Steve Stumbo v. Ameristep Corporation
http://www.cafc.uscourts.gov/opinions/07-1186.pdf (Fed Cir. 2007)
• Procedural History:
Stumbo brought suit against Ameristep and Eastman Outdoors (collectively “defendantsâ€), claiming infringement of his patent #5,628,338 (the ‘338 patent). After construing the important language in the ‘338 patent, the district court judge sitting in the Eastern District of Colorado granted defendant’s motion for summary judgment, finding no literal infringement or infringement under the doctrine of equivalents.
• Stumbo’s patent and Defendants’ infringing products:
Stumbo’s patent at issue, the ‘338 patent, is a a portable and collapsible hunting shelter or blind that allows quick and easy set-up by hunters, photographers, and other wildlife enthusiasts. The shelter is hub-style with four walls and a top made of fabric, with the structure being supported by five support members. The portion of the ‘338 patent at issue here is the “closable vertical opening at a side edge or vertical corner†at which point one can enter the shelter. See the image attached for a drawing of the '338 patent.
The defendants’ products are similar shelters, however, the entrance is a triangular shaped “loose door flap†placed along a zipper line diagonally from one corner to the center, then back again diagonally to the other corner on the same side as the first.
• Stumbo’s infringement claim and Ameristep’s defenses:
Stumbo claims that the “closable vertical opening at a side edge or vertical corner†language is infringed, if not literally, but under the doctrine of equivalents, by the defendants’ entrance to their respective shelters.
Ameristep responded that the triangular entrance did not literally infringe, and that the doctrine of equivalents could not save plaintiff’s infringement claim.
• Holding:
After reviewing the district court’s grant of summary judgment de novo, the Federal Circuit affirmed the grant of summary judgment.
The court began by constructing the claim at issue in the ‘338 patent – the “closeable vertical opening at a side edge or vertical corner.†The court agreed with the district court that this term is properly construed as a a closable vertical opening†is properly construed as “a slit-like opening that runs straight up and down or perpendicular to the plane of the horizon.†The court found that there was no special meaning in the hunting blind industry to this term. Stumbo wanted a construction that equated vertical to any shape with a vertical height greater than the horizontal width. However, the court found that in light of the specification and no special meaning, this construction was not correct. Further, the court found that no limitation was read into the claim from the specification. After this construction, there was no debate that the defendants’ products did not literally infringe.
The court then moved to the question of whether the offending product infringed under a doctrine of equivalents analysis. The critical question is asked was whether the difference between the claimed invention and the accused product was insubstantial, performing substantially the same function in substantially the same way with substantially the same result as each claim limitation of the patented product. The defendants’ engineer noted that the ‘338 patent required flex in the supporting members, while the defendants’ design required no such flex. Further, the engineer claimed that the resulting opening was different and safer for hunters and photographers.
The court found that the engineer’s testimony shows that a person of ordinary skill in the art would conclude that the offending product achieves a substantially different result in a substantially different way. Thus, there could be no infringement under this equivalents analysis.
• Importance:
This case shows the importance of claim drafting and construction. It also shows how one can litigate one’s self into a corner. Although the appellate court did not reach the issue because of a finding of no infringement, literal or equivalent, the plaintiff could have been on course to invalidate his patent. It was briefly mentioned that if the plaintiff’s preferred construction was accepted – that is the vertical opening covering any shape with a vertical height greater than a horizontal width – the plaintiff may have faced a problem with the prior art anticipating the design.
• Critical Analysis:
This seems to be a straightforward infringement analysis, made easier by either clever design or legal advice on the part of the defendant. Although I would question the patentability of either of these inventions as an initial matter, once the plaintiff’s patent is accepted and the claim construction easily completed, it is clear there is no literal infringement. The claim construction by both courts is really the only workable construction; the plaintiff’s own construction may have invalidated the claim, if accepted. On the doctrine of equivalents analysis, I only disagree with the court on one point: the substantially same result is achieved – ingress or egress from the shelter. However, I agree that the way this result is achieved is substantially different. This is primarily because the rigidity of the structure is not compromised in the defendants’ design, whereas it is in the plaintiff’s design. Furthermore, if you consider how a human would actually enter the structure after visualizing the openings, it seems clear that entry is achieved in a substantially different way.
http://www.cafc.uscourts.gov/opinions/07-1186.pdf (Fed Cir. 2007)
• Procedural History:
Stumbo brought suit against Ameristep and Eastman Outdoors (collectively “defendantsâ€), claiming infringement of his patent #5,628,338 (the ‘338 patent). After construing the important language in the ‘338 patent, the district court judge sitting in the Eastern District of Colorado granted defendant’s motion for summary judgment, finding no literal infringement or infringement under the doctrine of equivalents.
• Stumbo’s patent and Defendants’ infringing products:
Stumbo’s patent at issue, the ‘338 patent, is a a portable and collapsible hunting shelter or blind that allows quick and easy set-up by hunters, photographers, and other wildlife enthusiasts. The shelter is hub-style with four walls and a top made of fabric, with the structure being supported by five support members. The portion of the ‘338 patent at issue here is the “closable vertical opening at a side edge or vertical corner†at which point one can enter the shelter. See the image attached for a drawing of the '338 patent.
The defendants’ products are similar shelters, however, the entrance is a triangular shaped “loose door flap†placed along a zipper line diagonally from one corner to the center, then back again diagonally to the other corner on the same side as the first.
• Stumbo’s infringement claim and Ameristep’s defenses:
Stumbo claims that the “closable vertical opening at a side edge or vertical corner†language is infringed, if not literally, but under the doctrine of equivalents, by the defendants’ entrance to their respective shelters.
Ameristep responded that the triangular entrance did not literally infringe, and that the doctrine of equivalents could not save plaintiff’s infringement claim.
• Holding:
After reviewing the district court’s grant of summary judgment de novo, the Federal Circuit affirmed the grant of summary judgment.
The court began by constructing the claim at issue in the ‘338 patent – the “closeable vertical opening at a side edge or vertical corner.†The court agreed with the district court that this term is properly construed as a a closable vertical opening†is properly construed as “a slit-like opening that runs straight up and down or perpendicular to the plane of the horizon.†The court found that there was no special meaning in the hunting blind industry to this term. Stumbo wanted a construction that equated vertical to any shape with a vertical height greater than the horizontal width. However, the court found that in light of the specification and no special meaning, this construction was not correct. Further, the court found that no limitation was read into the claim from the specification. After this construction, there was no debate that the defendants’ products did not literally infringe.
The court then moved to the question of whether the offending product infringed under a doctrine of equivalents analysis. The critical question is asked was whether the difference between the claimed invention and the accused product was insubstantial, performing substantially the same function in substantially the same way with substantially the same result as each claim limitation of the patented product. The defendants’ engineer noted that the ‘338 patent required flex in the supporting members, while the defendants’ design required no such flex. Further, the engineer claimed that the resulting opening was different and safer for hunters and photographers.
The court found that the engineer’s testimony shows that a person of ordinary skill in the art would conclude that the offending product achieves a substantially different result in a substantially different way. Thus, there could be no infringement under this equivalents analysis.
• Importance:
This case shows the importance of claim drafting and construction. It also shows how one can litigate one’s self into a corner. Although the appellate court did not reach the issue because of a finding of no infringement, literal or equivalent, the plaintiff could have been on course to invalidate his patent. It was briefly mentioned that if the plaintiff’s preferred construction was accepted – that is the vertical opening covering any shape with a vertical height greater than a horizontal width – the plaintiff may have faced a problem with the prior art anticipating the design.
• Critical Analysis:
This seems to be a straightforward infringement analysis, made easier by either clever design or legal advice on the part of the defendant. Although I would question the patentability of either of these inventions as an initial matter, once the plaintiff’s patent is accepted and the claim construction easily completed, it is clear there is no literal infringement. The claim construction by both courts is really the only workable construction; the plaintiff’s own construction may have invalidated the claim, if accepted. On the doctrine of equivalents analysis, I only disagree with the court on one point: the substantially same result is achieved – ingress or egress from the shelter. However, I agree that the way this result is achieved is substantially different. This is primarily because the rigidity of the structure is not compromised in the defendants’ design, whereas it is in the plaintiff’s design. Furthermore, if you consider how a human would actually enter the structure after visualizing the openings, it seems clear that entry is achieved in a substantially different way.