Warning: Do Not Rely on the Experimental Use Exception to 102(b)

Atlanta Attachment v. Leggett & Platt (Fed. Cir. 2008)

The CAFC once again reaffirmed patent law’s parallel to Chicago democracy: File early and often.

The patentee, Atlanta Attachment, won a summary judgment on issues of infringement and validity. Missouri based defendant Leggett & Platt appealed — arguing that the patented sewing machine had been “on sale” for more than one year before Atlanta Attachment filed its patent application.

The on sale bar of 102(b) invalidates an issued patent that was on sale prior to the one-year critical date. In Pfaff, the Supreme Court defined “on sale” as requiring an embodiment of the claimed invention being subject to a commercial offer for sale and being ready for patenting at the time of the sale. The on sale bar can be negated in certain cases where experimentation was still occurring.

Facts: Atlanta Attachment was working with Sealy to develop a special ruffle producing sewing machine. Over the course of a few years, several prototypes were sent to Sealy for experimentation. Each one was returned to the plaintiff for improvements. The third prototype included all of the claimed elements. Atlanta Attachment invoiced Sealy and was paid for the prototype. Instead of delivering the prototype, however, Sealy merely tested the prototype at the patentee’s facility and was later refunded its purchase price. At that time. Sealy made further suggestions regarding changes. In addition, Atlanta Attachment had offered to sell 50 production units prior to the critical date.


  1. On Sale: Although never actually delivered, prototype was sold an invoice was sent and paid. Additionally, the offer to sell the 50 production units constitutes an offer to sell. Here, the invention was considered on sale because the asserted claim was broadly written – even though the prototype was not the eventual preferred embodiment.
  2. Experimental Use: First, the CAFC held that the experimental use exception does not apply after a commercial offer for sale has taken place. Additionally, Atlanta Attachment cannot claim the experimental use exception for Sealy’s tests since “experimentation conducted to determine whether the invention would suit a particular customer’s purposes does not fall within the experimental use exception” and because Atlanta Attachment did not control the testing. This is a subtle point – the patentee apparently retained control over the device by keeping it in its facility, but did not control the testing of the device.
  3. Ready for Patenting: A prototype that is reduced to practice and works for its intended purpose is ready for patenting. The “intended purpose” here is shaped by the patent claim. And, later refinement of a device does not mean that it wasn’t ready for patenting.

Thus the claim is invalid under the on sale bar of 35 U.S.C. §102(b). Additionally, the CAFC asked the court to reexamine whether the patentee’s failure to submit information about the prototypes would be sufficient to lead to a finding of unenforceability due to inequitable conduct.

Concurrence: Judges Prost and Dyk joined the majority opinion, but also penned a separate concurring opinion begging for en banc review of the “confusing” jurisprudence on the experimental use exception to 102(b). “Without considering these issues in a comprehensive manner in future cases, we will never escape from the confused status of our current caselaw.” They specifically believe that this and other CAFC decisions are wrongly decided because of the absolute disregard of any experimental use after an invention is reduced to practice.

22 thoughts on “Warning: Do Not Rely on the Experimental Use Exception to 102(b)

  1. 21

    Malcolm: You say that best practice would be to state that the experimental use exception no longer exists. How would you advise a small R&D company that relies on this exception more often than not in order to create the product according to the customer’s specifications?

    In these cases the “offer to sell” is typically a proposal that states for X dollars we will develop a product meeting your specifications. The customer does no testing, only the inventor. The inventor then delivers a final product or drawings/schematics for the product that conforms to the specifications requested. The inventor will not mass produce/sell the device and makes no offer to do so, only to develop the product because manufacturing is not the business model of the inventor. The customer must figure out who will mass produce it and where. The inventor assigns all IP rights to the cutomer as part of the development contract.

    The only problem I see is if the proposal contains sufficient details so as to be ready for patenting when the offer is made and the customer or inventor wait more than one year from the offer date to file a patent application (depending on who has rights to file). If this is not the case, then the experimental use exception should still apply and it would hurt buisness to say it doesn’t.

  2. 20

    “To have my desire for precision in such discussions (and in Fed. Circuit opinions) referred to as pedantry by one of your visitors is disappointing.”

    Your concern has been noted. A representative may be contacting you for additional information.

  3. 19

    With all due respect Mr. Code_red,
    here’s the thing: Give it a rest.
    You’ll thank me in the morning.

  4. 18

    Dennis – Your explanation and summary are OK by me. On the other hand, this is a blog for professionals covering developments in patent law – hosted by a law professor no less. To have my desire for precision in such discussions (and in Fed. Circuit opinions) referred to as pedantry by one of your visitors is disappointing.

  5. 17

    Code_red & Leopold: I think we’re talking around the same issue here. The court here is clearly not using the “exception” term to require a particular burden of proof. Rather, I would interpret its usage as in a post TP Labs sense — as the most natural label for considering whether experimentation negates a public use or sales offer.


  6. 16


    I never said you were wrong, I said you were being pedantic. A footnote in the present case makes the point you’re making. But the court uses the term 8 or 9 times. Apparently they are less worried about our confusion than you.

  7. 15

    For those of you who insist that “experimental use” is an “exception” to the public use statutory bar, my criticism of that characterization is more than semantic. Such a characterization suggests that once a “public use” is shown, the burden would shift to the patentee to establish that the “public use” was experimental, i.e., an “exception.” No offense Dennis, but the Federal Circuit has rejected that notion and in fact has rejected the “exception” concept for that very reason. I direct you to the discussion of this very issue in TP Laboratories, Inc. v. Professional Positioners, 724 F. 2d 965, 220 USPQ 577 (Fed. Cir. 1984). I rest my case.

  8. 14

    “I interpret your post as a statement that KSR removed long felt need as a secondary consideration of non-obviousness.”

    Of course not.

    Long-felt, but unmet needs rarely occur. Yet to read a random sample of patent applications, you would think there are all sorts of long-felt, unmet needs. I was merely agreeing with Mr. Mooney because the vast majority of extensive background sections will not prove that long-felt need, but all of them will constitute admissions that can be used to show a need that would provide the post-KSR “reason” for combining/modifying the prior art. (In fact, I would bet the examiner doesn’t even have to consider self-serving backgrounds as evidence of a secondary consideration. Wouldn’t you have to submit a declaration/evidence for that?)

  9. 13

    In my mind, experimental use is clearly an ‘exception’ to on sale and public use bars of 102(b). Arguments regarding experimental use only need arise when the elements of 102(b) have been shown. A that point, the statutory bar can be negating by showing that the use was experimental.

    Beyond the logic, I use the phrase “experimental use exception” because that is the phrase used by the court to describe this judge-made law.

  10. 12

    Code_red is correct. There is no experimental use exception. Sure, the “exception” phrase is used a lot, but it tends to confuse. A “bar” is a bar. If there is a barring public use, then the patent is invalid; there are no exceptions. “Pedantry” doesn’t help. If your analysis is to be taken seriously, precision counts.

  11. 10

    “The topic title that introduces this thread is conceptually inaccurate.”

    Pedantry. Dennis didn’t make up the term “experimental use exception.” In any case, if you don’t believe that there is such a thing, then the title is especially good advice.

  12. 9

    Interesting observation Yorrick, that US advocacy leaves something to be desired. I take instructions from US patent attorneys all year round, and their instructions seem perfectly clear to me. Don’t see any lack of communication skills there. It’s their jurisprudence I struggle with. Now to the SF point, that it’s so sad when an inventor X writes to the PTO with an attractive story of problem addressed and problem solved, and that X is a silly boy. Doesn’t he know that this is exactly the wrong thing to do. For the US jurisdiction, never, ever, write what you think you’ve contributed to the art. Anything you write about your invention will be used against you, so best say nothing. That’s US jurisprudence out of line with 1) common sense and 2) the rest of the world, and handicaps that inventor from getting useful protection everywhere except the US homeland. ROW can think itself lucky that domestic US patent law is so much out of line with everywhere else. When US patent attorneys figure out that they need to draft counter to good domestic US practice to have any chance of getting, outside the USA, the full measure of protection that their contribution deserves, heaven help ROW. No wonder China and India are shouting out how great it will be for their industry when the US falls into line with ROW patent law. Think: Brer Rabbit and the thornbush.

    Yorrick, you are of course quite correct, that US patent attorneys see nothing to admire in the EPC. But that’s because they are simply not looking. Judge Rader looks though. He’s often over here. And he’s restless.

  13. 8

    The topic title that introduces this thread is conceptually inaccurate. There are no “exceptions” to the public use statutory bar of 102(b). The use is either public or it is not. An experimental use is not a public use.

  14. 7

    SF – I interpret your post as a statement that KSR removed long felt need as a secondary consideration of non-obviousness.

    What is the basis for your statement?

    KSR indeed identified “market pressure” as a motivation” to modify/combine, but “market pressure” is not synonymous with long felt need.

  15. 6

    “Then again, in the roiling aftermath of KSR I’m sure you’ll still find pleny of US applicants still filing cases with extensive background sections discussing the ‘need in the art’ for a solution to ‘problem X.'”

    Sad, but true.

  16. 5

    The U.S. can admire Europe for many things. I would question whether their collective patent codes rank among them.

    I strongly doubt your suggestion that the Federal Circuit “hankers” for a new Statute. Rather, they “hanker” for competent counsel to advance skillful arguments interpreting the present laws.

    I have no doubt whatsoever whether anyone here is deceived that You are “*beginning* to think that the CAFC is jealous of Europe.”

    hanker. intr.v. han·kered, han·ker·ing, han·kers
    To have a strong, often restless desire. [Perhaps from Dutch dialectal hankeren; see konk- in Indo-European roots.] The American Heritage® Dictionary of the English Language, Fourth Edition. Retrieved February 23, 2008, from Dictionary.com website: link to dictionary.reference.com

  17. 4

    I’m beginning to think that the CAFC is jealous of Europe. After all, in the 1970’s Europe studied very carefully indeed all the problem areas in the then US Patent Statute, the UK Statute, the German Statute etc, before getting down to writing their own honed-down brand spanking new supra-national, pan-European Patent Convention. The CAFC hankers after a new Statute too.

  18. 3

    In looking back at Pfaff and other on-sale cases, there is some confusion but the cases can be synthesized.

    Basically, under Pfaff the one-year period starts with the later of 1) a commercial offer for sale, and 2) the invention being ready for patenting. If it is reduced to practice, it is definitely ready for patenting.

    Where an invention has been reduced to practice, “experimental use” evidence goes generally to whether the sale is a “commercial” sale or not. Here, evidence of experimentation is key (see Judge Linn’s remarks in the EZ DOCK opinion cited below.)

    If an invention has not been reduced to practice but has been a subject of a commercial offer, then development work can be considered in determining whether the invention is ready for patenting or not.

    In theory, where an invention has been reduced to practice, it should be much tougher to avoid the bar based on evidence of additional development than if it has not been reduced to practice. However, in a quick review of cases, it seems like the opposite has been true. E.g., Pfaff had not reduced to practice but was barred; the EZ DOCK inventors had reduced to practice but were not barred.

    The best guidance may be the “additional views” of Judge Linn in the EZ DOCK case from the CAFC, Jan. 15, 2002.

    (I also note that it is incorrect to state that “The on sale bar can be negated in certain cases where experimentation was still occurring.” The experimentation goes to whether the bar has been met or not, but does not negate it once the bar exists.)

  19. 2

    Perhaps the best advice for clients who are serious about their IP is to assume that the experimental use exception to 102(b) does not exist.

  20. 1

    Interesting that the invalidating activities occurred just shortly after the Pfaff decision.

    One would hope that a significant Supreme Court case would heighten the sensibilities of the IP holder (or prospective IP holder).

    Then again, in the roiling aftermath of KSR I’m sure you’ll still find pleny of US applicants still filing cases with extensive background sections discussing the “need in the art” for a solution to “problem X.”

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