NOTE: This disposition is nonprecedential.

United States Court of Appeals 

for the Federal Circuit 

__________________________ 

LEARNING CURVE BRANDS, 

Plaintiff-Appellant, 

v. 

MUNCHKIN, INC., 

Defendant-Appellee. 

__________________________ 

2011-1036 

__________________________ 

Appeal from the United States District Court for the 

Western District of Wisconsin in case No. 09-CV-0416, 

Senior Judge Barbara B. Crabb. 

___________________________ 

Decided: March 30, 2012 

___________________________ 

R. TREVOR CARTER, Faegre Baker Daniels LLP, of Indianapolis, Indiana, argued for plaintiff-appellant. With 

him on the brief was DANIEL M. LECHLEITER. 

JOSEPHINE K. BENKERS, Quarles & Brady, LLP, of 

Madison, Wisconsin, for defendant-appellee. 

__________________________ 
LEARNING CURVE v. MUNCHKIN 2

Before BRYSON, MAYER, and MOORE, Circuit Judges. 

BRYSON, Circuit Judge. 

This case arises from the second round of patent litigation between two manufacturers of children’s drinking 

containers, commonly known as “sippy cups.” Learning 

Curve Brands alleged that Munchkin, Inc.’s newest sippy 

cup models infringe Learning Curve’s U.S. Patent No. 

7,185,784 (“the ’784 patent”). The district court ruled that 

the accused cups did not infringe the patent because they 

lacked one of the claimed limitations. We affirm. 

The ’784 patent is directed to disposable children’s 

drinking cups that have lids with drinking spouts designed to minimize spills and leakage. Claim 1 recites 

(emphasis added): 

1. A drinking container comprising 

a main body . . . having a rim about its opening, 

the rim having . . . inner and outer walls defining a recess therebetween, the outer wall 

of the rim having a lower, distal edge spaced 

apart from the inner wall to define a recess 

opening; and 

a removable lid secured to the main body . . . the 

lid defining a groove about its edge sized to 

receive and snap over the rim of the main 

body and form a seal; . . . 

the groove about the lid has an inner surface, and 

the rim of the main body has an outer surface, that each define semi-circular arcs of 

similar radii and have interlocking features 
3 LEARNING CURVE v. MUNCHKIN

on an inboard side, the interlocking features 

including 

a first lip projecting radially outward from the 

lid into the groove and 

a second lip projecting radially inward from 

the outer surface of the rim of the main 

body to produce a nominal radial interference between the first and second lips 

as the lid and main body are engaged. 

In 2007, Learning Curve and a co-plaintiff sued 

Munchkin in the United States District Court for the 

Western District of Wisconsin, alleging that Munchkin’s 

sippy cups infringed the ’784 patent and another patent 

not at issue here. See First Years, Inc. v. Munchkin, Inc., 

575 F. Supp. 2d 984 (W.D. Wis. 2008). The accused cups 

in that case had lids that snapped onto the body of the 

cup. After the court granted the plaintiffs’ motion for 

summary judgment of infringement in that case, the 

parties stipulated to a consent judgment, including a 

stipulation of the patent’s validity. 

Munchkin subsequently began making disposable 

sippy cups with screw-on, rather than snap-on, lids. 

Learning Curve sought to have Munchkin held in contempt for violating the consent judgment in the First 

Years case. When the district court denied that request, 

Learning Curve filed this action against Munchkin, once 

again alleging infringement of the ’784 patent. 

The district court held a claim construction hearing at 

which it construed several disputed terms of the patent. 

Notably, the district court construed the term “snap” not 

to require any audible feedback, contrary to the position 
LEARNING CURVE v. MUNCHKIN 4

urged by Munchkin. The court also concluded that a 

“snap” method of attaching the lid to the body of the cup 

was not incompatible with having a threaded interface; 

thus, the court ruled, the lid could screw onto the cup and 

still “snap [to] form a seal” as required by the claim 

terms. And, pertinent to this appeal, the court construed 

the term “semi-circular arcs of similar radii” to mean that 

“[t]he inner surface of the groove and the rim of the main 

body are curved at respective radii so that the inner 

surface and the rim remain in nearly continuous contact 

over the extent of the semi-circular arcs when the lid and 

body are assembled.” 

The parties then cross-moved for summary judgment. 

The court concluded that “undisputed evidence shows 

that the grooves about the lids and the rims of the accused products do not ‘define semi-circular arcs of similar 

radii.’” Based on that conclusion, the court held that the 

accused products did not infringe the ’784 patent either 

literally or under the doctrine of equivalents. With respect to literal infringement, the court relied on evidence 

presented by the plaintiff’s expert, who used a micro 

computed tomography (CT) scanner to scan the crosssections of the accused devices at 15 degree intervals. 

The scan showed that the arcs formed by the inner surface of the groove in the lid and the outer surface of the 

rim of the cup were in contact over only 79-80% of their 

respective surface areas. That amount of contact, the 

court concluded, did not qualify as “nearly continuous.” 

With respect to the doctrine of equivalents, the court 

concluded that the “accused product may perform substantially the same function to achieve substantially the 

same result, but it does not do so in substantially the 

same way.” According to the court, that was because the 

arcs in the patented design “are shaped and sized to 

closely follow each other and snugly fit together,” while in 
5 LEARNING CURVE v. MUNCHKIN

the accused device the interlocking of the cup and lid is 

achieved by the threaded subparts of the cup and lid. 

Consequently, the court granted summary judgment in 

favor of Munchkin. 

Learning Curve moved to alter or amend the judgment under Fed. R. Civ. P. 59. Learning Curve argued, 

inter alia, that the district court was wrong to conclude 

that “nearly continuous contact” required contact over 

more than 79 or 80% of the surface areas of the rim and 

lid. The court denied the motion. It explained that even 

if it had erred with respect to what degree of contact 

constituted “nearly continuous contact,” it would reach 

the same conclusion with respect to infringement. That 

was because, even adopting Learning Curve’s evidence as 

to the shape of the respective semi-circular arcs in the 

accused cups and lids, there was a “substantial difference 

in size between the respective radii, far more substantial 

than any ‘difference in degree’ that must be decided by 

the jury.” 

On appeal, Learning Curve argues that the district 

court incorrectly construed the claim term “semi-circular 

arcs of similar radii” by requiring that the lid and the rim 

of the cup body be in nearly continuous contact. Learning 

Curve asserts that the disputed claim term needed no 

construction and that under the plain meaning of that 

term, Munchkin’s accused cups infringed. Learning 

Curve also contends that, even accepting the district 

court’s construction of that claim term, the evidence as to 

whether the rims and lids in the accused cups were in 

nearly continuous contact presented a factual issue that 

precluded the grant of summary judgment. 

We need not address whether the district court was 

correct to interpret the term “semi-circular arcs of similar 
LEARNING CURVE v. MUNCHKIN 6

radii” to require nearly continuous contact between the 

cup and lid components throughout the circumference of 

the cup. Instead, we uphold the district court’s summary 

judgment ruling based on the alternative ground for 

decision set forth in the court’s opinion on Learning 

Curve’s motion for reconsideration. As the district court 

noted, the record shows that the semi-circular arcs defined by the groove in the lid and the rim of the main body 

of the accused cups have substantially different radii. 

Because of that difference, we agree with the district 

court that the accused cups do not satisfy the limitation in 

claim 1 of the ’784 patent requiring “semi-circular arcs of 

similar radii.” 

The district court examined the evidence proffered by 

Learning Curve’s expert, including the CT scans of the 

accused cups, and it concluded that the difference in the 

radii of the lids and the rims of the accused cups was so 

great that no reasonable jury could find the radii to be 

“similar.” The court observed that based on Learning 

Curve’s own evidence, at least one-fifth of the extent of 

the arc formed by the groove in the lid of the accused cups 

is not in contact with the corresponding arc formed by the 

rim of the main body of the cup. As Learning Curve’s own 

evidence demonstrates, that difference in congruence 

reflects a substantial difference in the radius of curvature 

of each of the two arcs. An exhibit offered by Learning 

Curve shows the difference in the two semi-circular arcs 

clearly. The CT scan of the accused cups with the lid 

screwed into place over the cup shows the arc of the cup 

rim with a relatively short radius and the corresponding 

arc of the groove of the lid above the cup rim with a 

substantially greater radius: 
7 LEARNING CURVE v. MUNCHKIN

 

Thus, as the district court observed, the evidence demonstrates “a substantial difference in size between the 

respective radii, far more substantial than any ‘difference 

in degree’ that must be decided by the jury.” 

Because the district court properly concluded, based 

on the difference in the radii of the two semi-circular arcs, 

that no reasonable jury could have found that the accused 

cups infringe the ’784 patent, the grant of summary 

judgment was appropriate. See Anderson v. Liberty 

Lobby, Inc., 477 U.S. 242, 248, 255-56 (1986); Absolute 

Software, Inc. v. Stealth Signal, Inc., 659 F.3d 1121, 1129-

30 (Fed. Cir. 2011); On Demand Mach. Corp. v. Ingram 

Indus., Inc., 442 F.3d 1331, 1345 (Fed. Cir. 2006). 

AFFIRMED