What is the correct priority date of US 4,851,616 A, and what are the legal ramifications if an inventor deliberately misrepresents the priority date based on an error in the patent?

Please provide your reasoning.

Hint: There are at least 12 useful pieces of information in the cover sheet (and even more in the specification), and the answer is not January 3, 1966.

cover sheet with incorrect priority date

Note: This is a lapsed patent, and the reason I am asking about this is provided in this meta post.

1 Answer 1


The "Filed" field in the grant publication says "Jan. 3, 1966". However, other information from the cover sheet conflicts with this date.

  1. No domestic benefits

    Reading through the patent, it does not claim any domestic benefit, so it was not a continuation, continuation-in-part or divisional of any other application. This grant was based on a single patent application.

  2. The Issue Date

    The issue date of the patent is July 25, 1989. If the "Filed" date were correct, then this patent would have taken 33 years, 6 months and 22 days to examine. An examiner at the USPTO could have been handed this application on his first day at the job in 1966, spent his entire career 30-year examining it, and then handed it his next of kin in 1986 to complete the job.

  3. The References Cited

    All cited references in this document are after 1966 but before January 3, 1986:

  4. The Serial Number

    Table of Filing Years and Patent Application Serial Numbers:

    • 1960 4 000,001
    • ...
    • 1965 4 423,000
    • 1966 4 518,000
    • 1967 4 606,000
    • 1968 4 695,000
    • 1969 4 788,000
    • ...
    • 1979 6 000,001
    • 1980 6 108,971
    • 1981 6 221,957
    • 1982 6 336,510
    • 1983 6 454,954
    • 1984 6 567,457
    • 1985 6 688,174
    • 1986 6 815,454
    • 1987 7 000,001

    As you can see above, a patent application filed in 1966 would have had a serial number between 04/518,000 and 04/606,000. The patent application referred to here has serial number 06/816,065, which means there is no question that the filing date was in 1986.

  5. Public Pair Transaction History

    Looking in the Transaction History, we see that the case was first docketed to the examiner on May 3, 1986, which is consistent with the other observations above, which point to 1986.

    • 05-30-1986 Case Docketed to Examiner in GAU
    • 10-10-1986 Non-Final Rejection
    • 10-20-1986 Mail Non-Final Rejection
    • 04-23-1987 Request for Extension of Time - Granted
  6. Maintenance Fees - Bibliographic Data

    The bibliographic data from the Maintenance Fees screen shows the correct Filing Date, January 3, 1986 (also note the serial number is an 06/ series):

    Maintenance Fees - Bibliographic Data

  7. Public Pair - Bibliographic Data

    The bibliographic data from the Public Pair screen also shows the correct Filing Date, January 3, 1986:

    Public Pair - Bibliographic Data

Based on all of this evidence, which is publicly available in the USPTO databases, it is clear that the correct priority date of the patent is January 3, 1986. The 1966 date is an obvious typo in the cover sheet, which is known to happen from time to time. If someone is interested in correcting it, they can submit a correction according to Section 323.01(a) Typographical Errors in Cover Sheet, and the USPTO will make the necessary correction to the cover sheet in the historical database.

Now that the correct priority date is established, what are the legal ramifications of deliberately misrepresenting information about a patent? Well, in a normal online forum, probably nothing. However, this forum has the blessing of the USPTO to identify and submit third party observations for prior art. Misrepresentation of information here would potentially fall within the scope of deceptive intent leading to Inequitable Conduct as described in this article:

Woods, AG. 2014. Withholding Information Contradicting A Legal Argument Or Misrepresenting Information Supporting That Argument May Rise To Inequitable Conduct. Mondaq Business Briefing.

Update: The Espacenet database had also propagated the incorrect priority date to their records. It was easy to report and correct, and their system now lists the correct priority date:

Corrected Priority Date

Update: Correcting the USPTO database is also possible:

323.01(a) Typographical Errors in Cover Sheet

A party who wishes to correct a typographical error on a recorded cover sheet must submit the following to the Assignment Services Division:

(A) a copy of the originally recorded assignment document (or other document affecting title);
(B) a corrected cover sheet; and
(C) the required fee for each application or patent to be corrected ([37 CFR 3.41][19]).

See 37 CFR 3.34. The party requesting correction should also submit a copy of the original cover sheet, to facilitate comparison of the corrected cover sheet with the originally recorded document.

The party filing the corrected cover sheet should check the box titled "Other" in the area of the sheet requesting "Nature of Conveyance," and indicate that the submission is to correct an error in a cover sheet previously recorded. The party should also identify the reel and frame numbers (if known), and the nature of the correction (e.g., "correction to the spelling of assignor’s name" or "correction of application number or patent number" ). The Office will then compare the corrected cover sheet with the original cover sheet and the originally recorded assignment document (or other document affecting title) to determine whether the correction is typographical in nature. If the error is typographical in nature, the Assignment Services Division will record the corrected cover sheet and correct the Assignment Historical Database.

Normally, there would be a $100 fee to file a request for correction, but in this case the error was made by the USPTO, and they will waive the fee.

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