US3708724A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Signalling system responsive to fault on electric power line
Assignee: EO Schweitzer Manufacturing Co LLC
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Filing: 1972-03-31
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Granted: 1973-01-02
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Expires: 1992-03-31
Abstract
Abstract One or more reed switches have contacts that are held closed on normal energization or current flow in an alternating current conductor and are opened on flow of alternating current in the conductor above a predetermined value. The switch or switches may be potted in a cavity in an insulator supporting the conductor. A rectifier energized from the conductor charges a capacitor the discharge from which through winding means effects closure of the contacts.
Inventors
- 👤 E Schweitzer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:43
CPC Classifications
G; G01; G01R; G01R19/00; G01R19/165; G01R19/16504; G01R19/16509; H; H01; H01H; H01H71/00; H01H71/10; H01H71/12; H01H71/24; H01H71/2445
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
182 words
A signalling system for an alternating current conductor energized at a relatively high voltage above ground comprising: a reed switch containing a pair of magnetic contacts spring biased to one position for connection to a signalling circuit, a relatively low coercive force U-shaped magnetic core with the arms extending along the lines of alternating magnetic flux surrounding said conductor and generated by flow of alternating current in said conductor and their distal ends adjacent the terminals of said contacts of said reed switch, magnetizing winding means on said core, a trigger circuit, a capacitor connected in series with said trigger circuit and across said magnetizing winding means, rectifier means connected to charge said capacitor, and circuit means for electrostatic connection between said conductor and ground for energizing said rectifier means, said trigger circuit periodically discharging said capacitor through said winding means to magnetize said core and hold said contacts in another position, said core being demagnetized by said alternating magnetic flux around said conductor on flow therethrough of alternating current above a predetermined value to shift said contacts to said one position.
Claim 2
Dependent Claim
182 words
A signalling system for an alternating current conductor energized at a relatively high voltage above ground comprising: a reed switch containing a pair of magnetic contacts spring biased to one position for connection to a signalling circuit, a relatively low coercive force U-shaped magnetic core with the arms extending along the lines of alternating magnetic flux surrounding said conductor and generated by flow of alternating current in said conductor and their distal ends adjacent the terminals of said contacts of said reed switch, magnetizing winding means on said core, a trigger circuit, a capacitor connected in series with said trigger circuit and across said magnetizing winding means, rectifier means connected to charge said capacitor, and circuit means for electrostatic connection between said conductor and ground for energizing said rectifier means, said trigger circuit periodically discharging said capacitor through said winding means to magnetize said core and hold said contacts in another position, said core being demagnetized by said alternating magnetic flux around said conductor on flow therethrough of alternating current above a predetermined value to shift said contacts to said one position.
Claim 3
Dependent Claim
20 words
Signalling system according to claim 1 wherein a hollow insulator for supporting said conductor has said signalling system enclosed therein.
Claim 4
Dependent Claim
15 words
Signalling system according to claim 1 wherein said contacts are spring biased to open position.
Claim 5
Dependent Claim
23 words
Signalling system according to claim 1 wherein the longitudinal axis of said reed switch is transverse to the longitudinal axes of said arms.
Claim 6
Dependent Claim
21 words
Signalling systeM according to claim 1 wherein said magnetizing means comprises a winding on one of said arms of said core.
Claim 7
Dependent Claim
19 words
Signalling system according to claim 1 wherein said magnetizing means comprises a winding on each arm of said core.
Claim 8
Dependent Claim
32 words
Signalling system according to claim 1 wherein said trigger circuit includes gated semiconductor means shunted by a space discharge device rendered conducting when the charge on said capacitor reaches a predetermined value.
Claim 9
Dependent Claim
56 words
Signalling system according to claim 1 wherein circuit means interconnect said reed switch and said rectifier means to discharge said capacitor when said contacts occupy said other position to prevent application of repeated magnetizing pulses to said winding means from said capacitor, said magnetic core having sufficient retentivity to hold said contacts in said other position.
Claim 10
Dependent Claim
158 words
A signalling system for an alternating current conductor energized at a relatively high voltage above ground comprising: reed switch means containing at least one pair of magnetic contacts spring biased to one position for connection to a signalling circuit and for location adjacent said conductor with the longitudinal axis along the lines of magnetic flux surrounding said conductor generated by flow of alternating current in said conductor, a permanent magnet adjacent the terminals of said contacts and biasing them toward another position, winding means adjacent said reed switch means, and means for energization from said conductor for energizing sad winding means with direct current to assist said permanent magnet means in shifting said contact means to said other position, the magnetic fields from said permanent magnet and said winding means being reduced by said alternating magnetic flux around said conductor on flow therethrough of alternating current above a predetermined value to shift said contacts to said one position.
Claim 11
Dependent Claim
158 words
A signalling system for an alternating current conductor energized at a relatively high voltage above ground comprising: reed switch means containing at least one pair of magnetic contacts spring biased to one position for connection to a signalling circuit and for location adjacent said conductor with the longitudinal axis along the lines of magnetic flux surrounding said conductor generated by flow of alternating current in said conductor, a permanent magnet adjacent the terminals of said contacts and biasing them toward another position, winding means adjacent said reed switch means, and means for energization from said conductor for energizing sad winding means with direct current to assist said permanent magnet means in shifting said contact means to said other position, the magnetic fields from said permanent magnet and said winding means being reduced by said alternating magnetic flux around said conductor on flow therethrough of alternating current above a predetermined value to shift said contacts to said one position.
Claim 12
Dependent Claim
22 words
Signalling system according to claim 9 wherein said reed switch means comprises a pair of reed switches connected in series circuit relation.
Claim 13
Dependent Claim
33 words
Signalling system according to claim 10 wherein a magnetic shunt is located adjacent corresponding ends of said reed switches, and said permanent magnet is located adjacent the other ends of said reed switches.
Claim 14
Dependent Claim
46 words
Signalling system according to claim 9 wherein the biasing action of said permanent magnet is less than that required to shift said contacts to said other position, and said winding means surrounds said reed switch and when energized shifts said contact means to said other position.
Claim 15
Dependent Claim
53 words
Signalling system according to claim 9 wherein said means for energizing said winding means comprises rectifier means energized by alternating current derived from said conductor to charge a capacitor connected in series with a space discharge device across said winding means and rendered conducting when said capacitor is charged to a predetermined value.
Claim 16
Dependent Claim
29 words
Signalling system according to claim 13 wherein said rectifier means is energized from the secondary winding of a transformer the primary winding of which is energized from said conductor.
Claim 17
Dependent Claim
19 words
Signalling system according to claim 13 wherein said rectifier means is energized through electrostatic connecting means from said conductor.
Claim 18
Dependent Claim
54 words
Signalling system according to claim 9 wherein said means for energizing said winding means comprises rectifier means energized by alternating current derived from said conductor to charge a capacitor connected in series with gated semiconductor means triggered by a space discharge device rendered conducting when the charge on said capacitor reaches a predetermined value.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-02 | 1976-07-03 | 1977-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-02 | 1980-07-03 | 1981-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-02 | 1984-07-03 | 1985-01-02 | $7700.00 | Window Closed / Lapsed |