US1181736A - Venting-door for circuit-breaker casings. - Google Patents

Description

F. 5. CASE.

VENTING DOOR FO R CIRCUIT BREAKER CASINGS.

APPUCATiON FILED AUG-I1, 19M.

1, 181 ,736. Patmted May 2, 1910.

WITNESSES! INVENTURIV m\f ,g g g FRANK E. EASE,

yflzzw- WQM H15 ATTU NEY.

25 for insulating the interior of the box.

40 with the switch contacts.

UNITED STATES PATENT OFFICE.

' FRANK E. CASE. OF SCHENECTADY, NEW YORK, ASSIGNOR- TO GENERAL ELECTRIC COMPANY. A CORPORATION OF NEW YORK.

Specification of- Letters Patent.

Patented May 2, 1916.

Application filed August 11, 1914. Serial No. 856.255.

New York. have invented certain new and useful Improvements in Venting-Doors for Circuit-Breaker Casings, of which the following is a specification.

This invention relates to electromagnetic switches for controlling electric circuits,

especially those carrying heavy currents. The invention is applicable to any such device where the breaking of the circuit is "attended by the formation of an are between the switch contacts as they separate. A blow out magnet is usually provided to extinguish the arc and a chute to direct the flame and gases away from the vicinity of the switch mechanism.- It: is also customary to inclose these switches, especially circuit breakers and contactors, in protecting casings. But it is found that in order to successfully open a heavy circuit in a completely closed box, extraordinary precautionshave to be taken The pressure of the gas produced in opening the circuit is liable to divert the current and cause it to jump between points at a considerable distance from the main contacts,

and the object of the present invention is to eliminate this trouble. It has been found that a hinged-door in the casing, closed by pressure of the'gas in the box is sufficient to move it, so that it does not wholly remove the trouble. I have therefore provided a door hinged at the top and having an arm acting as the armature of a coil in series WVhen the current becomes excessive, the door will be pulled open just before the are at the contacts has attained sufiicient magnitude'to cause an increase in gaseous pressure, thereby afi'ording ample opportunity for the arc to be projected through the opening and reducing the tendency for it to take some abnormal course.

In the accompanying drawing, Figure 1 is a cross section of a circuit breaker or concontacts open.

The circuit breaker illustrated 1s a stand- 65' ard form of contactor, having a solenoid 1,

a movable core 2 therefor. a main switch lever 3 hinged at i and pivoted to said core at 5, a' nain contact brush (3 on said lever cooperating with a stationary contact I, a secondary contact 8 cooperating with the contact T and carried on an auxiliary lever 9 pivoted at 10 to the main lever 3 and having a slot 11 to permit its rear end to play past the pivot 5 of the core. a spring 12 bearing on the tail of the lever 9 to give the second ary contacts a yielding and wiping action, an arc chute 13 inclosing the contacts. and a blow out magnet 14. The contactor is inclosed in a box or casing 15 of any suitable construction. In the side of this box adjacent to the arc chute is an opening, closed by a light door 16 hinged at its top so as to open outwardly. An arm 17 on the door extends above the hinge joint and carries an iron piece 18 which acts as an armature for the coil 19 in series with the conductor '20, whose circuit is controlled by the switch con tacts.

the coil 19 it attracts the armaturelS and thereby swings open the door '16. as indicated in dotted lines in Fig. 1. This aiiords an outlet for the flame and gas which follow the breaking of the circuit at the switch contacts, and thus prevents any injurious accumulation of pressure in the box.

In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that the apparatus shown is only illustrative, and that the invention can be carried out by other means.

What I claim as new and desire to secure by'Letters Patent of the United States, is

1. The combination with an electromagnetic switch and a casing inclosing the same, of a door in said casing adjacent the switch contacts. and means controlled by the current flowing through the said switch con-. ,tacts for opening said door.

2. The combination with an electromagnetic switch and a casing inclosing the same, of a door in said casing. and means for automatically opening said door upon an abnormal rise of current.

3. The combination with an electromagnetic switch having a casing inclosing the \Vhen an abnormal current flows through saine ot' a door in said casing, and a series coil for opening said door.

r. The combination with an electromagnetic switch and a casing inciosing the same, of a door in said casing an armature on said door, and a series coil cooperating with said armature to open the door.

5. The combination with an electromagnetic switch and aeasing inciosing the same, of a door in said casing hinged at the top, an armature extending above the hinged joint and a series coil adjacent to said armature.

6. The combination with an electromagnetic switch having an armature, of a casing for said switch having a door adjacent to said switch, and means for opening said door just before a dangerous rise of pressure in said casing due to arcing between the switch QontaCU-z.

T; The combination with an netie switeh and a casing inciosing he of a door in said casing: a coil in selie the contacts of said switch and mean: by the door opened by said (:nii when current through the contacts and rho rises to a point where the innsrruption the circuit at the contacts would come dangerous pressure in the casing.

In witness whereof. I have ilrl'ttiifiw set no in hand this 10th day of August 19H.

FRAX K ii. (A 5K.

'itnesses HELEN ()Rrono. BENJAMIN B. Hui.

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