Retractable roof construction at Arthur Ashe Stadium is subject of patent infringement, trade secret suit

“Arthur Ashe Stadium With Retractable Roof” by Richiekim. Licensed under CC BY-SA 4.0.


On Wednesday, January 11th, retractable roof system developer Uni-Systems LLC of Minneapolis, MN, filed a patent infringement suit against multiple defendants, including the United States Tennis Association (USTA). The lawsuit alleges that multiple defendants conspired to infringe upon Uni-Systems’ patents and trade secrets by planning to build a retractable roof over a USTA tennis stadium in New York. The patent infringement suit has been filed in the U.S. District Court for the Eastern District of New York (E.D.N.Y.).

Uni-Systems is asserting two of its patents in this infringement suit. Those patents are:

  • U.S. Patent No. 7594360, titled Lateral Release Mechanism for Movable Roof Panels (the “Retention Mechanism” patent). This patent claims a system for supporting a large overhead structural member for stable movement with respect to an underlying structure which includes both a transport mechanism and lateral release system. The invention achieves a retractable roof design which is compact, lightweight, mechanically simple, and more stable in extreme weather conditions.
  • U.S. Patent No. 6789360, titled Retractable Roof System for Stadium (the “Lateral Release” patent). It discloses a stadium roof assembly with a major truss spanning a distance of at least 200 feet between first and second support locations and a roof member secured to the truss. The resulting assembly is lightweight and less likely to interfere with the view of spectators within the stadium.

According to the official complaint filed in E.D.N.Y. by Uni-Systems, the allegations of patent infringement go back to 2003, when it was engaged by Indianapolis, IN-based construction firm Hunt Construction Group, Inc., to develop and install a retractable roof for the University of Phoenix Stadium, the home of the National Football League’s Arizona Cardinals. According to a Uni-Systems web page describing the project, the company had to solve engineering challenges related to extreme hot and cold temperatures seen in Arizona and the decision to use twin translucent roof panels in the construction.

As part of its work, Uni-Systems delivered information on retractable roof maintenance to the Arizona Cardinals, information which was both proprietary and confidential. After this point, Uni-Systems alleges that Hunt began to conspire to obtain trade secrets behind Uni-Systems’ roof technology with the help of NYC-based infrastructure engineering firm Hardesty & Hanover LLP, another one of the defendants named in Uni-Systems’ suit. Uni-Systems alleges that Hardesty & Hanover won a bid to take over maintenance of the University of Phoenix Stadium. Uni-Systems alleges that Hardesty & Hanover took a financial loss on the bid but the firm was able to learn Uni-Systems’ trade secrets to develop their own competitive products.

In the complaint, Uni-Systems claims that it learned of the infringement in 2011 when it discovered plans to install a retractable roof system at Arthur Ashe Stadium, home of the US Open tennis tournament in Flushing, New York. According to allegations made by Uni-Systems, Hardesty & Hanover won the engineering bid for the work with plans to have Hunt Construction handle the building of the roof. Uni-Systems notified these and other defendants of its claims of patent infringement and trade secret misappropriation in May 2016 and filed the suit in E.D.N.Y. when requests to resolve the dispute were ignored.

Uni-Systems notes in its complaint that the firm has been developing, designing and fabricating kinetic architecture for nearly 50 years, since its founding in 1968. It has developed retractable roof systems for many well-known stadiums including Marlins Ballpark in Miami, FL; Lucas Oil Stadium in Indianapolis, IN; and Minute Maid Ballpark and Reliant Stadium, both of Houston, TX. The earliest issue date of either patent asserted by Uni-Systems in this case was in September 2004.

In addition to the claims for patent infringement, Uni-Systems also identifies the misappropriation of trade secrets in this case. This includes operational software which Uni-Systems prohibits customers from sharing with others as part of the confidentiality agreement to which the company’s customers must agree. Uni-Systems’ proprietary software operates a retractable roof’s bogies, or the vehicles responsible for opening and closing a retractable roof. Other trade secrets protected by Uni-Systems through its confidentiality agreements include material selection, machining and assembly procedures. Maintaining trade secrets for many years has allowed Uni-Systems to market itself as a professional service provider for complex building construction outside of the many standardized divisions of construction, developing its own specifications for retractable roof systems.

Multiple aspects of the retractable roof design at Arthur Ashe Stadium are identified in the suit as allegedly infringing claims of the patents asserted in the suit by Uni-Systems. These construction elements include a major truss spanning a distance between first and second supports, the truss including a convex upper portion and a tensioned lower portion which are elements covered by claim 1 of the Retention Mechanism patent. Uni-Systems also identifies elements covered by claim 1 of the Lateral Release patent, including bogies and an equalizer assembly which enables the lateral movement of retractable roof panels.

Uni-Systems’ infringement suit includes two counts of patent infringement against all defendants, one for infringement of either patent asserted in the case. Uni-Systems has also filed an additional three counts against Hunt Construction and Hardesty & Hanover, one each for federal misappropriation of trade secrets in violation of the Defend Trade Secrets Act, misappropriation of trade secrets in violation of New York state law and unfair competition under New York state law. Uni-Systems’ prayer for relief seeks damages for patent infringement, including enhanced damages under 35 U.S.C. § 284, as well as damages related to trade secret misappropriation, including damages for actual loss and damages for unjust enrichment not addressed by the actual loss. Uni-Systems is also seeking both reasonable royalty and exemplary damages from Hardesty & Hanover for willful and malicious misappropriation of trade secrets.

Although the lawsuit focuses mainly on the retractable roof system construction at Arthur Ashe Stadium, it is not the only instance of infringement and misappropriation identified by Uni-Systems in its lawsuit. The firm identified a bid made by Hunt Construction last June for another retractable roof construction project, this time for the Louis Armstrong Stadium, also in Flushing, NY, and another U.S. Open venue for USTA. An article published last August by Sports Illustrated outlines renovation plans to the entire USTA National Tennis Center designed by Rossetti Inc., another one of the defendants named in Uni-Systems suit, including retractable roofs at both the Arthur Ashe and Louis Armstrong stadiums.


Warning & Disclaimer: The pages, articles and comments on do not constitute legal advice, nor do they create any attorney-client relationship. The articles published express the personal opinion and views of the author as of the time of publication and should not be attributed to the author’s employer, clients or the sponsors of

Join the Discussion

No comments yet.