Method and apparatus for side leg utility conveyance
First Claim
1. A method for selectively applying a particular one of a plurality of different frequency conveyance-locating signals to each of a plurality of short-haul buried utility conveyances, each coupled between a common long haul buried utility conveyance and ground, comprising the steps of:
- applying to the long haul conveyance the plurality of different frequency conveyance locating signals, and passively filtering, via a notch filter on each short haul conveyance, the plurality of different frequency locating signals to pass only a particular frequency locating signal unique to that short haul conveyance.
1 Assignment
0 Petitions
Accused Products
Abstract
To locate via electromagnetic signaling each of a plurality of buried side leg conveyances (141-146) coupled to a common underground backbone conveyance (12), a cable locating signal generator (17) applies a plurality of different frequency conveyance locating signals to the backbone conveyance. A separate one of a plurality of filter arrestors (181-186) selective passes a particular one of the plurality of different frequency locating signals onto a corresponding one of the side leg conveyances. In this way, each side leg conveyance carries only a particular frequency locating signal whose strength remains unaffected by the locating signal on the other side leg conveyances.
10 Citations
6 Claims
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1. A method for selectively applying a particular one of a plurality of different frequency conveyance-locating signals to each of a plurality of short-haul buried utility conveyances, each coupled between a common long haul buried utility conveyance and ground, comprising the steps of:
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applying to the long haul conveyance the plurality of different frequency conveyance locating signals, and passively filtering, via a notch filter on each short haul conveyance, the plurality of different frequency locating signals to pass only a particular frequency locating signal unique to that short haul conveyance. - View Dependent Claims (2, 3, 4)
the step of applying to the long haul conveyance the plurality of different frequency conveyance locating signals includes the step of applying at least a first frequency conveyance locating signal and a second frequency conveyance locating signal; and
the step of passively filtering the plurality of different frequency locating signals includes passing the first frequency locating signal on a first short haul conveyance, and passing the second frequency locating signal on a second short haul conveyance.
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5. A method for locating each of a plurality of short-haul buried utility conveyances, each coupled between a common long haul buried utility conveyance and ground, comprising the steps of:
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applying to the long haul conveyance a plurality of different frequency conveyance locating signals;
passively filtering, via a notch filter on each short haul conveyance, the plurality of different frequency locating signals to pass only a particular frequency locating signal unique to that short haul conveyance; and
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detecting the particular frequency locating signal passed on said each short haul conveyance to locate the conveyance.
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6. Apparatus for selectively applying a particular one of a plurality of different frequency conveyance-locating signals to each of a plurality of short-haul buried utility conveyances, each coupled between a common long haul buried utility conveyance and ground, comprising:
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a cable locating signal generator for applying to the long haul conveyance the plurality of different frequency conveyance locating signals, and a notch filter on each short haul conveyance for passing through that conveyance only a particular frequency locating signal unique thereto.
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Specification
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- Resources
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Current AssigneeAT&T Corporation (AT&T, Inc.)
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Original AssigneeAT&T Corporation (AT&T, Inc.)
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InventorsKirkpatrick, James F, Huffman, John Sinclair, Eslambolchi, Hossein
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Primary Examiner(s)Le, N.
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Assistant Examiner(s)Kinder, Darrell
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Application NumberUS10/078,686Time in Patent Office742 DaysField of Search324/67, 324/326, 324/329, 324/529, 324/66, 361/111, 361/119, 361/120, 379/28US Class Current324/326CPC Class CodesG01V 3/081 the magnetic field is produ...
