US2462753A - Circuit breaker - Google Patents

Description

Feb. 22, 1949. w. D. KYLE, JR., ETAL 2,452,753

CIRCUIT BREAKER Filed Sept. 18; 1943 3 Sheets-Sheet 1 INVENTORS. Z Mam/u .0 Km" (/2.

Feb; 1949. w. D. KYLE, JR, ETAL i} 5 C IRCUI T BREAKER Filed Sept; 18, 1943 3 Sheets-Sheet 2 e e a Feb. 1949 CIRCUIT BREAKER William D. file, Jr., Milwaukee, and Anthony Van Ryan, South Milwaukee, Wis., aaalznors to Line Material Company, a corporation oi Delaware Application September 18, 1943, Serial No. 502,856

1 Claim. 1 This invention relates to circuit breakers. Various attempts have been made to use circuit breakers in distribution system where fuses are also used. These attempts have not proven wholly satisfactory for circuit breakers as ordinarily made will not coordinate with the fuses, and in addition to this the circuit breakers as ordinarily made are too expensive as compared with the cost of the fuse devices.

Objects of this invention are to provide a circuit breaker which has a time'current characteristic corresponding to that of the ordinary type of fuse devices used on distribution systems so that the circuit breaker can be installed in such systems and will coordinate properly with the fuses used in other portions of the system, and a further object is to provide a circuit breaker which although having the time current characteristic of fuses nevertheless is economical to construct.

In greater detail, objects of this invention are to provide a circuit breaker in which it is not necessary to use an insulating housing but in which a metal can or housing which is filled with oil is provided which is completed by an insulating cover or cap, all of the exposed parts of the apparatus being electrically dead at all times except for two terminal members which are carried by the cap and project through the cap, the can being free from any holes or apertures or bushings therethrough and being open only at the top to thereby guard against loss of oil.

Further objects are to provide a circuit breaker in which all parts of the circuit breaker are carried from an insulating cap, the construction being such that the circuit breaker may be lifted from the can if desired for inspection or repair without removing the can from its mounting.

Further objects are to provide a circuit breaker which though it has the time current characteristics of a fuse device, which characteristics are secured through the use of a condition responsive or overload device provided with time delay means-nevertheless is so made that it has substantially instantaneous response to a severe over,- load independently of the action of the time delay means.

Further objects are to provide a circuit breaker which has automatic means and manual means either. of which is efiective to open the circuit breaker with a quick motion, in which the same manual'means which is used to open the circuit breaker is also used as a resetting meansand is so related to other portions of the circuit breaker that the circuit breaker can operate-automatical- 1y independently of such manual resetting means.

thereby allowing the circuit breaker to open automatically although the manual resetting means may be in operation to. reset the circuit breaker and although the manual means may be held in circuit breaker closed position.

Further objects are to provide a circuit breaker in which the automatic action of the circuit while it is being reset, nevertheless no mechanical shock is transmitted to the manual resetting means, thereby protecting the operator in the event the fault still persists while resetting is being attempted.

A further object is to provide a circuit breaker in which no blow is struck the manual means when the manual means is used to open the circuit breaker, thereby protecting the operator against any mechanical shock when he is operating the manual means to open the circuit breaker.

Further objects are to so relate the manual resetting and manual operating means to the remaining portion of the circuit breaker that such manual means will act as an indicating means and indicate whether the circuit breaker is open or closed.

' Further objects are to provide a circuit breaker in which an arcing chamber is provided in a very simple manner to predtermlne the zone in which chamber that it protects other portions of the circuit breaker, the circuit breaker being suspended from the upper insulating cover and being spaced from the bottom of the can, the arcing chamber being freely open at its sides and lower portion and, as stated, spaced above the bottom of the can so that any debric or dislodged particles may drop freely to the bottom of the can out of the zone of either the stationary or movable contacts.

Further objects are to provide a circuit breaker which is so made that it may be adjusted to secure different time current characteristics.

Further objects are to provide a circuit breaker having the above enumerated charatceristics in which the arcing chamber, the stationary contacts, and the automatic tripping means are rigidly connected and rigidly brace each other from the cap or cover of the circuit breaker, and in which the automatic tripping means is readily removable or replaceable without disturbing other portions of the circuit breaker, thereby providing a construction in which automatic tripping means may be readily interchanged to thus adapt the circuit breaker to the requirements of difierent systems in which it may be installed.

Embodiments of the invention are shown in the accompanying drawings, in which:

Figure 1 is a vertical sectional view through the circuit breaker, such view corresponding to a section on the line I--I of Figure 2.

Figure 2 is a sectional view through the circuit breaker on the line 2-2 of Figure 1.

Figure 3 is a fragmentary sectional view on the line 3-3 of Figure l with parts broken away.

Figure 4 is a view of the time delay mechanism and the switch mechanism and associated parts removed from the remainder of the circuit breaker and showing in full lines an intermediate position that the parts assume when the circuit breaker is tripped by an overload.

Figure 5 is a view corresponding to Figure 4 showing the final position of the parts following portion I formed of insulating material. All active portions of the circuit breaker are suspended or carried from or by this cap. The cap I serves as a cover for the metal tank 2 which contains oil and may be filled to approximately the level indicated by the reference character 3. The metal tank 2 has no openings through its bottom or sides through which oil might leak and is open only at its upper portion and is preferably pro vided with a beaded upper edge 4 which tightly bears against a ring like gasket 5 to thus securely seal the tank at its upper end.

A plurality of bolts 6 having threaded upper ends are provided and extend upwardly through apertures in the cap or cover member I as shown in Figure 1 and are provided with wing nuts 1 adapted to be clamped against upstanding bosses 8 formed integrally with the cap or cover member I. Preferably the wing nuts are provided with downwardly flanged lower portions as indicated at 9 to overhang the upper ends of the bosses 8, suitable gaskets being provided as indicated in the drawing. The tank is provided with an integral or unitary, outwardly extending bracket II] which may be secured to any suitable support, such as a pole or cross-arm.

From the description thus far given it is apparent that the cover or cap I may be removed from the tank when the wing nuts 'I are removed and the circuit breaker may be bodily lifted from the tank without requiring any draining of the oil from the tank. It may thus be inspected or repaired and may be replaced and the wing nuts again tightened.

The insulating cap or cover member I is provided with a pair of integral upstanding hollow bosses II which support the high tension terminal members I2. These high tension terminal members are provided with downwardly flanged skirt like portions I3 which overhang the upper portion of the bosses II, suitable gaskets being provided between the terminal members and the tops of the bosses I I in accordance with the usual practice. Heavily insulated conductors indicated by the side walls I6 of the arcing chamber.

generally at I4 and I5 extend. downwardly from the terminal members.

- An arcing chamber is provided and is formed of insulating side members in the form of elongated flat plates I6 and a, transverse upper portion II preferably formed integral with the side members I5. Stationary contacts I8 are mounted within the arcing chamber adjacent opposite ends thereof and are clamped in place by means of nuts I9 carried by threaded studs 29 integral with posts or spacers 2I whose upper ends are secured as shown in Figure 2 within downwardly extending hollow bosses 22 formed integrally with the cover or cap I, the upper ends of the posts or spacers 2i being provided with polygonal-shaped spaced flanges embedded in a low melting point metal which fills the hollow bosses 22 and secures such posts 2I rigidly thereto.

If desired, the inner. cavity formed in the bosses 22 may be left rough or sanded in accordance with the usual practice. I

The movable contacts are indicated by the reference character 23 and are secured to channelshaped members 24 pivoted on pins 25 carried The channel like members 24 are provided with elongated overlapping portions on opposite sides thereof which are equipped with slots 26 within which a, pin 21 carried by a rectangularly shaped insulating slide bar 28 is adapted to operate. It is apparent that when the slide bar 28 is forced downwardly in a manner hereinafter to appear, the movable contacts 23 engage the stationary contacts I8. The movable contacts are joined by means of a flexible connector 29. It is apparent also that when the slide bar or reciprocating bar 28 is moved upwardly, the movable contacts 23 will be rocked downwardly away from the stationary contacts I8 until they are ar rested by engaging insulating spacer sleeves 30 supported by pins 3| carried by the side walls I6 of the arcing chamber. The slide bar 28, as will be seen most clearly from Figure 2, is guided by means of a channel-shaped guide plate 32 mounted between the side walls I6 of the arcing chamber and carried thereby.

It is preferable to line the interior of the metal tank or can 2 with insulating sheet material such as fiber indicated by the reference character 2'.

A rock shaft 33 is carried in bearings 34 and 35 and extends outwardly beyond one side of the upper cap or cover I. The bearings are suitably grooved and have polygonal flanges as indicated and are secured within suitably apertured portions formed in the cap I by means of low melting point metal. Preferably the inner surfaces of the cavities surrounding the bearings 34 and 35 are sanded or roughened in accordance with the usual practice. 'The bearing members 34 and 35 are respectively provided with downwardly and laterally extending lugs 36 and 37.

The outer end of the rock shaft is provided with a manipulating member or eyeleted handle 38 which is rigidly secured thereto. The shaft also carries a sleeve 39 which is provided with a flange 40, the sleeve and flange being notched as indicated at 4|. The sleeve 39 is rigidly secured to the shaft. A spring 42 loosely surrounds the sleeve 39 and bears at one end against the lug 36 and at the other end against a set screw 43 which secures the sleeve to the shaft. The spring tends to rotate the shaft in a direction to move the handle downwardly. It is, however, a relatively light spring for a purpose hereinafter to appear. A second sleeve 44 is loosely mounted 8 on the shaft and is provided with lever members or outwardly extending arms 48 which are rigid with the sleeve 44. g

Main toggle link mechanism is interposed between the lever means 45 and the slide rod 28 and comprises an upper link 48 formed of insulating material and a lower channel-shaped metal link 48. The upper link 48 is pivoted to the lever means 45 at its upper end bymeans of the pin 41 and is pivoted at its lower end between the side walls of the lower channel-shaped toggle link member 48 by means of the pin 49. This lower link 48 has downwardly extending ends which are pivotally connected to the upper end of the slide rod 28 by means of the .transverse pin 68. Tension springs 51 extend between the pin 58 and the ears or lugs 36 and 31, as shown most clearly in Figure 2, and constantly urge the,slide rod 28 upwardly. A light spring 52 tends to straighten out the toggle formed 01' the links 48 and 48.

it is to be noted from reference to Figure 1 that the insulating link 46 is provided with a laterally extending foot portion 53 for a purpose hereinafter to appear.

The circuit breaker is shown in closed position in Figure 1 and in such position it is to be noted that the centers of the pins 41 and 49 lie just to the-left of a line joining the center of the pin 58 with the center of the rock shaft 33 and thus it will be seen that the toggle formed of the links 46 and 48 is in a position just past dead center and the toggle formed of the lever means 45 and the link 46 is also in a position just past dead center. The transverse flange of the link 48 bears against the right-hand side of the link 46 as viewed in Figure 1 and constitutes a stop for the toggle formed of the links 46 and 48. Thesleeve 44 is provided with a projecting lug 54, see Figures 1 and 2, which engages the stationary lug 31 and thus constitutes a stop for the toggle formed of the lever means 45 and the link 46.

It is to be noted that the sleeve 44, which is loose on the rock shaft 33, is also provided with a lug 55 which fits within the notch 4|. This lug constitutes the operating lug for rotating the sleeve 44 during resetting in a manner hereinafter described.

Condition responsive means, such as overload tripping means, may be employed for automatically opening the circuit breaker. This condition responsive or overload tripping means comprises a solenoid 56 wound on an insulating tubular sleeve 51. Within the tubular sleeve a plunger 58 of magnetic material is positioned. This plungerhas a reduced upper end providing a shoulder on which the lower end of a light spring 59 bears. The upper end of the spring 59 bears against a closure cap 68 of non-magnetic material which is flanged and seats against a shoulder formed in the upper portion of the tube 51. It is to be noted from reference to Figures 1, 3, 4 and 5 that the overload tripping device is provided with magnetic strap metal 6| which practically surrounds the solenoid 56, that is to say, it extends on opposite sides and across the upper and lower portions of the solenoid. It may be formed in two or. more pieces as indicated in the drawings if desired.

This metal strap member 8| constitutes the outer magnetic frame or yoke portion of the solenoid. It is apertured to allow the tube 51 to extend through its bottom portion and is provided with an. upper bevelled aperture 62. A lever 63 is pivoted intermediate its ends on a pin 84 carried by the spaced arms of a non-magnetic metal 6 1 member secured to the upper face of the yoke 6|. The lever 83 is L-shaped and preferably formed of non-magnetic material. One arm of the lever overhangs the upper end of the solenoid and pivotally supports a disk like member 66 formed of magnetic material and having bevelled 'like face 69 and with a lower tongue portion 18 arranged in proximity to the laterally projecting foot 53 of the insulating link 46. The cam 68 is so shaped that during closing motion of the circuit breaker the foot 53 of the lever 46 moves along in close proximity to the cam 69. This allows the trip-out device to trip the circuit breaker prior to completion of the closing of the circuit breaker so that just as soon as the movable contacts engage the stationary contacts the circuit breaker will trip out if an overload exists. Thus it will be seen that the circuit breaker is trip free.

The overload tripping means is connected in series with the circuit breaker. For example, one terminal of the solenoid 56 is detachably connected to the lead M by means of a detachable connector 11 and the other terminal of the solenoid indicated at .12 in Figure 3 is connected to one ofthe stationary contacts la. The other of the stationary contacts 18 is connected to the lead 15, thus placing the solenoid 56 in series in the circuit.

The magnetic plunger 58 is retained against passing outwardly through the lower end of the tube 51 in any suitable manner as by means of the split pin 13, see Figure 1. The split pin is removable and plungers of difierent diameters may be interchanged to vary the time current characteristic of the overload tripping .means. The tube 51 is left open at its bottom and any debris or other material that might be produced as a result of wear is free to drop directly downwardly from the tube, thus avoiding sticking or wedging of the plunger. It is to be noted that the member 65 is provided with a lug 65, shown in Figures'l and 3 and omitted in Figures 4 and 5 for clearness, detachabl y attached to a post 19 secured to the cover I and that the yoke 6| of the solenoid is removably connected by means of screws 14, see Figures 3, 4 and 5, to insulating brackets 15 supported from one of the side walls l6 of the arcing chamber. Thus the overload tripping means as well as the time delay means constituting a unitary part thereof may be removed as a unit by detaching it from the brackets 15 and from the lug 19 and detaching the terminals of the solenoid 56 and, thereafter, another overload tripping device with time delay means may be easily substituted to give a different characteristic to the circuit breaker so that the circuit breaker may be readily adjusted or adapted to fit the particular characteristics that may be required for any particular portion of a distribution system.

The operation of the apparatus is as follows: Assuming that the circuit breaker is closed and the parts are in the position shown in Figure 1,

when an overload of reasonable magnitude occurs, the plunger 58 starts upwardly within the tube 51, its upwar d motion bein retarded by the 011 within the tube, the automatic tripping means being submerged below the oil level in the tank 2.

The magnetic plunger 58 will travel upwardly, the oil passing between the outer face of the plunger and the inner surface of the tube 51. As the plunger 58 ascends, the magnetic flux through the solenoid will increase to a point where there is sufilcient pull on the magnetic member 66 to draw the member downwardly and thus rock the lever 63 in a counterclockwise direction. This will force the foot 53 of the insulating link 46 to the right as viewed in Figure 1 and will break the lower toggle formed of the links 48 and 48. The springs will suddenly complete the collapse of the toggle and raise the slide bar 28 and will rock the movable contacts 23 downwardly with a quick motion to their dotted line position shown in Figure 2 where they are arrested and will thus rupture the circuit below the oil level and within the arcing chamber, thus quickly extinguishing any are. v

After the circuit breaker has been automatically tripped, the handle 38 will occupy the position shown in dot and dash lines in Figure 5 and thus will act as an indicator showing that the circuit breaker has been opened, the handle having moved from its normal approximately horio zontal position shown in Figure 1-to its indicating position shown in Figure 5. The spring 42 urges the handle towards indicating position. It is a 3 light sprin and cannot overcome the efiect of the springs 5| which hold the toggle link mechanism in a slightly over center position when the circuit breaker is in closed position.

During automatic operation of the circuit breaker, the lower toggle mechanism formed of the links 46- and 48 instantaneously occupies or passes through the position shown in Figure 4.

of the links 46 and 48 to the position shown in Figure 5, the pin 49 passing slightly past dead center,

When a very heavy overload occurs, such as that produced by short circuit for instance, the magnetic member 66 will be immediately drawn downwardly irrespective of any movement of the plunger 58 as the flux through the solenoid even before the plunger 58 has moved is sufiicient to pull the member 66 downwardly.

When it isdesired to reset the circuit breaker,

the operator engages the eyelet of the handle, preferably with a switch stick as the circuit breaker is primarily intended for high tension distribution systems. The operator merely pushes directly upwardly on the switch stick and rocks the handle from its dot and dash line position shown in Figure 5 to its uppermost position shown in dot and dash lines in Figure 1. The rocking of the handle rocks the rock shaft 33 and consequently rocks the sleeve 39 which is rigid with the handle and rock shaft. The face of the notch 4| in the flanged sleeve 39 to the left of the lug 55 engages the lug 55 and consequently rocks the sleeve 44 and the lever means back to the position shown in Figure 1, it being noted that the lower toggle means, consisting of the links 46 and 48, see Figure 5 for instance, has the center of the pivot pin 48 slightly to the left of a line joining the pivot points 41 and and consequently the lower toggle acts as a rigid member. When the lever means 45 has been rocked to its final position as shown in Figure 1, it will be seen that the pivot pin 4'! is slightly past dead center and thus the upper toggle formed of the link 46 and lever means 45 is locked. It is to be noted that the movable contacts 23 are resilient and allow a certain amount of yield.

The operator then allows the handle 38 to descend to its normal approximately horizontal position shown in Figure 1, the spring 42, see Fizure 2, as well as the weight of the handle assisting in this rocking motion. The right-hand shoulder of the notch 4| in the flanged sleeve 39 comes to rest against the lug and thus retains the handle in its normal position showin that the circuit breaker is closed.

When it is desired to open the circuit breaker manually, the operator engages the switch stick with the handle 38 and rocks the handle 38 from its normal approximately horizontal position shown in Figure 1 to its lowermost position shown in Figure 5. During this downward rocking motion, the lug 55, and consequently the lever means 45, is rocked past dead center and the spring means 5| suddenly causes the lever means 45 to rock to the position shown in Figure 5 and thus quickly raises the slide bar 28, see Figure 2, thus opening the circuit breaker.

It is to be noted that the screw 43 which secures the sleeve 39 to the rock shaft 33, see Figure 2, actsas a stop contacting the stationary lug 36 and limiting the downward motion of the handle, see Figure 5.

The width of the notch 4| and of the lug 55 are so related that when the circuit breaker is being manually opened, no blow is imparted to the handle and consequently no mechanical shock is caused the operator. Also it is to be noted that on automatic operation even though the operator may be moving the handle towards resetting position, nevertheless no mechanical shock is-transmitted to the handle and consequently the operator is protected against mechanical shock both during automatic action in the event he is resetting the circuit breaker and during manual operation. Further than this it is to be noted that although the handle may be held in circuit breaker closed position, or even in its extreme or uppermost position, nevertheless automatic operation of the circuit breaker can take place if the fault still persists as the lower toggle link mechanism formed of the links .6 and 48 is broken by the automatic overload tripping means,

The rate at which the plunger 58 will be drawn upwardly into the solenoid 56 for any given current value is determined by the viscosity of the oil and the relative values of the internal diameter of the tube 51 and the external diameter of the plunger 58. The value of the current at which the plunger 58 will start upwardly is determined by the number of ampere turns in the 'coil 56 and also by the lowermost or initial position of the plunger 58. A certain amount of adjustment may be secured by means of the construction shown in Figure 6, which adjustment determines the initial position of the plunger and thereby determines the value of the current circulating in the winding, which will cause the plunger to start moving upwardly in the tube.

The construction in the form of the invention shown in Figure 6 may include the insulating tube 57' and the plunger 58' which correspond respectively to the tube 51 and the plunger 58 of Figure 1. An adjusting screw 16 of non-mag-v netic material is threaded through a non-magnetic bracket 11 secured by non-magnetic screws 78 to the lower portion of the tube 51'. If desired a lock nut may be provided for the screw -76. Adjusting the screw I6 will determine the lowest point from' which the plunger 58 starts its upward travel and consequently will determine the overload value at. which the automatic operation of the plunger 58 starts, thus altering the time current characteristics. The lower end of the tube 51' is left open. The bracket 11 is merely of spider like construction and does not close the lower end of the tube. Any debris that may be formed as a result of wear for instance can, therefore, drop freely from the tube and avoid 'wedging or sticking of the plunger. In addition to this, as previously described, the combined overload device and time delay means is readily replaced by other combined overload and time delay means so that the combined overload and time delay means having the particular characteristics required for any given portion of the distribution system may be most easily installed to secure the exact time current characteristics desired.

Any desired type of movable and stationary contacts can be employed. In the form shown in Figure 2 for instance a relatively extensive area of contact is secured between the stationary contacts l8 and the movable contacts 23. In the form of the invention shown in Figure 7 the movable contacts 23 may have substantially a line contact with the stationary contacts 18.

It will be seen that not only is the plunger shown in the form of the invention of Figure 1 readily removable, but also the plunger shown in the construction of Figure 6 is removable as it is a simple matter to remove the screws I8 and thereafter remove the spider or bracket 17 and thus allow the plunger to be readily removed. In this manner in either form of the invention different plungers can be substituted to secure diiferent time current characteristics.

It is to be noted that the arcing chamber confines the arc to a certain predetermined limited zone and that this arcing chamber is freely opened at its'sides and bottom, thus insuring free circulation of the 011 during arcing and also insuring the dropping downwardly clear of any active portion of the circuit breaker of any debris or dislodged particles.

Further it will be seen that it is a very simple matter to remove the wing nuts 7 and thereafter lift the circuit breaker bodily from the can 2 for inspection or repair without removing the can from the pole or cross arm or other support and without removing the oil from the can.

It-will be seen further that the condition of the circuit breaker can be readily ascertained by the lineman by noting the position of the handle ll and ii the circuit breaker has been automatically tripped, it may be most easily reset.

It will be seen further that the arcing chamber and the stationary and moveable contacts constitute a unitary construction and that this unitary construction is braced by means of the readily removable unitary construction of tripping means and time delay means, both of the unitary constructions being firmly suspended from the coverof the tank and together forming a very rigid construction.

It will be seen further that by proper selection of the number of turns, the position of the magnetic plunger and the relative diameter 0! the plunger and internal diameter of the tube through which it slides, any desired time current characteristic may be secured and thus the circuit breaker may be coordinated with any desired fuse device.

Although this invention has been described in considerable detail, it is to be understood that such description is intended as illustrative rather than limiting, as the invention may be variously embodied and is to be interpreted as claimed.

We claim: 7

A circuit breaker comprising switch means, manually operable means for opening and closing said switch means, normally extended toggle link mechanism operatively connecting said manually operable means and said switch means, means for normally holding said toggle link mechanism extended and against collapse, spring means tending to collapse said toggle link mechanism, an

energizing winding in the form of a solenoid, a

fluid retarded plunger adapted to be drawn inwardly of said winding, a magnetic member movable axially of said winding when the magnetic flux passing through said winding directly to said member exceeds a predetermined value, a partition located within said tube between said plunger and said magnetic member anddividlng said tube into separate compartments, and means operated by said magnetic member for initiating the collapse of said toggle link mechanism.

WILLIAM D. KYLE, JR. ANTHONY VAN RYAN.

REFERENCES CITED The following references are of record in the Number Name Date 772,914 Badeau --Oct. 25, 1904 818,495 Warren Apr. 24, 1906 1,177,948 Haskins Apr. 4, 1918 1,194,132 Brown Aug. 8, 1916 1,289,656 Cheney Dec. 31, 1918 1,330,094 Simon Feb. 10, 1920 1,399,499 Krantz Dec. 6, 1921 1,621,369 Hilliard Mar. 15, 1927 1,767,479 Roller June 24, 1930 1,960,208 Hammerly May 22, 1934 1,974,428 Mayer Sept. 25, 1934 2,072,932 Wilckens Mar. 9, 1937 FOREIGN PATENTS Number Country Date 23,525 Great Britain Oct. 11, 1910 38,477 Norway Dec. 3, 1923 342,143 Germany 1.- Oct. 18, 192i

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