Appeal No. 97-2228
Application 08/509,259
other types of hollow airfoils which are subject to vibration
(see column 3, lines 19 through 26). As summarized by Rimkunas,
[d]amping for the airfoils of stator vanes is provided
by a spring damper formed from an elongated spring
element bent into a “U” or “V” shape in cross section
and oriented in the hollow of the airfoil so that the
legs of the “U” or “V” frictionally engage the inner
surfaces of the opposing pressure side and suction side
walls of the airfoil to dissipate the vibratory energy.
The elongated spring element is inserted through a hole
formed on one end of the airfoil to extend just short
of one of the ends of the airfoil to form a
cantilevered mounted spring [Abstract].
Figures 2, 4 and 5 show that the spring damper 39 or 70 is
received within an internal airfoil cavity via a hole or aperture
60 or 82 formed or cut in the base of the airfoil (see column 3,
line 59 through column 4, line 59).
Claims 1 and 12, the two independent claims on appeal,
recite a rotor blade comprising, inter alia, a platform extending
laterally outward from the blade between its root and airfoil,
and an aperture extending between the root side of the platform
and a cavity within the airfoil for receiving a damper. The 3
appellants’ position that Rimkunas does not disclose such
structure (see pages 3 through 5 in the brief) is well taken.
3The term “said surface within said cavity” in the last
clause of claim 12 lacks a proper antecedent basis, an
informality which is deserving of correction in the event of
further prosecution before the examiner.
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