Rotary Valves & Feeder Airlocks Patents: Leaders & White Space 2026
Rotary Valves and Feeder Airlocks: Patents Behind Air Leakage, Rotor Wear and Explosion Isolation Duty
One assignee holds 37 of the 135 records in scope, while the next four combined still only bring the top five to 59.3% of all filings — concentration at the top, but not a monopoly. Filings reached a peak of 7 in 2017 and have run below that level since; the 2026 figure is a partial year and, together with the two or three years before it, is undercounted because publication trails filing by roughly 18 months. Read the recent-year drop as a data artefact first, not necessarily as declining inventive activity.
- 1WEYERHAEUSER CO37
- 2GREAT RIVER ENERGY19
- 3INT PAPER CO9
- 4DICKINSON LEGG8
- 5LOESCHE GMBH7
See the full rotary valves and feeder airlocks analysis in Eureka
- The complete ranking, not just the top five
- Every IPC branch with its share of the corpus
- The most-cited records, and where claim space is still thin
Common questions about rotary valve and airlock patents
Who are the leading patent holders in rotary valve and feeder airlock technology?
Within this 135-record dataset, one assignee leads clearly with 37 records, well ahead of the fifth-ranked holder at 7. The top 5 assignees together account for 59.3% of all 135 records, and the top 10 reach 79.3%, so filing activity is concentrated at the top even though the ranked list runs to 41 companies. Below the top 10 the field thins into a long tail of companies and individual inventors holding only a handful of filings each, which is typical for a mature mechanical component category rather than an emerging one.
What technology areas do rotary valve and airlock patents actually cover?
The IPC composition shows this set leaning heavily toward pulp, paper and cement-adjacent processing rather than generic bulk-material conveying: D21C (pulp production & treatment) covers 37.0% of the 135 records and D21H (pulp & paper compositions) covers 35.6%, both ahead of C04B (ceramics, cement & refractories) at 32.6%. B65G, the class most people would expect to dominate a conveying-equipment search, sits lower at 11.9%. Because a single record can carry several IPC classes, these percentages add up to more than 100% and should each be read against the 135-record total, not against one another.
Has patent filing for rotary airlocks slowed down?
The observable trend peaked in 2017 at 7 filings in a single year and has not matched that level since, based on data through the 2026-07-31 cut-off. That said, publication typically lags filing by around 18 months, so the last two or three years in any trend chart are understated by definition and should not be read as a confirmed decline. A fairer read is that visible activity has plateaued below the 2017 peak, with the true current rate likely higher than what has published so far.
Disclaimer. This analysis is based on Patsnap Eureka data drawn from a limited snapshot of global patent records and is provided for general information and reference only. Patent data carries inherent limitations — recent filings are under-counted because of publication lag, counts may be on a record or family basis, classification and applicant-name data may contain errors or duplicates, and the underlying search query defines the scope shown — so the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing here is an exhaustive prior-art, novelty, freedom-to-operate or validity search, nor does it constitute legal, financial or professional advice, and it should not be relied upon as such. Verify independently and review with qualified patent and legal professionals before acting on it.
Method: Filing trend and technology composition. Derived from a Patsnap search on Rotary Valves and Feeder Airlocks covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish. Every share divides by all records in scope. Data: Patsnap Eureka. See the full landscape report.