" of the cleansing and freshening unit by reference to three drawings. Figure 1 is a part sectional side elevation sometime after a flush, Figure 2 is the unit directly after a flush and Figure 3 is a refillable bottle (reservoir) as supplied with a cap (14) secured around its mouth.

As illustrated the reservoir or bottle (3) containing a cleansing and fragrancing liquid is inverted and secured in a container (1) having a suspension hook (2) allowing it to be fixed to the rim of a toilet bowl.

12. The device functions as a result of the liquid-permeable closure 4B being so arranged to be in liquid transmissive contact with the porous member 4A. As illustrated and described (Col 3 lines 12 to 17) the porous masses 4A and 4B are in fixed mutual contact. 4B is described as a spongy liquid-permeable closure (Col 2 line 38 and Col 3 line 1) and as illustrated is secured within the mouth of the bottle or reservoir. As explained at Col 3 lines 31 to 40:

13. So far as the scope of protection of claim 1 is concerned there are three matters in contention namely:

It is common ground that none of such words or phases have any special technical meaning.

14. The extent of protection conferred by such claim is to be determined in accordance with section 125(1) and (3) of the Patent Act 1977, namely following the guidance provided by the Protocol on the Interpretation of Article 69 of the European Patent Convention. The claims are to be interpreted by the description and any drawings. They are not to be interpreted over literally nor as a guideline as to what the patentee has contemplated - rather they are to be interpreted as defining a position between these two extremes which combines a fair protection for the patentee with a reasonable degree of certainty for third parties.

In this regard the three Improver questions posed by Hoffmann J. have been cited by the Defendants. In addition the Defendants have referred to the observations of Hoffmann L.J. in Step v. Emson (1993) RPC 513 at 522.

This feature together with the requirement that it is arranged in the mouth of the reservoir (integers (viii) and (ix) supra) are characterising parts of claim 1 which were originally part of claim 2 in the Application as filed. There is an issue as to whether the amendment introducing such features into claim 1 added new matter which is dealt with hereafter.

15. The Claimants contend that the phrase a liquid-permeable closure has a clear functional meaning, namely that in operation the closure restricts the flow of liquid to the porous pad (4A) in a controlled manner so that the porous pad does not become flooded or overloaded with liquid. They contend that whatever form the closure takes it must be designed to permit liquid to pass when required to replenish the porous mass but otherwise to function as a closure, to prevent the passage of liquid, so that liquid does not simply run out of the reservoir (para 17 of their closing submissions).

16. The Defendants contend that permeable is synonymous with porous and such words are used interchangeably in the patent to describe the spongy closure 4B. They refer to dictionary definitions:

17. The phrase "a liquid-permeable closure" is an oxymoron in the sense that the closure allows liquid to flow from the reservoir to the porous pad (4A). Permeable connotes that the holes or pores in the closure barrier are such that the rate of flow of liquid passing through is significantly reduced - if this were not the case then the liquid-permeable closure would merely operate as a conduit without regulating the flow.

18. The evidence of both parties was to the effect that in operation the liquid-permeable closure should function to restrict the rate of flow of liquid from the reservoir to the porous pad.

19. Thus Mr. Coe (para 33 First Report) [See also XX Day 1/15222-15310.] states that the function of the liquid-permeable closure "is to prevent the flow of liquid out of the reservoir except as "demanded" by the porous mass and then in a controlled manner so that the porous mass holds only an amount of liquid suitable for dosing the water during flushing and/or freshening the toilet room by evaporation".

20. Prof. Luckham [Prof. Luckham for the Claimants is a professor of Chemical Engineering at Imperial College, London, specialising in rheology and surfactant technology .] (para 15 First Report) states "the phrase (liquid-permeable closure) refers to a closure through which liquid will pass under the correct conditions but not otherwise". Under cross examination Prof. Luckham considered that without the liquid-permeable closure one would be liable to get flooding and leakage of liquid where the rim of the bottle abuts the porous pad (see XX Day 2/307-312).

21. Dr. Carter [Dr. Carter is an ex-employee of the Defendants with experience in the toilet care field; see also Carter para 5.2 first Report.] (XX Day 3/467-468) in the course of cross-examination about the liquid-permeable closure was asked:

22. Likewise Prof Nikolov [ Prof. Nikolov for the Defendants is at the Illinois Institute of Technology, Chicago and specialises in the study of liquid interface; see also Nikolov para 2.2 first Report and XX Day 3/4196/15.] (XX Day 3/362) in the course of his cross-examination was asked:

23. As regards what may constitute a liquid-permeable closure fulfilling the necessary function of restricting the rate of flow of liquid, clearly the claims are not restricted to the particular arrangement described, namely a spongy closure member (4B) - nor do I think that the word permeable is synonymous with the word porous as used in the phrase "a porous mass 4A" - if that had been so the word porous would have been adopted instead of permeable for the liquid closure.

That which is porous i.e. full or pores or interstices will be permeable but it is also possible to conceive of a solid barrier through which a number of fine holes have been formed (e.g. by drilling). Such a barrier may not be considered to be a porous member yet may well be permeable to liquid i.e. will allow the flow of liquid therethrough to be regulated.[See Coe Day 2/16716-16812; Carter Day 3/4688-47021; Nikolov Day 3/4196-4239.]

24. Whilst claim 1 is clearly directed to the assembled device in operation (the tailpiece to the claim so states) it is equally clear that the device as described in the patent is one which the user will assemble. Figure 3 shows the bottle (3) as a unit which is refillable and which is to be assembled with the container (1) in the manner described at Col 1 lines 8 to 17. In order to be able to invert the bottle in the manner described there must be present some closure which will prevent the liquid contents from spilling out before it has been secured to the container. It is true that the container could be inverted instead of the bottle during assembly but this is not what is disclosed. Hence the closure described in the patent has a threefold function, namely (1) in operation to regulate the flow of liquid from the bottle to the porous pad (2) to allow the bottle to be assembled to the container by inverting the same in the manner described and (3) to allow the bottle to be refilled.

25. The Claimants rightly say that the latter two functions of the closure are only relevant to the case where the bottle is a separate entity from the container as required by claim 2. They say that claim 1 is broader than claim 2 and includes a device in which the reservoir and container form an integral unit. However it was Mr. Coe's evidence that a preassembled device whilst theoretically possible would not be a practical one because the liquid would escape from the bottle in the course of its distribution to the user. At Day 2/164^10-24, Mr. Coe states:

26. Hence in addition to the functional requirement of the liquid-permeable closure of claim 1 of restricting the rate of flow of liquid to the porous mass the closure of claim 2 will allow the reservoir to be assembled and as an option refilled in the manner disclosed in the patent.[see Carter para 5.12 First Report; XX Day 3/473-476.]

(2) The reservoir has a mouth in which a liquid-permeable closure is arranged.

This feature has to be construed in conjunction with the functional words that follow namely

27. The Claimants contend that the closure of Claim 1 does not have to lie wholly within the mouth albeit that which is disclosed does so in order to provide the advantages of allowing the reservoir to be assembled to the container by inverting the same and the refillability of the reservoir - the subject of claim 2.

28. I consider that claim 1 is not limited to the closure being wholly within the mouth of the reservoir and would extend to a closure partly in the mouth and partly outside the mouth provided that in operation it allows a constant flow of liquid from the reservoir to the porous mass (4A).

There is no dispute as to the meaning of such words. The only issue is whether the Mark 2 version which it is accepted does not have a porous mass as such nevertheless is within the scope of protection of claims 1 and 2.

29. Before the court there are two liquid rimblock products alleged to infringe claims 1 and 2 (and the proposed two new claims) namely the Toilet Duck Mark 1 and Mark 2. They are described in the Product Descriptions (Bundle 3 Tabs 7 and 15). The only difference between the Mark 1 and Mark 2 is that the Mark 1 has a porous pad onto which the cleansing and freshener liquid spreads out whilst the Mark 2 has a plastic tray.

The reservoir holds 55ml of liquid and it is stated that it will last up to 500 flushes. In other words after each flush there will be a dose of about 0.1ml of liquid from the porous pad or plastic tray into the toilet bowl and a corresponding amount will be delivered from the reservoir to the porous pad/plastic tray.

30. The Claimants contend that both the Mark 1 and Mark 2 devices have a liquid-permeable closure arranged in the mouth of the reservoir in that there is a plastic insert (identified in green in Diagram No. 1 attached to their Statement of Case and as Figure 3 in the Product Description). The reservoir of liquid (5) is supplied either with the suspendable housing (1) or as a replacement when it is supplied on its own. To prevent leakage of the liquid from the reservoir there is a seal (6(b)) at its mouth which on assembly is broken by the uppermost point of the inlet chamber (8).

31. Illustrated hereunder is a cross section of the reservoir and housing together with the plastic insert once assembled.

The plastic insert comprises an inlet chamber (8) which is located on a shelf (9) in the housing (1) and which communicates with the outlet chamber (10) via a circular hole (9(a)) 3mm in diameter in the shelf.

32. The issue as to the infringement of claim 1 by both Mark 1 and Mark 2 is whether such plastic insert is a liquid-permeable insert and if so whether it is arranged in the mouth of the reservoir.

33. It is not in dispute that in operation the 3mm hole (9(a)) does not restrict the flow of liquid from the reservoir to the porous pad (7) or plastic tray in the case of the Mark 2. As Mr. Coe accepted (Day 2/180¹⁰ to 181⁴) a 3mm or 4mm hole would not regulate the flow of liquid in normal operating circumstances. What controls the flow of liquid from the reservoir in both the wet and dry conditions is a number of interrelated factors as explained by Prof. Luckham. [Day 2/27620-304.]

Thus for the Mark 1 when the system is dry there is a capillary effect in the porous pad and a hydrostatic gravitational force of the liquid in the reservoir both drawing liquid from the reservoir to the porous pad. This is counterbalanced by a partial vacuum created in the headspace above the liquid in the reservoir and an increase of viscosity of the liquid as it spreads out over the porous pad due to the evaporation of the freshener active ingredient. At the time of flushing when the system is wet, in place of the capillary effect there is a diffusion or concentration gradient effect whereby the concentrated liquid from the reservoir is drawn downwards whilst the liquid diluted with water from the flush is drawn upwards.

34. Initially Dr. Carter (para 8.16 of his First Report) considered that the hole 9 (a) in the shelf did affect the flow rate of the liquid from the reservoir to the porous pad. However in his Supplementary Report (para 4.4) having considered Prof. Nikolov's supplementary evidence he was of the view that it had no such effect (see XX Day 3/478-482).

35. Prof Nikolov (para 3.5 of his Supplementary Report) was of the view that as air can readily vent into the reservoir to reduce the partial vacuum which would otherwise be created, whether the hole in the shelf is 3mm or 5mm in diameter would not increase the rate of liquid being dispensed from the bottle [See Day 3/41416-25, 4176-20, 42423-4274.]. It was Prof. Nikolov's view that the hole 9(a) in the shelf was not there to restrict the flow of liquid from the reservoir when in use but may prevent too much liquid being forced out of the reservoir when it is being attached to the dispenser if the user squeezed the plastic bottle too hard. (Day 3/427⁵ to 428²⁵).

36. The Claimants position is that firstly the hole 9(a) will prevent leakage in the event that the reservoir is not properly fitted to the dispenser and secondly that it determines the location or area where the liquid will impact on the porous pad/tray beneath.

As to the prevention of leakage, there is no evidence that in normal operation the hole 9(a) has any effect on the prevention of leakage of liquid. The Claimants rely on an experiment in which the porous pad/plastic tray has been removed to show that after an initial drop, no liquid will emerge from the reservoir. However, firstly the Defendants Toilet Duck devices are never operated without the porous pad/tray and secondly in any event the cause of the liquid being retained in the reservoir would appear to be the partial vacuum in the headspace rather than the 3mm hole in that if the top of the reservoir were punctured liquid would flow out. Thus Prof. Luckham (para 7 of his First Report) states that the experiment "indicates to me that a partial vacuum must be formed in the bottle as the hole at the bottom of the insert is too large for the liquid to be retained solely by surface tension".

37. As to directing the flow to a particular position on the porous pad/tray such a function would be no more than that of a conduit such as a hosepipe and does not restrict the flow of liquid - namely the 0.1ml dose drawn by the porous pad/tray from the reservoir through the 3mm hole after each flush.

38. I do not consider the plastic insert to be a liquid-permeable closure. It does not function in the way the Claimants accept such a closure must function, namely in operation to restrict the flow of liquid from the reservoir to the porous pad/tray. The 3mm hole in the relatively thin shelf of the plastic insert does not regulate or control the flow of liquid when the unit is assembled and in use. It does not provide a liquid-permeable member.

39. Furthermore the plastic insert does not constitute a closure at any time. The only liquid closure is the seal at the mouth of the reservoir which is broken by the insert on assembly.

40. It is further contended by the Defendants that the plastic insert is not arranged in the mouth of the reservoir as required by Claim 1 as the only part of the insert in the mouth is the inlet.

I have already referred to this feature (under Construction) and have held that it is not restricted to the whole of the insert having to be within the mouth provided that it is such that the reservoir has its contents in constant communication with the porous mass. If the insert were held to be a liquid-permeable closure then I consider it would also be correct to view the insert as being in the mouth of the reservoir.

41. The issue with respect to the Mark 1 device is whether the container has a bottom provided with perforations over which the porous pad is positioned.

The purpose of such perforations being to hold up the water on the porous pad to allow a delayed action or trickling through of the cleansing liquid after each flush.

In my view the Defendants' device does not have such perforations rather it has an open T shaped aperture which will not hold up water in the porous pad.

42. In addition to the foregoing as already stated, the Mark 2 device in place of the porous mass 4A required by Claim 1 has a plastic tray which has a series of grooves or open channels which fan out over its top surface. These channels act as capillaries albeit to a lesser extent than a porous pad would do so. An important difference is that whilst the porous pad in combination with the perforations of the device the subject of claim 2 allows a delayed action, no such delayed action could occur in the Mark 2 device not only because it does not have the required perforations (see supra) but also because it does not have a porous mass through which the liquid may pass.

(1) Do the differences outlined above have a material effect upon the way the invention works.

The working of the invention is as referred to in claim 1 namely the twofold purpose of (1) spreading a fresh odour in the toilet room and (2) introducing active substances into the flushing water with each flush.

(a) Liquid-permeable closure: the absence of a closure which is liquid-permeable will allow air to vent into the reservoir and avoid the problems which are inherent in a liquid-permeable closure such as the porous/spongy bung disclosed in the patent.

That this is a real problem with a liquid-permeable closure can be seen from the Claimants' later filed patent application EP 0785315 where it is acknowledged in Col 1 lines 5 to 19 that a drawback of the device the subject of the patent in suit is that due to the porous bung air can only flow into the bottle/reservoir with difficulty so that there is a risk of reduced pressure being formed in the bottle which substantially limits the draining of the bottle. [ See Prof. Luckham Day 2/342,344,348.]

43. Much evidence was directed to the extent air bubbles would penetrate a porous bung. Prof Nikolov in Appendix 2 to his First Report carries out a calculation much criticised by the Claimants. I have not found any of this evidence directed as it is to a specific case of any assistance.

However Prof. Luckham does accept that it would be harder for an air bubble to go up through a porous mass than it would be to go up through a fairly large hole (see Day 2/336). Furthermore the passage of air through a porous material (as opposed to a single hole) could well be affected by becoming clogged with particulate material (see Day 2/346).

44. I consider that the substitution of a 3mm hole for a liquid-permeable closure such as a porous bung will have a material effect on the way the device will operate in particular with regard to the regulation of liquid from the reservoir to the porous pad/tray.

(b) porous mass: whilst the substitution of a porous pad by a plastic tray will have a material effect on the way the delayed action works (claim 2 feature) it is less clear to me what effect a plastic tray has over the general operation of the device compared with the same device with a porous pad. Both devices will allow liquid to be spread over the surface of the pad/tray and on flushing both devices will allow the active substances to be flushed away with each flush.

It is true that the capillary effect of an open channel of the Mark 2 plastic tray is less than that of a porous pad and there may be a Maragoni effect due to differences in surface tension not present in a porous pad. However I consider these differences are matters of degree and do not affect broadly how the invention claimed in claim 1 works.

(c) Perforations in the bottom of the container : the absence of such perforations will have a material effect on the way the device operates in that their purpose is to hold up or delay the introduction of cleansing liquid into the toilet bowl.

(2) Even if the variation would have no material effect on the working of the invention would this fact have been obvious at the date of publication of the patent to a reader skilled in the art.

This question only applies to the substitution of the porous mass by the plastic tray of the Mark 2 device.

The evidence is that a skilled rheologist would have appreciated that a plastic tray with open channels would operate by a capillary action and/or diffusion action (in the wet) in a manner similar to that of a porous pad - see Luckham para 42 First Report and Mr. Coe para 48 First Report not cross examined.

(3) Are the words of the claim essential requirements of the invention such that strict compliance with their primary meaning was intended by the patentee.

The requirement of a liquid-permeable closure is not simply to control or regulate the flow of liquid from the reservoir to the porous mass. It also has the advantages of allowing the reservoir to be assembled to the container by holding it upside down in the manner described. Furthermore as a spongy bung it allows the reservoir to be refilled.

45. Together with the porous mass it allows liquid to be regulated in the manner claimed. Both items are in my view essential requirements of the invention. Indeed the Claimants in para 57 of their closing submissions rely on both the porous mass and the liquid-permeable closure as being part of their inventive concept. Furthermore the porous mass is essential to the delayed action feature which is stated to overcome an important drawback of the prior art solid rim block devices (see Patent Col 1 lines 37 to 45 Col 2 lines 5 to 23 and Col 3 lines 44 to 55).

46. Hence even if, contrary to my view, the Defendants' plastic insert has no material effect on the working of the invention claimed in claim 1, I consider a skilled reader would understand that a liquid-permeable closure combined with the porous mass to be essential requirements of the invention.

47. For the foregoing reasons I find that neither Mark 1, nor Mark 2 infringes claim 1 or claim 2 of the patent in suit. It follows that neither product would infringe either of the proposed dependent clams if the same were allowable.

49. It is common ground that the following constituted common general knowledge as at the priority date.

I agree with the Claimants that such a distinction should be borne in mind and that the knowledge of the notional team of air fresheners would not necessarily extend beyond an ordinary consumer's appreciation of the well known air fresheners on the market such as the AIRWICK product. (See Col XX Day 1/91-98, Day 2/191-192).

50. Reinders relates to a rimblock device in which a water activable agent is stored in a small hollow tube filled with an absorbent material such as cotton or fibre which accommodates the water activatable agent. Water flows into the tube which is secured in a housing and dissolves some of the active substance in a manner that causes a delayed discharge.

It is accepted by the Defendants that Reinders does not anticipate claim 1 of the patent in suit unless integers (vi) and (ix) thereof (a porous mass and a liquid-permeable closure) are treated as a single item or component. (See Carter para. 9.29 First Report).

Such a reading of claim 1 is incorrect as is accepted by both parties (Carter para. 8.10 First Report, Coe para 62 First Report). Reinders does not anticipate claim 1.

The Defendants also contend that Reinders is a "workshop modification" of claim 1.

No evidence has been directed to why one would consider modifying the Reinders tubular container to create a separate liquid closure which would allow liquid to flow from the reservoir onto a porous mass. Reinders does not render claim 1 obvious.

51. Henkel relates to a liquid rimblock device. In Figure 1 a porous mass is located at both ends of a tubular container (the reservoir) which is suspended in the toilet bowl. In Figures 2 and 3 (for which there is no description other than that which can be inferred from the claims) the porous metering medium is positioned not at the ends of the tubular container but in the middle thereof either projecting from the upper surface or the lower surface in the form of a cylindrical wick.

52. For similar reasons to those that apply to Reinders, Henkel does not anticipate claim 1 because it does not have both integers (vi) and (ix) thereof. The porous metering medium does not have the separate functions of a liquid-permeable closure and a porous pad onto which liquid from the reservoir is metered. (See Carter para 9.18 of his First Report; Coe para 76 of his First Report).

53. As to whether it would be obvious to modify the Henkel device to create a porous mass separate from the liquid-permeable closure. The Defendants lead no evidence as to this issue.

Mr. Coe did not believe there would be any reason for creating a porous mass separate from the liquid-permeable closure and he considered Henkel would be a document he would have consigned to the bin being more of a piece of work that had not been thought through, more of an idea session than the basis from which to work. (Day 2/226-233).

54. Dr. Carter agreed that the drawings and description of Henkel are not the best but nevertheless considered it "gives one quite a number of ideas. It just lists them ... even though the designs in here may not have been carried too far". (Day 3/516-517).

I do not consider the evidence establishes that it would have been obvious to modify any of the three devices of Henkel to come up with a device having a separate liquid-permeable closure arranged in the mouth of the reservoir and a porous mass on which liquid from the reservoir may be retained. Claim 1 is not obvious over Henkel.

À fortiori claim 2 (proposed new claim 4) is not obvious. It not only requires the reservoir to be separate from the container but also the container to have perforations in the bottom on which the porous mass is supported.

55. Dupuy which was published on the 6th October 1949 relates to an air freshener having an inverted reservoir of liquid which sits on a porous pad made of felt or the like. The reservoir has a bung or stopper in its mouth which has a conduit or opening through which liquid flows. In the Figure 1 embodiment the liquid flows out of the reservoir through the opening in the bung and then through a wider opening in the felt pad in register with the opening in the bung. The underside of the pad only has a channel in which the liquid flows so that the pad will become fully saturated over its whole surface.

56. In the Figure 4 embodiment corrugations in the holder take the place of the channel. The reservoir is shown in Figure 1 as being encased in a cardboard housing which has holes in it and an outer housing or sleeve with slots which can be moved to open or close the holes of the inner housing.

The problem to which Dupuy is directed is a problem peculiar to an air freshening device namely how to maintain the pad saturated with liquid air freshener. The solution is the distribution of liquid via the liquid channels created underneath the felt pad.

57. The evidence was that such a device would be difficult to get to work. The opening in the bung of the reservoir will not prevent the liquid flowing out of the bottle and it is unlikely that there will be the necessary balance between the rate of evaporation of liquid from the pad and the rate of flow out of the bottle - see Coe paras 89 and 90 First Report and Carter Day 3/499-500.

58. The real question is why would such an unpromising air freshener device be considered as the basis for converting to a liquid rimblock device.

The evidence as to this is that Mr. Coe would not have thought it was (paras 91 and 92 of his First Report and XX Day 2/193-211) and Dr. Carter's evidence was that such an idea (i.e to consider Dupuy for a toilet care application) would have only come out of a brainstorming session from an air care person. - see Carter Day 3/496-7; 501-2; 524.

It is just such cross-fertilisation of ideas which gives rise to the spark of invention. Solid rimblock devices have been known for many years with their inherent drawbacks and yet no liquid rimblock device had been produced. Henkel's ideas (which clearly were not common general knowledge) relate to a liquid rimblock device which did not result in a device falling within the claims of the patent.

Even if the notional team had been presented with Dupuy and told to develop it into a liquid rimblock device it is not at all clear that they would have ended up with a device having both a porous pad and a liquid-permeable closure in the mouth of the reservoir as opposed to retaining the bung with a hole in it through which air can access to satisfy the partial vacuum. (see Col 1 lines 52 to 55).

59. For the foregoing reasons I do not consider Dupuy renders claim 1 obvious. A fortiori claim 2 which requires perforations in the bottom of the container is not obvious. Such a construction goes against the whole teaching of Dupuy where the porous pad is required to be saturated in the freshener liquid by reason of the channels underneath the pad.

60. Section 72(1)(d) provides that a patent may be revoked if the matter disclosed in the specification of the patent extends beyond that disclosed in the application for the patent as filed.

As already indicated in the course of prosecution of the Application for the patent in suit, the requirement of the presence of a liquid-permeable closure arranged in the mouth of reservoir which was a feature of claim 2 of the Application was made a characterising feature of claim 1.

In the Application as filed the only disclosure of such a feature was in relation to the preferred embodiment of the invention in which there was a separate reservoir and container and therefore the closure provided the added benefit of ensuring that when the reservoir was assembled by inverting the same over the container and snapping it on liquid did not spill out of the reservoir.

If and insofar as the requirement of a liquid-permeable closure in claim 1 can be construed to apply to a device which does not have a separate reservoir the Defendants contend that there is no disclosure of a combination of such features but only a combination of the features of claim 2 of the Application as filed in which the closure is combined with a separate reservoir and retaining means.

61. In cases such as this, the legal principles to be applied as set out in T582/91 (Metal Fren) are not in dispute.

At point 2.2. the Board of Appeal in considering the requirement of Article 123(2) of the EPC stated that a feature of a dependent claim can be combined with a preceding independent claim "as long as the skilled person recognises that there is clearly no close functional or structural relationship between the one feature of that dependent claim and its other features or between that one feature and the teaching of other dependent claims referred to in that dependent claim".

62. The requirement of a liquid-permeable closure in the mouth of the reservoir as disclosed in the Application as filed is firstly so that it can restrict the flow of liquid from the reservoir to the porous mass, secondly so that the reservoir can be assembled by inverting it and snapping it onto the container base and thirdly to allow the reservoir to be refilled.

In my view such functions of the liquid-permeable closure are independent of the other features of claim 2 such as the retaining means and perforations in the bottom of the container. Hence the addition of such feature to claim 1 has not added any subject matter to the patent as granted. The functions of the liquid-permeable closure in the mouth of the reservoir remain the same.

63. The Claimants seek to add the following claims as claims which are dependent on claim 1

2. A cleansing and freshening unit according to claim 1 characterised in that the reservoir (3) is a component separable from the suspension means and the porous mass (4A).

3. A cleansing and freshening unit according to any of claims 1 to 3 characterised in that when the unit has been suspended in a toilet bowl, the mouth (11) is at the bottom of the reservoir (3) and the porous mass (4A) is positioned below the mouth (11) and extends beyond the mouth (11) to form a lateral surface.

64. The reason for seeking to add such new claims is stated to be "for the purpose of distinguishing (more clearly) the invention of the patent over Henkel" - see para 2 of the Amended Statement of Reasons. Manifestly this cannot be so because no limitation of claim 1 is sought. The true position is that the Claimants wish to have their cake and eat it by adopting a fall back position in the event of claim 1 being held to be too broad instead of making an election as to whether or not to restrict such claim to one or more features of the proposed new claims 2 and 3.

65. The Defendants say that such an amendment is impermissible because it does not seek to meet the ground of invalidity since no revision of claim 1 is sought. They say that such an amendment is neither in accordance with long established UK practice nor EPO opposition practice.

66. In Raleigh Cycle Coy Ltd v. Miller H & Coy Ltd (1950) 67 RPC 226 at 230 lines 1-9 Lord Norman states that having been put on notice of the attack on the validity of the claims the patentees were "put to an election between amending these claims and continuing their action without amending while maintaining that the claims were valid. They chose the second alternative and now seek all the advantages of amendment which they then rejected. Without going so far as to say that a patentee can never in any circumstances be allowed to do this, I think that he cannot be allowed so great an advantage except in very special circumstances which are not here present".

67. The practice at the EPO Opposition stage is that to be allowable an amendment must be in accordance with Rule 57a namely "the amendments are occasioned by grounds for opposition specified in Article 100 even if the respective ground has not been invoked by the Opponent" (Rule added as of 1st June 1995).

In T829/93 (British Telecommunications) the Board of Appeal refused to allow a patentee to add new dependent claims. They stated (point 5) that amendments should only be admitted if they can influence the decision on issues under Article 100 EPC and that new Rule 57a corresponds to this established case law. The Board went on state (Point 6.3). "In opposition proceedings the filing of new dependent claims just for improving such fall back position is in no way necessary or appropriate". This is to be contrasted with the putting forward of auxiliary sets of claims in the event that the claims as granted fail.

68. I do not consider that the proposed addition of new claims 2 and 3 by way of a fall back position is an appropriate exercise of the court's discretion under section 75. Such an amendment does not seek to distinguish claim 1 from Henkel (as pleaded in the Amended Statement of Reasons) it merely adds two new claims which the court is asked to consider as to their validity which in the event that claim 1 is upheld makes it an academic exercise and a waste of court time as well as adding to the overall costs.

Mr. Thorley Q.C. for the Claimants contends that Henkel only came to light in the course of proceedings in France in the early part of 1999. However had Henkel emerged in the course of Opposition proceedings at the EPO, the Claimants still would not have been able to amend to add new dependent claims in the manner sought. Following the BT case such an amendment would not have been considered to arise out of the grounds for opposition.

69. Had I not come to the conclusion that the type of amendment sought is one that I do not consider to be a proper exercise of my discretion I would not have refused such an amendment on the more general grounds of discretion of delay or failure to disclose documents.

70. Nor do I consider such amendments are objectionable as adding matter by seeking to generalise a feature only described as a specific combination.

71. Claim 2 relates to a separable reservoir. I do not consider such a feature to be dependent on the use of a spongy bung and hence can only be viewed in the Application as filed when combined with such a bung. A separable reservoir could be fitted without a bung by inverting the container as was made clear in the evidence (e.g. Coe Day 1/147-151).

72. Claim 3 is for a combination of features viz that the mouth of the reservoir is at the bottom, the porous mass is below the mouth and that it extends to form a lateral surface. I consider such features as disclosed in the Application as filed are not to be limited to the specific "generally disc-shaped" porous mass other shapes of porous mass could be used or that the porous mass should be in contact with the liquid-permeable closure. It is the contents of the reservoir that are disclosed as being in constant communication with the porous mass.

73. The Claimants criticised the evidence of Prof. Nikolov and contended that in so far as his evidence was relevant I should not place any weight on it. They say that in his first report he only considered the capillary action of the liquid and omitted to consider the effect of diffusion - yet in his second report having considered Prof. Luckham's first report he (wrongly) contended the diffusion effect would be the dominant effect. They also say that even considering capillary action when calculating how long it would take an air bubble to pass through a 1cm porous bung in his Appendix 2 he failed to take into account the critical micelle concentration (CMC). In so doing he failed to appreciate the fact that over the majority of the length of Prof. Nikolov's notional capillary the surfactant concentration would be above the CMC and so the surface tension gradient would be close to zero.

74. As I have already indicated I have not found helpful and have not relied upon the evidence as to precisely how long it takes an air bubble to pass through a notional 1cm porous bung. Nor have I considered it relevant as to the relative importance of the capillary action and the diffusion effect. Both Prof. Nikolov and Prof. Luckham entered into an overly detailed analysis of the functioning of a notional porous bung which was way beyond that which a member of the team of skilled persons would indulge.

At the more general level there was a substantial measure of agreement e.g. that air venting using a porous bung causes problems which an orifice in a bung or plastic shelf would not.

75. For the above reasons I have not considered it necessary or helpful to resolve the various conflicts of evidence between Prof. Nikolov and Prof. Luckham. It was not suggested Prof. Nikolov was deliberately misleading the court rather that I should proceed with caution in accepting his evidence in preference to Prof. Luckham. This I have done.

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You are here: BAILII >> Databases >> England and Wales High Court (Patents Court) Decisions >> Sara Lee Household & Body Care UK Limited v. Johnson Wax Limited [1999] EWHC Patents 192 (22nd November, 1999) URL: http://www.bailii.org/ew/cases/EWHC/Patents/1999/192.html Cite as: [1999] EWHC Patents 192

England and Wales High Court (Patents Court) Decisions

Sara Lee Household & Body Care UK Limited v. Johnson Wax Limited [1999] EWHC Patents 192 (22nd November, 1999)