T 2074/14 23-01-2018

Reasons for the Decision

Main request

1. Article 100(b) EPC 1973

The ground for opposition under Article 100(b) EPC 1973 is prejudicial to the maintenance of the patent as granted.

1.1 Claim 1 as granted includes the feature:

'a position at which the moving velocity of the footstep rollers (5) comes to Vo as a result of reducing from Vt is represented by a reference positions (sic)'.

The patent as a whole however provides no teaching as to how the reference position(s) can be determined, be this by simulation, measurement or calculation. Similarly, such teaching is not available to the skilled person from common general knowledge. Such reference positions are fundamental for the invention to be carried out since the curved part (13) of the footstep guide rail (3) 'is positioned between one reference position in the vicinity of the drive sprocket (9) and another reference position adjoining the one reference position.' Thus, without being able to determine the reference positions, the invention cannot be carried out by a person skilled in the art.

1.2 It is noted first that the reference positions themselves are physical positions of the footstep chain in the conveyer apparatus, these positions however being defined as those where the footstep roller velocity reaches Vo (the average footstep roller velocity) having reduced from Vt (the velocity of the footstep roller at the pitch circle of the drive sprocket). It is also not a matter of dispute between the parties that every footstep conveyer apparatus driven by a chain interacting with a drive sprocket will be subject to the polygonal effect, and that the footstep roller velocity will thus fluctuate between maximum and minimum values. As a consequence, therefore, the footstep rollers will reach the average velocity Vo on reducing from Vt at several positions along the chain path on every such conveyer apparatus which has not been altered by a compensation means. Nonetheless, how to establish the location of the claimed reference positions in the claimed conveyer apparatus is not taught in the patent.

1.3 As regards the respondent's contention that the location of the reference positions could be simulated, no indication of how such a simulation could be performed is to be found either in the patent or in the written submissions of the respondent. In response to the preliminary opinion of the Board which addressed the lack of any information as to how e.g. a simulation could be performed, the respondent offered no further argument either in writing or at the oral proceedings. The Board thus sees no reason to diverge from its preliminary opinion in this regard and the Board thus confirms its preliminary opinion that the patent fails to disclose how the reference positions can be established through simulation.

1.4 The respondent's argument that the reference positions could be established by measurement during the design phase of the apparatus is not convincing. In order to empirically determine the reference positions, the instantaneous velocity of the footstep rollers would need to be measurable so that the positions in which this velocity reduced to the average velocity could be identified.

1.4.1 Such a physical measurement of the exact positions at which the average velocity is reached would not be readily possible on an operating conveyer apparatus according to claim 1. Such an apparatus would not behave in an easily predictable, static manner as might be suggested when relying on purely theoretical considerations. Rather, mechanical imperfections in the apparatus (tolerances in the chain-links; the mass and inertia of the footsteps; irregularities in the drive sprocket etc.) would result in the footstep chain's movement diverging from the theoretical behaviour with obvious delays in the theoretical acceleration and deceleration of the chain. These delays would occur through inter alia the inertia of the overall conveying system retarding movement, and/or any play in the chain links causing a hiatus in the movement being immediately transferred from link to link in the chain. As a consequence, even if the instantaneous velocity of the footstep rollers could be ascertained by way of high speed imaging, the precise locations of the reference positions would not be fixed positions in time along the footstep chain due at least to the above identified mechanical imperfections. Which aspects should be taken into account to establish the specific moment at which the velocity should be measured is not a simple matter and no information on this has been disclosed.

1.4.2 The respondent's contention that the chain links interacting with the drive sprocket was a repeating mechanical interaction which would thus produce a stationary system of reference positions is not convincing. It can be accepted in a theoretical, perfect system, with no inertial effects or tolerances in linkages, that a stationary conveyer system would result in which it could be possible to identify and accurately locate the reference positions. However, with it being argued that the reference positions could be empirically determined on an actual conveyer apparatus, this would be subject to inertial and tolerance effects which would necessarily cause the footstep chain movement to diverge from the theoretical, thus making a repeatable determination of the reference positions by measurement impossible.

1.4.3 The respondent's argument that it could surely not be required to have to explicitly provide a way of measuring an intrinsically present feature is also not accepted. The intrinsic presence of reference positions along the footstep chain is not questioned; such reference positions doubtlessly exist for the claimed apparatus. What is not possible is for the skilled person on the basis of the teaching of the patent as a whole, by measurement from an actual conveyer apparatus with all its mechanical imperfections causing motion diverging from the theoretical, to determine the locations of the claimed reference positions.

1.4.4 In summary therefore, the skilled person would be unable to identify the reference positions by measurement.

1.5 The respondent's argument that the skilled person could establish the reference positions by calculation is not accepted.

1.5.1 The respondent's reference to paragraphs [0048] and [0049] of the patent in order to enable Vo to be calculated is not convincing. The formula in this paragraph identifies small velocity unevenness of the footstep rollers being defined by (Vo-romegasin(omegat+phi)), yet the patent fails to identify what physical quantity 'phi' represents. The respondent indicated this to be a constant 'phase shift', yet this knowledge provides no resultant ability to calculate the value of Vo. As such, this formula for velocity unevenness does not guide the skilled person to determining the average footstep roller velocity Vo which would be required for calculating the claimed reference positions. A reference by the respondent to 'excel sheets' used by the proprietor in order to calculate the reference positions is also not helpful, since the sole calculation disclosed in the patent in this regard is that for the velocity unevenness cited above, which fails to provide the skilled person with a method of calculating the average velocity Vo and thus also the reference positions.

1.5.2 The respondent's reference to OT8 as proving that the skilled person's general knowledge included calculation of compensation curves and thus the claimed reference positions is not accepted. OT8 is a document prepared by the appellant and, according to it, based on the kinematic model of D6, describing a quantitative mathematical model for calculating the position and shape of the compensation curve for the claimed apparatus in the opposed patent. The Board finds that, as also argued by the appellant, based on the information given in the patent and the skilled person's common general knowledge, significant efforts would still be required to derive the reference positions by calculation (see pages 1 to 8 of OT8). Lacking any guidance whatsoever in the patent, the considerable derivative effort through calculation required, as evidenced by OT8, is seen to constitute an undue burden to the skilled person when trying to carry out the invention.

1.5.3 As regards D6, which also disclosed how reference positions might be calculated, it has to be noted that this document is not mentioned in the description of the patent in suit. The respondent's argument that D6 could be seen as evidence of the skilled person's common general knowledge is not accepted. Indeed, contrary also to the finding of the opposition division in its decision, patent documents cannot normally be considered as evidence of the skilled person's common general knowledge and thus contribute to the sufficiency of disclosure of the patent in suit (see e.g. T171/84 Reasons 5; T 580/88, Reasons 2.3), rather common general knowledge is represented by basic handbooks and textbooks on the subject in question. Information that has to be found through a search does not belong to common general knowledge. In the present case, therefore, the respondent's reliance on D6 as an indication of how the skilled person would be able to calculate the claimed reference positions is not persuasive. It is also noted that D6 was published in 1985 yet the respondent had failed, despite reference to the lack by the appellant, to cite a text book which could unequivocally prove the calculation of the reference positions to be common general knowledge.

1.5.4 The respondent's contention that the polygonal effect was a very specific phenomenon thus understood by everyone working in the field also fails to persuade that D6 should thus be seen as disclosing the common general knowledge of the skilled person. As found above, patent documents are not normally considered to evidence the common general knowledge of the skilled person, this rather being the content of textbooks which, even in this limited field relating specifically to the polygonal effect, have notably not been cited in support of the respondent's case.

1.5.5 The respondent's argument that the similarity between Figs. 3 and 4 of the patent in suit and Fig. 4 of D6 would have led the skilled person to the content of D6 is also not convincing. Even given the similarity in the compensation curves depicted in D6 and the patent, the skilled person is not considered to have the content of D6 as its common general knowledge, and would not expect to have to carry out a search of patent documents in the field in order to be able to carry out the invention insufficiently disclosed in the patent in suit.

1.5.6 The respondent's further argument that the exact location of the reference positions was not essential due to the asymptotic nature of the compensation curve in its extremities also fails to convince the Board to alter its conclusion. Such an argument addresses the clarity of precisely where a reference position is to be defined. Yet the issue in question is whether the reference positions can be calculated at all by the skilled person based on the disclosure of the patent in suit in combination with common general knowledge, the answer to which is negative as detailed in the foregoing.

1.5.7 The respondent's reference to the extensive bibliography of M10078 with the argument that the polygon effect and its mitigation was thus common general knowledge is not accepted. While it cannot be questioned that numerous references in the bibliography included polygonal action in their title, this solely provides evidence that the polygonal effect is well known. This is not contested. No argument was however presented by the respondent that these references would provide the skilled person with guidance as to how to calculate the location of the claimed reference positions, nor indeed can any such guidance be ascertained without the filing of a specific document detailing such calculation.

1.5.8 In summary therefore, based on the information before it, the Board can only conclude that the skilled person would be unable to identify the reference positions by calculation.

1.6 With the skilled person being unable to establish the location of the reference positions by simulation, measurement or calculation, it follows that the ground for opposition under Article 100(b) EPC 1973 prejudices maintenance of the patent as granted.

Auxiliary requests

2. Article 83 EPC 1973

2.1 Claim 1 of each of the auxiliary requests includes the feature objected to in the main request that:

'a position at which the moving velocity of the footstep rollers (5) comes to Vo as a result of reducing from Vt is represented by a reference position'.

None of the features added to the respective claim 1 of any of the requests is found to change the conclusion on insufficiency of the main request. The respondent also did not contest that the same finding would apply to each of the auxiliary requests and opted to provide no further arguments in defence of these requests. The Board thus concludes, for the same reasons as those for the main request, that the amended form of the patent according to each of the auxiliary requests fails to disclose the invention in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art.

2.2 Each auxiliary request thus fails to meet the requirements of Article 83 EPC 1973. The auxiliary requests are therefore not allowable.