PlainPatent

CPC technology class · B61

B61F - RAIL Vehicle Suspensions

Rail vehicle suspensions, e.g. underframes, bogies or arrangements of wheel axles; rail vehicles for use on tracks of different width; preventing derailing of rail vehicles; wheel guards, obstruction removers or the like for rail vehicles. 797 US utility patents granted 2015–2025, with the leading assignees and year-by-year filing trajectory.

797
US patents granted
B61
Parent CPC class
20
Active assignees
+21%
5-yr velocity

The verdict

RAIL Vehicle Suspensions ranks #482 of 670 CPC technology areas - 797 US patents granted since 2015, with filing up 21% over five years.

#482
of 670 CPC technology areas
797
US patents granted, 2015–2025
Kawasaki Jukogyo
leading assignee (93)
+21%
filing velocity, last 5 yrs
Top assignee: Kawasaki Jukogyo Kabushiki Kaisha (93 patents)

CPC subclass B61F - RAIL VEHICLE SUSPENSIONS, e.g. UNDERFRAMES, BOGIES OR ARRANGEMENTS OF WHEEL AXLES; RAIL VEHICLES FOR USE ON TRACKS OF DIFFERENT WIDTH; PREVENTING DERAILING OF RAIL VEHICLES; WHEEL GUARDS, OBSTRUCTION REMOVERS OR THE LIKE FOR RAIL VEHICLES - covers 797 US utility patents granted between 2015 and 2025 according to USPTO PatentsView records, within the broader CPC class B61 (RAILWAYS). See our CPC classification guide for how the system works.

The competitive landscape in B61F is shaped by 20 distinct companies actively filing in this space. Kawasaki Jukogyo Kabushiki Kaisha leads with 93 patents, followed by Bombardier Transportation Gmbh at 32 grants and CRRC Qingdao Sifang Co., Ltd. at 31.

Filing activity in B61F is up 21% over the past five years versus 2015-2019, a sharp acceleration suggesting an emerging or fast-moving technology area. All counts come directly from USPTO PatentsView and reflect US granted utility patents only.

Is B61F innovation accelerating?

US utility-patent grants per year in B61F, 2015–2025 - recent five years are up 21% versus 2015–2019.

20406080100 20152016201720182019202020212022202320242025 34

Who leads B61F?

The 12 most active assignees in RAIL VEHICLE SUSPENSIONS, e.g. UNDERFRAMES, BOGIES OR ARRANGEMENTS OF WHEEL AXLES; RAIL VEHICLES FOR USE ON TRACKS OF DIFFERENT WIDTH; PREVENTING DERAILING OF RAIL VEHICLES; WHEEL GUARDS, OBSTRUCTION REMOVERS OR THE LIKE FOR RAIL VEHICLES - wider bars mean more grants

patents

What this shows Kawasaki Jukogyo is the most active filer in B61F, holding 93 of the 797 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 B61F
Rank Company Patents in B61F
#1 Kawasaki Jukogyo Kabushiki Kaisha 93
#2 Bombardier Transportation Gmbh 32
#3 CRRC Qingdao Sifang Co., Ltd. 31
#4 Amsted Rail Company, Inc. 28
#5 Siemens Mobility Gmbh 26
#6 Alstom Transport Technologies 25
#7 Nevis Industries Llc 23
#8 Siemens Mobility Austria Gmbh 21
#9 National Steel Car Limited 15
#10 KYB Corporation 14
#11 Siemens Ag Österreich 13
#12 Nippon Sharyo, Ltd. 11
#13 CRRC Tangshan Co., Ltd. 11
#14 Kawasaki Railcar Manufacturing Co., Ltd. 10
#15 Firestone Industrial Products Company, Llc 9
#16 Standard CAR Truck Company 9
#17 Mitsubishi Heavy Industries Engineering, Ltd. 8
#18 Electro-motive Diesel, Inc. 6
#19 Knorr-bremse Systeme Für Schienenfahrzeuge Gmbh 6
#20 Trinity RAIL Group, Llc 6

About This Class

CPC subclass B61F belongs to class B61.

797 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 B61F 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 B61F assignees by class footprint. Bubble size = patents in B61F. Source: USPTO PatentsView (claim depth is company-wide across all classes).

Top 14 B61F assignees by class footprint. Bubble size = patents in B61F. Source: USPTO PatentsView (claim depth is company-wide across all classes). Scatter plot of 14 data points (bubble-sized by third dimension). 051015202530 020406080100 Patents in B61F Avg claims / patent (company-wide) Kawasaki JukogyoBombardier Transporta…Crrc Qingdao SifangAmsted RailSiemens MobilityAlstom TransportNevis IndustriesSiemens Mobility Aust…National Steel CarKybSiemens ÖsterreichNippon SharyoCrrc TangshanKawasaki Railcar Manu…
Top 14 B61F assignees by class footprint. Bubble size = patents in B61F. Source: USPTO PatentsView (claim depth is company-wide across all classes).

Frequently Asked Questions

What is CPC class B61F?
CPC subclass B61F covers RAIL VEHICLE SUSPENSIONS, e.g. UNDERFRAMES, BOGIES OR ARRANGEMENTS OF WHEEL AXLES; RAIL VEHICLES FOR USE ON TRACKS OF DIFFERENT WIDTH; PREVENTING DERAILING OF RAIL VEHICLES; WHEEL GUARDS, OBSTRUCTION REMOVERS OR THE LIKE FOR RAIL VEHICLES. It belongs to CPC class B61 (RAILWAYS), with 797 US utility patents granted since 2015.
How many patents have been filed in B61F?
797 US utility patents were granted in CPC subclass B61F between 2015 and 2025, based on USPTO PatentsView data.
Which company holds the most patents in B61F?
Kawasaki Jukogyo Kabushiki Kaisha leads B61F with 93 patents, making it the most active assignee in this technology area.
How is patent data for B61F 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., B61) is a broad technology category. Subclasses like B61F 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.