Guntert & Zimmerman v. Godbersen-Smith — Federal Circuit Affirms Unpatentability
Guntert & Zimmerman’s patent on adjustable bolster swing legs for slipform paving machines — US9908571B2 — was found unpatentable, a ruling the Federal Circuit affirmed after 601 days of appellate proceedings. The decision extinguishes patent protection for this slipform paving technology and clears Godbersen-Smith of infringement exposure.
Federal Circuit kills slipform paving patent after full appellate review
Guntert & Zimmerman Construction Division, Inc. appealed to the United States Court of Appeals for the Federal Circuit (Case No. 22-1835) seeking to overturn a lower-level determination that US9908571B2 was unpatentable. The patent in dispute covers adjustable bolster swing legs used on slipform paving machines — a niche but commercially significant component in road and infrastructure construction equipment. Godbersen-Smith Construction Company, the respondent, had successfully challenged the patent’s validity before the appeal was filed in May 2022.
The Federal Circuit issued its judgment on January 18, 2024, affirming the unpatentability finding. The single-word disposition — ‘AFFIRMED’ — confirms the lower tribunal’s invalidity or cancellation ruling stands in full. The basis of termination is recorded as ‘Unpatentable,’ meaning the claims of US9908571B2 did not survive scrutiny under patentability standards, likely relating to novelty, obviousness, or written description requirements. As a result, Guntert & Zimmerman cannot enforce this patent going forward.
The 601-day appellate timeline is consistent with a standard Federal Circuit merits briefing cycle, suggesting no expedited or summary disposition was applied. That the court did not remand or partially reverse implies the unpatentability determination was well-supported on the record. What remains undisclosed publicly is the precise basis for invalidity — whether obviousness, anticipation, or another ground — and whether any related patents in Guntert & Zimmerman’s portfolio cover similar subject matter.
Filing to settlement in 601 days
601 days — full Federal Circuit appellate review from filing to judgment
Federal Circuit affirmed unpatentability — what this means for both parties
What ‘Affirmed — Unpatentable’ means at the Federal Circuit
An affirmance by the Federal Circuit means the appellate court found no reversible error in the lower tribunal’s unpatentability determination. The court reviewed the record and concluded the challenged claims of US9908571B2 failed to meet patentability requirements. This is a final, binding ruling — Guntert & Zimmerman’s avenue for reinstating this patent is effectively exhausted short of a Supreme Court petition.
Final appellate judgmentUS9908571B2 is unenforceable — patent claims cancelled
A finding of unpatentability in an inter partes or post-grant context results in cancellation of the affected claims. Once affirmed by the Federal Circuit, those cancellations are permanent. Guntert & Zimmerman cannot assert the invalidated claims against Godbersen-Smith or any other competitor in the slipform paving equipment market. Third parties previously concerned about exposure to this patent may now operate without that risk.
Claims cancelledSlipform paving swing leg tech enters the public domain
With US9908571B2’s claims cancelled, the adjustable bolster swing leg technology it described is no longer protected by this patent. Competitors — including Godbersen-Smith and others — may design, manufacture, and sell products embodying this technology without licensing obligations to Guntert & Zimmerman under this specific patent. The practical effect is a more open competitive landscape for slipform paving machine components.
Freedom to operate restoredGuntert & Zimmerman loses key IP protection in core product area
For Guntert & Zimmerman, the affirmance represents a significant IP setback in what appears to be a core product area. The company must now rely on any remaining portfolio patents, trade secrets, or design differentiation to maintain competitive position. The case signals that post-grant validity challenges against construction equipment patents in this segment can succeed through Federal Circuit review.
Plaintiff IP position weakenedFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Guntert & Zimmerman Const. Div., Inc. | Company | Construction equipment manufacturer — holder of US9908571B2 (slipform paving)Search in Eureka ↗ |
| Defendant | Godbersen-Smith Construction Company | Company | Godbersen-Smith Construction Co. — construction company and patent validity challengerSearch in Eureka ↗ |
| Plaintiff counsel | James R. Hannah | Attorney | Counsel for Guntert & Zimmerman Const. Div., Inc.Search in Eureka ↗ |
| Defendant counsel | Jason E. Stach | Attorney | Counsel for Godbersen-Smith Construction CompanySearch in Eureka ↗ |
| Presiding judge | Judge / | Chief Judge | Court of Appeals for the Federal Circuit — Chief JudgeSearch in Eureka ↗ |
Stipulation of dismissal — official text
The Federal Circuit’s terse ‘AFFIRMED’ disposition carries full legal weight. It confirms that every ground of unpatentability identified below was found to be supported by substantial evidence or correct as a matter of law. The absence of a remand instruction means no claim survived or requires further proceedings. For Godbersen-Smith, the ruling is complete vindication. For Guntert & Zimmerman, no further appellate recourse exists within the Federal Circuit system; only a certiorari petition to the Supreme Court — a rarely granted avenue — would remain.
US9908571B2 — Adjustable Bolster Swing Legs for Slipform Pavers
US9908571B2 (application number US15/623012) covers adjustable bolster swing legs used on slipform paving machines — the equipment used to continuously pour and form concrete road surfaces without fixed formwork. Bolster swing legs control the lateral and vertical positioning of the paving mold assembly, and adjustability in this component is critical for accommodating varying road widths, grades, and cross-sections. The patent represents an apparatus-level innovation in the mechanical configuration of these support structures.
In the slipform paving equipment market, key players including Wirtgen, GOMACO, and domestic manufacturers compete closely on machine configuration flexibility. A patent covering adjustable swing leg geometry would, if valid, create meaningful barriers for competitors seeking to offer equivalent adjustability features. The Federal Circuit’s unpatentability ruling removes this barrier entirely, potentially levelling the competitive field for bolster assembly design. Companies in this space should monitor whether Guntert & Zimmerman files continuation patents to recapture similar claim scope.
Should your team run an FTO analysis against US9908571B2?
US9908571B2 has been found unpatentable and its claims cancelled — meaning this specific patent no longer poses an infringement risk for manufacturers or contractors working with adjustable bolster swing leg technology on slipform pavers. However, product teams developing or sourcing slipform paving equipment should verify that no related patents from Guntert & Zimmerman cover the same or equivalent embodiments before concluding the freedom-to-operate position is fully clear.
PatSnap Eureka’s FTO Search Agent can rapidly identify continuation patents, divisional applications, and related filings that share priority with US9908571B2, surfacing any residual claim coverage that may affect your product design. Claim monitoring tools can also alert your team if Guntert & Zimmerman files new patents in this technology area post-cancellation — ensuring your FTO analysis stays current as the competitive IP landscape evolves.
Run a freedom-to-operate analysis on US9908571B2 to assess your product’s exposure
Run FTO in Eureka →Similar slipform paving and construction equipment patent validity cases
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What this case signals for the construction equipment IP landscape
A Federal Circuit invalidity affirmance in a niche equipment segment has implications well beyond the two parties involved.
Post-grant challenges are viable against specialist construction equipment patents
Godbersen-Smith’s successful invalidity challenge demonstrates that post-grant review proceedings are an effective strategy against patents in highly specialised construction equipment niches. Companies facing assertions from competitors holding apparatus patents on paving machine components should consider IPR or PGR as a primary defensive tool before or alongside district court litigation.
Freedom-to-operate in slipform paving is materially broader after this ruling
With US9908571B2 cancelled, manufacturers and contractors working with adjustable bolster swing leg technology on slipform pavers face reduced IP risk from this specific claim set. R&D teams developing next-generation paving equipment should nonetheless audit related patents in Guntert & Zimmerman’s portfolio, as the company may hold continuation or divisional patents covering adjacent embodiments.
Guntert v Godbersen-Smith — key questions answered
The Federal Circuit affirmed the unpatentability of US9908571B2 on January 18, 2024. The court upheld the lower tribunal’s invalidity/cancellation determination in full, with no remand. The patent, covering adjustable bolster swing legs for slipform paving machines, is cancelled and unenforceable.
US9908571B2 (application US15/623012) covers adjustable bolster swing legs for slipform paving machines — mechanical components that control lateral and vertical positioning of the paving mold. Godbersen-Smith challenged the patent’s validity, arguing it did not meet patentability requirements. The Federal Circuit agreed with that challenge on appeal.
A termination basis of ‘Unpatentable’ indicates the patent’s claims were found to fail one or more statutory requirements — most commonly novelty (§102), non-obviousness (§103), or written description (§112). In a post-grant or inter partes review context, this results in claim cancellation. The Federal Circuit’s affirmance makes that cancellation final.
Following a Federal Circuit affirmance, the only further avenue is a petition for certiorari to the U.S. Supreme Court. The Supreme Court grants certiorari in a very small fraction of patent cases and typically only when a significant legal question is at stake. No public record of such a petition is indicated by the case data available.
With US9908571B2 cancelled, the adjustable bolster swing leg technology it described is no longer patent-protected under this filing. Competitors — including Godbersen-Smith — may freely design and sell products using this technology. However, related patents in Guntert & Zimmerman’s portfolio may still cover adjacent embodiments, so a full FTO landscape is advisable before drawing final conclusions.
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