Patents by Inventor Andre J. De Wachter

Andre J. De Wachter has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5414230
    Abstract: A silencer arrangement for a combustion engine (1) whose exhaust gases are discharged via an exhaust pipe (3) comprises a microphone (9), a tachometer (11) for the engine speed, a control unit (13) and a loudspeaker enclosure (19). The loudspeaker enclosure accommodates two loudspeakers (15, 17) secured to a partition (21). The partition divides the volume of the loudspeaker enclosure into two subvolumes (23, 25). The subvolumes communicate with one another via a tube (27) in order to reduce the electric power required to obtain the desired acoustic power of the sound emitted by the loudspeaker enclosure. One of the subvolumes (25) is acoustically coupled to a tube (33). One end (35) of the tube is situated near the end (7) of the exhaust pipe (3). The sound issuing from the loudspeaker enclosure via the tube interferes with the exhaust-gas sound. A Helmholtz resonator (41) is acoustically coupled to the tube (33) in order to suppress undesired resonances in the tube (33).
    Type: Grant
    Filed: September 17, 1993
    Date of Patent: May 9, 1995
    Assignee: U.S. Philips Corporation
    Inventors: Joris A. M. Nieuwendijk, Johannes W. T. Bax, Andre J. De Wachter