US1072177A

US1072177A - Circuit-breaker for electric circuits.

Info

Publication number: US1072177A
Application number: US195?0604A
Authority: US
Inventors: Frank L Sessions
Original assignee: Jeffrey Manufacturing Co
Current assignee: Jeffrey Manufacturing Co
Publication date: 1913-09-02
Anticipated expiration: 1930-09-02

Description

F. L. SESSIONS.

CIRCUIT BREAKER FOR ELECTRIC CIRCUITS.

APPLICATION FILED FEB.25,1904.

Patented Sept. 2,1913.

3 SHEETS-SHEET 1.

F. L. SESSIONS.

CIRCUIT BREAKER FOB. ELECTRIC CIRGULTS.

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CIRCUIT BREAKER FOR ELECTRIC CIRCUITS.

APPLICATION FILED FEB. 25, 1904. I I 4 Pacented Sept. 2, 1913 3 SHEETS-SHEET 3k aYwK 5:214, 7

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GIMHIT-BBEAKEB B insecu e, usters Specification Letters Mont.

Patented Sept. 2, 1913.

Anghcation'thd mini-y w, 386. 803a 1S0. 195,906.

Ithas, for one of its objects to provide a circuit breaker. in which the arcing occurwithin the mechanism atthe' instant of the final break of the circuit therein is caused to take placebetween carbon contacts after the metallic contacts which are used have been separated, so as to avoid rapid deterioration of .the inetal contacts.

Another. object of my invention is to provide means'for tuning the action of the cirnet. Itis preferably tor-med inte cuit breaking mechanism under an over-load of current on the circuit, whereby the circuit, will not be broken instantaneously, but the said breaking will occur after a predetermined interval-of continuance-of the excess of current.

Figure 1. is a face view of a mechanism embodying my improvements, the face plate of the casing being removed. Fig. 2 1s aview partlyv in face elevation, 'withthe plate removed, and partly in vertical section Fig. 3 is a perspective showing the bracket the casing, the magnetand some of the upper contacts and terminals. Fig. 4'is a perspective showing the contact separatinq rod, the trigger, the tripping rod and ban lever for closing the circuit. Fig. 5 is a central vertical section of the apparatus. Fig. 6 is a cross-section on line 66 of Fig.

Fig. 7 is a horizontal section on the line 77 of Fig. 5. Fi 8 is a vertical section showing the checking or retarding device. Fig. 9 is a section of the spring and spring actuated devices which hold the armature in normal position. Fig. 10 is an end view of the parts. in Fig.9.

In the drawings the apparatus is shown as provided with a casing having the back ovements in Circuit-Break n 18, the top walllS, the bottom 20, the side walls 18", and the front detachable wall or cover 19. said bottom and side walls belng preferably formed of non-magnetic material.

A represents a block of insulating material secured in posltion in the upper. part of the casing. It serves to providefan insulat ing support for certain of theelectric conductors within the casing.

, the upper end. or terminal 22 is a binding postsecured to the underside of the bloc A and? adapted to receive. the conductor through which the current enters the mechanism. 22? indicates the base portion of the said binding post to which Moi the coil of the blow-out magnet 24 is This coil, as a whole, is of the'character-ofa,

spool, with suitableinsulation-between its convolutions.

12 indicates the metallic core of the magal with the back wall 18' and like the sai wall is This core at its forward end is bifurcated, as

' shown at 12, 12.

12", 12 are projections carried b the back piece 18, one arranged at either side of the casing and adapted'to serve as poles for the magnet 24.

The current after pas 'ng through all the convolutions of the coil, travels over the outgoing conductor section 25 to the stationary.

contact plate or brush 2.. This brush or contact late is secured to insulat-in plate A and is formed with the under-s'oping or tapered surface 2.

3" is a binding-post secured to the insulating block A and adapted to receive the conductor through which the current passes from the mechanism. This binding-post has extending inward from it the contact plate or brush 3 having its under edge sloping or tapered as indicated at 3.

4 is a carbon block secured to the under surface of the contact )late 3 and 6 is a carbon block secured to t e under surface of the contact plate 2.

1 indicates as an entirety a switch or mov- 3 of the contact'plates 2, 3 with which they um adapted to engage.

cured in the holder 30 beneath the plates of copper therein and adapted to have its ends "contact with .the lower-most points of the blocks 4 and 5 respectively. These carbon able circuit closing member. This switch preferably consists of two sets of movable contact engaging elements or brushes. -The upper one 30 is formed of a series of laminae 1 or pla es of copper securely fastened together and held by an insulating holder 3O which is secured tothe upper end of the rod 29. The laminae, or layers of copper increase in length downward so as to provide tapering or sloping ends-tor the brush which correspond to the tapered edges 2,

1' is a spring seblocks 5 and 7 .are preferably secured in holders 8 which are pivotally mounted in bearing blocks 8" secured to the opposite ends'of the-spring 8. 8 are springs for holding the carbon holders yieldingly relative to the said spring 8.

26 is a flexible conductor held within the insulated holder 30 and having its ends secured in the carbon holders 8 and immediately adjacent 'to the carbon blocks 5 and 7 It is made of metal which is a good conductor of elec tricity and is adapted to in- .the spring being conipi sure good electrical connection between. the carbon blocks.

The path of the current through the mechanism is as follows: It enters at the binding-post 22 and passes throughthe coil 24 to the stationary contact 2. When the circuit is closed the current passes from the contact plate 2 through the brushes carried by the switch 1 t0.the contact plate 3 and thence through the binding post, 3 to the main.

In order to break thecircuit I provide mechanism for drawing the copper plates or ,laminae'of the brush 30 away from the contacts at 2 and 3 and subsequently separating the contacts 4:, 5 and (i, 7. As stated 5 these brushes are supported at the upper end of the carrier or rod 29. This rod is held and guided by a collar 29 which is socured at 29 to the core 12' of the magnet and extends down between the project-ions 12 thereof.

28 is a spring surrounding the rod-29 and hearing upward against the collar 29 and downward against the r l: 17 29 on the rod, d when the rod is forced upward to cause the circuit within the mechanism to be closed and, being under compression, -is ready to quickly draw or thrust the rod downward when the latter is.

released from; the locking device, to be described. The latter consists of a triggerlike device, indicated by 36, it having -up'- right legs, 36' which are pivoted at .37 to a.

lug 37 on the bottom wall 20 of the casing.

At its upper end this trigger-like device 36 has outwardl straddle the ower s uared portion of the rod 29. The upper e ges of these arms 36"' are curved, the curvature being concentric with the axis ofthe pivotal connection at 37.

35 are anti-friction rollers mounted on studs or pins carried by the rod 29. They are adapted to rest and roll upon the aforesaid curved edges of'the arms 36*.

.38 is a. spring secured at one end 'toan arm 38 on the trigger device 36 and having its other end adapted to rest on the bottom 4 wall 20 of the casing. This springEt'en'ds' projecting arms 36 which 38 the rollers 35 on the rod 29 escape from the arms 36 and the rod is ciluickl'y thrust downward by the action oft e spring 28. The release ofthe rod 29 from the trigger is effected electromagnetically.

9 represents the, armature of the magnet. I

It is supported by a bifurcated carrierpivoted at 10 and 11 to the casing.

At 9 there is an apertureinto' which is loosely fitted a rod 14. I

14. is a pin in the rod Magainst which the armature can bear, and the aperture 9" is of suchshape that its own swinging movement and thatof the rod 14 will be compensated for. The rod 14 has a' loop .14", the ends of which are pivoted at 14 to the aforesaid arms 36".: If the lower end of the armature is forced inward it will through the rod 14, and the pin 14 push the trigger device 36 back so as to release the rod 29. Such action of the. armature occurs when the current passing through the above described path becomes too strong for then the magnet 24 and its core 12 are energized to such an extent asto powerfully draw the armature inward. i

At 15 there is a push button, which, through rod 15, enables the operator, when ever he desires, to break the circuit, for by pushing inward upon these parts he thrusts the rod 14 inward, which in turn pushes back. the trigger device at 36 and allows the rod 25) to drop. The push button 15 is not positively connected to the interior releasing mechanism, and merely contacts at its inner end with the outer-end of the rod 14 as is shown in Fig. 7. As a result ofthis construction, the rod 14: and the parts at tached to it are free to move independently of the push button, and it is not therefore posslbleffor the operator to hold the con tacts in closed position by means of the push button if the current should exceed theamountfor which the parts are adjusted. To enable the operator to restore the contact again, after the circuit has been automatically or otherwise opened, the hand lever at 31 is provided, the arm 32 of which, slotted at 33, engages with pins or with rollers at 34 on the contact rod 29. By swing ing the lever in the proper direction the rod 29 will be pushed up until the rollers 35 get to points above and rest'upon -the lock arms 86". The under edges of these arms are so shaped as to be cam-like and when the roll ers 85 strike said under edges they force the trigger-like device backward until they pass the points of the arms. By having the up vper edges curved in the way described, that is concentric with the axis at 3'2, I attain important ends. The rollers or pins on the rod 29 cannot act to throw the trigger in ward, they in fact, when a ward, forcing the trigger, i anything, out ward toward its active position; but at the same time, when power is applied to the trigger it rolls with the least possible amount of friction under the rollers 35, and consequently there is a greater assurance that the desired action of circuit breaking shall occur than is incident to other mechanisms with which I am acquainted.

'lhe armature 9 is normally held separate from the magnet core at 12 by means of a spring actuated plunger 13. and the compression spring 13' which controls it zit-rearranged in a casing or cylinder 13 having a longitudinal slot 13 in which a lug 13 on the piston 18 operates, the engagement of this lug with the inner end wall of the slot" tends to limit the inward movement of the plunger.

13 is a pin carried by the plunger 13. It extends through the cylinder and is adapted to engage with a downwardly projecting lip or ear 9 on the armature 9. The cylinder 13- has a projecting arm or lug 13 which is secured at 13 to the under-plate of one of the core arms 12 and holds the cylinder in position.

It is frequently desirable, especially in locomotives for. electric traction work, to employ very heavy currents for a few seconds in starting loads and for such purposes I have provided a time limit device which may be employed with the mechanism above described when desired, it being adapted to be adjusted so as to permit a heavy overload to be carried by the circuit for a sufiicicnt time to start the train. it this overload continues for too great a period of time the circuit breaker will operate to break the ressing down- I This plunger circuit, but if the overdoad does not eontime for the predetermined limit for which the retarding device is adjusted and the our rent through the circuit diminishes, the circult breaker will not be opened,

In the drawings, 40 indicates as an entirety a retarding device of a style preferably for use in connection withthe armature 9 above described. It comprises an'oil cylinder, ll, communicating at its rear-end through the duct 41, with an oil receiving chamber 42, and at its front end through a duct ll with an oil receiving chamber 43. 44 1s a duct connecting the said oil receiving chambers a2 and 453.

4 indicates as an entirety a valve which is adapted to control the flow of oil through the duct 44.

46? is a piston or plunger adapted to. opel ate in the cylinder 41 and 46 is the plunger rod which is pivotally connected at 46 to a downwardly projecting lug 9 arranged at one side of the armature 9.

The cylinder 40 and the oil chambers 42 and 43 may all be formed in a single cast: mg, as shown in Fig, 8.

47 is a lug or projection on 41 which is secured at 48 to the under side of one of the legs 15% of the magnet core 12 and serves'to support the cylinder and the parts connected with it in proper position relative tothe armature 9. 1

4A is a conical recess formed at one end of the duct 44.

The control valve comprises a screw threaded stem or rod 49 which is hollow at its inner end as indicated at 49.

50 is a hollow capor valve head which is screwed on to the inner end of the valve stem 49, At its inner end 50 it is conically tapered to correspond with the recess 44 into which it is adapted tobe adjusted.

50 is a duct leading from the cap 50 and arranged to communicate directly with the duct 44. Within the interior of the said cap or valve head is arranged a spring controlled check valve comprising a ball 51 for which a seat is provided at the inner end of the valve stem 49. 52 is a spring normally pressing the said ball valve against its seat.

58 is a cap fitted to the outer end wall of the oil reservoir 43 and adapted to receive and guide the valve stem 49.

54 is a stufiing box for the cap 53.

49 is a duct leading from the interior of the hollow end of the valve stem 49 and adapted to establish communication between the oil chamber 43 and the interior of the said valve stem.

55 is an index dial or wheel secured to the outer end of the valve stem 49. Its periphery is notched as indicatedat 55.

55 is a spring secured at its inner end to the under side of the oil chamber 48 and arranged to have its outer end engage with the the cylinder is i walls of the notches 55 on the dial 55, so

as to hold'the valve stem in any position into which itmay be adjusted.

The oil is introduced into the cylinder 41 and normally fills the space between the plunger and the inner end of the cylinder, the duct 41 and the oil chamber 42 when the circuit through the mechanism is closed. lVhen an overload on the circuit occurs the magnet 24 tends to draw the lower end of the armature inward as heretofore described. The inward movement of the lower end of the armature is opposed by the oil in the.

retarding device. The inward movement of the plunger 46 tends to force the oil in the, chamber'42 into thechamber, 43, the

adjustment of the conical end of the head 50 and the walls of the recess 44: a.

greater period of time will be required for transmitting-the oil from the chamber 42 to the chamber 43 and for the incident travel of'the plunger 46 in order to force the trigger device 36 vback so as to release "the switch 1.

When the armature 9 of themechanism above described is controlled in its opera tion by means of a retarding device such as the one herein described, it willbe seen that it is possible to so regulate the retarding device as to predetermine the time during which the overload may continue on the circuit. The operation of the retarding device at the time an over-loadv occurs is as follows: The magnet 12 attracts the armature 9, which through the rod 46' exerts an. inward pressure on the plunger 46 tending to force the oil as above described from the chamber 42 to the chamber 43. If the overload continues for a, long enough period of time, or for a period greater than that for which the retarding action of the check valve is adjusted, the trigger device 36 will be forced rearward and the rod 29 will be forced downward under the action of the spring 28. But if the over-load does not occur for such' a predetermined period of time the circuit through the mechanism will not be broken. When it is desired to close the circuit after it has been opened for any reason, the handle 31 is used, and as before described the rod 29 is raiscd'until the trigger device 36 locks the said rod against downward movement. During this upward movement of the rod 29, the spring 38 acts upon the trigger 3G to force the rod 141- outward. The rod 14: serves by means of the pin 14 to transmit the force of the spring 38 to the'armature 9, and to thus aid in pushingfou'tward the lower end of the armature. As thisend of the armature moves outward it draws outward the plunger 46 of the retarding device, this tends to force oil from th chamber {l3 through the duct 49, unseatiii and passing thence intd the chamber 42. Oil may also pass from the chamber 4:3 through the conical space between the valve head- 50 and the recess 44 to the chamber 42. It will be seen that in viewof the relatively lai ger passageway, the power necessary to force the oil from the chamber 43 to the chamber 42 is considerably less than that required for the opposite action.

In order to prevent the arcing which occurs between'the stationary and movable contacts from seriously injuring the closely adjacent metallic parts of the mechanism, I provide to have this arcing take place in insulated chambers or compartments. These compartments are shown at 56-57, Each is a hollow rectangle comprising the bottom insulating plate 58 and two side walls or plates of insulating material 59--59 and. the top plate 60. This rectangle of insulating material is inserted in apertures 61-62 in the side walls- 18"18 of the frame and extends inward surrounding both the metal and the carbon contacts within the mecha nism. -When the switch 1 is thrown down, breaking the circuit, the arcs which occur between the brushes are blown out by the magnetic lines of force passing between the armature 9 and the pole pieces 12"-12 ar-- ranged in the rear of the casing. This blowing out of the arcsby the lines of force insures an increased life of the brushes and the fact that this arcing occurs entirely within an insulated compartment insures that it will have no detrimental effect upon the metallic parts of the mechanism. The walls of the insulatingcompartments, as shown, extend outward beyond the side walls l8"18 of the casing to keep the fiamesy'from the arcs between the. brushes from contacting with said walls.

What I claim is:

1. in a circuit breaker for an electric circuit, the combination of the switch for opening and closing the circuit, means for throwing the switch so as to open the circuit, the anti-friction roller carried by said switch, and a pivoted trigger device having a curved surface concentric -with the pivot of the device arranged to engage with said anti-friction roller .to hold the circuit closed andmcansfor releasing said trigger device, sub-- stantially as set forth.

2. In a circuit breaker for an electric circuit, the combination with the stationary brushes and the movable. briishes of means for controlling the operation of the movable brushes, comprising a spring actuated rod g the valve 51 in valve head 50 i Lorena? having anti-frictionrollers carried thereby and arran ed on opposite sides thereof, and a trigger evice adapted to engage with said rollers to hold the said brushes in contact with each other, substantially as set forth.

8, In a circ s breaker for an electric circuit. the con 'iation with the stationary contacts through which the circuit is closed, of a rectilineally movable rod for controlling the movements of the movable contacts, a spring associated with said rod and adapted to exert pressure thereupon, tending to cause it to open the circuit, anti-friction rollers carried by said rod on opposite sides thereof, a trigger device having arms adapted to engage said rollers to hold the circuit through the mechanism closed, means for projecting trigger arms into the path of travel of the said rollers and means for releasing trigger device, substantially as set forth. I

t, In sire-"it breaker for suits, two contacts, means for h contacts in engagement with cacti electroniagnet having a stationary core, an armature arranged to form a pole piece for the magnet at one side of the contacts and arranged to swing away from the said stationary core to open or completely close an air gap between the core and the armature the said armature being adapted to release said holding means for the contacts, sub stantially as set forth. v

5. in a circuit breaker for an electric circuit, the combination of a switch, means for automatically opening said. switch, locking devices attached to said switch, a trigger adapted to engage said locking devices and hold the switch in its closed position, said trigger being adapted to move to permit the movement oflhe switch from its open to its closed position, an electro-mag'net, a movable armature for said magnet, a retarding device ccTnnected to said armature and adapted to prevent its rapid. movement, and connections between the armature and the trigger whereby movement of the armature toward the magnet will release the trigger, said connections adapted to permit movement of the trigger independently of the armature, substantially as set iorth,

In a circuit breaker an electric circuit, the combination oi a switch, n normally holding the switchin swi n a trigger adapted to engage the locking" device to hold the switch in its closed position, said trigger being. adapted to move out of the path of the locking device when the switch is moved from its open to its closed position, an electro-mag'net, a movable armature for said electro-ma, let, a retarding device connected to sai' arms ture and adapted to prevein rapid. movement, connecting means between the armature and the trigger whereby movement of the armature toward the magnet will release the trigger, said connecting means being adapted to permit movement of the trigger independently of the armature, and a hand-controlled device adapted to engage said connecting means to release the trigger, said hand-controlled device engaging the connecting means independently of the armature, substantially as set forth.

7. In a circuit breaker for an electric circuit, the combination of a switch, automatic means for moving the switch to its open position, a locking device connected to the switch, a trigger adapted to engage the locking device to hold the switch in its closed position, said trigger being adapted to move out of the path of the locking device when the switch is moved from its open to its closed position, a releasing device connected to the trigger, a hand-controlled device adaptcd to engage the releasing device in such a way as tobe capable of moving it only in the direction to release the trigger, an electro-magnct, a movable armature for said magnet, a retarding device connected to the armature and adapted to prevent its rapid movement, said armature engaging said releasing device independently of the engagement of the hand-controlled device in such a way as to be capable of moving; it only in the direction to release the trigger, substantially as setforth. a

8. In a circuit breaker for an electriccircuit, the combination of an electro-mannet having bifurcated core, a stationary switch contact, a movable switch contact, a longitudinally movable rod upon which said movable switch contact is supported, said rod extending between the two prongs of the core, a spring adapted to move the rod to open the switch, a trigger adapted to hold the rod in position with the switch closed, a movable armature mounted adjacent the bifurcated core, and a connection between the armature and the trigger whereby movement of the armature toward the core will release the trigger, substantially as set forth.

In a circuit breaker for an electric circuit, the combination of a stationary switch contact, a movable switch contact, a longi tudinally movable rod upon which the movable switch contact is supported, means for automaticallymoving the rod to open the switch, a trigger adapted to engage the rod to hold the switch in closed position, an electro-magnet having a bifurcated core, the two forks of which are located on opposits sides of the said rod, pole pieces on one side of switch contact and magnetithe cdre will release the trigger and permit In testimony whereof I affix sighs the switch to open, the said poles, core and ture in presence of tWo witness armature forming a part of a maqnetic cir- I cuit which passes through the sx iiitch coni FRANK SES/LONS' 5 teats and serves to blow out electric arcs be- Witnesses:

tween said contacts, substantially as set (J. E, WAXBORN,

' forth. v R. R. DUNLOP.