US2129723A - Circuit breaker - Google Patents

Description

Sept. 13, 1938. J D WOOD 2,129,723

CIRCUIT BREAKER Filed Sept. 29, 1956 5 Sheets-Sheet 1 INVENTOR L/O SE/ VJ. fiooa BY h 6 155 P 13, 1933- J. D. WOOD CIRCUIT BREAKER Filed Sept. 29, 1936 3 Sheets-Sheet 2 Ill/4 \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\g! H IN TOR Jsafi/ .fl aaa KJX M ATTORNEY;

Sept. 13, 1938.. J. D. WOOD CIRCUIT BREAKER Filed Sept 29, 1956 s Sheets-Sheet 3' 0 m u m m 1 K S @MW/M Patented Sept. 13,1938 2,129.723

UNITED STATES PATENT OFFICE CIRCUIT BREAKER Joseph D. Wood, Bethlehem, Pa., assignon to Roller-Smith Company, a corporation of New York Application September 29, 1936, Serial No. 103,085

'1 Claims. (oi. 175-298) This invention relates, to clrcuit'breakers and which respectively cooperate with the main conmore particularly to air circuit breakers of the tacts 2 of the arms I, and auxiliary contacts I cubicle type in which one or more circuit break-- which respectively cooperate with the auxiliary ers and their associated apparatus aremounted contacts 3 of the arms I, Sa d Panel contacts 5 as a unit on a movable irame or truck which is ing mounted on conductors 8 which are secured 5' movable into or out of a. cubicle by which the by suitable brackets 9 to the panel 5. The conbusses and connections are permanently supductors 8 extend to the back of the panel and ported. The truck carries yieldable movable concarry at their free ends yieldable contacts I0 tacts which engage fixed contacts on the cubicle which are pivotally mounted on brackets II se- 0 for connecting the circuit breaker to the busses. cured to extensions I2 oi the conductors 8 and are 10 These connections are automatically broken when normally pressed toward each other by springs I3. the truck is moved from operating position, as for The main contacts 6 are pivoted to brackets I5 purposes of inspection or repair. carried by the conductors 8 and are held in pres- One object of the invention is to provide a cirsure engagement with the main movable contacts cuit breaker assembly of the above type in which 2 by springs I6. The auxiliary contacts 3 are the circuit breaker is automatically tripped when Pivotally mOlmted On their arms I and are p the truck is moved from operating'position and in vided with springs which tend to hold the same in which the circuit breaker cannot be closed except en men wi h t auXiliary Contacts 1 n p when the truck is in operating position or in test mitsthe contacts 3 to wipe a o t ts 1 position. Another object is to provide a circuit during the opening movement of the circuit 20 breaker of the above type having means for guidbreaker. Connection is made to the contacts 2 ing the truck into the proper operating position and 3 of the arms I by flexible conductors 20 and and securing the same in such position. Another trip coils I20 which are connected toconductors object is to provide means for safely guiding from H extending through the panel 5 and carrying the cubicle, without injury to the equipment or sp g contacts 22 w h are p v tally mounted 26 danger to the attendant, the hot gases produced on brackets 23 carried by extensions 24 of the by the arc. Another object is to provide a durable, conductors 2| and are pressed toward each other efilcient and commercially practical device of the y sp s 5- The conductors 2| are secured to type above indicated. Various other objects and the pane 5 by brackets 26.

advantages will be apparent as the nature of the c arm I is Controlled y a pair of levers 3|], 30 invention is more fully disclosed. Y pivoted at 3! between the brackets 4. The ends The invention is capable of application to vari- 0f the leve s 3B a e pivoted to links 32 which are ous purposes and will be understood from the 01- in turn pivoted to a link 33 at 34. The lir 1k33 is lowing description and accompanying drawings p d at t0 the arm From the p t 34 35 disclose a specific embodiment thereof extends a Which is pivoted at to a 35 In the drawings, Fig. lis afront elevation of the link 38 is pivotefi at between the circuit. breaker assembly with the front of the i f 4 and carries a pm 40 at Its lower end cubicle removed, certain parts of the assembly whlch 1S engaged by latch normally being omitted for clarity of the drawings; Figg :training the link 38 in fixed position. The latch is a longitudinal section of the assembly showing 13522? 3 2?: 323 8 eiri n d d t it f m i? 40 the truck in operating position in the cubicle; 43 to h a d b a 5- 8 a M 8 en Fi 3 is a longitudinal section similar to Fig. 2 e g ge y mp p unger o e described. The rod 42 extends across the entire but showing the truck in lntelmedlate or test assembly in insulated sections and carries the 45 position in the cubicle.

\ latch II for each circuit breaker A. Projecting 45 Referring to the a n s. a three-pole Circuit elements 49a are fixed to the rod 42 at the sides breaker ha P0165 is Shown mounted as a of latches 4i and each latch has a pin 4Ib at its unit on a truck B wh c is positioned Within a side projecting into a slot 4Ic formed in each fixed cubicle C. Each pole of circuit breaker A is element Ma. A stop member 45 is secured to the 50 shown as Comprising a movable element or arm levers 30 and engages an adjustable stop 46 to 50 I carrying amain contact 2, andan auxiliary conlimit the closed position of the circuit breaker. tact 3. Each arm I is pivotally mounted at its The usual trip coils are provided to control the lower end between brackets Ffixed to a vertically latch of each contact arm. The levers 30, assopositioned insulating panel 5 supported by the ciated with each of the cireuit'breakers A, are

truck B. The panel 5 carries main contacts 6 connected to a cross-bar 41 having a handle 48 55 which provides manual control for operating all poles of the circuit breakers in unison.

Fig.2 shows the circuit breaker in closed position, the latches 4| of each contact arm engaging the pin 40 to retain the breaker in closed position. In this position, the toggle formed by the levers 3D and the links 32 is slightly over-set. If it be desired to open the breaker manually, the handle is moved from the position shown in Fig. 2 to the position shown in Fig. 3, the upward movement of the handle causing the links 32 to be moved downwardly and move the parts to the open position shown in Fig. 3, the pins 40 being still retained by the latches 4|. If the breaker be opened automatically by the tripping of any one of the latches 4| by the usual overload or voltage trip coils, then such latch releases its pole of the breaker and its opening m'ovement causes its pin 4|) to engage the inclined edge 4|d of the element 4|a. forcing it downwardly and thereby turning shaft 42. This causes each of the remaining poles to be tripped by the elements 4|a forcing the pins 4|b of the other latches downwardly. In this opening action, the handle 48 remains in the position shown in Fig. 2 and the spring pressure tending to open the breaker swings the contact arms in a counter-clockwise direction with reefrence to Fig. 2 to the open position. In order to reclose the breaker under this condition, the handle 48 must first be raised to bring the parts in the position shown in Fig. 3, after which the handle can be depressed to close the breaker. It will be appreciated that during this closing movement, the tripping of any one of the latches 4| will cause the breaker to open and cause the parts to move to the trip-free position even though the handle '48 be held in the lower closing position. In order to reclose the breaker the handle must again be raised to bring the parts to the position shown in Fig. 3.

While a particular type of circuit breaker has been described, it is to be understood that the invention is not limited thereto but that any form of circuit breaker may be substituted therefor.

The panel 5 is carried by the truck frame having wheels 50 which permit the frame and associated mechanism to be moved as a unit. These wheels 5|] are guided in the cubicle C by channels 5| carried by the fixed frame 52 of the cubicle and the channels are recessed, as at 53, to receive and guide the wheels and thereby position the truck.

The cubicle frame has an insulating panel 52 mounted at the rear, through which pass fixed contact members 55 and 56 which are supported respectively by brackets 51 and 58 which are fixed to the panel 52'. The contact members extend within the cubicle in positions to be engaged by the spring contacts l0 and 22 respectively. The contact members 55 and 56 also extend outwardly at the back of the cubicle where they are adapted to be connected to the usual busses (not shown). An auxiliary contact member 59 is also carried by the panel 52 and engages a spring contact 55 which is carried by a conductor 5| mounted on the panel 5. The auxiliary contact member 59 extends within the cubicle substantially beyond the contact members55 and 56 for the purpose to be described and various similar additional control contacts may be provided according to particular requirements. The portions of the contact members 55 and 56 within the cubicle are housed within insulating shields 62 and 63.

The trip plunger 44 is carried on a shaft 65 which is slidably mounted within a bracket 65 secured to the panel 5 and which carries at its lower end a fork 51 in which a roller 68 is journaled. A

pin Ill carried by the fork 51 extends through elongated slots II in the bracket 55 to control the vertical movement of the plunger 44. A spring 12 normally holds the assembly in its lower position. The wheel 68 engages a track 13 which is secured to the frame 52 of the cubicle and is provided with raised sections 14 and I5 and with depressed sections 15 and 11. The raised sections 14 and 15 hold the wheel 58 and the plunger 44 in a raised position with the plunger 44 engaging the free end 43 of the latch 4| and'operating the same to release the pin 40 to open the breaker. When the wheel 68 engages either of the depressed sections 15 or 11 the plunger 44 releases the free end 43 of the latch 4| and permits the operation of the circuit breaker to be controlled by the handle 45 or by the trip coil in the usual manner. The depressed section ll of the track is positioned so that the wheel '58 engages the same when the truck is in operating position in the cubicle. The depressed portion 16 is positioned so that the wheel engages the same when the truck is in an intermediate or test position. It will be noted that in these two positions only, can the circuit breaker be closed, as in all other positions where the wheel engages the raised portions 14 and 15 the plunger 44 automatically operates the trip mechanism to trip the circuit breaker.

The contact members 55, 56 and 59 are so arranged that contact is made with the spring con tacts I0, 22 and 60 when the truck is in operating position as shown in Fig. 2. .When the truck is in the intermediate or test position as shown in Fig. 3, the spring contacts 10 and 22 are disengaged from the contact members 55 and 55 but the contact between the contact member 59 and the spring contact 50 remains closed and likewise any other similar control contacts. Thus in this position the circuit breaker main contacts are disconnected from the line, whereas the auxiliary contacts 59 and 6B and similar control contacts remain closed and may be used for test purposes. It is evident that these contacts can be used for various purposes, for example, in the circuit of automatic trip or closing coils of the circuit breaker to permit operation thereof when the truck is in test position.

The sections 14, l5, l6 and ll of the track 13 are connected by inclined cam surfaces 18 so that the trip mechanism is automatically actuated in response to movement of the truck when the wheel 59 rides up on a raised portion. Thus if the breaker truck is in operating position as shown in Fig. 2 and the breaker is closed, the breaker will be automatically opened by any outward movement of the truck before disconnection of the contacts with the various conductors 55 and 56 and protects the latter from arcing effects. When the truck is moved outwardly from test position, the raised portion 14 insures that the breaker will be automatically opened before being removed from the cubicle.

For locking the truck securely in operating position and for forcing it into position, a pair of toggie mechanisms is' yjprovided each comprising links and 8|. The'links 8| are pivoted at B2 to the truck frame. The links 80 are connected to a removable bar 83 which is held in brackets 84 secured to the cubicle frame 52. An operating handle 85 is connected to one of the links to permit manual operation thereof. After the truck has been advanced near the test position as shown in Fig. 3, the bar 83 is inserted to connect the links 90 to the frame 52. Thereafter movement of the handle 85 exerts a force eous discharges.

through the force multiplying links 80 and BI for forcing the truck into operating position. When in this position it is permanently secured by the links 80 and 8| forming a toggle as illustrated in Fig. 2.

Each circuit breaker A is mounted between a pair of shields 90 of insulating material which extend from above to below the arcing contacts so clined shield 93 is mounted across the top of the cubicle at the front portion in a position to form substantially a continuation of the inclined shield 32 to assist in directing the gases to the rear. A vent 94 is formed at the rear of the cubicle near the top and may be connected to a suitable duct (not shown) to conduct the exhaust gases away. A shield 95 may be secured to the frame to direct the gases to the duct 94 and away from the contacts l0. It is to be understood that the various sides of the cubicle are closed and that a removable cover or door 96 closes the front thereof, no louvers in the front being required.

In the opening of a circuit breaker of this type, particularly under heavy currents, the hot gases produced by the arc, unless properly controled, are likely to injure the equipment. The present construction provides means to direct the gases upwardly and rearwardly through the vent 94, and to cool the gases by contact with cool surfaces thereby preventing injury to the apparatus and protecting the front of the cubicle from gas- The baffles 9|, 92, 93 and 95 serve to direct the gases in the manner above indicated and control them until their energy is dissipated.

Although a specific embodiment of the invention has been disclosed, it is evident that it can be applied to various types ofapparatus and that various changes and modifications may be made therein without departing from the scope'of the invention.

I claim:

. 1. The combination of a circuit breaker, a fixed support, a frame carrying said circuit breaker and movable towards and from said support, separable contacts carried by said support and said frame to connect said circuit breaker to an external line, and means located permanently at a fixed distance from the contacts carried by said fixed support and active upon movement of said frame away from said fixed support for tripping said circuit breaker before said frame has moved sufficiently to open said separable contacts.

2. The combination of a circuit breaker, a fixed support, a frame carrying said circuit breaker and movable towards and from said support into operating or test positions, separable contacts carried by said support and said frame-to connect said circuit breaker to an external line, and means located permanently at a fixed distance from the contacts carried by said fixed support and engaging said circuit breaker to prevent closing of said circuit breaker except when said frame is in said operating or test positions. v

3. The combination of a circuit breaker, tripping means therefor, a fixed support, a frame carrying said circuit breaker and movable towards and from, said support into operating or test positions, separable contacts carried by said support and said frame to connect said circuit breaker to an external line, and means located permanently at a fixed distance from the contacts carried by said fixed support for actuating said tripping means and for rendering said actuating means inoperative when the frame is in said operating or test positions.

4. The combination of a circuit breaker. a fixed support, a frame carrying said circuit breaker and movable towards and from said support, separable contacts carried by said support and said frame to connect said circuit breaker to an ex ternal line, tripping means for said circuit breaker comprising a member movable with said frame and a stationary track located permanently at a fixed distance from the contacts carried by said fixed support and cooperating with said member to trip said circuit breaker when the frame is in certain positions with reference to said fixed support.

5. The combination of a circuit breaker; a fixed support, a frame carrying said'circuit breaker and movable towards and from said support, separable contacts carried by said support and said frame to connect said circuit breaker to an ex ternal line, tripping means for said circuit breaker comprising a plunger associated with said frame, and a stationary cam member located permanently at a fixed distance from the contacts carried by said fixed support and cooperating with said plunger to trip said circuit breaker when the frame is in certain positions with reference to said support.

6. The combination of a circuit breaker, a fixed support, a frame carrying said circuit breaker and movable towards and from, said support,

separable contacts carried by said support and said frame to connect said circuit breaker to an external line, tripping means for said circuit breaker comprising a plunger carried by said frame, a roller operatmg said plunger and a stationary track engaging said roller and located permanently ata fixed distance from the contacts carried by said fixed support to actuate said tripping means, said track being formed to release said tripping means when the frame is in certain positions with reference to said support.

'7. The combination of an air circuit breaker, a cubicle enclosing said circuit breaker, insulating shields at the sides of the circuit breaker contacts, a vent from the upper part and rear of said cubicle, a battle located across the front of said shields and supported by said shields and inclined to direct towards said vent the hot gases produced by the arc, and an inclined baille supported on said cubicle above said first named baille and inclined to cooperate therewith to direct towards said vent the hot gases produced by the arc.

JOSEPH D. WOOD.

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