US2374703A - Electric switchgear - Google Patents

Description

May 1, 1945. F. w. REILLY 1 2,374,703

ELECTRIC swITcHGEAR @ww/MM@ A TTORNE Y -May 1, 1945. F. w. REILLY ELECTRIC SWITCHGEAR Filed Sept. 13, 1941 4 SheeLS-Sht-Bel 2 2 y. 0 y R L V. m@ m WW N Ow. r| K M T N 5 0dr M OMM WW J f 70u 1 m^ 2 4 Y ms/IU in B I l w am U mfw w O Mk, M a @wf 4 4 j n /|Cx|||n May l, l945.

F. \v. RE|LLY ELECTRIC SWITCHGEAR Filed Sept. 13, 1941 i Lif /al ATTORNEY May l, 1945- F. W. REILLY A 2,374,703

ELECTRIC SWITCHGEAR /jj @www ATTO R N EY Patented May 1, 1945 UNITED STATES PATENT QFFICE 2,374,703 ELECTRIC SWITCHGEAR Frank W. Reilly, Aubumdale, Mass.

Application September 13, 1941, Serial No. 410,718

Claims.

The invention relates to electric switching and. more particularly, to disconnect switches adapted to be contained in an enclosing compartment or cubicle. This application is a continuation in part of application Serial No. 364,149, filed November 4, 1940.

According to a preferred form of the invention, a disconnect switch is provided which comprises a grounded support journalling a switch shaft. Rigidly mounted on this shaft is a post type insulator which supports a movable switch contact. A stationary insulated contact is lprovided with which said movable contact may engage and disengage and a stationary insulated terminal is provided which is connected to the movable contact by a flexible conductor, such as a pigtail or sector plate. A plurality of such switches may be mounted on the same shaft to form a gang switch and, if desired, two or more gangs may be provided having ,suitable connections whereby all switches may be operated together or interlocked for independent operation.

Although this type of switch is capable of a wide range of uses in connection with switchboards and other places where it is desired to connect and disconnect electric conductors, it has an important use with switching apparatus which is enclosed in a compartment or cubicle.

This type of switching apparatus commonly includes a removable interrupting switch which may be cf the oil or air immersed type and the disconnect switch. In one preferred form of the invention the disconnect switch arm may be iournalled directly upon the circuit breaker frame and coact with stationary switch contacts mounted upon the cubicle frame. In another preferred 'form of the invention, the disconnect switch arm may be journalled upon the cubicle frame and may cooperate with stationary switch contacts mounted upon the terminals of the circuit breaker casing.

The invention also consists in certain new and original features of construction and combination of parts hereinafter set forth and claimed.

Although the novel features which are believed to be characteristic of this invention will be particularly pointed out in the claims appended hereto. the invention itself, as to its objects and advantages, and the manner in which it may be carried out, may be better understood by referring to the following description taken in connection with the accompanying drawings forming a part thereof, in which Fig. l is a side elevation, partly in section, illustrating the new switching apparatus;

Fig. 2 is a front sectional elevation taken on the line 2 2 of Fig. 1, with the removable switching unit removed;

Fig. 3 is a front elevation of the removable switching unit after removal from the cubicle;

Fig. 4 is a detail showing the device for locking the disconnect switch in open and closed positions;

Fig. 5 is a side elevation, partly in section, of a modiec switching apparatus using sector plates instead of pigtails;

Fig. 6 is an elevational section taken on the line 6 6 of Fig. 5; and

Fig. 7 is a plan section taken on the line 'l-l of Fig. 5.

In the following description and in the claims, various details will be identified by specicmames for convenience, =but they are intended to be as generic in their application as the art will permit.

Like reference characters denote like parts in the several figures of the drawings.

In the drawings accompanying and forming part of this specification, certain specific disclosure of the invention is made for purposes of explanation, but it will be understood that the details may be modified in various respects without departure from the broad aspect of the invention.

Referring now to the drawings, and more particularly to Figs. l, 2 and 3, the switching apparall, l2, shown in Fig. 3, normally rests and from which it may be moved outwardly out of the front of the cubicle by a suitable truck (not shown). The framework l2 of the removable unit carries individual insulating panels or barriers 59, 60, 6l, i

E2 and a handle I6 for operating the disconnect switch I3. The cubicle l0 is provided with a vertical space, indicated by I1, to accommodate the handle I6. It will be understood that, if desired, a series of such cubicles may be placed side by side in a manner known to those skilled in the art, with their` fronts in line, available for operation, inspection, and repairs. These cubicles may be used for general switching purposes, for connecting and disconnecting any suitable electrical apparatus and a source of electricity.

The cubicle Ill comprises a suitable steel framework denoted ln general by 22, covered by suitable steel panelling, the front indicated by I8, the back by I9, and the sides by 2l] and 2|. The steel framework is arranged to provide the operating space I'I. Secured to the framework are the pair of ways I4 extending from the front to the back of the cubicle. These Ways support the removable unit II, I2, as described hereinafter more in detail. The front I8 may be provided with a removable closure such as a door (not shown).

Mounted within the upper part of the cubicle I are three conductors 24, 25 and 26, forming part of a three-phase line. This line may be the incoming line supplying the electricity to the load through the switching apparatus forming part of this invention. Similarly, three outgoing conductors, all indicated by 21, are provided for supplying electricity to the load. All of the conductors 24, 25, 26 and 21 are mounted upon suitable post insulators, indicated in general by 28, these insulators being mounted upon the framework of the cubicle. These several conductors may lead to suitable busses or to feeders, or, in fact, the conductors 26 to 21 may be busses in themselves.

Circuit breaker II may be of any well known type, as for an example, an oil or air circuit breaker of high interrupting capacity, i. e., adapted to break the circuit under heavy load. In the form shown, oil circuit breaker I I is cf the threephase type having six terminals, three incoming terminals and three outgoing terminals. The incoming terminals are denoted by 38, 39 and 4I! and the outgoing'terminals are al1 indicated by 4 I.

The circuit breaker I I comprises a. switch frame 36 from which is detachably suspended the oil tank 3|. The switch frame 30 has secured thereto a pair of cross heads 32 adapted to rest on the ways I4 when the removable unit I I, I 2 is in place within the cubicle. The ways I4 have a series of holes I5, two on each side, in which are seated dowel pins 29 depending from cross heads 32. The operating mechanism for operating the circuit breaker II is denoted dagrammatically by 33, Supported on top of the switch frame 30 are bushings 48 supporting the terminals 38, 39, 40 and 4I. Forming part of the removable unit and supported by the circuit breaker I I is the framework I2. The framework I 2 carries bearings 42 and 43 for disconnect switch shafts 34. and 35, which carry insulators for the' various movable forked prongs indicated by 3'6-and 31. There are three prong contacts, all indicated by 36, corresponding to the three conductors of the three-phase system forming part of the incoming line, and three prongs, all indicated by 31 for the corresponding outgoing line. All of these forked prongs form part of a multiple gang, multiple pole switch. The poles are all identical so that it is only necessary to describe the one in detail.

The shaft 34 carries a support 44 which in turn carries a post type insulator 45 which carries the prongs 36. Secured to the prongs 36 is a plate 46 which has a pigtail 41 secured thereto extending to the terminal 40 of the circuit breaker II. Secured to the insulator 28 and in electric contact with the conductor 26 is a contact blade 49 adapted to enter between the prongs vor jaws 36 when the disconnect switch'is closed. The constructional details of the blades and forked prongs or jaws are discussed more in detail hereinafter.

For operating the gang switch, the handle I6 is secured to the end of an arml 50 secured to shaft 34. An arm is secured to shaft 35 and the two arms 50 and 5| are connected by a connecting rod 52. Thus by pulling down on the handle I6 inFig. 1, both gangs of prongs 36 and 31 are raised upwardly in the direction of the arrows A, contacting their respective blades 49 to close both gangs of the disconnect switch. It will be noted that the supportsA 4B swing into engagement with the adjacent structural members 53 in Fig. 1 to provide a positive stop to limit the downward movement of the disconnect switch.

For locking the disconnect switch in both open and closed positions, a suitable locking device may be` provided. This may take the form of a plate 55 suitably secured to the framework and having holes 56 and 51. A spring-pressed plunger 58 is secured to arm 50 which is adapted to engage in the hole 56 or 51. Thus a single locking device locks both gangs of switches in both open and closed positions.

For thoroughly insulating the several phases from each other and from the grounded cubicle, a series of insulating barriers 59, 60, 6I and 62 may be provided. These barriers may be of any well known dielectric material, such as transite, asbestos ebony, slate, Bakelite, etc., and are suitably secured as by angle irons, a'ngles, or the like, to the framework I2, as shown. These barriers all have clearance spaces 63 in their upper front and rear corners to clear the insulators 45. In addition, the two middle barriers 68 and 6| have clearance spaces 64 in their lower corners to clear the operating mechanism 33 of the oil circuit breaker II. The barriers eliminate all possibility of flash-over and also prevent the possibility of the flexible pigtail conductors 41 from swinging against each other or against the grounded cubicle frame.

In the ordinary use of the switching device, assuming that it is desired to withdraw the circuit braker II out of the cubicle for inspection or repairs, the cir-cuit breaker lII will first be opened to open the circuit. Locking member 58 will then be removed from hole 51. -The disconnect switch will then be opened by operating the handle I6 to open position, after which the locking device 58 is engaged in hole 56 to hold the switch in open position. A truck (not shown) will be wheeled into the cubicle and the entire removable unit II, I2 raised slightly to raise the cross heads 32 off the ways I4 to remove the dowel pins 29 from their holes I5. The removableunit will then be withdrawn on the truck out of the front of the cubicle where the circuit breaker will be inspected or repaired. To put the cubicle back into use, the removable unit II, I2 is then replaced by wheeling it in on the truck to position the cross heads 32 on top of the ways I4 and against the back of the cubicle. This aligns the dowels 29 with holes I5. The truck is then lowered and removed and the dowels 29 seat in the holes I5. This insures that the prongs 36, 31 will be in proper position to engage their blades 49 when the switch is closed. The disconnect switch is then closedl by lowering handle I6 in Fig. 1 and engaging the locking device'58 with hole 51 to hold the disconnect switch in closed position. The circuit breaker II is then also closed and the cubicle is' back in service.

Referring now to Figs. 5, 6 and 7, a similar type of switching apparatus is shown using sector plates instead of'pigtails. Also the barriers are carried by the switch shafts instead of by the circuit breaker frame. Here, as in the rst form, a cubicle 10 is provided, made up of suitable structural steel work with steel panels and having a removable unit. The removable unit is made up of the circuit breaker 1| and framework 66. 'I'he swinging arms carrying the movable contacts of the disconnect switch 13 are carried by the framework 66.

The cubicle 10 comprises a suitable steel framework 12 covered by suitable steel panelling, the front being indicated by 18, the back by 19, andthe sides by 80 and 8|. The steel framework is made to provide operating-spaces 11. The cubicle framework is also provided with ways 14 on which the removable unit 1| rests.

Mounted within the upper part oi.' the cubicle 10 are the three conductors, indicated by 84, 85 and 86, forming part of a three-phase line. These conductors may be the incoming line which supplies electricity to the load through the switching apparatus forming part of this invention. The three corresponding outgoing conductors are all indicated by 81. All of these conductors 84, 8l, 86 and 81 are mounted upon suitable post type insulators indicated by 83 mounted upon the framework ofthe cubicle. These conductors may form part of suitable busses or may be connected to busses.

The circuit breaker 1| may be of any well known type as in the case of circuit breaker in the first form, having three incoming terminals, indicated by 88, 89 and 90, and three outgoing terminals, indicated by 9|. 'I'he circuit breaker operating mechanism is indicated diagrammatically by 93, the switch frame by 94, and the detachable oil tank by 95. the circuit breaker frame are cross heads 96 adapted to rest upon the ways 14. Cross heads 96 carry dowel pins ||8 disposed in holes ||9 in ways 14 to insure holding the circuit breaker 1I and its framework 66 in correct position. Circuit breaker 1| and its frame 66 are removable by means of a truck (not shown) in a manner similar to the removable unit in the rst form.

Th circuit breaker frame 66 carries bearings 68 and 69 for the disconnect switch shafts |04 and |05 which carry insulators for the various movable sector plates or jaws, indicated by |06 and |01. There are three. sets of sector jaws, indicated by |06, corresponding to the three conductors of the incoming line. There are three sets of sector jaws, indicated by |01, for the corresponding outgoing line. All of these jaws form part of the multiple gang, multiple pole disconnect switch 13. The poles are all identical so it is only necessary to describe one set in detail.

Suitably secured to the shaft |04 is a support |08 which has anchored thereto a post type insulator |09 which in turn carries a pair of arcuate platesor jaws |06. These plates have inner and outer edges |20 and |2| of substantially circular configuration and the inner edges |20 are secured together and to the post insulator |09, forming bifurcated jaws. The radial edges |23 of the sector jaws |06 may be ilared divergently to assist making contact engagement with the stationary terminal blade ||2. The jaws |06 yieldably engage blade ||2 when the switch is closed and yieldably engage the blade on the circuit breaker terminal at all times.

The handle 16 for operating the disconnect switch is connected to arm 4 aflixed to the shaft |04. A similar arm ||5 is secured to a shaft and connecting rod ||6 connects the arms ||4 and ||5. Thus it will be seen that by moving the handle 16 upward in Fig. 5, both gang switches will move in the direction of the arrows B to open the disconnect switch. It will shafts, and have be noted that the radial edges |23 of jaws |06 swing into engagement with the abutment |03 to provide a positive stop to limit the upward movement of the disconnect switch. For limiting the lower position of the swinging arms of the disconnect switch, the support |08 may engage an abutment, corresponding .to the support 43 and abutment 53 in the ilrst form. Or, if desired, the barriers 91|00 may be permitted to swing against the wall of the cubicle tolimit the lower position of the switch.

A suitable locking device |22 may be provided for holding the disconnect switch in either open or closed position, similar .to that described in the first form and illustrated in Fig. 4.

A series of barriers of suitable insulating materials such as used in the rs't form are provided, these barriers being mounted by suitable vmeans directly on the shafts |04 and |05 of the disconnect switches. Four barriers are provided on each shaft, the two middle barriers 98 and 99 being disposed between the swinging jaws of the disconect switch and preventing arcing over between the several phases, and the two end barriers 91 and |00 .providing protection against ground. These barriers are generally of pie-shape .rigidly secured to their respective their radial and circumfer- V ential edges extending beyond the correspond- Secured to ing edges of the sector plates to provide better protection against iiash-over either between phases or between the several phases and ground.

It is thought that the use of this switching apparatus will be obvious to those skilled in the art from the explanation given above in connection with the iirst form. To remove thecircuit breaker 'H "it is rst opened by operation of mechanism 93, as will be understood by those skilled in the art. The disconnect switch is then opened by. swinging the handle 16 upward in Fig. '5, the disconnect switch being locked open for safety by engaging the spring-pressed member in the locking hole. The circuit breaker 1| together with its framework 66 is then removed by placing a. truck (not shown) in the cubicle under the circuit breaker andraising the cross heads slightly off the ways to disengage dowels ||8 from holes ||9 so that the circuit breaker can be easily withdrawn from the cubicle.

After the circuit breaker and disconnect switch are withdrawn, they may be inspected and repaired, if necessary, and then replaced. Stops |3 are provided on the w-ays 14 to assist in aligning the dowel pins ||8.and holes ||9. This insures locating the circuit breaker in the proper position so that the sector jaws of the disconnect switch will "be properly aligned with its terminal plates or blades ||2. Before the circuit breaker 1| is closed, the disconnect switch ymust be closed by swinging the handle 16 downward into the position shown in Fig. 5.

- As with the forked sector jaws |06, |01 in Fig. 5, the forked prongs 36, 31 in Fig. 1 will be of suitable construction to yieldably grip the blades disposed between them and may have suitable flaring ends to guide the jaws to closed position irrespective of any slight vrnisaligrirnent between the blades and the jaws. The blades 49 and I2 will be of suitable construction to cooperate with the bifurcated members to make good electrical connections.

There are many advantages in the present invention, both from a structural standpoint and from the standpoint of safety and operation. Al-

' though the disconnect switchv is shown used in a may swing in a vertical plane either up or down,I

as shown in the drawings, or it may be arranged to swing in a horizontal plane or at an angle, as for example 45 with the horizontal.

The disconnect switch may be adapted to existing apparatus with a minimum of change. For example, the stationary switch contacts may be located on existing bus bars, as shown and the contact arms and barriers may be adjusted along their shaftsV to correspond to the spacing of the stationary contacts. All of the several poles are separated -by insulating barriers which are mounted up'on the disconnect switch shafts so as to rotate with the switch, thus Iprotecting the poles and eliminating arc-over.

Ihe disconnect switch is susceptible of accommodation to various uses. It may be single pole 4or multiple pole, single gang or multiple gang.

It may -be single or multiple throw. 'I'he various contacts and shafts may be operated individually or may be operated simultaneously through appropriate linkage, as shown.

The operating shafts may be of metal and may be thoroughly grounded, entirely eliminating the necessity for insulated operating linkage. The operating shafts may be grounded through their bearings as shown or by any other suitable means. Since there are no insulators directly surrounding the switch contacts, full visibility of the contacts is enjoyed at all times. The switch is especially strong since both the stationary and movable contacts are directly mounted upon post type insulators and, when the switch is closed, increased cantilever strength is obtained. The switch provides a straight path for the electric current and because of its relation to the rest of the circuit has minimum tendency to open under short circuit.

The use of this disconnect switch in a metal cell or cubicle has many advantages. It permits the withdrawal of the breaker without breaking any cable connections. The breaker can also be electrically .opened without withdrawal. The breaker tank may be removed without withdrawal of the breaker. The swinging arm of the disconnect switch being mounted on the breaker frame, it becomes removable with the circuit v breaker for inspection and maintenanceyin addition. the jaws 36, 3l and H16, IUT which require attention from time to time, are exposed for convenient adjustment and repair. Also, the movable jaws fall away from the upper contacts, which makes the disconnect switch doubly safe. Furthermore, the fixed contacts may be mounted directly upon the bus or upon the insulator supporting the bus, as shown in Fig. 1.

The sector jaws of Figs. to '7 have numerous advantages over the fiexible pigtail connections used in Figs. l to 4. The construction is simpler and more rugged, and all danger of the pigtails swinging against parts of different potential is eliminated. They also have the advantage of permitting engagement with other contacts (not shown) for bridging, for connecting to a transfer bus, for grounding, or for any other purpose. The rotating barriers simplify the construction and facilitate assembly.

While certain novel features of the invention have been disclosed and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes may be made by those skilled in the art without departing from the spirit of thel invention.

What is claimed ls:

l. In enclosed electric switching apparatus, a cubicle, a circuit breaker in said cubicle and removable horizontally therefrom, said circuit breaker and said cubicle each having mounted thereon a set of fixed disconnect switch terminals, said cubicle terminals being mounted above said circuit breaker terminals to provide generally vertical air gaps, movable bridging switch contacts movable inA paths generally lengthwise of said air gaps to bridge said sets of terminals and to disengage at least one set of terminals, a grounded metal operating shaft extending horizontally across the cubicle, insulators rigidly attached to said shaft and t0 their respective movable bridging contacts to form cantilever switch arms, operating devices secured to said shaft, said shaft being disposed at such point that, when force is applied to said operating devices, said cantilever arms carry their movable contacts in the paths aforesaid.

2. In enclosed electric switching apparatus, a cubicle, a multi-phase circuit breaker mounted in said cubicle and removable horizontally therefrom, said circuit breaker and said cubicle each having mounted thereon a set of incoming and outgoing disconnect switch terminals corresponding to the phases, said cubicle terminals being mounted above said circuit breaker terminals to provide generally vertical air gaps, movable bridging switch contacts movable in paths lengthwise of said air gaps to bridge said sets of terminals and to -disengage at least one set of terminals, a grounded incoming metal operating shaft and a grounded outgoing metal operating shaft both extending horizontally across the cubicle, post insulators rigidly attached to their respective shafts and to their` respective movable bridging contacts to form cantilever switch arms, operating devices secured to said shafts, said shafts being oiset from points intermediate the length of their respective air gaps at such distance that, when force is applied to said operating devices, said cantilever arms carry their movable contacts in the paths aforesaid.

3. In enclosed electric switching apparatus, a cubicle, a multi-phase circuit breaker mounted in said cubicle and removable horizontally therefrom, said circuit breaker and said cubicle each having mounted thereon a setof incoming and outgoing disconnect switch terminals corresponding to the phases, said cubicle terminals beingv mounted above said circuit breaker terminals to provide generally vertical air gaps, disconnect switch contacts movable lengthwise of said air gaps to engage and disengage one set of terminals, said movable switch contacts including conductors extendible to the other set of terminals, an incoming metal operating shaft and an outgoing metal operating shaft both extending horizontally across the cubicle, post insulators rigidly attached to their respective shafts and to their respective movable contacts to form cantilever switch arms, operating devices secured to said shafts, said shafts being offset from points intermediate the length of their respective air gaps at such distance that, when force is applied to said operating devices, said cantilever arms carry their movable contacts in the paths aforesaid, and sector shape insulating barrier plates rigidly mounted on said shafts and located between the several movable contacts and the adjacent walls of the cubicle and extending radially beyond their corresponding movable contacts.

4. In enclosed electric switching apparatus, a cubicle, a multi-phase circuit breaker mounted in said cubicle and removable horizontally therefrom, said circuit breaker and said cubicle each having mounted thereon a set of incoming and outgoing switch contacts corresponding to the phases, said cubicle switch contacts being mounted above said circuit breaker switch contacts to provide generally vertical air gaps, movable bridging switch contacts movable lengthwise of said air gaps to bridge said sets of switch contacts and to disengage said cubicle switch contacts, an incoming metal operating shaft and an outgoing metal operating shaft both journaled on said circuit breaker, said shafts extending horizontally across the cubicle, post insulators rigidly attached to their respective shafts and to the midpoints of their respective movable bridging contacts to form cantilever switch arms, operating devices secured to said shafts, said shafts being oilset from points intermediate the length of their respective air gaps at such distance that, when force is applied to said operating devices, said cantilever arms carry their movable contacts in the paths aforesaid.

5. In enclosed electric switching apparatus, a cubicle, a multi-phase circuit breaker mounted in said cubicle and removable horizontally through the front thereof, said circuit breaker and said cubicle both having mounted thereon sets of forward and rearward switch contacts corresponding to the phases, said cubicle switch contacts being mounted above said circuit breaker switch contacts to provide generally vertical air gaps, forward and rearward movable bridging switch contacts movable lengthwise of said air gaps to bridge said sets of switch contacts and to disengage said cubicle switch contacts, a forward metal operating shaft and a rearward metal operating shaft both joumaled on said circuit breaker, said shafts extending horizontally across. the cubicle from left to right, post insulators rigidly attached to their respective shafts and to the midpoints of their respective movable bridging contacts to form cantilever switch arms, operating devices secured to said shafts, said shafts being offset from points intermediate the length of their respective air gaps at such distance that, when force is applied to said operating devices, said cantilever arms carry their movable contacts in the paths aforesaid, sector shape insulating barrier plates rigidly mounted on said shafts and located between the several movable contacts and 7the adjacent cubicle structure, said barriers exte ding from front to rear and extending radially beyond their corresponding movable contacts.

FRANK W. REILLY.

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