Dayco Europe SRL v Gates Unitta Asia Company & Ors

I have before me an application by the claimant for permission to call two experts, one with expertise in the field of mechanical engineering and the other with expertise in the field of textiles. The application is resisted by the defendant patentees.

There is clearly a duty upon the court to restrict expert evidence to that which is reasonably required to resolve the proceedings. The invention, the subject of the patent in suit, relates to a toothed belt for power transmission. It seeks to provide a solution to the problem created by engine rooms being subjected to high temperatures with the result that tooth belts are required to have sufficient durability in the resulting hot atmosphere. The solution to this problem described in the patent is a particular woven fabric which is processed on to the meshing face of the toothed belt, characterised in that the woven fabric has its longitudinal yarns extending in the longitudinal direction of the toothed belt, that it is formed of covered yarns, each of which is prepared by turning a high tensile strength and heat resistant fiber yarn on an elastic core yarn and then by further turning a synthetic yarn thereon.

It is, I think, apparent that the skilled team to whom the patent is directed, must include expertise in the fields of both mechanical engineering and textile technology. The defendants have, to their credit, identified an expert who they believe has expertise in both areas and can accordingly address all the issues arising in relation to the allegation of obviousness of the invention. The claimant has not been so fortunate, despite efforts which its counsel, Mr. Cuddigan, has explained to me in the course of the hearing this morning have been made. It has, however, identified one expert in the textile field, Mr. Ellis, and another in the engineering field, Professor Childs. Each of these proposed experts has explained that, although he has expertise in his own area, he has none in the other. It is for this reason that the claimant seeks permission to call both.

Mr. Abrahams, on behalf of the defendants, says that permitting the claimant to call two expert witnesses will unnecessary lengthen the trial and place the defendants in a difficult position because it will mean that the case is not conducted on a level playing field and may create a perception of injustice. These are, of course, serious points to which I must give due regard. However, at the end of the day, I believe that the interests of justice demand that I accede to the claimant's application in the circumstances which I have described.

I am confident that, in the light of the observations I have made during the course of this hearing, the claimant and its experts will take very great care to ensure that there is no duplication of evidence and that the reports of the experts are no longer than they need be. Bearing in mind that each of these experts has professed to have no expertise in the field in which the other is experienced, I am doubtful that giving permission to the claimant to call both will unduly lengthen the trial, because each will of course be unable to answer any questions in the area of expertise of the other. Moreover, I have no doubt that the trial judge will conduct the trial in such a way that the risk of any perception of there not being a level playing field will be minimised if not eliminated entirely. Accordingly I propose to allow the application.