thereby increases to a very considerable degree the amount of heat which is absorbed from each can in the process of vaporization of the moisture. Dissipation of heat by each of the three principles of heat loss by the cans and their contents is still further expedited by the tumbling * * *. [Emphasis ours.]
This evaporation is a function of the machine throughout the cooling process and the machine was designed to wet the cans from all sides, the water dripping from the cans being recirculated. We see nothing to suggest any need for an improved wetting of the cans. We find no teaching, axiomatic or otherwise, to suggest the greater efficiency which Adams has discovered.
Finally, the solicitor adds the argument that the superiority of appellant's heat transfer is inherent in the use of foam. Again we observe that, of course, it is. But the art does not suggest the use of foam in heat transfer of any kind and there is not the slightest suggestion that anyone knew of the existence of this inherent superiority until Adams disclosed it. After all, Bell's telephone was "inherently" capable of transmitting speech, DeForest's triode was "inherently" capable of amplification, and, to come down to date, so was the tiny transistor which is rapidly supplanting it. Two of our decisions are cited as supporting the erroneous notion that "subject matter cannot be patented on the basis of an inherent property." We think the proposition thus broadly stated and as applied here is so transparently erroneous as not to require discussion. 57
Identification of Relevant Relationships Between Invention Elements
The Wesslau and Adams decisions illustrate the nature of the TSM inquiry. In each decision the court identified salient relationships between the elements of the claimed invention. Then, it looked to the prior art to see if those relationships are hinted at or would otherwise be obvious to one skilled in the art, based only on the prior art. When one could not reasonably identify how the prior art would cause an inventor to naturally identify one or more of the relationships between the elements, then the invention in question was nonobvious. Which relationships are salient is a highly fact specific question, depending on the invention and the area in which the invention lives.
In some cases this relationship is identified as “unexpected results” of a particular combination, in other cases it can be the lack of “inherency” of the particular combination; many other expressions of these relationships also exist. Which relationships the court will focus on is determined by the precise contours of the invention and its subject area. Given the inexorable march of technology, it is impossible to identify any particular relationship as always relevant, thus the great variety of ways of operationalizing the TSM test. The one constant in these analyses is the search for a reasonable explanation why prior art elements would have been combined, based on the prior art record.
356 F.2d at 1001-1003.