Ex parte Szymbor
Appeal 2009011926, Appl. NO. 10/104,337, Tech. Center 3600
Decided August 24, 2010
The subject matter of the patent application was a seal for a gas turbine engine, used to prevent gas from escaping through a gap between stationary and rotating parts. This type of seal, known as a "brush seal," includes packs of wire bristles sandwiched between plates.
One of the claims on appeal read:
12. A brush seal, comprising: a bristle arrangement, including:
a plurality of bristles, each of said bristles having a first end and an opposed second end; and
plates receiving said bristles therebetween, each of said plates having a first end and a second end;
wherein said first ends of said bristles extend past said first ends of said plates and said second end of said bristles resides between said first and second ends of said plates.
One of the Applicant's arguments was about the "first end" and "second opposed end" limitations. As is common, the underlying issue was really claim construction.
The reference used by the Examiner is shown below, where bristles 2 are bent in half around, and retained by, ring 8.
Specifically, the Examiner read the claimed "first end" on the portion of the bristle 2 which contacted the sealing surface 20. The Examiner read the "second end" on the portion of the bristle which is retained by the ring 8. The Examiner explained this interpretation as follows:
[E]nd is defined by a boundary marking extremities of something, the boundary of the bristles in Reisenger et al. is the second end marking the extremity of the bristle arrangement.Having interpreted "ends" to be top and bottom portions of the bristle, the Examiner then found that the top portion ("second end") was "opposed" to the bottom portion ("first end").
The Applicant argued that the ends of the bristle were those portions that contact the sealing surface 20, and that these portions were aligned rather than opposed. The Applicant cited to a portion of the reference which read: "The ends of the wire bundle 2 extend in parallel and radially toward the inside to thus form a sealing element which slides on a sealing surface 20 ..."
The Board used dictionary definitions of "opposed" and "end" to interpreted "opposed second end" as "the extreme or last part of the bristle in opposition or contrary to its first end." The Board then found that the Examiner's interpretation of "second end" as the midpoint of the bristle 2 (where the bristle 2 wraps around the ring 8) was "unreasonable" and "contorts the ordinary and customary meaning as understood by a person having ordinary skill in the art."
My two cents: This seems like another case where the Examiner designated arbitrary portions of a structure to meet the claim limitation. The Examiner's definition of "end" closely tracked the Board's definition -- extremity. But a wire has two recognizable ends, and bending the wire in half doesn't make the midpoint into an end.
It occurred to me that the two real ends of the U-shaped bristle actually are opposed to each other. So why did the Examiner use this tortured reading of end as midpoint? My guess is using the natural interpretation of "ends" does meet the "opposed" limitation, but in doing so one or more of the other claim limitations isn't met.
Related Posts: Other posts discussing arbitrary delineation of structures by the Examiner are here and here.