Appeal No. 2002-1444 Page 4
Application No. 09/004,564
Answer, page 3), and takes the position that it would have been obvious to one of
ordinary skill in the art to replace the steel liner portion 24 of Peterson with the plastic
liner of Heinecke in order to make the layer 24 of Peterson “less susceptible to abrasion
and corrosion” (Answer, pages 3 and 5), and also because it would be “simpler”
(Answer, page 3).
Peterson discloses a gate valve having a valve body including a plurality of walls
defining a chamber. Two of these walls are disposed opposite one another and each
includes an aperture that can be closed by a valve gate reciprocally operating between
the walls. Peterson provides a seal which engages opposite sides of the valve gate to
prevent foreign matter from entering the valve body. The seal comprises a liner panel
(guide plate) 24, which is normally of steel (column 3, line 5), backed by a resilient
compressible sheet 22, which urges it into contact with the valve gate. There is no
teaching that element 24 is flexible. Thus, with regard to the language of claims 20 and
21, Peterson fails to disclose a liner panel that is “a non-metallic laminate formed by a
flexible layer of plastic material” (emphasis added), wherein the elastomeric material
urges the flexible layer of plastic material into sealing engagement with the gate.
In the gate valve structure disclosed by Heinecke the valve body is sealed
around the valve by a pair of liner panels 32 which, although not stated in the
specification, apparently are made of plastic, inasmuch as the cross-hatching used in
Figure 2 so indicates. There is no teaching in Heinecke that the plastic liner panels are
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