PlainPatent

CPC technology class · F03

F03G - Spring

Spring, weight, inertia or like motors; mechanical-power producing devices or mechanisms, not otherwise provided for or using energy sources not otherwise provided for. 2,252 US utility patents granted 2015–2025, with the leading assignees and year-by-year grant trajectory.

2,252
US patents granted
#2/5
in F03
18.9%
F03 class share
+9%
5-yr velocity

The verdict

According to USPTO PatentsView, Spring ranks #357 of 670 CPC technology areas - 2,252 US patents granted since 2015, with recorded grant volume up 9% over five years.

#357
of 670 CPC technology areas
2,252
US patents granted, 2015–2025
Cambridge Mechatronics
leading assignee (54)
+9%
grant velocity, last 5 yrs

How F03G's grant cadence moved

Between 2020–2024, F03G recorded 1,008 grants versus 928 in 2015–2019 (+9% equal-window velocity). Across complete years, output peaked in 2023 at 224 grants and bottomed in 2020 at 160 (+40% peak-over-trough). Lead assignee Cambridge Mechatronics Limited holds 2.4% of the class ; the top three share 6.1%.

Leaderboard read

F03G concentration, lead at 2.4%

Cambridge Mechatronics Limited leads this historical grant record at 2.4% of F03G - us corporation assignees hold 52% of class grants (376 of 730). Figures describe granted US utility patents in this CPC subclass, not current investment or legal strength.

Leader's share
2.4%

54 of 2,252 grants

Top three share
6.1%

of the class's recorded grants

Lead over #2
11

more grants than ICE Thermal Harvesting, LLC

Where F03G sits inside F03

Among 5 subclasses in F03 (Machines OR Engines FOR LIQUIDS; Wind, Spring, OR Weight MOTORS; Producing Mechanical Power OR A Reactive Propulsive Thrust, NOT Otherwise Provided FOR), F03G ranks #2 and holds 18.9% of the parent class's 11,891 recorded grants. Sibling chips below are the other subclasses in the same parent class, not the nationwide volume/lead-share peers further down.

F03D 7,370 F03B 1,544 F03C 404 F03H 321

Rising assignees active in F03G

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. #1 ICE Thermal Harvesting, LLC 45x 1 → 45 company-wide · 43 in F03G
  2. #2 Rondo Energy, Inc. 36x 0 → 36 company-wide · 41 in F03G
  3. #3 EnhancedGEO Holdings, LLC 12x 0 → 12 company-wide · 7 in F03G
  4. #4 Energy Vault, Inc. 5.25x 4 → 21 company-wide · 23 in F03G
  5. #5 Norwich Technologies, Inc. 5.00x 1 → 5 company-wide · 5 in F03G

F03G grants by year, peak 2023 (224)

US utility-patent grants per year in F03G, 2015–2025 - recent five years are up 9% versus 2015–2019.

140160180200220240 20152016201720182019202020212022202320242025 196

Who leads F03G?

The 12 most active assignees in Spring, Weight, Inertia OR Like MOTORS; Mechanical-power Producing Devices OR Mechanisms, NOT Otherwise Provided FOR OR Using Energy Sources NOT Otherwise Provided FOR - wider bars mean more grants

patents

What this shows Cambridge Mechatronics is the most active filer in F03G, holding 54 of the 2,252 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 F03G
Rank Company Patents in F03G
#1 Cambridge Mechatronics Limited 54
#2 ICE Thermal Harvesting, LLC 43
#3 Rondo Energy, Inc. 41
#4 TDK Taiwan Corp. 38
#5 Hutchinson Technology Incorporated 30
#6 Energy Vault, Inc. 23
#7 ClearMotion, Inc. 19
#8 Lintec OF America, Inc. 17
#9 Exergyn, Ltd. 17
#10 The Abell Foundation, Inc. 15
#11 Saes Getters S.P.A. 11
#12 Ormat Technologies Inc. 11
#13 Qwtip LLC 11
#14 Aperia Technologies, Inc. 10
#15 Actuator Solutions GMBH 9
#16 Eavor Technologies Inc. 8
#17 EnhancedGEO Holdings, LLC 7
#18 SMR Patents S.à.r.l. 6
#19 Alfmeier PRÄZISION SE 6
#20 Julius Blum GMBH 5

Footprint here vs. claim strategy

Each dot is a leading F03G 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 F03G assignees by class footprint. Bubble size = patents in F03G. Source: USPTO PatentsView (claim depth is company-wide across all classes). Scatter plot of 14 data points (bubble-sized by third dimension). 101520253035 0102030405060 Patents in F03G Avg claims / patent (company-wide) Cambridge MechatronicsIce Thermal HarvestingRondo EnergyTdk TaiwanHutchinson Technology…Energy VaultClearmotionLintec Of AmericaExergynThe Abell FoundationSaes Getters S P AOrmatQwtipAperia
Top 14 F03G assignees by class footprint. Bubble size = patents in F03G. Source: USPTO PatentsView (claim depth is company-wide across all classes).

Classes near F03G's 2,252-grant footprint

Nationwide nearest neighbors for F03G (#357 of 670 by volume ; lead share 2.4%) - not the F03 parent-class siblings above.

Nearest by grant volume

C11B 2,242 B03C 2,224 C40B 2,284 B07C 2,293

Nearest by lead-assignee share

F21W 2.4% G01J 2.4% G05D 2.4% A01G 2.4%

Questions about F03G

Which company holds the most patents in F03G?
Cambridge Mechatronics Limited leads F03G with 54 patents (2.4% of the subclass). By PatentsView assignee type, us corporations account for 52% of class grants.
Which F03G assignees grew fastest recently?
Among assignees with ≥5 grants in F03G, ICE Thermal Harvesting, LLC shows the highest company-wide grant multiple (45x: 1 grants in 2019–2021 → 45 in 2022–2024) while holding 43 patents in this subclass. Growth is company-wide, not class-only.
How does F03G compare inside parent class F03?
Inside F03 (Machines OR Engines FOR LIQUIDS; Wind, Spring, OR Weight MOTORS; Producing Mechanical Power OR A Reactive Propulsive Thrust, NOT Otherwise Provided FOR), F03G ranks #2 of 5 subclasses by grant volume and holds 18.9% of the parent class total. The largest sibling is F03D (7,370 grants).

What to do with this data

F03G in context - here's where to go next.

  • Cambridge Mechatronics Limited leads F03G with 54 grants in this class. See full portfolio
  • F03G ranks #357 of 670 by grant volume among all tracked CPC technology areas. See the ranking
  • Inside parent class F03, the largest sibling subclass is F03D with 7,370 grants. Explore F03D

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

Methodology - F03G figures are USPTO PatentsView granted-utility totals for this subclass (2,252 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.