US2150564A - Circuit breaker - Google Patents

Description

March 14, 1939.

R. N.. ROWE CIRCUIT BREAKER Filed sept. 28, 1935 In L il 5...... ...Tf-riff?.

INVENTOR ATTORNEY Patented Mar. 14, 1939 PATENT OFFICE CIRCUIT BREAKER,

Raymond N. Rowe, Plainville, Conn., assignor to The Trumbull Electric Manufacturing Company, Plainville, Conn.,

necticut a corporation of Con- Application September 28, 1935, Serial No. 42,595

1 Claim.

This invention relates to a heavy duty switch or circuit breaker and has for one object to increase the efliciency of such constructions.

Another object is to provide an enclosed arc chamber for a conventional type of quick break or snap action switch or circuit breaker.

Another object is to provide a novel type magnetic blow-out device for extinguishing an arc that may be formed on opening the switch.

l0 The invention contemplates the employment of a moving magnetic field for dispersing the arc which tends to form.

Referring to the drawing Fig. 1 is a. side elevation of one embodiment of this invention with parts broken away.

i Fig. 2 is a section of a portion of this device on the line 2--2 of Fig. 1.

Fig. 3 is a section on the line 3--3 of Fig. 2.

The snap action may be of any suitable type. Fig. 4 is a view of a split washer.

One electrode or switch contact member in this invention is the shaft III preferably of nonmagnetic material which is conductive, such as copper or brass.

The movable switch contact member I I is slidable radially of the shaft I0 and its contact member III' for engagement and disengagement with the surface of the contact I0. 0n opening the A switch by movement of the contact member II away from the contact I0', an arc may occur in the space I2 between the electrodes and under this invention a new type of magnetic blow-out is provided for any such arc.

The current passing through this switch is connected at the terminal I3 and thence passes through the U shaped thermostatic member, shown in dotted lines because such is not a part of this nvention, the current @passing up one leg and down the other of the U shaped thermo- 4`0 static element, from whence it passes through the flexible connection or pigtail- I5 secured to one end of the movable switch member Il. The switch member II is adapted to slide within a guide bearing I6 formed in the metal housing surrounding the space in which any arc may occur.

A conductor I1 is spirally wound around one end 'of the shaft I0 and a similar conductor I8 wound around the other end of 'the same shaft III, these coils being connqected to the same shaft member Ill or in parallel, their opposite ends being connected to the other terminal I9 of the switch. The coils being in parallel and wound in the same direction assist one another in directing the electromagnetic field between the coils so that the flux is substantially parallel to the cylindrical surface I0.

The metal housing 20, around the contact yIII and the arcing space I2, is likewise of non-magnetic material as is the switch part II. Holes 5 2I are drilled and tapped in this ring for the purpose of receiving screws 22 which hold the coils and their housings in position. Contiguous the sides of the ring 2|! are washers 23 of insulating material which is adapted to withstand the high l0 temperature from close proximity of an arc, such insulating washers being of mica or some phenolic condensation product or asbestos or other suitable material.

In order to distribute the flux density sub- 15 stantially uniformly radially and circumferentially around the contact I0', split washers 2l and 25 of magnetic material are located between the coils I1 and I8 and the insulatingwashers 23. On the opposite side of the coils I1 and I8 20 are arranged insulating washers 26 and 21 to safeguard the insulation of each of the coils I1 and I8.

Surrounding each of thesecoils is a housing 28 and 29 of molded or other insulating material 25 clamped in place by screws 22 as shown in Figs.

2 and 3.

The actuating mechanism for the movable switch part II includes a handle member 30 pivoted as indicated for moving the spring 3l each 30 side of its pivot in producing a quick make and break toggle movement for the switch member I I. On closing the switch II by moving the handle 30 to the right, the switch member contacts with the stationary contact member III'. Should the 35 thermostatic element I4 be bent to the left in Fig. 1 and release the lever 32, the springs 33 being heavier than the springs 3| will cause the switch member II to be snapped open without the handle 30 moving. Manual movement of 40 the-handle 30 to the open circuit position indicated may then press down the lever 32 and reset it under the thermostatic latch.

The coils I1 and I8 are of insulated wire wound so that opposite poles are on opposite sides of 45 the arc space, in other words, so that the split steel washers 24 and 25 are of opposite polarity.

It has been found that the efliciency of this construction has been increased by providing the shaft I0 with a silver alloy contact portion I0' and by either providing the movable contact member II with a sim'lar contact portion or by making the entire body of contact member II of a suitable alloy which is preferably of the silver type.

switch. shown in the drawing, to be capable of breaking approximately 5000 amperes at 440 volts with this single pole arrangement illustrated.

I claim:

An electrical switch including a central Bubstantially cylindrical core of non-magnetic and conductive material, two blow-out coils located on either end of said core, washers of magnetic core, said coils being in electrical circuit with said electrodes, whereby the uniform magnetic field and the cyspiral configuration about said core, and substantially air-tight housing means enclosing said space between said coils, whereby said arc will be more readily extinguished.

RAYMOND N. ROWE.

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