CPC technology class · F23

F23B - Methods Or Apparatus For Combustion Using Only Solid Fuel

Methods or apparatus for combustion using only solid fuel. 220 US utility patents granted 2015–2025, with the leading assignees and year-by-year grant trajectory.

Compiled by PlainPatent · May 15, 2026

220
US patents granted: #11/12
in F23: 1.4%
F23 class share: +33%
5-yr velocity

The verdict

According to USPTO PatentsView, Methods Or Apparatus For Combustion Using Only Solid Fuel ranks #596 of 670 CPC technology areas - 220 US patents granted since 2015, with recorded grant volume up 33% over five years.

#596
of 670 CPC technology areas: 220
US patents granted, 2015–2025: Weber-stephen Products
leading assignee (9): +33%
grant velocity, last 5 yrs

How F23B's grant cadence moved

Between 2020–2024, F23B recorded 114 grants versus 86 in 2015–2019 (+33% equal-window velocity). Across complete years, output peaked in 2024 at 27 grants and bottomed in 2015 at 11 (+145% peak-over-trough). Lead assignee Weber-Stephen Products LLC holds 4.1% of the class ; the top three share 10.5%.

Leaderboard read

F23B concentration, lead at 4.1%

Weber-Stephen Products LLC leads this historical grant record at 4.1% of F23B - us corporation assignees hold 80% of class grants (78 of 98). Figures describe granted US utility patents in this CPC subclass, not current investment or legal strength.

Leader's share: 4.1%
Top three share: 10.5%
Lead over #2: 0

Where F23B sits inside F23

Among 12 subclasses in F23 (Combustion APPARATUS; Combustion Processes), F23B ranks #11 and holds 1.4% of the parent class's 15,279 recorded grants. Sibling chips below are the other subclasses in the same parent class, not the nationwide volume/lead-share peers further down.

F23R 4,138 F23D 2,623 F23N 1,763 F23C 1,571 F23J 1,082 F23G 1,073 F23L 922 F23K 754

Rising assignees active in F23B

Company-wide grant multiples (2022–2024 vs 2019–2021) among assignees with ≥5 patents in this subclass. Growth is company-wide; class patent counts are subclass-specific.

#1 Weber-Stephen Products LLC 1.64x 52 → 85 company-wide · 9 in F23B
#2 W.C. Bradley Co. 0.92x 12 → 11 company-wide · 5 in F23B
#3 Clearsign Combustion Corporation 0.05x 19 → 1 company-wide · 9 in F23B

F23B grants by year, peak 2024 (27)

US utility-patent grants per year in F23B, 2015–2025 - recent five years are up 33% versus 2015–2019.

Weber-stephen Products

9
Clearsign Combustion

9
W C Bradley

5
Biochar Now

5
Traeger Pellet Grills

4
Biomass Controls

4
Solo Brands

3
Dansons Us

3
Maxitrol

3
United States Stove

3
Qingdao Genjoy Home…

3
Jupiter Oxygen

3

What this shows Weber-stephen Products is the most active filer in F23B, holding 9 of the 220 patents in this class. Concentration at the top signals how contestable this technology area is for new entrants.

View data table

Top patent holders in CPC subclass F23B
Rank	Company	Patents in F23B
#1	Weber-Stephen Products LLC	9
#2	Clearsign Combustion Corporation	9
#3	W.C. Bradley Co.	5
#4	Biochar Now, LLC	5
#5	Traeger Pellet Grills, LLC	4
#6	Biomass Controls, LLC	4
#7	Solo Brands, LLC	3
#8	Dansons US, LLC	3
#9	Maxitrol Company	3
#10	United States Stove Company	3
#11	Qingdao Genjoy Home Fashion Co., Ltd.	3
#12	Jupiter Oxygen Corporation	3
#13	North Atlantic Imports, LLC	2
#14	Royal Melbourne Institute OF Technology	2
#15	Alexza Pharmaceuticals, Inc.	2
#16	The Cashmere Caveman Co, Wild Kitchens Limited	2
#17	Sierra Space Corporation	2
#18	BioLite, Inc.	2
#19	Martin GmbH für Umwelt- und Energietechik	2
#20	Onward Multi-Corp. Inc.	2

Footprint here vs. claim strategy

Each dot is a leading F23B 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 F23B assignees by class footprint. Bubble size = patents in F23B. Source: USPTO PatentsView (claim depth is company-wide across all classes).

Questions about F23B

Which company holds the most patents in F23B?

Weber-Stephen Products LLC leads F23B with 9 patents (4.1% of the subclass). By PatentsView assignee type, us corporations account for 80% of class grants.

Which F23B assignees grew fastest recently?

Among assignees with ≥5 grants in F23B, Weber-Stephen Products LLC shows the highest company-wide grant multiple (1.64x: 52 grants in 2019–2021 → 85 in 2022–2024) while holding 9 patents in this subclass. Growth is company-wide, not class-only.

How does F23B compare inside parent class F23?

Inside F23 (Combustion APPARATUS; Combustion Processes), F23B ranks #11 of 12 subclasses by grant volume and holds 1.4% of the parent class total. The largest sibling is F23R (4,138 grants).

What to do with this data

F23B in context - here's where to go next.

Weber-Stephen Products LLC leads F23B with 9 grants in this class. See full portfolio
F23B ranks #596 of 670 by grant volume among all tracked CPC technology areas. See the ranking
Inside parent class F23, the largest sibling subclass is F23R with 4,138 grants. Explore F23R

Figures reflect USPTO PatentsView grant data through 2026-05-15; pending applications not yet granted are not counted.

Methodology - F23B figures are USPTO PatentsView granted-utility totals for this subclass (220 grants in the tracked window).

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.