Appeal No. 2001-0774
Application 09/087,521
in a recycle hopper not shown and is recycled to cyclone assembly 55 through duct 54,” and that
the recycled powder is conveyed from the recycle hopper through duct 54 to the inlet of cyclone
55 by communicating through conduit 63 with vacuum tank 51 and suction blower 52, wherein
“[s]uction blower 51 [sic, 52] discharges into duct 53 which in turn discharges into recycle
hopper (not shown) where the powder is recovered for recycle” (col. 4, line 67, to col. 5, line 2,
col. 5, lines 23-33, and Heckman FIG. 2). Thus, the only vacuum system taught by Heckman
pulls the recycle powder from the recycle hopper and into the cyclone. Cf. Gibson, col. 4, lines
42-46, wherein the powder is pulled through the pipe and then pushed towards a chute.
We find that the powder preconditioning system of Heckman uses the same vacuum
pump to pull new powder into a cyclone and then into a drying fluidized bed in chamber 10 from
which the preconditioned powder is “withdrawn . . . by aspiration (i.e., venturi action)” through
powder outlet duct 45, as governed by “flow control valve 48 which regulates the withdrawal
rates of dry powder,” to tube 49 which “connects to the inlet 47 of cyclone assembly 55” along
with duct 54 from the recycle hopper (col. 4, lines 32-51, coil. 5, lines 23-28, and Heckman FIG.
2). We find that while the preconditioned new powder was withdrawn from chamber 10 by
aspiration through duct 45, there is no disclosure of any additional air being applied to duct 45
for such purpose in either col. 4 or FIG. 2 of Heckman. It is further clear from the reference that
vacuum tank 51 and suction blower 52 cause “the pressure differential for gas flow and
pneumatic transfer of the powder through the system as indicated by the arrows” (col. 5, lines 23-
28), one such “arrow” shown in tube 49 in the direction of duct 54 and inlet 47. Thus, one of
ordinary skill in this art would have reasonably inferred that the aspiration or venturi action is
caused by the shape of duct 45 and the suction applied vacuum tank 51 and suction blower 52
through tube 49.
Thus, we find no teaching in Heckman from which one of ordinary skill in this art would
have reasonably inferred that apparatus elements of the preconditioning system thereof would
serve as apparatus elements for the transport of powder from the “powder coating structure”
through a “vacuum pump” to a “powder accumulator” in either the electrostatic spray gun
application system of Heckman or the “conventional” electrostatic fluidized bed application
system acknowledged in English as the examiner contends (answer, pages 5 and 10). Even if it
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