PlainPatent

CPC technology class · F23

F23N - Regulating OR Controlling Combustion

Regulating or controlling combustion. 1,763 US utility patents granted 2015–2025, with the leading assignees and year-by-year filing trajectory.

1,763
US patents granted
F23
Parent CPC class
20
Active assignees
+5%
5-yr velocity

The verdict

Regulating OR Controlling Combustion ranks #385 of 670 CPC technology areas - 1,763 US patents granted since 2015, with filing up 5% over five years.

#385
of 670 CPC technology areas
1,763
US patents granted, 2015–2025
General Electric
leading assignee (89)
+5%
filing velocity, last 5 yrs
Top assignee: General Electric Company (89 patents)

CPC subclass F23N - REGULATING OR CONTROLLING COMBUSTION - covers 1,763 US utility patents granted between 2015 and 2025 according to USPTO PatentsView records, within the broader CPC class F23 (COMBUSTION APPARATUS; COMBUSTION PROCESSES). See our CPC classification guide for how the system works.

The competitive landscape in F23N is shaped by 20 distinct companies actively filing in this space. General Electric Company leads with 89 patents, followed by Haier US Appliance Solutions, Inc. at 38 grants and Emerson Electric Co. at 26.

Filing activity in F23N is up 5% 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 F23N innovation accelerating?

US utility-patent grants per year in F23N, 2015–2025 - recent five years are up 5% versus 2015–2019.

50100150200250 20152016201720182019202020212022202320242025 103

Who leads F23N?

The 12 most active assignees in REGULATING OR CONTROLLING COMBUSTION - wider bars mean more grants

patents

What this shows General Electric is the most active filer in F23N, holding 89 of the 1,763 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 F23N
Rank Company Patents in F23N
#1 Clearsign Combustion Corporation 40
#2 Haier US Appliance Solutions, Inc. 38
#3 Emerson Electric Co. 26
#4 Midea Group Co., Ltd. 23
#5 Rheem Manufacturing Company 23
#6 Kyungdong Navien Co., Ltd. 20
#7 Rinnai Corporation 20
#8 Grand Mate Co., Ltd. 20
#9 Weber-stephen Products Llc 19
#10 Eberspächer Climate Control Systems Gmbh 18
#11 Copreci, S.coop. 16
#12 Azbil Corporation 15
#13 Clearsign Technologies Corporation 15
#14 Noritz Corporation 14
#15 Ener-core Power, Inc. 12
#16 Ademco Inc. 11
#17 SIT S.p.a. 11
#18 Delavan Inc. 10
#19 A. O. Smith Corporation 10
#20 Copeland Comfort Control Lp 10

About This Class

CPC subclass F23N belongs to class F23.

1,763 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 F23N 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 F23N assignees by class footprint. Bubble size = patents in F23N. Source: USPTO PatentsView (claim depth is company-wide across all classes).

Top 14 F23N assignees by class footprint. Bubble size = patents in F23N. Source: USPTO PatentsView (claim depth is company-wide across all classes). Scatter plot of 14 data points (bubble-sized by third dimension). 010203040 1020304050 Patents in F23N Avg claims / patent (company-wide) Clearsign CombustionHaier Us Appliance So…Emerson ElectricMidea GroupRheem ManufacturingKyungdong NavienRinnaiGrand MateWeber-stephen ProductsEberspÄCher Climate C…Copreci S CoopAzbilClearsignNoritz
Top 14 F23N assignees by class footprint. Bubble size = patents in F23N. Source: USPTO PatentsView (claim depth is company-wide across all classes).

Frequently Asked Questions

What is CPC class F23N?
CPC subclass F23N covers REGULATING OR CONTROLLING COMBUSTION. It belongs to CPC class F23 (COMBUSTION APPARATUS; COMBUSTION PROCESSES), with 1,763 US utility patents granted since 2015.
How many patents have been filed in F23N?
1,763 US utility patents were granted in CPC subclass F23N between 2015 and 2025, based on USPTO PatentsView data.
Which company holds the most patents in F23N?
General Electric Company leads F23N with 89 patents, making it the most active assignee in this technology area.
How is patent data for F23N 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., F23) is a broad technology category. Subclasses like F23N 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.