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Underground pipe detector
Patent #: 3967282
Issued on: 06/29/1976
Inventor: Young , et al.
Apparatus for and methods of seismic prospecting
Patent #: 4006445
Issued on: 02/01/1977
Inventor: Howell
Apparatus for measuring the distance to the floor of the cargo hold of a ship through intervening bulk material
Patent #: 4070625
Issued on: 01/24/1978
Inventor: Harpster
Method for locating buried markers which are disposed along the path of an underground conductor
Patent #: 4119908
Issued on: 10/10/1978
Inventor: Cosman , et al.
Laser interferometry detection method/apparatus for buried structure
Patent #: 4172382
Issued on: 10/30/1979
Inventor: Murphy , et al.
Acoustic archeological mapping method
Patent #: 4213194
Issued on: 07/15/1980
Inventor: Spurlock , et al.
Digital mineral logging system
Patent #: 4227405
Issued on: 10/14/1980
Inventor: West
Amplitude tilt correction apparatus
Patent #: 4245353
Issued on: 01/13/1981
Inventor: Bynum
Electromagnetic subsoil prospecting process using an asymptotic low frequency range
Patent #: 4258322
Issued on: 03/24/1981
Inventor: Rocroi , et al.
Extended AGC for a radio receiver
Patent #: 4313218
Issued on: 01/26/1982
Inventor: O'Donnell, Jr. , et al.
Method of determining the location of a deep-well casing by magnetic field sensing
Patent #: 4372398
Issued on: 02/08/1983
Inventor: Kuckes
Apparatus for determining the distance to a concealed conductive object which is radiating an alternating current signal
Patent #: 4387340
Issued on: 06/07/1983
Inventor: Peterman
Apparatus and method for locating and tracking magnetic objects or sources
Patent #: 4427943
Issued on: 01/24/1984
Inventor: Cloutier , et al.
Grade monitoring and steering apparatus
Patent #: 4438820
Issued on: 03/27/1984
Inventor: Gibson
System for measuring downhole drilling forces
Patent #: 4445578
Issued on: 05/01/1984
Inventor: Millheim
Push drill guidance indication apparatus
Patent #: 4452075
Issued on: 06/05/1984
Inventor: Bockhorst , et al.
Frequency dependent pulsed gain modulated concealed structure locator
Patent #: 4458204
Issued on: 07/03/1984
Inventor: Weber
Noise floor automatic gain control
Patent #: 4479254
Issued on: 10/23/1984
Inventor: Craiglow
Tracing electrical conductors by high-frequency loading and improved signal detection
Patent #: 4491785
Issued on: 01/01/1985
Inventor: Pecukonis
Personnel monitoring and locating system
Patent #: 4495496
Issued on: 01/22/1985
Inventor: Miller, III
Apparatus including a pair of automatic gain controlled amplifiers for determining the lateral direction to a concealed conductive object
Patent #: 4520317
Issued on: 05/28/1985
Inventor: Peterman
Detecting buried pipeline depth and location with electromagnetic triangulation
Patent #: 4542344
Issued on: 09/17/1985
Inventor: Darilek , et al.
Receiver input circuit
Patent #: 4580288
Issued on: 04/01/1986
Inventor: Rinderle
Apparatus and method to communicate bidirectional information in a borehole
Patent #: 4593559
Issued on: 06/10/1986
Inventor: Brown , et al.
Tracing electrical conductors by high-frequency constant-energy-content pulse loading
Patent #: 4642556
Issued on: 02/10/1987
Inventor: Pecukonis
Method and apparatus for protecting buried optical fiber cable
Patent #: 4652861
Issued on: 03/24/1987
Inventor: Domes
Method and apparatus for electromagnetically surveying a remote elongate conductor employing a detector assembly having plural electromagnetic transducer assemblies
Patent #: 4672321
Issued on: 06/09/1987
Inventor: Howell
Method and apparatus for installment of underground utilities
Patent #: 4674579
Issued on: 06/23/1987
Inventor: Geller , et al.
Method and apparatus including spaced antennas for determining the trace and depth of underground metallic conductors
Patent #: 4691165
Issued on: 09/01/1987
Inventor: Szedlmajer
Radar apparatus
Patent #: 4691204
Issued on: 09/01/1987
Inventor: Hiramoto
Method for determining the location of a deep-well casing by magnetic field sensing
Patent #: 4700142
Issued on: 10/13/1987
Inventor: Kuckes
Metal detector having digital signal processing
Patent #: 4709213
Issued on: 11/24/1987
Inventor: Podhrasky
Method and apparatus employing received independent magnetic field components of a transmitted alternating magnetic field for determining location
Patent #: 4710708
Issued on: 12/01/1987
Inventor: Rorden , et al.
Technique for steering and monitoring the orientation of a powered underground boring device
Patent #: 4714118
Issued on: 12/22/1987
Inventor: Baker , et al.
Apparatus for observing the passage of a pig in a pipeline
Patent #: 4714888
Issued on: 12/22/1987
Inventor: French , et al.
Method and apparatus for communicating with downhole measurement-while-drilling equipment when said equipment is on the surface
Patent #: 4736204
Issued on: 04/05/1988
Inventor: Davison
Shield tunneling system capable of electromagnetically detecting and displaying conditions of ground therearound
Patent #: 4774470
Issued on: 09/27/1988
Inventor: Takigawa , et al.
Superheterodyne receiver
Patent #: 4776040
Issued on: 10/04/1988
Inventor: Ichikawa , et al.
Method and apparatus for installment of underground utilities
Patent #: 4787463
Issued on: 11/29/1988
Inventor: Geller , et al.
Subterranean target location by measurement of time-varying magnetic field vector in borehole
Patent #: 4791373
Issued on: 12/13/1988
Inventor: Kuckes
Well data transmission system using a magnetic drill string for transmitting data as a magnetic flux signal
Patent #: 4800385
Issued on: 01/24/1989
Inventor: Yamazaki
An above-ground arrangement for and method of locating a discrete in ground boring device
Patent #: 4806869
Issued on: 02/21/1989
Inventor: Chau , et al.
Inground boring technique including real time transducer
Patent #: 4864293
Issued on: 09/05/1989
Inventor: Chau
Technique for steering a downhole hammer
Patent #: 4867255
Issued on: 09/19/1989
Inventor: Baker , et al.
Two-way communication system for winning machines in underground mining
Patent #: 4870697
Issued on: 09/26/1989
Inventor: Weber
System and method for locating an underground probe having orthogonally oriented magnetometers
Patent #: 4875014
Issued on: 10/17/1989
Inventor: Roberts, et al.
Homing technique for an in-ground boring device Patent #: 4881083
Issued on: 11/14/1989
Inventor: Chau, et al.
November 23, 2010. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
