United States: Marked Products And Past Payments Under A Licensing Contract May Be Circumstantial Evidence That The Products Are Covered By The License

In Frolow v. Wilson Sporting Goods Co., No. 12-1185 (Fed. Cir. Mar. 15, 2013), the Federal Circuit reversed the district court's grant of SJ that fourteen tennis racket models marked with U.S. Patent No. RE33,372 ("the '372 patent") were not Licensed Articles under a licensing agreement between Jack L. Frolow and Wilson Sporting Goods Co. ("Wilson").  The Court also reversed the district court's grant of SJ that 299 other models for which Wilson had paid royalties were not Licensed Articles, affirmed the district court's JMOL that Frolow failed to prove that five tennis racket models satisfied all of the claim limitations of the '372 patent, and remanded to the district court to consider the evidence relating to patent marking and past royalty payments. 

Frolow, owner of the '372 patent related to a configuration for a tennis racket, licensed the '372 patent to Wilson.  Wilson agreed to pay royalties for "Licensed Article(s)," which the agreement defined as "tennis rackets which are covered by one or more unexpired or otherwise valid claims" of the '372 patent.  Slip op. at 2 (citation omitted).  Among other limitations, the claims of the '372 patent recite a racket having a "magnitude of Ia [moment of inertia] greater than 80 ounce-inches squared."  Id. at 3 (citation omitted).

After Frolow conducted an audit of Wilson's royalty payments, he brought suit against Wilson, alleging breach of the license agreement.  The parties initially litigated whether forty-two racket models should be considered Licensed Articles.  Based on Wilson's test data, the district court granted SJ that thirty-seven of the models did not have a moment of inertia of greater than 80 ounce-inches squared and therefore were not Licensed Articles.  The district court also rejected Frolow's argument that fourteen of these rackets were marked with the '372 patent number.  After a pretrial conference, Frolow alleged that 299 additional rackets were Licensed Articles because Wilson had paid royalties on those rackets.  The district court granted SJ in favor of Wilson that the 299 additional rackets were not Licensed Articles, because Frolow's attempt to add them to the case was untimely and violated the court's orders, and because Frolow failed to offer evidence that these rackets fell within the scope of the asserted claims.  The remaining five racket models were litigated at trial, and after the close of Frolow's case, the district court granted JMOL that these rackets were not Licensed Articles because Frolow failed to introduce evidence that the rackets included a head, a handle, a grip, or strings, as required by the claims of the '372 patent.  Frolow appealed.

"Although we do not endorse Mr. Frolow's patent marking doctrine, we do agree that the fact that Wilson marked their products with his patent number is a fact which supports his allegation that Wilson's products fall within the patent claims.  The practice of marking a product with a patent number is a form of extrajudicial admission that the product falls within the patent claims."  Slip op. at 8.

On appeal, the Federal Circuit reversed the district court's SJ ruling that the fourteen rackets marked with the '372 patent number were not Licensed Articles.  The Court first considered whether a "marking estoppel" doctrine should preclude Wilson from arguing that the marked rackets were not covered by the claims of the '372 patent.  The Court declined to adopt a marking estoppel doctrine, noting that the Supreme Court has never adopted or approved such a doctrine.  It then declined to create a marking estoppel doctrine, observing that Congress statutorily provided a remedy for false marking in the False Marking Statute of the Patent Act.  The Federal Circuit explained that marking is circumstantial evidence that the marked product is covered by a patent, and that marking may be an extrajudicial admission, which is evidence that may be considered by a court.  However, the Court acknowledged that an extrajudicial admission is not binding on the party making the admission, and can be countered by that party.  The Court also determined that adopting a marking estoppel doctrine would conflict with the evidentiary treatment of extrajudicial admissions.  The Court therefore held that the district court erred when it refused to consider evidence that Wilson had marked its rackets with the '372 patent number. 

Next, the Federal Circuit addressed whether Frolow's marking evidence raised a genuine issue of material fact in this case.  The Court noted that although Wilson had submitted evidence that the fourteen marked rackets had a moment of inertia of 80 ounce-inches squared or less, Frolow had also submitted an expert declaration contesting Wilson's test data and had provided evidence of Wilson's marking.  The Court held that marking is circumstantial evidence that the marked article falls within the patent claims and therefore can preclude SJ in appropriate cases.  The Court reversed the district court's SJ ruling and remanded for consideration of the marking evidence.

The Court then turned to whether the district court erred in granting SJ on the 299 rackets for which Wilson had paid royalties during the term of the license agreement.  The Court held that Wilson's history of paying royalties is circumstantial evidence that those rackets are Licensed Articles covered by the '372 patent.  The Court also noted that Wilson introduced evidence that eighty-two of these racket models were not Licensed Articles, but that Frolow disputed the accuracy of Wilson's data and introduced evidence that Wilson had been paying royalties for these eighty-two racket models.  Thus, the Court held that the past royalty payments were circumstantial evidence that raised a genuine issue of material fact and, accordingly, reversed the district court's associated SJ ruling.  Acknowledging the district court's discretionary power to dismiss the claims relating to the 299 racket models, the Federal Circuit remanded to the district court to determine whether the 299 racket models should be included in the proceedings.

The majority then addressed the burden of proof on remand.  Although acknowledging that neither party raised the issue of the burden of proof, the majority disagreed with Judge Newman's concurrence that contended the burden should shift to Wilson to prove that the rackets are not Licensed Articles.  Basing its decision on New Jersey law, the majority stated that the plaintiff has the burden to establish the elements of a breach of contract claim.  Rejecting Judge Newman's position, the majority observed that the cases cited by Judge Newman related to contract interpretation and do suggest that the defendant has the burden to disprove breach. 

Finally, the Court rejected Frolow's argument that the district court had erred in granting JMOL that the five racket models contested at trial were not Licensed Articles because Frolow had not introduced evidence that the rackets included a head, handle, grip, and string netting.  The Court affirmed the district court's JMOL ruling because, although the claim limitations regarding the head, handle, and grip are general in nature, the string limitation is not.   Specifically, the claims require "vertical and horizontal strings," and Frolow failed to introduce evidence that the five racket models included vertical and horizontal strings, as compared with diagonal or fan-shaped strings.  Therefore, the Court held that the district court did not abuse its discretion in granting JMOL for the five racket models contested at trial.

Judge Clevenger wrote separately to explain "why this is an unusual case."  Clevenger Additional Views at 1.  Judge Clevenger explained that, although the district court must consider the evidence of marking on remand, the evidence is not necessarily admissible to a jury.  Judge Clevenger suggested that, in this case, the fourteen marked racket models did not satisfy the claim limitations and the marking evidence may be of limited probative value that is outweighed by the risk of unfair prejudice to Wilson. 

Judge Moore also wrote separately to address Judge Clevenger's additional views.  Although Judge Moore agreed that there may be circumstances where the evidence of a defendant's marking may be excluded, she did not agree with Judge Clevenger that exclusion applied in this case.  Judge Moore argued that noninfringement had not been established because the district court refused to consider evidence of marking and Frolow did not concede that the marked products did not meet certain claim elements.  Therefore, Judge Moore stated that the application of the law should be left to the district court.

Judge Newman concurred in the Court's decision to remand, but asserted that the burden of proving that the marked racket models and the models for which royalties were paid are not Licensed Products should be shifted to Wilson on remand.  Judge Newman asserted that a jury could determine that Wilson's repeated marking could constitute a waiver that the marked rackets are not Licensed Articles.  Judge Newman also disagreed with the majority's reliance on the False Marking Statute, noting that the statute relates to qui tam actions for false marking, not a patent license or a breach of contract claim.

Judges:  Newman (concurring), Clevenger (additional views), Moore (author, additional views)
[Appealed from D.N.J., Judge Wolfson]

This article previously appeared in Last Month at the Federal Circuit, April, 2013

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.

To print this article, all you need is to be registered on Mondaq.com.

Click to Login as an existing user or Register so you can print this article.

Events from this Firm
14 Nov 2018, Conference, Washington, DC, United States

Finnegan is a Silver sponsor of the sixth annual World Intellectual Property Forum, hosted by Intellectual Professionals LLP. Finnegan partner Clare Cornell will present “Trademarks v. Company Names” and partner Patrick Coyne will present “Current Issues in U.S. Patent Law and Reform: The Next Wave”

16 Nov 2018, Seminar, Copenhagen, Denmark

Innovative companies, large and small, use patents to protect their key inventions. Obtaining valuable patents, however, requires skilled patent counsel and an in-depth knowledge of the legal requirements for securing claims that are strategically useful to your company.

17 Nov 2018, Conference, Washington, DC, United States

Finnegan partner Clare Cornell will present “Covert Trademark Use in the Internet: Licit or Illicit” at the Asian Patent Attorneys Association Conference.

Similar Articles
Relevancy Powered by MondaqAI
In association with
Related Topics
Similar Articles
Relevancy Powered by MondaqAI
Related Articles
Related Video
Up-coming Events Search
Font Size:
Mondaq on Twitter
Register for Access and our Free Biweekly Alert for
This service is completely free. Access 250,000 archived articles from 100+ countries and get a personalised email twice a week covering developments (and yes, our lawyers like to think you’ve read our Disclaimer).
Email Address
Company Name
Confirm Password
Mondaq Topics -- Select your Interests
 Law Performance
 Law Practice
 Media & IT
 Real Estate
 Wealth Mgt
Asia Pacific
European Union
Latin America
Middle East
United States
Worldwide Updates
Registration (you must scroll down to set your data preferences)

Mondaq Ltd requires you to register and provide information that personally identifies you, including your content preferences, for three primary purposes (full details of Mondaq’s use of your personal data can be found in our Privacy and Cookies Notice):

  • To allow you to personalize the Mondaq websites you are visiting to show content ("Content") relevant to your interests.
  • To enable features such as password reminder, news alerts, email a colleague, and linking from Mondaq (and its affiliate sites) to your website.
  • To produce demographic feedback for our content providers ("Contributors") who contribute Content for free for your use.

Mondaq hopes that our registered users will support us in maintaining our free to view business model by consenting to our use of your personal data as described below.

Mondaq has a "free to view" business model. Our services are paid for by Contributors in exchange for Mondaq providing them with access to information about who accesses their content. Once personal data is transferred to our Contributors they become a data controller of this personal data. They use it to measure the response that their articles are receiving, as a form of market research. They may also use it to provide Mondaq users with information about their products and services.

Details of each Contributor to which your personal data will be transferred is clearly stated within the Content that you access. For full details of how this Contributor will use your personal data, you should review the Contributor’s own Privacy Notice.

Please indicate your preference below:

Yes, I am happy to support Mondaq in maintaining its free to view business model by agreeing to allow Mondaq to share my personal data with Contributors whose Content I access
No, I do not want Mondaq to share my personal data with Contributors

Also please let us know whether you are happy to receive communications promoting products and services offered by Mondaq:

Yes, I am happy to received promotional communications from Mondaq
No, please do not send me promotional communications from Mondaq
Terms & Conditions

Mondaq.com (the Website) is owned and managed by Mondaq Ltd (Mondaq). Mondaq grants you a non-exclusive, revocable licence to access the Website and associated services, such as the Mondaq News Alerts (Services), subject to and in consideration of your compliance with the following terms and conditions of use (Terms). Your use of the Website and/or Services constitutes your agreement to the Terms. Mondaq may terminate your use of the Website and Services if you are in breach of these Terms or if Mondaq decides to terminate the licence granted hereunder for any reason whatsoever.

Use of www.mondaq.com

To Use Mondaq.com you must be: eighteen (18) years old or over; legally capable of entering into binding contracts; and not in any way prohibited by the applicable law to enter into these Terms in the jurisdiction which you are currently located.

You may use the Website as an unregistered user, however, you are required to register as a user if you wish to read the full text of the Content or to receive the Services.

You may not modify, publish, transmit, transfer or sell, reproduce, create derivative works from, distribute, perform, link, display, or in any way exploit any of the Content, in whole or in part, except as expressly permitted in these Terms or with the prior written consent of Mondaq. You may not use electronic or other means to extract details or information from the Content. Nor shall you extract information about users or Contributors in order to offer them any services or products.

In your use of the Website and/or Services you shall: comply with all applicable laws, regulations, directives and legislations which apply to your Use of the Website and/or Services in whatever country you are physically located including without limitation any and all consumer law, export control laws and regulations; provide to us true, correct and accurate information and promptly inform us in the event that any information that you have provided to us changes or becomes inaccurate; notify Mondaq immediately of any circumstances where you have reason to believe that any Intellectual Property Rights or any other rights of any third party may have been infringed; co-operate with reasonable security or other checks or requests for information made by Mondaq from time to time; and at all times be fully liable for the breach of any of these Terms by a third party using your login details to access the Website and/or Services

however, you shall not: do anything likely to impair, interfere with or damage or cause harm or distress to any persons, or the network; do anything that will infringe any Intellectual Property Rights or other rights of Mondaq or any third party; or use the Website, Services and/or Content otherwise than in accordance with these Terms; use any trade marks or service marks of Mondaq or the Contributors, or do anything which may be seen to take unfair advantage of the reputation and goodwill of Mondaq or the Contributors, or the Website, Services and/or Content.

Mondaq reserves the right, in its sole discretion, to take any action that it deems necessary and appropriate in the event it considers that there is a breach or threatened breach of the Terms.

Mondaq’s Rights and Obligations

Unless otherwise expressly set out to the contrary, nothing in these Terms shall serve to transfer from Mondaq to you, any Intellectual Property Rights owned by and/or licensed to Mondaq and all rights, title and interest in and to such Intellectual Property Rights will remain exclusively with Mondaq and/or its licensors.

Mondaq shall use its reasonable endeavours to make the Website and Services available to you at all times, but we cannot guarantee an uninterrupted and fault free service.

Mondaq reserves the right to make changes to the services and/or the Website or part thereof, from time to time, and we may add, remove, modify and/or vary any elements of features and functionalities of the Website or the services.

Mondaq also reserves the right from time to time to monitor your Use of the Website and/or services.


The Content is general information only. It is not intended to constitute legal advice or seek to be the complete and comprehensive statement of the law, nor is it intended to address your specific requirements or provide advice on which reliance should be placed. Mondaq and/or its Contributors and other suppliers make no representations about the suitability of the information contained in the Content for any purpose. All Content provided "as is" without warranty of any kind. Mondaq and/or its Contributors and other suppliers hereby exclude and disclaim all representations, warranties or guarantees with regard to the Content, including all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement. To the maximum extent permitted by law, Mondaq expressly excludes all representations, warranties, obligations, and liabilities arising out of or in connection with all Content. In no event shall Mondaq and/or its respective suppliers be liable for any special, indirect or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with the use of the Content or performance of Mondaq’s Services.


Mondaq may alter or amend these Terms by amending them on the Website. By continuing to Use the Services and/or the Website after such amendment, you will be deemed to have accepted any amendment to these Terms.

These Terms shall be governed by and construed in accordance with the laws of England and Wales and you irrevocably submit to the exclusive jurisdiction of the courts of England and Wales to settle any dispute which may arise out of or in connection with these Terms. If you live outside the United Kingdom, English law shall apply only to the extent that English law shall not deprive you of any legal protection accorded in accordance with the law of the place where you are habitually resident ("Local Law"). In the event English law deprives you of any legal protection which is accorded to you under Local Law, then these terms shall be governed by Local Law and any dispute or claim arising out of or in connection with these Terms shall be subject to the non-exclusive jurisdiction of the courts where you are habitually resident.

You may print and keep a copy of these Terms, which form the entire agreement between you and Mondaq and supersede any other communications or advertising in respect of the Service and/or the Website.

No delay in exercising or non-exercise by you and/or Mondaq of any of its rights under or in connection with these Terms shall operate as a waiver or release of each of your or Mondaq’s right. Rather, any such waiver or release must be specifically granted in writing signed by the party granting it.

If any part of these Terms is held unenforceable, that part shall be enforced to the maximum extent permissible so as to give effect to the intent of the parties, and the Terms shall continue in full force and effect.

Mondaq shall not incur any liability to you on account of any loss or damage resulting from any delay or failure to perform all or any part of these Terms if such delay or failure is caused, in whole or in part, by events, occurrences, or causes beyond the control of Mondaq. Such events, occurrences or causes will include, without limitation, acts of God, strikes, lockouts, server and network failure, riots, acts of war, earthquakes, fire and explosions.

By clicking Register you state you have read and agree to our Terms and Conditions