Appeal No. 98-2118
Application No. 08/459,986
of chord to pitch is constant from half the vane height to the
inner radius, it follows that the chord must "generally"
increase from a first value near the root to a second larger 4
value at a part span location (i.e., the midpoint of the vane
height) and "generally" constant from that location to the tip
as broadly set forth in independent claims 1 and 9. This
interpretation is reinforced by the fact th2at Elvekjaer also
expressly states, as we have noted above, that the guide vanes
are tapered radially inwards. From our perspective, the
above-noted teachings of Elvekjaer establish a prima facie
case of anticipation.
The appellants on page 6 of the brief contend that:
Pitch T [of Elvekjaer] is the circumferential offset
between common points (e.g. the leading edge) on
neighboring vanes (see Fig. 2 of the reference) and
can only be interpreted as a quantity which
decreases with decreasing radius (as opposed to
being a constant offset taken at an arbitrary
radius).
4In Column 2, lines 59-62, Elvekjaer states that:
the root of the vane guide is understood as being
positioned at the outer diameter of the vane, that
is, in the vane carrier 3, and the vane tips as
being positioned at the inner diameter, that is, at
the hub 2. [Emphasis added.]
8
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