US2287250A - Circuit breaker - Google Patents

Description

MAKERS & BRLAKL June 23, 1942. lLEMAN 2,287,250

CIRCUIT BREAKER Filed June 22, 1940 3 Sheets-Sheet 2 Aw ATTORNEY 'LUU. [Ltblhlbll blHbUH 53 trtfltwbt Search Room MAKERS & BREAKERS,

June 23, 1942. E .LEMAN 2,287,250

I CIRCUIT BREAKER Filed June 22, 1940 5 Sheets-Sheet 3 INVENTOR 621/; d haw/21v BY i y/(Q? is ATTORNEY Patented June 23, 1942 UNITED STATE PATENT QFFICE CIRCUIT BREAKER Pennsylvania.

Application June 22, 1949, Serial No. 341,790

16 Claims.

This invention relates to various features of improved construction in circuit breakers. The breaker is of an enclosed sealed type and adapted to be used in subways, manholes'and other locations where it may be subjected to excessive dampness or even submerge-:1 in flooded areas. Although particularly adapted for such use, various features of the invention are applicable for use in circuit breakers generally.

The main objects of the invention are to provide an improved circuit breaker which will be of rugged and durable construction, of comparatively large current capacity and adapted for comparatively high voltages, and dependable in operation, and particularly adapted for use in damp or flooded locations. Another object is to provide means for raising and lowering the separable lower tank together with the operating mechanism for convenient inspection and repair. Another object is to provide a simple form of interlock for preventing the lowering of the operating parts while the breaker is closed and for preventing the return to position unless the breaker is open. Other objects and advantages will be understood from the following description and accompanyin drawings showing a preferred embodiment of the invention.

Fig. 1 is a vertical section on the line l-i of Fig. 2; Fig. 2 is a vertical section at right-angles thereto; Fig. 3 is a bottom view of the upper en- 51 closing head; Fig. 4 is a plan view of the removable tank and plate which supports the mechanism and contacting parts; Figs. 5 and 6 are views showing the parts in different positions whereby the interlocking is obtained; and Fig. i is a section on line l! of Fig. 1.

The top portion H of the enclosing casing is of rectangular form and dome-shaped at the ends and is provided with upwardly extending projections Ilia for supporting the breaker from above. It is provided with a rectangular opening ltlb in its lower portion, as well shown in Fig. 3, for receiving parts supported by the lower casing H. The lower face of the top is finished around this opening to receive a gasket l2 so as to form a tight joint between the two parts of the casing. Each end of the top casing extends beyond the lower tank and is provided with three openings Hic for receiving cable wiping sleeves l3 which are clamped to the underside of the openings Hlc with intervening gaskets to form tight joints, as shown in Fig. 2. The external cables l4 pass upwardly through the sleeves and openings lllc, being sealed at the sleeves l3.

The inside top portion of the casing is provided with four lugs Hid and a pair of fiat metal bars M are bolted to the underside of these lugs. Six insulating post bushings 15 are bolted to the underside of these metal bars and project downwardly, each of these bushings supporting at its lower end a conductor l6. They extend horizontally and are provided with downwardly extending end portions lEa and lBb. The latter form the fixed contacts of the disconnecting switches while the former provide means for connecting thereto the ends of the incoming and outgoing cables l4.

Across the center of the top portion l0 extends an insulating partition H which separates the terminals of the incoming leads from the terminals of the outgoing leads, as shown in Fig. 2. This partition is supported at it ends, as shown in Fig. 1, by bent sheet metal supports l8 which in turn are secured to the inside portions of the top casing by bolts l8a. The inside top part of the casing I0 is provided with a longitudinally extending and downwardly projecting rib Hle which receives yieldable Y-shaped clips l8b fastened to the top of the partition H, as shown in Fig. 2, for the purpose of holding the part in fixed central position. On each side of the central barrier I! is supported another central insulating partition l9 having secured thereto a pair of outwardly extending insulating partitions or barriers 20 and to the lower ends thereof are secured horizontally extending insulating partitions or barriers 2|. These two outwardly extending barrier sets are separately assembled and have their part fastened together by metal angle pieces 22. The barriers 20 extend between the disconnecting contacts and the terminal connections and the barriers 2| extend horizontally and surround each of the downwardly extending bushings 23. The two barrier sets are held in place by their central partitions IS). The Y-shaped clips l8b are provided with downwardly extending yieldable inverted Y portion I80, as shown in Fig. 2; and to each side of the lower portion of the partition ll are secured upwardly extending clips 24. The barrier sets are placed in position by inserting them through the opening lGb of the top casing and then slipping the partitions I9 up under the clips I and then letting them drop slightly to engage the clips 24. The complete barrier assembly thus provides insulating partitions between the incoming and outgoing leads and connections and also between the connections of the different phases. Each barrier set may be separately removed or replaced and the removal of a set at one side ZUU.

2 2,287,2o per 18%166211316 connections to be accessible the supporting plate 29.

while the other side still may continue to be alive and protected by the barriers. The barriers insure safety to anyone working on the breaker as they prevent the hands or head from coming in contact with live connections.

The lower tank I I is surrounded at its top portion by an angle iron 25 which is welded to the tank. This angle iron engages the gasket l2 when the tank is in its raised position and forms a sealed joint. Four threaded rods 26 are located outside of the lower tank near each of its four corners and are firmly fixed in tapped holes 26a in the top portion of the casing as shown in Fig. 3. The rods 26 extend downwardly a considerable distance along side the lower tank and have long lower threaded portions which are engaged by nuts 21 having elongated downwardly extending sleeves 21a, as shown in Fig, 2. Fixed to the sides of the tank are four angle plates 28 through which the rods 26 freely pass. The angle plates 28 rest on top of the nuts 21 which form a support for the tank. It is apparent that by turning the nuts 21 the tank may be raised or lowered. When it is desired to remove the tank, the nuts 21 are turned to permit the gradual lowering of the tank and its removal for inspection or repairs after the nuts 21 and their sleeves are removed from the rods 26. When the tank is in its normal position as shown in Fig. 2, the tightening of the nuts serves to force the tank firmly against the gasket l2 and holds the parts in a sealed connection. The rods 26, together with the flanges 28 and nuts 21, not only serve to hold the tank in sealed connection with the top portion, but the rods, by their elongation and their passing through the flanges 28, serve as guides to bring the parts of the disconnect switches in proper alignment before they are engaged and while the tank is being raised to its final position by the turning of the nuts 21.

Within the tank and near the top is a metal plate 29 which substantially encloses the top of the tank and serves to support the conducting parts and operating mechanism. The plate is supported upon four angle plates 30 which are welded to the inside of the tank, the plate 29 being bolted to the angle plates by the bolts 3|. The six conductor bushings 23 pass downwardly through openings 23a in the plate 29 and are secured to the plate by clamping means 32 bolted to the plate. The conductors within the bushings 23 are provided with upwardly extending yieldable disconnecting contacts 33 which engage the extensions lfib of conductors l6 when the tank is raised to its normal position. The lower ends of the bushing conductors are provided with extension plates 34, 3441 which support the fixed and movable contacts of the breaker. Pivotally mounted between the lower ends of the plates 34, as shown in Figs. 1 and 2 are three sheet metal U-shaped elements 35 which are respectively boltedto the movable elements 38 which carry the movable contacts 36a of the breaker. Three laminated flexible copper strips 31 connect the lower ends of three of the bushing conductors to the movable contacts respectively for forming good electrical connection therewith. Pivotally connected to the U-shaped members 35 are three operating rods 38 of insulating material which extend upwardly and are connected to the operating mechanisms.

The breaker is opened and closed by the angular movement of a shaf t 39 which passes under lJlriUSS REFERENCE Search i Three pairs of plates 40 are pivotally connected to the shaft 39 and extend downwardly and are bolted to the sides of the rods 33 respectively. Fixed to the underside of the plate 29 at opposite ends of the shaft 39 are two shaft hangers. One of these shaft hangers 4| at the left of Fig. 1 is bolted to the plate 29 by a pair of bolts 41a, as shown in Fig. 4, and has an offset projection for supporting the shaft 43. The opposite shaft hanger 42 is fixed to the underside of the plate 29 by bolts 42a, as shown in Fig. 4 and supports the shaft 44. The inner end of the shaft 43 engages a plate 45 which is shown extending upwardly in Fig. 1 to receive the left-hand or front end of the shaft 39. The inner end of the shaft 44 engages a plate 46 which extends upwardly in Fig. l to receive the rear end of the shaft 39. The upper end of the plate 46 also carries an inwardly projecting pin 41, the purpose of which will be later explained. The ends of the shafts 43, 44 and 39, and the end of the pin 41 are brazed to the plates 45 and 46. The front end of the shaft 39 extends beyond the plate 45 and has the lower portion of the projecting end cut away, as shown in Fig. 1, for the purpose later explained.

At the front side of the breaker, as shown at the left of Fig. l is the actuating shaft 48 which projects through the wall of the tank and is journaled on the outer end of the shaft 43. A stufling .box 49 is bolted to the side of the tank by end extensions, and as shown in Fig. 1 retains the actuating shaft 48 in position, a gasket 50 between the end of the stuffing box and the tank serving to form a sealed joint. The outer end of the stufiing box is normally closed by a threaded cylindrical cap 5| which is threaded to the body of the stuffing box 49. The inner end of the actuating shaft 48, as shown in Fig. '1, is partially cut away angularly to form a wide angular space 52 and the front end of the shaft 39 projects within this space and may thereby be engaged by remaining end portion 52a of the actuating shaft 48. It is evident that when the actuating shaft is turned, the walls 521) and 520 of the space 52 Wlll engage the projecting end of the shaft 39 and move it angularly about the axis of the shafts 43 and 44 in either direction, together with the supporting plates 45 and 46, to close or open the breaker. The parts are shown in the closed position of the breaker, at which time the shaft 39 is vertically above the axis of the shafts 43 and 44, as shown in Fig. 1. lhe breaker contacts are then closed as shown in Fig. 2. When it is desired to open the breaker, the actuating shaft 48 is turned to move the wall 521) of the space 52 away from the shaft 39 and after being turned about the other wall 520 of the space 52 engages the shaft 39 and turns it, together with the plates 45 and 46, about the shafts 43 and 44 to open the breaker. When the initial opening action occurs, the spring pressure of the contacts and the weight of the parts will cause a quick opening movelnuit and a rapid separation of the contacts. In this action the shaft 39 leaves the opening wall 520 and is free to move in the space 52 to full open position without further movement of the actuating shaft 43. This structure thus prevents a slow separation of the contacts and avoids the contacts being held in a partly open position, regardless of how slowly the operator may turn the attuating shaft. The closing of the breaker is, of course, accomplished by turning the actuating shaft in the opposite direction.

In order to turn the actuating shaft of the breaker, the cap BI is removed and replaced by the wheel 53, shown in dotted lines in Fig. 1 which fits over the outer end of the shaft 43 and has an outward extension 53a carrying a spring pressed plunger 53b which engages a radial hole in the shaft 48. It is evident that by turning the wheel 53 the breaker may be opened or closed and for convenience the wheel may be operated by a chain or belt from the top of the manhole in which the breaker is located. The wheel 53 may be readily removed by withdrawing the plunger or pin by means of the knob 53c and withdrawing the wheel from the shaft, after which the cap 5! may be replaced. In the side of the tank, as shown in Fig. 1, is an opening which is covered by a sealed glass plate 5'1. This serves as an oil level indicator. Opposite the opening within the tank is a position indicator plate 55 which is suitably inscribed to indicate whether the b1 eaker is opened or closed, such as by the terms off and on. This plate is shown secured to one of the rods 38 by a metal strip 53. When the breaker is closed, the plate 55 is raised b, the upward movement of its rod 38 and the symbol on is then positioned opposite the glass plate When the breaker is open, the deter rd movement of its red 38 moves the plate 5?: a: '.vn\'.';-.rri.y and the symbol 051" is then opposite the glass plate E54 to show that the breaker is open.

Interlocking means is provided for preventing the tank from being lowered and interrupting the circuit at the disconnecting switches when the breaker is CIOSCL; and also for preventing the engagement of the disconnecting switches when the tank is being raised to operating position unless the breaker is open. For this purpose, a pair of brackets 51 is provided. one bracket being secured to the front side of the top casing by the bolts lBa and the other bracketocing secured to the rear side of the easing by the bolts lfia, as shown in Fig. 1. These btackets are offset inwardly and extend down through openings in the plate 29 and pass one side olthe shaft 39. These brackets are provided with hooks Ha at their lower ends, as shown in Figs. 5 and 6 which project toward and under the shaft 39 when the latter is in its uppermost position. Fig. 5 shows the rear shaft hanger G2 and shows the relative position of the shaft 58 to the hook 51m of one of the bracketc when the breaker is closed. if it should be attempted to lower the tank and the operating parts when the breaker is closed, the end portions of the shaft 39 would engage the hooks 51a bei'ore the disconnecting contacts 33 separated from the extensions iiib. The hooks 57a would thus prevent the opening or" the circuits at the disconnecting switches and at the same time prevent any further lowering of the tank. it would therefore be necessary to raise the tank sutficiently to separate the end portions of the shaft 39 from the hooks 57a, after which the breaker could be opened in the manner already described. The opening of the breaker would bring the parts to such a relative position that the shaft 33 as well as pin 7 would be below the hooks Sid and the tank could then be lowered without interference by the hooks. The continued lowering of the tank would then separate the disconnecting switches without subjecting them to the eiTects of opening the circuit. *Now suppose that it is desired to replace the tank in operating position and let it be assumed that the breaker is then in its closed position. At that time the axis of the shaft 39 is above the axis of the shafts 43 and 44, as shown in Fig. 6. This brings the pin 4'! under the hook 51a of the rear bracket and any attempt to raise the tank is prevented by the pin 41 engaging the underside of its hook 57a. Thi halting of the movement of the tank occurs before the disconnecting contacts 33 can engage the fixed contacts lb. Consequently, in order to bring the tank up to its normal position, the circuit breaker mustbe opened which action wil swing the pin 4'! out from under the hook 51a to a position below the shaft 44. The tank may then be raised to its final position, after which the circuits may be closed by the closing of the circuit breaker contacts. Thus the closing of the circuit at the disconnecting switches is prevented. This interlocking means thus protects the disconnecting switches from opening the circuit at their contacts and likewise prevents the closing of the circuit at their contacts and enforces the accomplishment of such results at the circuit breaker contacts which are designed to withstand such action. The tank is, 01 course, filled to a proper level with oil at the center of the winds-w and the supporting cover plate 29 tends to prevent the splashing or forcing of the oil into the top casing. The insulating barrier plates 2| and Z0 likewise tend to protect the disconnecting switches and other parts from the oil.

Although a particular embodiment of the inention has been described, it will be understood that various modifications may be made therein without departing from the scope of the invention and that various changes may be made to adapt the breaker to particular requirements.

I claim:

1. A circuit breaker comprisinga top casing. a lower tank in sealed connection therewith and downwardly removable from the top casing, disconnecting switches within the top casing, a support carried by and within the upper portion of the tank and removably connected within the tank, insulators containing conductors secured to and passing through said support, said conductors carrying the movable contac s of the disconnecting switches at their upper ends, make and break contacts at the lower ends of said conductors, and operating means for said last named contacts supported by said support.

2. A circuit breaker comprising a top casing, a lower tank in sealed connection therewith and downwardly removable from the top casing, disconnecting switches within the top casing, a support carried by and within the upper portion of the tank and removably connected within the tank, insulators containing conductors secured to and passing through said support, said conductors carrying the movable contacts of the disconnecting switches at their upper ends, make and breaker contacts at the lower ends of said conductors, and operating means for said last named contacts located below and supported by said support.

3. A circuit breaker comprising a top casing, a lower tank in sealed connection therewith and downwardly removable from the top casing, disconnecting switches within the top casing, a support carried by and within the upper portion of the tank and removably connected within the tank, insulators containing conductors secured to and passing through said support, said conductors carrying the movable contacts of the disconnecting switches at their upper ends, make and break contacts at the lower ends of said conductors, an angularly movable shaft below said support for opening and closing said last named contacts, pivotal supports for said shaft below and supported by said support, and means for actuating said shalt from the outside of said tank.

4. A circuit breaker comprising a top casing, a lower tank in sealed connection therewith and downwardly removable from the top casing, disconnecting switches within the top casing, a support carried by and within the upper portion of the tank and removably connected within the tank, insulators containing conductors secured to and passing through said support, said conductors carrying the movable contacts of the disconnecting switches at their upper ends, make and break contacts at the lower ends of said conductors, an angularly movable shaft below said support for opening and closing said last named contacts, pivotal supports for said shaft below and supported by said support, and means for actuating said shaft from the outside of said tank, said actuating means having a sealed connection with said tank.

5. A circuit breaker comprising fixed and movable contacts, an angularly movable element for controlling the movement of the movable contacts, disconnecting switches associated with said breaker, and a permanently fixed stop engaged by said element when the breaker contacts are closed for preventing the opening of said disconnecting switches when the breaker is attempted to be moved in a direction to open said disconnecting switches.

6. A circuit breaker comprising fixed and movable contacts, an angularly movable element for controlling the movement of the movable contacts, disconnecting switches associated with said breaker, and a permanently fixed stop engaged by said element when the breaker contacts are closed for preventing the opening of said disconnecting switches when the breaker is attempted to be moved in a direction to open said disconnecting switches, said element being moved out of the path of said stop upon the opening of the breaker.

'7. A circuit breaker comprising fixed and movable contacts, an angularly movable element for controlling the movement of the movable contacts, disconnecting switches associated with said breaker, and a permanently fixed stop engaged by said element when the breaker contacts are closed for preventing the closure of said disconnecting switches when the breaker is attempted to be moved in a direction to close said disconnecting switches.

8. A circuit breaker comprising fixed and movable contacts, an angularly movable element for controlling the movement of the movable contacts, disconnecting switches associated with said breaker, and a permanently fixed stop engaged by said element when the breaker contacts are closed for preventing the closure of said discon necting switches when the breaker is attempted to be moved in a direction to close said disconnecting switches. said element being moved out of the path of said stop upon the opening of the breaker.

9.-A circuit breaker comprising a top casing,

, a lower tank in sealed connection therewith and downwardly removable from the top casing, disconnecting switches within the top casing, a support carried by and within the upper portion of the tank and removably' connected within the tank, insulators containing conductors secured to and passing through said support, said conductors carrying the movable contacts of the disconnecting switches at their upper ends, make and break contacts at the lower ends of said conductors, and operating mechanism within and supported by said support and having a portion extending through and outside said tank for closing and opening said last named contacts, said insulators and operating mechanism being downwardly movable with said tank.

10. A circuit breaker comprising a top casing, a lower tank in sealed connection therewith and downwardly removable from the top casing, disconnecting switches within the top casing, a support carried by and within the upper portion of the tank, insulators containing conductors secured to and passing through said support, said conductors carrying the movable contacts of the disconnecting switches at their upper ends, make and break contacts at the lower ends of said conductors, operating mechanism within and supported by said tank and having a portion extending outside of said tank for closing and opening said last named contacts, a sealed transparent opening in the side of the tank, and an indicator carried by said mechanism within the tank for indicating through said opening the closed or open position of said last named contacts.

11. A casing, a plurality of incoming and a plurality of outgoing conductors within said casing, an insulating central barrier between said incoming and outgoing conductois respectively and supported by the casing, and insulating barriers between the incoming conductors and also between the outgoing conductors removably supported by said central barrier.

12. A casing, a plurality of incoming and a plurality of outgoing conductors within the casing, an insulating central barrier between said incoming and outgoing conductors respectively and supported by the casing, an insulating barrier set on one side of said central barrier having insulating partitions extending between the incoming conductors, an insulating barrier set on the opposite side of said central barrier having insulating partitions extending between the outgoing conductors, and means lor removably supporting said barrier sets respectively by said central barrier for obtaining individual removal of each of said sets from said central barrier.

13. A circuit breaker comprising a top casing, a lower tank in sealed connection therewith and downwardly removable from the top casing, disconnecting switches within the top casing, a support carried by and within the upper portion of the tank and removably connected with the tank, insulators containing conductors secured to and passing through said support, said conductors carrying the movable cont-acts of the disconnecting switches at their upper ends, make and break contacts at the lower ends of said conductors, post insulators secured at their upper ends to the inside top of the top casing for supporting the fixed contacts of the disconnecting switches, and operating means supported by said support for opening and closing the make and break contacts at the lower ends of said conductors.

14. A sealed casing comprising a supporting top portion and a separately downwardly removable lower tank portion having a scaled connection with the top portion, disconnecting switches located within the top portion, said top portion supporting the fixed contacts of said disconnecting switches, a circuit breaker located within and removably supported as a unit on the interior sides of the lower tank portion and carrying the movable contacts of said disconnecting switches, and connecting means carried by the two portions of the casing for raising and lowering the tank portion for engaging and disengaging said disconnecting switches, said connecting means having engagement when the lower tank portion is below the position of the initial engagement of the disconnecting switches and serving to guide the engagement of said switches when the lower tank portion is raised.

16. A sealed casing comprising a supporting top portion and a separately downwardly removable lower t-ank portion having a sealed connection with the top portion, disconnecting switches located within the top portion, said top portion supporting the fixed contacts of said disconnecting switches, a circuit breaker located within and removabiy supported as a unit on the interior sides of the lower tank portion and carrying the movable contacts of said disconnecting switches, and connecting means carried by the two portions of the casing for raising and lowering the tank portion for engaging and disengaging said disconnecting switches, said connecting means having engagement when the lower tank portion is below the position of the initial engagement of the disconnecting switches and serving to guide the engagement of said switches when the lower tank portion is raised and for also holding the two portions together in sealed connection.

EMIL A. ILEMAN.

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