Inclination and direction responsive apparatus

• US 4,157,619 A
• Filed: 10/14/1977
• Issued: 06/12/1979
• Est. Priority Date: 10/14/1977
• Status: Expired due to Term

• Current Assignee: Scientific Drilling International, Inc.
• Original Assignee: Scientific Drilling Controls
• Inventors: Zuvela, Bernard R.
• Primary Examiner(s): Aegerter, Richard E.
• Assistant Examiner(s): Shepperd, John W.
• Application Number:
  US05/842,041
• Time in Patent Office: 606 Days
• Field of Search: 33/302, 33/304, 33/312, 33/313, 33/352, 33/355, 33/356, 33/357, 33/361, 33/366, 33/310, 33/351, 33/353, 73/189
• US Class Current: 33/352
• CPC Class Codes: E21B 47/02 Determining slope or direction
• CPC Class Codes: G01C 17/30 Earth-inductor compasses
• CPC Class Codes: G01C 9/06 Electric or photoelectric indication or reading means

Abstract

An inclination responsive device including a coil energized to produce a magnetic field extending along a normally vertical axis of the device, and a flux gate assembly adapted to respond to a horizontal component of that field upon tilting movement of the axis to an inclined non-vertical position, and to thereby produce an output which varies in response to changes in inclination. The flux gate assembly is desirably also responsive to the earth'"'"'s magnetic field or another ambient field to also produce an output representing directional orientation of the device with respect to the ambient field.

Claims

1. Inclination and direction responsive apparatus comprising:

a source of periodially fluctuating electrical current;

a support movable between a predetermined position of zero inclination in which an axis fixed relative to the support extends directly vertically and positions in which the axis is inclined at different angles;

a flux gate assembly carried by said support and subjected to an ambient magnetic field and energized by said current and acting to produce an output which varies in response to changes in directional orientation of said support relative to the field;

said assembly including magnetic core means mounted for leveling movement relative to said support to remain level in differently inclined positions of the support, and periodically driven to magnetic saturation by said current, with the time of saturation being altered by said ambient field; and

coil means flux linked to said core means in a relation producing said output varying with directional orientation;

an inclination coil carried by said support for movement therewith and flux linked to said flux gate assembly and energized to produce a magnetic field which extends essentially along said axis of the location of the flux gate assembly and tilts to differently inclined positions with the support and produces an output from the flux gate assembly which varies in response to changes in inclination;

means for selectively energizing or de-energizing said inclination coil in a relation producing a signal representing both direction and inclination when said inclination coil is energized, and producing a signal representing only direction when the inclination coil is de-energized; and

processing means for combining said signals representing both direction and inclination with said signal representing only direction to produce an output representing only inclination.

2. Inclination and direction responsive apparatus as recited in claim 1, in which said inclination coil extends about said core means and coil means of the flux gate assembly and is centered essentially about said axis which extends vertically in said position of zero inclination of the support.

3. Inclination and direction responsive apparatus as recited in claim 1, including a universal connection mounting said core means for said leveling movement relative to said support.

4. Inclination and direction responsive apparatus as recited in claim 1, in which said coil means are fixed relative to said support for movement therewith to positions of different inclination, and said core means are spaced from said coil means in a relation leaving room for leveling movement of the core means relative to the coil means as the latter move with the support to positions of different inclination.

5. Inclination and direction responsive apparatus as recited in claim 1, in which said core means form a closed loop of paramagnetic material centered essentially about said axis when the axis is in vertically extending position.

6. Inclination and direction responsive apparatus as recited in claim 1, in which said support includes a housing containing said core means and said coil means of the flux gate assembly, said inclination coil being wound about said housing and centered about said axis.

7. Inclination and direction responsive apparatus as recited in claim 1, in which said support contains a passage extending essentially along said axis and about which the core means and coil means are positioned, and through which an elongated member may extend for attachment to said support.

8. Inclination and direction responsive apparatus as recited in claim 1, including a buoy, a line extending downwardly from said buoy, and means mounting said support to said line.

9. Inclination and direction responsive apparatus as recited in claim 1, in which said support includes a housing containing a central tube extending essentially along said axis and about which said coil means and core means are carried, a buoy, and a line extending downwardly from the buoy and extending through said tube and connected thereto.

10. Inclination and direction responsive apparatus as recited in claim 1, in which said core means form a loop of paramagnetic material extending essentially about said axis, said coil means including at least one input coil encircling the material of said loop form core means at a side of said axis and energized by said periodically fluctuating current to periodically saturate the core.

11. Inclination and direction responsive apparatus as recited in claim 1, in which said core means form a closed loop of paramagnetic material centered essentially about said axis, said coil means including four coils extending about the material of said loop of paramagnetic material at evenly circularly spaced locations and connected to said source for energization by said fluctuating current.

12. Inclination and direction responsive apparatus as recited in claim 1, in which said core means form a closed loop of paramagnetic material centered essentially about said axis and mounted for universal pivotal leveling movement relative to said support, said coil means including input coil means wound about the material of said loop and energized by said fluctuating current and producing flux extending along an endless path through the closed loop of material, and a pair of output coils encircling the loop of paramagnetic material essentially diametrically at locations offset approximately 90 circular degrees from one another, and producing different components of said outputs.

13. Inclination and direction responsive apparatus as recited in claim 1, in which said core means form a closed loop of paramagnetic material extending essentially about said axis, said coil means including two output coils extending essentially diametrically about said loop of paramagnetic material and offset circularly from one another, and producing different components of said outputs.

14. Inclination and direction responsive apparatus as recited in claim 1, in which said core means form essentially a closed loop of paramagnetic material, and said coil means include two pairs of coils disposed about said loop with the coils of each pair at diametrically opposite locations and connected in series but reversely to said fluctuating current, and with each pair offset essentially 90°

from the other pair, there being output leads deriving output signals from midpoints between the coils of the two pairs.

15. Inclination and direction responsive apparatus as recited in claim 1, in which said support includes a housing containing a central mounting post extending essentially along said axis, there being a hollow essentially annular coil mounting structure in said housing and extending about said center post, said coil means including input coils wound about said core mounting structure with each turn of said input coils located entirely at one side of said axis, and with said input coils connected to said fluctuating current for energization thereby, said coil means including two output coils wound essentially diametrically about said coil mounting structure with their centers offset essentially 90 circular degrees from one another and producing two components of an output signal, said inclination coil extending about the outside of said input and output coils and essentially about said axis, said core means being an essentially annular core of paramagnetic material located in said hollow coil mounting structure, there being a universal connection in the coil mounting structure mounting said core for universal pivotal movement relative to said input and output coils and said inclination coil.

16. Inclination and direction responsive apparatus as recited in claim 1, in which said support includes a housing within which said core means are mounted for said leveling movement and which is completely filled with liquid to positively resist collapse under high pressures externally of the housing.

17. Inclination and direction responsive apparatus as recited in claim 1, in which said means for selectively energizing and de-energizing said inclination coil include means for energizing and de-energizing said coil automatically and intermittently.

20. Inclination and direction responsive apparatus as recited in claim 1, in which said source includes an oscillator delivering alternating current to said flux gate assembly, said coil means including input coil means and two output coils flux linked to said core and offset 90 circular degrees from one another, said means for energizing and de-energizing said inclination coil including circuitry timed by said oscillator and acting to intermittently energize and de-energize said inclination coil, there being a first pair of output circuits connected to said two output coils when said inclination coil is energized and producing said signal representing both inclination and direction in combination, and a second pair of output circuits connected to said output coils when said inclination coil is de-energized and producing said signal representing direction alone.

18. Inclination and direction responsive apparatus comprising:

a source of periodically fluctuating electrical current;

a support movable between a predetermined position of zero inclination in which an axis fixed relative to the support extends directly vertically and positions in which the axis is inclined at different angles;

a flux gate assembly carried by said support and subjected to an ambient magnetic field and energized by said current and acting to produce an output which varies in response to changes in directional orientation of said support relative to the field;

said assembly including magnetic core means mounted for leveling movement relative to said support to remain level in differently inclined positions of the support, and periodically driven to magnetic saturation by said current, with the time of saturation being altered by said ambient field; and

coil means flux linked to said core means in a relation producing said output varying with directional orientation;

an inclination coil carried by said support for movement therewith and flux linked to said flux gate assembly and energized to produce a magnetic field which extends essentially along said axis at the location of the flux gate assembly and tilts to differently inclined positions with the support and produces an output from the flux gate assembly which varies in response to changes in inclination;

means for automatically and intermittently energizing and de-energizing said inclination coil in a relation producing a signal representing both the direction and inclination outputs combined when said inclination coil is energized, and producing only a direction indicating output when the inclination coil is de-energized; and

means for subtracting said direction indicating output from said combined output which represents both inclination and direction, to produce an output representing only inclination.

19. Inclination and direction responsive apparatus comprising:

a source of periodically fluctuating electrical current;

a support movable between a predetermined position of zero inclination in which an axis fixed relative to the support extends directly vertically and positions in which the axis is inclined at different angles;

a flux gate assembly carried by said support and subjected to an ambient magnetic field and energized by said current and acting to produce an output which varies in response to changes in directional orientation of said support relative to the field;

said assembly including magnetic core means mounted for leveling movement relative to said support to remain level in differently inclined positions of the support, and periodically driven to magnetic saturation by said current, with the time of saturation being altered by said ambient field; and

coil means flux linked to said core means in a relation producing said output varying with directional orientation;

an inclination coil carried by said support for movement therewith and flux linked to said flux gate assembly and energized to produce a magnetic field which extends essentially along said axis at the location of the flux gate assembly and tilts to differently inclined positions with the support and produces an output from the flux gate assembly which varies in response to changes in inclination;

said source including an oscillator delivering alternating current to said flux gate assembly;

said coil means including input coil means and two output coils flux linked to said core and offset 90 circular degrees from one another;

circuitry timed by said oscillator and acting to intermittently energize and de-energize said inclination coil;

a first pair of output circuits connected to said two output coils when said inclination coil is energized and producing outputs representing both inclination and direction in combination;

a second pair of output circuits connected to said output coils when said inclination coil is de-energized and producing outputs representing direction alone; and

means for subtracting said second outputs from said first outputs to produce third outputs representing inclination alone.