US1923323A - Repeater circuit breaker - Google Patents

Description

Aug. 22, 1933.

J. P. MEDLIN 1,923,323

REPEATER CIRCUIT BREAKER 1 Filed Aug. 9, 1930 3 Sheets-Sheet 1 J E? M A M 7 Aug. 22,1933. J, E'D 1,923,323

REPEATER C IRCUI T BREAKER -Filed Aug. 9, 1930 3 Sheets-Sheet 2 Aug. 22, 1933. J. P. MEDLIN REPEATER CIRCUIT BREAKER Filed Aug. 9, 1930 3 Sheets-Sheet 3 bar-d gwuwdoz:

Patented Aug. 22, 1933 UNITED STATES BEPEATER omcurr BREAKER John P. Medlin, Great Falls, Mont., assignor to Railway & Industrial Engineering Company, Greensburg, Pa., a Corporation of Pennsylvania Application August 9, 1930. Serial No. 474,204

12 Claims. (Cl. 200 -126) This invention relates to a circuit breaker and particularly to a repeating circuit breaker actuated by an explosive fuse.

In the art of clearing high tension electric circuits of overloads by breaking the circuit, it has been .desired to have. a circuit breaker which is simple and inexpensive to manufacture, but which is certain and rapid in operation whereby the circuit may be opened in the least possible time after the occurrence of the overload. Circuit breakers having a sufficiently rapid operation have heretofore been constructed but they have been complicated in structure and consequently very expensive to manufacture.

One of the objects of the present invention is to provide a circuit breaker which will be readily responsive to an overload in a circuit and which will break the circuit very quickly after such overload occurs.

Another object of the invention is to provide a circuit breaker of the quick-acting type which will be simple, rugged, and inexpensive'to manufacture.

Another object of the invention is the provision of a circuit breaker actuated by an explosive fuse and provided with a repeating fuse holder carrying a plurality of fuses whereby the circuit may be opened a plurality of times without the necessity for manually resetting or replacing any members.

Still another objectof the invention is the provision of a repeating circuit breaker wherein is provided a time-delay mechanism for preventing the reclosing of the circuit for predetermined time after the opening thereof.

Inthe drawings: F r

Fig. 1 is a side elevational view, partly in crosssection, showing the circuit breaker;

Fig. 2 is an end elevational view; partly in crosssection of the same structure;

Fig. 3 is a detail view partly in cross-section showing the actuating mechanism;

Fig. 4' is a view of a section taken along line '4--4 of Fig. 3;

Figs. 5 and 6 are views taken along line 5-5 and 6-6, respectively of Fig. 1; and

Figs. '7 to 10 are fragmentary views showing details.

The circuit breaker is mounted on a base-plate 1 formed of insulating material, such as phenolic condensate, which base-plate is secured to the top of an insulator 2, carried on a supporting frame 3. Secured on the top surface of the base-plate is a cup-shaped base 4 of brass, or similar material, 55 in which is inserted the lower end of an oil-filled tank 5 constructed of insulating material, the top of which is closed by a brass cap 6 similar to the base 4.

The cap 6 carries a guide frame comprising a top plate '7, a bottom plate 8, a plurality of parallel side members 9 extending between the circumferential portions of the top and bottom plates and a plurality of parallel guide rods 10 extending between the plates '7 and 8. A second insulator 11 mounted on the supporting frame 3, carries a strap 12 which is secured to certain of the side members9, intermediate their ends, thus providing means for securing the upper end of the circuit breaker structure. The strap 12 also serves as a terminal member to which one side 7 of the line may be connected.

Secured to the base 1, inside of the oil tank 5 is a pair of. opposed contact springs forming a switch jaw 13. A movable switch blade 14, dieposed axially in said oil tank 5, depends from a head 15 arranged to reciprocate vertically in the guide rods 10. The lower end of the blade 14 is arranged to move into contact with the jaw 13, and to be engaged thereby.

Cooperating with the head 15, is a. push rod 16 which extends parallel to and along the outside of the oil tank 5. The push rod 16 is secured by nieans of a pivot to an operating lever 17 which is itself pivotally supported in a fulcrum member 18 mounted on the base-plate 1, and normallyurged in a clockwise direction by aspring 1'7.

-A revolver, which forms one of the principal elements of the actuating means, comprises ahollow pillar 19 upon which a fuse cylinder 20 is mounted for rotation in a horizontal plane. The fuse cylinder 20 is in the form of a short cylindrical block having a plurality of chambers 21 extending axially therethrough and equally spaced circumferentially of the block. A coiled spring 22 having one end anchored to the pillar 19 andthe other end attached to the fuse cylinder 20 is disposed within the pillar 19 for the purpose of rotating the cylinder 20. Disposed in each of the chambers 21 is an explosive cartridge fuse 23 of a type generally similar to that shown and described in detail in my copending application, Serial Number 370,709, filed June 13, 1929. Each fuse 23 comprises a cas- 105 ing 24 in which is disposed a projectile 25 and an ignition wire 26, surrounded by an explosive material 27. A recoil disk 28, disposed .over the ends of the fuses 23 to prevent them from moving upwardly when discharged, is secured in place by no a wing nut threaded on a bolt extending from the base of the pillar 19. The recoil disk 2&3 may be readily removed for replacement of ex ploded fuses.

Disposed beneath the fuse block coaxial with each chamber is a hollow metallic projectile cyl inder 29 insulated from the block by an insulating washer 30. The lower end or" the fuse casing 24 is disposed in the cylinder and the projectile 25 extends downwardly from the cylinder 29 to such an extent that, when the chamber is directly above the free end of the operating lever, the end of the projectile 25 bears against the side flange 31 of the lever 17 whereby rotation of the block Szll is prevented.

soft metal brush 32 is supported on the base.

nal member and is arranged e wall of the block 25. A similar brns. ed a second terminal 35, is arranged to bear against that projectile cylinder 29 which directly ae the free end of the l7, and a resilient per 36 is carried by the projectile cylinder 29 contacts with the projectile 25. econd j 37 connects the second terminal with t tank. base The head 15, shown in det in Figs. 9 and it, carried at the upper end of tile switch blade 14, is substantially rectangular in longitudinal crosssection and has a portion of its lower, outer corner cut away to provide space for a guide 38 formed integral with the bottom plate, in which guide the push rod reciprocates. lln impactsurface, or anvil 39 is formed on under side of this cut away portion for cooperation with the upper end of the push rod. A plurality or" lugs 40 on plate by a te' to agai the head cooperate slidably with the guide rods 10 to position the head 15 for reciprocation thereon. A flexible jumper 41 provides electrical connection between the head 15 and the upper terminal 12.

The head 15 is provided with an opening 42 extending therethrough to form a loop 43 for cooperation with a time relay latch which is shown in detail in Figs. 7 and 8. Secured to a gear wheel 44 is an arm 45 which is normally maintained in an upwardly inclined position by means of a spring 46 and which arm carries a pawl 47 arranged to move upwardly with respect to the arm 45, but not downwardly. A. pinion 48 meshing with the gear wheel 44 is secured to'a second gear 49 which in turn drives a worm wheel 50. A worm 51, which meshes with the worm wheel, is carried by the upper end of a vertical governor shaft 52 upon which is mounted a flyball governor 53.

The device is well protected from moisture and dirt by means of a plurality of casings formed of insulating material. One casing 54 surrounds the push rod. Mounted on the base-plate is another casing 55 which covers the revolver and is provided with a portion fitted around the lower portion of the oil tank 5. A third casing 56 surrounds the guide members and a fourth casing 57 is telescoped over the top end of the device to serve as a cover.

The electric circuit through the device may be traced as follows: From the upper terminal 12 through the flexible jumper 41 to the head 15, thence through the switch blade '14 to the switch jaw 13 and the base 4, by way of the flexible jumper 37 to the inner terminal 35 and its brush 34 to the projectile cylinder 29, thence by the flexible jumper 36 to the projectile 25 and through the ignition wire 26 to the block 20, and from thence to the brush 32 carried by the outer terminal 33.

neareas The operation of the device is as follows:

Upon the passage of an excessive current through the circuit breaker the ignition wire, in that fuse which is disposed above the free end of the lever 17, ignites and discharges the explosive which it contains. The projectile 25 is readily forced out of its cylinder 29 to move the free end of the lever 17 downwardly. The end of the lever 17 which is connected to the push rod 16 moves upwardly and pushes the rod ahead of it. The upper end of the push rod it strikes against the anvil 39 and'drives the head 15 upwardly.

The ascent of the head 15 carries the switch blade 14 upwardly to open the circuit at the switch jaw 13. Inasmuch as the break in the circuit occurs in the oil tank 5, the spark is quenched rapidly by the action of the oil.

The head 15 being freely slidable in the guide rods 10, moves upwardly past the pawl 47 until it strikes the top of the casing where its energy oi momentum is expended. As the head 15 starts to move downwardly under the actionof gravity, the pawl 47 enters the opening 42 in the head and engages the loop 43 to temporarily arrest further descent of the head 15. The weight of the head 15 and blade 14 overcomes the tension of the spring 46 to move the lever arm 45 downwardly. The gear train is thus set in motion and the governor 53 is rotated. After a certain degree of rotation the lever 45 becomes sufiiciently inclined to permit the head 15 to be disengaged and descend to its lowermost position to reclose the switch.

When the free end of the operating lever .17 is depressed by the projectile 25, the cartridge block is permitted to rotate under the influence of thespring 22 to bring the next cartridge into position to be engaged by the lever 17. The free end of the lever 17 is raised to its normal position by the spring 17' insufiicient time to engage the next projectile thereby arresting further rotation of the cartridge block. Hence, the circuit breaker is automatically re-fused and thus, when the blade descends and is engaged by the jaws the circuit is reclosed. If the excessive current again passes through the circuit breaker the cycle of operations .is repeated. It will be seen'that as long as the overload remains on the line, the cycle of operations will be repeated, until the cartridges have all been discharged. Where it is expected that long overloads will occur, it will be necessary therefore, to provide enough cartridges, or to make the interval between successive cycles sumciently long, so that the switchopening mechanism will not fail to operate if the switch is reclosed While the overload is still on the line.

Many uses of the invention will suggest themselves to persons skilled in the art. One important use of the invention is its employment in a lightning arrester system of the known type which includes a circuit breaker and a spark gap in a circuit between a power line and ground. When a surge occurs due to the efiect of a lightning discharge, the gap breaks down and permits current to flow to ground. However, if current continues to flow, the fuse is discharged and the circuit breaker is actuated to open the circuit. The circuit breaker is automatically reclosed and if the excess voltage is no longer present, the current will not flow in the ground connection but if the excess voltage is still present the circuit will again operate and will continue to do so until the line is cleared/or until all; of the fuses have been discharged.

I claim: 1. In a.circuit opening device, the combination with a set of cooperating contacts, of means actuated by the passage of an electric current through said device, for separating said contacts, said means comprising a projectile arranged to strike against a member connected to one of said contacts, and means for reestablishing engagement between said contacts.

2. In a circuit opening device, the combination with a set of cooperating contacts, of means for separating said contacts comprising a projectile expelling fuse having its projectile arranged to strike against a member connected to one of said contacts, and means active upon the discharge of said fuse for resetting said separating means. 3. In a high tension circuit breaker, the combination with a stationary contact member and a movable contact member, of means engaging said movable contact member and active upon the passage of an excessive current through said circuit breaker, for moving said movable contact member upwardly away from said stationary contact, guide means for returning said movable contact member to its original position and means for delaying the descent of said movable contact member for a predetermined period of time.

4. The invention as set forth in claim 3, wherein said guide means constitutes a support for said delaying means.

5. The invention as set forth in claim 3, wherein said delaying means comprises a member lying in the path of movement of said movable contact member and engageable thereby.

6. In a high tension circuit breaker, the combination with a stationary contact member and a. movable contact member, of means cooperating with said movable contact member comprising a projectile dischargingcartridge for separating said contacts, a second cartridge and means, actuated by the discharge of said first cartridge, for substituting said second cartridge in the place of said first cartridge in said separating means.

'7. In a high tension circuit breaker, the combination with a set of switch contacts, of a member carrying projectile expelling fuses, operating means for transmitting to one of said contacts the energy of a projectile expelled from one of said fuses to move said contact *away from-its cooperating contact and means actuated by the discharge of said fuse for rotating said member to move another of said fuses into operative relation with said operating means.

8. In a repeating circuit breaker for high tension circuits, a switch comprising a set of cooperating contact members, operating means for opening said switch comprising a projectile expelling explosive fuse actuated by the flow of an excessive current through said. switch, a second fuse, and resetting means, active upon the ex plosion of said first fuse, for substituting said second fuse for said exploded fuse.

9. In a high tension circuit breaker, the combination with a self-recl'osing switch, of means for opening said switch including a plurality of explosive fuses, one of which is arranged in operativeposition with relation to said switch, and

means, active upon the discharge of said operative fuse, for removing said discharged fuse and position.

10. In a high tension circuit breaker, the combination with a set of switch contact members, of operating means including an explosive fuse for separating said contact members, and means operative upon the discharge of said explosive fuse for resetting said operating means.

11. The invention as set forth in claim 10, wherein said movable contact member comprises a blade portion and a head portion and said operating means comprises a push rod arrang to strike against said head portion.

1a. In a high tension circuit breaker, the com-, bination with a stationary contact member and a movable contact member, of means including an explosive cartridge disposed in cooperative relation with said movable contact member for separating said contacts, a second means including a her to its position in engagement with said stationary contact member.

. A JOHN P. MEDLIN.

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