Appeal No. 2001-0735 Page 8
Application No. 09/135,390
Since the fluid is introduce into the closed casing
through the hollow main shaft or the pressurized fluid is
discharged through the hollow main shaft, the distance
between the fluid introducing portion/pressurized fluid
discharging portion and the pressure chamber is longer as
compared with the conventional electromagnetic
reciprocating pump, which produces a pulsation absorption
effect, and the pulsation sound of the fluid generated in
compression/attraction of the fluid less often leaks out,
which can contribute to the noise eliminating effect.
The real issue presented in this appeal is whether or not
it would have been obvious at the time the invention was made
to a person of ordinary skill in the art to have reversed the
direction of the fluid flow in the vacuum unit of the Admitted
Prior Art in view of the teachings of Osada. On this issue,
we find ourselves in agreement with the position of the
appellant as set forth in the brief. In our view, Osada, at
best, would have made it obvious at the time the invention was
made to a person of ordinary skill in the art to reverse the
direction of the fluid flow in a pump only if this would
result in the pulsation of the pressurized fluid being
smoothed by the resistance of a fluid passage similar to the
fluid passage 5A in Osada's hollow main shaft 5. Since the
plenum base 16 in the vacuum unit of the Admitted Prior Art
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