US2360774A - Rotary disconnect switch - Google Patents

Description

oct. 17, 1944. l P, B HOYE 2,360,774

ROTARY DIscoNNEcT SWITCH Filed Aug. 1 0, 1942 v 5 sheets-sheet 1 Oct- 17, 1944. P. B. HOYE 2,360,774

ROTARY DISCONNECT SWITCH Filed Aug. l0 1942 5 Sheets-Sheet 2 fdef [70 e, Uy

Oct. 17, 1944.

P. B. HOYE ROTARY DISCONNECT SWITCH Filed Aug. 10 1942 5 Sheets-Sheet 3 llnigigggggmmmm Oct. 17, 1944. P. B. HOYE ROTARY DISCONECT SWITCH Filed Aug. 10, 1942 5 Sheets-Sheet 4 @ma rma/:fill: f

OCI. 17, 1944. R B' HOYE ROTARY DISCONNECT SWITCH Filed Aug. lO 1942 5 Sheets-Sheet 5 Patented Oct. 17, 19,44

ROTARY DISCONNECT SWITCH Poder B. Hoye, Maywood, Ill., assignor lto Electrical Engineers Equipment Co., Melrose Park, Ill., a corporation of Illinois Application August 10, 1942, Serial No. 454,235

' 5 claims. rc1. 20o- 6) The present invention relates generally to high voltage electric disconnect switches of the enclosed type, and more particularly to such enclosed disconnect switches wherein the circuit is opened or closed by rotary motion of the contacts. According to the preferred form of my invention the switch contacts, both stationary and movable, are housed in a vitreous housing which is preferably made of glass or wet process porcelain.

One of the principal objects of my present invention is to provide a compact, eicient switch for either indoor or out-of-doors use which is easy to construct and economical to manufacture. Compactness is obtained by having rotat- 'mg contacts for opening or closing the circuit which contacts do not require the space necessarily used by contacts having a rectilinear motion. Fewer parts add to the compactness of the switchrand contribute to lower costs of construction and operation.

Another object of my invention is to provide switch units that are readily mounted on the sides, top or ends of cross arms of power-line carriers, whichever is more desirable or convenient. Such mounting is not readily or practically attainable by switches which require mounting on a vertical panel and which have rectilinear motion.

A further object is to provide novel rotary contacts of the prestressed spring type. I'he bearing of these prestressed contacts may be either radial or axial and the type of engagement may be either of the surface type or of the point or high pressure type.

It is understood that any number of these units may be mounted side by side and operated by a common crank arm, or other control. In fact, this is one ofthe advantages of my invention.

A still further object of the present invention is the provision 'of substantially completely weatherproof units whose interiors optionally are visible without opening of the housing and are readily accessible for any repair work. These units have readily detachable cover plates of glass, transparent plastic or other transparent material. If preferred, however, covers of opaque materials may be used instead. An insulating liquid such as oil may cover the engaging contacts to assist in interruption of current flow.

A further advantage of these switches is their adaptability to use with high voltages with a high factor of safety:

These and other features and advantages will be more fully understood and appreciated upon l reference to the following detailed description taken in connection with the accompanying drawings wherein specific embodiments of my invention are disclosed.

In the drawings: Figure 1 shows a set of three rotary disconnect switches with vertical axes on a. cross arm of a pole which switches are all linked together and are gang operated by one bell crank;

Figure 2 shows another set of three rotary disconnect switches with horizontal axes on the cross arm of a pole, which switches are gang operated;

Figure 3 is a vertical longitudinal section taken along the line 3-3 of Figure 4 of a rotary disconnect switch with a vertical axis adapted, for example, to be mounted on the side (as in Figure 1) or end of a cross arm; y l' Figure 4 is a bottom View of the rotary switch of Figure 3 with a portion of the screen broken away to show the interior; l y

Figure 5 is a front elevation, withportions broken away, of a rotary disconnect switch with a horizontal axis adapted, for example, to be' placed on the side (as in Figure 2) or top of va necting the switches together on a single operat-Y ing axle;

Figure 9 is a vertical cross sectional view `of the form of rotary switches shown in Figure 8 (the section being taken substantially on the line 9-9 of Figure 8);

Figure 10 is a front elevation, partially in sec-v tion and with the cover plate removed, of a fourth style of rotary disconnect switch;

Figure 11 is a cross sectional view of the rotary switch of Figure 10 along the lines II-ll of Figure 10;

Figure 12 shows a detail view of the front of shown in the side the cover locking engagement; view in Figure 11; and

Figure 13 is a fragmentary sectional view of a modied form of contact such as may be employed in the device of Figures 8 to 12.

Referring first to Figures 3 and 4 showing the rotary disconnect switch 8, there is provided a two part housing of vitreous insulation preferably of glass or wet-process porcelain surrounding and covering the live portions of the switch.

The upper of the two parts of the housing is in holes in the support I9 and holes in the shoulders` I1 of the barrel I2. These bolts I4 are threaded, into pre-threaded metal inserts 2| which are cemented inside hollow bosses 23 which are integral parts of the cap I0. In this way the cap I0 is joined to the barrel I2 and the two parts of the housing are rmly secured to the metal bracket 20.

The bracket comprises two legs 24, 24 formed integrally withthe annular support member I9 for bearing the housing 8, which support member I9 has four cross arms 25 which brace the support I9. and at their junction carry an integral barrel 21 which contains a bronze or other antifriction metal bearing sleeve 28. This sleeve 28 bears an axle 38 which has an'enlarged end 3| which is cemented into a cavity within the insulator33 and which bears and turns on the collar 32 of the barrel 21. cemented within a second (and upper) cavity in the insulator 33 is a cylindrical metal stub 34 to which is secured by screws 35, 35 the laminated switch blade 31. On the lower end of the axle 39 is secured crank arm 38 for turning the axle and consequentlyv shifting the position'of the switch blade 31.

The switch blade 31 of the illustrated deviceis formed of four Ametal strips which are clamped together by cap screws 35, 35. The upper two strips are copper and thelower two are of phosphorus bronze which act as leaf springs and thus produce rm electrical contact between the copper of the switch blade 31 and the two stationary contacts 39, 39. "The contact may be flat sur'- face contact or it may be high pressure point contact. It will kbe noted that the stationary contacts'have beveled edges as at 36 so that the switch blade is directed downwardly as it comes into engagement with the contacts 39. This downward thrust deforms the blade 31 and permits the phosphorus-bronze leaf-springs to stead sits on an annular cup 41 of more or less yielding insulating material such as cork or compressible fiber. Between the support I9 and the insulating cup 41 is positioned a bronze screen 48 which ts snugly about the collar 32 of the barrel 21 andt which separates the interior of the housing from the open air. 'I'his screen 48 is primarily used to keep out dirt and insects which otherwise might get in and foul the surfaces of the stationary contacts 39 and the revolvable switch blade 31.

`As shown in Figures 3 and 4, the switch blade 31 is in engagement with the stationary contacts 39 so that there is a current ow through the rotary disconnect switch from one wire to another.

-But now if the han'dle 38 is rotated 90 the switch blade will be rotated become disengaged from the stationary contacts and lie in a direction parallel to the length of these contacts. In the construction of the switch, the size of the instrument is such that there will be a ,certain minimum distance between the stationary contacts 39. This minimum distance will depend upon voltage requirements. The screen 48 or bolts I5 may be connected to ground as an additionl precaution against arcing due to severe over-voltages.

The bracket 20 has holes 22, 22 in each leg 24 through which screws may be inserted for mounting the rotary switch. With the construction shown the switch could be mounted on the side or end of a cross bar or on the side of a post with'equal ease. Mounted on the side of a cross arm, for example, several of these units may be linked together by rods joining the handles 38 together. A hole 46 in the end of the arm 38 permits such linking so that a set of several switches may be activated by one crank. See crank v49, for example, in Figure 1. The operating cranks and the brackets 20 are preferably grounded. An advantage of the construction of Figures 3 and 4 is that a lineman may safely stand upon the cover III.

Figures 5. 6 and 1 are the several views of another style of rotary disconnect switch.

' Though the form is diierent the principle is the same, namely, an enclosed disconnecting switch with a double ended rotatable blade. It is necessary to have the contact elements Separated a' mon to all the devices illustrated in Figures 1 strongly force the upper surface of the blade ing post blocks 4I and a nut 44 is threaded on to y the end of the shank 40 of each stationary contact 39 so that the split binding post blocks will be squeezed and will tightly engage the ends of the wires. The shanks 40 of contacts 39 may beA cemented in permanent position.

The porcelain or glass housing does not rest directly on the annular metal support I9 but ina through 13. v

In Figure 5 the housing 5I) is also preferably of wet process porcelain or glass and has a glass or moulded insulating cover 5I bolted on the front side by bolts 53, 53 which permits a `view of the interior without the necessity of opening the housing. In the prior device of Figures 3 and 4 a View of the interior is possible through the bronze screen 48 in the bottom of the unit or to some degree through the housing if made of glass.

The binding posts or terminals 54, 54 which may be bonded in place have at their inner ends the stationary contacts 55, 55. Flanges 56, 56 bear against washers 51, 51 which rest against the inside of kthe walls of the housing 50. The

Shanks 58, 58 of the terminals pass through holes,-

in the walls of the housing and are fastened vfirmly in place by nuts 59, 59 threaded onthe tiallfy' the fll lehgth of the blade. But the i holritl portions have a U-shaped notch cut out ifi the ceite so that each blade 6I may be llied around the waist of the insulator 62, G i blade `(see Figures 6 and'l) is slipped around 'waist of the insulatorl 62 from the left side Bhd che froi the right side. Tifie'se' blades 6| are connected in parallelspaced relation .by the bolts 53,53 and spacers' B5, 65. The heads and of these bolts rest on coiled springs 64 of the bed sil'ng type so that the blades may be resiliently forced apart against the prest'ress ci the snnnss u, 64 when they swing into engagewith the fixed contacts 55. 'I'lie spacing cylinder Il around the shank orA each of the bolts salles between the blades el and has a length slightly' less than the thickness of the contacts 55, 55 which the blades sl engage. Each 'at each of its ends has a lateral convex tact A'rlger 66 stax'iiped out to form a high pressure line contact in engaging the stationary contacts 55. l

it can be noted from Figures and s that the insulator 62 has a notched central circular harige "portion el which nts between the blades el and' the hotches of whichvpai'tial-ly surround the cyllndrlcal spacers 65 Also, there are flanged ends lo on the insulators! and a cylindrical hole 69 through the center of the insulator thi'oilgh which runs the hexagonal bar 1U. This .bis has, within the housing, a metal sleeve or'shell 1l covering it. The shell 1l is cementedfli-'inly as at 12 within the hole 69 with its longitudinal axis coinciding with that of lthe hole. The bar has bearing collars which are truni'lioiid irl metal bearings cemented in the 'side walls of 'the housing 5u as at 1a. when the bar n is inserted through the bearing collars l'and the, shell 1I, then rtationof the bal n will result ifi rotation of the insulator also ofthe blades 6| since the expanded central portion 61 of the insulator 62 will exert leverage ahst the cylindrical spacers 65 which are aui'ld the `bolts 53. otatirl'g the bar 1U through ah angle of 90" willdisengage the blades 6I from the statio'lary contacts 55 and position these blades 6l in the dotted line position of Figure 6.

The housing 50 (see Figures 6 `and 7)v has threaded inserts 1l cemented in its back wall for screwing the unit on tovthe side or top o f, for eiarple, a. cross arm. This prevents the housix'lg from rotating about the bar 'I0 as an axle and permits the b ar to rotate the switch blades 6| `its above described.`

A gang of three switch units 58 for three phase circuits may be mounted next to each other. Figure 2 shows such circuits and style of mount*- ing with switch units of a different design. A single rod, such as rod 1l in Figures 5; 6 and 7 (or rod 9i in Figure 2) then passes through the whole group of rotary vswitches which are then operated o by a single crank 89. The rod is mounted at "each outer 'end in its own bearii'ig brackets, such as brackets 9E of Figure 2. which are fastened to the cross ann and which :hay be grounded. y v n opposed lateral fingers t6 on the ends of the blades 6lA are separated by a distance slight-i ly less than the thickss of the stationary cofre tacts 55 which they are to engage. Ti'lerefo'-e porl rotation of` the blades into hgagenht with the cltacts 55, the blades are spread slight` 1y against the opposing action of the prestressed sprn'gsilllz This results in positive pres'trssed high pressure Contact between the blades 6| ai'l'd contacts 55. When the blades 6I are in dische gaged position they are, by design, separated from the contacts by a distance Which yiS b than the striking distace to metallic sleeve TI or shaft 10 which are grounded.

Figures 2,- 8 and 9 illustrate another forth of rotary disconnect switch but one having the same' general characteristics as the prior two. There is a wet process porcelain or glass Iii'iilsin'ii,r 80 having a removable 'glass or other i'rloulded ine sulation cover 8| attached thereto as by' a "Baken lite lrirn 83 and screws 82. Extending through the walls of opposite sides of the housing are bolts 84, 84 which have at their inner ends the stationary contacts 85, 85. The nuts 86, 86 o are threaded on to the threaded ends of the bolts stand nx the stationary contacts a5, firmly in place against Washers 81, 81 which separate the contacts 85, 85 fror'n th'e inside of the walls of the housing 80. A second hut 88 on each bolt 84 binds the current-carrying 'wire (not shown) against the n'ut 86.- 'Ihe bolts Il, 84 may be cemented in place. There is provided, as in the case of the other switches, 'a

ground connection which is' closer to the ` contacts 85, 85 of the switch of Figures 2i, 8 and 9 than the contacts are to each other.

The movable contact points 90, 90 are indirectly carried on the cylindrical rod 9i as will be described. Bearings indicated at!! are cemented as at 93 into the side walls of the .housing 80 to support the round rod 9 l. Each of these bearings 92 has a strap 92a (see Figure 9) extending along the outside flat wall 'of the housing of the unit. The strap 92a has an rlturned lug 92o lying' in a notch in the edge of the side wall. The lug 92o is threaded to receive the s'cle'w 82 at each side'for holding the cover over the open side of the housing.' The shaft 9! with its key 98 can be inserted from the side through the opening in bearing sleeve 92. The lkey then is brought into register with the keyway in hub member |00, as shown in Figures 8 land 9. Thin metal sleeves '92e of a thickness suitable for taking up the dilerence in diameters between the bearings 92 and the shaft 9| are then slipped over the adjacent ends ofthe shaft. Collars 92d 'are fastened as by set screws upon the shaft 9| at each side of the single unit or upon the shaft when'the ends project 'from a gang 'of units. The sleeves 92'c abut against said collars 92d at the outside and when 'a gang of units is placed side by side as in Figure 8, the sleeves 92o of adjacent units 'abut 'eri'd'wise against each other. Thus the movable switch 'rnernbers are held in register with the stationary contacts and the shalft is made to lill the stationary bear'- ingr sleeves. Separate from the housingr and at either side of the rotary ydisconnect switch, vor 'a group of them, are bearings 94 which are carried by brackets 9s. The brackets 96. one for each end of the rod, are fastened by screws 'or bolts to a cross armo (for exan'iple see Figure 2), "and may be 'grounded if desired. As shown in Figure l2, a

single crank l'89 can their operate on the one cylindrical rod 9| and operate as many rotary switches as there are mounted in the group. Through a hole 91 in the back Wall of each housing 80 (see Figure 9) extends a bolt or screw 90 which is fastened to a cross bar 96 running between and fastened to the brackets 96. This prevents ,the housings from revolving on the rod 9| as an axle. Bolt 99 is preferably grounded.

Keyed to the rod by Woodruff key 38 is the close-fitting sleeve or hub |00 with four longitudinal ridges or keys |0| which run parallel to each other.` This rod and sleeve are cemented as at |02 toY the inside of the waist |03 of the insulator |05. The waist |03 has a cylindrical bore but a hexagonal exterior; the insulator |05 has a generally cylindrical exterior except for the waist |03. It will now-be apparent that rotation of the rod 9| will cause the insulator |05 and anything fixed to it to rotate also.

Clamped to the waist |03 of the insulator |05 is a copper braid |00. This serves both as a current conductor and as a cushion. The clamps |01 and |08 conform to the hexagonal exterior of the waist |03 but do not completely encircle it as may be seen from Figure 9. These clamps |01 and |08, clamp the copper braid |06 to the waist |03 of the insulator |05 by means of bolts |09 and ||0 which run through their parallel ends. (See Figure 9.) These bolts also pass through holes in the copper braid |00 as may be seen at of Figure 8.

Clamp |01 (left hand clamp of Figure 9) at each of its ends has upper and lower parallel arms ||3 and ||4 at one end and ||5 and H6 at the other end (see Figure 8). These pairs of arms are joined by webs |1 and |8 respectively. Beyond the webs ||1 and ||8 the pairs of arms are still parallelbut are spaced apart a greater distance and are substantially greater in width. Within the lends of these pairs of arms are rectangular slots as at |20. The two clamp and arm members are thus identical.

The movable contacts 90 are soldered to the copper braid |00 which is capable of conducting the current from one movable contact to the other around the waist |03 of the insulator |05. The braid |05 is in turn soldered to iiat metal straps |2| and |22 which have turned down ends as at |23 which ends ride within and are guided bythe slots |20. Optionally, pins or rivets may extend through contact 00, braid |06 vand backing straps i2! and |22. A prestressed spring such as |25 keeps said\ straps |2| and |22, braid |00 and movable contacts 90 pressed outwardly from the center or the rotatable assembly under prestressed spring load as far as the slots |20 or an intervening object (such as the stationary contacts 85) will permit. When the movable and stationary contacts are brought into engagement, these springs, such as |24, insure smooth engagement and rm contact due to their being compressed between the webs |1 and I8 and the straps |2| and |22. These springs are held in place by Aa protrusion such as |21 at the center of the web |.|1 which ts within the coiled spring. The springs |25 are preferably but not necessarily of the bed spring type.

Optionally the fixed and movable contacts may be of the spherical high pressure type as illustra'ted in Figure 13. In this construction the stationary Contact 05 is a button head on the bolt 84 i. e., it is spherical. Likewise, the movable contact member 00 is spherical on its engaging face. The resulting engagement isv limited to a very small area, theoretically a point. Various forms of contacts may be made suchas a flat lsurface on the stationary contact and one ormore rounded projections on the movable contact or vice versa.

v The rod 9|, when rotated through an angle of carries the movable contacts 90 through an angle of 90 to a position at right angles to that shown in Figure 91. This rod 9| may run through the center of a group of these rotary disconnect switchesplaced side by side and may be operated by a single crank as shown in Figure 2. The individual rotary switches are so constructed that when placed side by side as shown in Figure 8 they are still properly spaced laterally so as `to be used without danger. Furthermore, the mov'- able contacts 90 and braidl 06 when in open position are so spaced from the stationary contacts as to afford complete safety.

Figures 10 and 11 illustrate another style of rotary disconnect switch. In design it is more like the switch of Figures 8 and 9 than the other prior forms. A glass or wet-process .porcelain housing |30, has holes through its sides as at |3I. (See Figure 10.) Through the center of these holes runs a hollow sha-ft |34 and about the shaft |34 may be placed sleeves of insulation as shown at |35, |35. If the sleeves |35 are omitted, shaft |34 may be made to serve as a connection to ground. Keyed, as at |30, to the hollow shaft |34 is a cylindrical metal hub |31 having four longitudinal ridges |33 equally spaced on its periphery and running parallel to eachother. The cement |39 binds the insulator |40 to the hub |31 which is keyed to the hollow shaft |34. Consequently, if the shaft |34 is rotated in its bearings as at |33 in side plate hubs |88 then the insulator |40 and anything atached to it will rotate also.

Around the waist |42 of the insulator |40 is cemented, as at |43; an annular ring |44 which has arms |45 and |40 extending outwardly on opposite sides. At their outer ends each of these arms |45 and |40, is forked, providing iingers |41 and |48, the .outer ends oi which extend parallel to each other. These parallel extensions of |41 and |48 have rectangular slots |50.

Copper braid |5| for conducting the current from one movable contact |52 to the other mov-1. able contact |53 is pinned or otherwise fastened, as at |54, |54 to the annular ring |44. This conducting braid is soldered on one side to the inside surface of the movable contacts |52 and |53 and on the other side to flat metal mounting straps |55 and |50. These parts |52, |5|, and |56 may optionally be fastened together by through rivets;y

as well as by solder. These mounting straps |55, |56 have their ends turned back to partially en, compass coiled springs, such as |51, and also to provide offset extensions which fit into the slots |50 of the extension arms |41 and |48 where they are guided during their movement and serve to restrain the radial travel of the movable contacts.

The prestressed spring |51 tends to push the strap |56 and consequently the braid |5| and further compressed. This assures rm contact.

The form of the contacts |52 and |59 may optionally be as described above in connection with Fig-l ure 13.

The stationary contacts |59 and |60 eachhavef threaded shanks ISI, ||i| which pass throught holes ln the walls of the housing |30 and permit these contacts to-be bolted firmly in place. These Shanks also serve, in cooperation with appropriate nuts, as binding posts or terminals for the wires carrying the current (wires not shown). i

' The rotary disconnect switches of my invention are preferably gang operated but obviously' may be segregated and individually operated. In Fige ure left side there is indicated the edge of an adjacent rotary switch unit |65. A ring of insulation or packing |66 separates the porcelain or glass housings. At each end of the single unit or groupv of units the holes |3| are closed off by plates |61 (see Figure 10 and also dotted outline on Figure 11).1 Plate |61 has a hub |68 which lits within the eye |69 of the supporting bracket |10. The hub |68 is divided by a wall |12 into two chambers. The right hand chamberA |13 of Figure 10 contains one extremity of the shaft |34. This chamber |13 is open on the side toward the observer so that a crank arm (not shown) integrally formed on the collar |14 may protrude therefrom. The collar |14 is keyed to the shaft |34. 'I'he aforementioned crank arm is fastened to usual cranking means which thereby opens orv closes the switch. l Y

A closure plate' |15 closes the end of the chamber |13 and it is held in position by the tie rod |32 which extends the full length of the hollow shaft |34. This rod |32 which is anchored at the right in the anged nut |15 extends through a similar closure plate at the, other end and through a washer or flanged nut like nut |15 which is threaded or bolted on to the rod |32 at its other end. When the clamping plates '|15 are drawn up tight on the threaded ends of the rod |32, all the housings of the gang switch and the side plates |61 are pressed tight against each other and are thus clamped together as a single unit. i

As indicated before, the shaft |34 is carried at each end in bearings |33 in the walls |12 of plates f Each switch unit has its own cover such as |11 which is preferably made of glass, transparent' plastic or an opaque insulating substance such as "Bakelite. A transparent cover permits the op` erator to see whether the switch unit is in open or shut position. To make repair of these switches easier, each cover is fastened on to one long metal bar |18 as by screws |19, |19 (seeV Figure 11). -The bar runs parallel tothe shaft |34v and rod |32 but on the outside of the housing |30. Then when the .bar |18 is swung down into proper position all the covers are simultaneously swimg into closed position. y

To hold the bar in place so that all the housings will be held in closed position there is placed at each end of the gang of housings a locking means. This locking means consists of an arm |80, (Figures 11 and 12) pivotally mounted on a bolt extending through an ear |19 formed on each closure plate |61. bears against the flat side of the end of the bar |18. Arm |80 is held tight against this strap |18 by a swingably mounted draw bolt |8| which is swung into a slot |82 (see Figure 12) and clamped therein by wing nut |84 and which is grounded.

The ldraw bolt |8| is itself pivoted so that it may be swung to the right (Figure 12) when the nut |84 is loosened so that the pivoted arm |80 may then be swung away from the strap |18. The draw bolt |8| at its left end (Figure 11), encircles a bolt |85 carried in iianges |86, |86. These anges are formed integrally with the eye |69 of bracket |10. 'I'hls construction permits the The outer end of the arm 80 ff movement of draw bolt |8| into and out of locking engagement. i

The switch housing unit `does not pivot within the-eye |69 of the bracket |18 since thefollowing rigid elements hold it in upright position: Each bracket '|10 is iixed e'. g., toa crossarm or upon a common base such asa piece of channel bar; its eye |69 being integrally formed is rigid; the flanges |86, |86 formed integrally von the eye |69 are rigid and carry the draw bolt |8| which is also rigid when bolted in locking engagement :with the pivoted arm |80. Draw bolt |8| cannot drop into the slot |82 of arm |80 unless the arml |80 and the strap |18 beneath it are in the same vertical plane as the cross arm or mountingY base on which the whole gang oi units is mounted. Therefore when the covers |11 are locked'on by the abovedescribed locking arrangement the units are lined up perforce vertically, with their'terminals |6|, l6|`in vertical position.'

As has'been said of all the prior switches (Figures 3 through 9) the opening and closing of the switch can be accomplished in anV insulating housing in the least necessary space by the rotor .1 switch arrangement Vof my invention. No spacelling panels are necessary..` Furthermore, lthe stationary and movable contacts are always pressed tightly together when in engagementwith each other. A still furtherfadvantage is that these devices are inexpensive and readily assembled; -their insides are easily seen and they may be opened for repairs very quickly. y

Though these rotary disconnect switches are adapted to serve n conjunction with circuit breakers and to further isolate and open sections of the circuit interrupted first by the larger and more expensive circuit breakers, yet these rotary A switches are adaptablefor use -to interrupt low current values such as normall load. `When the devices shown in vFigures 5f through 12 are mounted .on the top of a crossarm-for they have been constructed to per-mit this-they may be partially lledwith oil, in their bottom portions, for the housings are made of glass or`wet process porcelain and will not leak. Then the making and breaking ,of the lower contacts `will take place in the oilwith the'movablecontact swinging out ofv and standing above `the'level yoi theoil.

Switches of the present type are particularly i designedfor power circuits' ofithe orderof 7500 volts or less and .capable oi carrying 200 amperes. It will be observed that in each' 'form a double break is secured. This insures speedy interruption of any current flow and provides ample clearance. An important advantage, particu larly of the forms shown in Figures 5 to 13, is the ability to space the units of a gang on the same centers as the run of conductors. So far as I am aware this is broadly new in rotary enclosed disconnect switches. Thus enclosed disconnect switches of the present rotary type may be inserted into existing runs of conductors spaced on minimum striking distances. (See. for example, runs of conductors indicated at A, B and C of Figure 2.) These switches are adapted for both indoor and for outdoor service. It will be noted that by swinging the blades in the plane of the conductors, see Figure 2, and enclosing the individual switches in housings of high insulating value, a very compact and Widely useful structure is provided.

Where the spacing of the phase conductors permits or where room on the cross arm or other mounting is available, the form shown in Figures 13 and 4 is highly advantageous particularly for out door service. It may here be noted too that the vertically rotatable switch elements andthe stationary contacts of the devices illustrated in Figures 5 through 12 are readily adaptable for operation in a horizonal plane of rotation as used in the device of Figures 1, 3 and 4.

While I have described in detail the construction of various specific forms of my invention, it is to be understood that numerous equivalents and modifications may be employed without departing from the spirit and scope of my invention. Furthermore, Ido not intend to be limited by such details ofgthe embodiments illustrated and described above except as they are set forth and made a part of the appended claims.

I claim: x

1. In a high tension disconnect switch the combination of an outer substantially enclosed housing of insulation having a circumferential wall, stationary switch contacts mounted in said housing forV direct connection to line wires, a shaft disposed substantially axially of the said circumferential wall, a double ended blade lying in the plane of the contacts, an insulator mounted on said shaft and supporting said blade, a grounded element within said housing closer to one of said stationary switch contacts than the distance between said stationary switch contacts, and operating means for rocking said shaft back and forth through substantially 90 to cause the blade to engage and disengage ,said

contacts,

2. In an electrical high tension switch, in combination, an outer substantially enclosed housing of vitreous insulation, a. pair of stationary electrical terminals disposed on the inner surface of said housing, a rotatableswitch member disposed within said housing for making and breaking contact at both ends thereof with said stationary contacts, a metal shaft rotatably mounted in said housing, a porcelain insulator fixed to said shaft and carrying said rotatable switch member, and a grounded element within said housing closer to one of said stationary electrical terminals than the distance between said stationary electrical terminals.

3. In combination, a gang of high tension disconnect switches each switch having an outer substantially enclosed housing of electrical insulating material and individual rotatable switch arms, the housings being arranged to provide an electrical insulating, barrier between adjacent switches, stationary electrical contacts mounted in each housing for direct connection to line wires and a common axle extending through said housings for operating the rotatable switch arms. of each of said disconnect switches simultaneously, said axle being individually insulated from said switch arms inside the housings, Aand a grounded element in each housing closer to onel of the stationary electrical contacts therein than the distance between the stationary contactsl within each of the housings.

4. In combination, a plurality of high tension disconnect switches each comprising a -substantially enclosed outer housing of electrical insulating material and substantially oppositely ,y

electrical terminals of each housing, a rotatable switch arm within each housing, a lporcelain insulator for and carrying each switch arm, said insulators being individually keyed to said shaft for rotation therewith,4 and a ground closer to one of the stationary electrical terminals ofv each housing than the distance between the opposed stationary electrical terminals therein, said housings having wall portions formingan insulating barrier between adjacent disconnect switches. l f

5. In combination, a`plurality of high ,tension disconnect switches each comprising a housing of electrical insulating material and substantially oppositely disposed electrical terminals mounted in said housing and extending thereinto, said housings each being provided with a doorof insulating material providing access thereinto and'` forming a substantially enclosed chamber, a,

common metal shaft extending through said housings on an axis intermediate the oppositely disposed electrical terminals of each housing, a rotatable switch arm in each housing, a porcelain insulator for and carrying eachA switch arm, said insulators being individually keyed to said shaft for rotation therewith, and a grounded element for each switch carried by the door ofeach.

housing, said grounded element being closer to one of the electrical terminals of each switch terminals thereof.

FEDER B. HOYE.

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