Nelson Industries, Inc.

Digisonix, Inc.

Fleetguard, Inc.

Universal Silencer, LLC

Cary D Bremigan

Larry J Eriksson

C Raymond Cheng

Z Gerald Liu

Mark C Allie

Michael T Zuroski

Mark P Adams

Patrick Klein

Kenneth J Kicinski

David Kapsos

An exhaust aftertreatment system, including injection of chemical species, includes a mixer provided by a spiral chamber.

Exhaust aftertreatment system with spiral mixer

An exhaust aftertreatment device ( ) includes an aftertreatment element ( ) for treating internal combustion engine exhaust, an injector ( ) for injecting chemical species mixing with the exhaust prior to reaching the aftertreatment element, and a turbulator ( ) turbulating the exhaust to enhance the noted mixing. In a desired combination, a two-stage integrated perforated tube combination structure includes a turbulent mixing tube ( ) disposed in an acoustic tube ( ) and concentrically surrounded thereby.

Exhaust aftertreatment device, including chemical mixing and acoustic effects

An active silencer for a vehicle exhaust system that is constructed so that it can be hung underneath the vehicle without altering the vehicle. The silencer has a chamber isolated from the exhaust flow. A duct spans longitudinally through the chamber. One or more loudspeakers (e.g. 2 or 4 loudspeakers) are mounted on the duct side-by-side. The loudspeakers share a common tuning volume within the duct which is ported to a mixing apparatus where the canceling acoustic wave mixes with noise from the exhaust flow before the exhaust noise exits to the atmosphere.

Active exhaust silencer

A multi-channel communication system is provided. In an active acoustic attenuation implementation, noise, including cross-coupled noise between channels and locations, designated audio signals, and echoes, are canceled, but not speech from another location. A particularly desirable vehicle application is provided.

Multi-channel communication system

An active acoustic attenuation system specifies the error signal (44) to correspondingly specify the output acoustic wave. In the preferred embodiment, the error signal (44) is specified by summing (210) the error signal (44) with a desired signal (204) to provide a specified error signal (206) to the error input (202) of the adaptive filter model (40) such that the model (40) outputs the correction signal (46) to the output transducer (14) to introduce the canceling acoustic wave which specifies the output acoustic wave such that a desired signal is present in the output acoustic wave.

Active attenuation system with specified output acoustic wave

Active acoustic attenuation apparatus is provided for cancellation of noise from an exhaust pipe (12). A chamber (50) has an input (70) receiving exhaust from the exhaust pipe and directing the exhaust along a flowpath (76) to a chamber output (74). Speakers (88, 90) are transversely spaced and offset from the flowpath and introduce sound into the chamber at a space (56) having a transverse area at least as large as each speaker, to minimize acoustic loading of the speakers and to protect the speakers from the heat of hot exhaust for automotive applications, including electronic mufflers.

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Madison, WI, United States of America

Cary D Bremigan