Abstract: An impeller is rotatably mounted in a housing on the lower end of a sub which is lowered by means of a wire line into a bore hole. The fluid flow in either direction within the bore hole engages and rotates helical vanes of the impeller, which in turn rotates a digital sensing device. A magnetic coupling links the impeller to the sensing device which is sealably secured within the housing. Rotation of the sensing device in one direction produces a digital output signal which is distinguishable from the output signal produced when the sensing device is rotated in the opposite direction. The digital signal is produced by the rotation of a butterfly valve between signal emitter elements and signal receiving elements coupled to a distinguishing logic circuit. The direction of flow of fluids along the bore hole is thus easily detected in a reliable, highly sensitive manner.

Abstract: Improvement in free point indicators disclosed in U.S. Pat. No. 3,690,163. Discloses new strain sensing system having all electrical/electronic components, other than coil and diode components, located at earth's surface remote from high temperatures and shock loading. Includes a toroidal armature within the downhole tool having coils or windings to generate a pulsating magnetic flux field developed by an alternating current. A U-shaped permanent magnet is disposed such that a portion of its constant magnetic flux field occupies physical space common with a portion of the pulsating magnetic flux field for mutual influence. A diode provided in series with each winding limits electrical current passing through each winding to pulsating DC. The constant flux of the magnet and the pulsating flux of the coils are relatively positioned in opposing sense whereby the current passing through each winding is of designated magnitude.

Abstract: Borehole orienting apparatus is provided wherein motion is imparted to a permanent magnet assembly to generate a moving magnetic field and receiver means are provided such that measurable signals are induced therein when the magnetic field is distorted due to the presence of a ferrous anomaly. The receiver means is rotated to produce an azimuthal scan such that there are induced in the receiver means signals from which the azimuthal location of the anomaly can be determined.