Appeal No. 99-0158
Application 08/616,787
define a closed periphery circumscribing that
portion of the surface area of the blank TB which is
in lateral operative projection with the die surface
or shaping member 20. The shaping member 20
adjacent the plug members 23 and 24 is provided with
relief radii 26 to minimize initial stress
concentrations. The final shape of the part formed
by the apparatus of FIGURE 3 is shown by broken line
a [column 5, lines 27 through 55].
With additional regard to the process involved, Fields states
that
[f]ull performance of our discovered process
requires that the metal blank be heated or otherwise
conditioned to exhibit its effective strain rate
sensitivity as indicated above and placed in the
apparatus provided in operative projection with an
opposed die portion. Tensile deforming stress is
then induced in the blank by application of a load
through a fluid pressure interface. . . . Loading
is continued until the blank has deformed against
and into intimate contact with the shaping member or
die surface [column 6, lines 30 through 41].
As conceded by the examiner (see page 4 in the answer),
Fields does not meet the limitations in independent claims 1,
10 and 23 requiring the end caps to have a coefficient of
thermal expansion greater than that of the tube. As explained
in the appellant’s specification, and as set forth to some
extent in claims 1 and 10, this difference in the coefficients
of thermal expansion produces a gas-tight seal between the end
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Last modified: November 3, 2007