Admitted Prior art in 1886

Field v. De Comeau, 116 U.S. 187 (1886)

Field’s patent uses a spring to make it easier to slip on tight-fitting gloves.  The case reached the Supreme Court in 1886, but the court sided with the accused infringer.  The case involved admitted-prior-art.  In particular, the patent specification admitted “that springs had been combined before with the wrists of gloves” in the past. That admission assured the court that the patent cannot cover “the combination of springs in every form with the wrists of gloves to close them.”  The accused infringer was also using a spring-glove combination, but a different form than that claimed. As such, no infringement.

In this case, the court primarily used the admitted-prior-art to limit the scope of the patent in the infringement context, after recognizing that a broader interpretation would render the patent invalid.  That approach is common of the era.  Today, courts rarely rely upon the prior art when interpreting claim scope.  Still, admitted prior art would seemingly be quite relevant as part of the intrinsic analysis of claim scope.



32 thoughts on “Admitted Prior art in 1886

  1. 4

    Another good example of why one cannot safely rely on very old Sup. Ct. patent cases. The Fed. Cir. does not approve of judicially rewriting claims just to save them from prior art that could have been distinguished within the claims themselves, pre or post grant. [Although clear admissions in the prosecution history of what the claims are not intended to cover may still have some such effect in the U.S..]
    While spec “backgrounds” have indeed become more circumspect, known material prior art still has to be disclosed in some other acceptable way before grant to avoid the risk of an inequitable conduct defense.

    1. 4.1

      known material prior art still has to be disclosed in some other acceptable way before grant to avoid the risk of an inequitable conduct defense.

      You mean, besides the (dump truck potential) availability of the IDS system?

      Like 37 CFR 1.97 (especially (g) and (h):

      link to

      In other ‘news,’ water is still wet.

      1. 4.1.1

        PTO examiners may often not have time to read through the patents and publications cited in an applicant’s IDS dump, but defense counsels for client company patent suits [and their responsive IPR petitions] do, and can also use them for depositions of attorneys who filed them along with claims that ignored them.
        [Also, since this is supposed to be a U.S. patent law educational blog, I do file some comments that may be obvious to you and others but not to some lay or foreign readers.]


          Your last comment is too funny.

          [Also, since this is supposed to be a U.S. patent law educational blog, I do file some comments that may be obvious to you and others but not to some lay or foreign readers.]

          Your “mere personal opinion” was met with my legal response (and even a link) for a true teaching moment.

          As for your first, maybe YOU should avail yourself OF those teaching moments I provided (hint: read (g) and (h) BEFORE you type your silly implication of:

          of attorneys who filed them along with claims that 1g n0red them.

          Let’s try the Socratic method: why is your mere personal opinion of “1g n0red” a woefully errant implied slight?


          So Paul, you were not really into that “teaching moment” thing, were you?

          Or do you feel that you have nothing to learn, on that peak of Mount S of yours?

  2. 3

    After the Festo cases, many patent practitioners stopped using a Background of the Invention or even a Summary section. At one point, there seemed to be a fad among the Examiners at the USPTO of citing so-called “admitted prior art” from the Background out of context in the rejections to the point where it was abusive of the very concept of what constitutes admitted prior art. I don’t think I’ve received a rejection citing “admitted prior art” in over a decade.

    1. 3.1

      OK, I’m drafting in Europe but it seems to me that some aspects of prep & pros are intrinsic, one of them being the need for the application documents to “sell” the invention, first to the PTO and then, later, to a court. Setting the contribution to the art in the context of the relevant prior art will, in my experience, deter Examiners from formulating objections to eligibility/patentability that they would otherwise have made based on pure textual analysis of a claim presented without context.

      In other words, a specification with a Background section will carry claims of useful scope through to allowance faster,and with a cleaner PTO file wrapper, than specifications lacking a meaningful Background section.

      And afterwards? In court? Yes, anon’s profanity point is always there. But so too is the need to leave the litigators, after reading the patent, with a gut feeling that the invention as claimed is worthy of protection and will be seen as such by the court. Otherwise, the case is likely going to go to trial and appeal.

      Mind you, I live in a different world from that of the USPTO. Oftentimes, in prosecution at the EPO, I have to scrap the US-drafted claims and replace them with text drawn from the “Summary” section. When there isn’t one, the Applicant is in deep trouble (outside the USA, that is).

      How do we drafters, today, best serve the interests of our clients, intent on procuring a world-wide collection of useful patent families?

      1. 3.1.1

        First, I applaud your attempt to take a step back from your typical EPO Uber Alles writings (it’s a small step, but a step nonetheless, and I want to encourage that)

        Second, the Patent Profanity is not my profanity — the fact is the fact not because I share them, I share them because they are facts unto themselves.

        Third, the most obvious answer to your last question is to simply recognize that there is no one-size-fits-all and that one needs to respect the Sovereign-centric nature of patent law.


          anon, the last time I checked, the USA is a Member State of the PCT. Rule 5(1) of the PCT Implementing Regulations sets out what is mandatory to disclose in the specification of a patent application. Basically, you have to say what your invention is, and set it in the context of the relevant prior art.

          So drafters draft for the eventuality that their patent application will be filed at the PTO of a PCT Member State. Everywhere outside the USA, if you fail to draft in accordance with PCT Rule 5(1) there will be adverse consequences, if only because after the filing date, in a First to File jurisdiction, you can’t come up after the filing date with what you think your invention now is. If you didn’t say it to the PTO when you filed your patent application, it’s too late any time after that. See today’s snow brakes case from Dennis, for example.

          My question was about how drafters can reconcile such drafting with the old First to Invent jurisprudence and the ongoing advice of patent litigators in the USA who acquired their chops under First to Invent law.


            Meh, it’s less “under the chops” than you might think, but getting back to the beginning of your post:


            As I have mentioned to you previously (and more than once), international treaties are not typically self-enacting under US law.

            That goes for the PCT.

            In fact, in our MPEP, there are listed several items explicitly different in the US:
            http s://

            This is not an exhaustive list, but I list it as you tend not to listen to me, but might listen to the MPEP.
            Further, if you venture into how the PCT is described in that same MPEP (as
            http s://

            ), you would (or should) notice the deferential permissive language. You might understand this as somewhat akin to your own EPO “per se” and “as such” types of caveats (often big enough to drive a truck through, well at least a software/business method/truck – if you know what I mean :bigsmile; ).

            That being said — and still hewing to the bedrock principle of respecting the individual sovereigns of the world while also (still) recognizing that patent law is a Sovereign-centric law, if one is going to use a single platform to launch into several different domains (that is, Sovereigns), then sure, it may well make sense to ‘common-ize’ aspects of the disclosure that one may choose to do differently for the US Sovereign. Your comment though appears to take a different tact: one not of “choice,” but somehow imputing a US national law obligation based on (admittedly, your understanding of) law as may apply in other Sovereigns (and notably, may not be as permissive as the US-actual-implemented-PCT wording provides).

            (Note: copy and remove the extra space in the links — having some posting issues)

      2. 3.1.2

        Well, for one thing Max, there is really no excuse for any U.S. P&P practitioner still, after so many years of Fed. Cir. decisions, using the words “the invention” or “the invention is” before or after “Background of,” or “Summary of..” in a spec. That is probably the most serious “poison word.”
        It is still possible to suggest advantages or distinctions of the invention in the spec without making limiting admissions, such as pointing out possible applications of an embodiment example in a detailed description of an embodiment example.


          Others have asked why I use the word “innovation” in some of my comments.

          Paul’s point here is a clue.


          “the invention”
          I think it is pretty common for most modern practitioners to stress that EMBODIMENTS of the invention being disclosed are illustrative.

      3. 3.1.3

        Personally, I use a Background section but I keep it fairly simple, and I rarely cite “prior art”. I use it to set a broad overview of what led to the need for the invention, but I also use it sparingly.

    2. 3.2

      I am not surprised, ipguy, and the patent profanity aspects will be recognized by most readers who come to these pages without an agenda to advocate from (that is to say, without an agenda that requires suspension of critical thinking as to the detrimental effects that the judicial branch has thrust upon patent law).

    3. 3.3

      I agree that there was a time there where the office was getting a bit silly with what it would term “admissions” in the prior art. That said, I think that a lot of the efforts to avoid “admitting” that something is in the prior art are also a bit silly.

      Take the case above, for example. Suppose that the patentee had not acknowledged in the written description that springs had been used in gloves before. Do you imagine that the defendant would have neglected to adduce proof of this reality? I think that it is worthwhile to make a clear-eyed acknowledgment of the state of the art, and then go from there, rather than to try to play coy about whether something is or is not prior art to your invention.

      1. 3.3.1

        This is why, if I were Director, I would promulgate regulations requiring that all independent claims be presented in Jepson format before they will be taken up for examination.


          Lol. Thank G O D for small favors (that you have zero chance of ever being the director).

          Which reminds me — how close to that asymptotical zero are we with the actual use of that optional Jepson claim format? (that would make a good academic update).

      2. 3.3.2

        Some of those “silly” admitted prior art rejections became, after response and inquiry, 102 (f) rejections even if the admission turned out not to be about “prior art”.

        102(f) was another bar to patentability, at the time. The Japanese origin apps were notorious for 102(f) admissions. Maybe the electricals rejections bled over in to pharma (called bio-tech, back then).

      3. 3.3.3

        “Do you imagine that the defendant would have neglected to adduce proof of this reality? ”

        I disclose all relevant prior art known to the inventor in an IDS. There is nothing to be gained by mentioning it in the Background. I try to avoid mentioning prior art in the Background. The only prior art I do mention is the inventor’s own close prior art. Even then, I take great pains to avoid stating anything along the lines of how much better the inventor’s current invention is over his/her own prior art. If I give the defendant’s counsel an inch, defendant’s counsel will take a mile.



    4. 3.4

      > many patent practitioners stopped using a Background of the Invention or even a Summary section.

      I miss the old style of patents. The ‘modern’ ones all play this vagueness game, and it greatly multiplies the amount of time necessary to understand their claims.

      Yea, maybe the difference is trivial if you are a judge or litigator working on 1 patent for months. But, if you’re looking at a stack of 250 for potential problems (or even 5 cited reference in some office action or search report on fixed budgets), it hurts.

      1. 3.4.1

        Would you elaborate on what you mean by “vagueness game”?


          Well the Filter is excessively active again…

          It means that patent practitioners simply leverage what the judicial branch attempt to legislate from the Bench.

          But you already knew that, eh Ben?

          Maybe you think playing 0b tuse will get you a “shocking” admission that the legal document known as a patent is written in the legal context of what the judiciary have rendered.

          (here’s a hint: patent practitioners will ALWAYS “out-scr1ven” the judicial scr1veners)

      2. 3.4.2

        “But, if you’re looking at a stack of 250 for potential problems (or even 5 cited reference in some office action or search report on fixed budgets), it hurts.”

        Are you referring to reviewing patents for a product clearance or freedom to operate opinion?


          More of a pre-product assessment. Every other year or so, some client insists.


            The same problem comes up on the patentee side. “Here is a stack of our patents. Are any of them useful here?”

      3. 3.4.3

        The movement to avoid the so-called “profanity” should have petered out by now. It made sense back in the earlier days of the Fed.Cir. when patents were mostly held valid and a patentee lost a lawsuit from a narrow claim interpretation that was explained by the now-avoided words.

        Since recent Scotus case law has made patent validity easier to successfully challenge, the need exists to show the deficiencies of the state of the art to help in obviousness challenges.


          Not sure I can agree that by attempting to address recent SCOTUS “jurisMISprudence,” that taking a fact that is still a problem is any type of good idea. Least of all, in the part of the specification that can be taken as admitted prior art. Now, if you want to tell your story (in a clever manner), you can still add some “zest” in the detailed description portion to achieve the ends that you are hinting at (and still abide by the still-present profanity avoidance).

  3. 2

    Shocked that the write-up misses the teaching opportunity of patent profanity (or why there is essentially no “Background” section in todays patent; or why the trend [when was the last time that was shared] of the optional Jepson claim format continues its asymptomatic approach to zero.

  4. 1

    “admitted prior art would seemingly be quite relevant as part of the intrinsic analysis of claim scope”

    This assumes everybody involved with writing the specification understands how the patent system works and what its purpose is.

    That’s not the worse assumption to make but unfortunately not always accurate, especially lately.

    1. 1.1

      Lol – see post 2.

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