Unpublished Foreign Patent Application Invalidates Later Filed Patent

Bruckelmyer v. Ground Heaters (Fed. Cir. 2006).

Bruckelmyer has two patents on methods of thawing frozen ground so that a layer of concrete can be laid on top of the ground. The trial court found Bruckelmyer’s patents obviated by a Canadian patent application and decided the case on summary judgment.

Interestingly, the Canadian patent application included two important figures that were cancelled during prosecution.  Those figures were reportedly required for a finding of obviousness.

On appeal, Bruckelmyer argued that the unpublished Canadian patent application was not a “printed publication” under 35 U.S.C. Section 102(b) and thus, was not prior art.

The CAFC found that the original application was “publicly accessible,” and thus a prior art “printed publication” because the Canadian prosecution file was open to the public more than a year before Bruckelmyer filed his application.

A given reference is “publicly accessible” 

upon a satisfactory showing that such document has been disseminated . . . to the extent that persons interested and ordinarily skilled in the subject matter . . . exercising reasonable diligence, can locate it and recognize and comprehend therefrom the essentials of the claimed invention without need of further research or experimentation.

In re Wyer, 655 F.2d 221, 226 (CCPA 1981).

Here, the Court found that this particular application could be located because the related patent discussed a solution for the same problem addressed by Bruckelmyer’s patents.

Thus, the application was found to be prior art even though there was no evidence that it was actually disseminated.

5 thoughts on “Unpublished Foreign Patent Application Invalidates Later Filed Patent

  1. 5

    Something old, something new Part 1

    A few weeks ago, the Federal Circuit decided an interesting case, Bruckelmyer v. Ground Heaters, construing the printed publication prong of 35 USC 102(b). The case garnered a bit of attention because the court went a bit further than it had before i…

  2. 4

    If unpublished drawings from the file history are publications, are the entire contents of the file history (including the office actions) publications as well?

    If so, can an office action that states that it is obvious to combine/alter certain references create — as to later filed applications — a teaching-suggestion-motivation to combine/alter those references once the file history is publicly available?

    Further, could an office action’s characterization of the reference’s disclosure be relevant to how that reference is later interpreted or combined?

    In view of this case, a defendant might want to search the USPTO to see how key pieces of prior art have been combined or characterized by examiners. For example, the defendant could search on the REF field in the USPTO’s advance search page: link to patft1.uspto.gov

  3. 3

    You are correct Dennis. Canadian patent applications filed in 1982 were not published after 18 months. This change to Canadian patent law did not occur until the late 80s.

    To quote from the Canadian Manual of Patent Office Practice:

    “All patent applications, except those filed prior to October 1, 1989 and documents on file in connection therewith, shall be open to public inspection after the expiration of an eighteen-month confidentiality period (subsection 10(2) of the [Canadian] Patent Act).”

    Kevin E. Holbeche
    Hofbauer Associates

  4. 2


    In this case, the prior art patent application was filed in 1982. I believe that the rules at that time regarding publication of patent applications may have been somewhat different.

  5. 1

    David J. French writes:

    Regarding the “publication” of Canadian patent applications, these documents are “laid open” as of exactly 18 months from the priority date. This includes allowing access to the physical file at the patent office and the posting of a copy of the specification as filed on the Canadian Intellectual Property Office web site public search page:

    CIPO – Canadian Patents Database
    link to patents1.ic.gc.ca.

    The posted documents are “as filed” until the patent is granted. Then the granted patent is posted.

    David J. French,

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