US3312918A - Remotely operated sealed circuit interrupter - Google Patents

Description

REMOTELY OPERATED SEALED CIRCUIT INTERRUPTER Filed Aug. 26, 1965 Ap 1967 J. .J. ASTLEFORD, JR, ETAL.

2 Sheets-Sheet l April 4, 1967 J. J. ASTLEFORD, JR, ETAL. 3,312,913

REMOTELY OPERATED SEALED CIRCUIT INTERRUPTER Filed Au 26, 1965 2 Sheets-Sheet 2 vdl INVENTORS Edward R Ronon 81 John Asi'leford r 36W ATTORNEY United States Patent i C) 3,312,918 REMOTELY OPERATED SEALED CIRCUIT INTERRUPTER John J. Astleford, Jr., Sharon, Pa., and Edward R. Ronan, Jr., Masury, Ohio, assignors to Westinghouse Electric Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Filed Aug. 26, 1965, Ser. No. 482,812 6 Claims. (Cl. 335-205) This invention relates to a circuit interrupter, and more particularly to a circuit interrupter for interrupting the primary or supply circuit of a transformer installed underground.

It is becoming common practice to install distribution transformers below the ground level. The transformers are usually installed in some type of vault or other enclosure. Whenever the transformer requires service it becomes necessary to interrupt the primary or supply voltage. The interrupter must not only provide electrical opening of the primary or supply circuit but must also provide a visual break in the circuit so that the service personnel can make sure by inspection that the primary 'or supply voltage to the transformer is positively interrupted before beginning service work on the transformer. Also, with underground installations, it is a common fault with circuit interrupters for the contacts to corrode or oxidize because of the moisture below the ground level and thereby cause rapid deterioration or breakdown of the circuit interrupter contacts.

It is an object of this invention to provide a completely enclosed circuit interrupter which provides a positive visible break in the circuit interrupted.

It is a further object of the present invention to pro vide a circuit interrupter wherein the interrupting contacts are enclosed in a transparent casing which is sealed against the outside atmosphere.

do not extend physically into the casing.

These and other objects are effected by this invention as will be apparent from the following description taken in accordance with the accompanying drawings, forming a part of this application, in which: FIGURE 1 is a vertical sectional view, taken along line II of FIG. 2, of the circuit interrupter provided by this invention; the contact structure being shown in the closed circuit position;

FIG. 2 is an inverted plan sectional view taken along line IIII of FIG. 1;

FIG. 3 is a partial vertical sectional view taken along line IIIIII of FIGS. 1 and 2; and,

FIG. 4 is a side elevational view of the circuit interrupter as provided by this invention showing means for operating the circuit interrupter exteriorly of the casing.

Referring to FIG. 1 of the drawing in detail, the circuit interrupter 9 provided by this invention comprises a transparent round sealed casing 10. The casing 10 comprises a round upper section 12 and a round lower section 14 which are fused or sealed together in some satisfactory manner along the line 16 after the circuit interrupter components have been installed in the parts 12 and 14.

' portion 18a.

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The lower portion 14 of the casing 10 has extending therethrough a conductor 18 providing a fixed pivot shaft The conductor 18 has'attached to the upper end thereof, and freely rotatable thereabout, a circuit making blade or movable contact arm 20. Also, mounted on the upper end of the conductor 18 and freely rotatable thereabout is mounted an actuating lever or arm 22. The lever 22 has a pin 24 therein near its outer end and the circuit making and breaking blade 20 also has a pin 26 therein intermediate its ends. Overcenter spring actuating means 25 including an overcenter tension spring 28 is connected between the pins 24 and 26. A barium ferrite permanent magnet 30 is attached to the outer end of the lever or actuating arm 22 by means of a pin 32.

The upper part 12 of the casing 10 has extending therethrough a conducting element 34. The conducting element 34 is connected by means of a strap conductor 36 to a jaw-type stationary contact including a pair of stationary contact fingers 38. The stationary contact 37 is afiixed to the conducting strap 36 and to the upper part 12 of the housing 10 by means of a screw 40. The stationary contact 37 is fixedly mounted in the upper part 12 of the housing 10 on an integral supporting portion 39 of the sectional part 12 of the housing 10 and does not rotate.

The elements described hereinbefore have been mounted in the respective portions of the casing 10. The parts 12 and 14 of the casing 10, which are made of a transparent plastic or glass, are sealed together along the line 16. After the two parts 12 and 14 of the casing 10 have been sealed together, the casing is evacuated of air through the tip-off tube 44. After the air has been pumped out of the casing 10, the inside of the casing 10 is flushed, or filled with a gaseous electronegative fluorine containing compound, such as sulfur hexafluoride (SF gas, selenium hexafluoride (SEF gas, or trifluoro-methyl sulfur hexafluoride (CF SF gas to maintain contact erosion and the products of decomposition during arcing of the contacts at a minimum. After the casing 10 has been filled with the gaseous electronegative fluorine-containing compound, the casing is hermetically sealed by tipping off the tube 44.

The circuit interrupter 9 provided by this invention is intended for use in a primary or supply voltage lines of the transformer (not shown) mounted underground. Such a circuit breaker 9 is required to interrupt voltages of the order of magnitude of 15 ,000 volts.

The interrupter 9 provided by this invention is intended to be mounted either directly upon a high voltage transformer bushing (not shown), or if the bushing is not designed to receive the interrupter, the interrupter 9 may be mounted on a wall, or other support by means of a strap bracket 46 as shown in FIG. 2.

The interrupter shown and described herein has an opening 48 provided in the lower part of the portion 14 of the casing 10. The opening 48 is lined with a molded rubber portion 50 to provide a water-tight seal between the circuit interrupter 9 and the high voltage bushing of the transformer or a connector attached to the high voltage line. Although the liner 50 is shown herein as being composed of rubber it is understood that it may be made of any'other suitable material which will provide a waterto a hollow cylindrical contact member 58. It is to be observed that the upper end of the insulation on the cable 52 is tapered, as at 59, to complement the tapered inside of the liner 50. When the circuit interrupter 9 is installed on the end of the cable 52, the conductor member 18 of the circuit interrupter 9 fits into the hollow cylindrical member 58 and makes good electrical connection there.- with. The tapered upper end of the cable 52 is forced into the tapered opening 59 in the liner 50, and makes a water-tight connection therewith; Although FIG. 1 illustrates the circuit interrupter 9 attached to the end of a g -V ltage cable 52, it is to be understood that it may be attached directly to a high voltage bushing of a transformer in the same manner, the only difference being that the end of the high voltage bushing of the transformer would have to be shaped to fit into the tapered opening 59 in the liner 50 in the end of the circuit interrupter 9.

The upper portion 12 of the casing 10 is provided with a conical portion 60. The conducting member 34 extends through the conical portion 60 of the upper portion 12 of the casing 10, and the upper end of the conductor 34 is drilled out to provide a tubular portion 34a. A high voltage or primary cable 64 is shown attached to the conductor 34. The cable 64 comprises insulation 66 and an electrical conductor 68. The end of the cable 68 is provided with a conical cavity or recess 70, which has the same shape as the conical portion 60 of the upper portion 12 of the casing 10. To make electrical connection between the electrical conductor 68 and the upper portion of the circuit interrupter 9 the cable 64 is forced over the conical portion 60 of the circuit interrupter 9 and the conductor 68 of the cable 64 is forced into the tubular portion 34a of the conductor 34 and makes good frictional electrical contact therewith.

Although the high voltage cables 52 and 64 have been described with different reference numerals it is understood that these two conductors 52 and 64 may be the same cable with the adjacent ends of the insulation shaped for the insertion of the circuit interrupter 9 therebetween.

The casing 10 is provided with a molded shoulder or stop 76, which serves to stop the operating lever or actuating arm 22 when the circuit making blade or element is in closed circuit position, and is likewise provided with a molded shoulder or stop 78 which serves as a stop for the lever 22 when the lever 22 is in an open circuit position. Likewise, the casing is also provided with a molded stop or shoulder 80 which serves as a stop for the circuit making and breaking blade or element 20 when the circuit interrupter is in open circuit position.

As seen from FIG. 4 the outside of the casing 10 is marked with On and Off positions. The On position represents the closed circuit position of the circuit interrupter 9 and the Off position represents the open circuit position of the circuit interrupter. Assume that the circuit interrupter is in On circuit position, to open the circuit an operator would use a stick 82 which has a barium ferrite permanent magnet 84 attached to the end thereof. He would place the stick adjacent the On circuit indication on the casing 10 and gradually move the stick around the casing 10 to the open circuit position, or the Off position on the casing 10. As the stick is moved along the casing 10 from the On to the Off position, the barium ferrite magnet 84, which would be poled oppositely to the barium ferrite magnet 30, would pull the lever 26 around to the Off position thus loading the spring 28, which at some predetermined position would snap the circuit making blade or element 20 from between the circuit making finger contacts 38 and thus break the circuit. The stop 80 would limit the movement of the circuit'making and breaking blade or element 20. When the magnet 30 has been moved to the Off position on the casing 10, the circuit making and breaking element 20 will be snapped from between the circuit making contacts 28 and will come to rest against the stop 88. In this position, one can see through the transparent casing 10 and make sure that the circuit is broken. In

ther words, a visual break is made in the high voltage primary circuit in which the circuit interrupter 9 is inserted. This position of the circuit making and breaking element 20 is illustrated by the broken line illustration of the element 20 in FIG, 2. Likewise, to close the circuit interrupter, the magnet 84 is placed adjacent the Off position on the case 10 and slowly moved along the casing 10 to the On position, at which position the spring 28 will be sufficiently loaded to snap the movable circuit making and breaking blade or element 20 in between the contact fingers 38 and close the circuit. In this position, the operator may also visually inspect the circuit because of the transparent casing 10 to make sure that the circuit is again closed. This position of the circuit making and breaking element 20 is illustrated by the solid line illustration of the blade 20 in FIG. 2. Thus magnetic means 86, comprising the two permanent magnets 30, 84, is utilized to effect opening and closing operations of the circuit interrupter 9.

From the foregoing description, it is seen that this invention has provided a high voltage load break circuit interrupter 9 for interrupting the high voltage of a primary line of a transformer, wherein the circuit interrupter is enclosed in a sealed-transparent casing 10 which permits operation of the circuit making and breaking element without having any levers or operating mechanisms extending through the casing, and the position of the circuit making and breaking element may be visually inspected to insure that the circuit is either open or closed, according to the position of the operating mechanism. Because all of the elements of the circuit maker and breaker provided by this invention is enclosed in a sealed casing with no operating mechanisms extending therefrom, this invention provides a circuit maker and breaker which may be operated submerged under liquid.

There are no moving seals or operating mechanisms extending through the casing, which thereby permits water-tight sealing of the casing. All join-ts to the circuit maker and breaker are also made with water-tight seal connectors. Also, the snap-acting contacts 20, 37 are operated in pressurized electronegative gas which accomplishes arc quenching in a small volume without the use of oil or other liquid dielectrics.

From the foregoing description taken in connection with the drawings, it is seen that the invention described herein has provided a new and improved sealed circuit interrupter 9 for interrupting high-voltage load circuits, which provide positive circuit interruption wherein the condition of the circuit interrupted may be visually inspected without having parts of the energized circuitexposed, where they may be inadvertently contacted by servicing personnel. The invention described herein also provides a circuit interrupter which may be easily installed with water-tight seals for operating under submerged con ditions.

While the invention has been shown in only one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof.

We claim as our invention:

'1. A circuit interrupter comprising a sealed casing, means defining a stationary contact mounted interiorly of said sealed casing, first conductor means electrically connected to said stationary contact and extending exteriorly of said sealed casing, second fixed conductor means extending interiorly of said sealed casing and providing a fixed pivot shaft portion, said fixed pivot shaft portion freely rota-tably supporting a movable contact arm carrying a movable contact adjacent the free end thereof, said movable contact being cooperable with said stationary contact to open and close the connected circuit, overcenter spring actuating means including a rotatable actuating arm also freely rotatably supported on said fixed pivot shaft portion, said overcenter spring actuating means further including an overcenter tension spring with its ends secured to both said movable contact arm and said rotatable actuating arm, said actuating arm and said movable contact arm having opposite rotative opening and closing movement whereby said overcenter spring moves over said pivot shaft portion, and magnetic means including an externally movable magnetic member and a following internal member secured to said actuating arm for eifecting snap opening and closing movement of said movable contact member.

2. The circuit interrupter according to claim 1, wherein said following internal member secured tot-he actuating arm is a permanent magnet.

3. The circuit interrupter according to claim 1, wherein the sealed casing is formed of transparent material so that one may actually view the open and closed circuit positions of the interrupter.

4. The circuit interrupter according to claim 1, wherein the sealed casing has a gaseous electronegative fluorine containing compound disposed therein.

5. A circuit interrupter comprising a transparent hermetically sealed casing, a fixed contact mounted inside said casing, first conductor means connected to said fixed contact and extending exteriorly of said casing for electrically connecting anelectrical conductor to said fixed contact, said casing having a conical portion around said first conductor means to permit making a water tight connection from an electrical conductor to said first conductor means, a movable circuit opening and closing element in said'casing, second conductor means connected to said movable circuit opening and closing element and extending exteriorly of said casing for electrically connecting an electrical conductor to said movable circuit opening and closing means, said casing terminating in a hollow conical shaped configuration around said second conductor means, arubber gasket in said conical hollow portion of said casing, said rubber gasket providing a water tight connection between said second conductor means and an electrical conductor, pivoted lever means in said casing, spring means connected between said movable circuit opening and closing element and said pivoted lever means, a permanent magnet mounted adjacent one end of said pivoted lever means, said permanent magnet being located adja cent to a side of said casing, said permanent magnet being movable from the exterior of said casing to move said pivoted lever means and load said spring to move said movable circuit opening and closing element to either of the predetermined circuit opening or circuit closed positions, said circuit opening and closing element being visible through said transparent casing.

6. A circuit interrupter comprising a transparent hermetically sealed casing, a fixed cont-act mounted inside said casing first conductor means connected to said fixed contact and extending exteriorly of said casing for electrically connecting an electrical conductor to said fixed contact, means for making a water tight connection between said first conductor means and an electrical conductor, a movable circuit opening and closing element in said casing, second conductor means connected to said movable circuit opening and closing element and extending exteriorly of said casing for electrically connecting an electrical conductor to said movable circuit opening and closing element, means for making a water tight connection between said second conductor means and an electrical conductor, a lever pivotally mounted in said casing, spring means connected between said movable circuit opening and closing element and said pivoted lever, permanent magnet means mounted adjacent an end of said lever, said permanent magnet means being positioned adjacent to an outside wall of said casing, said casing being filled with an electronegat-ive gas and hermetically sealed, said permanent magnet being movable by means exteriorly or" said casing to load said spring to cause said movable contact member to move to predetermined circuit opening and circuit closing positions, said circuit opening and closing element being visible through said transparent casing.

References (Iited by the Examiner UNITED STATES PATENTS 561,581 5/1896 Guett 200-67 2,012,153 8/1935 Bates 200-87 X 2,306,585 12/1942 Appelberg 200 87 2,649,712 8/1953 Dale 200-87 X 3,200,214 8/1965 Aubert 200-87 X BERNARD A. GILHEANY, Primary Examiner. J. BAKER, Assistant Examiner.

Claims (1)

1. A CIRCUIT INTERRUPTER COMPRISING A SEALED CASING, MEANS DEFINING A STATIONARY CONTACT MOUNTED INTERIORLY OF SAID SEALED CASING, FIRST CONDUCTOR MEANS ELECTRICALLY CONNECTED TO SAID STATIONARY CONTACT AND EXTENDING EXTERIORLY OF SAID SEALED CASING, SECOND FIXED CONDUCTOR MEANS EXTENDING INTERIORLY OF SAID SEALED CASING AND PROVIDING A FIXED PIVOT SHAFT PORTION, SAID FIXED PIVOT SHAFT PORTION FREELY ROTATABLY SUPPORTING A MOVABLE CONTACT ARM CARRYING A MOVABLE CONTACT ADJACENT THE FREE END THEREOF, SAID MOVABLE CONTACT BEING COOPERABLE WITH SAID STATIONARY CONTACT TO OPEN AND CLOSE THE CONNECTED CIRCUIT, OVERCENTER SPRING ACTUATING MEANS INCLUDING A ROTATABLE ACTUATING ARM ALSO FREELY ROTATABLY SUPPORTED ON SAID FIXED PIVOT SHAFT PORTION, SAID OVERCENER SPRING ACTUATING MEANS FURTHER INCLUDING AN OVERCENTER TENSION SPRING WITH ITS ENDS SECURED TO BOTH SAID MOVABLE CONTACT ARM AND SAID ROTATABLE ACTUATING ARM, SAID ACTUATING ARM AND SAID MOVABLE CONTACT ARM HAVING OPPOSITE ROTATIVE OPENING AND CLOSING MOVEMENT WHEREBY SAID OVERCENTER SPRING MOVES OVER SAID PIVOT SHAFT PORTION, AND MAGNETIC MEANS INCLUDING AN EXTERNALLY MOVABLE MAGNETIC MEMBER AND A FOLLOWING INTERNAL MEMBER SECURED TO SAID ACTUATING ARM FOR EFFECTING SNAP OPENING AND CLOSING MOVEMENT OF SAID MOVABLE CONTACT MEMBER.

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