BACK BAR LINKAGE ASSEMBLY

Abstract

A linkage for mounting the elements of an in-line pipeline inspection vehicle. The embodiment allows measurements to be taken while constraining the vehicle to travel within an axial plane of the pipeline.

Description

RELATED APPLICATIONS

This application claims the benefit of co-pending U.S. Provisional Patent Application Ser. No. 61/065,462 filed Feb. 11, 2008.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is the side view of a system of the embodiment.

FIG. 2 is a side view of the embodiment.

FIG. 3 is an exploded view of the embodiment.

FIG. 4 is an exploded view of the front linkage of the embodiment.

FIG. 5 is an exploded view of the rear linkage of the embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENT

Elements of the embodiment are:

1 odometer wheel

2 polyurethane supporting and driving cup

3 power canister

4 flexible coupler

5 ID-OD discrimination sensors

6 electronic component canister

7 magnets

8 sensor heads

9 magnetic assembly body

10 linkage assembly

11 magnetic back bar

12 magnetic back bar linkage mount

13 front linkage mount

14 front mid link

15 rear mounting link

16 rear plate side link

17 rear backside link

18 hinge pin

19 locking snap ring

Referring to FIG. 1, a magnetic flux leakage pipeline inspection vehicle is shown in accordance with the embodiment. The vehicle comprises a canister containing a power source 3, a canister containing a data acquisition and computation system 6 and a magnetic assembly body 9 to which the magnets 7 and the primary sensor head assemblies 8 are attached. Depending upon the configuration of the in-line inspection vehicle and the size of the pipeline to be inspected, there may be more or fewer canisters. The embodiment uses magnets 7 and sensors 8 to identify pipeline anomalies, odometer wheels 1 to locate anomalies in the pipeline wall, and polyurethane cups 2 to support and propel the vehicle in the pipeline. The canisters are attached by flexible couplers 4.

As shown in FIG. 2, the embodiment comprises a back bar 11 which holds magnets 7 and sensor heads 8 and a back bar linkage assembly 12. The front end of the back bar 11 and linkage mount 12 has a front mid link 14 and a front linkage mount 13 that is fastened to the magnetic assembly body 9. The front and rear ends of the back bar 11 have a linkage mount 12. The rear linkage has a rear backside link 17, a rear plate side link 16, and a rear mounting link 15 to complete the rear linkage assembly. The combined rear plate side link 16 and rear backside link 17 allow both radial translation and rotation in an axial plane while confining the assembly body 9 to movement within an axial plane and limiting both translation and rotation in the plane.

As shown in FIG. 3, the linkage mount 12, the rear backside link 17, the rear plate side link 16 and the rear mounting link 15 are assembled by the use of hinge pins 18. The back bar assembly is integral to the magnetic assembly body of the vehicle with bolts passing through bolt holes located at the front of the front linkage mount 13 and the rear mounting link 15.

The exact dimensions of the back bar will vary depending upon the size of the inspection vehicle. As the size of the vehicle varies, the number of back bars will increase for larger vehicles or decrease for smaller vehicles. The shape of the magnetic back bar linkage mount 12 matches the shape and dimensions of the back bar 11.

As shown in FIG. 4, the front end of the linkage system comprises three interlocking links joined by hinge pins 18 at the front end of the magnetic back bar linkage mount 12, both ends of the front mid link 14 and the rear end of the magnetic back bar linkage mount 13. The hinge pins 18 are then held in place by the locking snap rings 19.

As shown in FIG. 5, the rear end of the linkage system comprises four interlocking links joined by hinge pins 18 at the rear end of the magnetic back bar linkage mount 12, both ends of the rear backside link 17, both ends of the rear plate side link 16, and at the top of the rear mounting link 15. Again, as in the front end of the linkage assembly, the hinge pins 18 are held in place by the locking snap rings 19.

Claims

1. A linkage for supporting the elements of an instrument pig, comprising:

a back bar assembly;

a front linkage connected to said instrument pig and said back bar assembly; and

a rear linkage connected to said instrument pig and said back bar assembly.

2. The instrument pig of claim 1, wherein said instrument pig is used for the in-line inspection of a pipeline.

3. The front linkage of claim 1, wherein said front linkage comprises multiple links.

4. The front linkage of claim 3, wherein said front linkage comprises two links.

5. The rear linkage of claim 1, wherein said rear linkage comprises multiple links.

6. The rear linkage of claim 5, wherein said rear linkage comprises three links.

7. The rear linkage of claim 6, wherein said rear linkage allows said back bar assembly to stay parallel to the inside surface of said pipeline as said instrument pig moves through the interior of said pipeline.

8. The rear linkage of claim 7, wherein said rear linkage restricts said instrument pig to movement within an axial plane of said pipeline.