Prosecution History Leads to Limiting Preamble

Bass Pro v. Cabela’s (Fed. Cir. 2007).

Bass Pro owns a patent covering a vest with an attached seat. In April 2003, Bass Pro sued its arch-rival Cabela’s for patent infringement and the parties quickly settled with Cabela’s agreeing to stop infringing under a consent decree signed by the judge.  A year later, Cabela’s introduced a new product — a backpack with an attached seat. Bass Pro brought a contempt proceeding.

Modified Product Contempt Rule: When an enjoined party produces a modified device, a contempt order can issue only after a showing that the modified device infringes the patent.

It appears that Cabela’s accused backpack exhibits every element in the body of Bass Pro’s claim 1. The only difference is the preamble — Bass Pro’s preamble is directed to a vest and seat combo — not a backpack. 

The district court, seeing the evidence, decided that the vest preamble should not be limiting — thus finding that the ‘vest’ claim covers the backpack product.

Amended Preamble: Ordinarily, a preamble does not create a cause for limiting the claim scope.  In this case, however, the prosecution history led-us out of the ordinary.  During prosecution, Bass Pro had amended the preamble to add the vest term (replacing the original ‘garment’). In addition, throughout prosecution Bass Pro had discussed its “vest” in contrast to prior art backpack-chair combos.

It is clear that this patentee procured the patent based on the “unique combination of vest and pivotable seat member” stressed in the prosecution history, where the applicant placed these limitations in the claims. The district court erred in holding that the “vest” of claim 1 was not a material limitation to the claim.

On the correct claim construction the vest is a material element, and the claim cannot reasonably be found to be literally infringed.


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13 thoughts on “Prosecution History Leads to Limiting Preamble

  1. 13

    The preamble can limit the claim, for example a structural limitation can be read into the claim – there is case law on this – some reported on this site. Its a fallacy that the premable has no effect.

  2. 11

    Assuming the summary as posted is accurate, I see no problem with this case and support the decision. Obviously, if you argue or rely upon preamble terms they can be used to limit your claim. I believe they should be used.

    This is one of the reasons I always like to have at least one independent claim that reads “An apparatus, comprising…” , “A system, comprising…” , “A method, comprising” , etc.

  3. 10

    I don’t really understand this decision. If I understand it correctly, claim 1 is limited to “A vest comprising….”. The term “vest” was introduced during examination and the inventor referred to vest throughout the examination proceedings.

    However, a product which is a backpack infringes the claim?

    As far as I understood it, everything you say during examination can and will be used against you during infringement proceedings???

    Or is it the interpretation of the court that the backpack is actually a vest with a bag connected to it. So the infringing product is considered as a vest with a seat and a bag connected to it?


  4. 9

    This case seems fairly straightforward because, like the “iron bucket”, there is no question what is being described. Iron is iron is iron, and I think there can be little doubt that a claim to an “iron bucket” is limited to buckets containing iron (or, I suppose, some alloy of iron), regardless of whether “iron” is recited in the body in the claim. A more difficult question may be: when is a container a “bucket”?

    That’s the why the worst preambles for potential infringers are those preambles which recite some term that is impossible to define without reading the specification and/or prosecution histories. Terms like “pharmaceutically active” or “damage resistant” or “capable of accelerated blah blah” in the preamble are often inserted during prosecution to distinguish an applicant’s claims from one or more pieces of cited art, but what if the Examiner ignores the preamble and focuses on some other aspect of the claims? If the vague preamble terms are never expressly defined and never clearly relied on during prosecution, do the preamble terms breathe “life and meaning” into the claims? And if not, why aren’t the claims indefinite for reciting the meaningless gobbledy-gook which nobody knows what to do with?

    I think the fact that a claim which recites a “A vest, comprising …” has to go to the Federal Circuit before an accused infringer knows whether the claim is limited to “vests” demonstrates how badly the CAFC has failed in this area of claim construction.

  5. 8

    The rule for preambles (at least the rule that prosecutors must assume as a practical matter) is simple –

    – if the defendant raises non-infringement, the preamble is limiting.

    – if the defendant raises invalidity, the preamble is not limiting.

    Thus, the preamble should use only words that are also in the claim body.

  6. 7

    I’m interested in the question immmediately above. Seems to me there has been too much forgiveness, up to now, for patent attorneys who carelessly write their claims too narrow. Europe put a stop to that when the peripheral claiming Brits displaced the former German “central claiming” system (Think: Keep Off The Grass sign in the middle of the protected area). My question: will the CAFC also be taking a stricter line on patent attorneys who carelessly write “Iron bucket” as their preamble, when they had every opportunity to write “Metal” bucket? What, for goodness’ sake, is the service that patent attorneys render to clients when they “draft” a set of claims? How else do you balance fair protection for the inventor with reasonable legal certainty for readers of the patent?

  7. 6

    I’ve never really understand the concept that the preamble has no limiting effect on a claim..
    if i claim an iron bucket comprising a handle and a pail, have I not limited the claimed bucket to an iron one?

  8. 5

    Since it is known that the “breathes life into the claim” standard for importing a preamble’s limitations gives a most uncertain result, is there ever a good reason for drafting a preamble encompassing less than that encompassed by the body of the claim?

  9. 4

    That is, once an element is used in the preamble and the element is an essential one in the body, do not be afraid to use it throughout the body of the claim.
    However, if that element is not used in the preamble, do not try introducing it in the body if that element is not essential to function.

  10. 3

    This case seems to reaffirm what some of us already know in that anything you say can be used against you.

    Of course, prosecution history will be used against you.

    Also, examiners may or may not give weight to a preamble. Thus, if you are going to rely on an element, put it in the body of the claim.

    Whether a preamble breathes “life and meaning” into a claim can be vague. If you don’t want something potentially being held against you, don’t put it in the preamble.

    Thus, I personally do not use lengthy preambles because examiners may not give weight to a preamble and because a preamble may be used against you in litigation. If you require a necessary element, put it in the body of the claim.

    That being said, Cabela’s, Bass Pro, Gander Mountain, etc. are all fun places to visit.

  11. 2

    In Europe, it can make a decisive difference to things, right from the outset, what preamble you choose. It affects the scope of the EPO search, the formulation of obviousness objections, and how the claim is interpreted after issue. So, looking forward to future CAFC jurisprudence, and more “new law” from the CAFC, claim preambles could be another issue on which the CAFC gets the chance to write “Be careful what you ask for”.

  12. 1

    Although the Federal Circuit opinion doesn’t mention it, I wonder if the result would have been different if the defendant had had some notice that Bass Pro considered the patent to cover backpacks or if the issue had come up during the case itself. Even though the claims might have been broad enough to cover a backpack, a finding of contempt seems kind of severe (the district court docket shows that the judge awarded $23K in lost profits and $21K in attorneys fees) where the preamble might seem to suggest to defendant that the patent didn’t cover backpacks.

    On the other hand, the district court judge had observed the original litigation and did make a finding of contempt, so perhaps he thought that Cabela did have notice [even though he didn’t mention it in his contempt order]. The district court’s reaction does seem kind of odd to me, even looking at the whole record.

    That being said, what does everyone think about the merits of the decision? I had a case where a preamble was used by the patentholder to limit the claims to avoid prior art, which didn’t seem right to me at the time — does this change things?

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