When What You Plead Comes Back to Bite You
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By Alexandros Nikolaidis | USPTO Reg. No. 84,755 | Niki IP Services
Patent law has a long memory. A theory broad enough to win infringement may also be broad enough to prove invalidity, defeat standing, or turn the patentee’s own specification into the other side’s roadmap. These cases are funny because the courts often do not reject the argument - they accept it, and that is the problem.
Patent lawyers are trained to think in doctrinal boxes: infringement, validity, ownership, standing, prosecution history, priority, damages, and remedies. Patent law, however, has a mischievous habit of walking out of one box and setting up camp in another.
A factual theory broad enough to capture the accused product may also be broad enough to capture the prior art. A claim-construction position broad enough to avoid noninfringement may also be broad enough to destroy enablement. An ownership theory useful before the Patent Office may become fatal in court. And sometimes, the plaintiff’s own story supplies the missing fact that defeats the case.
That is the recurring lesson of a surprisingly entertaining line of patent cases: what you plead can come back to bite you.
The best examples are not merely cases where patentees made bad arguments and lost. They are cases where courts accepted the patentee’s premise and then followed it to its logical, usually brutal, conclusion. In other words: assume you are right. That is precisely why you lose.
The newest example may be one of the cleanest. In Nesarikar v. United States Patent and Trademark Office, the applicants sought micro-entity status under 35 U.S.C. § 123. The difficulty was that micro-entity status is limited, in part, by the number of earlier applications on which the applicant has been named as an inventor. Section 123(b), however, excludes certain applications if the applicant has assigned, or is under an obligation by contract or law to assign, all ownership rights as a result of previous employment.
That created an obvious temptation. The applicants argued to the USPTO that earlier applications should not count against them because they were obligated to assign them. They also represented that they were obligated to assign the application at issue. But they did not provide the actual assignment language, identify the operative terms, or show when the obligation arose and to whom it ran.
When the application was later treated as abandoned and the applicants sued the USPTO, that same assignment-obligation theory became a standing problem. If they were obligated to assign the application, what legally protected ownership interest did they personally have in challenging the USPTO’s treatment of it?
The Federal Circuit did not hold that an obligation to assign always destroys standing. It did something more useful: it required specificity. The applicants had set themselves the task of pleading enough assignment obligation to preserve the micro-entity theory without pleading themselves out of a concrete interest in the application. Conclusory ownership assertions were not enough. Proof of an actual assignment was not necessarily required; proof of the duty to assign might have been enough.
The case is a useful reminder of the inventor-first baseline recognized in Stanford v. Roche: inventions initially belong to inventors unless a valid agreement later changes that result. But Nesarikar shows the other side of the same rule. If the applicant invokes an agreement or legal duty contrary to inventor ownership, the applicant may have to live with the ownership consequences of that theory.
The lesson is simple: a duty to assign is not a magic phrase. If it matters, the litigant must explain the terms, assignee, timing, and legal effect. Otherwise, a representation made to obtain one procedural benefit may become the fact that defeats standing.
I Forgot I Assigned My Own Patent”: Lans v. Digital Equipment
If Nesarikar is the modern micro-entity version of the ownership trap, Lans v. Digital Equipment is the classic standing self-own.
Håkan Lans, a Swedish inventor, sued major computer companies for infringement of a patent on a color computer graphics system. The case was brought in his own name. Discovery revealed a rather inconvenient fact: years earlier, Lans had assigned the patent to his own company, Uniboard Aktiebolag, for tax and licensing purposes.
The result was fatal. Lans was the inventor, but he was not the patent owner when he filed suit. The Federal Circuit affirmed dismissal because standing must exist at the start of the case. The court also affirmed the refusal to substitute Uniboard after the fact. A plaintiff cannot file first and fix ownership later.
The case is almost too neat. Lans had arranged ownership one way for tax or business reasons, then litigated as though ownership were arranged another way for enforcement purposes. The corporate form did not disappear when it became inconvenient.
The punchline is harsh but practical: patent ownership is not an adjustable costume. It does not switch from inventor to company and back again depending on which venue has the better lighting. It is the cornerstone of the right to sue.
Evans Cooling Systems v. General Motors adds a different kind of bite. Evans alleged that GM’s LT1 Corvette engine cooling system infringed its patent. GM responded with the on-sale bar: if the LT1 system practiced the claimed invention, then pre-critical-date Corvette orders placed the invention on sale before the patent application was filed.
Evans’s infringement theory helped GM prove embodiment. GM still had to show a qualifying commercial offer or sale, but Evans’s own allegation supplied the link between the accused LT1 system and the claimed invention. In effect, Evans said, “GM sold cars containing my invention.” GM answered, “Yes, and according to you, they sold them too early for your patent to survive.”
Evans also argued that GM should not be permitted to use its own alleged misappropriation as invalidating prior activity. The Federal Circuit declined to create such an exception. The on-sale bar turned on the statutory consequences of the sale, not on the patentee’s preferred theft narrative.
The comic version is irresistible: “You stole my invention!” “Maybe, but your complaint says we stole it before your critical date.”
The practical point is equally serious. File before commercializing, pitching, demonstrating, or otherwise exposing the invention in a way that can later be characterized as a sale or offer for sale. NDAs, handshakes, and oral understandings are poor substitutes for a timely patent filing. Disputes such as Ethox Chemical LLC v. Coca-Cola Co. show how expensive and fact-intensive invention-disclosure disputes can become even when the trade-secret theory survives past the pleadings.
EscapeX v. Google is the software-age cousin of Evans Cooling. EscapeX accused Google’s YouTube-related Auto-Add functionality of infringing its patent. Google warned that the accused feature predated the patent’s priority date. That created the obvious problem: if the feature practiced the claims, then it was not merely infringing - it was anticipatory.
The Federal Circuit affirmed an attorney-fee award after the district court found the case frivolous. The point was not difficult patent metaphysics. It was ordinary litigation logic. A plaintiff cannot build infringement around a feature that predates the patent without confronting the validity consequences of that same feature.
EscapeX belongs in the same family as Evans because both involve a plaintiff’s infringement theory becoming the invalidity theory. The accused product history does not begin on the filing date of the patent. If the feature existed early enough, a broad infringement read may become a prior-art read.
SmithKline Beecham v. Apotex is a pharmaceutical version of the same trap. The patent covered paroxetine hydrochloride hemihydrate. Apotex’s product used paroxetine hydrochloride anhydrate. SmithKline’s infringement theory relied on conversion: in a seeded, humid environment, at least some anhydrate would convert into hemihydrate. Thus, SmithKline argued, Apotex’s anhydrate product would necessarily contain the patented hemihydrate.
The Federal Circuit accepted the critical factual premise about conversion. But that acceptance came with consequences. If prior-art anhydrate necessarily converted to hemihydrate under ordinary conditions, then the claimed hemihydrate was inherently present in the prior art. The infringement theory became an inherent-anticipation theory.
This is the pharmaceutical self-own in its purest form. A factual mechanism cannot be inevitable for infringement but irrelevant for anticipation. Chemistry, unlike litigants, does not usually agree to change theories mid-brief.
The broader and more nuanced the theory needed to catch the defendant, the more carefully it must be tested against the prior art.
Liebel-Flarsheim v. Medrad is one of the most famous “be careful what you ask for” cases in patent law.
Liebel sued Medrad over powered fluid injectors. Medrad’s accused device did not use a pressure jacket. To prove infringement, Liebel pushed for a claim construction that did not require a pressure jacket. The Federal Circuit agreed with the broad construction.
But that victory created a § 112 problem. Once the claims were broad enough to cover jacketless injectors, the specification had to enable jacketless injectors. It did not. The record showed that the disclosed systems used pressure jackets, that jacketless prototypes had not been made or described at filing, and that jacketless operation was not a simple design choice. Worse, the specification effectively taught away from the jacketless system Liebel needed for infringement.
The irony was unmistakable: Liebel won the claim-construction battle and then had to prove enablement across the very breadth it had demanded. It could not.
The rule is not anti-broad-claims. It is anti-unsupported-breadth. A patentee may claim broadly, but broad claims require broad enablement. The safer drafting lesson is to include fallback dependent claims that track the actual embodiments and examples in the specification. If the broad theory fails, the patentee may still be left with something enforceable.
Sitrick v. DreamWorks follows the same structure. The patents involved substituting or integrating user images or voices into preexisting media. The patentee resisted limiting the claims to video games and asserted them against movie technology.
The court accepted the broader reach for claim-scope purposes, but that meant the claims had to be enabled for both video games and movies. The specification did not enable the movie embodiments. The Federal Circuit affirmed invalidity for lack of enablement. Critically, where a critical component should have appeared in the specification for how to practice the invention in movies, the disclosure had essentially left a blank box.
The self-own is structurally identical to Liebel. The patentee said, “The claims are broad enough to reach the defendant’s technology.” The court responded, in substance, “Fine, but do not expect us to fill in the blanks.” You cannot leave a key interface as a blank box and expect the court - or the accused infringer - to complete the engineering later.
MagSil v. Hitachi adds another version of the same problem. The claim used open-ended language requiring a resistance change of “at least 10%.” The patentee sought a construction that allowed the claim to cover later-developed products with much larger resistance changes.
The Federal Circuit treated “at least 10%” as open-ended. That made the claim broad enough to cover dramatic later improvements - in practical terms, up to no upper limit - but it also required enablement of that full open-ended scope. The specification disclosed far less. The claim failed.
The memorable lesson is that open-ended language does not give the patentee free future inventions. “At least” can be a powerful phrase, but it also creates an enablement burden, especially for claims where there is no natural 100% ceiling. If the claim reaches from 10% to the horizon, the specification must justify the trip.
Admissions in the Specification: The Quiet Self-Own
Admissions in the Specification: The Quiet Self-Own
Not every self-defeating patent theory appears first in litigation. Some are planted years earlier in the specification, quietly waiting like little doctrinal landmines.
Patent applicants often write background sections as though they are harmless tutorials. They are not. Statements that something was “well known,” “conventional,” “routine,” or “within the skill of the art” may later be treated as applicant-admitted prior art, motivation-to-combine evidence, or proof that a missing feature was readily available.
This does not mean applicants should hide the ball or under-enable their inventions. It means they should be careful about unnecessary admissions. There is a difference between enabling the invention with concrete examples and broadly announcing that a person of ordinary skill could easily supply the missing pieces.
PharmaStem Therapeutics v. ViaCell is a useful warning. The patents involved stem cells in umbilical cord blood. The Federal Circuit relied in part on admissions in the specification and prior-art teachings to reject the patentee’s attempt to characterize the invention as nonobvious. The court viewed the inventors as having used routine methods to confirm what the art already believed.
When the patentee objected, the court pointed back to the specification itself: the patent had described every single step of the invention as known in the art.
That is the quiet self-own: the background section intended to tell the invention’s story can become the defendant’s roadmap for obviousness.
There are limits. Riverwood is an important caution against overstating the doctrine. Not every IDS citation is an admission, and a patentee is not necessarily punished for being inclusive with disclosures. But the drafting lesson remains: do not casually say “everyone knew X” or “anyone could easily do Y” unless you are prepared to live with that sentence later.
Better practice is usually to disclose concrete embodiments rather than unnecessary field-wide concessions. Instead of saying a POSITA could readily implement an entire missing system, give an example implementation. Enable the invention without writing the invalidity argument for the other side.
Another recurring self-own arises when a patentee wants the claim to mean one thing for infringement and another thing for validity.
In CommScope v. Dali Wireless, the Federal Circuit rejected an attempt to use inconsistent claim interpretations. You cannot say one claim construction is “unchallenged” to escape invalidity and then call it “nonsense” to establish infringement. The claim is not a nose of wax.
This is one of the simplest article themes because the logic is intuitive. If the same claim language reads on the accused product under a particular theory, then the patentee must confront whether that same theory reads on the prior art. Alternative pleading has its place. A claim that changes shape depending on whether the patentee is discussing infringement or validity does not.
“This Invention” Means This Invention: Honeywell and SciMed
“This Invention” Means This Invention: Honeywell and SciMed
Some litigants are bitten not by what they plead in court, but by what they said in the patent itself.
In Honeywell v. ITT, the patentee argued for a broad reading of “fuel injection system component.” But the specification repeatedly described “this invention” or “the present invention” as the fuel filter. The Federal Circuit limited the claim accordingly.
SciMed v. Advanced Cardiovascular Systems is another classic. The patentee wanted catheter claims broad enough to cover a side-by-side lumen arrangement, but the specification had described the coaxial arrangement as part of the invention and criticized alternative arrangements. The court treated that language as a disclaimer.
These cases teach a different version of the same lesson: the specification is not a technology news article. Phrases like “the present invention,” “all embodiments,” or broad disparagement of alternatives can become claim-scope handcuffs.
The irony is that applicants often use those phrases to make the patent sound clearer and more important. Years later, the same clarity may become the reason the claim cannot reach the defendant.
Chef America is less about pleading and more about claim drafting, but it belongs in the article because it is too good to omit.
The claim required heating dough to a temperature in the range of 400 to 850 degrees Fahrenheit. The patentee argued that this obviously meant placing the dough in an oven at that temperature, not literally heating the dough itself to that temperature.
The Federal Circuit refused to rewrite the claim. The patentees had a chance to amend the claim and switch the “heating to” language to “heating at” language. They did not. If the claim said heat the dough to 400 to 850 degrees, that is what it meant - even if the result would be culinary disaster. The claim language, not the desired end result, controls.
The lesson is wonderfully harsh: courts construe claims; they do not rescue them. Sometimes what comes back to bite you is not a litigation theory, but the sentence you wish you had drafted differently.
A good article on self-defeating patent facts should close with history. Long before modern Federal Circuit doctrine, Egbert v. Lippmann offered a nineteenth-century version of the same irony.
The invention was an improved corset spring. The inventor gave the springs to a woman who used them for years. The use was not publicly visible in the ordinary sense; it occurred inside a corset. But the Supreme Court held that the use could still be a public use because it was unrestricted, nonexperimental, and ordinary.
Justice Miller’s dissent captured the absurdity: while the statute defeats a patent only by a public use, the majority’s logic also made it fatal when the article, by its nature, could never be publicly seen during ordinary use.
That makes Egbert a perfect historical closing example. The patentee’s story was not that the invention had been commercially exploited on a public stage. The story was that it had been privately used in a way that, by its nature, could not be publicly observed. But the lack of secrecy restrictions made the private use legally public.
From corset springs to color graphics patents, the lesson has not changed: facts do not always stay in the doctrinal box the litigant intended.
The Unifying Principle
The Unifying Principle
These cases are easy to laugh at because the self-owns are so clean. But they are not merely anecdotes. They reflect a structural feature of patent law: patent doctrines are interlocked.
· Infringement scope affects validity.
· Claim construction affects enablement and written description.
· Prosecution statements affect enforcement.
· Ownership documents affect standing.
· Specification admissions affect obviousness.
· Commercial timelines affect patentability bars.
· Factual theories about what the accused product does may also prove what the prior art did.
That is why the safest patent theory is not always the broadest one. Sometimes the theory that wins the immediate fight creates the harder fight next.
The practical takeaway is not timidity. Patent owners should still enforce valid patents, argue for fair claim scope, and explain their inventions clearly. But before making a broad assertion, counsel should ask the next question: if the court accepts this as true, what else follows?
If the answer is “the patent is invalid,” “the plaintiff lacks standing,” “the prior art anticipates,” or “the specification does not enable the claim,” then the argument may be less a sword than a boomerang with a very accurate return path.
Practice Pointers
Practice Pointers
1. Check ownership before filing. Inventorship is not ownership, and assignment history is not clerical housekeeping. If the patent was assigned to a company, trust, university, or affiliate, the plaintiff must be the correct rights holder at the start of the case.
2. Test infringement theories against the prior art. A read broad enough to capture the accused product must be checked against every pre-critical-date product, publication, and sale.
3. Treat claim construction as a validity decision too. A broader construction may win infringement but lose enablement, written description, anticipation, or obviousness.
4. Draft specifications without unnecessary admissions. Enable with examples, not sweeping concessions. Avoid casually declaring what was conventional, routine, obvious to implement, or known to everyone unless that statement is necessary and strategically safe.
5. Avoid “present invention” language unless the limitation truly defines every claim. The easiest way to lose claim breadth is to describe the invention more narrowly than the claims. “In a particular implementation of the invention” is usually safer.
6. Preserve consistency. The same claim language cannot mean one thing when pointed at the defendant and another when pointed at the prior art.
Conclusion
Conclusion
The most satisfying patent self-own cases are not the ones where courts reject a party’s argument. They are the ones where courts accept it.
Yes, your claim is broad enough to cover the jacketless injector. Now show that you enabled jacketless injectors the specification effectively discouraged.
Yes, the anhydrate converts to hemihydrate. Now explain why prior-art anhydrate left in ordinary conditions did not inherently do the same thing.
Yes, the Corvette cooling system embodied your invention. Now explain why the pre-critical-date Corvette order was not an on-sale bar.
Yes, you were obligated to assign the application. Now explain why you personally have standing.
Yes, you are the inventor. But did you still own the patent when you sued?
Patent law has a long memory and a habit of connecting doctrines that litigants would prefer to keep separate. The best advocacy anticipates those connections before the other side turns them into a punchline.
The title practically writes itself: when what you plead comes back to bite you.
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