Case 1:17-cv-00770-JDW Document 448 Filed 08/21/24 Page 1 of 21 PageID #: 40700
`
`IN THE UNITED STATES DISTRICT COURT
`FOR THE DISTRICT OF DELAWARE
`
`WIRTGEN AMERICA, INC.,
`
`
`
`
`Plaintiff,
`
`
`
`v.
`
`
`CATERPILLAR, INC.,
`
`
`
`
`
`Defendant.
`
`
`
`
`
`
`Case No. 1:17-cv-00770-JDW
`
`
`
`
`
`
`
`
`
`
`
`MEMORANDUM
`
`This patent litigation between Wirtgen America, Inc. and Caterpillar, Inc. concerns
`
`patents for road construction and repair. A jury concluded that Caterpillar willfully
`
`infringed five of Wirtgen’s patents: (1) U.S. Patent No. 7,828,309 (‘309 Patent); (2) U.S.
`
`Patent No. 7,530,641 (‘641 Patent); (3) U.S. Patent No. 9,656,530 (‘530 Patent); (4) U.S.
`
`Patent No. 7,946,788 (‘788 Patent); and (5) U.S. Patent No. 8,424,972 (‘972 Patent).
`
`Caterpillar asserts equitable defenses as to the ‘309, ‘530, and ‘788 Patents based on
`
`claims of judicial estoppel, prosecution laches, and collateral estoppel.
`
`“Laches and estoppel are equitable defenses, committed to the sound discretion
`
`of the trial court.” Hemstreet v. Computer Entry Sys. Corp., 972 F.2d 1290, 1292 (Fed. Cir.
`
`1992). Those defenses turn on factual determinations. See id. After consideration of the
`
`evidence presented and relevant law, I make the following findings of fact and conclusions
`
`

`

`Case 1:17-cv-00770-JDW Document 448 Filed 08/21/24 Page 2 of 21 PageID #: 40701
`
`of law pursuant to Fed R. Civ. P. 52(a) with respect to those equitable defenses.1 Because
`
`Caterpillar asserts a different defense as to each patent, I make the findings of fact and
`
`conclusions of law on a patent-by-patent basis.
`
`I.
`
`‘309 PATENT
`
`A.
`
`1.
`
`Findings Of Fact
`
`The ‘309 Patent discloses a stability pattern for road milling machines,
`
`which is useful when those machines travel on uneven terrain. Claim 29 recites a
`
`machine with “a four sided stability pattern having a widest transverse dimension,
`
`transverse to the forward direction of the chassis, which widest transverse dimension
`
`falls within a footprint of the working roller or rotor.” (‘309 Patent at 14:33-36.)
`
`2.
`
`Claim 29 has two component parts: (a) there’s a stability pattern, and (b)
`
`that pattern’s widest dimension occupies a specific position relative to the machine.
`
`3.
`
`In an IPR proceeding, Caterpillar challenged the validity of Claim 29 under
`
`the theory that it was obvious as an inherent teaching of two prior art references
`
`(“Swisher” and “Neumeier”). In that proceeding, Wirtgen argued that Caterpillar didn’t
`
`meet its burden to establish obviousness. Wirtgen contended that Swisher and
`
`Neumeier didn’t necessarily disclose Claim 29’s limitation.
`
` 
`1 Caterpillar also asks me to find that the ‘268 Patent is unenforceable because of
`equitable and absolute intervening rights. The jury determined that the ‘268 Patent is
`invalid and not infringed, so I will not rule on this aspect of Caterpillar’s Motion unless I
`grant Wirtgen’s renewed judgment as a matter of law regarding that patent.
`
` 
`
`2
`
`

`

`Case 1:17-cv-00770-JDW Document 448 Filed 08/21/24 Page 3 of 21 PageID #: 40702
`
`4.
`
`The PTAB agreed with Wirtgen. It held that “the evidence before us as to
`
`whether the four-sided stability pattern is inherent in the Swisher/Neumeier
`
`combination … and whether the widest transverse direction of the pattern necessarily
`
`falls within the milling drum’s footprint, is that the evidence is uncertain in an area
`
`where the law urges caution and clarity.” (D.I. 369-12 at 53-54.) The PTAB went on to say
`
`that the limitation may have been disclosed in prior art, but as a matter of law, that can’t
`
`establish obviousness. (Id. at 54 (citing PAR Pharm., Inc. v. TWI Pharms., Inc., 773 F.3d
`
`1186, 1195 (Fed. Cir. 2014)). The PTAB therefore held Claim 29 of the ‘309 Patent not
`
`unpatentable over Caterpillar’s Swisher/Neumeier combination.
`
`5.
`
`At trial in this case, Wirtgen’s expert Dr. Lumkes opined that the Accused
`
`Machines practice Claim 29 of the ‘309 Patent. He testified that the Accused Machines’
`
`hydraulic coupling produces a four-sided stability pattern and that their stability pattern
`
`falls within the rotor. In his view, the Accused Machines’ stability pattern “had to occur at
`
`the midpoints of the legs, since all the cylinders are equal value … [which] is going to
`
`cause that pivot point to be in the middle of those legs.” (Tr.2 596:4-24.)
`
`6.
`
`Dr. Lumkes evaluated a computer-aided design file (“CAD”) of the Accused
`
`Machines to determine that the stability pattern falls within the rotor’s footprint. The
`
`CAD model that Caterpillar provided is a “very detailed, very large file, down to the nuts
`
`and washers and bolts on the machine” which is essentially “a blueprint for which the
`
` 
`2 All citations to “Tr.” refer to the trial transcript.
`
` 
`
`3
`
`

`

`Case 1:17-cv-00770-JDW Document 448 Filed 08/21/24 Page 4 of 21 PageID #: 40703
`
`machine is built from.” (Tr. 597:3-7.) It allowed Dr. Lumkes to measure the dimensions of
`
`one of the Accused Machines, the PM620. Dr. Lumkes also inspected certain Caterpillar
`
`machines and took measurements “to confirm that the dimensions that were on the
`
`CAD file … were correct.” (Tr. 601:14-17.)
`
`7.
`
`When asked on cross-examination, Dr. Lumkes did not agree that the
`
`claimed stability pattern is inherent from any cold milling machine. (Tr. 649:10-16.)
`
`B.
`
`8.
`
`Conclusions Of Law
`
`Judicial estoppel “prevents a party from prevailing in one phase of a case
`
`on an argument and then relying on a contradictory argument to prevail in another
`
`phase.” New Hampshire v. Maine, 532 U.S. 742, 749 (2001) (internal quotation and
`
`citation omitted). Third Circuit law governs this analysis in a patent case. See Egenera,
`
`Inc. v. Cisco Sys., Inc., 972 F.3d 1367, 1378 (Fed. Cir. 2020).
`
`9.
`
`Judicial estoppel is often “the harshest remedy.” Montrose Med. Grp.
`
`Participating Sav. Plan v. Bulger, 243 F.3d 773, 784 (3d Cir. 2001). As a result, it is only
`
`appropriate when there were (a) irreconcilably inconsistent positions, (b) adopted in bad
`
`faith, and (c) a showing that estoppel addresses the harm and no lesser sanction is
`
`sufficient. See G-I Holdings, Inc. v. Reliance Ins. Co., 586 F.3d 247, 262 (3d Cir. 2009), as
`
`amended (Dec. 4, 2009).
`
`10.
`
`As a threshold matter, Wirtgen argues that Caterpillar has forfeited its
`
`right to raise a judicial estoppel argument. The “only legitimate” purpose of judicial
`
` 
`
`4
`
`

`

`Case 1:17-cv-00770-JDW Document 448 Filed 08/21/24 Page 5 of 21 PageID #: 40704
`
`estoppel is to “protect the courts rather than the litigants.” Bulger, 243 F.3d at 785
`
`(emphasis in original). Courts may protect themselves by raising judicial estoppel sua
`
`sponte even after a litigant has forfeited that argument. See, e.g., 1st Source Bank v.
`
`Neto, 861 F.3d 607, 612 (7th Cir. 2017); Krystal Cadillac-Oldsmobile GMC Truck, Inc. v.
`
`Gen. Motors Corp., 337 F.3d 314, 325 (3d Cir. 2003) (judicial estoppel raised sua sponte).
`
`I will therefore reach the merits of Caterpillar’s argument.
`
`11. Wirtgen didn’t assume irreconcilably inconsistent positions between the
`
`IPR challenge and this litigation. In the IPR, Wirtgen argued that a hypothetical machine
`
`based on Swisher and Neumeier would not necessarily result in a stability pattern with
`
`its widest transverse dimension falling within the rotor. In this case, Wirtgen argued that
`
`the Accused Machines did in fact have a stability pattern with its widest transverse
`
`dimension falling within the rotor.
`
`12.
`
`In the IPR, Wirtgen countered Caterpillar’s obviousness argument with the
`
`contention that prior art didn’t inherently disclose Claim 29’s limitations. Inherency “may
`
`supply a missing claim limitation in an obviousness analysis.” PAR Pharm., Inc., 773 F.3d
`
`at 1194-95. But this doctrine poses a high bar. See id. at 1195. The party advancing an
`
`inherency argument must show that “the limitation at issue is the ‘natural result’ of the
`
`combination of prior art elements.” See id. (quoting In re Oelrich, 666 F.2d 578, 581
`
`(C.C.P.A. 1981)). “[P]robabilities or possibilities” won’t suffice. Id.
`
` 
`
`5
`
`

`

`Case 1:17-cv-00770-JDW Document 448 Filed 08/21/24 Page 6 of 21 PageID #: 40705
`
`13. Wirtgen argued in the IPR that Caterpillar didn’t meet this burden because
`
`Swisher and Neumeier didn’t necessarily disclose Claim 29’s limitation. However, in this
`
`litigation, Wirtgen’s expert opined that the Accused Machines meet this claim limit.
`
`14.
`
`Caterpillar argues that Dr. Lumkes adopted an argument that looks a lot
`
`like inherency, which creates an inconsistency. This argument is unconvincing. First, it
`
`oversimplifies Dr. Lumkes’s analysis. Dr. Lumkes based his infringement finding on his
`
`assessment of a CAD file and inspection of the Accused Machines. In his opinion, the
`
`CAD file revealed certain features about the legs and cylinders in the Accused Machines,
`
`which allowed him to determine the stability pattern of those machines.
`
`15.
`
`Caterpillar says that it’s a leap of logic for Dr. Lumkes to find an infringing
`
`stability pattern just from those legs and cylinders when the ‘309 Patent cites instances
`
`where the stability pattern wouldn’t automatically result. It also says that Dr. Lumkes
`
`didn’t rule out those scenarios. But this disagreement with Dr. Lumkes’s method or
`
`conclusions doesn’t support the application of judicial estoppel. Instead, Caterpillar
`
`could, and did, point out to the jury why (in its estimation) Dr. Lumkes’s opinion rested
`
`on a flawed foundation.
`
`16.
`
`Second, Caterpillar’s argument overstates the scope of Dr. Lumkes’s
`
`conclusion. Dr. Lumkes didn’t conclude that a stability pattern with its widest transverse
`
`dimension falling within the rotor would be present in any hypothetical machine, only
`
`that it is present in the Accused Machines. That’s clear from Dr. Lumkes’s testimony,
`
` 
`
`6
`
`

`

`Case 1:17-cv-00770-JDW Document 448 Filed 08/21/24 Page 7 of 21 PageID #: 40706
`
`where he disclaimed that a four-sided stability pattern is necessarily inherent in “any
`
`cold milling machine.” (Trial Tr. 649:10-16.)
`
`17.
`
`“Judicial estoppel is … not intended to eliminate all inconsistencies no
`
`matter how slight or inadvertent they may be.” Krystal Cadillac-Oldsmobile GMC Truck,
`
`Inc., 337 F.3d at 319. It does not apply with respect to the ‘309 Patent.
`
`II.
`
`‘530 PATENT
`
`A.
`
`18.
`
`Findings Of Fact
`
`The ‘530 Patent is a continuation of U.S. Patent No. 9,010,871 (‘871 Patent),
`
`which itself is a continuation of U.S. Patent No. 8,113,592 (‘592 Patent) (together, “the
`
`‘530 Patent family”).
`
`19.
`
`20.
`
`The application for the ‘592 Patent was initiated on March 12, 2008.
`
`In 2010, during the prosecution of the ‘592 Patent, the Patent Office cited
`
`a Caterpillar prior art patent application disclosing legs that adjust together as if they
`
`were a single central jack. In response, Wirtgen claimed a road construction machine
`
`with “each” “individually adjustable legs.”
`
`21.
`
`22.
`
`The application for the ‘871 Patent was initiated on January 17, 2012.
`
`For all claims granted in the ‘592 and ‘871 Patents, the invention required
`
`each leg of the road construction machine to be “individually adjustable.”
`
`23.
`
`The application for the ‘530 Patent was initiated on April 10, 2015.
`
` 
`
`7
`
`

`

`Case 1:17-cv-00770-JDW Document 448 Filed 08/21/24 Page 8 of 21 PageID #: 40707
`
`24.
`
`In December 2016, Wirtgen acquired a newly released Caterpillar road
`
`milling machine, the PM620. On March 14, 2017, Wirtgen acquired and then analyzed a
`
`Caterpillar PM622.
`
`25. On March 23, 2017, Wirtgen amended the ‘530 Patent’s application. It
`
`removed the requirement that each leg of the machine be individually adjustable. What
`
`resulted was a broader claim scope—each claimed machine’s legs need only be
`
`“adjustable” (and not “individually adjustable”).
`
`26.
`
`The ‘530 Patent family received roughly three years of Patent Term
`
`Adjustments to account for Patent Office delays. The ‘592 Patent received 688 days, the
`
`‘871 Patent received 239 days, and the ‘530 Patent received 181 days.
`
`B.
`
`27.
`
`Conclusions Of Law
`
`Prosecution laches may “render a patent unenforceable when it has issued
`
`only after an unreasonable and unexplained delay in prosecution that constitutes an
`
`egregious misuse of the statutory patent system under a totality of the circumstances”
`
`and that delay causes prejudice to the accused infringer. Hyatt v. Hirshfeld, 998 F.3d
`
`1347, 1360, 1362 (Fed. Cir. 2021). It requires proving “(1) the patentee's delay in
`
`prosecution must be unreasonable and inexcusable under the totality of circumstances
`
`and (2) the accused infringer must have suffered prejudice attributable to the delay.”
`
`Personalized Media Commc'ns, LLC v. Apple Inc., 57 F.4th 1346, 1354 (Fed. Cir. 2023).
`
`The doctrine should be “sparingly” applied only to “egregious cases of misuse of the
`
` 
`
`8
`
`

`

`Case 1:17-cv-00770-JDW Document 448 Filed 08/21/24 Page 9 of 21 PageID #: 40708
`
`statutory patent system.” Symbol Techs., Inc. v. Lemelson Med., Educ. & Rsch. Found.,
`
`422 F.3d 1378, 1385 (Fed. Cir. 2005).
`
`28.
`
`Though “[t]he Federal Circuit has not expressly clarified an accused
`
`infringer's burden of proof for prosecution laches[,]” I follow other courts that have
`
`applied the clear and convincing evidence standard. Sonos, Inc. v. Google LLC, No. C 20-
`
`06754 WHA, 2023 WL 6542320, at *16 (N.D. Cal. Oct. 6, 2023). This standard is consistent
`
`with the presumption of validity and with the application of the clear and convincing
`
`evidence standard to other unenforceability defenses. See Natera, Inc. v. ArcherDX, Inc.,
`
`690 F. Supp. 3d 437, 445 (D. Del. 2023) (collecting cases).
`
`29.
`
`The prosecution history for the ‘530 Patent does not demonstrate
`
`unreasonable delay. Caterpillar counts the time from the initial application for the
`
`original ‘592 Patent to when the ‘530 Patent issued. Eight years elapsed before Wirtgen
`
`dropped the individually-adjustable-leg requirement. Even if I discount this delay by the
`
`Patent Term Adjustments for the ‘530 Patent family, there remains a five-year delay.3 But
`
`“prosecution laches is not simply a time-counting exercise.” Seagen Inc. v. Daiichi
`
`Sankyo Co., No. 2:20-CV-00337-JRG, 2022 WL 2789901, at *7 (E.D. Tex. July 15, 2022).
`
`Wirtgen’s conduct also matters.
`
` 
`3 When an applicant himself creates delays, he cannot later blame the PTO. See
`Personalized Media Commc'ns, LLC, 57 F.4th at 1355. But here I find no evidence that
`Wirtgen intentionally created prosecution delays for which it is trying to shift the blame.
`Thus, I can discount the eight-year delay that Caterpillar cites.
` 
`
` 
`
`9
`
`

`

`Case 1:17-cv-00770-JDW Document 448 Filed 08/21/24 Page 10 of 21 PageID #: 40709
`
`30.
`
`There’s no evidence to suggest that Wirtgen “employed an inequitable
`
`scheme to extent its patent rights.” Personalized Media Commc'ns, LLC, 57 F.4th 1350.
`
`Wirtgen’s actions differ in material ways from situations where courts have applied
`
`prosecution laches. For example, Caterpillar does not offer evidence or argue that
`
`Wirtgen requested or received unusual extensions during prosecution of the ‘530
`
`Patent. See Natera, Inc., 690 F. Supp. 3d at 446 (inequitable conduct may include filing
`
`hundreds of applications, receiving extensions and unreasonably increasing the number
`
`of claims). It also does not argue that there are “unexplained gaps” in the prosecution
`
`history. See id. at 447 (quoting Seagen Inc., 2022 WL 2789901, at *6). Caterpillar cites an
`
`eight-year delay, but “[d]uration of prosecution … does not provide a bright-line rule as
`
`to the reasonableness of prosecution.” Cordance Corp. v. Amazon.com, 631 F. Supp. 2d
`
`484, 491 (D. Del. 2009).
`
`31. What Caterpillar cites as inequitable is Wirtgen’s last-minute broadening
`
`of the claims to reach Caterpillar’s machines. There is a close temporal connection
`
`between Wirtgen’s acquisition and study of the Caterpillar machines and its amendment
`
`of the claim. I infer that those machines motivated Wirtgen to broaden its claim. But,
`
`even so, “there is nothing improper, illegal or inequitable in filing a patent application
`
`for the purpose of obtaining a right to exclude a known competitor's product from the
`
`market; nor is it in any manner improper to amend or insert claims intended to cover a
`
`competitor's product the applicant's attorney has learned about during the prosecution
`
` 
`
`10
`
`

`

`Case 1:17-cv-00770-JDW Document 448 Filed 08/21/24 Page 11 of 21 PageID #: 40710
`
`of a patent application.” Kingsdown Med. Consultants, Ltd. v. Hollister Inc., 863 F.2d 867,
`
`874 (Fed. Cir. 1988).
`
`32.
`
`As a result, even a finding that a party “drafted patent claims to cover [its
`
`competitor’s] products … [does] not by itself require a finding of prosecution laches.”
`
`SynQor, Inc. v. Artesyn Techs., Inc., No. 2:07-CV-497-TJW-CE, 2011 WL 2729214, at *7
`
`(E.D. Tex. July 13, 2011); see also Ormco Corp. v. Align Tech., Inc., 647 F. Supp.2d 1200,
`
`1207 (C.D. Cal. 2009). By amending its patent in this manner, Wirtgen did not engage in
`
`an egregious “misuse” of the patent system. SynQor, Inc., 2011 WL 2729214, at *7.
`
`33.
`
` Absent unfair conduct, courts routinely decline to apply prosecution
`
`laches when evaluating delays of this length or longer. See Natera, Inc., 690 F. Supp.3d
`
`at 447 (collecting cases with seven-, eight-, ten-, and fourteen-year delays).
`
`34.
`
`Caterpillar cites to Hyatt for the proposition that a six-year delay is
`
`presumptively unreasonable. See Hyatt, 998 F.3d at 1370. But the Federal Circuit was
`
`ruling both in a different context (whether laches is an available defense to the PTO in
`
`an action to obtain a patent under § 145) and on a different issue (the delay between
`
`learning of infringement and filing suit). See id. As a result, some courts have been
`
`skeptical to extend this presumption to a prosecution laches defense. See Personalized
`
`Media Commc'ns, LLC v. Apple, Inc., 552 F. Supp. 3d 664, 685 (E.D. Tex. 2021), aff'd, 57
`
`F.4th 1346 (Fed. Cir. 2023); Sonos, Inc., 2023 WL 6542320, at *16 n.7. Caterpillar hasn’t
`
` 
`
`11
`
`

`

`Case 1:17-cv-00770-JDW Document 448 Filed 08/21/24 Page 12 of 21 PageID #: 40711
`
`convinced me that I must apply the Hyatt presumption in this context, and I decline to
`
`do so.
`
`35.
`
`Caterpillar has presented evidence that raises some questions about
`
`Wirtgen’s conduct. But there’s not enough evidence to satisfy the clear and convincing
`
`evidence standard. Because the first element of the test is not satisfied, I don’t have to
`
`address the second element.
`
`III.
`
`‘788 PATENT
`
`A.
`
`36.
`
`Findings Of Fact
`
`The ‘788 Patent relates to a road construction machine with a leveling
`
`device to produce an even milled surface. It claims a machine with a sensor switching
`
`that doesn’t interrupt the milling process. The invention allows that “[a]t the time of
`
`switchover, the sensor can … be changed without any alteration of the currently
`
`applicable adjustment value.” (‘788 Patent at 2:4-7.)
`
`37.
`
`Claim 1 of the ‘788 Patent recites:
`
`A road construction machine for the treatment of road surfaces,
`comprising:
`
`a milling drum, the milling drum being height adjustable with regard to
`milling depth and/or slope; and
`
`a leveling system operable to control the milling depth and/or the slope
`of the milling drum, the leveling system including:
`
`a plurality of selectable sensors for sensing current actual values of
`operating parameters including the milling depth and/or the slope of
`the milling drum relative to a reference surface;
`
`12
`
`
`
`
`
`
`
` 
`
`

`

`Case 1:17-cv-00770-JDW Document 448 Filed 08/21/24 Page 13 of 21 PageID #: 40712
`
` a
`
` plurality of indication and setting devices, each of the indication and
`setting devices being associatable with at least one of the plurality of
`selectable sensors, each indication and setting device being operable to
`indicate the current actual value of and to set a set value for the
`operating parameter sensed by its associated sensor;
`
` a
`
` controller operable to control the milling depth and/or the slope of
`the milling drum conditioned on set values and sensed current actual
`values of the operating parameters sensed by a selected subset of the
`plurality of selectable sensors by returning at least one adjustment value
`to adjust the milling depth and/or slope of the milling drum so that the
`sensed current actual values of the operating parameters approach the
`set values for the selected subset of the plurality of selectable sensors;
`
`a switchover device operable to switch over from control based upon a
`first selected subset of the plurality of selectable sensors to control
`based upon a second selected subset, the second selected subset
`exchanging at least one replacement sensor not in the first subset for at
`least one replaced sensor that was in the first subset; and
`
`the controller being operable to effect switchover from control based
`upon the first selected subset of selectable sensors to control based
`upon the second selected subset of selectable sensors during milling
`operation without interruption of the milling operation and without any
`erratic alteration of the at least one adjustment value for adjusting the
`milling depth and/or slope of the milling drum.
`
`(‘788 Patent at 7:2-45.)
`
`38.
`
`Claim 5 of the ‘788 Patent depends on Claim 1. (‘788 Patent at 7:64.)
`
`39.
`
`Claim 5 of the ‘788 Patent recites:
`
`The road construction machine of claim 1, wherein: the switchover
`device and the one of the indication and setting devices associated with
`the replacement sensor are operable to pre-select the replacement
`sensor and to pre-set the operating parameter of the replacement
`sensor prior to effecting the switchover.
`
`13
`
`
`
` 
`
`

`

`Case 1:17-cv-00770-JDW Document 448 Filed 08/21/24 Page 14 of 21 PageID #: 40713
`
`(‘788 Patent at 7:64-8:2.)
`
`40.
`
`U.S. Patent No. 8,308,395 is a continuation of the ‘788 Patent. (D.I. 367 ¶ 5
`
`n.7.) A continuation patent application is “an application filed subsequently to another
`
`application, while the prior application is pending, disclosing all or a substantial part of
`
`the subject matter of the prior application and containing claims to subject-matter
`
`common to both applications, both applications being filed by the same inventor or his
`
`legal representative.” U.S. Water Servs., Inc. v. Novozymes A/S, 843 F.3d 1345, 1348 n.1
`
`(Fed. Cir. 2016) (internal quotation marks and citation omitted).
`
`41.
`
`The ‘395 Patent also relates to a sensor-switching device for a road
`
`construction machine. The specification teaches that “[a]ll embodiments indicate the set
`
`values and actual values of the pre-selected sensor [] which is to be exchanged for a
`
`previously used sensor …” (‘395 Patent at 6:45-47.) “It is possible in this way to pre-set
`
`all setting values (set values and actual values of the pre-selected sensor … prior to
`
`entering a switchover command.” (Id. at 6:48-52.)
`
`42.
`
`The invention disclosed in Claim 1 of the ‘395 Patent is a road construction
`
`machine with the capability of selecting a replacement sensor and setting an operating
`
`parameter.
`
`43.
`
`Claim 1 of the ‘395 Patent recites:
`
`A road construction machine for the treatment of road surfaces,
`comprising:
`
`
` 
`
`14
`
`

`

`Case 1:17-cv-00770-JDW Document 448 Filed 08/21/24 Page 15 of 21 PageID #: 40714
`
`a milling drum, the milling drum being position adjustable with regard
`to at least one position characteristic selected from the group consisting
`of milling depth of the drum and slope of the drum; and
`
` a
`
` leveling system configured to control the at least one position
`characteristic, the leveling system including:
`
` a
`
` plurality of selectable sensors, each sensor configured to sense a
`current actual value of an operating parameter corresponding to at least
`one of the milling depth of the drum and the slope of the drum;
`
` a
`
` plurality of indication and setting devices, each of the indication and
`setting devices being associatable with at least one of the plurality of
`selectable sensors, each indication and setting device being operable to
`indicate the current actual value of and to set a set value for each
`operating parameter sensed by its associated sensor or sensors;
`
` a
`
` controller and switchover system configured to control the at least
`one position characteristic conditioned on set value or values and
`sensed current actual value or values of the operating parameter or
`parameters sensed by a selected subset of the plurality of selectable
`sensors by returning at least one adjustment value to adjust the at least
`one position characteristic so that the sensed current actual value or
`values of the operating parameter or parameters approach the set value
`or values for the selected subset of the plurality of selectable sensors;
`and
`
`the controller and switchover system being configured to switch over
`from control based upon a first selected subset of the plurality of
`selectable sensors to control based upon a second selected subset
`during milling operation without interruption of the milling operation
`and without any erratic alteration of the at least one adjustment value,
`the second selected subset exchanging at least one replacement sensor
`not in the first subset for at least one replaced sensor that was in the
`first subset.
`
`(‘395 Patent at 7:2-41.)
`
` 
`
`15
`
`

`

`Case 1:17-cv-00770-JDW Document 448 Filed 08/21/24 Page 16 of 21 PageID #: 40715
`
`44. On November 27, 2019, the PTAB issued a Final Written Decision
`
`invalidating Claim 1 of the ‘395 Patent as obvious. In that action, Caterpillar argued that
`
`Claim 1 of the ‘395 Patent was obvious in light of two prior art sources (Davis4 and
`
`Brabec5). (D.I. 369-23 at 20-21.) The PTAB invalidated Claim 1 of the ‘395 Patent because
`
`it “merely recite[d] a combination of well-known prior art elements that perform their
`
`known functions to produce predictable results.” (D.I. 369-23 at 8.) It held that a “POSITA
`
`would merely need to incorporate Brabec’s sensor swap functionality into Davis’s
`
`controller system to arrive at the claimed invention of the ‘395 patent.” (D.I. 369-23 at 25
`
`(emphasis removed).)
`
`45.
`
`The PTAB expressed no opinion as to when the invention disclosed in
`
`Claim 1 of the ‘395 Patent requires that the selection and setting occur.
`
`46.
`
`The PTAB’s decision did not discuss whether prior art disclosed a
`
`switchover device operable to preselect a replacement sensor and to pre-set a operating
`
`parameter prior to effecting a switchover.
`
`B.
`
`47.
`
`Conclusions Of Law
`
`Collateral estoppel precludes a party from contesting a matter that it had a
`
`full and fair opportunity to previously litigate. “When assessing the doctrine in a patent
`
`case, a district court must apply regional circuit law to the general procedural question
`
` 
`4 U.S. Patent Pub. No. 2002/0047301.
`5 U.S. Patent Pub. No. 2002/0154948.
`
` 
`
`16
`
`

`

`Case 1:17-cv-00770-JDW Document 448 Filed 08/21/24 Page 17 of 21 PageID #: 40716
`
`of whether collateral estoppel applies.” Kroy IP Holdings, LLC v. Groupon, Inc., No. CV
`
`17-1405-MN-CJB, 2022 WL 17403538, at *4 (D. Del. Dec. 2, 2022). Federal Circuit law
`
`controls when substantive issues of patent law arise. See Biogen Int'l GmbH v. Amneal
`
`Pharms. LLC, 487 F. Supp. 3d 254, 263 (D. Del. 2020) (citing Ohio Willow Wood Co. v.
`
`Alps S., LLC, 735 F.3d 1333, 1342 (Fed. Cir. 2013)).
`
`48.
`
`In the Third Circuit, collateral estoppel applies when: “(1) the identical issue
`
`was previously adjudicated; (2) the issue was actually litigated; (3) the previous
`
`determination was necessary to the decision; and (4) the party being precluded from
`
`relitigating the issue was fully represented in the prior action.” Jean Alexander
`
`Cosmetics, Inc. v. L'Oreal USA, Inc., 458 F.3d 244, 249 (3d Cir. 2006). Caterpillar, “as the
`
`party seeking … estoppel has the burden of demonstrating the propriety of its
`
`application.” Suppan v. Dadonna, 203 F.3d 228, 233 (3d Cir. 2000).
`
`49.
`
`Claim 1 of the ‘395 Patent (adjudicated) and Claim 5 of the ‘788 Patent
`
`(unadjudicated) are not identical, so there’s a question of whether the PTAB’s decision is
`
`the kind of decision that gets preclusive effect.
`
`50.
`
`Certainly, if the PTAB were to invalidate identical claims in the same
`
`litigation, preclusion would apply. See Papst Licensing GMBH & Co. KG v. Samsung
`
`Elecs. Am., Inc., 924 F.3d 1243, 1250 (Fed. Cir. 2019). The Federal Circuit has held that “a
`
`decision by a court invalidating one patent may collaterally estop the litigant from
`
`asserting the validity of materially similar, unadjudicated claims in litigation.” M2M Sols.
`
` 
`
`17
`
`

`

`Case 1:17-cv-00770-JDW Document 448 Filed 08/21/24 Page 18 of 21 PageID #: 40717
`
`LLC v. Sierra Wireless Am., Inc., No. CV 14-1102-RGA, 2020 WL 7767639, at *6 (D. Del.
`
`Dec. 4, 2020), report and recommendation adopted, No. 14-CV-01102-RGA, 2021 WL
`
`7441706 (D. Del. Mar. 31, 2021) (citing Ohio Willow Wood Co., 735 F.3d at 1342). But the
`
`Federal Circuit hasn’t gone as far as extending this holding when the PTAB is the
`
`decisionmaker. See id.
`
`51. Many courts have held that the PTAB’s invalidation of a substantially
`
`similar claim can’t be given preclusive effect. See, e.g., IOENGINE, LLC v. PayPal Holdings,
`
`Inc., 607 F. Supp. 3d 464, 489 (D. Del. 2022) (Bryson, J.) (collecting cases); but see
`
`Fellowes, Inc. v. Acco Brands Corp., No. 10 CV 7587, 2019 WL 1762910, at *6 (N.D. Ill.
`
`Apr. 22, 2019). I find those cases persuasive. The PTAB finds invalidation using a
`
`preponderance of the evidence standard. But in court, a party seeking to invalidate a
`
`patent must do so by clear and convincing evidence. See IOENGINE, LLC, 607 F. Supp.
`
`3d at 489. Collateral estoppel is inappropriate when “the burden of proof on an issue in
`
`the prior proceeding was less stringent than the burden of proof on the issue as to
`
`which preclusion is sought in the second proceeding.” Id. at 488. I conclude that
`
`collateral estoppel doesn’t apply to Wirtgen’s claim that Caterpillar infringed Claim 5 of
`
`the ‘788 Patent.
`
`52.
`
`This conclusion—that collateral estoppel does not apply based on
`
`differing burdens of proof—is not novel, nor is it limited to patent law. For example, an
`
`individual might obtain an acquittal in a criminal trial (where he only has to demonstrate
`
` 
`
`18
`
`

`

`Case 1:17-cv-00770-JDW Document 448 Filed 08/21/24 Page 19 of 21 PageID #: 40718
`
`reasonable doubt), but the government authorities remain free to assert actual guilt as a
`
`defense in a subsequent civil suit under section 1983 (where the same individual has to
`
`prevail on a preponderance of evidence standard). See Chisholm v. Def. Logistics
`
`Agency, 656 F.2d 42, 48 n.11 (3d Cir. 1981).
`
`53.
`
`Even if I were to hold that collateral estoppel could apply in theory, I
`
`would still find that Caterpillar hasn’t shown that Claim 1 of the ‘395 Patent and Claim 5
`
`of the ‘788 Patent are substantially similar.
`
`54.
`
`For the identity of the issues prong, in the context of invalidity, collateral
`
`estoppel is not limited to instances where claim terms are identical. See Ohio Willow
`
`Wood Co., 735 F.3d at 1342. Rather, when differences between unadjudicated patent
`
`claims and adjudicated ones “do not materially alter the question of invalidity[,]”
`
`collateral estoppel may apply. See id.; see also Google LLC v. Hammond Dev. Int'l, Inc.,
`
`54 F.4th 1377, 1381 (Fed. Cir. 2022). A court must therefore “determine whether the
`
`invalidated patent claims are ‘substantially similar’ to the unadjudicated patent claims.”
`
`TQ Delta, LLC v. 2Wire, Inc., No. CV 13-1835-RGA, 2021 WL 2671296, at *5 (D. Del. June
`
`29, 2021) (quoting Ohio Willow Wood Co., 735 F.3d at 1342).
`
`55.
`
`The Parties dispute whether Caterpillar has met the first requirement for
`
`collateral estoppel: identical issues in both cases. The PTAB invalidated Claim 1 of the
`
`‘395 Patent. To Caterpillar, this estops Wirtgen from now asserting Claim 5 of the ‘788
`
`Patent. To reach that conclusion, Caterpillar argues that Claim 1 of the ‘395 Patent is
`
` 
`
`19
`
`

`

`Case 1:17-cv-00770-JDW Document 448 Filed 08/21/24 Page 20 of 21 PageID #: 40719
`
`substantially similar to Claim 1 of the ‘788 Patent. In turn, Claim 1 of the ‘788 Patent is
`
`substantially similar to Claim 5 of that patent. So, stringing it all together, Claim 1 of the
`
`‘395 Patent is sufficiently similar to Claim 5 of the ‘788 Patent.
`
`56