Appeal No. 2004-0109
Application 09/324,549
the claimed and reference weight percent ranges overlap with respect to Cu in the first and third
groups of the reference alloys, and with respect to Li in all four groups of reference alloys. With
respect to Li, the overlap is at the lower end of the weight percent ranges, that is, “0.1” in
appealed claim 19, and “0.2” in each of the four alloy groups of Rioja ‘792. Furthermore, Rioja
‘792 discloses that the aluminum lithium alloys disclosed therein are capable of attaining yield
strength and fracture toughness within ranges which overlap with the ranges for these properties
in appealed claim 19.
We find that Rioja ‘859 discloses lithium-containing aluminum base alloys which
can contain 0.2 to 5.0 wt.% Li, 0 to 5.0 wt.% Mg, up to 5.0 wt.% Cu, 0 to 2 wt % Ag,
0 to 1.0 wt.% Zr, 0 to 1.0 wt.% Mn, 0 to 9.0 wt.% Zn, 0.5 wt.% max. Fe, 0.5 wt.%
max Si, the balance aluminum and incidental impurities. [Col. 2, lines 50-55; Rioja
‘859 claims 13, 36, 43 and 49.]
Rioja ‘859 also discloses lithium-containing aluminum base alloys which can
contain 0.5 to 4.0 wt.% Li, 0.1 to 6.0 wt.% Mg, at least 0.6 wt.% Cu, 0.05 to 12 wt.%
Zn, 0 to 0.8 wt.% Mn, 0 to 0.15 wt.% max Zr, 0.05 to 1 wt % Ag, 0.5 wt.% max. Fe,
0.5 wt.% max Si, the balance aluminum and incidental impurities. [Col. 2, lines 62-66;
Rioja ‘859 claims 21, 37, 44 and 50.]
We further find that Rioja ‘859 would have taught one of ordinary skill in this art the
disclosed that processing the aluminum-lithium alloys by processes including the aging treatment
disclosed therein, enhances the yield strength and fracture toughness of the alloys (cols. 1-4).
Indeed, it is disclosed that
the presence of lithium in combination with other controlled amounts of alloying
elements permits the fabrication of aluminum alloy products which can be worked to
provide unique combinations of strength and facture toughness while maintaining
meaningful reductions in density. It will be appreciated that less than 0.5 wt. % Li does
not provide for significant reductions in the density of the alloy . . . . [Col. 3, lines 12-
26.]
We determine that one of ordinary skill in this art would have inferred from this quoted
passage in light of the disclosure of the reference as a whole that at least some reduction in
density is achieved at less than 0.5 wt.% Li even if not “significant,” and that toughness and
strength is provided by lithium in combination of with other elements of the alloy. We further
find that that Rioja ‘859 discloses in Table 1 and in FIG. 3 thereof that the disclosed processes
can provide a number of different yield strength (L) and fracture toughness properties for the
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