PlainPatent

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 filing trajectory.

6,508
US patents granted
F04
Parent CPC class
20
Active assignees
+6%
5-yr velocity

The verdict

Rotary-piston ranks #219 of 670 CPC technology areas - 6,508 US patents granted since 2015, with filing up 6% over five years.

#219
of 670 CPC technology areas
6,508
US patents granted, 2015–2025
Lg
leading assignee (313)
+6%
filing velocity, last 5 yrs
Top assignee: LG Electronics Inc. (313 patents)

CPC subclass F04C - ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS ; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS - covers 6,508 US utility patents granted between 2015 and 2025 according to USPTO PatentsView records, within the broader CPC class F04 (POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS). See our CPC classification guide for how the system works.

The competitive landscape in F04C is shaped by 20 distinct companies actively filing in this space. LG Electronics Inc. leads with 313 patents, followed by Daikin Industries, Ltd. at 163 grants and Kabushiki Kaisha Toyota Jidoshokki at 143.

Filing activity in F04C is up 6% 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 F04C innovation accelerating?

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

300400500600700 20152016201720182019202020212022202320242025 353

Who leads F04C?

The 12 most active assignees in ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS ; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS - wider bars mean more grants

patents

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.

Source USPTO PatentsView, granted utility patents As of 2015–2025 grant years
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

About This Class

CPC subclass F04C belongs to class F04.

6,508 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 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).

Top 14 F04C assignees by class footprint. Bubble size = patents in F04C. Source: USPTO PatentsView (claim depth is company-wide across all classes). Scatter plot of 14 data points (bubble-sized by third dimension). 0510152025 050100150200 Patents in F04C Avg claims / patent (company-wide) Emerson ClimateDaikin IndustriesToyota JidoshokkiHitachi Industrial Eq…Deka Products Partern…Atlas Copco Airpower…Hanon SystemsTrane InternationalEdwardsBitzer Kühlmaschinenb…Mitsubishi Heavy Indu…Fujitsu GeneralGree Electric Applian…Schwäbische Hüttenwer…
Top 14 F04C assignees by class footprint. Bubble size = patents in F04C. Source: USPTO PatentsView (claim depth is company-wide across all classes).

Frequently Asked Questions

What is CPC class F04C?
CPC subclass F04C covers ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS ; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS. It belongs to CPC class F04 (POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS), with 6,508 US utility patents granted since 2015.
How many patents have been filed in F04C?
6,508 US utility patents were granted in CPC subclass F04C between 2015 and 2025, based on USPTO PatentsView data.
Which company holds the most patents in F04C?
LG Electronics Inc. leads F04C with 313 patents, making it the most active assignee in this technology area.
How is patent data for F04C 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., F04) is a broad technology category. Subclasses like F04C 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.