CPC technology class · F04

F04C - Rotary-piston

Rotary-piston, or oscillating-piston, positive-displacement machines for liquids ; rotary-piston, or oscillating-piston, positive-displacement pumps. 6,508 US utility patents granted 2015–2025, with the leading assignees and year-by-year grant trajectory.

Compiled by PlainPatent · May 15, 2026

6,508
US patents granted: #3/4
in F04: 18.5%
F04 class share: -6%
5-yr velocity

The verdict

According to USPTO PatentsView, Rotary-piston ranks #219 of 670 CPC technology areas - 6,508 US patents granted since 2015, with recorded grant volume down 6% over five years.

#219
of 670 CPC technology areas: 6,508
US patents granted, 2015–2025: Lg
leading assignee (313): -6%
grant velocity, last 5 yrs

How F04C's grant cadence moved

Between 2020–2024, F04C recorded 2,913 grants versus 3,088 in 2015–2019 (-6% equal-window velocity). Across complete years, output peaked in 2018 at 667 grants and bottomed in 2023 at 517 (+29% peak-over-trough). Lead assignee Emerson Climate Technologies, Inc. holds 2.9% of the class ; the top three share 7.6%.

Leaderboard read

F04C concentration, lead at 2.9%

Emerson Climate Technologies, Inc. leads this historical grant record at 2.9% of F04C - foreign corporation assignees hold 65% of class grants (2,349 of 3,603). Figures describe granted US utility patents in this CPC subclass, not current investment or legal strength.

Leader's share: 2.9%
Top three share: 7.6%
Lead over #2: 25

Where F04C sits inside F04

Among 4 subclasses in F04 (Positive - Displacement Machines FOR LIQUIDS; Pumps FOR Liquids OR Elastic Fluids), F04C ranks #3 and holds 18.5% of the parent class's 35,173 recorded grants. Sibling chips below are the other subclasses in the same parent class, not the nationwide volume/lead-share peers further down.

F04D 16,174 F04B 11,585 F04F 906

Rising assignees active in F04C

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 Copeland LP 47x 0 → 47 company-wide · 27 in F04C
#2 Copeland Climate Technologies (Suzhou) Co. Ltd. 15x 0 → 15 company-wide · 15 in F04C
#3 Elivac Co., Ltd. 7.00x 0 → 7 company-wide · 8 in F04C
#4 Leistritz Pumpen GMBH 6.00x 2 → 12 company-wide · 15 in F04C
#5 Copeland Europe GmbH 6.00x 0 → 6 company-wide · 5 in F04C

F04C grants by year, peak 2018 (667)

US utility-patent grants per year in F04C, 2015–2025 - recent five years are down 6% versus 2015–2019.

Emerson Climate

188
Daikin Industries

163
Toyota Jidoshokki

143
Hitachi Industrial…

101
Deka Products…

100
Atlas Copco Airpower…

90
Hanon Systems

82
Trane International

79
Edwards

71
Bitzer Kühlmaschinenba…

55
Mitsubishi Heavy…

52
Fujitsu General

47

What this shows Lg is the most active filer in F04C, holding 313 of the 6,508 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 F04C
Rank	Company	Patents in F04C
#1	Emerson Climate Technologies, Inc.	188
#2	Daikin Industries, Ltd.	163
#3	Kabushiki Kaisha Toyota Jidoshokki	143
#4	Hitachi Industrial Equipment Systems Co., Ltd.	101
#5	Deka Products Limited Parternship	100
#6	Atlas Copco Airpower, Naamloze Vennootschap	90
#7	Hanon Systems	82
#8	Trane International Inc.	79
#9	Edwards Limited	71
#10	Bitzer Kühlmaschinenbau GmbH	55
#11	Mitsubishi Heavy Industries Thermal Systems, Ltd.	52
#12	Fujitsu General Limited	47
#13	Gree Electric Appliances, Inc. OF Zhuhai	44
#14	Schwäbische Hüttenwerke Automotive GmbH	42
#15	Covidien LP	41
#16	Danfoss Commercial Compressors	39
#17	Pierburg Pump Technology GMBH	37
#18	Kobe Steel Ltd.	36
#19	Aerin Medical Inc.	36
#20	Ingersoll-Rand Industrial U.S., Inc.	35

Footprint here vs. claim strategy

Each dot is a leading F04C 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 F04C assignees by class footprint. Bubble size = patents in F04C. Source: USPTO PatentsView (claim depth is company-wide across all classes).

Classes near F04C's 6,508-grant footprint

Nationwide nearest neighbors for F04C (#219 of 670 by volume ; lead share 4.8%) - not the F04 parent-class siblings above.

Nearest by grant volume

C11D 6,504 G01T 6,488 H02S 6,483 C07H 6,464

Nearest by lead-assignee share

F16D 4.8% B60M 4.8% B22F 4.8% F16H 4.8%

Questions about F04C

Which company holds the most patents in F04C?

LG Electronics Inc. leads F04C with 313 patents (2.9% of the subclass). By PatentsView assignee type, foreign corporations account for 65% of class grants.

Which F04C assignees grew fastest recently?

Among assignees with ≥5 grants in F04C, Copeland LP shows the highest company-wide grant multiple (47x: 0 grants in 2019–2021 → 47 in 2022–2024) while holding 27 patents in this subclass. Growth is company-wide, not class-only.

How does F04C compare inside parent class F04?

Inside F04 (Positive - Displacement Machines FOR LIQUIDS; Pumps FOR Liquids OR Elastic Fluids), F04C ranks #3 of 4 subclasses by grant volume and holds 18.5% of the parent class total. The largest sibling is F04D (16,174 grants).

What to do with this data

F04C in context - here's where to go next.

Emerson Climate Technologies, Inc. leads F04C with 188 grants in this class. See full portfolio
F04C ranks #219 of 670 by grant volume among all tracked CPC technology areas. See the ranking
Inside parent class F04, the largest sibling subclass is F04D with 16,174 grants. Explore F04D

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

Methodology - F04C figures are USPTO PatentsView granted-utility totals for this subclass (6,508 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.