“This invention relates to a multi-cyclone dust separator and to a vacuum cleaner using the same, and in particular to a multicyclone dust separator comprising a plurality of cyclones to separate dust particles sequentially according to size, and to a vacuum cleaner using the same.”
“That vacuum cleaner has a first cyclone separator mounted in a lower part of a housing, and a second cyclone separator mounted above the first cyclone separator. According to this structure, relatively large dust particles included in drawn-in air are separated in the first cyclone separator, and relatively fine dust particles are separated in the second cyclone separator. However, in such a two-step cyclone separator, suction efficiency is imperfect. An aim of the present invention is to provide a multi-cyclone dust separator capable of improving suction efficiency by providing a plurality of cyclone separators for sequentially separating dust according to size, and to [sic] a vacuum cleaner using the same.”
“By using the above multi-cyclone dust separator, dust particles can be sequentially separated according to their sizes, thereby enhancing the suction efficiency. In addition, by incorporating the multi-cyclone dust separator in a vacuum cleaner, cleaning efficiency can be improved.”
“The air, from which the relatively large dust particles are separated by the first dust separation unit 30, passes through the first air outlet 35 of the first chamber 31, and ascends along the intermediate path formation member 213. Then, the air is drawn into the second chambers 211 in a tangential direction through the intermediate connection path 215. Because the air ascending along the intermediate path formation member 213 is radially diverged by the intermediate connection path 215, the volume of the air current is reduced. Accordingly, separation of dust particles in the second dust separation unit 200 can be more easily achieved. The air entering the chambers 211 is again centrifuged…”
“The discharged air enters the third chambers 311 of the third dust separation unit 300 through the upper path formation member 313, and is then centrifuged in the same manner as in the second dust separation unit 200.”
“A cyclonic dust-separating apparatus includes a cyclone chamber in which the drawn-in air is rotated. The cyclone chamber is sized to suit the dust to be removed, and generally a cyclonic dust-separating apparatus has a single cyclone chamber. Accordingly, a conventional cyclonic dust-separating device can only separate dust particles that are large enough to be handled by the structure of the cyclone chamber. Such a limited cleaning operation is disadvantageous, especially for a cyclonic dust-separating apparatus of a vacuum cleaner, which is required to separate almost every dust particle regardless of size. The conventional cyclonic dust-separating apparatus is particularly poor at removing fine dust particles. In order to solve this problem, studies have recently been carried out to develop a cyclonic dust-separating apparatus that has a plurality of cyclone chambers for separating dust in multiple stages. The problem of this approach is that, as the number of cyclone chambers increases to satisfy the desired dust separation efficiency, the overall size of the apparatus increases and its structure is complicated, which is obviously not beneficial for use in a vacuum cleaner. An aim of the invention is to provide a cyclonic dust-separating apparatus that is compact whilst providing improved dust separation efficiency.”
“Accordingly, this multi-stage cyclonic dust-separating apparatus can improve cleaning efficiency while remaining compact.”
“Referring to Figures 3 and 4, the cyclonic dust-separating apparatus 200 includes a first cyclone chamber 310, at least one second cyclone chamber 320, and at least one third cyclone chamber 330. Accordingly, dust is separated from the drawn-in air in three stages, thereby leading to an improved dust separation efficiency. The cyclonic dust-separating apparatus 200 actually includes one first cyclone chamber 310, and a plurality of second and third cyclone chambers 320 and 330.”
“The third cyclone chambers 330 are provided to filter the air flowing in from the second cyclone chambers 320, so as to separate even smaller dust particles D3 from the air. For a higher separation efficiency, the third cyclone chambers 330 have a smaller size than the first and second cyclone chambers 320 and 330. In this particular embodiment, the second cyclone chambers 320 are smaller than the first cyclone chamber 310, and larger than the third cyclone chambers 330.”
“The dust receptacle 220 is provided with a partition 221 which divides the interior of the receptacle into a space for receiving the dust particles D1 separated in the first cyclone chamber 310 (i.e. in the first collecting space 225), and a space 227 for receiving dust particles D2 and D3 separated in the second and third cyclone chambers 320 and 330.”
“The common general knowledge is the technical background of the notional man in the art against which the prior art must be considered. This is not limited to material he has memorised and has at the front of his mind. In includes all that material in the field he is working in which he knows exists, which he would refer to as a matter of course if he cannot remember it and which he understands is generally regarded as sufficiently reliable to use as a foundation for further work or to help understand the pleaded prior art. This does not mean that everything on the shelf which is capable of being referred to without difficulty is common general knowledge nor does it mean that every word in a common text book is either. In the case of standard textbooks, it is likely that all or most of the main text will be common general knowledge. In many cases common general knowledge will include or be reflected in readily available trade literature which a man in the art would be expected to have at his elbow and regard as basic reliable information.”
“I have emphasised some more general points of cyclone technology but these are easily accessible through the reading of standard textbooks on gas cleaning technology and it would be expected that a competent person skilled in the art would have made some effort to understand cyclones in general as well as their application to vacuum cleaners. Thus some, possibly patchy, knowledge of the industrial cyclone technology would be expected.”
“[Centrifugal force] causes the particles to migrate outwards with respect to the fluid.The fluid in the outer spinning layers of the vortex acquires a greater concentration of particles so that the particles are no longer in the fluid in the centre layers. If arrangements can then be made to provide for effective disengagement of the concentrated dust stream from the fluid in the centre then the particles have been separated. This is the underlying principle of the separation effect of cyclones.”
“Separation is the removal of particles from an airflow. Collection is the depositing of particles into a location from which re-entrainment is unlikely (for example a dust hopper). In a reverse flow cyclone, all collected particles have been separated from the airflow and so the terms are often used interchangeably. The skilled person would, however, understand that these terms refer to different stages of the process. In a cyclone using a scavenge flow, dust particles are separated from the main airflow and are concentrated in the scavenge flow before leaving the cyclone. Subsequent arrangements may be made to collect the particles from the scavenge flow.”
“[Centrifugal force] causes the particles to migrate outwards with respect to the fluid.The fluid in the outer spinning layers acquires a greater concentration of particles and the fluid in the centre layers is effectively cleaned. This is the underlying principle of the separation effect of cyclones.”
“It was capable for a range of meanings. I keep saying the words ‘in the context’. If you were talking about how particles achieve the concentration, you could perhaps talk about particles migrating through the gas and you could perhaps call that separation if you were not thinking about it and if there was no need for you to make a distinction in a particular set of circumstances in which you were operating. … I have said that people used the word ‘separation’ in a number of ways. I have said to you that if you start to talk about the force balances on the particles within a vortex and then you talk about the particles migrating outwards with respect to that vortex, it is quite common for people to refer to that as separation. … On the other hand, if you start to talk about whether or not a cyclone separates, moving to the bulk thing, the tendency is, and it is by no means absolute because people write in different ways and write with different degrees of rigour, and all the rest of it, to perhaps move more towards the use of separation in the terms which I have used it. Even then it is quite possible to find people using it in a range of ways, as I myself did in the year 2000.”
“In gas cyclones the particle density is much higher than that of the carrier gas, so the ‘boyancy’ [sic] is low and the particle will move radially outward in the vortex. This, then, becomes and defines the primary mechanism for separation of particles in a cyclone. … This outward movement of the particle is, as mentioned, the principle of separation in all centrifugal separators, both for dedusting and demisting.”
“an electrical appliance for removing dust (from carpets and other floorings, soft furnishings, etc.) by suction.”
“The principle of separating the dust will briefly be explained. The external air is tangentially drawn in along an inner wall of the first chamber 31. As it rotates along the inner wall of the first chamber 31, the drawn-in air generates a centrifugal force. Since the air, which is relatively light, is less influenced by the centrifugal force, the air gathers at the centre of the first chamber 31, thereby generating a whirling current, and is discharged towards the first air outlet 35. On the other hand, the dust (being heavier than the air) is influenced to a greater extent by the centrifugal force. Therefore, the dust flows along the inner wall of the first chamber 31, and is collected in the first dust receptacle 111.”
“Referring to FIG. 2, the vacuum cleaner has a filter assembly 30 comprising a first stage cyclone 32. First stage cyclone 32 may, if desired, comprise a plurality of individual cyclones through which the air passes either in sequence or in parallel. Preferably, filter assembly 30 uses only one first cyclone 32. Such a single cyclone may be designed to remove approximately 90% of the particle matter in the air stream entrained by the vacuum cleaner.”
“Electronic filter 50 may be removable so that it may be cleaned, such as by rinsing with water to remove the particulate matter which is collected thereon. Electronic filter 50 may be of any particular construction known in the art. Various constructions for electrostatic devices which use charged regions to remove particulate matter from an air stream are known. In a particular preferred embodiment, electronic filter 50 comprises an electrostatic precipitator. The electrostatic filter is preferably designed to remove the smallest portion of the particulate matter from the air stream (e.g. up to 30 microns). However, the actual level of filtration which may be achieved by the electrostatic filter will vary depending on the design of filter.”
“Clean air [from outlet] 74 may be fed, if desired, to further filtration means, such as additional cyclones (i.e. third stage cyclones) or a HEPATM filter.”
“The instant invention provides an alternate approach to the use of such HEPATM filters. Electrostatic filters generally provide minimal resistance to the flow of air and accordingly do not provide much of the pressure drop as an air stream passes therethrough. Electrostatic filter 50 may be designed to remove the same size particles as are removed by the HEPATM filter which is currently in use. Alternately, electrostatic filter 50 may be designed to remove even larger particles. Accordingly, by using an electrostatic filter, the pressure drops for a vacuum cleaner may be substantially reduced (compared to a vacuum cleaner using a HEPATM filter).”
“This invention relates to a cleaning machine, in particular a cleaning machine which comprises a suction blower driven by an engine and mounted on a frame, a dirt intake communicating with an inlet of the suction blower by means of a duct, and a dirt collecting receptacle disposed under the separator, in which the cleaning machine sucks dirt such as fallen leaves and dust together with air by the sucking force generated by rotation of the engine of the suction blower and collects it into the receptacle by separating it from the air by the separator.”
“The separator comprises a main separator for separating relatively large dirt such as fallen leaves and a subseparator for separating relatively small dirt such as dust contained in the air which has passed through the main separator. The subseparator comprises a plurality of centrifugal dust separators.”
“In this case, it is preferable that the amount of the air flow of the first side stream is reduced as small as possible, because when the dust in the first side is caught in an auxiliary dust bag, the small amount of the air is easy to pass the bag, or when the dust is discharged outside without the auxiliary dust bag, the small amount of the air flow will not spread the dust so much. It is therefore preferable that the amount of the air flow of the first side stream is to be smaller as far as the air flow is sufficient to carry the dust. Therefore, in view of this the second embodiment is so constructed as to further divide the first side stream into the second main and side streams, in which the second main stream flows out separately or together with the first main stream, and the second side stream whose amount is reduced to 20 percent of that of the first side stream, that is 4 percent of the amount of the air from the main separator carries the dust.”
“The construction of each of the centrifugal dust separators 70’ is the same as that of the centrifugal dust separators 70 of the first embodiment.”
“The present invention relates to a cyclone dust-collecting device employed, for example, in a vacuum cleaner; and the aim of the present invention is to provide a multi-cyclone dust collecting device which is able to collect even fine detritus by carrying out the operation of collecting detritus a plurality of times.”
“The present invention relates to an electric cleaner which is capable of sucking dust by using a double cyclone device as a dust capturing means. More particularly, the present invention relates to an electric cleaner which is provided with a substantially compact double cyclone device, thereby preventing the size thereof from being unnecessary bulk[y].”
“Even if the air flows within the intermediate cover 11 through the turn guide pipe 17, a predetermined amount of dust still remaining in the air is caught by means of the fine filter 18.”
“It is occasionally said that there cannot be clear and unmistakable directions to do something which is described as optional. I do not agree: to describe the thing as optional is to describe the thing. It is rather like the disclosure of something as adjustable: it necessarily also discloses something that is not adjustable—see Gillette Safety Razor Co v Anglo-American Trading Co Ltd(1913) 30 RPC 465 .”
“If the claim were valid it would cover one of the alternatives explicitly taught by the citation.”
“(1) (a) Identify the notional ‘person skilled in the art’; (b) Identify the relevant common general knowledge of that person; (2) Identify the inventive concept of the claim in question or if that cannot readily be done, construe it; (3) Identify what, if any, differences exist between the matter cited as forming part of the ‘state of the art’ and the inventive concept of the claim or the claim as construed; (4) Viewed without any knowledge of the alleged invention as claimed, do those differences constitute steps which would have been obvious to the person skilled in the art or do they require any degree of invention?” (b) Identify the relevant common general knowledge of that person; (2) Identify the inventive concept of the claim in question or if that cannot readily be done, construe it; (3) Identify what, if any, differences exist between the matter cited as forming part of the ‘state of the art’ and the inventive concept of the claim or the claim as construed; (4) Viewed without any knowledge of the alleged invention as claimed, do those differences constitute steps which would have been obvious to the person skilled in the art or do they require any degree of invention?”
"The question of obviousness must be considered on the facts of each case. The court must consider the weight to be attached to any particular factor in the light of all the relevant circumstances. These may include such matters as the motive to find a solution to the problem the patent addresses, the number and extent of the possible avenues of research, the effort involved in pursuing them and the expectation of success."
“Such a prejudice may be a merely commercial one (‘this device won't sell’) or it may be a technical one (‘this won't work and it is not worth bothering with’). A 20-year monopoly is conferred for overcoming a prejudice of the second kind, but not for overcoming a commercial prejudice (see Hallen Co v Brabantia (UK) Ltd[1999] RPC 307 (Aldous J)). A technical prejudice must be general: it is not enough that some persons actually engaged in the art at the material time labour under a particular prejudice if a substantial number of others do not. A prejudice which is insufficiently widespread for it properly to be regarded as commonly shared will not, in my view, be attributed to the notional skilled person. As Jacob J put it in Union Carbide v BP (above at p. 16): ‘It is not good enough to show that a matter was known to some but not to others and in particular it is not good enough to show that knowledge (or a prejudice) was confined to one or a limited class of suggested exemplars of the skilled man.’” ‘It is not good enough to show that a matter was known to some but not to others and in particular it is not good enough to show that knowledge (or a prejudice) was confined to one or a limited class of suggested exemplars of the skilled man.’”
“There is no requirement in the EPC or the statute that the specification must demonstrate by experiment that the invention will work or explain why it will work.”
“… there is in my opinion no reason as a matter of principle why, if a specification passes the threshold test of disclosing enough to make the invention plausible, the question of obviousness should be subject to a different test according to the amount of evidence which the patentee presents to justify a conclusion that his patent will work.”
“The obvious response of individuals skilled in the art to a proposal to incorporate three series cyclones into a vacuum cleaner would be - why would I want to do that? - The pressuredrop would be too high. In saying this I mean that the idea of having three stages in series might occur or be suggested in a casual way but that it would be dismissed by the person skilled in the art as not a sensible way forward on the grounds that it would mean too high a pressure drop across the vacuum cleaner.”
“… in the twenty six years between the publication of the original Dyson Patent and the filing of the Samsung Patent the concept of three stage cyclone collection in vacuum cleaners has not been widely discussed, not explicitly patented and no significant commercial position was established by any vacuum cleaner manufacturer using three stage technology of the type under consideration.”
“Opinions of such designs would vary depending upon the experience of the person skilled in the art. At one extreme, many would also regard these as requiring a great deal of extra engineering and so see them as over-complex and expensive. On the other hand, others would recognise that there is a trade-off between the extra dust collection achieved by the second stage and the price played in terms of increased pressure drop and the more expensive fan set. In this latter case, the two stage cyclone would be seen as superior technology but, given the common general knowledge of the person skilled in the art, I do not believe that the idea of simply adding yet another stage would naturally or obviously follow to an uninventive individual.”
“Q. So the amount of headroom or the pressure budget, I think you refer to, is very, very substantial, is it not? A. Yes. Q. As far as I can see, if you happen to be running a product which had a suction of 400 air watts, you could come down to a matter of 150-200 and still have a commercial product? A. Or you could clean someone's room and use less energy. It is a budget for you to spend as you will. Q. I am sorry? A. It is a budget of pressure for you spend as you will.”
“5.1 In paragraphs 3-4 to 3-6 of his first report, Professor Allen comments on the skilled person’s response to the idea of using three stages of cyclonic separation in a vacuum cleaner. The primary basis for these comments is a suggestion that the skilled person would consider the pressure drop across three stages of cyclone to be too high. I disagree with this suggestion. The skilled person would be well aware that a third stage of cyclones has the potential to improve the separation efficiency of the whole system. 5.2 As I have mentioned in paragraph 3.9 of my first expert report, and explained in a little more detail in paragraph 3.10, pressure drop across a cyclone system can be traded against separation efficiency by increasing the inlet and outlet areas in the first and second stages. The skilled person would know this because the same issue had been resolved during the development of two stage cyclones. Taking the cyclonic system as a whole, the skilled person would know how to make adjustments so that the total pressure drop would be acceptable. The skilled person would know that there would be no need to use a more powerful fan.”
“Q. Adding an additional stage of cyclone separation -- I think we have done this -- without more, must increase the pressure drop. A. Yes. If you simply add it, yes, it will. Q. The skilled person would not, therefore, add an additional stage of cyclone separation unless he believed he would gain an appreciable benefit to make up for the additional pressure drop? A. Yes, it is a trade-off between pressure, the separation efficiency and how much suction power and cleaning ability you get at the hose in the vacuum cleaner. Q. I think we have already covered this. At page 8 of your report, the short paragraph 3.9. A. Yes. Q. You have already said, have you not, that you can compensate using, changing the inlet and outlet areas but there comes a limit on how much you can do that? A. Yes. Q. If you do compensate using the inlet and outlet areas you will of course change the collection efficiency? A. Yes. Q. However much you tune that new additional cyclone, you cannot eliminate its pressure drop entirely? A. No, you cannot. Q. If you are trying to get comparable pressure drop, what you would need to do is tune the other cyclones that were already there, altering their efficiency, so that overall you can reduce the pressure drop? A. It depends. If you had a very highly powerful vacuum cleaner in the first place that had a lot of suction power and you were prepared to make it have a lower suction power, then you could not necessarily tune the other cyclones, you could add one.”
“Mr Wyand submitted that it is the task of the court to determine what Saito clearly and distinctly taught the skilled person at the priority date, not what can be read out of Saito by the application of hermeneutical stress. This admirable phrase concisely describes the process of squeezing a document to extract every last drop of meaning. The submission is correct: to anticipate, a document must contain a clear description of, or clear and unmistakable directions to do or make, something within the claim: see General Tire v Firestone[1972] RPC 457 . When considering obviousness, on the other hand, ambiguities in the disclosure of the document may be obviously capable of resolution in a particular way without the exercise of ingenuity: but it is not legitimate to try to resolve obscurity by an exercise in imaginative reconstruction to ascertain what it was that the patentee must have been trying to describe.”
“The decision as to whether there was an extension of disclosure must be made on a comparison of the two documents read through the eyes of a skilled addressee. The task of the Court is threefold: (1) To ascertain through the eyes of the skilled addressee what is disclosed, both explicitly and implicitly in the application. (2) To do the same in respect of the patent [as proposed to be amended]. (3) To compare the two disclosures and decide whether any subject matter relevant to the invention has been added whether by deletion or addition. The comparison is strict in the sense that subject matter will be added unless such matter is clearly and unambiguously disclosed in the application either explicitly or implicitly.”
“4. In Richardson-Vicks' Patent[1995] RPC 568 at 576 I summarised the rule in a single sentence: ‘I think the test of added matter is whether a skilled man would, upon looking at the amended specification, learn anything about the invention which he could not learn from the unamended specification.’ I went on to quote Aldous J in Bonzel. His formulation is helpful and has stood the test of time. 5. The reason for the rule was explained by the Enlarged Board of Appeal of the EPO in G1/93 ADVANCED SEMICONDUCTOR PRODUCTS/Limiting feature [1995] EPOR 97 at [Reasons 9]: ‘With regard to Article 123(2) EPC, the underlying idea is clearly that an applicant shall not be allowed to improve his position by adding subject-matter not disclosed in the application as filed, which would give him an unwarranted advantage and could be damaging to the legal security of third parties relying upon the content of the original application.’ 6. Mr Richard Arnold QC provided a clear articulation as to how the legal security of third parties would be affected if this were not the rule: ‘The applicant or patentee could gain an unwarranted advantage in two ways if subject-matter could be added: first, he could circumvent the "first-to-file" rule, namely that the first person to apply to patent an invention is entitled to the resulting patent; and secondly, he could gain a different monopoly to that which the originally filed subject-matter justified.’ 7. Kitchin J has recently helpfully elaborated upon the Bonzel formulation in European Central Bank v Document Security Systems[2007] EWHC 600 (Pat) ,26th March 2007 : ‘[97] A number of points emerge from this formulation which have a particular bearing on the present case and merit a little elaboration. First, it requires the court to construe both the original application and specification to determine what they disclose. For this purpose the claims form part of the disclosure (s.130(3) of the Act), though clearly not everything which falls within the scope of the claims is necessarily disclosed. [98] Second, it is the court which must carry out the exercise and it must do so through the eyes of the skilled addressee. Such a person will approach the documents with the benefit of the common general knowledge. [99] Third, the two disclosures must be compared to see whether any subject matter relevant to the invention has been added. This comparison is a strict one. Subject matter will be added unless it is clearly and unambiguously disclosed in the application as filed. [100] Fourth, it is appropriate to consider what has been disclosed both expressly and implicitly. Thus the addition of a reference to that which the skilled person would take for granted does not matter: DSM NV's Patent[2001] RPC 25 at [195]-[202]. On the other hand, it is to be emphasised that this is not an obviousness test. A patentee is not permitted to add matter by amendment which would have been obvious to the skilled person from the application. [101] Fifth, the issue is whether subject matter relevant to the invention has been added. In case G1/93, Advanced Semiconductor Products, the Enlarged Board of Appeal of the EPO stated (at paragraph [9] of its reasons) that the idea underlying Art. 123(2) is that that an applicant should not be allowed to improve his position by adding subject matter not disclosed in the application as filed, which would give him an unwarranted advantage and could be damaging to the legal security of third parties relying on the content of the original application. At paragraph [16] it explained that whether an added feature which limits the scope of protection is contrary to Art. 123(2) must be determined from all the circumstances. If it provides a technical contribution to the subject matter of the claimed invention then it would give an unwarranted advantage to the patentee. If, on the other hand, the feature merely excludes protection for part of the subject matter of the claimed invention as covered by the application as filed, the adding of such a feature cannot reasonably be considered to give any unwarranted advantage to the applicant. Nor does it adversely affect the interests of third parties. [102] Sixth, it is important to avoid hindsight. Care must be taken to consider the disclosure of the application through the eyes of a skilled person who has not seen the amended specification and consequently does not know what he is looking for. This is particularly important where the subject matter is said to be implicitly disclosed in the original specification.’ 8. When amendment of a granted patent is being considered, the comparison to be made is between the application for the patent, as opposed to the granted patent, and the proposed amendment (see the definition of ‘additional matter’ in s.76(1)(b)). It follows that by and large the form of the granted patent itself does not come into the comparison. This case was to some extent overcomplicated by looking at the granted patent, particularly the granted claim 1. 9. A particular, and sometimes subtle, form of extended subject matter (what our Act calls ‘additional matter’) is what goes by the jargon term ‘intermediate generalisation’. Pumfrey J described this in Palmaz's European Patents[1999] RPC 47 , 71 as follows: ‘If the specification discloses distinct sub-classes of the overall inventive concept, then it should be possible to amend down to one or other of those sub-classes, whether or not they are presented as inventively distinct in the specification before amendment. The difficulty comes when it is sought to take features which are only disclosed in a particular context and which are not disclosed as having any inventive significance and introduce them into the claim deprived of that context. This is a process sometimes called “intermediate generalisation”.’” ‘I think the test of added matter is whether a skilled man would, upon looking at the amended specification, learn anything about the invention which he could not learn from the unamended specification.’ I went on to quote Aldous J in Bonzel. His formulation is helpful and has stood the test of time. Appeal of the EPO in G1/93 ADVANCED SEMICONDUCTOR PRODUCTS/Limiting feature [1995] EPOR 97 at [Reasons 9]: ‘With regard to Article 123(2) EPC, the underlying idea is clearly that an applicant shall not be allowed to improve his position by adding subject-matter not disclosed in the application as filed, which would give him an unwarranted advantage and could be damaging to the legal security of third parties relying upon the content of the original application.’ ‘The applicant or patentee could gain an unwarranted advantage in two ways if subject-matter could be added: first, he could circumvent the "first-to-file" rule, namely that the first person to apply to patent an invention is entitled to the resulting patent; and secondly, he could gain a different monopoly to that which the originally filed subject-matter justified.’ ‘[97] A number of points emerge from this formulation which have a particular bearing on the present case and merit a little elaboration. First, it requires the court to construe both the original application and specification to determine what they disclose. For this purpose the claims form part of the disclosure (s.130(3) of the Act), though clearly not everything which falls within the scope of the claims is necessarily disclosed. [98] Second, it is the court which must carry out the exercise and it must do so through the eyes of the skilled addressee. Such a person will approach the documents with the benefit of the common general knowledge. [99] Third, the two disclosures must be compared to see whether any subject matter relevant to the invention has been added. This comparison is a strict one. Subject matter will be added unless it is clearly and unambiguously disclosed in the application as filed. [100] Fourth, it is appropriate to consider what has been disclosed both expressly and implicitly. Thus the addition of a reference to that which the skilled person would take for granted does not matter: DSM NV's Patent[2001] RPC 25 at [195]-[202]. On the other hand, it is to be emphasised that this is not an obviousness test. A patentee is not permitted to add matter by amendment which would have been obvious to the skilled person from the application. [101] Fifth, the issue is whether subject matter relevant to the invention has been added. In case G1/93, Advanced Semiconductor Products, the Enlarged Board of Appeal of the EPO stated (at paragraph [9] of its reasons) that the idea underlying Art. 123(2) is that that an applicant should not be allowed to improve his position by adding subject matter not disclosed in the application as filed, which would give him an unwarranted advantage and could be damaging to the legal security of third parties relying on the content of the original application. At paragraph [16] it explained that whether an added feature which limits the scope of protection is contrary to Art. 123(2) must be determined from all the circumstances. If it provides a technical contribution to the subject matter of the claimed invention then it would give an unwarranted advantage to the patentee. If, on the other hand, the feature merely excludes protection for part of the subject matter of the claimed invention as covered by the application as filed, the adding of such a feature cannot reasonably be considered to give any unwarranted advantage to the applicant. Nor does it adversely affect the interests of third parties. [102] Sixth, it is important to avoid hindsight. Care must be taken to consider the disclosure of the application through the eyes of a skilled person who has not seen the amended specification and consequently does not know what he is looking for. This is particularly important where the subject matter is said to be implicitly disclosed in the original specification.’ 8. When amendment of a granted patent is being considered, the comparison to be made is between the application for the patent, as opposed to the granted patent, and the proposed amendment (see the definition of ‘additional matter’ in s.76(1)(b)). It follows that by and large the form of the granted patent itself does not come into the comparison. This case was to some extent overcomplicated by looking at the granted patent, particularly the granted claim 1. 9. A particular, and sometimes subtle, form of extended subject matter (what our Act calls ‘additional matter’) is what goes by the jargon term ‘intermediate generalisation’. Pumfrey J described this in Palmaz's European Patents[1999] RPC 47 , 71 as follows: ‘If the specification discloses distinct sub-classes of the overall inventive concept, then it should be possible to amend down to one or other of those sub-classes, whether or not they are presented as inventively distinct in the specification before amendment. The difficulty comes when it is sought to take features which are only disclosed in a particular context and which are not disclosed as having any inventive significance and introduce them into the claim deprived of that context. This is a process sometimes called “intermediate generalisation”.’”
“The second passages 360 are formed such that the air exiting from each second cyclone chamber 320 is directed towards the associated pair of third chambers 330.”
“The appellant seeks to extract an otherwise unidentified feature (nowhere suggested to have inventive significance) which appears from a drawing of one of the preferred embodiments of the invention, and to insert it into the claim, without taking any other features of that embodiment. What the appellant is thereby doing is what Pumfrey J said was not permitted in the Palmaz case, namely to effect a so-called intermediate generalisation, that is, to extract a feature (which was neither remarked on in the specification nor of significance to the person skilled in the art) of one of the preferred embodiments of the invention and insert it into a claim, while ignoring the other features of that embodiment.”