Class 381/165 - By modifying fluid flow

Subclass of Class 381 - Electrical audio signal processing systems and devices
Definition: Subject matter having a source of gas flow which flow interacts
No. of patents: 32
Last issue date: 03/06/2012

Number	Title	Issue Date
8130986	Trapped fluid microsystems for acoustic sensing Silicon and glass micromachined (MEMS) acoustic sensors incorporating trapped-liquid architectures are disclosed. The trapped liquid serves as an acoustic transmission medium allowing the input port to the system to be physically separated from the sensing location....	03/06/2012
7388963	Speaker apparatus A speaker apparatus includes a speaker, and a circuit to operate the speaker. The speaker apparatus further includes a speaker box having an opening to enclose a back of the speaker; a casing accommodating the speaker box combined with the speaker and the circuit th...	06/17/2008
7299894	Acoustic fluid machine An acoustic fluid machine includes an acoustic resonator, a valve device, a piston, and an actuator. The acoustic resonator has a larger-diameter base and a smaller-diameter upper end. The valve device is provided on the upper end of the acoustic resonator and has a...	11/27/2007
7230825	Speaker grill-air vent combinations for a portable computer A system comprising a portable computer chassis having an internal speaker; openings in the chassis from which sound from the speaker can emanate, wherein the openings allow heat generated by the system to escape is provided. In one embodiment, the internal speaker ...	06/12/2007
7085392	Loudspeaker sound modulation appliance In combination with a loudspeaker assembly that includes a speaker diaphragm that is displaced to produce sound, the combination comprising a spinner element mounted to rotate in the path of sound waves produced by the speaker diaphragm; and a rotary drive for rotat...	08/01/2006
6978031	Loudspeaker sound modulation apparatus A loudspeaker assembly includes a speaker diaphragm that is displaced to produce sound, and a spinner element mounted to rotate in the path of sound waves produced by the speaker diaphragm, the spinner defining sound wave passing through openings, in said path. Illu...	12/20/2005
6837333	Loudspeaker system with forced air circulation and control circuit therefor A loudspeaker system has a diaphragm for producing sound, a loudspeaker driver mechanism operable for moving the diaphragm in response to an applied electrical signal from an audio signal source, a blower positioned for directing air under pressure over the loudspea...	01/04/2005
6834114	Multifunction acoustic device A rotor having a yoke is rotatably supported in a frame, and a stator provided in the frame at a central portion of the frame. An annular first permanent magnet is provided on the yoke, and an annular second permanent magnet is provided on the yoke. A diaphragm is s...	12/21/2004
6739425	Evacuated enclosure mounted acoustic actuator and passive attenuator This invention presents a novel means to passively achieve a compact moving-coil actuator with a very low natural frequency. The diaphragm and voice coil are mounted in a sealed enclosure from which the air is partially or completely evacuated. This reduces the air ...	05/25/2004
5825901	Rotary low-frequency sound reproducing apparatus and method Apparatus (21) is described for reproducing low frequency sound in response to an applied electrical signal having a rotary acoustic radiator (22) comprised of a chamber (26) having a rotor assembly (58) including a shaft (61) and movable vanes (71, 72) s...	10/20/1998
5579399	Acoustic resonator having mode-alignment-cancelled harmonics An acoustic resonator includes a chamber which contains a fluid. The chamber has a geometry which produces self-destructive interference of at least one harmonic in the fluid to avoid shock wave formation at finite acoustic pressure amplitudes. The chambe...	11/26/1996
5493615	Piezoelectric driven flow modulator An elliptically shaped flow modulator in a duct with a circular cross section is used to produce a time varying head loss in a steady fluid flow in the duct, which results in an unsteady volume velocity at the end of the duct which radiates an acoustic fi...	02/20/1996
5426707	Electrodynamic loudspeaker with cooling arrangement A loudspeaker, comprising a magnet unit which generates a magnetic field and a movable element suspended for resilient movement around a stable rest position for radiating sound with selected properties. The loudspeaker further comprises an electrical con...	06/20/1995
5255321	Acoustic transducer for automotive noise cancellation An acoustic transducer is disclosed for incorporation into an engine exhaust system or other gas carrying duct. The transducer produces pressure variations within the duct in accordance with an applied electrical signal. The transducer is especially suita...	10/19/1993
5191618	Rotary low-frequency sound reproducing apparatus and method Apparatus for reproducing low frequency sound in response to an applied audio signal having a rotary acoustic radiator comprised of an enclosure having a cylindrical sidewall and end walls adjoining the sidewall and forming a cylindrical chamber. A rotor ...	03/02/1993
5179595	Electrodynamic-fluidic transducer element for pneumatic loudspeaker The support (17) forming the element has a diameter of a magnitude order higher than its height which is itself of a magnitude order higher than its thickness. It is rigidified by means of two membranes each formed of a composite collar including, between...	01/12/1993
5140641	Servo valve loudspeaker Low frequency, high intensity sound is produced using a conduit having a flow of high velocity and low pressure air. A pair of sound ports are provided in the conduit, and a rotary valve connected to a reversible servomotor and audio source is employed to...	08/18/1992
5091959	Speaker system A sound speaker system has air chambers in a cylinder with a voice coil actuated vibrator and suitable inner wall speakers....	02/25/1992
5073937	Hydrodynamically pressure regulated loudspeaker systems The invention is a low frequency ported loudspeaker system comprising a hollow rectangular enclosure, the enclosure having a woofer driver airtight mounted to an aperature of the enclosure, changes in air pressure of the invention's enclosure's interior a...	12/17/1991
5060274	Hydrostatic speaker and speaker driver A hydrostatic speaker includes an oscillator, a partition diaphragm disposed in the oscillator to divide the oscillator into two chambers, at least one of which chambers serves as a fluid chamber to cause the partition diaphragm to vibrate in response to ...	10/22/1991
5054080	Pneumatic loudspeaker with a continuous pressurized fluid flow A pneumatic loudspeaker with a continuous pressurized fluid flow modulated by an obstacle forming an integral part of a moving armature with an electromagnetic coil supported by a leakproof elastic membrane. The moving armature comprises a cylindrical sup...	10/01/1991
5012457	Aquatic transducer system An underwater transducer system reproduces high-fidelity audio signals underwater, and detects and monitors low levels of sound activity, both adjacent to a body of water such as a swimming pool, and in the water. The system includes an underwater housing...	04/30/1991
4964100	Acoustic detection system An acoustic detection device having a parabolic dish antenna for gathering ound waves and providing a first stage of amplification, an exponential horn located at the focus of the parabolic dish antenna for further acoustic amplification, a fluidic gainblo...	10/16/1990
4763358	Rotary sound transducer At least one rotary vane in a tube is driven by a motor in response to an audio signal, causing production of sound through at least one opening in the tube....	08/09/1988
4757547	Air cooled loudspeaker An electrical blower is used to pass cooling air through a loudspeaker driver. The blower is connected in parallel to the leads between the amplifier and speaker such that the blower speed and cooling increases with increased power consumption and heat ge...	07/12/1988
4419545	Electret transducer An electret transducer comprising a diaphragm (3) arranged between first (1 or 1') and second electrodes with at least one electrode (2) arranged at some distance from the diaphragm as a stationary electrode formed with holes (5). An air gap (4) is formed...	12/06/1983
4382159	Blow actuated microphone In acoustical sound processing equipment, a combination microphone and blow actuated keying and unkeying means. The speaking person blows a first time into a tube to key the processing equipment and blows a second time to unkey the equipment. The person a...	05/03/1983
4219705	Sound production using large volume plasmas Apparatus for use in producing sound waves directly from electrical-acoustical and thermal acoustical energy. The invention embodies precisely controlled large volume plasmas which are capable of radiating very high levels of sound energy....	08/26/1980
4194095	Fluid flow control speaker system A fluid flow control system has a fluid source and plural flow pipes connected to the fluid source. Each of the pipes has an opening of a specific area corresponding to one of the bit orders of a PCM (Pulse Code Modulated) input signal. The flow-condition...	03/18/1980
4161632	Pneumatic acoustic transducer with ferromagnetic fluid valve A novel acoustic transducer utilizing a source of compressed air, the discharge of which is modulated by a ferromagnetic fluid. The ferromagnetic fluid is positioned in a magnetic gap, the intensity of which is modulated by a voice coil which in turn is a...	07/17/1979
4149034	Resolution enhanced sound detecting apparatus Apparatus for enhancing the resolution of a sound detector of the type which includes an acoustic mirror for focusing sound from an object onto a microphone to enable the determination of the location from which the sound arises. The enhancement apparatus...	04/10/1979
4129754	Reporting device A hand-held reporting device for use in environments wherein a minimum of sound in connection with use of the device is a priority and in environments having a high level of noise intensity. The device includes a barrel with a bell-shaped top, the latter ...	12/12/1978

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Class 381/165 - By modifying fluid flow