Appeal No. 2004-0109
Application 09/324,549
col. 3, line 13, to col. 4, line 68), and, in this respect, discloses that “less than 0.5 wt.% Li does
not provide for significant reductions in the density of the alloy. It is not presently expected that
higher levels of lithium would improve the combination of toughness and strength of the alloy
product” (col. 3, lines 23-28). This person would have reasonably inferred from the quoted
passage that at least some reduction in density is achieved at less than 0.5 wt.% Li even if not
“significant,” and that a larger amount of Li does not necessarily improve toughness and strength.
Rioja ‘792 would have also disclosed that “if it is desired to increase toughness at a given
strength level, then Cu should be added” (col. 3, lines 36-38). We still further find that Rioja
‘792 would have disclosed the processing steps, including artificial aging, whereby the aluminum
lithium alloys can attain yield strengths as high 95 ksi, wherein “useful strengths are in the range
of 50 to 85 ksi and corresponding fracture toughnesses are in the range of 25 to 75 √in.” (e.g.,
col. 5, line 22, to col. 9, line 17, particularly col. 7, lines 55-66; Rioja ‘792 claim 19).
We find that one of ordinary skill in this art routinely following these teaching of Rioja
‘792 would have reasonably arrived at aluminum lithium alloys which are capable of attaining
the properties taught by the reference. In other words, one of ordinary skill in this art can select
the elements from among those disclosed, in any amount within the weight percent range taught
for each element, to form an aluminum lithium alloy that is capable of attaining yield strength
and fracture toughness within the ranges for these properties taught by Rioja ‘792. Indeed, Rioja
‘792 would have disclosed to this person the function of the elements, separately and combined,
such as the disclosure that “while lithium is the most important element for saving weight, the
other elements are important in order to provide the proper levels of strength, fracture toughness,
corrosion and stress corrosion cracking resistance” (col. 3, lines 29-49).
Upon comparing the claimed aluminum alloys encompassed by appealed claim 19 with
the aluminum-lithium alloys disclosed by Rioja ‘792, we find with respect to each of the four
groups of alloys in the reference, that the claimed weight percent ranges, including the weight
percent ranges disclosed for Zr, Fe and Mn which can be present, either fall within or encompass
the weight percent ranges in the reference, except for the amount of Cu and Li. In the latter case,
1992); In re Preda, 401 F.2d 825, 826, 159 USPQ 342, 344 (CCPA 1968), presuming skill on
the part of this person. In re Sovish, 769 F.2d 738, 743, 226 USPQ 771, 774 (Fed. Cir. 1985).
- 7 -
Page: Previous 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Next
Last modified: November 3, 2007