Both the patent proprietor and the opponent filed an appeal after the Opposition Division had maintained the patent-in-suit in amended form.
Claim 1 of the main request before the Board read:
1. A mixer (100, 200, 300, 400, 500, 600) for producing a paste by mixing components, comprising a housing (110, 210, 310, 410, 510, 610) having a longitudinal axis, a rear end (111, 211, 311, 411, 511) and a front end (112, 212, 312, 412, 512) provided with a discharge opening (113, 213, 313, 413, 513); anda mixing chamber (120, 220, 320, 420, 520) formed in said housing and having an entry side (121) facing said rear end of said housing; characterized in thatsaid mixer is adapted such that the initial amount of at least one of said components entering said mixing chamber or the initial amount of mixture being prepared in said mixing chamber is diverted from said discharge opening, and the subsequent content of said mixing chamber is extrudable from said discharge opening; and wherein said mixer comprises a reservoir (140, 240, 340, 440, 540, 640) for storing said initial amount.
The Board found this subject-matter to be insufficiently disclosed.
I found the decision interesting because it discusses sufficiency of disclosure of subject-matter defined via its function.
Requirements for sufficiency of disclosure
[1.1] It is established jurisprudence of the boards of appeal that the requirements for sufficiency of disclosure are met only if the invention as defined in the claims can be performed by a person skilled in the art in the whole area claimed without undue burden, using common general knowledge and having regard to further information given in the patent in suit (see T 435/91 [2.2.1]).
[1.2] That principle applies to any invention irrespective of the way the claims are defined, be it by way of a structural or a functional feature.
The peculiarity of the functional definition of a technical feature resides in the fact that it is defined by means of its effect. That mode of definition comprises an indefinite and innumerable host of possible alternatives of diverse structure, which is acceptable as long as all these alternatives achieve the desired result and are available to the skilled person. This reflects the general principle in law whereby the protection sought must match the technical contribution made by the disclosed invention to the state of the art. Therefore, it has to be established whether or not the patent in suit discloses a technical concept fit for generalisation which makes available to the skilled person the host of variants encompassed by the functional definition of a technical feature as claimed (see T 1063/06 ).
In other words, if, in the patent in suit, gaps in information and/or a lack of guidance can be identified, there is insufficiency of disclosure.
Information regarding technical details
[1.3] Claim 1 relates to a mixer for producing a paste by mixing components.
Neither the paste nor the components are further defined in claim 1. A paste is not a well-defined expression for a solid dispersion in a liquid that has a viscous consistency.
The mixer should make it possible to produce a paste (of any type) by mixing components (of any type). As admitted by the parties, it is known to the skilled person that a paste itself can vary considerably in viscosity. The components used for producing the paste can vary even more.
[1.4] Claim 1, which is directed to a mixer, i.e. an apparatus, is characterised by process features that define the “result to be achieved” (functional definition):
“said mixer is adapted such that the initial amount of at least one of said components entering said mixing chamber or the initial amount of mixture being prepared in said mixing chamber is diverted from said discharge opening, and the subsequent content of said mixing chamber is extrudable from said discharge opening; and wherein said mixer comprises a reservoir for storing said initial amount”.
[1.5] In the present case, it has to be analyzed whether the skilled person would be enabled to construct the different variants of mixers falling within the scope of claim 1, depending on the type of paste that is to be obtained and on the components that are to be used for producing the paste.
This means that, for specific components, the mixer has to be constructed such that the desired result can be achieved. The skilled person would understand that this result is achieved if the “initial amount” of either the mixture or a component that has entered the mixing chamber is diverted and stored in a reservoir such that the subsequent amount can pass by and exit the mixer prior to the “initial amount”.
[1.6] Since neither the paste that is produced nor the components that are used for its production are defined, many different variants of mixers may have to be constructed to ensure that for each type of component the desired result is obtained.
To obtain this result, the mixer must contain some structural features that ensure that
- the “initial amount” enters the reservoir and
- the subsequent amount does not mix with the “initial amount” present in the reservoir and does not displace the “initial amount” present in the reservoir.
Gaps in information regarding the initial amount
[1.7] The skilled person would have to know first what is understood by the “initial amount”. The patent in suit teaches that the “initial amount” that should not be dispensed is such that it allows the subsequent amount to have the desired quality (see for example column 2, lines 33 and 34: “desired ratio of first and second components”; column 3, lines 8 and 9: “avoided that a mixture has an undesirable mixing ratio”; column 3, lines 25 and 26: “prevented from using the first amount of mixture potentially having an undesirable mixing ratio”). As admitted by [the patent proprietor], the “initial amount” is thus indirectly defined via the quality of the “subsequent amount”.
The skilled person would have to analyse the paste exiting the mixer and to decide whether it is up to his expectations. Such an analysis seems to be within the competence of the skilled person, since it is standard practice in the field to analyse the quality of products.
[1.8] However, to be able to analyse only the “subsequent amount”, the skilled person would have to ensure that the “initial amount” is indeed stored away and does not exit together with the “subsequent amount”. This can only be achieved if the “subsequent amount” does not displace the “initial amount” from the reservoir and does not mix with the “initial amount”.
Gaps in information regarding the components, the reservoir, the mixer and the mixing process.
[1.9] As admitted by [the patent proprietor] during the oral proceedings, this displacement mentioned above under item [1.8] depends on the viscosities of the different components, on the size of the reservoir and on the diameter of the reservoir. It is the Board’s opinion that other factors such as the size and form of the mixer itself, the openings, the position and inclination of the reservoir, the time and speed of mixing, and the quantity of the “subsequent amount” will also impact on the storage of the “initial amount”. In fact, the construction of the mixer itself influences the fluid dynamics inside the mixer and mixing chamber and this has to be taken into consideration in the construction of a reservoir for the “initial amount”.
[1.10] The patent in suit is completely silent on the type of reservoir to be chosen for mixing specific components that might range from almost aqueous to very viscous or even powdery. The patent in suit only discloses that the paste to be obtained could be a dental impression mass […], but fails to give any indication on the viscosity of such masses or on the components used for making such masses. The skilled person would know that there is a large variety among dental impression masses both in viscosity and in composition, as acknowledged by [the patent proprietor] during oral proceedings. Furthermore, claim 1 is not limited to a mixer for such dental impression masses.
[1.11] The patent in suit contains many figures that describe different embodiments. There is not a single indication what components were mixed in the illustrated embodiments, what viscosities they are suitable for, what mixing speed and time were appropriate and what the real dimensions of the mixing chamber and the reservoir were. Thus, the skilled person could not deduce from the patent that a specific embodiment is perfectly suitable for use with a specific type of component and/or mixture. He could not recognise that the depicted reservoirs (figures 1 to 11) always store the “initial amount” independently of the type of components introduced into the mixer.
No suitable evidence to fill the gaps in information
[1.12] [The patent proprietor] provided with its letter of 24 June 2013 an experimental set-up that was supposed to provide evidence that the “initial amount” is indeed stored in the reservoir and not displaced, by the “subsequent amount”. Said experiment was conducted with a mixer as shown in the figure on page 1 of the appendix to said letter. Such a mixer is not illustrated in the patent in suit and cannot be considered as a mixer according to figure 9 of the patent in suit, since its form is tapered and it has several discharge openings, contrary to the mixer of figure 9. Thus, the fact that neither the dimensions of the mixer used in the experimental set-up nor the dimensions of the mixer according to figure 9 are given is no longer of relevance.
[1.13] The mixer used in the experimental set-up cannot be designated without any doubt as a mixer according to claim 1 of the patent in suit, since the orange base material was prefilled in the reservoir and did not enter the mixing chamber as required by claim 1. Furthermore, the “initial amount” was assumed to be the amount filling the reservoir so that the skilled person would have to have already gained knowledge from somewhere about the amount that needed to be discarded (stored away). The mixer was prefilled with a specific orange base component having a high viscosity while a hardenable paste with a lower viscosity was forced to flow through the mixing chamber. In fact, it seems that the paste (blue/violet) was not produced by mixing components in the mixer, but already entered the mixer as such (blue/violet). In that very specific set-up, most of the so-called “initial amount” was not displaced from the reservoir while the “subsequent amount” exited through the discharge opening. All the skilled person would learn from said experiment is that under specific conditions an “initial amount” already prefilled in the reservoir is not substantially displaced by the “subsequent amount”. However, there is no information about how the skilled person would arrive at these specific conditions. The skilled person would not know whether said mixer is a mixer for producing a paste by mixing components, since the components are not mixed in the mixer. In addition, said experiment does not fulfil the following condition:
“adapted such that the initial amount of at least one of said components entering said mixing chamber or the initial amount of mixture being prepared in said mixing chamber is diverted from said discharge opening, and the subsequent content of said mixing chamber is extrudable from said discharge opening”.
Actually, the “initial amount” of the first component did not enter the mixing chamber and was not diverted into the reservoir.
[1.14] The experimental set-up shown in this example is not taught in the patent in suit, since neither such a specific mixer nor the specific components used are disclosed.
[1.15] The experimental set-up seems to be based on specific knowledge of [the patent proprietor] for which there is no evidence that it belongs to the skilled person’s general knowledge.
[1.16] The Board is not convinced that the same result would be achieved with the mixer shown in the experimental set-up if the first component was rather fluid and had a lower viscosity than the second component. In such a case the mixture would at least partially displace the “initial amount” from the reservoir so that the “initial amount” would not really be stored. The same would happen if the mixture formed in the mixing chamber was a fluid paste with rather low viscosity.
In addition, it is not sure that the same observations would be made if the reservoir was not prefilled, but empty, and the “initial amount” first needed to be captured.
The Board is convinced that there are many possible mixtures or combinations of components for which it cannot easily be ensured that the subsequent amount exits through the discharge opening before the “initial amount”.
Research programme to fill the gaps in information
[1.17] The skilled person trying to construct the mixer according to claim 1 would thus be confronted with the following major tasks
- ensuring that the reservoir is such that the “initial amount” is correctly chosen and captured
- ensuring that the “initial amount” present in the reservoir is not displaced by the “subsequent amount”.
[1.18] These two tasks may require different, possibly opposing, characteristics of the reservoir, since a large “initial amount” requires a large reservoir while the content can be displaced more easily from a large and wide reservoir. On the other hand, it may be difficult to fill deep and narrow reservoirs, especially if the viscosity of the component or the mixture is high.
[1.19] The Board is of the opinion that the skilled person would be at a complete loss as to how to solve the tasks identified above, since the patent in suit does not mention at all any of the parameters relevant for the solution to each task (e.g. viscosity, size and form of reservoir, size of mixing chamber, position of the reservoir within the chamber, flow rate and speed etc.).
[1.20] What the skilled person would probably need to do would be to start with the components and take a mixer that is available. As admitted by [the patent proprietor], if the mixing of the components did not give the desired result since either the “initial amount” was not chosen such that the subsequent amount had the desired quality and/or the “initial amount” was not correctly stored, then the skilled person would have to start adapting the mixer and repeat the whole procedure again until the desired result was obtained. Alternatively he could change the components and try again with the mixer at hand. The patent in suit is silent as to which direction to take to ensure that success is guaranteed after a few tries. It seems up to the skilled person to establish for which type of components and paste produced the illustrated mixers could be of use.
[1.21] The prior art is not of help either to the skilled person trying to solve the tasks identified in [1.17] above. As explained by [the patent proprietor], the present invention relates to a new concept that helps to ensure that the mixed paste exiting the mixer has the desired quality, wherein the mixture or one component present in the mixing chamber is diverted afterwards to a reservoir. In contrast, the prior art tries to obtain the desired quality by ensuring that the correct mixture enters the mixing chamber, so that no reservoir is foreseen after the mixing chamber. This is illustrated for example by D1 to D7. Therefore, these documents teach a different set-up and cannot be used when trying to construct a mixer according to the new concept. They do not provide any information on the “initial amount” and do not disclose a reservoir according to the present invention so that the skilled person could not find any guidance there on how to ensure that the “initial amount” entering a reservoir is definitely stored there. The prior art indicates that certain types of mixers are especially suitable for components having specific viscosities […]. However, there is no hint for the skilled person that would lead him to success in the present case; he is rather given the confirmation that viscosity of the components is also an important parameter to consider.
[1.22] Consequently, to carry out the claimed invention (i.e. to construct the mixer according to claim 1), the skilled person, in each single case for the many variants falling within the scope of claim 1, would be faced with the problem of determining the suitable mixer features that might allow him to make sure that the “initial amount” is stored such that the subsequent amount exits the mixer and has the desired quality. However, neither the common general knowledge nor the patent in suit provides him with any information that would guide him in a systematic and reliable way towards the required construction that would allow the desired paste to be obtained when starting from specific components. Thus, the skilled person would not have at his disposal any guidance leading necessarily and directly to success through the evaluation of failures that may occur, so that he could only establish by trial and error in each single case whether or not particular features (e.g. size, shape and position of the reservoir) will ensure that the “initial amount” is stored in the reservoir and the subsequent amount exits the mixer. That constitutes an undue burden.
[1.23] In line with T 1358/07 [6.3], the functional definition of the mixer according to the present invention is thus no more than an invitation to perform a research programme in order to find a suitably configured mixer with reservoirs.
[1.24] The objection under A 100(b) is therefore justified for claim 1 of the patent in suit. The main request is not acceptable.
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