US2830145A - Isolator switch - Google Patents

Description

AprilB, 1958 s. c. KILLIAN ISOLATOR SWITCH 2 Sheets-Sheet 2 ba m 1% Filed Feb. 11, 195

- mmvron.

. BY 3m I United States. Pate t 7 2,830,145 ISOLATOR SWITCH Stanley C. Killian, Glen Ellyn, llL, assignor to H. K.

Porter Company (Delaware), a corporation of Delaware Application February 11, 1955, Serial No. 487,489 7 Claims. 01. 200-48) The present invention relates to switch means, and particularly, to an improved switch for isolating electrical equipment from a high tension power supply.

In substations and like installations, where'connections are brought up through a switch to a high capacity aerial conductor or bus, it is customary to mount the switch on a platform or tower in elevated relation between the ground and the conductor. The switches employed perform the function of selectively connecting electrical equipment to and disconnecting or isolating the quipment from the power supply. A type of switch conventionally employed in such installations is the vertical'air break switch, such as disclosed in Patent No. 2,231,992 to T. Fjellstedt, issued February 13, 194-1, and in Patent No. 2,527,924 to T. Fjellstedt and me, issued October 31, 1950, both of which patents have been assigned to the Fee 2 mounted directly on the high capacity conductor or .bus, thus eliminating the stack of insulators usually required for" supporting the stationary contact and the elongate base required in known disconnect switches.

An additional object of the invention is to provide an improved switch in accordance with the foregoing where in the stationary contact is mounted on the conductor or bus vertically above the switch blade mounting, the short switch base is mounted horizontally, the two closely adjacent insulator stacks project verticallyfrom the base, and the switch blade is movable to a vertical closed position and'a horizontal open position, thus to accommodate installation of the switch in a minimum area and in an optimum manner.

A still further object of the invention is the provision of an improved isolating switch of sturdy construction,

, assuring a long useful life and optimum performance,

assignee of the present invention. As shown in the two patents, switches of the general character comprise an elongate rigid base, three insulator stacksprojecting perpendicularly from the base in spaced parallel relation,

. two of the insulator stacks being disposed closely adwhich isrotatable-or movable, for swinging the switch blade in an arc to and away from the stationary contact, respectively to close and open thecircuit. Normally, switches of the character defined are mounted hori- 'zontally in'a substation, i. e., with the switch base horizontal and the insulators vertical. 9 To so mount known switches, a supporting structure of a length and width at least equal'tothe length andwidth of theswitchbase'; and the requisite real estate on which to erect the structure, are necessary. As will be obvious to those acquainted in the art, the expenses involved in acquiring the necessaryrealty anderecting the supporting structure, as to cost of both material anderection, are very substantial inswitches of the capacity generally referred to. Further, in existing; substations, space requirements for switches may pose very substantial, and in some cases insurmountable, problems. i I

It is an object of the present invention to provide an and at the same time affording the user substantial economies in terms of cost, installation and space.

Other objects and advantages of the present invention will become apparent in the following detailed dCSCIlP', tion of a preferred embodiment of the invention.

Now, in order to acquaint those skilled in the art with the manner of making and using'the improved switch of the present invention, 1 shall describe, in connection with the accompanying drawings, a preferred embodiment of the invention and a preferred manner of making the same.

In the drawings: Figure 1 is a plan view schematically showing a substation bus, switch and circuit-breaker arrangement in corporating the switch of the invention;-

Figure 2 is an end elevation of the apparatus shown in Figure I; i V Figure 3 is a side view, partly in section and partly in elevation, of the improved switch of the invention; and a Figure 4 is an end elevation of the switch. "i i Referring to the drawings, and particularly to Figures 1 and 2, l have schematically represented a substation switching arrangement including conventional aerial conductors ill, 11 and 12 which are each supported by strain insulator means 13 on the horizontalgirders 1'4 'of'spaced tower structures 15 (a portion of one such structure being shown in the drawings). Switch means are associated with each of the conductors, the switch means comprising an isolating switch 20, 21, 22 associated with the respective conductor 10, 11, .12, and an interrupter or circuit breaker, such as the oil circuit breakers 3d, 31, 32 shown, associated with the respective switch 20, 21, 22. 'The isolating switches 20, 21, 22 are shown as mounted on individual supporting structures 25, comprising metal fabricated towers, which elevate the switches with respect to the ground, as is conventional. The isolator switchesjm, 21 and 22 constitute the particular'improvement afiorded according to the present invention and these switches accommodate and afford very substantial savings in material, construction and space.

The isolator switch" of the present invention is shown I in greater detail. in Figures'3 and 4 as comprising a base electric power transmission system.

40, a pair of insulator stacks 42 and '44 projecting perpendicularly from the base, a switchblade dfi mounted on the insulator stacks for movement with respect thereto,

and a stationary contact 48. An important feature of the a rigid bus bar, the stationary contact 'may' be clamped 'improved'switch including a: stationary contact, to be or otherwise secured rigidly to the bus where desired; If the-conductor is a cable or group of cables, I prefer to mount the stationary contact adjacent a tower structure,

so as to obtain a high'degree of stability and rigidity.

However, mounting of the contact immediately adjacent a tower structure or strain insulator is not always possible. If the conductor comprises a group of cables, substantial rigidity is afforded even if the contact be mounted a substantial distance from a supporting structure." In the drawings, 1 have shown a preferred form of contact for mounting on a cable and as is to be appreciated from Figure 1, each contact is mounted as close as possible to a strain insulator 13. The contact structure, as shown in Figure 3 comprises a pair of T-connectors 50 which are clamped to the cable 10, both for mechanical support and in electrically conductive relation, in longitudinally spaced relation on the cable. At their'lower ends, the T-connectors support the opposite ends of a base plate or rod 52 which is preferably disposed parallel to the conductor. The rod 52, at substantially the midpoint thereof, carries the contact structure which, as shown, comprises a clamping portion 54, a vertically depending leg 56 and a plurality of spring contact fingers 58 secured to opposite sides of the leg 56 and extending therefrom longitudinally of the cable to define a generally U-shaped contact. The rod 52 also carries a pair of transverse supports 60 which in turn carry control rings 62 of a generally conventional nature at opposite sides of the U-shaped contact. The various parts of the contact assembly described as formed of suitable metals well known in the art so that the contact fingers 58 are maintained in electrically conductive relation to the cable. The contact fingers themselves are preferably formed of resilient material so as to effect high pressure engagement with the switch blade 46, and the outer ends of at least one. pair of fingers are preferably flared outwardly to a substantial extent to facilitate entry of the switch blade 46.

contacts 84 in the closed position of the blade to close the circuit between the terminal pad 80 and the conductor 10. Preferably, the inner end portion of the blade is provided with diametrically opposed, longitudinally extending protuberances 86 disposed in longitudinal alignment with the edges of the flattened outer end portion of the blade to effect high pressure, small area engagement with the contacts 84 in the closed position of the switch. 7

Because of its mounting, the switch blade 46 is adapted for a composite movement consisting of arcuate movement about the pivot 70 and rotary movement about its own axis. To effect this composite movement, the switch includes a drive mechanism comprising an angle pin 88 fixed to or formed integrally with the blade carriage 66 and an operating crank 90 having a tubular bearing por tion 92 complementary to the pin 88. The crank 90 is fixed to one end of a rotatable operating shaft 94 so that the crank is mounted for rotation aboutan axis intersecting and disposed at right angles to the pivot axis 70. In preferred embodiments of the operating mechanism, the

' axis of the switch blade 46, the pivot axis 70 of the blade,

The switch blade and operating mechanism shown in l carriage is journalled in .ajblade guide 68 to mount the blade for rotation. about its own axis. The blade guide 68 is pivotally mounted at 70. on the upstanding spacedparallel legs 72 of .a stationary frame 74, the blade guide and carriage thus also mounting. the blade for arcuate movement about a horizontal pivot axis at 70. The frame 74 in turn is stationarily mounted on the upper end of the insulator stacks 42 and 44.. The stack 42 is preferably disposed in axial alignment with the blade when the blade is in' itsclosed position as shown in Figure 3. The frame 74 is stationarily secured to the stack 42 and the stack is stationarily supported on the base '40. The

' other insulator stack 44 is rotatably supported on the base 40, in closely adjacent, spaced parallel relation to the stack 42, andat its upper endis journalled for rotation in the frame 74. The base 40 preferably comprises a pair ofspaced parallel I-beanis 76 and the insulator stack 44 preferably includes an operatingshaft extending downwardly between the two beams to terminate in an actuating head 78 located beneath the lower surfaceof the beams. I

In addition to pivotally supporting the-switch blade, the frame 74 comprises terminal means for the switch, the frame being formed of metal and defining a terminal pad at 80. Within the interior thereof, the frame may be provided'with bosses 82 for mounting U-shaped spring contacts 84. As shown in Figure 3, the switch blade 46 includes'a free inner end portion which engages in the the axis of rotation of the crank 90, and the axis of the pin 88 intersect at a common point, and the pin 88 is disposed at substantially a 45 angle to the crank axis and the blade axis. Variations may of course be made in this arrangement. In any case, the resultant effect is that upon rotation of the crank, the previously referred to composite movement of the blade takes place, the blade being simultaneously swung in an arc about the pivot axis 70 and rotated about its own axis, approximately 90 of crank rotation resulting in approximately 90 arcuate swinging and approximately 90 rotation of the blade.

While I prefer to employ the blade supporting and operating structure shown, other known operating structures for air break switches may be employed with substantially equal facility.

According to the present invention, the switch blade supporting and operating structure departs from conventional practice in being disposed upright rather than horizontal on the frame and in being actuated by a horizontal shaft 94 rather than a vertical shaft. Disposition of other known switch mechanism in this manner will be apparent to those skilled in the art in the light of Figures 3 and 4 of the drawings.

Further according to the invention, the horizontal actuating shaft 94 is rotated by means of the rotatable insulator stack '44 through a transmission assembly 96 mounted on the frame 74, the assembly including meshed bevel gears 98 for transmitting rotary movement from the stack 44 to the shaft 94 and bearing means rotatably supporting the shaft 94 and the upper end portion of the stack44.

In installation, the stationary contact 48 of the switch of the invention is secured, as described, at a suitable I location on an aerial conductor 10. The short base 40 of the switch is mounted on a supporting structure 25 vertically beneath the contact 48, i. e., with the stack 42 and the switch blade 46 in vertical alignment with the center of the U-shaped contact defined by the contact fingers 58. Because of the shortness ofthe base, the size of the supporting structure is very small compared to conventional structuresand the area and amount of real estate required for erection of the structure and the switch are vastly reduced. For a three phase power transmission system, threeisolator switches are provided, one for each phase. The three switches may be aligned transversely of the transmission lines, or may be disposed in staggered relation, such as shown in the schematic representation of Figure 1, or in such relation as may be desired... Asis conventional, the actuating shafts 78 of the, switches may be interconnected to facilitate simultaneous actuation of the three Switches.

The blade of each switch is movable to a substantially 5 vertical close d position from a substantially horizontal open position. In the open position, the blade extends horizontally outward from the top of the insulator stacks, as is shown in dotted lines in Figure 3, and in this position, the blade is turned to dispose the flattened end 64 thereof vertically as is shown. Upon rotation of the rotatable insulator stack 44, the operating mechanism raises the blade, arcuately swinging the same about the horizontal pivot axis 70. To assist in this movement, particularly in the high capacity switches, counterbalancing springs or like counterbalancing means, not shown, are preferably provided, as is known in the art.

Simultaneously with the swinging of the blade, the blade is rotated about its axis, these two movements being correlated so that as the beaver-tail portion 64 of the blade enters the contact 48, the beaver-tail is disposed at an oblique angle to the contact fingers 58. During continued rotation of the stack 44, the blade is moved arcuately to a predetermined position within the contact and is simultaneously rotated about its own axis so as to position the beaver-tail 64 at substantially right angles to the contact fingers, rotation of the blade in this latter movement being greater in relation to the arcuate swing of the blade. The contact fingers are normally spaced apart by a distance less than the width of the beavertail end portion ofthe blade, but because of the oblique disposition of the beaver-tail in the initial stages of entry between the fingers, the blade freely enters the contact. Thereafter, the majority of the input force is utilized to rotate the blade so that the beaver-tail or flattened end portion of the blade is readily twisted into ,camming engagement with the contact fingers to wipe the engaging portions of the blade and fingers and to effect high pressure, small area contact between the same, thus insur ing optimum electrical coupling of the blade and contact. At the same time, substantially the same action occurs with respect to the inner end portion of the blade as between the protuberances 86 and the contacts 84, the blade thus establishing electrical connection between the conductor 19, 11 or 12 and the terminal pad 80.

Upon opening of the switch, substantially the reverse movement occurs. Initially, the switch blade is rotated to a substantial extent in relation to arcuate movement to free the high pressure engagement of the blade and its contacts, and subsequently arcuate movement predominates to return the blade to its open position. Due to the nature of the opening and closing movements of the blade, the load imposed upon the stationary contact 48 and the conductor 10, 11 or 12 is slight, and the load is exerted longitudinally of the conductor so that the strain is readily supported. The entry of the flattened end portion of the blade into the contact at an inclination also serves to assist in aligning the contact with the blade to insure optimum switching performance.

As is to be appreciated from the foregoing, the present invention provides an improved switch structure affording, in contrast to conventional switches, very substantial savings in terms of material, assembly time, cost of construction and erection, real estate, and space generally. For example, a 330 kv., 1600 ampere isolator switch of conventional design would employ a 5" diameter blade approximately 13 /2 feet long, three insulator stacks each approximately 9 feet tall and over a foot in diameter, and a mounting base approximately 1 foot high, 1 /2 feet wide and approximately 18 to 20 feet long. In the same capacity, the switch of the present invention eliminates one of the three insulator stacks and the large terminal casting normally required for the stationary contact, and accommodates shortening of the base by 13 or more feet to approximately 5 /2 feet. These economies, of course, are very substantial. In addition, shortening of the base in the particular capacity reduces the required length of the supporting structure 25 by more than 13 feet and saves a horizontal area of at least 20 square feet. Actually, the savings in real estate are even more substansome;

6 tial, since the supporting structure 25 would normally be trapezoidal. Accordingly,it is seen that the present invention reduces'in'sulator cost by one third, the, cost of the base by approximately and the cost; of the supporting structure by more than 75%. Since,. in any three phase system, three switches are required, the total savings and economy effected in a single installation are very substantial indeed. Also, the present, invention accommodates vast reductions in the real estate-required,

in the time required for assembly of the switch, and in the time required. for and the costs of switch erection.

' 'While I have described what I regard to be a preferred embodiment of my'inventio'n, it will be apparent to those skilled in the art that various changes, rearrangements and modifications may be made therein without departing from the scope of'the invention, as defined by thejapp'ended claims. I

'I-c'laim: a

1. An isolator switch for isolating electrical equipment from a high capacity conductor, comprising a stationary contact to be mounted directly on the conductor, an arcuately movable switch blade movable into and out of engagement with said contact, a frame pivotally supporting said blade, a stationary insulator stack supporting said frame, a moveable insulator stack disposed closely adjacent said stationary stack and operatively connected to said blade for'moving said blade, and a short rigid base supporting said insulator stacks, said base, stack and frame being supported independently of the conductor and being disassociat'ed from said contact when said blade is moved out of engagement with said contact.

. l 2. An isolator switch for isolating electrical equipment from a high capacity conductor, comprising a stationary contact to be mounted directly on the conductor, a short rigid base to be mounted in spaced parallel relation to the conductor in alignment with said contact, a pair of closely adjacent insulator stacks projecting perpendicularly from said base toward said contact, one of said insulator stacks being rotatable, a frame supported'on at least one of said insulator stacks, a switch blade pivotally mounted on said frame for arcuate movement from a closed position in engagement with said contact, wherein said blade extends longitudinally from said stacks to saidcontact, to an open position transversely of said stacks, and operating mechanism connecting said rotatable insulator stack and said switch blade for imparting arcuate movement to said blade upon rotation of said rotatable stack, said: base,stacks, frame and mechanism being mounted independently of the conductor and being dis associated from said contact in the open position of said blade.

3. An isolator switch for isolating electrical equipment from a high capacity aerial conductor, comprising a stationary contact to be mounted directly on the conductor, a short rigid base to be mounted independently of and beneath the conductor in vertical alignment with said contact, a pair of closely adjacent parallel insulator stacks projecting vertically from said base toward said contact, one of said insulator stacks being rotatable, aframe supported on said insulator stacks, a blade assembly including a hinge section pivotally mounted on said frame tion to a vertical position within said contact and to rotate said blade into high pressure engagement in said contact, said base, stacks, frame and mechanism being mounted independently of the conductor and being disassociated from said contact in the open position of said blade.

4. An isolator switch for isolating electrical equipment from a high capacity conductor, comprising a short rigid base to be'rnounted independently of and in spaced, parallel relation to the conductor, a pair of closely adjacent parallel insulator stacks extending substantially perpendicularly from said base toward the conductor, one of said stacks being journalled in said base for rotation about its own axis, a frame supportedon the other of said stacks, a switch blade pivotally mounted on said frame for areaate movement from a position "wherein the same extends transversely of ,said stacks to a position wherein the same extendssubstantially longitudinally from said stacks toward the conductor, operating mechanism. including a rotatable shaft extending transversely of said stacks and operatively connecting saidrotatable stack and said blade for moving said bladeupon rotation of said rotatable stack, and a stationary icontactto be mounted independ: ently of and in spaced relation to said base, stacks and frame on the conductor in alignment with said blade in the said longitudinal position thereof.

5. An isolator switch for isolating electrical equipment from a high capacity conductor,.comprising a short rigid base to be mounted in spaced parallel relation to the conductor, a pair of closely adjacent parallel insulator stacks extending substantially perpendicularly from said base toward the conductor, one of said stacks being journalled in said base for rotation aboutits own axis, a frame supported on theouter end of the other of said stacks and providing a bearing for the outer end of said one stack, a shaft journalled in said frame transversely of said stacks, motion transmitting means between said one stack'and said shaft for rotating said shaft upon rotation of said'one stack, a blade assembly mounted on said frame, said blade assembly including a hinge member pivotally mounted on said'frame, a blade having a portion journalled in said, hinge sectionand an operating arm extending between and operatively connecting said blade and said shaft, said shaft upon rotation of said one stackrotating said arm to rotate said blade within, said hinge section and to pivotally move said blade and hinge section with respect to said, frame and said stacks through an arcuate path from a position wherein said blade extends transversely of said stacks to a position wherein said blade extends longitudinally from said stacks toward theconductor, and a stationary contact mounted independently of said base, stacks and frame directly on the conductor in alignment with said blade in the last-named position thereof, said blade being moved arcuately into said contact and being rotated therein to efiect high pressure contact engagement between saidblade and said contact. 7 7

6. In an electric'power installation, a conductor, a switch contact mounted directly on said conductor, and a switch mounted in substantially vertical alignment with said contact independently of said conductor, said switch comprising a short substantially horizontal base, a pair of closely adjacent insulator stacks projecting substantially vertically from said base toward said contact and a switch blade mounted on said stacks for arcuate movement to a substantially vertical closed position, said base, stacks and blade being disassociated from said contact and the conductor in the open position of the blade, said blade being of a length to extend substantially vertically between said insulators and said contact to enter said contact and close the switch circuit. 7. In an electric power installation, an aerial conductor, tower structures supporting said conductor at spaced points, a switch contact mounted directly on said conductor adjacent one of said tower structures, said contact including spaced jaws and flare portions extending therefrom, a switch mounted vertically beneath said contact independently of said conductor, said switch comprising a short horizontal base, a pair of closely adjacent insulator stacks projecting vertically from said' base toward said contact and a switch blade pivotally mounted on said stacks for arcuate movement in a V vertical plane from a generally horizontal open position to References Cited in the file of this patent UNITED STATES PATENTS Graves et al Dec. 16, 1924 2,527,924 Fjellstedt ct al Oct. 31, 1950 2,697,144 Owens Dec. 14, 1954 2,748,211 Butz May 29, 1956 2,766,341

Haller Oct. 4, 1956

Images