How Early Electromagnetic Pumps Moved Liquid Metal Using Magnetic Fields
A 1927 patent for a pump that uses electromagnetic forces to move conductive liquids without needing moving mechanical parts like pistons or impellers.
Original patent title: “Electromagnetic pump”
A 1927 patent for a pump that uses electromagnetic forces to move conductive liquids without needing moving mechanical parts like pistons or impellers. Granted to Individual in 1927 with 7 forward citations, and it is now in the public domain.
Coverage
What does this patent actually cover?
The patent describes a device that moves electrically conductive fluids, such as liquid metals, by applying a magnetic field and an electric current perpendicular to each other. This interaction creates a Lorentz force, which pushes the fluid through a conduit. Because the force acts directly on the fluid itself, the design eliminates the need for traditional mechanical components like gears, valves, or rotating blades that would otherwise wear out or leak when handling harsh molten materials.
The gap
What does this patent NOT cover?
- Does not cover pumps designed for non-conductive fluids like water or oil.
- Does not cover mechanical pumping mechanisms that rely on physical impellers or pistons.
- Does not cover systems that lack an integrated electromagnetic field source.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
Key facts
What made this novel
The invention bypasses the 'moving parts' problem by treating the liquid metal as a conductor in a motor, effectively turning the fluid itself into the rotor of an electromagnetic pump.
The Patent Drawing
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Liquid metal cooling loops in fast-neutron nuclear reactors
Molten salt processing in chemical manufacturing
Industrial die-casting equipment for molten aluminum
Why it matters
The bigger picture
This technology was a precursor to modern liquid metal cooling systems used in specialized reactors and industrial metallurgy. By removing mechanical wear points, it allowed for the handling of materials that would destroy standard pumps.
Filed
May 2, 1924
Granted
November 1, 1927
Market context
Who's building on this
Companies in this space
Modern nuclear energy companies and research labs working on molten salt reactors continue to refine electromagnetic pumping to manage high-temperature, corrosive coolants safely.
Market impact
This patent helped establish the feasibility of moving hazardous or high-temperature conductive fluids without mechanical seals, which are often the first point of failure in industrial pumping systems.
Claim 1 — Plain English
What this patent covers
The patent describes a device that moves electrically conductive fluids, such as liquid metals, by applying a magnetic field and an electric current perpendicular to each other. This interaction creates a Lorentz force, which pushes the fluid through a conduit. Because the force acts directly on the fluid itself, the design eliminates the need for traditional mechanical components like gears, valves, or rotating blades that would otherwise wear out or leak when handling harsh molten materials.
The clever bit
The invention bypasses the 'moving parts' problem by treating the liquid metal as a conductor in a motor, effectively turning the fluid itself into the rotor of an electromagnetic pump.
What it does not cover
- Does not cover pumps designed for non-conductive fluids like water or oil.
- Does not cover mechanical pumping mechanisms that rely on physical impellers or pistons.
- Does not cover systems that lack an integrated electromagnetic field source.
Patent timeline
Application submitted to the patent office
Application published, typically 18 months after filing
Patent officially issued
Patent enters public domain
This patent is in the public domain
See the Freedom to Build guide — what is free to use, what is not, and how to cite this patent.
PatentBrief Score
Impact Score
Limited data
Citation count
18/40
Early citations
Claim breadth
0/20
Narrow claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more →
Recency
0/20
Older than 20 years
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$7K – $22K
Midpoint $13K · expired or expiring · industry ×1.4
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
Claim text not yet imported for this patent
Concepts involved
Citations
Patent lineage
Cite this patent
Roller, L. H. (1927). How Early Electromagnetic Pumps Moved Liquid Metal Using Magnetic Fields (U.S. Patent No. 1,647,147). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/1647147/sound-on-film-talking-pictures
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
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Common Questions
Frequently Asked Questions
What does How Early Electromagnetic Pumps Moved Liquid Metal Using Magnetic Fields cover?
A 1927 patent for a pump that uses electromagnetic forces to move conductive liquids without needing moving mechanical parts like pistons or impellers.
Who owns patent US 1647147?
Individual owns this patent, granted in 1927.
When does this patent expire?
This patent has expired and is now in the public domain — anyone can use the invention freely.
What is patent US 1647147 cited by?
This patent has been cited by 7 later patents that build on its ideas.
What problem does this patent solve?
This technology was a precursor to modern liquid metal cooling systems used in specialized reactors and industrial metallurgy. By removing mechanical wear points, it allowed for the handling of materials that would destroy standard pumps.
What does this patent NOT cover?
Does not cover pumps designed for non-conductive fluids like water or oil.
Same assignee
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