ATTACHMENT DEVICE AND METHOD FOR FASTENING ELECTRICAL CABLE MONITORING INSTRUMENTS TO ELECTRICAL CABLES

• US 20080088299A1
• Filed: 10/12/2006
• Published: 04/17/2008
• Est. Priority Date: 10/12/2006
• Status: Active Grant

• Current Assignee: James G. Biddle Company, Sigma Space Corp.
• Original Assignee: Sigma Space Corp.
• Inventors: Sagl, Andrew Paul, Ferguson, William Eakins, Stitt, Jeffrey Lyn, Wolfe, Gregory Robert
• Granted Patent: US 7,570,045 B2
• Time in Patent Office: Days
• US Class Current: 324/126
• CPC Class Codes: G01R 1/02 General constructional details
• CPC Class Codes: G01R 1/22 Tong testers acting as secondary windings of current transformers
• CPC Class Codes: G01R 15/14 Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks

Abstract

The present invention is an attachment device and a method for fastening and removing an electrical cable monitoring instrument to an electrical cable. The attachment device comprises monitoring instrument sensor with opening for positioning electrical cable such that said electrical cable can be positioned to pass through the sensitive volume at least partially surrounded by said sensor, at least one elongated elastic member securely attached to said cable monitoring instrument such that, when elastically deformed to a shape characterized by high mechanical energy such that deformed elastic member allows said electrical cable access to and from the sensitive volume at least partially surrounded by said monitoring instruments sensor. The elongated elastic member, when relaxed to the a shape characterized by lower mechanical energy than high mechanical energy shape, with the electrical cable positioned to pass through sensitive volume, applies elastic force to the electrical cable to hold the electrical cable passing through the sensitive volume firmly and securely in contact with the cable monitoring instrument with no relative motion.

Claims

1. An attachment device for fastening an electrical cable monitoring instrument to an electrical cable comprising:

a monitoring instrument sensor with opening for positioning electrical cable such that said electrical cable can be positioned to pass through the sensitive volume at least partially surrounded by said sensor,

at least one elongated elastic member securely attached to said cable monitoring instrument such that, when elastically deformed to a shape characterized by high mechanical energy such that deformed elastic member allows said electrical cable access to and from the sensitive volume at least partially surrounded by said monitoring instruments sensor,

said elongated elastic member, when relaxed to the a shape characterized by lower mechanical energy than said high mechanical energy shape, with the electrical cable positioned to pass through said sensitive volume, applies elastic force to said electrical cable to hold the electrical cable passing through the sensitive volume firmly and securely in contact with the cable monitoring instrument with no relative motion.

2. The attachment device for fastening an electrical cable monitoring instrument to an electrical cable of claim 1 where at least one elongated elastic member is at least partially positioned outside the sensitive volume at least partially surrounded by said monitoring instrument sensor.

3. The attachment device for fastening an electrical cable monitoring instrument to an electrical cable of claim 1 where the elastic deformation and associated mechanical energy is predominantly stored in at least one elongated elastic member comprised of two elongated elastic members joined by a connecting member, said two elongated elastic members are deformable in the plane perpendicular to the electrical cable axis.

4. The attachment device for fastening an electrical cable monitoring instrument to an electrical cable of claim 3, where two elongated elastic members joined by a connecting member deformable in the plane perpendicular to the electrical cable axis further comprise one or more concave portions when observed from the direction originating on the cable axis, said concave portion or portions having openings larger than the diameter of said electrical cable.

5. The attachment device for fastening an electrical cable monitoring instrument to an electrical cable of claim 1 where the elastic deformation and associated mechanical energy is predominantly stored in at least one elongated elastic member deformable in the plane containing said electrical cable axis.

6. The attachment device for fastening an electrical cable monitoring instrument to an electrical cable of claim 1 further comprising at least one short helical spring such that the elastic deformation and associated mechanical energy is predominantly stored in said short helical spring or springs.

7. The attachment device for fastening an electrical cable monitoring instrument to an electrical cable of claim 1 further comprising at least one elastic body such that the elastic deformation and associated mechanical energy is predominantly stored in said elastic body or bodies.

8. The attachment device for fastening an electrical cable monitoring instrument to an electrical cable of claim 7 where the elastic body is an elastomeric body elastically deformable in the direction perpendicular to the longest dimension of said elongated elastic member.

9. The attachment device for fastening an electrical cable monitoring instrument to an electrical cable of claim 7 where the elastic body is a tightly wound helical spring deformable in the direction perpendicular to the longest dimension of said elongated elastic member.

10. The attachment device for fastening an electrical cable monitoring instrument to an electrical cable of claim 1 further comprising a Faraday shield that at least partially encloses the electrical cable monitoring instrument.

11. The attachment device for fastening an electrical cable monitoring instrument to an electrical cable of claim 10 where at least one elongated elastic member is securely attached to said Faraday shield.

12. The attachment device for fastening an electrical cable monitoring instrument to an electrical cable of claim 10 where at least one elongated elastic member is securely attached to the monitoring instrument sensor not enclosed by and separate from the Faraday shield.

13. A method for fastening to and removing from an electrical cable an electrical cable monitoring instrument which uses the attachment device, the attachment device comprised of a monitoring instrument sensor with opening for positioning electrical cable such that said electrical cable can be positioned to pass through the sensitive volume at least partially surrounded by said sensor, at least one elongated elastic member securely attached to said cable monitoring instrument such that, when elastically deformed to a shape characterized by high mechanical energy,

the method for fastening to and removing from an electrical cable the electrical cable monitoring instrument comprising steps:

a) attaching a hot stick to the mounting bracket,

b) bringing the electrical cable monitoring instrument in proximity to the electrical cable using the hot stick,

c) engaging the electrical cable with at least one elongated elastic member,

d) applying a force on the electrical cable sufficient to produce a reaction force that deforms the elongated elastic member or members to a shape characterized by high mechanical energy such that deformed elastic member allows said electrical cable access to the sensitive volume at least partially surrounded by said monitoring instrument sensor,

e) applying additional force that positions the electrical cable to pass through the sensitive volume at least partially surrounded by said monitoring instrument sensor,

f) relaxing the force on the cable such that the resulting reactive force on the elongated elastic member or members allowing the elongated elastic member or members to relax to a shape characterized by lower mechanical energy than said high mechanical energy shape, and to apply elastic force to said electrical cable to hold the electrical cable passing through the sensitive volume firmly and securely in contact with the cable monitoring instrument with no relative motion,

g) disconnecting the hot stick from the mounting bracket,

h) Performing steps (a) through (g) in reverse order to remove electrical cable monitoring instrument from electrical cable.

14. The method for fastening to and removing from an electrical cable an electrical cable monitoring instrument of claim 13, where steps from b) through f) are performed as a united continuous action with no pose or delay during steps execution nor between the steps.

15. The method for fastening to and removing from an electrical cable an electrical cable monitoring instrument of claim 13 where the implementation of the attachment device is such that at least one force provided by the attachment device is in a direction which is opposed to the force of gravity.

16. The method for fastening to and removing from an electrical cable an electrical cable monitoring instrument of claim 13 where any action by external forces directed to produce relative motion, induces the attachment device to apply additional stabilization force or forces against the electrical cable resulting in action to prevent relative motion and further stabilize the device in secure contact with the electrical cable.