US2900469A - Circuit-breaker control device - Google Patents

Description

Aug. 18, 1959 J. L. GRATZMULLER CIRCUIT-BREAKER CONTROL ,DEVICE 2 Sheets-Sheet 1 Filed Dec. 27, 1954 S.. ...u 1 a 2 4.

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CIRCUIT-BREAKER CONTROL DEVICE 2 Sheets-SheetI 2 Filed Dec. 27. 1954 FIG. 2o

2,900,469 CIRCUIT-BREAKER CONTROL DEVICE Jean Louis Gratzxnuller,l Paris, France Application December 27, 1954, Serial No. 477,670 Claims priority, application France January 1S, 1954 4 Claims. (Cl. Z00-82) In most of the circuit-breakers or other electric switching devices, at least a part of the switching mechanism is at high potential, at least normally i.e. when the circuitbreaker is in contact-making position and fed with current. Now, the control of circuit-breakers is usually eflfected from the ground, or more generally at a remote control station by a control arrangement at ground potential. v

In these conditions, the said control requires:

` (l) That the mechanical connection between such control station and the part of the mechanism which is at ground potential be ensured exclusively through insulating means. o

(2) A power circuit or transmission from the ground to the part of the mechanism at high potential, to actuate the circuit-breaker. I

(3) The possibility of continuously supervising at the o'control station the operation of the circuit breaker.

Moreover, generally speaking, the operation of a circuit-breaker further requires:

" (l) a'rapid and safe contact break,

(2) a safe and sure holding of the movable contact lmember in both contact-making and contact-breaking po- `isitions Finally, it is advantageous to reduce to a minimum the nurriber of connecting elements between the parts at high Apotential and the parts at ground potential.

'Ilhe invention has for its purpose to provide a circuitbreaker control device fulfilling all these requirements while being far more simple and, hence, far cheaper than all the existing control devices.

The circuit-breaker control device according to the invention essentially comprises a part at ground potential, a part directly associated with the mechanism to be controlled, and hence, at the same high potential as the said 'mechanism and an insulating connection between both said parts. vAn object of the invention is to provide a control device' of this type, wherein the part at high potential is constituted by a single acting hydraulic jack adapted to be operated by an insulating liquid such as oil against elastic means capable of returning the jack piston to its yoriginal position, as the liquid contained in said jack is evacuated, wherein the part at ground potential comprises a source capable of feeding the said jack with the said lnsulating liquid at a suitable pressure and means for `controlling feeding of the jack and evacuation of liquid 'therefrom and wherein theconnection between both parts is essentially constituted by a duct made of an insulalting-material as well as by the column of insulating liquid contained in the said duct.

n further object of the invention is therefore to complete the control device by a manometric instrument 'adapted to detect the pressure in the part at ground potential of the feeding duct. As soon as the said pressure is higher than the pressure required for completing the whole active stroke of the jack piston against the action ,of the elastic means or, on the contrary, lower than the 2,900,469 Patented Aug. 18, 1959 lee in one position to establish circuit making relation and in another position to break the circuit, permanently available force applying means operably connected to the movable member to move the same in one direction, a source of liquid under a constantly available predetermined pressure valve-controlled conduit means governing the ow of said liquid and in which the circuit breaker includes a single acting hydraulic jack actuated in one direction only by said liquid and with the movable member of the jack operably connected to the movable circuit making and breaking member, and in which means are provided for rapidly evacuating the jack under valve control substantially in accordance with the teaching of my prior filed U.S. application Serial No. 474,538 filed December l0, 1954, and titled Remotely Controlled Evacuation Device for Hydraulic I ack.

It is a specific object to provide a circuit breaker of the type set forth in the immediatelyv aforegoing paragraph with the afore-referred to insulating conduit means incorporated between the substantially permanently available source of liquid under pressure and the jack and in which the liquid is fed to the jack in a completely insulated path and when the jack is discharged under valve control the fluid being discharged constitutes a portion of the insulation.

Other objects and advantages of the invention will be apparent from the following detailed description, together ywith the accompanying drawings, submitted for purposes of illustration only and not intended to deine the scope of the invention.

In these drawings:

Figure 1 is a diagrammatic view of a suspended circuitbreaker provided with a control device according to the invention including an oleo-pneumatic accumulator which for purposes of clarity is illustrated on a greatly enlarged scale.

Figures 2 and 2a together illustrate a modification showing a single insulating connection ensuring both feeding of the jack and return of liquid to the container, the respective figures are partly in elevation and partly in longitudinal section, with Figure 2 illustrating the bottom half of the arrangement and Figure 2a the top half.

The suspended circuit-breaker diagrammatically shown in Figure l comprises a body 1 made of an insulating material such as porcelain and terminated at both ends by two tightly closing members 2, the said body containing the circuit-breaking chamber 3. The body 1 is suspended, for example on a suitable bracket4, through insulators 5, the length of which is calculated as a function of the voltage of the current to be cut-off.

One of the conductor lengths to be separated, 6, is connected to a fixed contact 7, e.g. tulip-shaped, engageable by a movable contact 8 slidably mounted in a sleeve 9 to which is connected the other one 10, of the conductor lengths to be separated.

The conducting rod constituting the movable contact 8 is solid with the piston 50 of a hydraulic jack 51 having for its function to bring the movable Contact 8 into contact-making engagement with the fixed contact 7, against the action of elastic means, such as the springs 11, capable of ensuring circuit-breaking by returning the rod 8 into such a position and at such a speed as to safely ensure contact-breaking. With this arrangement, the part of the mechanism comprising the jack 51, its piston 50, its springs 11, and the movable contact 8 is always at the same voltage as the conductor length 10. The inner insulation ofthe circuit-breaker between the poles 7 and 9, when the contacts are separated, is ensured in the usual manner e.g. by oil contained in the circuit-breaking chamber 3.

According to the invention, the jack 51 fed from a source of insulating liquid such as oil, under pressure, the said source being constituted, in the example shown by an oleo-pneumatic accumulator 12, through an insulating duct 13 which is preferably flexible at least along a portion of its length, the said duct being further provided with usual outer insulating means such as a porcelain insulator 14. As described in my prior Patents No. 2,724,412 dated November 22, 1955, and entitled Hydropneumatic Accumulator, and No. 2,746,486 dated May 22, 1956, and entitled, Fluid Tight Assembly, the oleopneumatic accumulator 12 includes a casing 120 having a movable partition or piston member 121 dividing the interior of the casing into a liquid containing compartment 122 and a compressed gas containing compartment 123. The accumulator is charged with liquid and pressurized gas to such an extent that the partition or piston exerts a force on the liquid in the liquid compartment sufficient to place that liquid under a constantly available pressure that is far in excess of the force of spring forceapplying means 11.

The feeding of the jack 51 is controlled in the diagram- -matic scheme of Figure 1 by a simple three-way cock -15 actuated e.g. by a contact-making electro-magnet 16 and a contact-breaking electro-magnet 17 (see Figure 2). In the position shown in Figure l of the three-way cock 15, it may be seen that a pressure fluid is sent into and :maintained in a jack 51, so that the movable contact 8 of the circuit-breaker 1 is held in the contact-making position shown, in which the two conductor lengths 6 'and 10 are interconnected. An abutment 52 locates the piston 50 and, hence, the movable contact 8 in a correct :position ensuring a good electric contact.

The contact-breaking electro-magnet 17, when energised, causes evacuation of the liquid from the jack -51through the insulating duct 13 e.g. by setting the same finto communication with the liquid container 18 upon a vsuitable actuation of the three-way cock 15. It is to be understood that the above description is given as a mere illustration while, in practice, the control of the feeding 4and unloading of the jack may be made in any suitable 4manner within the scope of the invention.

I have diagrammatically shown at 19, under the form of a simple manometer, a'device responsive to the pressure in the duct 13 and consequently in the jack 51.

Such a pressure-responsive device permits, according to another feature of the invention and as already mentioned above, knowing at any time the position of the circuitbreaker.

In practice, such a device will be preferably provided with displaying means such as signal lamps, so as to permit directly supervising the operation of the circuitbreaker (see Figure 2).

There is shown at 20 a chain for anchoring the suspended circuit-breaker, the said chain being secured at the lower end of the insulator 14 of the duct 13.

In the embodiment of the invention shown in Figures 2 and 2a the component parts that are the same as in the vFigure 1 arrangement bear thc same reference characters.

Thus, in this form of the invention there is disclosed a circuit-interrupting device which, like in the Figure l arrangement, is a suspended device, and incorporates a `porcelain body 1 closed at each end by closure members 2 so that the interior of the body denes a circuit-breaking chamber 3. The body 1 is suspended by suitable .insulators 5. Within the body is a stationary contact 7, `a. movable contact 8 that is slidably mounted in a sleeve .v9 and which is fast with the rod ofV piston 50. The respective conductors are denoted at 6 and 10 and these are, respectively, in circuit with the fixed contact 7 and the sleeve 9. Spring force applying means 11 are operatively associated with the movable contact 8 in that they surround rod members 111 carried by a bracket fast with the rod of piston 50. These rods 111 are disposed through holes in a casing 112 and the spring force applying means 11 are biassed between the bottom of the casing and heads on the ends of rods 111. Thus the spring force applying means constantly urge the movable contact toward circuit-breaking position. Depending beneath the casing 112 is a hydraulic jack 51 constituting cylinder and piston means, one of which is movable relative to the other. In this case the piston 50 is movable relative to the cylinder of the jack 51. As stated previously, the movable contact 8, being fast With the rod of piston 50, is thus permanently and kinematically connected to the movable one of the cylinder and piston means so that for every position of the piston 50 there corresponds a precise position of the movable Contact. An oleo-pneumatic accumulator 12, similar to the Figure 1 arrangement, is provided to furnish liquid under pressure for actuating the movable contact to circuit-making position. The system further includes a tank 18 and conduit means including a first portion 13a in communication with the liquid compartment of the accumulator and leading to manually actuated control valve means 15', a second portion 13b that is flexible and communicates with a further conduit portion 13C surrounded by an annular insulation member 14 that provides an annular space or duct 24 about conduit portion 13e. The conduit portion 13C is extended to enter a container or canister 22 within which is disposed means for rapidly discharging liquid from the jack in response to suitable actuation of the control valve means 15. Thus, as described in my prior tiled application Serial No. 474,538, filed December V10, 1954, and entitled Remotely Controlled Evacuation Device for Hydraulic I ack, the liquid from the liquid compartment of the accumulator ows through the conduit means with the control Valve in the position shown in Figure 2 and enters a Valve casing 220, Figure 2a.

Within the casing is a movable piston type valve member 221 having a central bore 222 within which yis a nonreturn ball valve 223. A passage 224 provides communication between the central bore 222 and a further passage 225 leading to the lower end of the cylinder of the jack 51. The end of the partition or piston 221 remote from the outlet end of conduit portion 13C is shaped to dene a valve member that cooperates with a seat on a discharge duct 226. Therefore, when liuid under pressure enters casing 220, it unseats the ball valve 223, applies the valve head 227 to close discharge duct 226, flows through duct 225 into the jack to raise the piston 50 and thus move the movable contact 8 to circuit-making position. Since the uid is locked in the cylinder the means for maintaining the circuit constitutes the pressure of the liquid within the cylinder. From the lower end of the tank or canister 22 there extends a conduit portion 25, see Figure 2, that is in communication with the annular space or conduit 24 between the insulator 14 and conduit portion 13C. From the lower end of this annular space there extends another conduit or pipe portion 26 that communicates with a valve chamber 30. From the valve chamber 30 there extends a return duct 27 that communicates with the tank 1S.

The system, see Figure 2, further includes a return pipe 270 providing return flow communication between the control valve means 15 and tank 18. Closure and packing means 28 and 29 are provided at opposite ends of insulation member 14 to insure the fluid tightness of the annular passage or duct portion 24.

The manually actuated control valve means includes a contact making electromagnet 16 and a contact breaking electromagnet 17 operably coupled with the lever 15"' of the control valve 15. A suitable manually actuated l by..

switch 17,0V effects energization `of the electromagnets 16 and 17 in a desired manner so that in the position shown in the drawing contact making electromagnet 16 has drawn the lever 15 to a position to move the valve means toy establish communication between the liquid compartment of the accumulator and the cylinder of the jack so as to elfect movement of the movable contact into circuit-making position. Since the dumping valve means within the tank 22 is also a part of the conduit means, the contact is permanently maintained in circuit-making position solely by the pressure of the liquid in the cylinder. When the valve means 15 are actuated in another position as aresult of movement of switch 170, communication is established between the cylinder and the tank via the dumping valve and also by the reverse ow through conduit portions 13C, 13b and 270. When the pressure beneath movable partition or piston 221 in the dumping valve mechanism is lowered by the reverse ow through conduit 270 -to tank 18, the spring force applying means 11 drives the piston S1 downwards in its cylinder so that lthe movable member or partition 221 moves down to open discharge duct 226. As disclosed in said prior iiled application Serial No. 474,538, the cross-sectional area of the discharge duct 226 is larger than lthat of the inow duct 225 so that liquid rapidly ows into tank 22 and thence out into the conduit portion 25 through the annular duct 24 past the valve 33 and into the tank 18. It

4is therefore clear that the invention provides liquid dumping means operatively associated with and adjacent the cylinder of the jack and in communication with the tank and operable when the valve means 15 is in the position determined by electromagnet 17 to rapidly evacuate liquid from the cylinder and to discharge liquid vto the tank.

It is further to be noted that in the hydraulic jack 51 the inow conduit means 13a, 13b, 13e, and a substantial portion of the outflow conduit means including the annular duct 24, are disposed in more or less in line relation, with the annular duct 24 being coaxial with and surrounding a substantial portion of the length of the conduit means 13C.

It has been explained hereinabove that the insulating connection between the part of the mechanism at high potential and the control station at ground potential is ensured by the column of pressure liquid contained in the duct 13 as well as the said duct itself and its outer insulation. For the return pipe, it is preferred, for ensuring the presence in the annular passage 24 of an insulating liquid column of a level corresponding at least to the insulating length required by the voltage of the current to be cut olf, to interpose e.g. between the pipe length 26 and the return duct 27 a valve provided with a diaphragm 34 acted upon by a return spring 31. Said valve has one chamber 30 communicating with atmosphere at 32, while its other chamber communicates, on the one hand, freely with the pipe length 26 and, hence, with the annular passage 24 and, on the other hand, under `the control of a valve closing member 33 solid with a diaphragm 34, with the duct 27 leading to the container 18.

In these conditions, it will be understood that, as soon as the pressure in the pipe length 26 becomes lower than a predetermined value corresponding to a certain level of the lluid in the annular passage 24, the diaphragm 34 yields under the action of the spring 31 and seats the closing member 33 of the valve thus interrupting tlow of liquid towards the container.

In the showing in Figure 2, the above mentioned means responsive to the pressure in the duct 13 and provided 4to give an indication of the circuit breaker position, include a jack 35, the piston 36 of which is subjected on one side to the action of a calibrated spring 37 and on the other side to the pressure in the duct 13. The rod 38 of the piston 36 carries a contact 39 switchable between two pairs of fixed contacts 40, 41 respectively incorporated in the feeding circuits of two signal lamps 42-43 fed with electric current from any suitable source such as the battery 44. This device is so adjusted that the movable contact 39 completes the circuit of the lamp 42 when the pressure inthe duct 13 is higher than the value required for ensuring the complete contact-making stroke of the jack piston 50, while it establishes the circuit of the lamp 43 when the said pressure is lower than the value for which the springs 11 are capable of ensuring the whole circuit-breaking stroke of the said jack piston.

While the invention has been described with particular reference to a preferred embodiment, it is not intended to limit the scope of the invention to the embodiment illustrated, nor otherwise than the terms of the subjoined claims. Y

In particular, the invention may be applied to circuitmakers and more generally to any switching device, 4iii particular for high-voltage current.

What is claimed is:

l. A circuit-interrupting device including a stationary contact, a movable contact, spring force applying means operably connected to said movable contact to constantly urge the same toward circuit-breaking position, cylinder and piston means one of which is movable relative to the other, means permanently and kinematically connecting the movable one of said cylinder and piston means to said movable contact so that for every position of said movable one of said means corresponds a precise position of said movable contact, an oleo-pneumatic accumulator including a casing, a movable partition within the casing and dividing the interior thereof into a liquid containing compartment and a compressed gas containing compartment, liquid in the liquid containing compartment under a constantly available pressure far in excess of the force of said spring force-applying means, a tank, conduit means between the liquid compartment of the accumulator and the cylinder, and between said cylinder and said tank, manually actuated valve means operably associated in said conduit means and operable in one position to establish communication between said cylinder and liquid compartment and block communication between said cylinder and tank so as to effect movement of said movable contact into circuit making position and to permanently maintain said circuit solely by the pressure of liquid in the cylinder, said valve means being operable in another position to establish communication between said cylinder and tank and block communication between said compartment and said cylinder, whereby said spring force applying means can effect movement of said movable contact to circuit-breaking position, and liquid dumping means operably associated with and adjacent said cylinder and in communication with said tank and operable when said valve means is in said another position to effect rapid evacuation of liquid from said cylinder and to discharge liquid to said tank.

2. A circuit-interrupting device as claimed in claim 1, and further including liquid pressure responsive signaling means operably associated with the conduit means between said manually actuated valve means and the cylinder for indicating the position of said movable contact, said pressure responsive signal means including a conduit in communication with said conduit means between said eylinder and said manually actuated valve means.

3. In a circuit-interrupting device as claimed in claim l, and said conduit means between the liquid compartment of the accumulator and the cylinder including a portion disposed in substantial alignment with said cylinder, an insulator surrounding a substantial part of said portion of said conduit means and in spaced relation thereto, the conduit means providing communication between the cylinder and the tank including the space between the insulator and the said portion of the first-mentioned conduit means.

4. In a circuit-interrupting device as claimed in claim 1, and the conduit means between the cylinder and the tank 7 including anv annular duct surrounding a portion of the conduit means that extends between the liquid compartment of the accumulator and the cylinder, a conduit portion providing communication between the liquid dumping means and one end of the annular duct, further conduit means providing communication between the other end of the annular duct and said tank, and valve means operably associated with said further conduit means and operable to maintain an insulating liquid column within said annular duct, said Valve means being operable in response to pressure of liquid within the additional conduit means between said other end of the annular duct and said valve means to control the level of the liquid in the insulating column in response to pressure of liquid so as to block communication between said valve means and the tank whenever the liquid level within the insulating column falls below a predetermined level.

References Cited in the le of this patent UNITED STATES PATENTS Weissberg May 15, 1917 Hoopes Mar. 17, 1925 Niutta Nov. 3, 1931 Gray Sept. 18, 1934 Willheim Apr. 27, 1937 Dufng Feb. 11, 1941 Dung Apr. 22, 1941 Loos June 24, 1941 Beh-ringer Nov. 4, 1941 Duing July 21, 1942 Bartlett et al Ian. 12, 1943 Lerstrup Nov. 4, 1947 Kelle Mar. 15, 1949 Peek Dec. 11, 1951 Perry et al. Oct. 2, 1956

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