Appeal No. 2003-0651 Page 4
Application No. 09/348,761
Druyan discloses a transverse helical roller for use in the tube-rolling industry
comprising an entry cone whose generatrix is formed from smoothly joined concave 1
and convex 2 arcs, ridge 3, expander or sizing section 4 and exit cone 5. The concave
and convex arcs may have a common chord AB passing through the starting point of
the generatrix of the entry cone and the ridge. According to Druyan, this
concave/convex curvilinear entry cone provides a smooth change in the speed of the
billet when the deformation area is being filled, thereby reducing the dynamic loading on
the rollers at the moment the billet is grasped by the rollers and increasing the reliability
with which the deformation area is filled by metal and increasing the durability of the
rollers and quality of the product. Druyan never uses the term “parabolic” to describe
the shape of the concave and convex arcs but does disclose (translation, page 3) that
the concave and convex arcs may, for example, have a constant radius of curvature.3
The examiner’s position appears to be that it would have been obvious to one of
ordinary skill in the art at the time of appellants’ invention to provide a surface of
revolution as taught by Druyan on the rolling mill plug of Delans to reduce dynamic
loading on the rolls and thereby improve service life and product quality (see answer,
page 3). Appellant argues that Druyan does not disclose or suggest parabolic surfaces
(brief, page 7) and urges that, even if Delans and Druyan were combined, appellants’
invention as recited in claim 13 would not result.
3 An arc having a constant radius of curvature would not be parabolic.
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