Evnroll Putters v. Karsten Manufacturing: Golf Putter Patent Dispute Frozen by USPTO Reissue Proceedings

Introduction

A patent infringement battle over golf putter technology has been quietly frozen in Arizona’s federal courts since October 2020 — a procedural deep freeze that offers a masterclass in how USPTO reissue proceedings can fundamentally reshape litigation strategy. Filed August 8, 2019, Evnroll Putters, LLC v. Karsten Manufacturing Corporation (Case No. 2:19-cv-04908, D. Ariz.) centers on U.S. Patent No. 9,943,735 B2 and allegations that Karsten’s commercially prominent PING® Vault Putter and PING® Cadence TR Putter infringe Evnroll’s patented putter face technology.

Rather than proceeding to trial, the case has been administratively closed as of January 30, 2026 — not because either party prevailed, but because the litigation remains suspended pending the resolution of reissue applications Karsten filed with the USPTO. For patent attorneys, IP professionals, and R&D teams operating in the sporting goods and precision manufacturing sectors, this case illustrates a critical intersection between district court patent litigation and USPTO post-grant practice.

Case Overview

The Parties

The Patent at Issue

This landmark case involved U.S. Patent No. 9,943,735 B2 (Application No. 14/333,497), covering innovations in golf putter face design. While the full claim scope was not detailed in available docket records, the patent relates to structural or geometric features of putter faces — technology directly embodied in Evnroll’s competitive differentiation strategy.

• • US 9,943,735 B2 — Golf putter face technology

The Accused Products

Karsten’s PING® Vault Putter and PING® Cadence TR Putter are the accused products. Both are premium, commercially successful putters sold globally. Allegations that these flagship products infringe a competitor’s patent carry significant market and reputational implications for Karsten.

Legal Representation

Plaintiff (Evnroll): Frank Garrett Long of Dickinson Wright PLLC
Defendant (Karsten): Daniel Price Crane, David A. Roodman, Emma Harty, Jacob Alexander Maskovich, and Jason Scott Meyer of Bryan Cave LLP / Bryan Cave Leighton Paisner LLP (Phoenix and St. Louis offices), with additional representation from Womble Bond Dickinson (US) LLP – Phoenix

Karsten’s notably larger litigation team signals the seriousness with which it approached its defense strategy.

Litigation Timeline & Procedural History

Filed in the U.S. District Court for the District of Arizona before Chief Judge Douglas L. Rayes, the case moved through its initial pleading phase before Karsten took a decisive defensive step: filing Reissue applications with the USPTO in late 2020. The court agreed to stay proceedings pending USPTO disposition, a common but consequential procedural choice.

For over five years, the parties filed status reports every four months — a rhythmic acknowledgment that the reissue proceedings remained unresolved. When the court moved to administratively close the case in January 2026, neither party objected, suggesting both sides are content to await USPTO outcomes before resuming litigation.

The total case duration from filing to administrative closure spans approximately 2,366 days — a timeline shaped almost entirely by post-grant proceedings rather than trial preparation.

The Verdict & Legal Analysis

Outcome

This case has not been resolved on the merits. The Arizona District Court administratively closed Case No. 2:19-cv-04908 on January 30, 2026, preserving the right of either party to reopen proceedings upon notifying the court of readiness to proceed. No damages have been awarded, no injunction has been issued, and no finding of infringement or invalidity has been made at the district court level.

The Strategic Role of Reissue Applications

The pivotal procedural event in this case was Karsten’s filing of Reissue applications at the USPTO following the lawsuit’s initiation. A reissue application under 35 U.S.C. § 251 allows a patent owner — or in strategic contexts, a third party through related mechanisms — to correct errors in an issued patent, potentially narrowing or broadening claim scope.

Here, Karsten’s reissue filings served as a potent defensive instrument. By initiating USPTO proceedings that could alter the very claims Evnroll was asserting, Karsten created grounds to pause the district court litigation entirely. Courts routinely stay patent cases pending USPTO reexamination or reissue proceedings because the outcomes can moot or fundamentally reshape infringement and validity disputes — conserving judicial resources and potentially mooting the entire lawsuit.

Legal Significance

This case reinforces several important principles in patent litigation practice:

1. Stays pending USPTO proceedings remain a powerful defense tool. When a defendant can identify viable grounds to challenge patent claims at the USPTO, seeking a stay can dramatically alter litigation economics and timelines.
2. Reissue proceedings can extend litigation uncertainty indefinitely. A case filed in 2019 remains unresolved in 2026 primarily due to administrative proceedings — a reality that patent plaintiffs must factor into litigation planning.
3. Administrative closure is not dismissal. The case remains live and can be reopened. Patent holders should not interpret administrative closure as a loss; it preserves all claims pending USPTO outcomes.

Industry & Competitive Implications

The golf equipment industry is a surprisingly active arena for patent litigation, given the technical precision involved in club and putter design. Face geometry, groove patterns, and weight distribution technologies are the subject of meaningful IP portfolios held by both major OEMs and specialized manufacturers like Evnroll.

For Karsten and PING®, defending its flagship Vault and Cadence TR putter lines from infringement findings is commercially critical. A finding of infringement could require design changes, royalty payments, or injunctive relief affecting active product lines.

For Evnroll, a favorable USPTO reissue outcome — one that confirms or strengthens its patent claims — could significantly improve its litigation position when the district court case is reopened. Conversely, if the reissue process narrows Evnroll’s claims, Karsten’s non-infringement defense becomes substantially stronger.

More broadly, this case illustrates a trend visible across industries: defendants are increasingly using USPTO post-grant proceedings as primary litigation management tools, sometimes achieving de facto resolution through claim cancellation or amendment before a district court ever reaches the merits.