Appeal No. 97-2904
Application 08/565,457
operates valve 116 to connect chamber 82 to pump 90 to thereby
establish a high vacuum level in chamber 82 for lifting the
sheet from a platen 12 and for securely retaining it against
belts 70 and 72. In the second mode of operation, which occurs
as the sheet approaches the registration member 34, controller
136 operates valve 136 in the reverse fashion to disconnect
chamber 82 from pump 90 and to restore atmospheric pressure to
chamber 82. The lower vacuum level in chamber 84 is sufficient
to retain the sheet against belts 70 and 72 to allow the sheet
to strike registration member 34 without damaging the sheet.
Appellant argues that Dragstedt is deficient for the
following reasons:
This patent does not teach that the sheet
slips on the belt when it engages the
registration member. This patent also does
not teach means for sensing the sheet
advancing on the transport and a controller
responsive to the sensing means for
switching the transport between modes of
operation. Furthermore, there is no
teaching contained in this patent that the
frictional force between the sheet and the
transport is reduced to permit relative
movement between the sheet and the
transport. At most, this reference teaches
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