Broad Claim Scope Survives Despite Single Embodiment Disclosure
Holding that a patentee is entitled to claim scope covering an entire class of devices based on the patent disclosure describing one device of the class, the U.S. Court of Appeals for the Federal Circuit reversed the grant of summary judgment of non-infringement based on a district court’s narrow claim construction, but remanded for further consideration of claim enablement and validity. The Saunders Group, Inc. v. Comfortrac, Inc., Case No. 06-1576 (Fed. Cir., June 27, 2007) (Bryson, J.).
Plaintiff Saunders manufactures cervical traction devices and competes with defendants in the marketplace. Saunders owns a patent directed to a portable cervical traction device and alleged that the defendants were infringing it. The district court granted a summary judgment of non-infringement, construing the claims to be requiring inclusion of at least one pressure-activated seal. The district court arrived at this narrow construction because the patent specification disclosed a single embodiment using the seal and because all of the claims in the parent application explicitly recited this limitation. Saunders appealed.
The Federal Circuit reversed, holding that based on the intrinsic claim construction evidence (the claim language, the specification and the prosecution history) the district court’s construction was impermissibly narrow. With regard to the doctrine of claim differentiation, which gives rise to a presumption that a limitation added in a dependent claim is not present in the independent claim, the Court held that the district court’s inclusion of at least one pressure activated seal as a limitation in the independent claims of the patent was incorrect, because the limitation was omitted from some independent claims while included in other independent and dependent claims. Next, looking at the patent specification, the Court concluded that the specification did not indicate that a pressure-activated seal was the only way to practice the invention. Thus, the Court concluded the invention, as disclosed, was not limited to the single embodiment described.
Next the Court looked to the prosecution history and concluded that there was nothing in the prosecution history to require that the claim term “pneumatic cylinder” be limited to pressure-activated seals, nor was the ordinary meaning of the term so narrow. Furthermore, the Court noted that when the continuation application that matured into the patent was filed, the limitation direct to pressure activated seal was omitted from some of the new claims. The Court found this to be a strong indication that the claims lacking the limitation were not intended to be so limited. Finally, the Court noted that in a Petition to Make Special Saunders had identified the accused device as infringing even though it lacked a pressure-activated seal.
After construing the claims broadly, the Court noted that in the event the specification is found to be too narrow to support the broad claims validity may be an issue on remand. However, the Court instructed that the possible invalidity should not be used by the district court to construe the claims narrowly.
Practice Note: This case is a reminder that when possible, prosecutors should include in their patent specifications sufficient disclosure to support multiple embodiments. Securing patent protection of a broad claim while disclosing only a single embodiment is typically an uphill battle especially where the involved field of technology is relatively new and unpredictable.