Appeal No. 1997-3785 Application No. 08/527,591 the case in the appellants’ invention. The remaining two applied references do not alter the principles of operation of the Cmejrek system. It therefore is clear to us that one of ordinary skill in the art would not have been taught by Cmejrek to insure that the temperature of the gases exhausting from a boiler or the like was adequate to accomplish the desired level of purging by “raising the temperature” of the gases at all, much less doing so to a “part” of the gases “prior to entry” of the gases into the component that is to be purged, as is required by claim 1. The mere fact that the prior art could be modified does not make such a modification obvious absent suggestion of the desirability of doing so. See, for example, In re Gordon, 733 F.2d 900, 902, 221 USPQ 1125, 1127 (Fed. Cir. 1984). In the present case, we fail to perceive any teaching, suggestion or incentive in the applied references which would have led one of ordinary skill in the art to modify the Greco system in the manner proposed by the examiner. It appears to us that the only suggestion for doing so is found in the hindsight accorded one who first viewed the appellants’ disclosure. 10Page: Previous 1 2 3 4 5 6 7 8 9 10 11 12 13 NextLast modified: November 3, 2007