US3803484A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for measuring deterioration in a shielded cable by high frequency pulse injection
Assignee: United States Department of the Army
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Filing: 1972-11-30
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Granted: 1974-04-09
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Expires: 1992-11-30
Abstract
Abstract A generator injects a current pulse to a coaxial driver that is slipped over one end of a shielded cable undergoing test. The current pulse is divided between the cable shield and the cable bundle. A capacitive trough is positioned along an intermediate length of the cable, adjacent the cable shield, and serves as a high-frequency current return. Remaining low frequency current is returned through the total length of the cable. Instrumentation is provided to compare the ratio of the internal bundle current to the external shield current with known standards, over a frequency spectrum thereby permitting the detection of connector and cable deterioration.
Inventors
- 👤 R Gray
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:45
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/08; G01R31/50; G01R31/58
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
92 words
A method for testing a shielded cable consisting of the steps of: subjecting the shield of the cable and the Internal conductors thereof to an input current pulse; measuring the conductor current amplitude as a function of frequency; measuring the input current amplitude as a function of frequency; forming a ratio relationship between conductor current and input current at particular frequencies thereby defining the cable transfer function; and comparing the transfer function of the tested cable with that of known standard cable, deviations between the transfer functions being determinative of cable deterioration.
Claim 2
Independent Claim
92 words
A method for testing a shielded cable consisting of the steps of: subjecting the shield of the cable and the Internal conductors thereof to an input current pulse; measuring the conductor current amplitude as a function of frequency; measuring the input current amplitude as a function of frequency; forming a ratio relationship between conductor current and input current at particular frequencies thereby defining the cable transfer function; and comparing the transfer function of the tested cable with that of known standard cable, deviations between the transfer functions being determinative of cable deterioration.
Claim 3
Independent Claim
129 words
A system for testing a shielded cable having connectors at opposite ends thereof, the system comprising: means for generating an input current pulse; conductor means for conducting the input current pulse to at least one internal conductor and the cable shield via a first connector; means for separately measuring the input current and the current flowing through the internal conductor as a function of frequency to enable the determination of the ratio of internal conductor current to input current for particular frequencies thereby defining a cable transfer function to be compared with a standard cable function; and means for completing a return circuit path from the internal conductor and the shield, via a second connector to the generating means; deviations between the transfer functions being indicative of cable deterioration.
Claim 4
Independent Claim
129 words
A system for testing a shielded cable having connectors at opposite ends thereof, the system comprising: means for generating an input current pulse; conductor means for conducting the input current pulse to at least one internal conductor and the cable shield via a first connector; means for separately measuring the input current and the current flowing through the internal conductor as a function of frequency to enable the determination of the ratio of internal conductor current to input current for particular frequencies thereby defining a cable transfer function to be compared with a standard cable function; and means for completing a return circuit path from the internal conductor and the shield, via a second connector to the generating means; deviations between the transfer functions being indicative of cable deterioration.
Claim 5
Dependent Claim
47 words
The structure of claim 2 wherein the cable includes a plurality of internal conductors to form a cable bundle, and further wherein means are provided to short circuit the individual conductors at both ends of the bundle to enable parallel conduction of current through the individual conductors.
Claim 6
Dependent Claim
30 words
The structure as defined in claim 2 wherein a high frequency driver is coaxially mounted over a cable end, the driver being connected between the generator and the cable shield.
Claim 7
Dependent Claim
55 words
The structure of claim 2 together with a capacitive trough located adjacent an intermediate length of the cable shield; and means for connecting the trough to the generator to complete a high frequency current bypass to the generator, the remaining low frequency current being conducted along the entire length of the shield and the conductor.
Claim 8
Dependent Claim
27 words
The subject matter defined in claim 2 wherein the cable is looped while undergoing testing to improve the wide frequency bandwidth of current conduction through the cable.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-08 | 1977-10-08 | 1978-04-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-08 | 1981-10-08 | 1982-04-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-08 | 1985-10-08 | 1986-04-09 | $7700.00 | Window Closed / Lapsed |