Sensor assembly

• US 6,367,366 B1
• Filed: 06/20/2000
• Issued: 04/09/2002
• Est. Priority Date: 12/02/1999
• Status: Expired due to Term

• Current Assignee: WWT North America Holdings, Inc.
• Original Assignee: Western Oiltools Ltd.
• Inventors: Krueger, Rudolph Ernst, Moore, Bruce Norman, Estep, James W., Bloom, Duane, Yoo, Kwang M.
• Primary Examiner(s): LOPEZ, FRANK D
• Application Number:
  US09/599,071
• Time in Patent Office: 658 Days
• Field of Search: 91/1, 92/5.R
• US Class Current: 92/5.00R
• CPC Class Codes: E21B 23/001 Self-propelling systems or apparatus, e.g. for moving tools within the horizontal portion of a borehole
• CPC Class Codes: E21B 23/08 Introducing or running tools by fluid pressure, e.g. through-the-flow-line tool systems
• CPC Class Codes: E21B 4/18 Anchoring or feeding in the borehole
• CPC Class Codes: E21B 44/005 Below-ground automatic control systems
• CPC Class Codes: E21B 7/062 the tool shaft rotating inside a non-rotating guide travelling with the shaft E21B7/067 and E21B7/068 take precedence

Abstract

A sensor assembly including a sensor mounted on the piston and a transmitter mounted on either the piston or cylinder. Preferably the transmitter includes a wheel which engages the wall of the cylinder so as to rotate as the piston reciprocates within the cylinder. The wheel includes one or more magnets which emit a magnetic field that is received by the sensor as the wheel rotates whereby the sensor provides a signal indicative of the rotation of the wheel. The sensor then sends the signal to a logic component which determines the direction, travel and position of the piston within the cylinder.

Claims

1. An apparatus for determining the travel of a piston within a cylinder, comprising:

a sensor disposed on the piston; and

a transmitter disposed on the piston without contacting the sensor and transmitting signals indicative of the distance of travel of the piston within the cylinder;

the sensor receiving the signals from the transmitter to determine the travel of the piston.

2. The apparatus of claim 1 wherein said sensor is a Wiegand sensor.

3. The apparatus of claim 1 wherein said transmitter includes at least one magnet emitting an electric field to be sensed by said sensor.

4. The apparatus of claim 1 wherein said transmitter includes at least one magnet disposed on a wheel rotatably mounted on the piston.

5. The apparatus of claim 4 wherein said wheel is mounted on arms having one end affixed to the piston.

6. The apparatus of claim 4 wherein said wheel includes two oppositely charged magnets on opposite sides of said wheel'"'"'s outer circumference.

7. The apparatus of claim 6 wherein said sensor senses the magnetic field of said magnets upon rotation of said wheel and emits electric pulse signals indicative thereof.

8. The apparatus of claim 7 wherein said sensor sends said electric pulse signals to a logic member which determines the direction and distance of travel of the piston.

9. The apparatus of claim 1 further including a logic member receiving signals from said sensor to determine the displacement of the piston within the cylinder.

10. The apparatus of claim 1 wherein the signals from the transmitter are magnetic signals.

11. An assembly comprising:

a cylinder;

a piston disposed within said cylinder;

said piston including a sensor and a transmitting wheel;

said transmitting wheel including oppositely charged magnets positioned on opposite sides of said wheel'"'"'s outer circumference; and

said sensor sensing the reversals in polarity of said magnets every time said wheel rotates 180°

.

12. The apparatus of claim 11 wherein said sensor sends an electric pulse signal to a logic member which determines the position of said piston within said cylinder.

13. The assembly of claim 12 wherein said sensor is a Weigand sensor.

14. The assembly of claim 12 wherein said sensor transmits a stream of electric pulses for every 180°

rotation of said wheel and a position of said piston within said cylinder being calculated from a diameter of said wheel with each pulse corresponding to one-half of said wheel circumference.

15. A method of determining the position of a piston within a cylinder, comprising:

rotating a wheel as the piston travels within the cylinder;

transmitting a signal from a location on the circumference of the wheel;

sensing the signal as the wheel rotates to count the number of rotations; and

determining the distance of travel of the piston from the wheel'"'"'s circumference and the number of rotations of the wheel.

16. The method of claim 15 further including sending the number of rotations of the wheel to a logic member to calculate the position of the piston.

17. An apparatus for determining the travel of a piston within a cylinder, comprising:

a sensor disposed on the piston; and

a transmitter axially fixed to the piston and transmitting signals indicative of the distance of travel of the piston within the cylinder;

the sensor receiving the signals from the transmitter to determine the travel of the piston.

18. The apparatus of claim 17, wherein the signals from the transmitter are magnetic signals.

19. An apparatus for determining the travel of a piston within a cylinder, comprising:

a sensor disposed on the piston; and

a transmitter including at least one magnet disposed on a wheel rotatably mounted on the piston;

the sensor receiving the signals from the transmitter to determine the travel of the piston.

20. An apparatus for determining the travel of a piston within a cylinder, comprising:

a sensor disposed on the piston; and

a transmitter disposed on the piston without contacting the sensor, the transmitter transmitting magnetic signals indicative of the distance of travel of the piston within the cylinder;

the sensor receiving the signals from the transmitter to determine the travel of the piston.

21. An apparatus for determining the travel of a piston within a cylinder, comprising:

a sensor disposed on the piston; and

a transmitter axially fixed to the piston, the transmitter transmitting magnetic signals indicative of the distance of travel of the piston within the cylinder;

the sensor receiving the signals from the transmitter to determine the travel of the piston.