US1339981A - Circuit-reaker - Google Patents

Description

F. W. ROLLER.

CIRCUIT BREAKERE APPucATmN men MAH. :9. 1917i- UNITED STATES PATENT OFFCE.

FRANK W. ROLLER, OF EAST ORANGE, NEJV JERSEY, ASSIGOR- TO ROLLERSMITH COMPANY, .A COR'EGRATION OF NEW YORK.

CIRCUIT-BREAKER.

Application le. March 19, 1917.

To all whom t may concern Be it known that FRANK 1V. ROLLER, a citizen of the United States, residing at East Orange, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Circuit- Breakers, of which the following is a specification.

This invention particularly relates to circuit breakers for alternating current circuits and is applicable to circuit breakers of various types and form of construction.

Where polyphase motors are used, it is not an uncommon occurrence to accidentally or unintentionally change the order of connection of the phases to the source, or to the transformer supplying a circuit, with the result that the polyphase motors which have previously been operated with one order of connection of the phases, will upon the change being made have their direction of rotation reversed. Such a result is likely to have disastrous consequences as in instances where the motors are used for supplying the power to elevators or hoists and also in cases where the machinery driven by the motor must always be operated in one direction only.

The main object of `my invention is to provide a simple, reliable and compact constructionv which will secure automatic protection against reversal of phase connection inv a polyphase circuit. Another object is to provideprotection against failure of source of' current or no voltage7 in any one or more 'of the phases of the circuit. Another Objectis to provide a circuit breaker of the above type in whichv the automatic control is combined with the circuit breaker directly without the necessity of using relays or other auxiliary current controlling` devices. Other objects and advantages of my invention will be understood from the following description and accompanying` drawings.

Figure 1 is a side elevation of a circuit breaker embodying my invention, certain windings being omitted for clearness, and Fig. 2 is a diagram of connections and illustratingthe controlling windings.

The supporting panel of insulating material carries a` lixedyieldable contact 11 at its upper portion from which connection is Specification of Letters Patent.

Patented May 11, 1920.

serial nu. 155,710.

made to one line of the service circuit controlled. The movable contact lever 12 c0- operates therewith, being pivoted at 13 between side supporting frames 14, which are in turn mounted upon the panel 10. A flexible electrical connection 15 is secured to the lower end of the switch lever 12 and also to the bolt 16 by connection to which the said line of the supply circuit is completed. Between the side frames 11 is pivotally ymounted at 1T an operating lever 18 having a handle 19. The operating lever carries at its inner end a roller 2O which cooperates with a roller 21 carried by the switch lever so that when the handle 19 is pulled downwardly, it will bring the movable switch lever to the closed position shown. in closed position the axis or roller 20 will be slightly below a plane passing through the axis of the pivot 17 and the axis of the roller 21, the adjustable pin 22 impinging against the side frame 14e to prevent movement of the operating parts beyond the position described. In this particular form of construction, the breaker will therefore be forced to open position unless restrained, the force exerted by the yieldable contact 11 and by the leaf springs 23 and the force of gravity tending to move the switch to open position. On the outside of the frame 14 and on the pivot 13 is pivoted a pawl or latch 24:, the outer end of which engages pin 22 and normally holds the breaker in closed position.

Secured to the panel 10 is a toothed laminated member 25 and in the particular form shown has six slots adapted to receive three coils 26, 27 and 28 as shown in Fig.y 2, the three coils being adapted for use, as shown in this instance, for a three phase circuit. rlhese windings or coils are of fine wire of a large number of turns and have one terminal of each coil connected respectively to the three phase circuit, the otherterminals of each coil being connected to a common point 29 giving a Y connection. The coils being displaced angularly as shown in Fig. 2, a shifting magnetic eld is createdv by the three phase currents exciting these windings.

Depending from the side frames 14: are arms 30 between which is mounted a shaft 31 to which is secured an arm 32 carrying at its inner end a laminated sector 33 and which also carries a series of conductors 34 across its face, which conductors are shortcircuited at their ends by the side plates of the sector 33, or by other suitable means, giving a squirrel cage 'form oi: secondary element coperating with the primary element 25 and windings. F iXed to the shaft 3l is an arm 35, the outer end of which is connected by a link 36 to the latch 24 by a pin and slot connection giving a lost motion or hammer blow in releasing the circuit breaker.

teierring to Fig. 2, the source of current is indicated as a primary winding 37 of a three phase transformer, the secondary 3S of which supplies the service circuit 39. In the case of a three phase circuit, the circuit breaker will preferably comprise three switches of the form shown in Fig. l, the movable switch lever l2 of each being rigidly connected, but insulated from each other as indicated at l2 in Fig. 2. A single closing lever and operating handle 19 may be used to simultaneously close all three parts of the triple pole switch.

Assuming the circuit breaker to be in the closed position as shown in Fig. l, the currents exciting the three phase wound element 25 will under normal conditions cause the secondary element 33 to exert a torque in the direction of arrow 40, which will cause the latch 24 to be drawn downwardly and be held in engagement with the pin 22, or permit the latch to fall by gravity to engage the pin 22, holding the breaker closed. Upon failure of voltage in any one or more of the three phase lines, it is evident that a shi-fte ing field would cease to be created by the windings of the primary element 25, which would result in no torque being exerted by the secondary element 33. By reason of the weight o'i this element, it would then move downwardly, turning the shaft 31 in a clockwise direction and by means of the slotted link 36 striking the latch 24 a hammer blow and so causing the latch 24 to release the pin and so permit the circuit breaker to be thrown to its open position.

Also in case of a change in the order of the phases of the circuit supplying the service lines 39 being made, the action of the flux created by primary element 25 will be correspondingly changed and result in a torque being exerted by a secondary element in a direction opposite to that of the ar row v40, causing the element 33 to move downwardly and thereby raise the latch 24 and cause the circuit breaker to be opened under such an abnormal condition. It will thus be seen that the coils 26, 27, 28 are always in circuit when the breaker is closed, and any abnormal condition on the lines which would by any chance cause a change in direction of rotation of motorsl connected to the circuit, would have a corresponding eiiect on the element 33 and cause a protective operation of the circuit breaker to open position.

In some cases the controlling coils 26, 27 and 26 may be connected to the supply lines back ofthe circuit breaker, which would give the same controlling effect. Although in the present instance I have described my invention as applied to and embodied in a triple pole three-phase breaker, yet m invention may be applied to circuits of a dlferent number orn phases and the circuit breaker may have a different number of switches than .the three above described. It is also evident that my invention may be applied t0 switches or circuit breakers of other types or form of construction from that herein shown and various other modifications may be made without departing from the scope ot my invention.

I claim 1 l. The combination with a polyphase circuit of a manually closable switch, a latch biased to lock said switch in closed position, a movable element for controlling said latch, and a rotative polyphase motive device for controlling said element to permit said latch to lock said switch in closed position when the phases of the current of said polyphase circuit are in proper order.

2. The combination with a polyphase circuit of a manually closable switch, a latch biased to lock said switch in closed position, a movable element for controlling said latch, and a rotative polyphase motivel device for causing said element to deliver to said latch a hammer blow for releasing the switch upon a change .in the order of phases of said circuit.

The combination with a polyphase circuit of a manually closable switch, a latch biased to lock said switch in closed position, a movable element for controlling said latch, and a rotative polyphase motive device for controlling said element to permit said latch to lock the switch in closed position when the phases of the current of said polyphase circuit are in proper order and for causing said clement to deliver a hammer blow to said latch .tor releasing the switch upon change in the order of the phases of' said circuit.

4. The combination with a polyphase circuit of a switch, a latch biased to restrain said switch in closed position, a rotative polyphase device comprising a stationary sector having windings thereon functionally related to said circuit, a rotative sector cooperating with said stationary sector and having closed circuit paths for currents induced from said stationary sector, and means for controlling said latch upon movement of said rotative sector.

5, In an automatic polyphase circuit breaker, the combination of an insulating support, a manually closable switch mounted thereon and havingbrackets for supporting the movable element of said switch, a latch biased to lock said switch in Closed position, a rotative .device ycomprising a stationary element mounted on said support and having polypliase windings and a rotatable sector eoperating with said stationary sector, said rotatable sector being supported l0 by said brackets, and means for causing the movement of said rotatable sector to control said latch.

FRANK W. ROLLER.

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