Print PDF

Court Remands Summary Judgment for Findings on Doctrine of Equivalents

April 02, 2002

Decision icon Decision

Last Month at the Federal Circuit - May 2002

Judges: Rader (author), Clevenger, and Bryson

In Leggett & Platt, Inc. v. Hickory Springs Manufacturing Co., No. 01-1255 (Fed. Cir. Apr. 2, 2002), the Federal Circuit reversed a district court’s SJ that Hickory Springs Manufacturing Company (“Hickory”) did not infringe claims 3 and 4 of Leggett & Platt, Inc.’s (“L & P”) U.S. Patent No. 5,052,064 (“the ‘064 patent”) and that Hickory did not misappropriate L & P’s trade secrets, given genuine issues of material fact concerning infringement under the DOE and trade-secret violations.

The ‘064 patent claims a stackable bedding foundation, often known as a box-springs assembly. In particular, the patent claims box springs that are “nestably stackable” for transportation so that no compression is necessary. Hickory’s accused product is known as the PowerStack.

The district court had construed the term “support wire” to mean a wire having only two ends, regardless of the number of welds in between. Hickory then moved for SJ of noninfringement, while L & P moved for SJ of misappropriation of trade secrets. The district court granted the former and denied the latter.

On appeal, L & P argued that the term “support wire” includes an assembly of separate wires welded together. The Federal Circuit observed that the specification distinguishes support wires from other types of wires, including border wires and connector wires. The figures show the support wires stretching from one border wire to the other. Accordingly, the Federal Circuit affirmed that the district court had correctly construed the term “support wires” to mean a continuous strand of wire with only two ends.

Concerning literal infringement, the Federal Circuit ruled that Hickory’s PowerStack device does not have support wires that fit the proper claim construction. Rather, the PowerStack product features support cups, which are wire baskets welded to longitudinal, end-to-end wires. The Court remanded the infringement issue, however, because the district court must determine whether the PowerStack product is equivalent to the support wires in the ‘064 patent, given several factual issues concerning the substantial differences between the PowerStack and the claim.

Concerning the trade-secret misappropriation issue, the district court had found genuine issues of material fact regarding misappropriation, but granted SJ in favor of Hickory because L & P had not shown sufficient evidence that Hickory had used L & P’s trade secret, as required by Illinois law. The Federal Circuit found genuine issues of material fact on the use element as well as misappropriation and, noting that the final decision may ultimately turn on the credibility of witnesses, determined that SJ was not appropriate.