What is CPC F04C29/065?

CPC F04C29/065 is the Cooperative Patent Classification code for “Noise dampening volumes, e.g. muffler chambers.”

How many patents are filed under CPC F04C29/065 (Noise dampening volumes, e.g. muffler chambers)?

Our database includes 214 publications tagged with this CPC code.

Publication counts under this code: 23 in 2024 vs 13 in 2025 (latest complete years).

Noise dampening volumes, e.g. muffler chambers · Cooperative Patent Classification (CPC)

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

Mapped technology topics for this CPC code.

CPC classification statistics
Metric	Value
CPC code	F04C29/065
Official title	{Noise dampening volumes, e.g. muffler chambers}
Display label	Noise dampening volumes, e.g. muffler chambers
Total patents	214

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

Filing activity over the last five years is declining.

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

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

What is CPC F04C29/065?: CPC F04C29/065 is the Cooperative Patent Classification code for “Noise dampening volumes, e.g. muffler chambers.”
How many patents are filed under CPC F04C29/065 (Noise dampening volumes, e.g. muffler chambers)?: Our database includes 214 publications tagged with this CPC code.
Is patent activity under CPC F04C29/065 growing?: Publication counts under this code: 23 in 2024 vs 13 in 2025 (latest complete years).