NG LLC v. Createdhair Designs: Wig Grip Patent Dispute Decided for Defendants
NG LLC filed suit in the Central District of California alleging infringement of two wig grip apparatus utility patents and one design patent against Createdhair Designs LLC and CreatedHair, Inc. After 869 days of litigation, the court granted defendants’ summary judgment motion, holding that prosecution history estoppel barred NG LLC’s doctrine of equivalents argument.
Prosecution history estoppel ends wig grip patent dispute for defendants
NG LLC filed this patent infringement action on October 11, 2021, in the U.S. District Court for the Central District of California against Createdhair Designs, LLC and CreatedHair, Inc. The complaint alleged infringement of two utility patents — U.S. Patent No. 10,881,159 and U.S. Patent No. 10,945,477 — covering wig grip apparatus technology, as well as design patent USD879382S. The accused product was identified as the ‘Wig SECURE Crystal’ sold by the defendants.
The case turned on claim construction and summary judgment. In September 2022, the court construed the key claim term ‘the wig grip apparatus terminates at the forward periphery’ to carry its plain and ordinary meaning. By June 2023, however, the court ruled that a narrowing amendment made during prosecution of the utility patents gave rise to prosecution history estoppel, which blocked NG LLC from relying on the doctrine of equivalents to capture defendants’ product. Defendants’ motion for summary judgment of non-infringement was granted on June 27, 2023, and final judgment was entered for the defendants on February 27, 2024.
The case lasted approximately 869 days — a timeline consistent with a heavily contested district court patent matter that proceeded through claim construction and cross-motions for summary judgment before reaching resolution without trial. The estoppel ruling suggests that amendments made during patent prosecution narrowed the literal scope of the asserted claims in a way that ultimately proved decisive. NG LLC reserved all rights to appeal, leaving open the possibility that the Federal Circuit may revisit the prosecution history estoppel analysis. The design patent count (USD879382S) is not specifically addressed in the verdict language, suggesting it may have been resolved separately or effectively mooted.
Filing to settlement in 869 days
869 days — closed after nearly 2.5 years of contested litigation
Summary judgment of non-infringement entered in favour of Createdhair Designs
Why prosecution history estoppel was decisive
During prosecution of the utility patents, NG LLC made a narrowing amendment introducing the limitation ‘the wig grip apparatus terminates at the forward periphery.’ Under the doctrine of prosecution history estoppel, such a narrowing amendment presumptively surrenders claim scope for doctrine of equivalents purposes. The court found no basis to rebut the presumption, meaning NG LLC could not assert that defendants’ product was equivalent to the amended claim element — effectively foreclosing infringement liability.
Prosecution history estoppelPlain-meaning construction set the estoppel trap
The court adopted a plain-and-ordinary-meaning construction for ‘the wig grip apparatus terminates at the forward periphery,’ defining it as requiring the forward periphery of the mesh element to be the most forward portion of the apparatus. While plain-meaning constructions often favour patentees, here the construction confirmed that the narrowing amendment — not an inadvertent drafting choice — shaped the literal scope. That framing made the estoppel analysis straightforward and left NG LLC with no equivalents argument to pursue.
Claim construction rulingCross-motions revealed plaintiff’s exposure early
Defendants filed for summary judgment of non-infringement while NG LLC simultaneously sought summary judgment of infringement on the utility patents. The court disposed of both on the same day — June 27, 2023 — granting defendants’ motion and denying plaintiff’s. Running cross-motions is a common strategy to sharpen the legal dispute and avoid trial costs; here it worked decisively in defendants’ favour, collapsing NG LLC’s case well before any jury would have considered the facts.
Summary judgment strategyPlaintiff preserved appeal rights — Federal Circuit review possible
Final judgment was entered against NG LLC with an express reservation of all rights to appeal. This is a standard protective step, but it signals that NG LLC had not conceded the estoppel analysis. The Federal Circuit — which handles all patent appeals — applies de novo review to both claim construction and estoppel determinations, meaning the district court’s findings receive no deference. Whether NG LLC will pursue an appeal, and on what grounds, is not determinable from the public record.
De novo appellate review availableFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | NG LLC | Company | IP rights holder in wig grip apparatus technology — asserting US10881159 and US10945477Search in Eureka ↗ |
| Defendant | Createdhair Designs, LLC | Company | Wig accessory designer and seller — accused of infringing wig grip apparatus patents via ‘Wig SECURE Crystal’Search in Eureka ↗ |
| Plaintiff counsel | Brian R. Michalek | Attorney | Counsel for NG LLCSearch in Eureka ↗ |
| Plaintiff counsel | Jeffrey M. Jensen | Attorney | Counsel for NG LLCSearch in Eureka ↗ |
| Plaintiff counsel | Mark B. Mizrahi | Attorney | Counsel for NG LLCSearch in Eureka ↗ |
| Plaintiff counsel | Todd M. Lander | Attorney | Counsel for NG LLCSearch in Eureka ↗ |
| Plaintiff counsel | William E. Adams | Attorney | Counsel for NG LLCSearch in Eureka ↗ |
| Defendant counsel | Lance G. Johnson | Attorney | Counsel for Createdhair Designs, LLCSearch in Eureka ↗ |
| Defendant counsel | Laura V. Farber | Attorney | Counsel for Createdhair Designs, LLCSearch in Eureka ↗ |
| Defendant counsel | Steven Andrew Wilson | Attorney | Counsel for Createdhair Designs, LLCSearch in Eureka ↗ |
| Presiding judge | Judge / | Chief Judge | California Central District Court — Chief JudgeSearch in Eureka ↗ |
Stipulation of dismissal — official text
The final judgment is explicitly limited to Counts I and III — the two utility patent counts covering US10881159 and US10945477. Notably, the design patent (USD879382S) is absent from the judgment, which may suggest it was resolved on different terms or abandoned before final judgment. The court’s ruling is grounded entirely in prosecution history estoppel, not a finding that defendants’ product lacked the claimed features — a distinction that matters significantly if NG LLC pursues appeal or future enforcement with a differently drafted claim.
US10881159 & US10945477 — Wig Grip Apparatus Patents
U.S. Patent No. 10,881,159 and U.S. Patent No. 10,945,477 both protect wig grip apparatus technology — specifically, a device designed to secure a wig to the wearer’s head using a mesh element whose forward periphery constitutes the most forward portion of the apparatus. The patents appear to derive from applications filed as U.S. Application Nos. 16/819,024 and 16/276,579 respectively, suggesting a continuation or related family structure. The key claim limitation — ‘the wig grip apparatus terminates at the forward periphery’ — defines the spatial relationship of the mesh element and became the pivotal term in both construction and estoppel proceedings.
For competitors operating in the wig accessories and hair loss solution markets, these patents represent a defined claim boundary that was further narrowed during prosecution. The litigation reveals that the asserted patents, while granted, carry embedded estoppel risk that limits their enforceability beyond their literal scope. Design patent USD879382S provides a separate, ornamental layer of protection whose enforceability remains less clearly resolved by this case. Companies in adjacent spaces — including wig manufacturers, medical hair prosthetic suppliers, and accessory brands — should assess whether their products fall within the remaining literal claim scope.
Should your product team run an FTO against US10881159 or US10945477?
Any company designing, manufacturing, or distributing wig grip devices, wig securing bands, or similar head-worn hair accessory products should assess freedom to operate against this patent family. While the litigation outcome suggests the doctrine of equivalents is unavailable to the patentee due to prosecution history estoppel, the literal claim scope remains intact. A product whose forward mesh element terminates at the apparatus’s forward periphery — as literally claimed — could still face exposure. The design patent USD879382S adds a further layer worth screening separately.
PatSnap Eureka’s FTO Search Agent can map the literal claim boundaries of US10881159 and US10945477 against your product specifications, surfacing relevant prosecution history and identifying the precise amendment that created the estoppel. Eureka’s claim monitoring tools can also alert your team if NG LLC files continuation applications with broader or differently worded claims — a common post-litigation strategy when a patentee loses on estoppel grounds but believes the core innovation remains valuable.
Run a freedom-to-operate analysis on USD0879382S to assess your product’s exposure
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What this case signals for the wearable accessories IP landscape
A clean estoppel win for defendants in a niche but growing product category — with lessons for how prosecution choices constrain litigation strategy.
Narrowing prosecution amendments can become litigation liabilities
NG LLC’s loss was not decided on the merits of whether defendants copied their innovation — it was decided by a single amendment made years earlier during patent prosecution. Any company enforcing patents in the accessories or wearables space should audit prosecution histories before filing suit. An estoppel trap may already be built into the claims.
Plain-meaning constructions are not automatically safe for patentees
Patentees often welcome plain-meaning constructions as a way to preserve broad scope. This case illustrates the risk: when a claim term was narrowed by amendment, the plain meaning confirmed the narrowed version, not a broader one. Drafting counsel and enforcement counsel must be aligned on this dynamic before litigation commences.
NG v Createdhair — key questions answered
The court granted defendants’ summary judgment motion based on prosecution history estoppel. NG LLC had made a narrowing amendment during prosecution of its utility patents — specifically introducing the limitation ‘the wig grip apparatus terminates at the forward periphery’ — which the court held surrendered the doctrine of equivalents argument NG LLC needed to prove infringement.
NG LLC asserted three patents: utility patents US10881159B2 and US10945477B2, both covering wig grip apparatus technology, and design patent USD879382S. The final judgment addressed only the two utility patents (Counts I and III). The design patent count was not expressly resolved in the final judgment language on the public record.
Prosecution history estoppel arises when a patent applicant narrows a claim during prosecution to secure grant. That narrowing is treated as a surrender of claim scope for doctrine of equivalents purposes. Here, NG LLC’s amendment restricted how the mesh element’s forward periphery was defined, and the court held that NG LLC could not later argue defendants’ product was equivalent to that narrowed element.
The final judgment, entered February 27, 2024, expressly states that NG LLC reserved all rights to appeal. Whether NG LLC subsequently filed an appeal with the U.S. Court of Appeals for the Federal Circuit is not determinable from the case record reviewed here. The Federal Circuit applies de novo review to both claim construction and prosecution history estoppel — meaning the district court’s analysis would receive no deference on appeal.
The accused product is the ‘Wig SECURE Crystal’ sold by Createdhair Designs LLC and CreatedHair, Inc. It is a wig grip or wig securing accessory. NG LLC alleged this product infringed the mesh element and forward-periphery features claimed in its utility patents. The court ultimately found no literal or equivalent infringement, entering judgment for defendants.
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