US2331632A

US2331632A - Switchgear

Info

Publication number: US2331632A
Application number: US319889A
Authority: US
Inventors: Gordon F Sauers
Original assignee: Westinghouse Electric and Manufacturing Co
Current assignee: CBS Corp
Priority date: 1940-02-20
Filing date: 1940-02-20
Publication date: 1943-10-12
Anticipated expiration: 1960-10-12
Also published as: DE940126C

Description

G. F. SAUERS Oct. 12v, 1943.

` sWITcHGEARs Filed Fb. 2o. 1940 s' sheets-sheet 2 fe. suv

INVENTOR fardoff/Jaz/ers BY q. ATToRNE w 1TNEsE: MMM/. v Q. 7. MA

Oct. 12, l1943. G. F. sAul-:Rs

SWITCHGEARS Filed Feb. 20,

3 Sheets-Sheet 3 INVENToR ardo/r {Jal/ers.

Ano @a4/Z Q/ RNEY WITNESSES:`

A Patented 12, 1943 Gordon F. Sauers,

Pittsburgh. lia., signor to Westinghouse Electric & Mannfactnrinrcompany, East Pittsburgh, Pa.. a

Pennsylvania corporation of Appurauon February zo, 194e, serial No.' 319,889 somma. (ci. zoo-16s) My invention relates, generally, to electric circuit interrupting devices, and more specifically to disconnecting switches.

In order to obtain better electrical contact between the blade and contacts of disconnecting v switches, high contact pressures havebeen found desirable. The use.v of high contact pressures in a disconnecting switch, however, requires the application of a. considerable force to move the switch blade. In the ordinary type of disconnect switchfwhere a blade is pivoted'on a hinge conanism to operate them.

tact for movement into and out of engagement with a break contact, the force necessary to move the blade due to the friction at the hinge contact is of a high value, and at the initial opening and final closing movements of the blade it is also necessary to overcome the friction at the break contacts. Thus,for relatively high capacity switches the force required to operate the switch may be' high enough to prohibit direct manual operation.

Various schemes have been -proposed in attempting to overcome this difilcuity such as the provision of force multiplying mechanism for actuating disconnecting switches, and limiting the contact areas of the switch. The iirst scheme provides an added cost in the form of additional mechanism for the switch, and the latter scheme while reducing the friction at the instant of opening and closing of the switch, does not eliminate friction at the hinge contacts.

One object of.my invention, therefore, is to provide a disconnecting switch utilizing highment of the switch blade, so that but a negligible force isl required to move the blade during the major portion of its opening and .closingmovements.

a novel type of disconnecting switch having a limited-area high-'pressure contact construction requiring but a relatively small movement of the switch blade to entirely engage or diseii'gage the contacting portions thereof. l

A further 'object of my' invention is to provide a disconnecting switch having a novel movable A further object of my invention is to provide pressure contacts,v all of which are-entire1y disengaged and engaged by a relatively slight movemounted in metal cells or compartments, space 4considerations are important, and although the ordinary type of, disconnect switch may be mounted in a cell with a'. breaker, suchswitches embodying a blade pivoted on one contact and having high-pressure contacting portions, re-- quire considerable'space for their operation, and may require additional force multiplying mech- Accordingly, it is another tion to provide a novel type of disconnect switch so constructed as to require but a relatively small space for mounting` and operation.

A further object of my invention is to provide a novel form `of disconnect switch which is particularly constructed and adapted Ifor mounting in a cellwith a circuit breaker. l

Another' :bject of -myinvention is to provide a disconnect Vswitch with novel locking means for locking the switch in an open or closed position.

A still further object of my invention -is to.

provide in an arrangement where a disconnect switch is provided in a circuit leading to a circuit breaker, novel interlocking means for preventingY opening or closing of .the switch unless the circuit breaker is open.

Theser and other objects of my invention will become more apparent upon consideration of the following speciiication of preferred embodiments thereof taken in connection with the attached drawings, in which:

Figure 1 is a side view of a disconnecting switch construction illustrating one embodiment ofmy invention;

Fig. 2 Yis a transverse cross-sectional view through the switch construction shown in Fig. 1 and taken substantially on the linev II-II thereof;

Fig. 3'is a front end view of the switch handle removed, and showing a modi- 'iled locking means for the switch; y

Fig. 4 is a top view or the switch construction shown in Figs'. 1 and 2;

Fig. 5 is a diagrammatic view illustrating an electrical interlock between my novel switch and a circuit breaker; and

Fig. 6 is also a diagrammatic view illustrating object of my inven- Y the switch sham).-vr Vin Fig. l1 takenjust inside the front panel, with` wall 8 of the metallic cell or housing as by the.

machine bolts I0. Suitable tapped spacers I I are interposed between the housing wall 8 and the frame wall 6 and secured to the wall to threadedly receive the bolts I and to space the switch frame .from the housing wall. An angle bar I2 is secured between the free ends of the

frame sides

2 and 4 in any suitable manner such, for exbeing received between one arm 50 of each pair of supporting arms on the supporting bracket 4l and the spacing member -52 of the bracket, to thereby support the blade sides in proper spaced relation. Securing pins 58 are passed through apertures in each pairof supporting arms 50 and through the blade to secure the blade to the bracket 48, and the pins 58 are secured in posiample, as by welding or the like. The connecting portion 6 ofthe frame, supports the spaced insu lators I'4 which are, in turn, suitably secured at substantially the mid-portion of this frame member, as by the screws I6. The opposite ends of the insulators I4 carry contact tongues I8 secured to the insulator caps in any suitable manner, such as by the machine Screws 20. Each contact tongue I8 has a contact portion projecting forwardly beyond the insulator I4, and a laterally extending terminal portion 22 for the connection of a'circuit conductor thereto.

The other contacts of the switches illustrated in the drawings are formed by spaced bus bars 24 supported from the angle bars I2 of the frame by spaced insulators 26, seated on top of the bars. Each insulator 26 has secured to the top end thereof an angular bracket 28 to which is secured a bus bar 24. The brackets 28 are secured to their respective insulators 26 and bus bars 24, as by the bolts 30. v ,i y

Bolted to the vertical face of the supporting angle bar I2 are spaced bearings 32 adjacent the opposite ends thereof as viewed in Fig. 1. Each bearing 32 includes the

bearing halves

34 and 36 adapted to be -bolted together and to the angle bar I2 by the bolts 38. A switch actuating shaft 40, is square in cross-section throughout its length except for spaced rounded journal portions adapted to be received in the bearings 32. The shaft 40 is supported by the bearings 32 and is prevented from endwse movement by the squared portions of the shaft which extend radially beyond the rounded journal portion thereof to engage opposite sides of bearings 32.

Blade supporting insulators 42 are directly secured to the shaft 40 in spaced relation at points substantially opposite the respective contacts I8 and bus bars 24. The insulators 42 are secured to the shaft as by bolts 44 passing directly through the shaft to be threadedly engaged in the end caps of the insulators 42. As appears from Fig. 1, each insulator 42 is secured to the shaft 40 by means of two bolts 44, and the vertical side of the supporting angle bracket I2 is provided with apertures 46 which, in the closed position vof the switch, are positioned to be in alignment with the bolts 44 so as to render them readily accessible and visible. Each of the blade supporting insulators 42 has a blade supportingbracket 48 secured to the free end cap thereof, and each bracket includes spaced pairs of spaced arms 50 for receiving therebetween the split blade member 56. Between the arms of each pair of arms 58 is provided a spacing member 52 spaced from the arms and of a lesser extent than the arm. The blade 56 is of the split type, and. includes the spaced blade sides 54 with each side tion in any desired manner, such,'for example, as by the use of cotter pins, as shown. At opporsite ends ofthe blade 56, I have provided boltspassing through the blade sides for securing them together with an interposed spacer sleeve 62 on the .bolts 60 between the blade sides to maintain them securely in proper spaced relation. The bolts 60 likewise support spring washers B4 at the outer sides of the blade to provide for prede'- termined contact pressure. The contacting' portions of each blade are provided with raised, limited-area contact portions, as seen particularly in Figs. 2 and 4, which are in the form of longitudinally extending relatively sharp edged ridges. 'This type of limited area contact portion is the same as that disclosed in the copending application of Herbert J. Crabbs, Serial No. 268,906, filed lApril 20, 1939, now Patent No. 2,262,168, issued November 11, 1941, and assigned to the same assignee as this application. However, in the switch disclosed Vherein the ridges of the limited contact portions 66, extend longitudinally of the blade sincethe opening and closing movements of the blade are generally in a direction substantially parallel with the longitudinal axis of the blade.

In the structu're thus far described, it is apparent that I have provided a gang-operated switch havingspaced sets of spaced stationary contacts, one of the contacts of each set being formed by a busbar, and having bridging Ycontacts for each set of spaced contacts, which are mounted on a single operating shaft 40. The switch as illustrated in the drawings is shown in closed position, and when it is desired to open the switch, it is obvious that but a slight movement is necessary from the full line position, as

shown in Fig. 2, to the dotted line position adjacent thereto, Where the limited area raised contact portions 66 of the switch blades are completely disengaged from their respective contacts. -Upon continued movement of the switch blades to the lower dotted line position shown in Fig. '2, itis obvious that the upper ends of the blades move downwardly in an arcuate path away from the upper contact or bus bars 24, and with a relatively telescopic action with respect to the lower contacts I8. The movement between the two dotted line positions shown in Fig. 2 is substantially unopposed by any substantial frictional forces 'since the only resistance encountered will be the friction of the operating shaft 40 in its bearings, inasmuch as the blade sides 54 are spaced apart a distance greater than the thickness of the fixed contact I8. However, if there be any disalignment of the parts, obviously the xed contact I8, since it remains in the space between the'blade sides 54, will act as a guide means for the blade in its opening and closing movements. Upon movement of. the switch from its fully open position, or the -lower dotted line position shown in Fig. 2, t0 close the switch, it is obvious that the major portion of movement of the switch, or that portion of movement between the lower dotted line position shown in Fig. 2 and the upper dotted line position, may be easily accomplished without exertion of any substaning movement of the switch blades wherein their raised contact portions 66 Iengage the fixed vcorl-v tacts, is that portion of movement between they ...upper dotted line position shown in Fig. 2, and

the full line position, which obviously is but an extremely minor portion of the entire switch closed position, it should benoted that the bolts 60 which secure the sides 64. of the split blades 56 together, are both positioned on the'same or lower side of the xed contacts I8 and 24,'-as viewed in Fig. 2, thereby permitting opening and closing movementsof the switch in the manner, indicated. Iniother words, -the switch can be moved buta slight amount in the' closing direc.- tion beyond the closed position shown in Fig. 2, before the spacing sleeves onthe bolts 60 engage the bus b ar 24 and fixed contact |8, respectively.

It should also be noted that the magnetic forces present in my novel switch tending to blow open the switch upon the passage of heavy cur- Y blade movement.` When the switch is moved to rents therethrough is considerably less than the.v

value of themagnetic forces present in the conventional type of switch where a blade is pivotally mounted on one contact. This is due to the fact that one contact of my switch, namely the bus bars 2 4, extend at-right angles to the blade 5 6 on opposite sides thereof, so that equal magnetic forces at the upper end of the blade are in opposition, thus neutralizing each otherl and eliminating any forces from the upper end of the blade entirely.

As seen particularly in Fig. 1, operating shaft 40 is provided adjacent its forward end with a stop pin 68 suitably secured in an aperture in the shaft and projecting radially outwardly from the shaft, for cooperation with spaced fixed stop .pins 12 securedin the side 2 of the U-shaped switch supporting frame. The stop lugs 12, asappears from Fig. 3, are spaced apart so `as to define the limits of rotary motion of the operating shaft 40 for the switch. As seen in Fig. 1, the vertical side of the supporting angle bar I2 is provided with an aperture 10, which in the closed position example, as by welding or the like.'A t A coil compression spring 86 isf provided over the actuating shaft 40 between the' side 2 of the switch support- 'ing frame, and the

locking collar

8,8, to thereby normally urge the .collar 88 to. the'left, or outwardly of the switch structure as viewed in Fig. 1. As further shown in Fig. 1, the outer end 'of the actuating shaft 40 terminates adjacent to-an enlarged aperture in the front wall 98 of the cell or housing in which the switch is mounted, and

an operating handle having a squared socket portion for receiving the squared end of the shaft may be provided on the outer end of the shaft for manipulation from the front of the panel.

` In the closed and open positions of the switch,"-

the locking pin 84 -is positioned to be in'alignl ment with 'one of the apertures 92 in the locking collar 08, and in either of these positions of the' switch, the coil compression spring 86 will normally urge the locking col1ar|i8 to the left to the dotted line position shown in Fig. 1 so that the locking pin 04.1s received lin the corresponding apertureJ 02. This will lock the switch against actuation until a force is applied 'to the handle e in an inward direction, in the direction of the arrow shown in Fig. 1, to move the thrust collar its open or closed position and locked with the of -the switch aligns with the pin 68 on the oper- At the forward end of the Ushaped supporting frame and secured to the side l2 of the frame is a bracket member 14 having offset flanges 18 .on two adjacent sides thereof which are secured to the frame side 2 as 'by the bolts 18, to space the bracket 14 from the frame side 2. The bracket 14 includes an aperture aligned with the actuating shaft 40 in its vertical wall, 'and in its horizontal wall, as viewed in Fig. 1, there is provided a small aperture aligned With the opening in a sleeve 82 secured to, and depending from this wall of the bracket for the reception of a plunger locking member hereinafter to be further described. Slidably but non-rotatably mounted on the actuating shaft 40, as by the provision ofa squared aperture therethrough correspondthe bracket 14 in any suitable manner, such for 86 and thereby, by way of the tie rods 90, the.

locking collar 88 to the position shown in full lines, Fig. 1. )Thiswill remove the'aperture in' the locking collar 88 from the locking pin 94 and permit rotation of the 'actuating' shaft 40 vby means of the handle |00. This operation can be performed provided the plungerlocking member 84 is in the lower position shown in full lines in Fig. 1. However, assuming the 'switch to be in locking pin 94 received in one of the. apertures 02 in thelocking. collar 88, then ifthe plunger lock 84 is in an upper position, shown in dotted lines in Fig. 1, such that it lies behind, or to the right of the lower end of the locking collar 88, then it will be impossible to manually move the operating handle |00 inwardly in the direction ofthe arrow shown in Fig. 1 to release the switch for rotational movement.

One form of control means for the plunger lock 84 is shown schematically in Fig. 5, and partially in Fig. 3. As before stated, the disconnecting switch construction illustrated is particularly adapted for mounting in a cell or cubicle-l for housing a circuit breaker, and is adapted to connect the circuit breaker to its supply circuit, the object being `to enable disconnection of all partsof the circuit breaker from its source of supply to enable removal or repair of the vbreakl er. Since the disconnecting switch construction illustrated is not adapted to the opening of load currents, it isvnecessary to provide some sort of interlock between the breaker and disconnecting switch to prevent opening or closing of the switch unless the breaker is open. This may be accomplished by an electricalinterlock as shown in Figs. 3 and 5, where the numeral |02 indicates a pair of spaced line contacts in the circuit |05, which are adapted to be bridged by a movable circuit breaker bridging member |04.v The movable circuit breaker bridging member is provided with an auxiliary bridging contact |06 for controlling a separately energid control circuit having the spaced contacts 08 positioned to be engaged by the bridgingA contact |06 when the circuit breaker is opened. This independently energized control-circuit includes asolenoid ||0 which may be mounted on the side 2 of the switch supporting frame, as shown in Fig. 3, the

plunger of which is pivotally connected to one end of the lever |`|2, the other end of which is pivotally connected as at ||6 to the lower endof the plunger lock 84 slidably mounted in the sleeve 82. The lever H2 is pivoted as at I I4 on the side 2 of the switch supporting frame, and is maintained normally in the position shown in Fig. 5 by a coil tension spring H8 secured to the end of lever ||2 to which the plunger of solenoid ||0 is connected, with the spring |l8 anchored to the fixed housing for the solenoid as shown in Fig. 3.

AThus, in the closed position of the circuit breaker'illustrated in Fig. 5, the solenoid ||0 is not energized and the coil tension spring H8, aided by the force of gravity acting on the solenoid plunger and parts atfthe corresponding end of lever H2, acts to maintain the lever I l2 in the position shown and thereby maintain the plunger lock 84 in its uppermost position'. As explained heretofore, when the Ii'unger lock 84 is Vin its uppermost position, it p" events movement of the locking collar 88 inwardly 40 in the direction of the arrow shown in Fig. 1, thereby .preventing removal of the aperture 92 4in the collar 88 from'the locking pin 94 on the bracket 14, thereby positively locking the disconnecting switch in its closed or open position so long as the circuit breaker remains closed. Now, as the circuit breaker is opened, the bridging contact |06 carried by the movable breaker contact support acts to bridge thecontacts |08 of the control circuit to energize the solenoid ||0, to move the plunger thereof upwardly, and thereby the lever ||2 in a clockwise direction as viewed in Fig. 5, against the tension of spring |8 to withdraw the plunger lock 84 from behind the locking collar 88 to thereby permit lmanual release of the switch locking means by longitudinal movement of the handle |00 in the direction ofthe arrow shown in Fig. 1, to move the aperture 92 in the locking collar 98 away from the locking pin 94 and permit opening or closing of the switch as described heretofore, only when the circuit breaker is in its open position.

Another form of interlock which may be used with my switch construction illustrated in Figs. 1 to 4 is a simple mechanical interlock illustrated in Figs. 1 and 6,. As shown in the figures, the bridging contact |04 of the circuit breaker directly pivoted to a substantially V shaped lever |20 pivotally mounted as at |24 on a xed pivot. 'Ihe outer end of one leg of the lever |20 is pivoted tothe movable bridging contact |04 of the circuitbreaker and the outer end of the other leg of the v-shaped lever |20 is adapted to abut against the lower end of the plunger lock 84.

Thus, when the circuit breaker is closed as shown at Fig. 6, the plunger lock 84 is maintained in an upper position by the lever |20. However, when the circuit breaker is opened, it is obvious that the lever |20 will be rotated in a counter-clockwise direction as viewed in Fig. 6 about its fixed pivot 24 to thereby permit the plunger lock 84 to move downwardly and permit opening or closing of the disconnecting switch in the same manner described above.

From the foregoing it should be obvious that I haveprovided a novel form of disconnecting switch requiring but a small space for its operation, and requiring but a relatively small movement to fully engage or disengage the contacting portions thereof, so that the major portion of the opening and closing movements of the switch blades require but a relatively insignificant eil'ort to move the blade.

Although I have illustrated and described 'my novel form of switch as being particularly adapted for mountingin a cell-With a circuit breaker and as having certain particular novel cooperation with a circuit breaker, it is obvious that certain features of the switch are also adapted illustra for general application and in other applications where minimum space requirements are important. Y

Two forms of interlocking means have been disclosed which` cooperate with switch locking means to prevent opening of the disconnectingswitch unless the circuit breaker which it controls h previously been opened. Also, I vhave d a disconnecting switch for use with a bus bar as one contact of the switch and having'many other novel features al1 as heretofore described and illustrated in the accompanying drawings.

of the actuating shaft Having described preferred embodiments Aof my invention in accordance with the patent statutes, I desire that my invention be interpreted as broadlyI as possible, inasmuch as it will be obvious, particularly to persons skilled in the art, that many changes and modifications may be made in the particular structures 'disclosed herein without departing from the broad spirit and scope of my invention. Therefore, I desire that the following claims be broadly construed and that they be limited only by what is expressly stated therein.

I claim-as my invention:

1. lIn a device of the character described, an open substantially rectangular supporting frame, insulating mea-ns carrying a contact in the frame and mounted on one side thereof, other insulating means carrying a switch blade member movably mounted in said frame adjacent the opposite side thereof, a bus bar spaced from said frame and extending across an open side thereof so that said blade member is movable through said frame into and out of bridging relation with said contact and bus bar.

2. In a device of the character described, an

open substantially rectangular supporting frame,

insulating means carrying a contact in the frame and mounted on one side thereof, other-insulating means carrying a switch blade member movably mounted in said frame adjacent the op-4 posite side thereof, a bus bar spaced from said frame and extending across an open side thereof soL that said blade member is movable through said frame into and out of bridging relation with said contact and bus bar, and insulating means supporting said bus bar from said frame.

3. In a switch, a pair of spaced contact members, a movably mounted split blade member adapted in the closed position of the switch to bridge said contact members with said contact mem rs received between the sides of said split blade member, said blade member having spaced raised limited area contact portions for engaging said contact members at the closed position of said switch, and spaced means for securing the sides of said split blade member together positioned on corresponding sides of said contact members, respectively, so as topermit movement of said blade member along a line from one of said contact members passing through the other of said contact members, and for limiting movement of said blade member into engagement with said contact members so that in the closed position of the-switch said contact portions engage the parts of said contact members adjacent the edges thereof facing the path oi opening movement of said blade member.

4. vIn a switch, spaced contacts, a split blade member having spaced, raised, limited-area contact portions for engaging said contacts, respectively, in the closed position of the switch, said v blade being mounted for movement to engage and disengage said contact portions and contacts,l means limitingl closing movement of said blade 4member so that at the closed position o! said switch said contact portions engage onlyv the portions of said contacts adjacent the edges thereof facing the path of opening movement of said blade so as to be entirely engaged or dis- .5. In a device of the character described, an open substantially rectangular supportingrame, insulating means carrying a' contact in the frame ,and supported on one side of said frame, other 5 insulating means carrying a switch blade, said other insulating means pivotally mounted in said frame adjacent the opposite side thereof, a second contact supported at a point spaced from the plane of said frame in a position such that said 10 blade member is movable through said frame into and out of bridging relation with respect to said contacts. A GORDON F. SAUERS.

engaged with respect to said contacts as the relliI s'ult of relatively slight movement ot said blade.