Class 367/182 - Moving coil

Subclass of Class 367 - Communications, electrical: acoustic wave systems and devices
Definition: Subject matter in which acoustic wave forces move an electric
No. of patents: 32
Last issue date: 01/17/2012

Number	Title	Issue Date
8098546	Geophone having improved sensitivity A geophone utilizing an Alnico-9 magnet and having an improved sensitivity over Alnico-9 geophones of prior art through the lengthening of the parasitic air gap between the upper and lower pole pieces which, results in less magnetic flux leakage. The flux concentrat...	01/17/2012
8027225	Methods and systems for seismic sensors Methods and systems for determining coil eccentricity of seismic sensors configured or designed for use in seismic signal detection. A direct electrical current is applied to a moving coil of a seismic sensor such that the moving coil is dislocated from a neutral po...	09/27/2011
7443766	Sensor assembly A sensor assembly includes a seismic sensor element and a shell. The shell at least partially surrounds the sensor element to shield the sensor element from a magnetic field that is generated outside of the shell. ...	10/28/2008
7406002	Method and apparatus for the acquisition of seismic movements The method and the apparatus disclosed serve to acquire seismic induced movements. A coil and a permanent magnet are contained in an enclosure and the seismic movements induce a relative movement between said coil and said magnet. The current induced into the coil i...	07/29/2008
7324406	Sensor arrangement for seismic waves A sensor arrangement is provided for use in the seismic investigation of geological formations below the seabed. A plurality of sensor nodes (20) are provided and are positioned gfor deployment on the seabed to collect pressure waves and shear waves from the ...	01/29/2008
7292504	Seismic sensors A method for compensating the effect of gravity on seismic sensors such as geophones and a gravity effect-free seismic sensor are disclosed. The gravity effect-free seismic sensor of the present invention includes primary sensor (100) operatively responsive t...	11/06/2007
7099235	Geophone and method of manufacturing a geophone A vibration transducer such as a geophone, comprising a central pole piece (110) with a magnet (112) and coil (118) concentrically arranged around it. The position of the magnet (112) is fixed relative to the pole piece (110) and t...	08/29/2006
6922374	Double-ended geophone A geophone including conductive terminals positioned on opposite sides of the geophone housing. The geophone includes a pair of coils resiliently mounted within the geophone housing and a magnet. A first end plate, a first spring, and a first coil support provide a ...	07/26/2005
6918299	Method and apparatus for improving performance of a force balance accelerometer based on a single-coil velocity geophone The invention concerns methods and apparatus for improving the performance of a force-balance accelerometer based upon a conventional, single-coil, velocity geophone. Specifically, the operating temperature range is increased through the use of both a temperature-co...	07/19/2005
6618325	Method and apparatus for controlling damping and in situ determination of frequency response for high bandwidth force-balance single-coil geophone Force-balance feedback geophone apparatus and methods for characterization of the geophone apparatus. Control inputs (65) provide for switching (61, 63) of a force-balance feedback geophone between operational states, thereby allowing for in situ determin...	09/09/2003
6483778	Systems and methods for passively compensating transducers Systems and methods of the invention can equalize the pressure between an interior cavity and an environment exterior to the interior cavity, while providing for acoustic isolation between the two environments so that acoustic energy propagating through o...	11/19/2002
6412592	Electrically inclination compensated device for picking up elastic waves A device which picks up elastic waves, such as a geophone for example, in positions far from the natural operating position for which it is designed. The device comprises an electrodynamic pickup including a magnet (1), a moving coil (2) placed in the mag...	07/02/2002
6075754	Single-coil force balance velocity geophone The invention converts a conventional velocity geophone to a force-balance accelerometer. A single, spring supported geophone coil, in conjunction with a permanent magnet assembly fixed to the geophone housing, is used as both an electromagnetic velocity ...	06/13/2000
5633463	Earthquake detector An earthquake detector including a platform fixedly coupleable to a recipient surface for receiving vibrations generated as a result of an earthquake; a spring-loaded frame secured to the platform; an alarm mechanism coupled to the spring-loaded frame for...	05/27/1997
5469408	High resolution geophone A geophone is disclosed that has a cylindrical housing closed at one end by a bottom and the other end by a top. A magnet assembly of a rare earth magnet with pole pieces at each end of the magnet is centrally mounted in the housing providing an annular s...	11/21/1995
5305288	Variable reluctance acoustic projector A variable reluctance acoustic projector includes a piston structure that provides rigid retention and precise alignment of electromagnetic cores within the projector housing. The piston structure provides a pair of metallic piston blocks having cavities ...	04/19/1994
5299176	Balanced armature transducers with transverse gap An electromechanical transducer having permanent magnet means forming a bias field in a region between poles, and a vibratable armature having a first part in that region. The armature has a second part extending from the first part substantially external...	03/29/1994
5214620	Electrically driveable shockwave source An electrically driveable shockwave source for generating acoustic shockwaves of the type suitable for medical therapy, as a coil arrangement and a membrane disposed adjacent the coil arrangement. The membrane and/or the coil arrangement is formed by a mu...	05/25/1993
5199005	Electromagnetic drive assembly for under water sonar transducer A sonar projector having a pair of opposed oscillating pistons driven by an electromagnetic assembly is provided with reduced weight and high power by forming the electromagnetic assembly with a permanent magnet structure consisting of two coaxial longitu...	03/30/1993
5172345	Geophone system A geophone system for measuring mechanical vibrations such as seismic waves include a mechanical transducer with an electronic processing circuit. The mechanical transducer includes an inertial mass adapted to be excited by an input acceleration signal an...	12/15/1992
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
4821245	Electromagnetic transducer An electromagnetic transducer for use in generating transient acoustic pulses in particular for medical purposes such as the destruction of kidney stones. The transducer comprises at least one pair of conductors, of which one is held against movement by a...	04/11/1989
4764762	Earthquake alarm assembly An alarm assembly specifically designed to warn sleeping occupants within a dwelling structure as to the occurrence of earth tremors such as those caused by relatively serious earthquakes wherein an activating member is movably positioned relative to a su...	08/16/1988
4757548	Speaker system and dome-shaped enclosure therefor A speaker system having a magnet and voice coil are mounted within a dome-shaped enclosure in such a way as to be capable of transmitting sonic vibrations and audio waves through a liquid medium or solid structure, the dome-shaped enclosure cooperating wi...	07/12/1988
4689997	Motion detector suitable for detecting earthquakes and the like A motion detector for detecting earthquakes or the like provides a warning signal when vibrations having a frequency of the order of the natural frequency of an earthquake tremor are detected. A preferred embodiment of the device employs a vertical spring...	09/01/1987
4597070	Geophone An improved geophone for seismic prospecting is disclosed which features plural magnets of varying mass oscillating with varying frequencies within one or plural coils whereby the frequency response of the geophone may be optimized....	06/24/1986
4538203	Passive mass-spring type of sensing device having electronic damping A passive mass-spring type of sensing device or other such device for monitoring a particular parameter, for example mechanical vibration, is disclosed herein. This device utilizes an electrically conductive coil having a given impedance disposed within a...	08/27/1985
4466084	Seismometer A seismometer comprising a permanent magnet fixed to a supporting plate, a thin flexible blade, one of whose ends is embedded in a support which is itself fixed to the supporting plate and the other end of which carries a coil which moves freely in the ai...	08/14/1984
4466083	Low frequency, broadband, underwater sound transducer An electrodynamic transducer has broadband operation and is suitable for erwater use. The transducer has a flexible rubber seal to assist in keeping the unit watertight. New features include a large flared air passage, a coil of wire that is rectangular ...	08/14/1984
4159464	Geophone with damping coil A conventional electromagnetic geophone includes a coil assembly that is spring-suspended in an air gap between concentric pole pieces of a magnet. The coil assembly is wound on the outer wall of a bobbin. The bobbin is typically made from or includes a m...	06/26/1979
4152692	Low distortion, high sensitivity seismometer A compact, high sensitivity low distortion seismometer having an elongated tubular outer pole formed of a magnetic material, a magnetic assembly located in the interior of the outer pole and having a permanent magnet and a pair of conductive pole pieces e...	05/01/1979
4051718	Apparatus for measuring the velocity of low frequency vibrations The invention concerns apparatus for measuring the velocity of low frequency mechanical vibrations, comprising two springs between which a vibratable mass is secured, two electric coils mechanically coupled to the mass, a permanent magnet core in each coi...	10/04/1977

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Class 367/182 - Moving coil