One assignee leads the ranked field with 105 records, well ahead of the fifth-place holder at 33 and the tenth-place holder at 21. The top five assignees combine for 305 of the 1,028 records in scope, or 29.7% of the field, which means concentration exists at the very top but the majority of records still sit with a long tail of smaller filers. Anyone doing freedom-to-operate work should start with the leader’s specific claims rather than assume the whole space is owned by a handful of firms.

Filings peaked in 2017 at 81 published records and have declined since, with 2021 at 42 and 2024 at 25 — a -40% change over that three-year span. Because publication typically lags filing by around 18 months, the 2025 and 2026 figures in any dataset are still incomplete and should not be read as confirmation that the decline is continuing. Several previously active assignees show zero latest-year records, which is consistent with this lag rather than necessarily reduced activity.

G05D, covering control of non-electric variables, accounts for 10.7% of the 1,028 records in scope, while G05B, control and regulating systems generally, accounts for 7.1%. These sit alongside F04D non-positive-displacement pump hardware at 20.8%, the largest single class, and F04B positive-displacement pumps at 10.4%. Because a record can carry more than one IPC class, drive control claims often appear combined with a hardware class rather than standing alone.