When drafting patent claims, one important goal is to describe the invention and how to make and use the invention.  35 U.S.C. Section 112.  Another goal is to write claims that read on all disclosed embodiments.  Thus, another interesting point about Rolls-Royce, PLC v. United Technologies Corp., 2010 U.S. App. LEXIS 9201 (Fed. Cir. May 5, 2010), discussed below, is that the Court construed an independent claim to not read on an embodiment disclosed in a patent application drawing.  Rolls-Royce involved an appeal under 35 U.S.C. Section 146 from a ruling on an interference.  The details of the interference are not important to this discussion.  However, the Federal Circuit was required to determine whether independent claim 23 in United Technologies Corporation's '931 application rendered obvious independent claim 8 of Rolls-Royce PLC's '077 patent.  In discussing this issue, the Federal Circuit ruled -- contrary to UTC's arguments -- that claim 23 did not read on an embodiment disclosed in Figure 5 of the '931 application.  The opinion did not specifically discuss whether another independent claim of the '931 application read on Figure 5.   

Both the '931 application and the '077 patent related to swept fan blades used in turbofan jet engines.  These blades rotate about an axis of rotation.  The opinion explains that the prior art taught that to "reduce shockwaves, blades sweep either rearward or forward."  Id. *2.  The opinion further explains that, "A blade bent toward the relative velocity vector is swept forward; a blade bent away from the velocity vector is swept rearward.  The relative velocity vector is the magnitude and direction of the air flow that hits the leading edge of a fan blade.  The relative velocity vector is a combination of axial and circumferential air flow."  Id. *2-3.

The claimed shape of the blades was the primary claim construction issue.  In particular, claim 23 of the '931 application recited in part, "A fan stage of a ducted fan gas turbine engine that is rotatable about an axis of rotation and defines a downstream direction along the axis of rotation."  Id. *5.  Claim 23 further recited "a leading edge [of a blade] that defines a variable sweep angle in a direction perpendicular to the axis of rotation ***."  Claim 23 further recited an outer portion of the blade with the leading edge "translated forward ***."  Id. *9.  A key issue was the meaning of "translated forward." 

The District had interpreted "translated forward" to mean "moving axially forward ***."  Id. *12.  That is, the outer portion of the blade moved forward along the axis of rotation.  UTC argued for a broader construction that included movement "forward toward the relative velocity vector."  Id. *15.  The Federal Circuit described UTC as contending that, "movement in any direction -- axial or circumferential -- is movement toward the relative velocity vector."  That is, under the UTC's proposed claim construction, "either purely circumferential or purely axial movements are encompassed by the term 'translated forward.'"  Id. *15-16. 

The Federal Circuit noted that Figure 5 of the '931 application showed movement of the outer region of the blade in the circumferential direction.  But the Court noted that the specification of the '931 application did not use the term "translated forward" to describe the embodiment of Figure 5.  "Instead, the specification describes the movement in Figure 5 as 'displaced circumferentially.'"  Id. *17.  The Court then stated that, "This court's construction of 'translated forward' ('moved forward toward the axial direction') excludes the embodiment of Figure 5."  The Court stated, "Although reluctant to exclude an embodiment, this court must not allow the disclosed embodiment to 'outweigh the language of the claim, especially when the court's construction is supported by the intrinsic evidence.'" Id. *17, quoting TIP Sys., LLC v. Phillips & Brooks/Gladwin, Inc., 529 F.3d 1364, 1373 (Fed. Cir. 2008).

In this case, it appears claim 23 did not read on Figure 5 primarily because the specification described Figure 5 as showing a blade that is "displaced circumferentially" instead of describing the blade as being "translated forward" toward the relative velocity vector.  Because of this, the Court refused to allow the claimed direction "forward" to encompass two directions at right angles to each other.  Id. *17.  That is, both the axial direction and the circumferential direction.  Thus, this is an example of  a disclosed embodiment that was not claimed by an independent claim.

In general, as a practice suggestion, it appears that practitioners can prevent failures to claim disclosed embodiments by some combination of expressly defining important terms, using the same terminology consistently throughout the specification and the claims, and by checking that the claims and the specification are consistent with each other.  Some practitioners prefer not to expressly define terms.  A rigid or poor definition can be worse than no definition at all.  This concern is a vaild one, but if a term used in both the specification and the claims does not have a precise meaning in the art, then a broad definition is probably best.  Opinions differ on this issue.