Appeal No. 98-0599 Application 08/434,029 critical finding. Given that ribs are known as a means to minimize the entry of dust and contaminants into the central aperture, we agree with the examiner that it would have been obvious to one with ordinary skill in the art to add a 16Page: Previous 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 NextLast modified: November 3, 2007