Claims
- 1. An article for electronically marking a buried conduit, comprising:
- a plurality of electronic markers having longitudinal axes;
- tether means maintaining a spacing of said markers at predetermined intervals, said predetermined intervals forming a known pattern which encodes information about the buried conduit, and said axes of said markers being successively oriented in a predetermined pattern which encodes additional information about the buried conduit; and
- means attaching said markers to said tether means at said predetermined intervals.
- 2. The article of claim 1 wherein said electronic markers are passive, having a coil of wire connected in parallel with a capacitor, forming a resonant circuit.
- 3. An article for electronically marking a buried conduit, comprising:
- a plurality of electronic markers having longitudinal axes;
- tether means maintaining said markers with their respective axes successively oriented in a predetermined pattern, said pattern encoding information about the buried conduit; and
- means attaching said markers to said tether means.
- 4. A marker tape for placement adjacent to a buried conduit, comprising:
- a nonconductive tether which is color-coded according to the particular type of conduit to be marked;
- a plurality of passive electronic markers each having a coil of wire connected in parallel with a capacitor, forming a resonant circuit, and having longitudinal axes; and
- means attaching said markers to said tether, said markers being spaced along said tether at predetermined intervals, said predetermined intervals forming a known pattern which encodes information about the buried conduit, and said axes of said markers further being successively oriented in a predetermined pattern which encodes additional information about the buried conduit.
- 5. The marker tape of claim 4 wherein said passive electronic markers are generally planar and said tether comprises a tape ribbon.
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of copending U.S. patent application Ser. No. 07/409,523 filed Sept. 18, 1989 now U.S. Pat. No. 5,017,415.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
4767237 |
Cosman et al. |
Aug 1988 |
|
5006806 |
Rippingdale |
Apr 1991 |
|
5017415 |
Cosman et al. |
May 1991 |
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Foreign Referenced Citations (1)
Number |
Date |
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9000748 |
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WOX |
Continuations (1)
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Number |
Date |
Country |
Parent |
409523 |
Sep 1989 |
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