Three-axis sensor
AssigneeWestern Atlas International, Inc.
InventorsWilliam O. McNeel, James A. Sackett, Joe N. Wood, Julian Soliz, III
Life of this patent
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Abstract
A transducer assembly for use along the surface of the earth or in a borehole to detect seismic signals along mutually orthogonal axes. The transducer assembly includes at least two geophones or accelerometers gimbally-mounted within a housing such that when the housing is oriented at substantially any angle, the enclosed geophones remain in their respective planes with respect to gravity and their axes of sensitivity to the seismic signals remain orthogonal to each other.
Claims20
An apparatus for detecting seismic signals along orthogonal axes, consisting essentially of:
- (a) a housing having a longitudinal axis;
- (b) at least two gimbals located within the housing, the gimbals providing two degrees of rotational freedom perpendicular to the longitudinal axis of the housing, each gimbal having an outer table pivotally coupled to the housing perpendicular to the longitudinal axis thereof to define a first pivot axis, and an inner table pivotally coupled to the outer table at a right angle to the first pivot axis to define a second pivot axis, the first pivot axis of each gimbal is contained in a common plane passing through the housing and contains the longitudinal axis of the housing;
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- (c) at least two seismic sensors disposed within the housing, each having an axis of sensitivity to the seismic signals and each suspended within the housing by one of said gimbal, the sensors oriented such that their axes of sensitivity are orthogonal to each other, and remain orthogonal with the longitudinal axis of the housing inclined from a horizontal.
An apparatus for use in a bore hole to detect seismic signals along orthogonal axes, consisting essentially of in combination:
- (a) a housing having a longitudinal axis and adapted to engage the bore hole;
- (b) a plurality of gimbals located within the housing for providing two degrees of rotational freedom perpendicular to the longitudinal axis of the housing, each gimbal having a first and a second table, the first table pivotally coupled to the housing to define a first pivot axis perpendicular to the longitudinal axis of the housing with the first pivot axis for each gimbal contained in a common plane including the longitudinal axis of the housing, the second table concentric with and pivotally coupled to the first table at a right angle to the first pivot axis to define a second pivot axis perpendicular to the longitudinal axis of the housing;
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- (c) a plurality of detectors disposed within the housing and oriented along orthogonal axes, the detectors being able to maintain their orthogonal orientation to each other with the longitudinal axis of the housing inclined with respect to a horizontal plane.
A transducer assembly for detecting seismic signals in the earth along mutually orthogonal axes, comprising in combination:
- (a) a rigid housing, having a longitudinal axis, for engaging the earth,
- (b) a frame within the housing and rigidly coupled thereto;
- (c) a plurality of gimbals located within the housing providing two degrees of rotation freedom perpendicular to the longitudinal axis of the housing, each gimbal having an outer and an inner table, the outer table being pivotally connected to the frame so as to define a first pivot axis perpendicular to the longitudinal axis, of the housing, the inner table being concentrically received by the outer table and being pivotally connected thereto at a right angle to the first pivot axis to define a second pivot axis perpendicular to the longitudinal axis of the housing;
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- (d) a plurality of detectors disposed within the housing and mounted on a respective gimbal so that the seismic signals are received along orthogonal axes as long as the longitudinal axis of the housing is inclined with respect to a horizontal plane.
A transducer assembly for detecting seismic signals along orthogonal axes, consisting essentially of in combination:
- (a) an elongate housing having a longitudinal axis;
- (b) at least two gimbals disposed within and coupled to the housing, each of the gimbals having a first and a second table, the first table being pivotally coupled to the housing at a right angle to the longitudinal axis to define a first pivot axis, the second table concentrically disposed within the first table and pivotally coupled thereto at a right angle to the first pivot axis to define a second pivot axis, each of the gimbals providing two degrees of rotational freedom perpendicular to the longitudinal axis of the housing;
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- (c) a plurality of seismic sensors disposed within the housing, each of the seismic sensors mounted on the second table of a respective gimbal so that each of the seismic sensors detects the seismic signals along an orthogonal axis with the longitudinal axis of the housing inclined with respect to a horizontal datum.
Dependencies are inferred from the claim text.