Appeal No. 97-1243
Application 08/443,301
conduit and the delivery conduit. During diagnosis of the
tank system, the pump space of Stocker is connected to a
vacuum source (“Saugrohr - unterdruck” or “suction pipe
negative pressure”) when the electromagnetic valve is
energized and to ambient air via the supply conduit and a U-
shaped bypass conduit (not labeled) when the electromagnetic
valve is not energized, thereby causing the pump diaphragm to
execute a pumping motion.3
Concerning the operation of Stocker’s shut-off valve, we
find that when diagnosis is not being made, the shut-off valve
is in the illustrated lower position to allow for direct
communication between the supply conduit and the delivery
conduit. See PTO translation, page 9, lines 8-10 (“The
diagnostic pump is connected to the ventilation line of the
activated charcoal filter and, when at rest, opens this line.”
(emphasis added)). We further find that when diagnosis is
being made, Stocker’s shut-off valve is in a raised position
above the position shown in Figure 7 to prevent direct
communication between the supply conduit and the delivery
3See page 2, lines 2-24, of appellant’s specification and
the paragraph spanning pages 9 and 10 of the PTO translation.
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Last modified: November 3, 2007