Research Plastics v. Federal Packaging Corp.

The Research patent claims a ribbed caulking tube that permits air to flow out of the tube allowing a tight seal between the plunger and the adhesive material. The C.A.F.C. construed the term "rear end" to mean the rear edge of the tube, and not only the rearmost point of the tube. The C.A.F.C. relied on intrinsic evidence and prosecution history to construe the claim.
See also,

• MP3: Research Plastics v. Federal Packaging Corp. (Fed. Cir. 2005) (citations omitted)
• PDF: Research Plastics v. Federal Packaging Corp. (Fed. Cir. 2005) (full text)
• Patently-O: CAFC takes a new look at 'rear end' definition