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US 4,068,280 AGranted
Automatic circuit restoration device for polyphase feed lines
OwnerPietro Basile, deceased, Maria Caligiuri, administratorinventors
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OwnerPietro Basile, deceased, Maria Caligiuri, administratorinventors
Estimating the term…
An automatic circuit restoration device for polyphase lines, comprising a set of normally open circuit breakers connected in series to respective feed lines and controlled in unison by one coil, and an auxiliary movable contact controlled by means responsive to the presence of voltage on one or more of the feed lines so that said movable contact is opened and said circuit breakers are closed through said coil when one of said feed lines is deenergized.
An automatic circuit breaker apparatus for polyphase electric systems having a plurality of feed lines associated with respective electric phases, which apparatus comprises a set of normally open main switching contacts connected in series to the respective feed lines and controlled in unison by one coil, and an auxiliary set of switching contacts controlled by means of responsive to the presence of voltage on one or more of the feed lines, said coil for controlling the set of main switching contacts, and said auxiliary switching contacts being connected in series between a first and a second one of said plurality of feed lines, said voltage responsive means including a coil having a movable core, with the terminals of said voltage responsive means coil being connected between one of said first and second feed lines and a third feed line, said movable core being adapted to maintain in a first position a movable plate that keeps said auxilliary set of switching contacts open said movable core retracting when said coil of voltage responsive means is energized to permit said movable plate to move by gravity to a second position for closing said auxiliary set of switching contacts.
Dependencies are inferred from the claim text.
Drawings are temporarily unavailable. Open the PDF at USPTO
No related US applications are recorded in the indexed filing history.
Emergency protective circuit arrangements for preventing the switching-on in case an undesired electric working condition might result: in case of…
Responsive to undervoltage or no-voltage: for multiphase applications, e.g. phase interruption
Emergency protective circuit arrangements
Term ended 10 Jan 1995 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
This invention relates to an automatic circuit restoration device that can be used for polyphase feed lines to open a set of circuit breakers in case of failure of one of the phases and for automatically restoring the circuit breakers to the closed position only when all phases are alive again.
U.S. Pat. No. 3,922,624 to Pietro BASILE discloses an automatic circuit restoring device for polyphase lines which, however, requires for its operation the provision of a neutral line and uses two separate relays.
It is the object of the present invention to overcome the limitations of this prior circuit restoration device by providing an automatic circuit restoration device for polyphase lines, capable of operation without the provision of a neutral line and having a more simple structure and consequently being less expensive to produce than the device described in the above patent.
A preferred embodiment of the invention will now be described by way of example and with reference to the accompanying drawing in which the single FIGURE shows a circuit diagram of the automatic circuit restoration device according to the invention.
Referring to the drawing, there is shown a three-phase alternating current feed system comprising three lines 10, 12, 14 and a set of circuit breakers or switches 16, 18, 20 controlled by a coil 22 for interrupting the lines.
The automatic circuit restoration device according to the invention comprises a solenoid having a winding 24 and a movable core 26 which, as seen in the drawing, extends upwardly when the winding is deenergized and is pulled downwardly by energization of the winding. Arranged above the core 26 is a movable plate 28 connected to a movable contact 30 adapted to establish and interrupt a connection between two poles 32, 34. As long as the winding 24 is deenergized, the core 26 keeps the movable plate 28 in the upper position and the plate 28 keeps the contact 30 open. However, when the core 26 is attracted by the winding 24, the movable plate 28 drops down under its own weight to close the contact 30.
The opposite ends of the winding 24 are connected through conductors 36, 38 to respective phase lines such as 12, 14, of the three-phase system so that the coil 24 will be energized only when both phases are present on the respective lines 12 and 14, but will be deenergized when one or both of these phases fail.