What is CPC F04B3/00?

CPC F04B3/00 is the Cooperative Patent Classification code for “Machines or pumps with pistons coacting within one cylinder, e.g. multi-stage.”

How many patents are filed under CPC F04B3/00 (Machines or pumps with pistons coacting within one cylinder, e.g. multi-stage)?

Our database includes 38 publications tagged with this CPC code.

Is patent activity under CPC F04B3/00 growing?

Publication counts under this code: 2 in 2023 vs 4 in 2025 (latest complete years).

Machines or pumps with pistons coacting within one cylinder, e.g. multi-stage

Machines or pumps with pistons coacting within one cylinder, e.g. multi-stage · Cooperative Patent Classification (CPC)

Engines, pumps, lighting, heating, and mechanical systems.

Related technology areas

Mapped technology topics for this CPC code.

Mechanical Engineering

CPC classification statistics
Metric	Value
CPC code	F04B3/00
Official title	Machines or pumps with pistons coacting within one cylinder, e.g. multi-stage
Display label	Machines or pumps with pistons coacting within one cylinder, e.g. multi-stage
Total patents	38

Filing trend

Year-over-year patent counts classified under this CPC code.

Filing activity over the last five years is declining.

Patents filed per year
Year	Patents
2015	7
2016	2
2017	3
2018	9
2019	4
2020	6
2023	2
2025	4
2026	1

Representative patents

Representative publications under this CPC code from precomputed stats, or recent filings when stats are unavailable.

Fluid compression apparatus and method
US-12553421-B2 · Feb 17, 2026 · US
Fluid compression apparatus and method
US-12486835-B2 · Dec 2, 2025 · US
Fluid compression apparatus and method
US-2025237201-A1 · Jul 24, 2025 · US
Fluid compression apparatus and method
US-2025237205-A1 · Jul 24, 2025 · US
Compression apparatus and filling station comprising such an apparatus
US-12188461-B2 · Jan 7, 2025 · US
Compression apparatus and filling station comprising such an apparatus
US-2023085780-A1 · Mar 23, 2023 · US
Compression apparatus and filling station comprising such an apparatus
US-2023080231-A1 · Mar 16, 2023 · US
Dual-stage pump with switching valve
US-10851909-B2 · Dec 1, 2020 · US
Push-pull compressor having ultra-high efficiency for cryocoolers or other systems
US-10738772-B2 · Aug 11, 2020 · US
Liquid supply system
US-2020232448-A1 · Jul 23, 2020 · US
Reciprocation pump and a dialysis apparatus equipped with the reciprocation pump
US-10612533-B2 · Apr 7, 2020 · US
Method of priming a medical pump
US-10610637-B2 · Apr 7, 2020 · US
Liquid supply system
US-2020011322-A1 · Jan 9, 2020 · US
Push-pull compressor having ultra-high efficiency for cryocoolers or other systems
US-2019368480-A1 · Dec 5, 2019 · US
Push-pull compressor having ultra-high efficiency for cryocoolers or other systems
US-10422329-B2 · Sep 24, 2019 · US
Hybrid opposed-piston engine system
US-10329996-B2 · Jun 25, 2019 · US
Push-pull compressor having ultra-high efficiency for cryocoolers or other systems
US-2019048863-A1 · Feb 14, 2019 · US
Electromagnetic actuator for a reciprocating compressor
US-10030638-B2 · Jul 24, 2018 · US
Dual-stage pump with switching valve
US-2018195510-A1 · Jul 12, 2018 · US
Plural component proportioner
US-2018135608-A1 · May 17, 2018 · US

Frequently asked questions

Answers are generated from the same data shown on this page.

What is CPC F04B3/00?: CPC F04B3/00 is the Cooperative Patent Classification code for “Machines or pumps with pistons coacting within one cylinder, e.g. multi-stage.”
How many patents are filed under CPC F04B3/00 (Machines or pumps with pistons coacting within one cylinder, e.g. multi-stage)?: Our database includes 38 publications tagged with this CPC code.
Is patent activity under CPC F04B3/00 growing?: Publication counts under this code: 2 in 2023 vs 4 in 2025 (latest complete years).