NOTE: This disposition is nonprecedential.

United States Court of Appeals 

for the Federal Circuit ______________________

HOIST FITNESS SYSTEMS, INC.,

Plaintiff-Appellant

v.

TUFFSTUFF FITNESS INTERNATIONAL, INC.,

Defendant-Appellee

______________________

2020-1047

______________________

Appeal from the United States District Court for the 

Central District of California in No. 5:17-cv-01388-AB-KK, 

Judge Andre Birotte, Jr.

______________________

Decided: October 2, 2020

______________________

LARA SUE GARNER, Gordon & Rees, San Diego, CA, argued for plaintiff-appellant. Also represented by SEAN 

DONOVAN FLAHERTY, MATTHEW G. KLEINER, SUSAN B.

MEYER.

 RUDOLPH A. TELSCHER, JR., Husch Blackwell LLP, St. 

Louis, MO, argued for defendant-appellee. Also represented by KARA RENEE FUSSNER, DAISY MANNING.

 ______________________

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2 HOIST FITNESS SYSTEMS v. TUFFSTUFF FITNESS

Before LOURIE, SCHALL, and DYK, Circuit Judges.

SCHALL, Circuit Judge.

Plaintiff-Appellant Hoist Fitness Systems, Inc. 

(“Hoist”) appeals from the September 10, 2019 final judgment of noninfringement entered in the United States District Court for the Central District of California in Hoist’s 

patent infringement suit against Defendant-Appellee TuffStuff Fitness International, Inc. (“TuffStuff”). Hoist Fitness Sys., Inc., v. TuffStuff Fitness Int’l, Inc., Final 

Judgment, No. 5:17-cv-01388-AB-KK, Dkt. No. 300 (C.D. 

Cal. Sept. 10, 2019), J.A. 24–25 (“Final Judgment”). Hoist 

sued TuffStuff for infringement of the following six patents: 

U.S. Patent No. 7,594,880 (“the 880 patent”); U.S. Patent 

No. 7,563,209 (“the ’209 patent”); U.S. Patent No. 7,549,949 

(“the ’949 patent”); U.S. Patent No. 7,654,938 (“the ’938 patent”); U.S. Patent No. 7,976,440 (“the ’440 patent”); and 

U.S. Patent No. 7,993,251 (“the ’251 patent”). Judgment 

was entered pursuant to the parties’ stipulation following 

the district court’s final pronouncement on claim construction at a pretrial status conference held on September 9, 

2019. Joint Stipulation for Entry of Judgment, No. 5:17-

cv-01388-AB-KK, Dkt. No. 298 (C.D. Cal. Sept. 10, 2019), 

J.A. 26–29 (“Joint Stipulation”). Because we discern no error in the district court’s claim construction, we affirm. 

BACKGROUND

I.

Hoist’s patents are directed to “exercise machine[s] 

with a pivoting user support.” ’938 patent col. 1 ll. 15–17. 

The patents state that the “user support frame moves in 

conjunction with the exercise arm” so the user experiences 

a “more natural feeling exercise movement that more 

closely replicates the movement found in the corresponding 

free weight exercise.” Id. at col. 4 ll. 11–16. The patents 

describe and illustrate two general kinds of mechanisms 

that may be used to pivotally mount a user support frame 

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HOIST FITNESS SYSTEMS v. TUFFSTUFF FITNESS 3

onto an exercise machine’s main frame to achieve this objective: (1) a single pivot;1 or (2) a “four-bar linkage,” which 

is a multiple part pivot assembly having multiple pivots.2

Such four-bar linkage mechanisms have a “theoretical” 

pivot axis that is a point reflecting a composite center of 

rotation for the user support frame. See ’938 patent col. 6 

ll. 6–17; ’209 patent col. 6 ll. 42–50. As explained in the 

’938 patent:

The multiple part pivot assembly defines a theoretical pivot axis of the user support pivotal motion. 

As illustrated in FIGS. 3 and 4, the theoretical 

pivot axis 84 is located below the user support, and 

a theoretical gravitational center line 74 of the pivotal motion extending through pivot axis 84 also 

extends through the user support frame 15. The 

location of the theoretical pivot axis 84 can be determined from the start and end positions of the 

two pivot links 60 and 62, and is the point of intersection of the centerline A of the pivotal movement 

of the forward link 62 and the centerline B of the 

pivotal movement of the rear link 60, as indicated 

in FIGS. 3 and 4. 

’938 patent col. 6 ll. 6–17. For purposes of addressing the 

claim construction issues presented in this appeal, we consider claim 22 of the ’880 patent and claim 1 of the ’938 

patent representative of the relevant claims of the six Hoist 

patents at issue. Claim 22 of the ’880 patent recites:

1 See, e.g., ’880 patent col. 10 l. 51–col. 22 l. 63 & Figs. 

5–32; ’949 patent col. 3 l. 13–col. 7 l. 11 & Figs. 1–6.

2 See, e.g., ’938 patent col. 5 l. 63–col. 6 l. 17 & Figs. 

1–4; ’949 patent col. 7 l. 12–col. 8 l. 26 & Figs. 7A–8.

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4 HOIST FITNESS SYSTEMS v. TUFFSTUFF FITNESS

22. An exercise machine, comprising: 

a main frame;

a user support frame pivotally mounted relative to 

the main frame for rotation about a user support 

pivot axis, the user support pivot axis defining a 

vertical, gravitational center line, the user support 

frame comprising one moving part of the machine;

the user support frame having at least a primary 

support and a secondary support for supporting 

spaced positions on a user’s body throughout an exercise movement, the primary support comprising 

a seat pad and the secondary support comprises a 

leg support which travels in the same direction as 

the primary support throughout an exercise movement;

a user engagement device movably mounted on one 

of the frames for engagement by the user in performing exercises, the user engagement device 

comprising a second moving part of the machine;

a connecting link linking movement of the user engagement device to movement of the user support 

frame, the connecting link comprising a third moving part of the machine; and

a load for resisting movement of at least one of the 

moving parts of the machine; whereby movement 

of the user engagement device in an exercise movement simultaneously moves the user support frame 

between a start position and an end position, the 

user support pivot axis being positioned such that 

portions of the combined weight of the user and 

user support frame are distributed on each side of 

the gravitational center line of the user support 

pivot axis in both the start and end position and

only a portion of the combined weight passes 

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HOIST FITNESS SYSTEMS v. TUFFSTUFF FITNESS 5

through the gravitational center line during the exercise movement.

’880 patent col. 28 l. 44–col. 29 l. 14. Claim 1 of the ’938 

patent recites:

1. An exercise machine, comprising: 

a stationary main frame having an upper end, a 

lower end, a first end, and a second end;

a user support frame which is adapted to support a 

user in an exercise ready position on the main 

frame;

a multiple part pivot assembly pivotally mounting 

the user support frame relative to the main frame 

and having multiple pivots which together control 

pivotal movement of the user support frame in an 

arcuate exercise movement path about a central 

pivot axis;

the user support frame having at least a primary 

support and a secondary support which support 

spaced positions on a user’s body throughout an exercise movement, the secondary support being secured at a fixed and unchanging angular 

orientation relative to the primary support at least 

throughout an exercise movement, the primary 

support supporting the majority of a user’s weight 

in the start position of the support frame;

a user engagement device movably mounted relative to the frames for engagement by the user in 

performing exercises;

a connecting linkage which translates movement of 

the user engagement device during an exercise to 

movement of the user support frame;

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6 HOIST FITNESS SYSTEMS v. TUFFSTUFF FITNESS

a load for resisting movement of at least one of the 

user support, user engagement device, and connecting linkage; and

the central pivot axis of the pivotal movement of 

the user support frame being positioned such that 

a gravitational center line which extends vertically 

through the central pivot axis also extends through 

the user support frame during at least part of the

arcuate exercise movement path of the user support frame and only a portion of the combined 

weight of the user and user support frame passes 

through the gravitational center line during an exercise.

’938 patent col. 9 l. 56–col. 10 l. 25. 

II.

On April 3, 2017, Hoist sued TuffStuff in the Southern 

District of California, alleging infringement of claim 22 of 

the ’880 patent; claims 6 and 21 of the ’209 patent; claims 

2, 8, and 23 of the ’949 patent; claims 1, 12, and 13 of the 

’938 patent; claims 5, 12, 13, and 20 of the ’440 patent; and 

claims 54 and 71 of the ’251 patent. Compl., No. 3:17-cv00670, Dkt. No. 1 (S.D. Cal. Apr. 3, 2017) at 6–11, J.A. 330–

35. The case was subsequently transferred to the Central 

District of California. 

The exercise devices which Hoist accused of infringement are part of TuffStuff’s “Bio-Arc” line of products. The 

TuffStuff devices have a user support that is mounted on a 

pivot that is, in turn, mounted on a sliding carriage that 

translates back and forth along a linear shaft during the 

exercise movement. Def.’s Not. of Mot. and Mot. for Summ. 

J, Ex. 17, Decl. of D. Penado, No. 5:17-cv-01388-AB-KK, 

Dkt. No. 144-17 (C. D. Cal. Dec. 26, 2018) at 2–16, J.A. 

3773–87. The accused TuffStuff devices have structure 

that both pivots and slides, resulting in a “combined elliptical movement.” Pl.’s Notice of Mot. and Mot. for Prelim. 

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HOIST FITNESS SYSTEMS v. TUFFSTUFF FITNESS 7

Inj. to Enjoin Infringement of the ’880 Patent, No. 5:17-cv01388-AB-KK, Dkt. No. 33 (C.D. Cal. Sept. 5, 2017) at 16–

17, J.A. 481–82. 

III.

In the course of the proceedings below, the district 

court construed a number of claim terms. The joint stipulation for entry of judgment of noninfringement, however, 

was based upon the court’s construction of just three terms: 

“pivotally mounted relative to the main frame,” “pivotally 

mounting the user support frame relative to the main 

frame,” and “pivotally mounted on the main frame.” Joint 

Stipulation at 2, J.A. 27. Accordingly, it is to these related 

terms that we direct our attention. The term “pivotally 

mounted relative to the main frame” appears in independent claim 22 of the ’880 patent in the limitation “a user support frame pivotally mounted relative to the main frame for 

rotation about a user support pivot axis, the user support 

pivot axis defining a vertical, gravitational center line.” 

’880 patent col. 28 ll. 47–50.3 The term “pivotally mounting 

the user support frame relative to the main frame” appears 

in independent claim 1 and, through their dependency on 

claim 1, claims 12 and 13 of the ’938 patent, in the limitation “a multiple part pivot assembly pivotally mounting the 

user support frame relative to the main frame and having 

multiple pivots which together control pivotal movement of 

the user support frame in an arcuate exercise movement 

path about a central pivot axis.” ’938 patent col. 9 ll. 61–

3 The term “pivotally mounted relative to the main 

frame” also appears in independent claims 6 and 21 of the 

’209 patent, independent claims 2, 8, and 23 of the ’949 patent, and independent claims 5 and 20 of the ’440 patent. 

See ’209 patent col. 15 ll. 31, 54–57 & col. 16 l. 66; ’949 patent col. 12 ll. 14 & 63, col. 13 ll. 29 & 42–43, col. 15 l. 19; 

’440 patent col. 11 ll. 47–48 & col. 14 ll. 51–52. 

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8 HOIST FITNESS SYSTEMS v. TUFFSTUFF FITNESS

65 & col. 11 ll. 7–12.4 The term “pivotally mounted on the 

main frame” appears in independent claims 54 and 71 of 

the ’251 patent in the limitation “a user support frame pivotally mounted on the main frame which supports a user 

in an exercise position.” ’251 patent col. 21 ll. 28–29, col. 

22 ll. 62–63. Where appropriate, we refer to these as the 

“pivotally mounted/mounting terms.”

In a claim construction order issued on October 24, 

2018, the district court determined that no construction 

was necessary for the pivotally mounted/mounting terms. 

Claim Construction Order, No. 5:17-cv-01388-AB-KK, Dkt. 

No. 111 (C.D. Cal. Oct. 24, 2018) at 15, J.A. 44. The court 

observed, though, that construing “pivot” and “rotation” to 

include “more than generally ‘concentric’ movement would 

effectively destroy the meaning of those terms as they were 

understood by the patent applicant.” Id. at 14, J.A. 43.

On August 27, 2019, two weeks before the date scheduled for trial, the district court addressed claim construction again, when it ruled on the parties’ respective motions 

in limine. See Order Regarding Parties’ Mots. in Lim. and

Construing Additional Disputed Claim Terms, No. 5:17-cv01388–AB-KK, Dkt. No. 279 (C.D. Cal. Aug. 27, 2019) (“August 27, 2019 Order”), J.A. 95. The court (1) construed 

“pivotally mount[ed]/[ing] relative to the main frame” as 

“mount[ed]/[ing] such that the overall movement relative 

to the main frame is generally concentric; provided, however, that movement need not be perfectly circular;” 

(2) construed “pivotally mounted on the main frame” as 

“mounted, either directly or indirectly, to the main frame 

such that the overall movement relative to the main frame 

is generally concentric; provided, however, that movement 

4 The term “pivotally mounting the user support 

frame relative to the main frame” also appears in independent claims 12 and 13 of the ’440 patent. ’440 patent 

col. 13, ll. 13–14 & 54–55. 

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need not be perfectly circular;” and (3) construed “arcuate 

exercise movement path about a central pivot” as an “overall movement path that is generally concentric about a single central pivot point; provided, however, that movement 

need not be perfectly circular around the central pivot 

point.” Id. at 7, J.A. 101. In its order, the court stated that 

it would permit Hoist’s expert, Steven M. Lenz, to serve a 

supplemental report responding to its claim construction. 

Id. at 8, J.A. 102. Hoist served its expert’s supplemental 

report on September 6, 2019. J.A. 9340. 

On September 9, 2019, the day before trial was scheduled to begin, the court held a status conference. At the 

conference, the court provided further guidance regarding 

construction of the pivotally mounted/mounting terms, in 

light of its view that “concentric is more synonymous with 

circular” as opposed to “hav[ing] a common center or to be 

aligned.” J.A 9439–40. The court stated:

All right. I have considered the argument of both 

counsel in the case. Look, the Court—I guess I take 

the view that the supplemental expert report has

just interpreted the term “concentric” too broadly. 

The plaintiffs—I guess, if I understand Lenz’s report correctly, concentric means to have a common 

center or to be aligned, just looking at the report 

again. Defense believes concentric is more synonymous with circular. Quite frankly, the Court 

agrees with the defense on this one based on the 

Court’s orders and the patents themselves.

When you look at the claim language, it requires 

pivotal movement, and the claim term we have 

been construing here is “pivotally mounted.” I 

think the ordinary meaning of a pivot is a fixed 

point with movement around that point. And so, 

by construing the term to include generally concentric movement, we were trying to clarify that the 

patents that described this four-bar linkage 

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10 HOIST FITNESS SYSTEMS v. TUFFSTUFF FITNESS

assembly embodiment would not require a perfectly circular motion. But I think the plaintiff’s 

interpretation as concentric is something much 

broader than circular goes beyond these examples 

and I think beyond the meaning of pivot.

Id.

The effect of this pronouncement was to leave the parties with a claim construction that combined what the court 

had said in its claim construction order of October 24, 2018, 

and at the September 9 status conference. Accordingly, the 

pivotally mounted/mounting terms were effectively construed to mean:

mount[ed]/[ing] such that the overall movement 

relative to the main frame is generally concentric 

[“concentric” is “more synonymous with circular” 

rather than meaning “having a common center”]; 

provided, however, that movement need not be perfectly circular.5

In view of its claim construction, the district court 

struck the supplemental report of Hoist’s expert.6 

5 Similarly, the term “pivotally mounted on the main 

frame” was effectively construed to mean:

mounted, either directly or indirectly, to the main 

frame such that the overall movement relative to 

the main frame is generally concentric [“concentric” is “more synonymous with circular” rather 

than meaning “having a common center”]; provided, however, that movement need not be perfectly circular. 6 In his supplemental report, Hoist’s expert Mr. Lenz 

stated that a person of ordinary skill in the art “would understand “concentric” as “having a common center,” 

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On September 10, based upon the claim construction 

advanced by the district court at the September 9 status 

conference, the parties stipulated to entry of judgment of 

noninfringement in favor of TuffStuff. That same day, the 

court entered final judgment in accordance with the stipulation. Thereafter, Hoist timely appealed. We have jurisdiction pursuant to 28 U.S.C § 1295(a)(1).

DISCUSSION

I.

Claim construction is ultimately an issue of law that 

we review de novo. Teva Pharm. USA, Inc. v. Sandoz, Inc., 

574 U.S. 318, 325–26 (2015). “[W]hen the district court reviews only evidence intrinsic to the patent (the patent 

claims and specifications, along with the patent’s prosecution history), the judge’s determination will amount solely 

to a determination of law, and the Court of Appeals will 

review that construction de novo.” Id. at 331. We review 

“regardless of the object or shape to which the common center regards.” J.A. 9344. Mr. Lenz stated:

In other words, two bodies of dissimilar or nonsymmetrical shapes or sizes may nonetheless be 

aligned in a concentric manner. 

For example, a square and a triangle are concentrically aligned if they have a common center. 

Similarly, the overall rotational motion of a body is 

“concentric” arounds its center of rotation, or pole 

of planar displacement, despite the fact that not all 

points on said body need rotate precisely around 

the same center of rotation. Rather, when considering the rotation of the body as a whole, the center 

of rotation [is] an average point around which the 

body moves. 

J.A. 9344. 

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the district court’s underlying factual findings for clear error. Id. at 325–33. 

Claim terms are generally given their ordinary and 

customary meaning as understood by a person of ordinary 

skill in the art. Phillips v. AWH Corp., 415 F.3d 1303, 

1312–13 (Fed. Cir. 2005) (en banc). The person of ordinary 

skill in the art is “deemed to read the claim term not only 

in the context of the particular claim in which the disputed 

term appears, but in the context of the entire patent, including the specification.” Id. at 1313.

II.

Hoist argues that the district court erred when it construed the pivotally mounted/mounting terms to require 

“overall movement” that is “generally concentric” and in 

concluding that “concentric” is “more synonymous with circular” rather than meaning “having a common center.” Appellant’s Br. 38.7 In so doing, Hoist contends, the district 

7 We have considered and find no merit to TuffStuff’s 

argument that Hoist withdrew from the litigation its allegations of infringement with respect to certain patents and 

claims prior to, and unrelated to, the stipulation. Hoist did 

not officially “withdraw” its patents or claims, but merely 

selected “representative” claims to present to the jury upon 

the court’s request that it do so. J.A. 9273–74. Indeed, all 

of the patents and claims at issue were included in the parties’ joint proposed pre-trial conference order. Proposed Final Pre-Trial Conf. Order, No. 5:17-cv-01388-AB-KK, Dkt. 

No. 239, at 5 (C.D. Cal. Sept. 2, 2019). Further, the parties’ 

stipulation for entry of final judgment specifically identified each of the six Hoist patents at issue as having been 

asserted. Joint Stipulation at 2, J.A. 27. Hoist thus did not 

cease to litigate the patents or claims at issue, and they are 

all properly before us on appeal. See Alcon Rsch. Ltd. v. 

Barr Labs., Inc., 745 F.3d 1180, 1193 (Fed. Cir. 2014) 

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court “improperly imported additional movement path restrictions” into its constructions of the pivotally 

mounted/mounting terms. Id. at 42. Hoist asserts that, 

while claims that recite a pivot axis do require “generally 

concentric” movement about the pivot axis,8 claims directed to pivotally mounted/mounting have no requirement 

of concentricity. Id. at 44–45. Finally, Hoist argues that 

the court’s claim construction improperly limits movement 

of the user support to the movement disclosed in the case 

of the single pivot embodiment. Hoist states that “[i]f an 

embodiment’s user support were mounted using one physical pivot and if that single pivot were fixed in place, the 

movement of the user support would be only circular.” Id.

at 46. Hoist continues, however, that “[t]he Asserted 

Claims are not so limited.” Id. Hoist concludes its argument by summarizing that:

The “pivotally mounted[/ing]” terms have no special meaning beyond their plain meaning. The 

specification and claim language make[ ] clear that 

the claims merely require a pivotal mounting relative to or on the main frame, which is the plain

meaning. The term makes no further reference to, 

and places no further limitation on, the shape or 

nature of the resulting movement path.

Id. at 48. 

TuffStuff responds that the district court correctly construed the pivotally mounted/mounting terms. It states 

that the district court properly construed “pivotally 

mounted/mounting relative to the main frame” as 

(citing SanDisk Corp. v. Kingston Tech. Co., 695 F.3d 1348, 

1353 (Fed. Cir. 2012)). 

8 E.g., claim 22 of the ’880 patent, claim 6 of the ’209 

patent, claims 2, 8, and 23 of the ’949 patent, and claim 1 

and its dependent claims 12 and 13 of the ’938 patent.

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requiring “pivotal motion” (i.e., generally concentric/circular motion) in relationship to the main frame. Appellee’s 

Br. 47. TuffStuff argues that the patent specifications, the 

“single best guide” to claim construction under Phillips, 

415 F.3d at 1315, “overwhelmingly” support the proposition that a mounting structure that produces “pivotal” motion is one that produces a circular motion around a fixed 

point. Appellee’s Br. 47, 50–51. In advancing that argument, TuffStuff points to several places in the ’209 and ’949

patent specifications where it is stated that the four-bar 

pivot linkage “duplicates” the movement of a single pivot. 

Id. at 8–10 & 48–50.

III.

We find no error in the district court’s claim construction. As noted above, claim terms are generally given their 

ordinary and customary meaning as understood by a person of ordinary skill in the art, who is “deemed to read the 

claim term not only in the context of the particular claim 

in which the disputed term appears, but in the context of 

the entire patent, including the specification.” Phillips, 

415 F.3d at 1313. Here, the specifications compel a construction of “pivotally moun[ed]/[ing]” that requires generally concentric motion, where concentric is “more 

synonymous with circular” than “having a common center.” 

Hoist does not dispute that a single, fixed, physical 

pivot accomplishes “generally circular” movement. See Appellant’s Br. 46. Indeed, Hoist’s expert, Mr. Lenz, confirmed that a single pivot mounted on a stationary base 

would move in “essentially” a “circular motion” around its 

pivot axis. J.A. 2618. Instead, however, Hoist points to the 

four-bar linkage as an embodiment that it claims illustrates movement that is not generally circular and instead 

“always includes a lateral component in addition to a pivotal component.” Oral Arg. at 4:19–5:05 (July 6, 2020), 

available at http://oralarguments.cafc.uscourts.gov/default.aspx?fl=2020-1047.mp3. 

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We do not read the specifications to encompass lateral 

movement in the manner Hoist argues. Rather, the specifications for the Hoist patents repeatedly state that the 

four-bar linkage system “duplicates” the movement pattern 

of a single point pivot, while providing additional location

options for the theoretical pivot axis of the four-bar linkage 

that are not possible with a single point pivot. Specifically, 

the specification of the ’209 patent states:

The advantage of the four-bar pivot system with 

the theoretical pivot is that it duplicates the movement pattern of a single point pivot that might normally be located in an area impossible to access due 

to either structural or user interference, so that a 

desired movement pattern may be achieved while 

keeping the moving parts of the pivot mount beneath the user support. 

’209 patent col. 6 ll. 42–48 (emphasis added); see also id. at 

col. 7 ll. 7–11 (“[T]he four-bar pivoting linkage system . . . 

duplicates the movement pattern of a single point pivot that 

would otherwise be located underground, beneath the machine.”) (emphasis added); col. 13 ll. 56–62 (explaining that 

a four-bar pivoting linkage system “can allow a desired pivoting movement to be achieved when a single pivot point 

for producing the same motion may be located in an area 

impossible to access due to either structural or user interference.”) (emphasis added). 

The ’949 patent similarly states that a four-bar linkage 

recreates the movement of a single pivot when a pivot cannot be placed at the desirable location:

A four bar pivot linkage beneath the user support 

can be arranged to produce movement equivalent to 

a single pivot at an inaccessible location . . . .

’949 patent col. 2 ll. 10–15 (emphasis added). 

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The theoretical pivot . . . is the position the user 

support would pivot about if a single pivot were 

used in order to obtain the same movement pattern.

Id. at col. 8 ll. 6–9 (emphasis added). The ’251 patent incorporates by reference the patent application that ultimately issued as the ’949 patent and, in addition, uses the 

terms “concentric” and “circular” synonymously. ’251 patent col. 1 ll. 53–55 (“Since the exercise arms had only one 

pivot, they could only move in a concentric or circular pattern.”). 

Further, like the ’209 patent and the ’949 patent, the 

’880 patent, the ’938 patent, and the ’440 patent each describe a theoretical pivot axis for the four-bar linkage that 

is stationary, thereby resulting in generally concentric motion. E.g., ’880 patent col 9 l. 62–col. 10 l.1 & Figs. 1–4, ’938 

patent col. 6 ll. 6–17, col. 7 ll. 55–57 & Figs. 1–4, ’440 patent

col. 9 ll. 52–55. 

We note that, to the extent the movement of a four-bar 

linkage is not identical to a single pivot, the district court 

addressed this through its construction that the movement 

need be “generally” concentric but need not be “perfectly 

circular.” See J.A. 9439–40; August 27, 2019 Order at 7, 

J.A. 101. At the same time, though, the Hoist specifications do not support a construction that goes beyond generally concentric, or generally circular, motion. 

Based upon the foregoing, we hold that the district 

court did not err in it claim construction.9

9 Additionally, we find no error in the district court’s 

decision to strike Mr. Lenz’s supplemental report. The 

court struck the supplemental report in part because it determined that Mr. Lenz interpreted the term “concentric”

too broadly. As we have affirmed the district court’s claim 

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CONCLUSION 

Because we agree with the district court’s construction 

of the pivotally mounted/mounting claim terms, we affirm 

the judgment of noninfringement of the Hoist patents in 

favor of TuffStuff.

AFFIRMED

construction, for the reasons discussed above, we also agree 

that the report was properly stricken.

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