US2014272A

US2014272A - Switching means

Info

Publication number: US2014272A
Application number: US531342A
Authority: US
Inventors: Blomquist Ernst
Original assignee: Individual
Current assignee: Individual
Priority date: 1931-04-20
Filing date: 1931-04-20
Publication date: 1935-09-10
Anticipated expiration: 1952-09-10

Description

Sept. 10, 1935 E. BLOMQUIST 290149272 SWITCHING MEANS Filed Apr-i1 2o, 1931 a sheets-sheet 1 @mms- Sept. 10, 1935.

E. BLOMQUIST SWITCHING MEANS Filed April 20, 1951 8 Sheets-Sheet 2 4 JV B 757 7515 $50 &0

757 o 97 O O 75/ Sept. 10, 1935. `E, BLOMQUIST 2,014,272

SWITCHING MEANS Filed April 20, 195]. 8 Sheets-Sheet 3 E. BL'oMQUlsT Sept. 10, 1935.

SWITCHING MEANS Filed April 2o, 1951 8 Sheets-Sheet 4 QZ/J,

Sept. l0, 1935. E BLOMQUIST 2,014,272

SWITCHING MEANS Filed April 20, 1931 8 Sheets-Sheet 5 E. BLOMQUIST SWITGHING MEANS Sept. 10, 1935.

Filed April 20, 1951 8 Sheets-Sheet 6 Sept. 10, 1935. E. BLOMQUIST 2,014,272

SWITCHING MEANS Filed April 20, 1931 8 Sheets-Sheet 7 QQ fa d;

E. en .oMQLns-rA swToHING MEANS Sept. 10, 1935.

Filed April '20, 1931 8 Sheets-Sheet 8 Patented Sept. 10, 1935 UNITED STATES maar OFFIQE 11 Claims.

This application is a continuation in part of my Patent No. 1,908,815, granted May 16, 1933, and relates in general to switches and switching cabinets. y

In recent years, with the coming into use of higher and higher distribution and transmission voltages and the growing demand for electric service in small communities where electric service was hitherto unavailable, the matter of obtaining a compact and economical distribution center or substation has become a matter of great importance. The function of a distribution center is to receive electric power from a remote source, step or transform it to the Voltage suitable for local distribution, and provide suitable tapping connections or busses from which the feeder lines may extend.

High voltage transmission lines in this country generally transmit three phase power. rlhe voltage of the transmission line is stepped down to a suitable distribution voltage by means of three single phase transformers. A fourth transformer is provided as a spare, and suitable switching means are provided for connecting the spare transformer in circuit in lieu of any one of the three transformers that may have become defective or that may require inspection.

This invention relates more particularly to the switching means for substituting a spare transformer for one of the transformers in the main 'transformer bank, and it is one of the objects of the present invention to provide a switching cabinet for enclosing those switches. I provide a cabin-et having an oil bath for the switches on the high voltage side of the transformer bank, thus permitting the use of smaller and cheaper switches than would otherwise be necessary since switches of the type designed for outdoor service if in mersed in an oil bath may be use-d on voltages appreciably higher than that for which they were designed, without any sacrifice in the degree of safety provided.

The switches en the high tension side of the transformer bank are enclosed in an oil tank and the switches on the low tension side of the transformer tank are also enclosed in a tank but are not immersed in cil. rhe means for operating the switches extends outside of the respective tanks and .is fully enclosed adjacent each of the switches. In View of the fact that all of the switching equipment is enclosed, I have provided interlock arrangement to prevent the inadvertent operation of the wrong switch and also have prcvided an indicator for showing the position of the respective switches. The interlock between the transformer selector switches is so arranged that any faulty transformer can be replaced by a spare transformer by first turning the interlock indicator to the proper position to release the switches controlling the particular 5 faulty transformer to be replaced, which operation releases the switches on the high tension side and on the low tension side of the particular transformer. The released switches may then be pushed into the downward position which operalo tion automatically disconnects and grounds the windings of the faulty transformer and connects the spare transformer in its place. The interlock indicator will also serve to indicate which transformer is disconnected. The interlock is l5 so arranged that it is impossible to gain access to any of the switches until the circuit through the transformer bank has been opened at another point, thus rendering operations at the switches perfectly safe. The interlock not only prevents 2o operation at the switches but also prevents the touching of the switch handle of the transformer selector switches until the circuit through the transformers has been opened.

A cover is provided above each switch and to operate the switches the cover must be opened and the switches are then operable by means of an operating rod which is inserted through the open top. The interlock prevents opening the cover above any of the switches until the circuit 3o through the transformer bank has been opened at another point.

One of the novel features of this invention lies in the manner in which the high voltage power conductors are extended into the oil cabinet. 35 According to my invention, standard potheads are used, the potheads being mounted in an inverted position directly upon the oil cabinet. This provides a very simple and effective way for leading the conductors into the cabinet, avoiding the so use of porcelain bushings such as are used in standard practice upon high voltage transformers.

The attainment of the above and further objects of the present invention will be apparent le from the following specification taken in conjunction with the accompanying drawings forming a part thereof:

In the drawings:

Figure l is a simple diagram of the connec- 50 tions at the switching center;

Figure 2 is a sectional view through the high Voltage oil switching cabinet, said View being taken along the line 2 2 of Figure 5 with the bulk of the interlocking mechanism omitted; 55

Figure 3 is a plan view of the switching cabinet of Figure 2, with the cover removed;

Figure 4 is a sectional View taken along the line 4 4 of Figure 2;

Figure 5 is a top View of the switching cabinet with the sleet cover removed, said view being taken along the line 5 5 of Figure 6;

Figure 6 is a sectional View taken along the line 6 6 of Figure 5;

Figure '7 is an enlarged fragmentary top view taken along the line 'I I of Figure 6;

Figure 8 is a sectional View taken along the line 8 8 of Figure 7;

Figure 9 is an enlarged View of the interlocking control lever shown in Figures 5 and 6;

Figure 10 is a sectional view through a modified form of switching cabinet such as is adapted for use on the low voltage side of the transformer bank, said View being taken along the line I0 I 0 of Figure 11;

Figure 11 is a sectional view taken along the line Il II of Figure 10;

Figure 12 is a longitudinal sectional View showing a modified form of mechanism for operating the bayonet switches within the switching cabinet, said view being taken along the line I2 I2 of Figure 14;

Figure 13 is a sectional View taken at right angles to that of Figure 12, said view being taken along the line I3 I3 of Figure 14;

Figure 14 is a sectional View taken along the line I4 I4 of Figure 12; and

Figure l5 is a fragmentary enlarged View of the indicating mechanism provided for the mechanism of Figures 12 to 14.

In order to facilitate an understanding of the arrangement of the parts Within the switch and fuse cabinet and the function of the various parts, reference may be had first, to Figure 1, showing in diagrammatic form a circuit diagram of the connections at the distribution center. An incoming line I, which is assumed to be three phase and 33,000 volts, extends through the air brake switches 2 to the fuse and switching cabinet 3. It is, of course, understood that the incoming line may be of any other number of phases or at any other voltage. The line conductors extend through the fuses Il mount-ed within the oil cabinet 3, thence to the six bayonet type switches indicated at 5 to I0 inclusive. There are two switches provided for each of the A, B, and C phase transformers as indicated in Figure l. The shaded part of each of the switches 5 to I0 inclusive indicates the insulating portion of the switch whereas the unsha-:led part indicates the conducting portion. The circuit from one of the line phase conductors extends from the fuse 4 to the terminal II of the switch 5, thence through the conducting segment i2 of that switch to the terminal I3 which is connected to one pole of the A phase transformer. A connection from the same fuse 4 extends to the terminal I4 of the switch 6 and by way of the conducting portion of the switch 5 to the terminal I5 which extends to one pole of the B phase transformer.

Likewise, other line conductors I extend through the other switches to the B and C phase transformers. The upper conducting portion i8 of each of the disconnect switches 5 to I 0 inclusive is connected to the grounded conductor 20. The lowermost contact 22 oi the alternate switches 5, I and 9 are connected to one pole of the spare transformer and the similar lowermost contact 23 of the alternate switches 6, 8 and l0 are connected to the opposite pole of the spare transformer. When the switches are in the position indicated, the A, B and C phase transformers are connected in circuit with the high voltage line I and the spare transformer is disconnected from the circuit. 5

The conductors from the secondary or low voltage side of the transformer bank extend to the switching cabinet 28. Within the cabinet 28 are mounted three bayonet type disconnect switches 35, 36 and 3l of a somewhat similar con 1o struction to the switches mounted in the cabinet 3. The conductors from the A phase transformer extend to the upper terminal clip A0 and the lower conducting segment 4I, respectively, of the disconnect switch 35. One of the three outgoing 15 feeder conductors 43 is connected to the terminal clip 44 of the A phase switch 35. The other two outgoing feeder conductors are connected to the corresponding clip of the other two switches 36 and 3l. The clips 45 of the three switches are L0 connected together and extend to one pole on the secondary side of the spare transformer S and the other side of the spare transformer is connected to the conducting portions i5 of each of the

switches

35, 36 and 3l.

With the switches in the position shown, the A, i3 and C phase transformers are connected circuit. To replace one of those transformers cy a transformer, it is necessary to depress the ccrrcfprinding switcheson the high voltage side of the transformer bank and the one correlng switch on the low voltage side, If it ed 'to replace the A phase transfer, 1' by the spare S, thD switches 5 and l0 within the ching cabinet l depressed as is also the .'55

'.zthin the cabinet 20. The depression of the switch 5 causes the conducting section i2 'dge the contacts il and 22 thus me pole of the spare trantioriner to ssion line, and it connects the ccnwe: .fon i8, which grounded, to the terf, thus grounding one side of the A -..as-e transformer. In like manner 'the disconnect switch l0 connects the other side of the spare transformer to the transmission line and I grounds the other terminal of A plie former. C-n the secondary side of the trans; er bank, the depression of the disconnect switch disconnects the terminal fili from the terminal i3 which is connected to the neutral of the sy.. 551i tem and instead connects the segment thereto,

ment being connected previously state:

to one ...ido of secondary of the spare transformez'.

usly bridged the terminals il." es the terminals M and ifi t'n 'c the opposite pole of the spare tran a outgoing feeder conductor which conne :lcd to the terminal :le and at the of time disconnecting the opposite s'de of t-e scf-- ondary of the A phase transformer from the ci cuit.

Reference may now be had to Figures 3, 5,

0 showing the construction of the s itch c.; and fuse cabinet 3 and the switches and int-erlocking mechanism therefor. The switching cabinet 3 is made ci steel sheet and is mounted upon beams The sheet steel cabinet or suitably reinmced at the corners l' means of angle beams E6. Two horizontal ci bars 'il and 'l2 (Figure 4t) mounted wit" the oil tank and support the panels "I3, i3 and 13 upon which the switch contacts mounted. A lower bracket and an upper bracket l5 (Figeach ure 2 are secured to the rear side of the panel section i3 and support an insulator 'il supporting a fuse holder 'i8.

The fuse of Figure l is mounted within the fuse helder '58. Brackets similar to 'it and l5 are mounted at the rear of each of the panels 'i3' and supporting insulators lll for the other two phases of the system. The fuse holder' may be of any preferred construction and since does not, per se, forni a part of the present invention the precise construction thereof has not been illustrated. For a -further ecription ci? the fuse holder reference may be had to my Patent No. l,3 7,369, issued November 8, 1932.

The lead--in-conductors from the power line extend into the oil switching tank through inverted potheads as previously stated. The pothead @Se for of the phase conductors is indicated in Figure 2. The pothead is secured to the upper portion of the oil tank by inea-ns of suitable extending through iianges indicated at IThe p n 82 of the pothead is the portion which in the usual use of potheads eX- tends in an upward direction. The lead covered cable extends into the potheads and at the lower end a conne tion is inade to the copper cv duct-cr wi'- the cable and a flexible lead indicated at @E is secured thereto. The sheet metal cas-e or cabinet is provided with an opening @to above each of the fuse holders i8 for permitting the insertion or removal of the fuses with or without the fuse holders 1S. A pipe section lll is nioiuited upon the top of the cabinet adjacent of the openings and there is` provided a hinged cover Q2 hinged at 53 for permitting access to the fuse.

he circuit extends from the conductor 85 to a contact clip which is secured thereto and which is clipped on to the fuse holder for establishing a through the fuse within the fuse hole: clip is indicated at 8o and has a threaded shank integrally secured thereto. may be withdrawn from the fuse holder by inca-ns of "he handle 83 within the pipe sect' in Si, said handle being at the end of an insuiator which has fuse gripping means at the op- L e end th eci. When the fuse has been removed, *be s"- l may be reached through the eans of a rod or other tool havopening e a nut at the end thereof for threading on to is then pulled out of enwith the fuse helder i8 to permit withdrawal of the fuse holder. The clip cannot be tie sha i The clip gagnes/1Q it is necessary to use tools in rather than the bare hand, be-

et lled with insulating oil which during cold ...inter weather reaches such a low te .iperature as to preclude any possibility of g the bare hand for manipulating the clip The linger 39 is provided in order to nx the location of the clip when the same is being sought by the tool used for placing it on the fuse holder.

A conductor tot extends from the lower terminal of the fuse holder l through the hollow insulator lili to the terminal clip il of the A phase switch ti. A conductor to2 comprising a copper bar connects the terininal il with t'- e terminal lil of the B phase switch The conducting section l2 of the switch E is adapted to electrically connect the terminal i l with the terminal it when the switch is in the position shown in 2 or to connect the terminal l! with the terminal 752 when the switch blade is depressed.

The switch terminal clip lit is mounted on an insulator which is secured to the panel section l-l, and the lower terminal clip 222 of the switch 5 is supported by an insulator itil which mounted upon the panel i3 at the lower end thereof. A flexible conductor it? connects the upper terminal clip lil to the lower terminal m8 of a pothead i539. The pothead EE@ is of standard construction and, like the pothead E2, it is mounted in an inverted position. A lead sheathed cable ilo extends outward from the pothead to termi al of the A phase transformer thus establishing an electrical connection between the terminal clip iii and the A phase transformer.

The switch 5 comprises a strip of rnicarta or other suitable insulating material H5 which eX- tends the entire length of the switch. Contact ly less than the ull extent of travel o1" the switch @fill e blade in the downward direction when the l beis pushed so that the contact strips llt tween the Contact li and the contact 22.

When the switch 5 is depressed so as to establish a circuit etween the contacts il and the bare insulation lili lies between the contacts i and i3, and the Contact strips l it are in engagement with the contacts i3 and 22. A flexible grounded conductor connected to the con-- tact strips l l@ which Contact strips extend to t ie top oi"- the roicarta insulation H5. The flexible conductor i2@ connects the copper strips lit with a grounded copper conductor lili which extends through the switch cabinet. The car llt; with th extends upward through an opening in the top of the casing and has a srnall hole formed therein for manipulating the switch, the upper end being enclosed in a pipe 25 provided with a cover lill hinged at To manipulate the switch the cover l'i is swung to the open position and a hook at the end oi a suitable switch operating stick is inserted to the opening and is manipulated to force the switch downward or upward as the case may be.

The contacts it, may be of any ciesired construction and preferably consist oi two spring pressed jaws indlcat .i more particularly at ist Figure Ll. to slide between the spring pressed. contact jaws it@ and a suitable hooi; or bale iti is provided at each oi the pairs ci jaws for retaining the blade between the jaws.

When the switch 5 is depressed, a connection s ie strips H8 on the opposite sides thereoi- The switch blade Cil is established from the terminal I I, which is connected to the incoming line, to the terminal 22, which, as will be pointed out hereafter, is connected to one side of the spare transformer. At the same time the contact portion I2 interrupts the connection between the contacts II and the Contact I3 and the grounded conducting portion IIS comes into engagement with the contacting portion I3 thereby grounding one side of the A Phase transformer.

The three incoming line conductors l for the three phases extend into the switching cabine through potheads such as the potheads Silla and extend through fuses on mcuntings i8 and I8 similar to the iuse mounting 'I8 shown in Figure 2 and then the B and C phase conductors extend to the switches 1 and 9 of a construction identical to the construction of the switch 5. The switch 6, which is opposite of the switch 5, has a flexible conductor ex'ending from its upper terminal clip iii establishing a connection to a conductor which extends into t -e switch house through an inverted po'thead E35 from which a connection is established to one pole of the B phase transformer.

As may be seen from Fig. 3, the switches 5, 'i and SI which control the connections to one side of the A, B and C phase transformers, respectively, are mounted on one side of the switching cabinet and the switches 6, 8 and lil, which are mounted on the other side oi the switching cabinet, control the connections from the other terminals of the B, C and A phase transformers. The terminals I! and I4 of the switches and l5 are connected together by a copper bar H12 and the corresponding terminals ci the switches 'I and 8 are connected together by a similar bar IDR whereas the corresponding conductors of the switches 9 and ID are connected together by a bar |02.

The lower terminals 22 of each of the switches 5, 'l and 9 are connected together by a strip of copper I 40 which is connected by means of a ilexible conductor I4I to the lower end oi the inverted pothead |42 from which a connection extends to one terminal on the high tension side of the spare transformer. In a like manner the lower terminals 23 of the three switches 6, 8 and IU are connected by means o a flexible conductor to an inverted pothcad as indicated at |43 in Fig. 3, from which pothead a conductor extends to the other terminal on the high tension side of the spare transformer.

It may thus be seen that ii the two switches and It) are depressed that the high tension side of the A phase transformer will be disconnected frorn the incoming line and will instead be grounded, whereas the two terminals on the high side of the spare transformer will be connected in place of the A transformer. In a like manner ii the two switches t and 'l are depressed instead of the switches 5 and IG, the B phase transformer will be disconnected and the spare will be connected in its place. in a like manner the switches 8 and 9 control the establishment of connection. for substituting' the spare transformer for the C phase transformer. The switches 5 to I!) are mechanically interlocked so as to prevent manipulation of non-corresponding switches at the same time thereby preventing any attempted substitution of the spare transformer for more than one of the three transformers. The interlocking arrangement will be fully described the description proceeds.

The switches 6, 8 and IB are of a construction identical to the switches 5, 'l and 9 and the switch contacts for those switches are mounted on suitable panels 145 similar to the panel The panels 'i3 and M5 are suitably braced by braces ME and I4?. 5

The switching tank is lled with a high grade insulating oil or other suitable insulating liquid to a level above the top of the fuse holder i8.

An explosion valve ist is provided in the top portion of the switching cabinet, said valve comprising a pipe of suitable diameter provided with a. cover i539 hinged at itil and intained closed by a spring i? which is adjusted to a suitable tension to maintain the cover closed until the pressure within the oil tank exceeds a certain limit whereupon the cover is forced open against the action of the spring. A. une mesh wire screen E55 is provided above the opening Miti to prevent the dropping of foreign material into the oil tank. 2()

A description will now be given of the interlocking mechanism for interlocking the various selector switches ti to iti inclusive amongst themselves and with the operating mechanism for 0perating the pole top switches As previously 2 stated each of the disconnect switches is operby irst opening the cover ifl'i (Fig. 2) then manipulating the switch by means oi a suitable switch operating rod. As will be presently pointed out there are two forms of locking mechanism provided; one ferm of locking mechprevents the opening of the covers such as i2] when the pole top switch is closed and thereby prevents the manipulation ci the selector switches and a second interlock is provided for the inadvertent manipulation oi the wrong disconnect switches. A description will first be given of the apparatus for locking the covers i2? to prevent inadvertent manipulation of the suf'itches when the pole top switches F. are 40 closed, and :for this purpose reierenc s may be had to Figure 5.

As is well known in the art, the disconnect switches 3 are mounted on top oi a supportin tower or similar supporting structure and are adapted to be operated in unison by suitable operating mechanism located at or near the bottorn of the switch supporting structure, by of a rod extending vertically from the operating mechanism to the switches 2. A rotatable pipo 5() t2 (Figure 5) which controls the locking of 'the covers ifi? extends from the switching cabinet to the operating mechanism or to one of the levers that control the operation of the gang disconnect switches 2 of Figure l. A clevis is suitably 55 secured to the end of pipe Il and mechanical connections are made between this clevis and i, mechanism that controls the switches i! so that when the switches are operated to their open position the rotatable pipe is rotated to the position shown in Figure 6, whereas when the mechanism is actuated to close the switches the pipe 52 is rotated through QG from the position shown in Figure 5. The pipe S2 extends to the selector switching cabinet and is sup rted in suite-.bie (is inber i726 (Figure 5) and another similar brackt IGi secured to the foremost pipe section. Each cover I2? is mounted on the pipe section il? by means oi a pair of ears its formed integrally therewith and through which. the pipe E52 extends. pipe freely rotatable with respect to the covers. Each cover fi is adaptenl to be allv swung into po. .on alcove the close the saine, a pair of wing nuts being suitably bearing bracket M35 secured to the end pipe CII secured to th pipe section and provided in order to securely hold the cover in position. The wing nuts are indicated at It and Il@ in Figure 7. Locking lugs ill are rigidly secured to the pipe section S2 adjacent the respective covers l2l and, when the pipe section is rotated through an angle of 90 in a clockwise direction from the position shown in P-ligure the locking lugs assume a povent op g of the covers.

When the pole top switch 2 is moved to the open position, the shaft 62 is rotated to bring the locking lugs into position shown in Figure il, thereby permitting the opening of the covers iili as desired. When the pole top switch is in the switch closed position, the shaft 62 is moved through an angle of approximately 99 thus bringing the locking lugs lli immediately above the covers lZl and preventing the opening of the covers; and thereby preventing manipulation of the selector switch. rhe covers l2ll for the three switches 5, l' and il are mounted upon the locking shaft and the covers l'll of a construction identical to the covers l2? are in a like manner mounted upon a locking shaft Vit similar to the shaft The locking shaft il@ has a crank arm El'i rigidly secured thereto and is connected to the shaft t2 by means of a link Vit and a crank ile which is rigidly secured to the locking shaft The covers (Figures 2 and 5) above the fuses are hinged to freely swing about a shaft by means ci two members i3! formed integrally therewith and through which the shaft extends, in the same manner as covers iill and are mounted to freely swing about their respective shafts. Locking lugs E83 are rigidly secured to the shaft 93 adjacent each of the covers and are adapted to be swung over` the covers 92 to prevent opening of the covers, all in the same manner as do the locking lugs lll previously described.

A crank arm 132 is rigidly secured to the shaft E3 is connected to the crank V59 mounted upon the shaft t2 by means of a rod |86. When the shaft S2 is swung to the position corresponding to the closed position of the pole top switch, the locking lugs it?. are above the covers e2 and prevent opening of those covers.

A description will now be given of the interlock provided between the various selector switches 5 to it for preventing the manipulation of more than one set of selector switches at a time. An interlocking lever 2de extends through the three pipe sections |26 housing the upper po ns of the switches 5, 'l and 9, suitable open- Tse 'Der portion of the blades 5, 'l and 9 is prevI with a notch through which the locking leves. the notch in the blade 5 being indicated at in Figure 8. When the locking l is out of the position shown in Figures l and 8 the switch blade 5 cannot be depressed because the locking lever is within the notch n the switch tl.

lf the lever 2% is shifted in a manner to be presently more fully described, by an amount suiiicient to bring the notch Zitti into the space occupied by the notch 295 of the blade 5, it will be possible to depress the blade 5, said blade moving downward within the notch 26%. When this has been done it is of course apparent that the blades 2d?) will retain the locking lever 260 in position preventing further movement of the locking lever until the blade has been restored to the position shown in Figure 8. A notch 26T similar to the notch 2li@ is provided in the locking lever adjacent the switch l, the two notches and 2d? being spaced from the respective switches by unequal amounts so that one only of the two notches is in register with a switch blade at a time. When the notch 2% is under the switch blade Ei, the notch itil is spaced from the blade l and the blade 'i cannot be depressed, whereas if the locking lever is moved a slight additional distance th n the notch 2in will come immediately into posi on opposite the switch blade l thereby permitting manipulation of the switch l', whereas the notch Eilii will have moved beyond the switch blade E5 and the switch blade 5 is again held against motion. If the locking member 2de is moved still further then the notch 2c? will advance beyond the switch l and that switch will also be locked against motion, whereas the end of the lever 2m, that is adjacent the switch d, will ride past the switch il thereby permitting manipulation of the switch 9.

In this manner, as is apparent, only one of the three switches il, 'i and Si can be manipulated at a time and when one of the switches is operated into the downward position the other two switches are held locked and likewise the interlock mechanism is also locked in its position.

A crank arm t2@ pivoted at 22E is connected to the interlocking member 20@ by means of a link 222 so that upon turning the crank arm 22e the locking lever aldil is shifted. An operating handle it is welded to the bell crank 226 or may be otherwise rigidly secured thereto so that when the operating handle is actuated the bell crank 22d is turned with the result that the locking lever Eil@ is manipulated. A hand gripping member 225 is provided for actuating the handle 225.

An arcuate shaped plate 228 having four notches 22e therein is provided for accurately determining the position of the interlocking lever from the position of the handle 225. A V shaped projection 23d is provided on the under side of the lever 225, said projections riding upon the arcuate shaped member 223. When the projecting member 23d rests in one of the notches 229, a corresponding notch in the lever 2d@ is opposite one of the switch blades, and there is provided a plate having the letters A, B and C marked thereon, the markings and the notches 22d being so spaced as to indicate which one of the switches E, l or fl is unlocked when the lever is in a position opposite the respective notches.

The arcuate plate 228 is provided with an additional notch i3d and the name plate is provided with a letter O opposite ie position of the handle when the handle rests at the notch This indicates that none of the selector disconnect switches 5, 'l or il can be operated.

The switches ii, t and ii) are provided with an interlocking lever similar to the lever Zilli, said lever being operated by a bell crank 23S connected to the bell crank 22@ by means of a rod 'iil. When the handle portion 225 is shifted to a position opposite the indicating letter A, the notch 29e in the lever 2cd comes opposite the switch Ei, whereas a corresponding notch in the lever 235 comes opposite the switch i3. Under these conditions the switches 5 and I3 may be operated, whereas

switches

1, 9, 6 and 8 are held in a locked position. When the handle 225 is in the B position, the switches 6 and 'l ar` released whereas the other switches are held locked, and when the switch handle is in the C position, the switches 8 and 9 are released whereas the other switches are held locked.

As previously stated in connection with Figure i, the selector disconnect switches on the low tension side of the transformer bank are housed in a cabinet 23. The cabinet 28 as well as the switches therein are of a construction such as will be more fully set forth as the description proceeds. The cabinet 28 is located adjacent the cabinet 3 and the switches therein are provided With interlocks identical with the interlocks described in connection with the switches on the high tension side of the transformer bank. The covers 243, of a construction substantially similar to the covers 92, 55B, and H5, are mounted upon a rotatable shaft 2M similar to the shaft 62, said shaft being provided with locking 242 similar to the locking lugs lll for preventing the opening of the covers 24D. A crank 245 is secured to the shaft 24! and said shaft conu nected by means of a connecting rod 245 to the crank |11, and by means of a connecting' rod H8 to the crank Il.. as shown more particularly in Figures 5 and 6. When the pole top switch 2 is open, the lugs 242 are in a position to permit the opening of the covers 243, whereas when the pole top switch 2 is closed, the lugs 242 are immediately above the covers 249 and prevent th-e oponing of the covers, all in the same manner was previously described in connection with the covers on the high tension side of the switching cabinet.

The

switches

35, 36 and 3'! are interlocked by means of an interlocking member 253 of a construction similar to the lock member 230 and provided with notches in a similar manner. The locking lever 250 is connected to a bell crank 252, pivoted at 252, by means of a link 253 and a rod 254. A pipe section 255 encloses the rod 254, suitable packing being provided for preventing the escape of any lubricant that is introduced into the member 255 to reduce the friction therein. Similar rods and packings are provided for the members that operate the locking levers 233 and 235 on the high tension side of the switching cabinet. The notches in the locking lever 255 for locking and releasing the

switches

35, 36 and 3l' are spaced similarly to the spacing of the notches in the lever 20D and when the operating handle 225 is in the O position all three of the switches are locked whereas when the handle 225 is shifted to the A position the switch 35 is released; when the handle 225 shifted to the B position the switch 36 is released; and in the C position the switch 31 is released.

To replace any phase transformer with the spare it is merely necessary to set the interlock lever handle 225 on the position indicating the transformer to be replaced (A, B or C) and then to push the three switches (two on the high tension side and one on the low tension side) marked correspondingly into the down position.

The switches are of course pushed down by means of a switch hook.

To change back from the spare transformer to the corresponding phase transformer it is merely necessary to note the position of the interlock control lever 225 and then pull up the three switches with the corresponding markings into the upper position and thereafter the interlock control lever 225 to the O position.

An interlock is provided for preventing the manipulation of the lever 225 from the O posiM tion to either the A, B or C position when the pole top switch is closed. A forked crank 23D is secured to the locking shaft .32 and controls the movement of a locking in Ztl, The locking pin 2.5i is arranged to ride freely in a groove 2532 in the crank 2.6i] and is guided in

suitable guide

263 and 254 secured to the pipe section E2G may be seen in Fig. 6. When pole top switch is in the open position, the crank 230 is in the position shown in Fig. 6 and the pin liii is in its uppermost position. When the pole top switch is operated to the closed position the crank 2533 is rotated in a clockwise direction as is seen in Fig. G, thus allowing the pin to drop downward into the path of movement of a lever 286 integral with the lever arm 225. When the lever handle 225 is in the O position, the portion 23u is located to the right of the pin EGl. The position of the arm as seen in Fig. 9 is the position occupied when the arm 22" is in the A position, the dotted line position of the meinber and 225 being the position ci the interlock control lever.

it is thus apparent that when the arm 233 is in the position shown in dotted lines in llig. El which is the O position of the interlock, and when the pole top switch is closed the pin ZBI is dropped downward into the path of movement of the arm 263 and the arm cannot be moved from the O position to the A, B or C positions until 'the pole top switch is opened thereby rotating the crank 233 and raising the pin 226i out of the path of travel of the arm This is ci in poi-tance for otherwise it might be possible to manipulate the handle 225 to the A, B or C position and leave it there without operating the cor responding switches. If the pole top switch were kept closed and service continued with one of the phase switches unlocked, it might happen that after a long period of time the switch that is unlocked would drift downward. The selector switches are not designed to open the circuit when there is current flowing therethrough and if the selector switch that was inadvertently unlocked were to drop downward a dangerous and very destructive arc might be generated. The above describes interlocking arrangement prevents such an occurrence.

A description will now be given of the selector switches on the low tension side of the transformer bank and for this purpose reference may be had to Figures 10 and 1l.

The switch cabinet 28 is constructed of sheet steel and is suitably supported by I beams mi) in any desired manner. Panels itil, 232 and 253, upon which the

switches

35, 36 and are mounted, are bolted or otherwise rigidly secured to a top angle beam i265 and to a bottom angle beam 255. The three panels are identical as are likewise the switches supported thereon. The switches 35, 33 and 3'! are of `the bayonet plunger type and are operated by an upward and downward movement of the switch blade. The blade proper consists of a strip of suitable insulating material of prerequisite mechanical strength and electrical insulating qualities needed, and in the present case comprises a strip of micarta insulation although any other suitable insulating material may be used. The micarta insulation is indicated at 265 and comprises a strip of a length Cll extending the full length of the switch blade. Micarta insulation comprises suitable strip canvas impregnated with a phenol condensation product such as bakelite. Contact strips of copper or other suitable conducting materials are secured to the strip or insulating material 255 along the edges thereof at the desired points where contact is to be niade between the various contacts as will be presently set forth. The switch is adapted to slide between a number of sets of contact indicated at El?, Ell, Els and 273.

The contacts comprise a pair of jaws of copper or other suitable conducting material which are spring pressed against the switch blade so as to make good electrical contact therewith. A bail E'l between the jaws and similar Aballs between the jaws of the other sets of the contacts are provided for preventing the switch blade 2&5 from shifting out oi the jaws and at the saine time maintaining the jaws together. The ccntacts 2@ are mounted upon an insulator l'li secured to the panel 526i. The other c ntacts 27H, 2132 and 233 are mounted upon similar insulators similarly secured to t .e panel. Two conductors 2li and 21's extend from the secondary or low tension side of the i -phase transe former to the switch cabinet 28. The conduc tors 2li" and t'll extend to the switching cabinet 2S in a conduit El The conductors on the B C phase transformers likewise extend to the cabinet in conduits 2d@ and 253i respectively, whereas the conductors from the secondary or low tension side of the spare transfer to the switch cabinet in a conduit 1 The con ductors Elu extend through a clamp insulator to a terminal clip 2st mounted on an insulator 253? at the lowerinost end of the panel Edi. A ilexible conductor EBS connects the terminal on the insulator 2SC-l with a pair of contact strips 2% secured to the opposite sides of the insul section of the switch blade The co itact stri* s teil ride between the contacts Sie upon the insulator 295 when the switch 35i is in its uppermost position. When the switch is .moved downward the contacts u disenfgage with the contacts 233. The lowerinost cont cts 3243 of each or three switches "n 3l are connected together by a bar of copper or other suitable conducting' material and constitute the neutral ci the system. rThe bar has the neutral ground conductor connecte". thereto and liiewise has a conductor Beft, which is the neutral of the system, connected thereto, said conductor 2de extending outward wi n the outg ng phase leads as will be more fully plained as the description proceeds. A L ot copper strips are secured to the opposite side of the inicarta insulation 25: of the switch til at a point between the contacts and said copper strips bridging those contacts when the switch is in the position as shown in lO and ll. A conductor dill, which is one ci the outgoing phase conductors, is connected to a terminal clip 362 which is permanently secured to the contact ll. When the switch 35 is in the position shown in the drawings a circuit is established from one terminal of the low tension side of the ../-\.-phase transformer through the conductor 2li and contacts 21u, thence by way of the conducting strips dit@ to the contacts till to the outgoing phase lead The conductor which is connected to the other terminal of the low tension side oi the A phase transormer, is connected to the system neutral 292 by means of the exible lead 236,

contact strips 29@ and contacts i'lt. Similar connections are established from terminals the B and C phase transformers. going leads l, 3525i and ist as well as t 29d extend from the switching ca conduit @it to the various oi distribu A similar conduit @il is provided to carry a set of conductors connected in parallel with the con-l ductors within the conduit 3 l t should the capacity ci the distribution center increase to such a as to necessitate the replacement ci the trans-- former bank by another bank of larger capacity. The strip ci insulation or switch extends u ward through the top o the cabii et E8 into a pipe 'S l and adjacent the top thereof withM in the pipe it is provided with means for per mitting an operating hook to the rihis means may comprise hole such as the hole in the switch 5 shown in Fig. To substitute the spare transformer for A phase transformer, the cover of the pipe is opened, the pole top switch (Fig. 1) having been preu Viously opened to permit the opening of the cover 'ic-ii as has been previously pointed out, and switch 35 is pushed downward by means of a suitable operating hook, the interlock r W.ianisni previously described having been set to the A position. W hen this is done the upper insulating portion of the switch 35 moves between the contacts illu, thus disconnecting the conductor "ill from the circuit.

At the time the conductor strips downwardly to bridge the gap between tacts 2li and El?.

the conone terminal of the spare transiormer. A ductor 33@ extending from tl e other termine the low tension side of the spare transiorr is connected to the copper bar wir-.ich conn nected to the contact strips 325i by means of flexible conductors or leads Similar e conductors connect the copper bar 331 with the contacts corresponding to the contacts switches 3d and 3l. When the switch. pressed, the contacts extend into engagement with the contacts H3 thereby establishing a connection between the ba 33t, which is connected to one terminal of the spare transformer, and the bar 292 which is connected to the conduct constituting the neutral of the outgoing distribution line.

It is thus apparent that by depressing the switch 35 the A phase transformer is disconnected from the circuit and the spare trai oriner is connected in its place. In a like ma r a dcpression of the switc 3S or til will stitute Uh spare transformer for the B or C transformers. The switches being interlociced by mechanism previously described in connection with Figure 5, it is apparent that it impossible for an operator to actuate more thai: three switches at a time. The copper pa t mounted to the side walls of cabinet, being secured place by means or" infil) sulators indicated at 3M and 342 As may be seen from Figur s hoods are provided for protect ing mechanism at the top of th from ice and sleet accumulating and interfering with or preventing the operation o the interlocking mechanism. Each or ee hoods con'iprises mereh7 a sheet met secured above the interlocking inechani .n sleet hood covers the locking mechant m for the covers 92 above the fuses in Ahe high voltage switching cabinet, whereas the sleet hood 35i covers the switch locking mechanism on hi .i voltage switching cabinet. The sleet hood covers the interlocking mechanism on the low voltage switching cabinet. Each or" the sleet hoods is provided with a hinged cover indicated at 352', 3M and for permitting access to the covers 52, ill, il and 24.

A hinged door (not shown) is provided at the front of the sleet hood Gili for permitting access within the elect hood to operate the interlock actuating arm 225. The connecting rods, such as the rod lili] and 245 between the respective slect hoods, are covered inverted channel shaped troughs i'or preventing the formation of ice and sleet upon the connecting members. To manipulate the switches or the high tension fuses, it is of course necessary to first open the covers on the respective sleet hoods.

As previously stated, the selector switches within the high voltage cabinet 3 and those within the low voltage cabinet 28 are pulled up or pushed down from one position to another by or" a switch operating stick. In very large installations where the switches are of appreciable size and the contact pressure between the contacts and the switch blades is appreciable the force required for directly operating these switches may become quite large. Since the switches are manually operted it becomes necessary to provide means for reducing the amount of effort necessary to operate the switches. In Figures i2, .1.3, and .la I have shown an arrangement for facilitating the operation of such switches, said means comprising a worm drive for moving the switches up or down. upper end of the switch 5 is provided with a screw threaded shank il upon which is threaded a nut if'ii. The nut is rotatable with respect to the shank and is held against downward movement by a iJ-shaped strap 492 which secured to the pipe section I in any desirable manner, as by means of sets ci bolts 494. The nut lili is held against upward movement by means ci Li-sha ed strap M5 which is suitably secured to the strap U2 in any desired manner, by means crews fill?. It is thus apparent that if the nut is rotated it will impart longit nal motion to the shank dill) since the nut itself held against upward or downward movement. It is oi course to be understood that the nut is freely rotatable between the straps 452 and lll.

A sleeve (lill is welded or otherwise suitably secured to the nut z'ii, said sleeve being free of the shank fili@ iree of the strap 6%. The sleeve extends upwa oy `iro-in the nut to adjacent the open top ci the pipe .section and is guided adjacent its upper end by means of an inverted U-shaped strap lil that i secured to the strap 4B@ by means of screws 4t2. The sleeve or pipe section 4 l reeniorc-d its outer end by means of a plug M5. The outer end of the sleeve MU is adapted to receive the end of a crank whereby the sleeve is turned and. to facilitate this action,

in Figure l0. 5 and 6,

cfs

a slot M6 is provided in the plug and in the end of the sleeve, said slot receiving the end of a pin in the crank nier-ober so that when the crank is turned it will turn the sleeve. Rotation ci thc sleeve produces a rotation of the nut 110| and a corresponding longitudinal movement of the shank lill and the switch blade When the switcl- E is provide-d with operating mechanism such above described it is necessary to provide means adjacent the top of the pipe section iii for indicating 'to an operator the position of the switch. I have provided such indicating means. A square rod flll which has been given a helical twist is secured to the blade 5 in any desirable manner, by means oi' a bracket fil@- whicE-:i is bolted to the switch blade. The rod ext ods into a sleeve B2i through a square hole in a plug i522 which is secured to the lower oi the slee' e The sleeve 112i is supported at if which rigidly secured to the pipe section 25, the sleeve b ing provided at its upper end with a flange which r on the bracket 424 and has an indicating p -nter 1125 formed thereon. The flange is r'gid with the sleeve d2! and the entire unit is free to rotate with reference to the bracket 'llil. A. stop member 423, secured to the top of the bracket lll revents upward Inoveinent oi' the sleeve .'ll. As the switch 5 moves downward the rod 52d is drawn downward therewith and slides through the square opening in the plug f' E that is secured to the lower end of the sleeve d i. Since the r d 42d has a helical twist A-ie rot lil imparts a rotative move- .-.leevey the extent ci movement being .-y .L e pitch oi' the helical twist t of downward movement of the blade 5. .e is twisted to the extent of approximately three-quarters of a turn for its entire length so that for the complete movement of the switch blade 5 the sleeve iii will be turned to an stent somewhat than three-quarters of one revolution. It is, however, to be understood that the rod f'llil may be twisted to a greater or lesser extent ii desired. When the pointer is in the position shown in Figure .l5 it indicates that the corresponding phase transformer is connected in circuit and to this extent the connections are indicated by the word Phase marked upon the bracket In a like manner, when the pointer has been turned hrough three-quarters of a revolution, indicating the opposite position of the switch, it will opposite the word Spare which is marked on the bracket 42:1.

In compliance with the requirements of the patent statutes, I have herein shown and described a .few preferred embodiments of my inveen. It is, however, to be understood that invention is not limited to the precise constructions herein set forth, the same being shown merely for illustrative purposes.

What I consider new and desire to secure by Letters Patent is:

l. In an electric system, a switching cabinet, a plurality of switches mounted in said cabinet. said cabinet having openings adjacent each of said switches, said switches having projections evtcnding through said ope. gs for operating said switches, tubes surrounding the respective openings and sealed to the cabinet and providing enclosures for the projections, closures for said tubes, hinge means for each oi said closures includinfT a common hinge shaft7 spaced locking means on said shaft for each of said closures. and

upper end by means of a bracket 424 common operating means for said locking means.

2. Apparatus for substituting one transformer winding for any one of a plurality of transformer windings that are connected in a circuit, said apparatus comprising a closed cabinet, a plurality of sets of vertically aligned contacts within the cabinet, switch blades for each set of contacts, each switch blade being vertically movable between two extreme positions establishing circuit Yconnections with different ones of the contacts,

each of the switch blades extending through the top of the cabinet, closures for the extended portions of the switch blades, covers hinged to the closures for permitting access to the blades, and means for preventing opening of said covers until the circuit through the transformer windings has been opened.

3. Apparatus for substituting one transformer winding for any one of a plurality of transformer windings that are connected in a circuit, said apparatus comprising a cabinet housing a plurality of individually operable switching members, there being at least one switching member for each winding replaceable by the rst mentioned winding, each switching member being movable from a normal position in which it maintains a circuit through one of the plurality of transformer windings to an alternate position in which it substitutes a connection to the rst mentioned transformer winding for a corresponding connection to one of the other transformers, means for preventing access to any of said switch members when the circuit through said windings is closed, and locking means for preventing movement of remaining switching members to their alternate positions while preselected switching members are in their alternate positions.

4. In a polyphase system wherein a set of single phase transformers is provided for transforming the system Voltage and a spare transformer is provided, switching means for substituting the spare transformer in circuit for any one of the other transformers, said switching means comprising a cabinet, and a plurality of individually operable switches in the cabinet, each of said switches including a v rtically movable blade and a plurality of vertically displaced contacts for each blade, certain of the contacts of all of the switches being associated with the spare transformer, other contacts of the respective switches being associated with the transformers of the .first mentioned set of single phase transformers, means carried by said cabinet preventing access to said switches when the circuit through said transformers is closed, and reciprocal locking means engaging said switches and operable to prevent movement of the switches of more than one phase into their vertically displaced positions at one time.

5. In a polyphase system having a set of single phase transformers for transforming the system voltage, and having a spare transformer, means for switching the spare transformer into the circuit in place of any one of the other transformers, comprising a switching cabinet, a plurality of aligned sets of contacts in said cabinet, switch blade members for each of said sets of contacts, said blade members having locking grooves therein, and common operating means including interlocking reciprocal latching bars engaging in said grooves and providing for selective operation of only certain of said members.

6. In a system of the class described, a switch cabinet, a plurality of laterally extending rows of spaced switch members therein having independent vertical movement for selectively engaging vertically aligned switch contacts, the ends of said members projecting through said cabinet, individual enclosure means carried by said cabinet for receiving said ends of said members, covers for said closure means, a hinge shaft for each of said rows of switch members, said covers being hinged on said shafts, and means on said shafts for preventing opening of said covers when the circuit through said switch members is energized.

'7 In a system of the class described, a plurality of rows of spaced switch members shiftable vertically for selective engagement with vertically aligned switch contacts, latching grooves in said switch members, laterally reciprocal locking bars for each row of switch members, each of said bars having unequally spaced recessed portions adapted to be selectively aligned with the grooves in said switch members to provide for movement of only preselected ones of said switch members at one time, and means for simultaneously actuating all of said bars.

8. In switching means for substituting a spare transformer for one of a plurality of single phase transformers employed in a polyphase system, a first switching cabinet, switches aligned in a plurality of rows in said cabinet for Vertical movement, a second switch cabinet spaced therefrom, a single row of corresponding switches therein, reciprocal latch bars for each of said ro-ws of switches, said switches and bars having cooperating interlocking engagement for preventing movement of said switches, means for actuating all of said latching bars in both of said cabinets simultaneously, and means providing for release of only a preselected switch in each of said rows from said interlocking engagement upon operation of said actuating means to place said selected switches in condition for transformer changing operation.

9. In switching means for substituting a spare transformer for one of a plurality of single phase transformers employed in a polyphase system, a first switching cabinet, switches aligned in a plurality of rows for vertical movement in said cabinet, a second switch cabinet, a single row of corresponding switches therein, reciprocal latching bars for each of said rows of switches, said switches and bars having cooperating interlocking engagement for preventing movement of said switches, means for actuating all of said latching bars simultaneously, and means providing for release of only a preselected switch in each of said rows of switches from interlocking engagement upon operation of said actuating means to place said selected switches in condition for transformer-changing operation, said actuating means being operable into a plurality of independent positions for Varying the switch selected in each row of switches in accordance with the transformer to be replaced.

l0. In switching means for substituting a spare transformer for one of a plurality of single phase transformers employed in apolyphase system, a rst switching cabinet, switches aligned in a plurality of rows for vertical movement in said cabinet, a second switch cabinet, a single row of corresponding switches therein, reciprocal latching bars for each of said rows of switches, said switches and bars having cooperating interlocking engagement for preventing movement of said switches, means for actuating all of said latching bars simultaneously, means providing for release of only a preselected switch in each of said rows of switches from said interlocking engagement upon operation of said actuating means, each of said switches having projecting ends, closure means for said ends carried by said cabinets, and means for preventing access to any of said switches through said closure means to operate the same when the circuit through said plurality of single phase transformers is closed.

11. Apparatus for substituting one transformer Winding for any one of a plurality of transformer windings that are connected in a circuit, said apparatus comprising a plurality of rows of vertically alined contacts, a plurality of switch blades for said rows of contacts, said blades being vertically movable between two extreme positions to establish circuit connections with diierent ones of said contacts, horizontally movable common locking shafts for the blade in each row of blades, and connecting means movable at right angles to said locking shafts and connected thereto for producing conjoint movement of said shafts.

ERNST BLOMQUIST.