Vacuum Interrupters Patents: Who Leads, White Space 2026
- 43.5% concentration. The top 5 of 100 ranked assignees account for 1,094 of the 2,517 records in scope — 43.5% of the whole field.
- Filing peaked in 2017. Volume reached 54 that year and has since declined; 2021-to-2024 shows a -41% move, though 2025 onward is still filling in due to publication lag.
- Contact-material claims dominate. 365 records touch C22C alloys and 199 touch B22F powder metallurgy, alongside near-universal H01H switch claims, pointing to material chemistry as the busiest adjacent lane.
Filing growth compares 2021 (27 records) with 2024 (16) — a three-year span. 2024 is the most recent year we treat as complete: publication lags filing by roughly 18 months, so 2025 onwards are still filling in and any growth rate that ends there would understate the field. Top-5 share is the combined record count of the five largest assignees divided by all 2,517 records in scope (CR5), not by the ranked leaders only.
What the vacuum interrupter patent record actually covers
A vacuum interrupter is the switching core of a vacuum circuit breaker: two contacts inside a sealed vacuum envelope that separate to interrupt current without the arc products that plague oil or SF6 designs. The search behind this page pairs vacuum-interrupter and vacuum-circuit-breaker language with the specific engineering problems assignees actually claim around — contact material, current chopping, axial magnetic field control, bellows lifetime, voltage withstand and x-ray emission — rather than the device name alone, which keeps the set focused on functional claims instead of marketing mentions.
That gives 2,517 records spanning 2015 to the 2026 cut-off, concentrated overwhelmingly in switch and relay claims (H01H) but with a meaningful secondary cluster in alloy and powder-metallurgy contact materials — the part of the stack where wear, current-chopping behaviour and dielectric withstand are actually won or lost.
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Filing trend and technology composition
The two charts below use the same 2,517-record denominator throughout: the trend chart counts records by publication year, and the IPC chart shows each subclass as a share of all records, so the shares add to more than 100% because a single record can carry several classes.
Filing activity, 2017–2026
Volume peaked at 54 records in 2017. The 2021-to-2024 window shows a documented -41% move, from 27 down to 16; treat 2025 and 2026 as understated rather than as evidence of a further decline, since publication trails filing by roughly 18 months.
IPC subclass composition
H01H (switches & relays) sits under 91.7% of records, effectively the whole set, while C22C (alloys, 14.5%) and B22F (powder metallurgy, 7.9%) mark the next-busiest claim territory around contact-material engineering. H02H protective circuitry, H01B insulation and G01R measurement each sit under 5%, and H01J electron-tube claims are the smallest tracked class at 1.0%.
Shares are the percentage of the 2,517 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Vacuum Interrupters with Eureka
This page is one run against one query. Ask Eureka your own question about vacuum interrupters and every answer comes back with the patent numbers behind it.
Try EurekaThe most-cited records in this set
US9330868B2 — Contact assembly for a vacuum circuit breaker
A contact assembly and a vacuum circuit breaker for interrupting an electrical current are disclosed. The contact assembly includes an outer field generating element for generating a first axial magnetic field (AMF), and an inner field generating element for generating a second AMF opposite to the first AMF. The inner field generating element can be coaxial with the outer field generating element and can have a smaller diameter than the outer field generating element. The outer field generating element can be cup-shaped and slotted with non-radial slots to generate the first AMF.Filed by ABB Technology AG, published 2016-05-03 — a working example of dual, opposed axial-magnetic-field elements used to control arc behaviour at the contact face.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US4005297A | Vacuum-type circuit interrupters having heat-dissipating devices associated with the contact structures there… | 180 |
| 2 | US6141192A | Arcing fault protection system for a switchgear enclosure | 177 |
| 3 | US5917167A | Encapsulated vacuum interrupter and method of making same | 132 |
| 4 | US20170004948A1 | Electrical circuit protector | 121 |
| 5 | US6198062B1 | Modular, high-voltage, three phase recloser assembly | 115 |
| 6 | US5597992A | Current interchange for vacuum capacitor switch | 108 |
| 7 | US4325734A | Method and apparatus for forming compact bodies from conductive and non-conductive powders | 98 |
| 8 | US4673550A | TiB2-based materials and process of producing the same | 92 |
| 9 | JP2002180150A | Method for controlling structure of copper-chromium based contact stock for vacuum switch, and contact stock … | 90 |
| 10 | US4723589A | Method for making vacuum interrupter contacts by spray deposition | 89 |
Citation counts inside this corpus skew toward older filings, which have had more years to accumulate citations — read them as a signal of influence on the field rather than a ranking of current technical importance.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Browse MCP servers →What the numbers say about where this field is headed
Three patterns stand out once the filing trend, technology composition and assignee concentration are read together.
The field is led by a small group, not a single firm
The leader holds 404 records and fifth place holds 119 — a real gap, but not a monopoly. Combined, the top 5 account for 43.5% of all records in scope, and the top 10 push that to 64.1%, meaning more than a third of the field still sits with assignees outside the ranked leaders.
Volume is down from its 2017 peak, not accelerating
Filings peaked at 54 in 2017 and the documented 2021-to-2024 window shows a -41% move, from 27 down to 16 records. Years from 2025 onward are still filling in because of publication lag, so this should not be read as an active free-fall, but the multi-year direction through 2024 is clear.
Contact-material chemistry is the busiest secondary lane
Beyond the near-universal H01H switch claims, C22C alloys (14.5%) and B22F powder metallurgy (7.9%) form the next tier of claim density, consistent with contact-material wear and current-chopping performance being the properties assignees fight hardest to own.
Filing is split across a handful of major offices
The United States (599) and Japan (589) lead receiving-office counts, with Europe (435) close behind and the UK, India and Germany forming a second tier — a spread that points to global rather than single-market commercial interest in vacuum interrupter technology.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to vacuum interrupters, with the prior art for and against each one.
Who is filing, and where the claim space is still open
The assignee ranking runs 100 companies deep, counted in records, and is dominated at the top by long-established switchgear manufacturers rather than new entrants — but recent-year momentum has slowed even for the leaders.
One filer sits well ahead of the rest
The leading assignee's 404 records dwarf the fifth-place total of 119, but the drop to tenth place (91) is gradual rather than a cliff, suggesting a genuine tier of established players rather than one dominant firm and a scattered tail.
Even leaders show minimal latest-year output
Recent-year momentum figures show most of the largest historical filers, including several long-running switchgear manufacturers, registering zero or one record in the latest tracked year — consistent with the broader -41% multi-year filing move rather than any single company's retreat.
Co-filing is rare and concentrated in a few corporate families
Only 10 co-assignee pairs appear in the data, with the strongest pairings linking a company to its own subsidiary or historical corporate entity rather than to an unrelated partner — this looks like internal corporate-structure filing, not cross-company collaboration.
| Assignee | Recent year | YoY |
|---|---|---|
| Siemens Schuckertwerke AG | 1 | — |
| Meidensha Corporation | 0 | — |
| Toshiba Corporation | 0 | — |
| Mitsubishi Electric Corporation | 0 | — |
| Hitachi, Ltd. | 0 | — |
| Westinghouse Electric Corporation | 0 | — |
| General Electric Company | 0 | — |
| Eaton Corporation | 0 | — |
Where to take this analysis
The dataset points to specific next steps depending on whether the goal is freedom-to-operate, white-space filing, or tracking a competitor.
Check freedom-to-operate around contact materials
With 14.5% of records carrying C22C alloy claims and 7.9% carrying B22F powder-metallurgy claims, any new contact-material composition should be screened against this cluster before filing.
Run a freedom-to-operate checkMap the under-claimed branches to a first draft claim
Bellows fatigue monitoring and current-chopping suppression circuits show comparatively thin coverage relative to the H01H core, making them candidates for a first-mover filing.
Draft a claim in EurekaTrack the leaders' recent-year output
Latest-year momentum has fallen even among the top-ranked assignees, which changes the competitive read for anyone assuming the historical leaders are still filing at 2017 volumes.
Set up assignee monitoringCommon questions about vacuum interrupter patents
The dataset ranks 100 assignees by record count, and the leader holds 404 of the 2,517 records in scope, well ahead of fifth place at 119. The top 5 combined account for 43.5% of all records, and the top 10 reach 64.1%, so while the field has a clear leading tier, more than a third of filings sit outside even the top 10. This is a concentrated field, not a single-company monopoly.
Filing peaked at 54 records in 2017 and has trended downward since; the documented 2021-to-2024 window shows a -41% move, from 27 down to 16 records. Figures for 2025 and later are understated because patent publication typically lags filing by around 18 months, so the most recent years should not yet be read as confirmation of continued decline. The multi-year direction through 2024, however, is a real slowdown from the 2017 peak.
Almost all records (91.7%) carry an H01H switches-and-relays classification, which is the core mechanism claim. Beneath that, contact-material chemistry is the busiest secondary area, with 14.5% of records touching C22C alloy claims and 7.9% touching B22F powder-metallurgy claims — both tied to contact wear, current-chopping behaviour and dielectric performance. Protective circuitry (H02H), insulation (H01B) and measurement (G01R) each account for under 5% of records.
US9330868B2, assigned to ABB Technology AG, claims a contact assembly for a vacuum circuit breaker that uses two field-generating elements — an outer, cup-shaped, slotted element and a smaller-diameter inner element — producing opposed axial magnetic fields at the contact face. The design also includes an innermost conducting element for nominal current conduction. Anyone designing a dual-AMF contact geometry with this specific opposed-field, coaxial arrangement should review this filing closely before finalising a design.
Relative to the dense H01H switch-mechanism and C22C/B22F contact-material core, sub-areas such as bellows fatigue-life monitoring, current-chopping suppression circuitry and voltage-withstand test methodology show comparatively thin claim density in this dataset. These sit adjacent to the busiest classes rather than outside the field entirely, which is what makes them workable filing targets rather than unproven territory. Any filing strategy here should still be checked against the specific contact-material and AMF claims already held by the leading assignees.
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Disclaimer. This page is generated from Patsnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company’s registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.