Laches and Equitable Estoppel

Troxler Electronic Labs v. Pine Instrument (E.D.N.C. October 6, 2008).

In 2001, Troxler filed a patent infringement action against Pine – alleging infringement of its patent covering equipment for testing the quality of asphalt. In 2002, Pine counterclaimed with its own infringement allegations against Troxler. The two companies were direct competitors in this market and together held most of the market share.

The dates are important here:

  • 1996: In a letter, Pine accused Troxler of infringement (pre-issuance).
  • 1997: Pine’s patent Issues; In a letter, Troxler opined that Pine’s patent was invalid.
  • 2001: Troxler sues Pine on another patent
  • 2002: Pine counterclaims alleging infringement

In the 1996-2002 interim, it was clear that “Pine had first-hand knowledge that Troxler continued to sell its gyratory compactors. . . Despite this knowledge of Troxler’s allegedly infringing activities, Pine did not takeany action against Troxler to defend its patent until February 19, 2002, when it asserted its counterclaim. Nearly five years of allegedly infringing activity occurred before Pine took any legal action to defend its patent.” According to deposition testimony, Pine’s president explained the delay because he “didn’t feel motivated to pursue [the claim].”

Laches & Equitable Estoppel: Looking at these facts, Magistrate Judge Webb found that Pine may well be barred from pursuing its infringement allegations under the doctrines of equitable estoppels and laches.

Under the defense of equitable estoppel, the accused must have relied on the patentee’s assurances or non-enforcement activity in choosing to continue infringing. On summary judgment, the Magistrate recommended that the case go to trial to determine reliance:

[T]here is a material issue of fact as to whether Troxler was in fact lulled by Pine into a sense of security. Because of this material issue of fact, neither party is entitled to summary judgment on this prong Troxler’s equitable estoppel defense.

Enforcement Laches does not require detrimental reliance. However, the patentee must be shown to have “unreasonably and inexcusably” delayed bringing suit and that the alleged infringer subsequently suffered material prejudice. A six year delay creates a presumption of laches. Here, the delay was only five years – calculated from the 1997 patent issuance to the 2002 counterclaims. Although no presumption exists in this case, the magistrate judge noted that Pine’s excuse – lack of motivation – is insufficient.

[A] laches defense exists precisely to prevent patentees from delaying in filing suit simply because they do not feel “motivated to do so.” Accordingly, the undersigned hereby finds that Pine’s unjustified five year delay was unreasonable and that Troxler is entitled to summary judgment on the unreasonable delay prong of its laches defense

The harm of the delay can be shown in a variety of ways. Here, the magistrate judge focused on evidentiary harms and economic harms.

  • Evidence Lost: Troxler founder and CEO died during the interim. He had directed the development of the accused product.
  • Evidence Lost: Time delay has probably faded the memory of the Pine inventors.
  • Evidence Lost: Many documents have been destroyed. (Troxler is a family business – “When the drawer gets full, you toss something.”)
  • Economic: In the interim, Troxler has invested millions of dollars in manufacturing facilities and producing the alleged product.

Based on the potential validity of some of these arguments, the magistrate judge recommended they be explored at trial.

Unclean Hands: Because laches and equitable estoppel are both judged in equity, Pine argued that Troxler’s “unclean hands” should bar the company from relying upon those defenses. Particularly, Pine noted discovery shenanigans and filing suit without a good faith basis. The magistrate judge agreed that allegations of “egregious behavior” must be included in any equitable decision.

The district court will now decide whether to convert the magistrate judge’s recommendations into an order.

8 thoughts on “Laches and Equitable Estoppel

  1. 7

    I have been getting mineral rights on land owned by my mother and sold to me in 1971. Half of the land was my half siblings and they failed to file the deed with the county until this year. 1971 to 2008. they are suing the oil and gas co and me. The gas company couldnt find anything when they researched the leases and sales and since no deed had ever been filed by half siblings. Since I never was involved in the transfer of half the land fron my mother, I never knew any details. Without ever been filed, no details were ever public re cord. We are answering the suit by saying ,, frauds, statutes of limitations, waiver, laches and estoppel.. any advice.

  2. 6

    Here’s an issue that the CAFC should review on laches/equitable estoppel: whether asserting laches/EE requires turning over non-infringement and/or invalidity opinions.

    We tried arguing laches/EE in a California court. The judge ruled that, were we to do so, we had to turn over our non-infringement and invalidity opinions, as they would be relevant on whether we relied on the patentee’s delay. We thought that was an unfair call…

  3. 5


    (a) might work as an excuse against laches/estoppel (delay because of other litigation has been held to be a valid excuse), but (b) (pleading “poverty” isn’t an excuse) and (c) (many of the cases where laches/estoppel come up are because of protacted negotiations that peter out) likely won’t work.

  4. 4

    What if the owner of an infringed patent is
    (a) busy trying to get the infringer criminally prosecuted for crimes surrounding the infringement, and is incapable of pursuing infringement in parallel,
    (b) does not have the resources to bring an infringement suit against the infringer other than in a contingency arrangement, and
    (c) feels that “suing and settling” as potential patent counsel wants to out of the desire to “make a quick buck” is ethically unacceptable to the owner of the infringed patent, in view of the criminal aspects surrounding the case.

    Would a delay be held against the owner of the infringed patent???

  5. 3

    Probably should be barred from asserting the counterclaim. But it’s interesting that as a result, Pine is being punished for being non-litigious. Pine didn’t feel like being confrontational about it so Pine didn’t do anything… Troxler decided to be litigious and now Pine can’t fire back. kind of a perverse outcome

  6. 2

    Probably should be barred from asserting the counterclaim. But it’s interesting that as a result, Pine is being punished for being non-litigious. Pine didn’t feel like being confrontational about it so Pine didn’t do anything… Troxler decided to be litigious and now Pine can’t fire back. kind of a perverse outcome

  7. 1

    The patentee here is definitely in danger of being barred by an estoppel defense, as the magistrate has already ruled in Troxel’s favor on the first prong (misleading conduct), and now needs only to prove (by evidence) the second prong (detrimental reliance) and the third prong (material prejudice) which may not be difficult based on circumstances already known. Laches is going to be a tougher proposition as there is no “6-year” or “Aukerman” presumption here (first prong for laches) according to the magistrate; the second prong for laches (material prejudice) will depend on the same proof of the third prong for estoppel.

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