Stoneridge v. ZF North America: Electronic Parking Brake Patent Dispute Ends After 1,014 Days
Stoneridge Control Devices asserted US7021415B2 — covering electronic parking brake actuator technology — against seven ZF entities in Michigan federal court. After nearly three years of litigation, the parties stipulated to dismiss all claims with prejudice, with no costs or attorneys’ fees awarded to either side.
A Multi-Entity ZF Group Defence Ends Stoneridge’s EPB Patent Claims
Filed on 11 February 2022 in the Eastern District of Michigan, Stoneridge Control Devices, Inc. brought an infringement action against a broad coalition of ZF entities — including ZF North America, ZF TRW Automotive Holdings, ZF Automotive US, ZF Active Safety and Electronics US, ZF Restraints US, ZF Gainesville, and ZF Friedrichshafen AG — alleging that two accused electronic parking brake actuators and any EPB systems incorporating them infringed US7021415B2.
The case closed on 21 November 2024 via a joint stipulation of dismissal with prejudice under Federal Rule of Civil Procedure 41(a)(1)(A)(ii). Dismissal with prejudice is a final adjudication on the merits: Stoneridge is permanently barred from re-litigating the same infringement claims against the same ZF entities in any future proceeding. Critically, the stipulation expressly provides that neither party bears the other’s costs or attorneys’ fees, suggesting a negotiated resolution rather than a clear-cut win for either side.
A duration of 1,014 days — nearly three years — before reaching a stipulated dismissal is consistent with cases that progress through substantial fact discovery or claim construction before settling or resolving commercially. The public record is silent on whether any licence, cross-licence, or other commercial arrangement accompanied the dismissal, which is typical where parties wish to protect confidential settlement terms. What drove the resolution remains unknown, but the mutual no-costs term and the involvement of ZF’s global parent (ZF Friedrichshafen AG) suggest the resolution carried commercial weight beyond the immediate litigation.
Filing to Dismissed with Prejudice in 1014 days
1,014 days — roughly 2.8 years, above the U.S. district court median for patent cases
Dismissed with prejudice: what the stipulated exit means for both parties
Rule 41 dismissal with prejudice bars all future re-filing
A stipulated dismissal with prejudice under FRCP 41(a)(1)(A)(ii) operates as a final judgment on the merits. Unlike a without-prejudice dismissal — which preserves the plaintiff’s right to refile — Stoneridge’s claims against these ZF entities are permanently extinguished. The patent itself remains valid and enforceable against third parties; only these specific infringement claims are foreclosed.
Permanent bar on re-filingStoneridge cannot re-assert US7021415B2 against these ZF entities
By agreeing to dismissal with prejudice, Stoneridge permanently surrenders its right to pursue the same infringement claims against the named ZF entities. The patent remains in force and can still be asserted against unrelated defendants, but Stoneridge absorbs its own litigation costs — estimated to run into millions of dollars for a nearly three-year dispute — with no fee recovery from ZF.
Claims extinguished vs. ZFZF entities secure permanent protection from these EPB actuator claims
All seven ZF entities named in the action obtain a permanent shield against these specific actuator infringement claims. The no-costs provision means ZF equally bears its own defence expenditure, consistent with a negotiated exit. Whether any commercial arrangement — such as a licence or design-around agreement — underpins the stipulation is not disclosed in the public record, which is standard practice for confidential settlements.
Permanent claim immunityEPB actuator IP landscape: patent remains live for the wider market
US7021415B2 survives fully enforceable for Stoneridge to deploy against other electronic parking brake competitors. For Tier-1 and Tier-2 automotive suppliers producing EPB actuator assemblies, the case signals that Stoneridge is willing to litigate broadly and at scale — engaging global corporate families across multiple entities. Any supplier without a freedom-to-operate clearance on US7021415B2 should treat this litigation as a prompt to commission one.
Patent still enforceable vs. third partiesFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Stoneridge Control Devices, Inc. | Company | Automotive electronic controls supplier — holder of US7021415B2 covering EPB actuatorsSearch in Eureka ↗ |
| Defendant | ZF North America, Inc. | Company | ZF Group entities: global Tier-1 automotive supplier and electronic safety systems makerSearch in Eureka ↗ |
| Co-Defendant | ZF TRW Automotive Holdings, Corp. | Company | Search in Eureka ↗ |
| Co-Defendant | ZF Automotive US, Inc. | Company | Search in Eureka ↗ |
| Co-Defendant | ZF Gainesville, LLC | Company | Search in Eureka ↗ |
| Co-Defendant | ZF Friedrichshafen, AG | Company | Search in Eureka ↗ |
| Co-Defendant | ZF Restraints US, Inc. | Company | Search in Eureka ↗ |
| Co-Defendant | ZF Active Safety and Electronics US, LLC | Company | Search in Eureka ↗ |
| Plaintiff counsel | Brian S. Tobin | Attorney | Counsel for Stoneridge Control Devices, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Jessica E. Fleetham | Attorney | Counsel for Stoneridge Control Devices, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Steven C. Susser | Attorney | Counsel for Stoneridge Control Devices, Inc.Search in Eureka ↗ |
| Plaintiff law firm | Carlson, Gaskey & Olds PC | Law Firm | Representing Stoneridge Control Devices, Inc.Search in Eureka ↗ |
| Plaintiff law firm | Evia Law PLC | Law Firm | Representing Stoneridge Control Devices, Inc.Search in Eureka ↗ |
| Defendant counsel | Glenn E. Forbis | Attorney | Counsel for ZF North America, Inc.Search in Eureka ↗ |
| Defendant counsel | John R. Hutchins | Attorney | Counsel for ZF North America, Inc.Search in Eureka ↗ |
| Defendant counsel | Paul Thomas Qualey | Attorney | Counsel for ZF North America, Inc.Search in Eureka ↗ |
| Defendant law firm | Banner & Witcoff, Ltd. | Law Firm | Representing ZF North America, Inc.Search in Eureka ↗ |
| Defendant law firm | Harness, Dickey & Pierce PLC | Law Firm | Representing ZF North America, Inc.Search in Eureka ↗ |
| Presiding judge | Judge N/A | Judge | Michigan Eastern District CourtSearch in Eureka ↗ |
Official order — verbatim text
The stipulation is notably symmetric: both parties agreed to dismissal with prejudice and expressly waived costs and fees in both directions. Under FRCP 41(a)(1)(A)(ii), a two-party stipulation requires no court approval and takes effect on filing. The with-prejudice designation forecloses any future re-litigation of these claims between these parties, conferring finality equivalent to a judgment — but without any judicial findings on validity or infringement that would bind third parties or create collateral estoppel in other proceedings.
US7021415B2 — Electronic Parking Brake Actuator Systems
US7021415B2, filed under application number US10/712764, protects electronic parking brake actuator technology — the electromechanical assemblies that replace traditional cable-operated handbrakes with electronically commanded clamping mechanisms. The patent sits within the rapidly expanding domain of automotive active safety and chassis control, where electrification of braking functions is driven by regulatory pressure for advanced driver-assistance systems and autonomous vehicle readiness.
For the automotive supply chain, US7021415B2 represents a commercially significant IP position: EPB systems are now standard equipment on a large and growing proportion of passenger vehicles globally, making actuator-level patents highly relevant to multiple Tier-1 and Tier-2 suppliers. Stoneridge’s willingness to litigate this patent against ZF — one of the world’s largest automotive safety suppliers — signals that the patent is treated as core IP. Competitors producing EPB actuator assemblies for OEM supply should conduct independent FTO analysis before scaling production.
Should your team run an FTO analysis against US7021415B2?
Any organisation designing, manufacturing, or supplying electronic parking brake actuators or integrated EPB systems for the U.S. market should treat US7021415B2 as a priority clearance target. The patent has survived nearly three years of adversarial litigation against a sophisticated, well-resourced opponent without being declared invalid or unenforceable — a meaningful indicator of durability. The dismissal with prejudice provides no judicial invalidity finding that other parties can rely on.
PatSnap Eureka’s FTO Search Agent can map your EPB actuator design against the claim landscape of US7021415B2, identify prior art and prosecution history estoppel that may limit claim scope, and surface related continuation or family patents that could present parallel risk. For product and R&D teams scaling EPB production, an Eureka FTO report provides documented due diligence and informs design-around decisions before litigation exposure materialises.
Run a freedom-to-operate analysis on US7021415B2 to assess your product’s exposure
Run FTO in Eureka →Similar Electronic Parking Brake & Automotive Actuator Patent Cases
Cases involving electronic parking brake actuator patents litigated in U.S. district courts, including the Eastern District of Michigan, against Tier-1 automotive suppliers.
What this case signals for the automotive EPB actuator IP landscape
A three-year, seven-defendant campaign confirms Stoneridge is an active patent enforcer in the growing electronic parking brake market.
Multi-entity defendant structures don’t deter Stoneridge-style enforcement
Stoneridge named seven distinct ZF legal entities — including the German parent ZF Friedrichshafen AG — demonstrating a willingness to pursue global corporate families across multiple subsidiaries. Competitors relying solely on subsidiary-level design freedom may face group-wide exposure if a parent is also named.
US7021415B2 remains enforceable — EPB suppliers should assess FTO exposure now
The with-prejudice dismissal does not limit Stoneridge’s ability to assert this patent against other EPB actuator producers. Any Tier-1 or Tier-2 supplier manufacturing electronic parking brake assemblies without a current FTO clearance on US7021415B2 carries unquantified litigation risk in the U.S. market.
Stoneridge v ZF — key questions answered
Dismissal with prejudice permanently bars Stoneridge from re-asserting the same US7021415B2 infringement claims against the named ZF entities. The stipulation under FRCP 41(a)(1)(A)(ii) carries the same finality as a judgment but contains no judicial findings on validity or infringement — meaning the patent remains enforceable against other parties.
Seven ZF entities were named: ZF North America Inc., ZF TRW Automotive Holdings Corp., ZF Automotive US Inc., ZF Active Safety and Electronics US LLC, ZF Restraints US Inc., ZF Gainesville LLC, and ZF Friedrichshafen AG. The inclusion of the German parent company suggests Stoneridge sought to capture the full global corporate group.
US7021415B2 covers electronic parking brake actuator assemblies — the electromechanical units that replace mechanical handbrakes with electronically controlled clamping mechanisms. EPB systems are now standard on a large share of new passenger vehicles, making actuator-level patent rights commercially valuable across the global automotive supply chain.
No. The stipulation of dismissal expressly provides that neither party is awarded costs or attorneys’ fees. This mutual no-costs arrangement is consistent with a negotiated commercial resolution, though the public record does not disclose whether any licence or other agreement accompanied the dismissal.
Yes. The with-prejudice dismissal only extinguishes Stoneridge’s claims against the named ZF entities. The patent itself remains valid and enforceable, and Stoneridge retains full rights to assert US7021415B2 against any other party producing or supplying electronic parking brake actuator systems in the U.S. market.
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