MacKey v. Collins

Headline: Federal Circuit Finds No Patent Infringement Under Doctrine of Equivalents

Citation:

Court: Federal Circuit · Filed: 2026-03-30 · Docket: 24-1854
Published
Outcome: Defendant Win
Impact Score: 45/100 — Low-moderate impact: This case addresses specific legal issues with limited broader application.
Legal Topics: patent-lawpatent-infringementdoctrine-of-equivalents

Case Summary

This case involves a dispute over a patent for a "method and apparatus for detecting and characterizing subsurface anomalies." The inventor, Mr. MacKey, sued Collins, alleging that Collins infringed on his patent. The core of the dispute centered on whether Collins's technology performed the same function in substantially the same way to achieve the same result as Mr. MacKey's patented invention. The court had to determine if Collins's method was equivalent to MacKey's patent, even if it didn't use the exact same steps or components. The Federal Circuit Court of Appeals affirmed the lower court's decision, finding that Collins did not infringe on MacKey's patent. The court applied the "doctrine of equivalents," which prevents infringers from making minor changes to a patented invention to avoid direct infringement. However, in this instance, the court determined that the differences between MacKey's patented method and Collins's method were substantial enough that they did not constitute infringement under the doctrine of equivalents. Therefore, Collins was found not to have infringed on MacKey's patent.

AI-generated summary for informational purposes only. Not legal advice. May contain errors. Consult a licensed attorney for legal advice.

Key Holdings

The court established the following key holdings in this case:

  1. The doctrine of equivalents requires that the accused device perform substantially the same function in substantially the same way to achieve substantially the same result as the claimed invention.
  2. Differences between the claimed invention and the accused device must be substantial to avoid infringement under the doctrine of equivalents.
  3. Collins's subsurface anomaly detection method did not infringe on MacKey's patent under the doctrine of equivalents due to substantial differences.

Entities and Participants

Parties

  • MacKey (party)
  • Collins (party)
  • Federal Circuit Court of Appeals (company)

Frequently Asked Questions (4)

Comprehensive Q&A covering every aspect of this court opinion.

Basic Questions (4)

Q: What was the main issue in this patent infringement case?

The main issue was whether Collins's technology infringed on Mr. MacKey's patent for detecting subsurface anomalies, specifically under the doctrine of equivalents.

Q: What is the doctrine of equivalents in patent law?

The doctrine of equivalents prevents infringers from making minor, insubstantial changes to a patented invention to avoid direct infringement, as long as the modified invention performs substantially the same function in substantially the same way to achieve substantially the same result.

Q: Did the court find that Collins infringed on MacKey's patent?

No, the Federal Circuit Court of Appeals found that Collins did not infringe on MacKey's patent.

Q: Why did the court rule that there was no infringement?

The court determined that the differences between MacKey's patented method and Collins's method were substantial enough that they did not meet the criteria for infringement under the doctrine of equivalents.

Case Details

Case NameMacKey v. Collins
Citation
CourtFederal Circuit
Date Filed2026-03-30
Docket Number24-1854
Precedential StatusPublished
OutcomeDefendant Win
Impact Score45 / 100
Legal Topicspatent-law, patent-infringement, doctrine-of-equivalents
Jurisdictionfederal

Related Legal Resources

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About This Analysis

This AI-generated analysis of MacKey v. Collins was produced by CaseLawBrief to help legal professionals, researchers, students, and the general public understand this court opinion in plain English.

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AI-generated summary for informational purposes only. Not legal advice. May contain errors. Consult a licensed attorney for legal advice.

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