European patent application 02785665.7 involved a method of determining the optimum helix angle of a helical formation for a conduit. Claim 1, for example, read as follows:
1. A method of determining the optimum helix angle of a helical formation (4) for a conduit (1), wherein the optimum helix angle is for minimising turbulent flow and dead spots within flow through the conduit (1), the method comprising specifying the internal dimensions of the conduit (1), characterized byThe Examining Division refused the claims under several grounds. One of these was that the claimed method represented a discovery, scientific theory or mathematical method as such (Article 52(2)(a)) or a presentation of information as such (Article 52(2)(d)).
specifying an intended fluid mass flow through the conduit (1);
measuring the pressure drop along, and the turbulent kinetic energy in, a conduit (1) with a helical formation (4) at a range of different helix angles, wherein the conduit (1) has the specified internal dimensions and intended fluid mass flow;
non-dimensionalizing the pressure drop and the turbulent kinetic energy; and
determining the optimum helix angle from plots of curves of the helix angle versus the non-dimensionalized pressure drop and the helix angle versus the non-dimensionalized turbulent kinetic energy.
The Board observed that the present invention, as defined in claim 1, is clearly of a technical character. The problem addressed by the present invention is a technical one. The result of the claimed method, the identification of the optimum helix angle, is undoubtedly a technical result.
The invention, said the Board, enables conduits containing helical formations to be produced in an advantageous manner.
It is not merely a discovery, scientific theory or mathematical method, because the invention is embodied within a method of determining a particular technical matter.
It is not a mere presentation of information, since it involves determining a subject of objective technical significance, namely the optimum helix angle of the helical formation for a conduit.
The invention is not defined solely by presenting a number which has no technical significance. By carrying out the method of the invention, the optimum angle for the helical formation in order to minimize turbulent flow and dead spots within flow through the conduit is determined.
The Board decided there was no need to hold oral proceedings. The case was sent back to the Examining Division with an order to grant the patent.