Appeal No. 1999-1818 Page 5
Application No. 08/586,806
Enda discloses making the push rod of an aluminum alloy, rather than copper, to match
its coefficient of thermal expansion with that of an aluminum alloy cylinder head (1) of an
engine to thereby minimize the increase in valve head gap due to thermal expansion of the
cylinder head (translation, pages 3 and 9). This, in turn, stabilizes the rigidity of the oil
pressure tappet (translation, page 4). The spherical end portions (14a) may be made of steel
(translation, page 10).
Sugiyama discloses a push rod 11 for transmitting force to a pressure plate 6 in a
friction clutch.
In rejecting claim 1 as unpatentable over Macura in view of Enda, the examiner finds
that Macura discloses the claimed subject matter with the exception of the rod body being
formed from an aluminum alloy but takes the position that it would have been obvious to one of
ordinary skill in the art at the time the invention was made, in view of the teachings of Enda, to
make the push rod and engine body of Macura of aluminum alloy for the purpose of
suppressing an increase in capacity in the pressure oil chamber (answer, page 4). Likewise, in
rejecting claim 1 as unpatentable over Macura in view of Sugiyama, the examiner asserts that it
would have been obvious to one of ordinary skill in the art to use the push rod disclosed by
Macura in the friction clutch of Sugiyama for the purpose of reducing weight and that to use
aluminum alloy for the rod body would have been an obvious matter of design choice (answer,
pages 5 and 6).
Page: Previous 1 2 3 4 5 6 7 8 9 10 11 Next
Last modified: November 3, 2007