T 0192/82 (Moulding composition) of 22.03.1984

I. If an article is known as a combination or mixture of components fulfilling known functions, the generation and application of an improved novel component for the same purpose may be patentable as such and also as an improved article incorporating the same. If the component in question forms, on the other hand, part of the state of the art together with its relevant properties, the in- corporation thereof in the same article will be obvious in view of its predictable beneficial effect ("analogous substitution").

II. The skilled man must be free to employ the best means already available for his purposes, although the use of means leading to some expected improvements may well be patentable in relying on an additional effect, provided this involves a choice from a multiplicity of possibilities. The lack of alternatives, in this respect may, therefore, create a "one-way-street" situation leading to predictable advantages which remain obvious in spite of the existence of some unexpected "bonus" effect.

III. Whenever an invention resides in the modification of a known article in order to improve its known capability, the modifying feature should not only characterise the invention in the claim, i.e. distinguish it from the prior art, but must contribute causally to the improvement of the capability thereby achieved.