Centrifugal fan with dual outlets in the same direction and fan frame thereof
US-2016369811-A1 · Dec 22, 2016 · US
Sound attenuation
Sound attenuation · Cooperative Patent Classification (CPC)
Engines, pumps, lighting, heating, and mechanical systems.
Related technology areas
Mapped technology topics for this CPC code.
| Metric | Value |
|---|---|
| CPC code | F04D29/663 |
| Official title | {Sound attenuation} |
| Display label | Sound attenuation |
| Total patents | 607 |
Filing trend
Year-over-year patent counts classified under this CPC code.
Filing activity over the last five years is stable.
| Year | Patents |
|---|---|
| 2015 | 36 |
| 2016 | 41 |
| 2017 | 44 |
| 2018 | 73 |
| 2019 | 86 |
| 2020 | 55 |
| 2021 | 53 |
| 2022 | 51 |
| 2023 | 56 |
| 2024 | 57 |
| 2025 | 50 |
| 2026 | 5 |
Representative patents
Representative publications under this CPC code from precomputed stats, or recent filings when stats are unavailable.
Method of retaining a noise attenuation device in a compressor cover
US-2016363136-A1 · Dec 15, 2016 · US
Multiple stage blowers and volutes therefor
US-2016339193-A1 · Nov 24, 2016 · US
Multiple stage blowers and volutes therefor
US-2016333885-A1 · Nov 17, 2016 · US
Blower device and respirator including blower device
US-2016312801-A1 · Oct 27, 2016 · US
Blower and outdoor unit of air conditioner comprising same
US-2016305452-A1 · Oct 20, 2016 · US
Modal noise reduction for gas turbine engine
US-2016298651-A1 · Oct 13, 2016 · US
Centrifugal fan
US-2016281731-A1 · Sep 29, 2016 · US
Noise attenuation device for compressor inlet duct
US-2016258447-A1 · Sep 8, 2016 · US
Multiple stage blowers and volutes therefor
US-9427538-B2 · Aug 30, 2016 · US
Centrifugal fan and air conditioner provided with the same
US-2016245298-A1 · Aug 25, 2016 · US
Acoustic Resonator Assembly Having Variable Degrees of Freedom
US-2016230778-A1 · Aug 11, 2016 · US
Hair dryer
US-2016213122-A1 · Jul 28, 2016 · US
Blower assembly for a vehicle
US-2016208816-A1 · Jul 21, 2016 · US
Suction device with sound mirror device
US-2016201691-A1 · Jul 14, 2016 · US
Centrifugal fan, and fan equipped with sound-muffling box and using centrifugal fan
US-2016195106-A1 · Jul 7, 2016 · US
Blower apparatus
US-2016169249-A1 · Jun 16, 2016 · US
Fan shroud assembly
US-2016138610-A1 · May 19, 2016 · US
Turbocharger compressor noise reduction system and method
US-9303561-B2 · Apr 5, 2016 · US
Acoustic baffle for centrifugal blowers
US-9279358-B2 · Mar 8, 2016 · US
Frequently asked questions
Answers are generated from the same data shown on this page.
- What is CPC F04D29/663?
- CPC F04D29/663 is the Cooperative Patent Classification code for “Sound attenuation.”
- How many patents are filed under CPC F04D29/663 (Sound attenuation)?
- Our database includes 607 publications tagged with this CPC code.
- Is patent activity under CPC F04D29/663 growing?
- Publication counts under this code: 57 in 2024 vs 50 in 2025 (latest complete years).