PlainPatent

CPC technology class · F03

F03B - Machines OR Engines FOR Liquids

Machines or engines for liquids. 1,544 US utility patents granted 2015–2025, with the leading assignees and year-by-year filing trajectory.

1,544
US patents granted
F03
Parent CPC class
20
Active assignees
+18%
5-yr velocity

The verdict

Machines OR Engines FOR Liquids ranks #402 of 670 CPC technology areas - 1,544 US patents granted since 2015, with filing up 18% over five years.

#402
of 670 CPC technology areas
1,544
US patents granted, 2015–2025
Lone Gull Holdings
leading assignee (49)
+18%
filing velocity, last 5 yrs
Top assignee: LONE GULL Holdings, Ltd. (49 patents)

CPC subclass F03B - MACHINES OR ENGINES FOR LIQUIDS - covers 1,544 US utility patents granted between 2015 and 2025 according to USPTO PatentsView records, within the broader CPC class F03 (MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR). See our CPC classification guide for how the system works.

The competitive landscape in F03B is shaped by 20 distinct companies actively filing in this space. LONE GULL Holdings, Ltd. leads with 49 patents, followed by GE Renewable Technologies at 28 grants and Voith Patent Gmbh at 20.

Filing activity in F03B is up 18% over the past five years versus 2015-2019, a relatively steady filing pace. All counts come directly from USPTO PatentsView and reflect US granted utility patents only.

Is F03B innovation accelerating?

US utility-patent grants per year in F03B, 2015–2025 - recent five years are up 18% versus 2015–2019.

100120140160180 20152016201720182019202020212022202320242025 138

Who leads F03B?

The 12 most active assignees in MACHINES OR ENGINES FOR LIQUIDS - wider bars mean more grants

patents

What this shows Lone Gull Holdings is the most active filer in F03B, holding 49 of the 1,544 patents in this class. Concentration at the top signals how contestable this technology area is for new entrants.

Source USPTO PatentsView, granted utility patents As of 2015–2025 grant years
View data table
Top patent holders in CPC subclass F03B
Rank Company Patents in F03B
#1 LONE GULL Holdings, Ltd. 49
#2 GE Renewable Technologies 28
#3 Voith Patent Gmbh 20
#4 Liquid Robotics, Inc. 12
#5 Differential Dynamics Corporation 12
#6 Aw-energy OY 12
#7 Flower Turbines, Inc. 11
#8 Andritz Hydro Gmbh 11
#9 Alstom Renewable Technologies 10
#10 Murtech, Inc. 10
#11 Openhydro IP Limited 9
#12 Michigan Technological University 8
#13 Natel Energy Holdings, Inc. 8
#14 Pliant Energy Systems Inc. 8
#15 Verno Holdings, Llc 8
#16 Ingine, Inc. 8
#17 Innovator Energy Llc. 7
#18 Oscilla Power Inc. 7
#19 Hydrokinetic Energy Corp 7
#20 Minesto AB 7

About This Class

CPC subclass F03B belongs to class F03.

1,544 patents were granted in this class between 2015 and 2025.

20 companies actively patent in this space.

Classification System

Cooperative Patent Classification (CPC) is a hierarchical patent classification system used by the USPTO and EPO.

← All Technology Classes Technology Rankings →

Footprint here vs. claim strategy

Each dot is a leading F03B assignee, placed by how many patents it holds in this class (horizontal) against its company-wide average claims per patent (vertical) - a read on whether the class is led by broad-but-shallow filers or focused deep-claim players.

Top 14 F03B assignees by class footprint. Bubble size = patents in F03B. Source: USPTO PatentsView (claim depth is company-wide across all classes).

Top 14 F03B assignees by class footprint. Bubble size = patents in F03B. Source: USPTO PatentsView (claim depth is company-wide across all classes). Scatter plot of 14 data points (bubble-sized by third dimension). 10152025 0102030405060 Patents in F03B Avg claims / patent (company-wide) Lone Gull HoldingsGe RenewableVoith PatentLiquid RoboticsDifferential DynamicsAw-energy OyFlower TurbinesAndritz HydroAlstom RenewableMurtechOpenhydro IpMichigan Technologica…Natel Energy HoldingsPliant Energy Systems
Top 14 F03B assignees by class footprint. Bubble size = patents in F03B. Source: USPTO PatentsView (claim depth is company-wide across all classes).

Frequently Asked Questions

What is CPC class F03B?
CPC subclass F03B covers MACHINES OR ENGINES FOR LIQUIDS. It belongs to CPC class F03 (MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR), with 1,544 US utility patents granted since 2015.
How many patents have been filed in F03B?
1,544 US utility patents were granted in CPC subclass F03B between 2015 and 2025, based on USPTO PatentsView data.
Which company holds the most patents in F03B?
LONE GULL Holdings, Ltd. leads F03B with 49 patents, making it the most active assignee in this technology area.
How is patent data for F03B collected?
Patent data comes from USPTO PatentsView, a public research dataset maintained by the United States Patent and Trademark Office. It covers all US granted utility patents and assigns CPC codes based on the technology described in each patent.
What is the difference between CPC class and subclass?
A CPC class (e.g., F03) is a broad technology category. Subclasses like F03B provide finer granularity within that category. PlainPatent organizes data at the subclass level (4-character codes) for the most useful view of technology domains.

Read our methodology - how this data is sourced, computed, and verified.

Data sourced from USPTO PatentsView - official U.S. government patent data. See our methodology for computation details. Retrieved and formatted by PlainPatent Editorial

Every figure on PlainPatent is rendered directly from USPTO source data, no number is typed in by an editor. This page draws directly on USPTO source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.