US3194928A - Center break high voltage switch with circuit interrupters - Google Patents

Description

July 13, 1965 J, J. MIKOS 3,194,928

CENTER BREAK HIGH VOLTAGE SWITCH WITH CIRCUIT INTERRUPTERS Filed July 26, 1962 6 Sheets-Sheet 1' July 13, 1965 J. J. MIKOS 3,194,928

CENTER BREAK HIGH VOLTAGE SWITCH WITH CIRCUIT INTERRUPTERS Filed July 26, 1962 6 Sheets-Sheet 2 July 13, 1965 J. J. MIKOS 3,194,928

CENTER BREAK HIGH VOLTAGE SWITCH WITH CIRCUIT INTERRUPTERS Filed July 26, 1962 6 Sheets-Sheet 5 July 13, 1965 J. J. MIKOS 3,194,928

CENTER BREAK HIGH VOLTAGE SWITCH WITH CIRCUIT INTERRUPTERS Filed July 26, 1962 6 Sheets-Sheet 4 .W/ ,f WWW A mfiii 67 25} k R. @57 8 60 (39 67 I July 13, 1965 J. J. MIKOS 3,194,928

' CENTER BREAK HIGH VOLTAGE SWITCH WITH CIRCUIT INTERRUPTERS Filed July 26, 1962 e Sheets-Sheet 5 J. J. MIKOS July 13, 1965 CENTER BREAK HIGH VOLTAGE SWITCH WITH CIRCUIT INTERRUPTERS 6 Sheets-Sheet 6 Filed July 26, 1962 5 u Q I m\\ mkwwbb m9 g t QSQ i United States Patent 3,194fi28 CENTER BREAK HIGH VULTAGE SWITCH Wiiitl CIRCUIT INTERRUPTERS' John J. Milros, Highland Paris, lll., assignor to S dz (1 Electric Company, Chicago, 1th, a corporation of Delaware Filed July 26, 1962, Ser. No. 212,613

g Claims. (crass-14s) This invention relates, generally, to electric switches and it has particular relation to such devices for use in electric power circuits operating at voltages of the order of 230 kv. although it is not limited to this particular voltage. It constitutes an improvement over the switch constructions shown in U.S. Patent No. 3,030,481, issued April 17, 1962, to W. A. Gussow and John I. Milros, and shown in application Serial No. 111,998, filed May 23, 1961, by John Mikes and Leonard V. Chabala, now Patent No. 3,163,736.

Among the objects of this invention are: To provide in a new and improved manner for opening an electric power circuit operating at a voltage of the order of 230 kv. and carrying load current; to accomplish this within a minimum of space considering the basic insulation level (BIL) that is required to be maintained is of the order of 900 kv. to 1,300 kv.; to employ disconnect switch blades that have relatively low moment of inertia to facilitate their movement to open circuit position for introducing an air gap in the circuit and from open to closed circuit position; to resist in a simple and eificicnt manner the shock incident to the impact of the rotating parts at the ends of their movements in the switch open and switch closed positions; to employ a pair of pivot-ally mounted disconnecting switch blades arranged to engage and disengage at their distal ends in series with circuit interrupter means and to sequentially operate the construction to the end that the circuit is open by the interrupter means followed by separation of the distal ends of the switch blades to provide the desired air gap and the circuit is closed by closing the interrupter means and then engaging the distal ends of the switch blades to complete the circuit; to provide for maintaining a circuit through the switch blades during the initial portion of their opening movement and the final portion of their closing movement; to close the interrupter means during the continued opening movement of the respec tive switch blade so that when the switch blades are fully open their interrupter means are fully closed; to provide a circuit interrupter in series with each switch blade at the hinge end of each single pole switch assembly and to synchronize the opening and closing of the circuit interruptcrs with each other and with the operation of the switch blades by direct mechanical coupling of rotating insulator supports carrying the individual switch blades and interrupter mechanisms whereby the circuit is opened simultaneously at two places by the circuit interrupters followed by separation of the switch blades; to provide a single circuit interrupter in series with one of the switch blades at its hinge end to open the circuit followed by introduction of an air gap by separation of the switch blades; to provide stop means individual to each switch blade for arresting its opening and closing movements, the stop means being resilient to facilitate absorbing the shock incident to such operations; to mount each switch blade on a rotatable insulator and to provide additional stop means at the base of each insulator for arresting its opening and closing movements; and to provide a polyphase switch construction comprising a plurality of switch pole units, one for each phase, and to employ common means for effecting simultaneous operation of these several poles.

ground 12 a distance in accordance with the 3,1943% Patented July 13, 1965 in the drawings:

FIG. 1 is a top plan view of a support structure for a polyphase switch installation, the switches being omitted and only their stationary and rotatable supports being shown.

Fit 1A is a view, at an enlarged scale, showing certain details of construction of the rotatable insulator supports and stops therefor.

FIG. 2 is a view, inside elevation, or" the support structure shown in FIG. 1.

FIG. 3 is a top plan view of one pole of a polyphase switch construction inwhich the present invention is embodied, it being understood that three poles, identical with the construction shown in FIG. 3, are employed and are mounted on the switch operating structure shown in FIG. 1.

FIG. 4 is a view, in side elevation, of the switch pole as shown in FIG. 3, the distal or contact engaging ends of the switch blades being shown somewhat diagrammatically in order to avoid complicating the drawing with the contact structure and corona shield arrangement carried thereby.

FIG. 5 is a view, at an enlarged scale, andvin part in section showing the construction of the stop mechanism that is associated with the right switch blade and being a duplicate of the construction used for the left switch blade.

FIG. 6 is a horizontal sectional view taken generally along the line 6-6 of PEG. 5.

FIG. 7 is a perspective view of the switch pole construction shown in F168. 3 and 4-, the supporting base structure not being shown, the switch blades being shown in the closed position and an alternate stop mechanism employing a torsion bar construction being shown.

FIG. 7A is a horizontal sectional view taken generally along the line 7A-'7A of FIG. 7 to show in more detail the particular stop construction there employed.

FIG. 7B is a top plan view, at an enlarged scale, of the corona shieldssand contact arrangement at the ends of the switch blades in closed position.

FIG. 7C is a view, in side elevation, of the construction shown in FIG. 7B. 7

FIG. 8 is a view, similar to FIG. 7, taken at a slightly different angle and showing the switch blades in the open position. 7

FIG. 9 is a view of an underhung switch construction employing certain details of the present invention including a center break construction with a single circuit interrupter associated with one of the switch blades;

FIG. 10 is a bottom plan view of the construction shown in FIG. 9.

Referring now particularly to FIGS. 1 and 2 of the drawings, it will be observed that the reference character It} designates, generally, a support structure for a polyphase switch comprising three poles of identical construction the general details of which will be described hereinafter. The support structure 1% includes frame uprights 11 that extend into the ground indicated at 12. They are interconnected by longitudinal. frame members 13 to provide a rigid support structure with the longitudinal frame members 13 being elevated above the voltage rating of the switch structure to be described. it will be understood that other support structures can be employed and that the particular construction shown and described herein is byway of illustration only.

Extending across the longitudinal frame members 13 are three pairs of transverse support channels 14-14, each pair being employed to support one pole of the polyphrase switch structure. Stationary insulator supports l515 are mounted at the ends of each pair of support channels 14-14 for receiving stationary insulators to be described. Intermediate the stationary insulator supports 15-15 are rotatable insulator supports 16-16 which are suitably mounted in bearings on the transverse support channels 14-14. There are two rotatable insulator supports 16-16 for each switch pole and they are provided with radially extending operating arms 17-17 that are interconnected by an operating link 18. The ends of the operating link 18 are pivotally connected at 19-19 to the respective operating arms 17-17.

It is desirable that provision be made for limiting the rotary movement of the rotatable insulator supports 16- 16 and parts rotatable therewith. For this purpose, as shown more clearly in FIG. 1A of the drawings, the rotatable insulator supports 16-16 are provided with deteuts 20-20 which are arranged in the switch closed position to engage adjustable stops 21-21 in the form of screws and in the switch open position to engage adjustable screws 22-22. The adjustable stops 21-21 are carried by stop angles 23-23 mounted on one of the adjacent support channels 14 while the stop screws 22-22 are mounted on similar stop angles 24-24 mounted on the support channels 14-14.

Referring again to FIG 1, it will be observed that one of the rotatable insulator supports 16 for each switch pole is provided with a second operating arm 27 that is pivotally connected at 28 to one and of a link 29 the other end of which is pivotally connected at 311 to an arm 31 which is rotatable with a yoke 32 that is rotatably mounted about an axis 33 on the transverse support channels 14-14. The three yokes 32 are interconnected by interphase rods 34-34. It will be observed that the respective ends of the interphase rods 34 34 are pivotally connected at 35-35 to the ends of the yokes 32. An operating rod 37 extends from the left yoke 32, for example, and is connected to one arm of a bell crank 33 that is pivoted at 39 on the support structure 10. The other arm of the bell crank 38 is connected to a connecting rod 40 which extends to and is operated by a switch operator 41 which may be of any suitable type such as that shown in US. Patent No. 2,796,478, issued June 18, 1957, to John J. Mikos.

When the switch operator 41 is energized to move the connecting rod 40 downwardly in the direction indicated by the arrow 42, FIG. 2, the arrangement is such that the insulator supports 16-16 for each switch pole are rotated in opposite directions to initiate opening movement of disconnecting switch blades. However, before the circuit through the switch blades is opened, circuit interrupters are tripped to open the circuit at two places followed by separation of the switch blades to provide an air gap and then, as a part of the continued opening movement or downward movement of the connecting rod 40 under the control of the switch operator 41, the spring mechanism associated with each circuit interrupter is reloaded and the contacts of the respective circuit interrupter are reclosed. On operation of the switch operator 41 in a reverse direction to move the connecting rod 443 upwardly or in a direction opposite to the arrow 42, the insulator supports 16-16 for each switch pole are rotated in opposite directions and opposite to the directions in which they previously rotated for the purpose of closing the circuit by causing the switch blades to engage at their distal ends.

The details of construction of one of the switch poles are shown more clearly in FIGS. 3 to 8 of the drawings to which reference now will be made. Here the reference character 44 designates, generally, a switch pole construction which includes stationary insulators 45-45 that are mounted on the stationary insulator supports 15-15 which are carried by the transverse support channels 14-14 near their ends. In the particular construction shown the stationary insulators 4-5-45 extend upwardly and they carry line terminals 45-46 at their upper ends for connection to line conductors. Mounted on each or" the line terminals 45- 16 is a circuit interrupter that is indicated, generally, at 4'7 and may be of the construction disclosed in the patent first above referred to or in the application above referred to. Each circuit interrupter 47 includes series connected main separable contacts 48-48 and series connected auxiliary separable contacts 4-9-49 as shown by broken lines in the right circuit interrupter 47 shown in FIG. 4. As pointed out in the patent and application just referred to, provision is made in the operation of the circuit interrupter 47 to open a circuit for first opening the main separable contacts 4-5-48 and then opening the auxiliary separable contacts 49-4-9 to effect thereat the final circuit interruption. Auxiliary trip means also can be employed, as disclosed in application Serial No. 172,017, filed February 8, 1962, by Sigurd I. Lindell and Leonard V. Chabala, for tripping the circuit interrupter 4'7 simultaneously to open the circuit thereby at two places. Since the details of construction of the circuit interrupters 47-47 and the manner in which they are operated are all as set forth in the patent and applications just referred to, no further description thereof will be set forth herein.

At the ends of the circuit interrupters 47-47 away from the line terminals 45 45 there are provided metallie mechanism housings 50-50 through each of which a shaft 51, FIGS. 5 and 6, extends. The shaft 51, individual to each mechanism housing 50-51) is mounted on and is rotatable with rotatable insulators 52-52 that are mounted at their lower ends on the rotatable insulator supports 15-16. It will be understood that each metallic mechanism housing 5t) includes an operating structure under the control of the respective shaft 51 and rotatable insulator 52 for controlling the opening and closing functions of the circuit interrupters 47-47.

Mounted on and rotatable with the upper ends of the shafts 51 are switch blades 53-53 that are arranged to have contact engagement at their distal ends 54-54. It will be described hereinafter how the distal ends 54-54 of the switch blades 53-53 are provided with contact constructions and corona shields.

Each of the switch blades 53-53 extends radially from hub fittings 55-55 which are secured to and rotate with the respective shaft 51-51. At the upper ends of the shafts 51 there are mounted stationary terminals 56-56 which are shown more clearly in FIGS. 7 of the drawings. The stationary terminals 56-56 are connected by flexible conductors (not shown) to the respective hub fittings 55- 55 in order to provide a current carrying path of low resistance therebetween. The stationary terminals 56- 56 are connected to the metallic mechanism housing 50- 51 by means of L-shaped copper bar connectors 57-57 suitably brazed to L-shaped copper bar connectors 58- 58. As shown more clearly in FIG. 5 one leg 59 of each of the copper bar connectors 58 overlies the respective metallic mechanism housing 51) and is clamped thereto by means that will be described presently.

It will be understood that the masses of the rotating insulators 52-52 and the switch blades 53-53 rotatable therewith together with the parts mounted thereon are substantial. Since these elements are rotated at relativel y high speed, a substantial amount of energy must be dissipated at the ends of the switch opening and switch closing movements. In part, this is accomplished by the stop constructions previously described and located on the respective transverse support channels 14-14 in connection with rotatable insulator supports 16-16. However, it is desirable to provide additional stop means for further absorbing the energy incident to the arresting of the opening and closing movements of the switch blades 53-53 and associated parts. This construction is shown more clearly in FIGS. 5 and 6 of the drawings. Here it will be observed that a circular plate 62 is associated with each of the hub fittings 55 while a similar circular plate.

identical construction and each is provided respectively with a hub 64 and 65. As shown in FIG. 6 a key 65 serves to secure the hub 65 for rotation to theshatt 51. A similar construction is employed for securing the hub 64 to the shaft 51 above the mechanism housing 5h. Bolt holes 67 are provided as shown in the plate as for mounting it on the respective rotatable insulator 52. Similar bolt holes are provided for securing the circular plate 62 to the underside of the respective hub fitting The circular plates 62 and 63 are provided with de' pending and upstanding detents or studs 6?: which are spaced apart along a circle through a distance approximately corresponding to the extent of rotation of the respective shaft 51 and rotatable insulator 52. At the ends of their rotation the detents or studs sa ss are arranged to engage adjusting screws 69-69 which extend from blocks iii- 70 that are welded to the laterally extending ends of C-shaped' support plates 71-71. The C-shaped support plates 71-7l are secured to the mechanism housings Eli-450 by bolts 72. which extend through a suitable spacer '73, PEG. '5, a shock absorbing spacer M of suitable plastic material, and the leg 59 of the respective copper bar connector It will be understood that the adjusting screws 6969 can be shifted in order to engage the respective detents or studs 68d$ at the positions corresponding to the desired closed and open positions of the switch blades 53-53.

If desired, either the lower or the upper circular plate 62 or 63 can be omitted with a corresponding omission of the upper or lower portion of the respective C-shaped support plates'l'l. The support plates 71 of C-shape or L- shape can be of cast construction or they can be formed of rolled steel plate as circumstances may dictate.

A torsion bar stop mechanism is shown in FIG. 7A as an alternate to the stop plate construction shown in FIGS. 5 and 6. Here it will be observed in connection with FIG. 7 that an L-shaped torsion bar 77 is provided that may be formed of spring steel. A plate '78, corresponding to the central portion of the C-shaped support plate 71, is welded to the long leg 79 of the L-shaped torsion bar 77 and can be secured to the respective mechanism housing 5t by the bolts 72 in the manner previously described. The short leg Stl of the L-shaped torsion bar 77 is welded at its end to a block till which is similar to the block 7% previously described and is provided with adjusting screws til-82 for enga ing the detents or studs 686& in the manner previously described. It will be understood that the torsion bar 77, instead of being L-shaped can be C- shaped as shown for the C-shaped support plates 71 with a duplicate stop mechanism being provided on the lower end.

FIGS. 78, 7C and 8 show rnore clearly the constructions at the distal ends 54-54 of the switch blades 5353. Here it will be observed that a contact plate 85 is provided on one of the distal ends 54 for engagement with contact fingers $5 on the distal end 54 of the other switch blade 53 and within a sleet hood 87 to protect against ice. Arcuate outer upper and lower corona shields 8S and are carried by upper and lower L-shaped supports 9% and 91 on the distal end 5 of one switch blade 5'3 while arcuate inner upper and lower corona shields 92 and 93 are carried by upper and lower L-shaped supports M and 95 on the distal end of the other switch blade 53. The corona shields and supports are formed of aluminum to provide a minimum of weight.

in order to insure that the circuit through the switch blades 53-53 is maintained during the initial portion of their opening movement and the final portion of their closing movement upper and lower contact fingers 96 and 97, preferably of stainless steel, are mounted on the upper L-shaped support 9% in vertical and horizontal spaced relation and they extend into contact engagement with the inner upper corona shield 92 and well beyond it in the switch closed position. Their out turned ends 98- and SE9 facilitate engagement with the corona shield 92 when the switch blades 53 are swung to their closed position where the circuit is completed at this point. Since the distal ends 54 of the switch blades 53 are moving at high speed in the closing operation, there is a minimum of arcing incident thereto when they close on a circuit to which a load is connected.

It will be understood that the construction and arrangement of the corona shield 92. and contact fingers 96 and 97 are such that a circuit through the switch blades 5353 maintained during the initial rotary movement thereof to the open position and that this circuit is maintained by the engagement of the contact fingers 96 and 97 with the corona shield @2. for a time suthcient to permit the imultaneous operation of the circuit interrupters 47-47 to open the circuit in at least two places prior to the separation of the contact fingers 9-5 and 97 from the corona shield 92 with the result that the only arcing that takes place when they are separated is incident to the interruption of the relatively minute current that flows through the voltage dividing resistors in the circuit interrupters 4-747 when multigap units are used. Otherwise no arcingoccurs on opening the circuit.

As pointed out hereinbefore, the construction of the mechanism within the mechanism housings 5t 50 is such that on the continued rotation of the rotatable insulators 52-2 toward the open position, after the switch blades 5353 have separated, is such as to reclose the main and auxiliary contacts 48 and 49 in the circuit interrupters t7d7 and to recock the operating springs associated therewith. Thus in the switch open position shown in FIG. 8, the circuit interrupters 474l7 are in the closed circuit position but an air gap is provided between the mechanism housings 5il5tl since the switch blades S3-"3 extend substantially at right angles thereto. Now, when the insulators 52 523 are rotated in the closing direction, the switch blades 5353 are swung toward each other and the circuit is initially completed by arcing or prestriking between corona shields 83-92 and 89-93. This is followed by the plate engaging the contact fingers 86 in the sleet hood 87. Some arcing takes place, as pointed out, if the circuit is closed under load but the speed at which the switch blades 53-53 are closed is such as to reduce this arcing time to a minimum. Because of the speed incident to the closing operation, it is essential that stop mechanism, such as that described herein, be employed for arresting further movement of the switch blades 53-53 at the end of their closing movements.

When each switch pole construction 44 is in the fully open position, as shown in FIG. 8, for example, both circuit interrupters 47-47 are in their fully closed positions and their operating mechanisms are fully latched. The operating springs therein are fully tensioned in preparation for operating the respective main separable contacts 43-dtl and auxiliary separable contacts 49-49 to interrupt the circuit in two places by the circuit interrupters 47-47. In completing the circuit or closing it by operation of each of the switch pole constructions 44 by movement of the switch blades 5353 from their open positions to their closed positions shown in FIG. 7, a high speed is desired in order to create the least disturbance in the electrical transmission system to which the switch construction is connected and to cause the least damage to the contact plate 85 and contact fingers 86. The use of the two switch blades 5353, which provides a center break arrangement, permits the desired fast closing movement. However, in combination with a single circuit interrupter, as described hereinafter, or two circuit interrupters 47--47, it is essential that each switch pole construction 44 be capable of closing a loaded circuit so that load current immediately flows. Also consideration must be given to closing on a fault. In either case, the operation should be such that the continuously rated contacts comprising the contact plate 85 and the contact fingers 85 are not damaged. Also the closing operation should be accomplished without the creation of long uncontrollable arcs. It will be recalled that the switch blades 53-53 are provided with corona shields 88-89 and 9293 and that corona shield 92 functions as an arcing horn with the contact fingers 96 and 97 during the closing operation. They move toward each other at relatively great speed. In the pro-strike zone, the corona shields 3889 and 92-93 permit an arc to form between them at a distance where arcing horns, if used, would not be in physical contact. In the operation of the switch pole construction 44 it is important for maintaining a proper operating sequence to bring the auxiliary metallic contact provided by the contact fingers 96 and 97 into operation during the closing stroke to engage corona shield 92 so that, when the switch blades 53-53 are fully closed, the contact plate 85 is in complete engagement with the contact fingers 86 and the contact fingers 96 and 97 are in metallic contact with the corona shield 92 which also functions as an arcing horn.

In the circuit opening operation of each switch pole construction 44 the insulators 52-52 are rotated simultaneously because of the operating link 18 interconnecting them. The arrangement is such that each of the circuit interrupters 47 is tripped at the same time because of the mechanical coupling from each rotatable insulator 52 to the respective sets of main separable contacts 48-48 and auxiliary separable contacts 49-49. During these operations, and as a result of the rotation of the rotatable insulators 52-52, the switch blades 53-53 begin to swing to the open position. While this is taking place and while the circuit is being opened at two places by the circuit interrupters 47-47, it is imperative that the circuit be maintained through the switch blades 53-53. The circuit therebetween is maintained by the contact fingers 96 and 97 engaging the corona shield 92 while the switch blades 53-53 themselves are physically being rotated toward the open position. This contact engagement is maintained and the circuit therethrough remains uninterrupted until after the circuit interrupters 47-47 have completed their circuit opening functions. Thereafter the contact fingers 96 and 97 disengage the corona shield 92 when only the current flow through the voltage dividing resistors in the circuit interrupters 47-47 is required to be interrupted. Since this current is relatively small, no particular problem is involved with respect to it. The continued rotation of the insulators 52-52 swings the switch blades 53-53 to the full open positions shown in FIG. 8. During the latter part of the opening movements of the rotatable insulators 52-52, as pointed out, the circuit interrupters 47-47 are reclosed and their operating springs are recocked or recharged and all of the latches are reset.

FIGS. 9 and of the drawings show a modification of the switch construction illustrated in FIGS. 7 and 8 and described hereinbefore. Essentially the same arrangement is employed in the switch construction shown in FIGS. 9 and 10 except that only a single circuit interrupter is employed and the arrangement is intended to operate on a system energized at a lower voltage such as a voltage of the order of 115 kv.

As shown in FIGS. 9 and 10 the reference character 113 1 designates, generally, a switch construction in an underhung arrangement and carried by support channels 102- 102 It will be understood that the switch construction 1111 can be mounted in an upright position or in a vertical position as may be desired.

At one end of the support channels 1112-102 there is mounted a stationary insulator support 103 while spaced therefrom are rotatable insulator supports 1114- 104. Operating arms 1115-105 extend from the rotatable insulator supports 104-104 and they are interconected by an operating link 1%. The assembly is connected to an operating linkage 108. It will be understood that it may be connected in the manner hereinbefore de- 8 scribed in connection with FIGS. 1 and 2 of the drawings as a part of a three pole switch construction to be operated by a switch operator, such as the switch operator 41 above referred to.

Depending from the stationary insulator support 1113 is a stationary insulator 1119 which carries a line terminal 119. The rotatable insulators 111-111 are mounted on the rotatable insulator supports 104-104. A stationary terminal 112 is carried by the lower end of the right rotatable insulator 111 and it corresponds to the stationary terminal 56 previously described. A line terminal 113 is connected to the stationary terminal 112 for connection to a circuit conductor.

Switch blades 114-114 are mounted for rotation with shafts 115-115 which extend from the rotatable insulators 111-111 and are rotatable therewith. Mounted on the left rotatable insulator 111 is a metallic mechanism housing 116 which is arranged to be electrically connected to the switch blade 114 associated therewith in the manner previously described for the switch blade 53. Extending between the mechanism housing 116 and the line terminal 119 is a circuit interrupter 117 which corresponds in construction to that of the circuit interrupters 47 previously described.

The distal ends of the switch blades 114-114 carry separable contacts 118 and 119. In order to prevent arcing between the contacts 118 and 119 on opening or closing the circuit and to maintain it during the initial opening movement of the switch blades 114-114 and their final closing movement, an arcing horn 120 is mounted on an arm 121 on one of the switch blades 114 for engagement with a pair of arcing horns 122-122 on an arm 123 carried by the other switch blade 114.

In the switch construction shown in FIGS. 9 and 10 of the drawings the insulators 111-111 are rotated in opposite directions to swing the switch blades 114-414 out of contact engagement. Before they separate, the circuit interrupter 117 operates to open the circuit and interrupt any are incident to the current flow therethrough. The continued rotation of the insulators 111-111 is accompanied by rotation of the switch blades 114-114 to the open circuit position to provide the desired air gap in the circuit. While this is taking place the mechanism within the mechanism housing 16 is being recocked and the contacts of the circuit interrupter 117 are being reclosed.

What is claimed as new is:

1. A high voltage switch comprising, in combination, center break isolator switch means including a pair of switch blades each rotatably mounted at one end about an axis for contact engagement with one another at their distal ends, at least one circuit interrupter connected in series circuit relation with said isolator switch means, a first rotatable insulator connected to one of said switch blades to rotate conjointly therewith about its axis and mechanically connected to said circuit interrupter, a sec- 0nd rotatable insulator connected to the other of said switch blades to rotate conjointly therewith about its axis, linkage interconnecting said insulators for simultaneously rotating them and said switch blades in opposite angular directions from circuit closed to circuit open pom'tion and for operating said circuit interrupter to open the circuit, and interengaging contacts at said distal ends of said switch blades each including a load current carrying contact member at least one of which extends arcuately and transversely of the respective switch blade for maintaining the circuit between said switch blades during the initial opening movement of said switch blades and until after the circuit is opened by said circuit interrupter.

2. The invention, as set forth in claim 1, wherein means operated by the first rotatable insulator reclose the contacts of the circuit interrupter while the switch blades are being rotated to their open position, and the one load current carrying contact engages the other load current 9 carrying contact to complete the circuit by rotation of said switch blades to the switch closed position.

3. The invention, as set forth in claim 1, wherein a stop cooperates with each switch blade adjacent its axis of rotation to limit its rotation at the ends of its movement to the switch own and switch closed positions, and insulator means support each stop whereby each stop is energized at the potential of the respective switch blade.

4. A high voltage switch comprising, in combination, center break isolator switch means including a pair of switch blades each rotatably mounted at one end about an axis for contact engagement with one another at their distal ends, a circuit interrupter connected in series circuit relation with each switch blade of said isolator switch means, a first rotatable insulator connected to one of said switch blades to rotate conjointly therewith about its axis and mechanically connected to said circuit interrupter,

- a second rotatable insulator connected to the other of said switch blades to rotate conjointly therewith about its axis, linkage interconnecting said insulators for simultaneously rotating them and said switch blades in opposite angular directions from circuit closed to circuit open position and for operating the respective circuit interrupter to open the circuit whereby the circuit is opened at two places, and interengaging contacts at said distal ends of said switch blades each including a load current carrying contact member at least one of which extends arcuately and transversely of the respective switch blade for maintaining the circuit between said switch blades during the initial opening movement of said switch blades and until after the circuit is opened by said circuit interrupters.

5. The invention, as set forth in claim 4, wherein means operated by the respective rotatable insulator reclose the contacts of the circuit interrupters while the switch blades are being rotated to their open position, and the one load current carrying contact engages the other load current carrying contact to complete the circuit by rotation of said switch blades to the switch closed position.

6. The invention, as set forth in claim 4, wherein a stop mounted on each circuit interrupter cooperates with the respective switch blade adjacent its axis of rotation to limit its rotation at the ends of its movement to the switch open and switch closed positions, and insulator means supports each circuit interrupter and the stop mounted thereon whereby each stop is energized at the potential of the respective switch blade.

7. A high voltage switch comprising, in combination, an elongated support, a stationary insulator stack at each end of said support carrying a line terminal, a pair of intermediate insulator stacks rotatably mounted on said support between the end insulator stacks, a shaft extending from each intermediate insulator stack and rotatable therewith, a switch blade on each intermediate insulator stack connected to the respective shaft to rotate conjointly therewith about its axis for movement into or out of contact engagement with one another at the distal ends thereof, a metallic mechanism housing rotatably mounting each shaft and electrically connected to the respective switch blade, a circuit interrupter mounted on each stationary insulator stack and interconnecting the line terminal thereof and the mechanism housing adjacent thereto, means for operating each circuit interrupter by rotation of the respective shaft, and means for simultaneously rotating said intermediate insulator stacks to operate said circuit interrupters and open the circuit be tween said line terminals at two places followed by disengagement of said distal ends of said switch blades.

3. The invention, as set forth in claim 7, wherein stop means mounted on each mechanism housing and energized at the potential of the respective switch blade cooperate with the switch blade individual thereto for limiting the rotation thereof at the ends of their movements to the circuit open and circuit closed position respectively.

9. The invention, as set forth in claim 8, wherein the stop means includes a torsion bar for absorbing the impact grosses it) incident to arresting the switch blade by being stressed about its longitudinal axis.

10. The invention, as set forth in claim 8, wherein each shaft projects from opposite sides of its mechanism housing and carries a detent on each projecting end to engage the stop means carried by the mechanism housing and located in the path of the respective detent.

11. The invention, as set forth in claim 8, wherein additional stop means mounted on the elongated support cooperate with each rotatable insulator stack for limiting the rotation thereof at the ends of their movements to the circuit open and circuit closed position respectively.

12. A high voltage polyphase switch comprising, in combination, a plurality of elongated supports in coplanar parallel spaced relation each carrying one pole of the polyphase switch, each pole' including: a stationary insulator stack at each end of its support carrying a line terminal, a pair of intermediate insulator stacks rotatably' mounted on said support between the end insulator stacks, a shaft extending from each intermediate insulator stack and rotatable therewith, a switch blade on each intermediate insulator stack connected to the respective shaft to rotate conjointly therewith about its axis for movement into or out of contact engagement with one another at the distal ends thereof, a metallic mechanism housing rotatably mounting each shaft and electrically connected to the respective switch blade, a circuit interrupter mounted on each stationary insulator stack and interconnecting the line terminal thereof and the mechanism housing adjacent thereto, means for operating each circuit interrupter by rotation of the respective shaft, and means for simultaneously rotating said intermediate insulator stacks to operate said circuit interrupters and open the circuit be' tween said line terminals at two places followed by disengagement of said distal ends of said switch blades whereby each is opened as aforesaid by the switch pole individual thereto.

13. A high voltage switch comprising, in combination, an elongated support, a stationary insulator stack at one end of said support carrying a line terminal, first and second insulator stacks rotatably mounted on said support in spaced relation to each other and to said stationary insulator stack, a line terminal carried by said second insulator stack, a shaft extending from each of said first and second insulator stacks and rotatable therewith, a switch blade on each of said first and second insulator stacks connected to the respective shaft to rotate therewith about its axis for movement into or out of contact engagement with one another at the distal ends thereof, means electrically interconnecting said line terminal carried by said second insulator and the switch blade associated therewith a metallic mechanism housing rotatably mounting the shaft of said first insulator and electrically connected to the switch blade individual thereto, a circuit interrupter mounted on said stationary insulator stack and interconnecting the line terminal thereon and said mechanism housing, means for operating said circuit interrupter by rotation of its shaft by said first insulator, means for simultaneously rotating said first and second insulator stacks to operate said circuit interrupter and open the circuit between said line terminals followed by disengagement of said distal ends of said switch blades, and intcrengaging contacts on said distal ends of said switch blades each including a load current carrying contact member at least one of which extends arcuately and transversely of the respective switch blade for maintaining the circuit between said switch blades during the initial opening movement of said switch blades and until after the circuit is opened by said circuit interrupter.

14. A switch for use on a high voltage alternating current power circuit comprising, in combination, center break isolator switch means including a pair of switch blades each rotatably mounted at one end about an axis, main contacts on the distal ends of said switch blades for 1 1 contact engagement with one another in their closed positions, load current carrying auxiliary contacts on said distal ends of said switch blades at least one of which extends arcuately and transversely of the respective switch blade for maintaining a circuit through said switch blades during the initial portion of their opening movement and the final portion of their closing movement, a circuit interrupter having seperable contacts connected in series circuit relation with each switch blade of said isolator switch means, means mechanically interconnecting said switch blades for rotating them conjointly to move said main contacts and said auxiliary contact means out of and into contact engagement with each other, means connected to each circuit interrupter for opening and closing the contacts thereof, and operating means common to the switch blade operating means and to the circuit interrupter operating means to swing said switch blades to open position and to open said contacts of said circuit interrupters while the circuit is maintained through said switch blades by said auxiliary contact means and thereafter disengaging said main contacts followed by disengaging said auxiliary contacts.

15. The invention, as set forth in claim 14, wherein a corona shield is mounted on the distal end of each switch blade in spaced relation to each other and the respective main contacts whereby on closing movement of said switch blades when energized at normal voltage an arc is established between the corona shields in advance of the completion of the circuit through the auxiliary contacts.

References Cited by the Examiner UNITED STATES PATENTS 2,832,859 4/58 Gilliland 200-48 3,012,123 12/61 Richardson et a1. 20048 3,030,481 4/62 Gusson et al 20048 X KATHLEEN H. CLAFF Y, Primary Examiner. ROBERT K. SCI-IAEFER, Examiner.

Claims (1)

1. 7. A HIGH VOLTAGE SWITCH COMPRISING, IN COMBINATION, AN ELONGATED SUPPORT, A STATIONARY INSULATOR STACK AT EACH END OF SAID SUPPORT CARRYING A LINE TERMINAL, A PAIR OF INTERMEDIATE INSULATOR STACKS ROTATABLY MOUNTED ON SAID SUPPORT BETWEEN THE END INSULATOR STACKS, A SHAFT EXTENDING FROM EACH INTERMEDIATE INSULATOR STACK AND ROTATABLE THEREWITH, A SWITCH BLADE ON EACH INTERMEDIATE INSULATOR STACK CONNECTED TO THE RESPECTIVE SHAFT TO ROTATE CONJOINTLY THEREWITH ABOUT ITS AXIS FOR MOVEMENT INTO OR OUT OF CONTACT ENGAGEMENT WITH ONE ANOTHER AT THE DISTAL ENDS THEREOF, A METALLIC MECHANISM HOUSING ROTATABLY MOUNTING EACH SHAFT AND ELECTRICALLY CONNECTED TO THE RESPECTIVE SWITCH BLADE, A CIRCUIT INTERRUPTER MOUNTED ON EACH STATIONARY INSULATOR STACK AND INTERCONNECTING THE LINE TERMINAL THEREOF AND THE MECHANISM HOUSING ADJACENT THERETO, MEANS FOR OPERATING EACH CIRCUIT INTERRUPTER BY ROTATION OF THE RESPECTIVE SHAFT, AND MEANS FOR SIMULTANEOUSLY ROTATING SAID INTERMEDIATE INSULATOR STACKS TO OPERATE SAID CIRCUIT INTERRUPTERS AND OPEN THE CIRCUIT BETWEEN SAID LINE TERMINALS AT TWO PLACES FOLLOWED BY DISENGAGEMENT OF SAID DISTAL ENDS OF SAID SWITCH BLADES.

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