US2076352A

US2076352A - Electric circuit interrupter

Info

Publication number: US2076352A
Application number: US100510A
Authority: US
Inventors: Germain Jacques Marie Saint
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1935-12-23
Filing date: 1936-09-12
Publication date: 1937-04-06
Anticipated expiration: 1954-04-06
Also published as: DE676352C; FR811011A

Description

April 1937- J. M. SAINT GERMAIN 2,076,352

ELECTRIC CIRCUIT INTERRUPTER Filed Sept. 12,. 1936 Inventor:

'Uacques Mar'ie Saint Gevmuin,

Patented Apr. 6, 1937 UNITED STATES PATENT OFFICE f ELECTRIC CIRCUIT INTERRUPTER ration of New York Application September 12, 1936, Serial No. 100,510 In France December 28, 1935 7 Claims.

My invention relates to electric circuit interrupters, more particularly to those of the fluid- Jet type wherein a jet or blast of arc-extinguishing fluid, either gaseous or liquid, is directed into the path of the are formed upon opening of the circuit.

It is often desirable that the type of switch commonly known as a .disconnect switch and usually mounted in overhead position in high voltage transmission lines be adapted to interrupt at full voltage, load currents of appreciable magnitude, the main oil circuit breakers of course being generally relied upon to interrupt short circuit currents and the like. Various arrangements for accomplishing this have been proposed including air jet devices actuated by the operating mechanism of the disconnect switch itself. However, when fairly large currents are to be Y interrupted, the manual operation of this type of switch may be rendered very difllcult, if not impossible, due to the amount of energy required for the efl'ective operation of the air jet device.

A principal object of my invention is the provision of an improved load-break circuit interrupter which can be manually operated without difllculty and which is effective automatically to energize arc extinguishing means.

In accordance with an embodiment of the present invention, electromagnetic means for projecting an arc-extinguishing fluid into the path of the arc is automatically energized in accordance with the initial circuit opening movement. More particularly, the present invention is mainly characterized by the fact that the electromagnetic actuating means, which may comprise an electric motor, a solenoid or other suitable apparatus for placing an arc-extinguishing fluid, such asair for example, under pressure, is energized from the circuit which is to be inter- 0 rupted. For example, in the closed circuit position of the circuit interrupter the electromagnetic fluid actuating means is short circuited by the interrupter contact structure, the circuit opening operation causing said contact structure automatically to connect said electromagnetic means in series with the circuit.

Accordingly, the generation of fluid pressure starts automatically as soon as the circuit opening operation starts and stops automatically as soon as the arc is extinguished. The energy required for the arc interrupting operation is taken from the main circuit and it need not, therefore, be supplied by an auxiliary actuating device, such as by manual operating means or by an inde- 5 pendent source of fluid pressure.

My invention will be more fully set forth in the following description referring to the accompanying drawing, and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

Referring to the drawing, Fig. 1 is an elevational view, partly in section and partly diagrammatic, of a high voltage disconnect switch embodying the present invention, and Figs. 2 and 3 are elevational and plan views, respectively, of another form of high voltage disconnect switch to which the present invention is applied.

The disconnect switch illustrated by Fig. 1 comprises a movable rod contact I mounted and guided, as by suitable supporting structure I, for horizontal reciprocal movement. The disconnect switch also comprises a main base plate 2 which supports through the high voltage insulating members 3 and 4 the movable contact structure |--i The operating means for the movable contact may comprise any suitable apparatus, such as a linkage generally indicated at 5, operatively connected to the movable rod contact through a pin and slot connection indicated at 5, The linkage may be suitably operated by rotation of the insulator 4 through a rack and gear indicated at 4, the movable contact being biased towards the open circuit position by a spring 5.

Also, supported on the base 2 by a high voltage insulating support 6 is the fixed contact structure, generally indicated at 1, coacting with the movable rod contact I. The fixed contact structure comprises in the present instance a pair of spaced contacts 8 and 9 which are engaged and bridged by the rod contact I in the closed circuit position as shown. The aforesaid fixed contacts are mounted with respect to a conducting housing 9' which in the present instance includes a fluid impeller indicated at l0 and an insulating nozzle l I through which the movable rod contact I operates. The nozzle Ii not only forms an exhaust passage for the impeller but also serves as an insulating mounting for the contact 8.

The impeller I0 is suitably driven by an electric motor M, the terminals ofwhich are connected respectively to the contacts8 and 9. Accordingly, in the closed circuit position shown the rod contact I, which bridges the contacts 8 and 9, short circuits the motor M.

The terminals of the disconnect switch indicated at l2 and [2' are electrically connected to the movable contact I and the fixed contact 9 respectively. It will, therefore, be apparent that in the closed circuit position the circuit between the terminals i2 and i2 is direct through the rod contact l and fixed contact 9.

The operation of the device for interrupting a power circuit is as follows: In the closed circut position illustrated, the movable rod contact l engages and bridges the fixed contacts 8 and 9, thereby short circuiting and de-energizing the motor M. When the rod contact I is initially moved towards open circuit position by rotation of the insulator t, the separation of contacts l and Q shunt-s the main current through the motor M thereby instantly energizing the same and causing building up of fluid pressure by the impeller it. No are, however, is formed at this stage of'the operation since the circuit is still complete through the motor M, fixed contact d and rod contact i. Accordingly, during the travel of the rod contact i from fixed contact 9 to the exhaust port of the nozzle H where the arc is first formed, the impeller H) is building up fluid pressure so that at the instant the rod contact l leaves the nozzle i l a blast of arc-extinguishing fluid is directed into the path of the arc. The motor, of course, remains energized as long as the circuit is uninterrupted, and immediately upon interruption of the arc the motor is automatically de-energized.

Although in the present instance an air jet is utilized for interrupting the arc between the contacts l and 8, it should be understood that any suitable arc-extinguishing fluid, either gaseous or liquid, may be employed without departing from the spirit of the present invention;

It should also be understood that the type of impeller indicated at it] is shown merely by way of example and that any suitable means for creating fluid pressure or for compressing a gas may be used, such as a piston or centrifugal compressor-type impeller, etc. For the electrical actuation there may be utilized an electric motor, an electromagnet, a torque motor having a long stroke, etc.

The present invention is, therefore, particularly adapted to manually operated switches or to those having operating means with a comparatively small power output since no greater eiiort is required for opening and closing than in the case of a conventional disconnect switch. Moreover, the intensity of applications of the fluid jet can correspond to the magnitude of the current to be interrupted.

In the modification shown by Figs. 2 and 3, the motion of the movable contact is rotational and the disconnect switch includes two breaks in series, the arc-extinguishing fluid being distributed between these two breaks.

The movable contact arm or carrier I5 comprises a tube which is carried by a central insulator l6 rotatably mounted on the base 2. The fluid projecting means may be suitably supported by the insulator i6 and is generally indicated at ll. The fluid pressure generated at ll directs jets of gas through both ends of the tube l5 to the movable contact structure at H5.

The flxed contact structure is generally similar to that disclosed in Fig. 1 and is carried by the insulators l8 and H9 at I3 and I9, respectively, a single flxed contact being used at one break.

The motor or electromagnetic device at IT is electrically connected to the pair of fixed contacts at the other break in the manner illustrated by Fig. 1 so that on circuit opening movement jets of air are projected into the path of the arcs at the two breaks. As in the preceding instance, the electromagnetic means is automatically de-energized when one of the arcs is interrupted.

It should be understood that the present invention is applicable not only to the above described type of disconnect switch, but generally to all kinds of circuit interrupters wherein it is desired to interrupt the are by one or more jets of a suitable arc-extinguishing fluid, such as an inert gas, air, oil or the like.

It should also be understood that my invention is not limited to specific details of construction and arrangement thereof herein illustrated, and that changes and modifications may occur to one skilled in the art without departing from the spirit of my invention.

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

1. An electric circuit interrupter comprising relatively movable contact structure, means for projecting an arc-extinguishing fluid into the path of the arc formed upon circuit opening movement of said contact structure, and means electrically connecting said means to said contact structure so that said means is short circuited in the closed circuit position of said contact structure and is automatically energized in response to initial circuit opening movement of said contact structure.

2. An electric circuit interrupter comprising relatively movable contact structure, means for projecting an arc-extinguishing fluid into the path of the are formed upon circuit opening movement of said contact structure, and means for connecting said fluid projecting means in series with the circuit to be interrupted upon initial circuit opening movement of said contact structure, said contact structure short circuiting said fluid projecting means in the closed circuit position.

3. An electric circuit interrupter comprising relatively movable contact structure, electromagnetic means for projecting an arc-extinguishing fluid into the path of the arc formed upon circuit opening movement of said contact structure, and means for electrically connecting said electromagnetic means with respect to said circuit so that said electromagnetic means is de-energized in the closed circuit position of said contact structure and is automatically energized from the circuit to be interrupted in response to initial circuit opening movement of said contact structure.

4. An electric circuit interrupter comprising relatively movable contact structure including a pair of contacts and a contact relatively movable with respect thereto for bridging said pair of contacts, electromagnetic means for projecting an arc-extinguishing fluid into the path of the are formed upon circuit opening movement of said contact structure, and means electrically connecting said electromagnetic means to said pair of contacts so that said electromagnetic means is de-energized in the bridged closed circuit position of said contacts and is automatically energized from the circuit to be interrupted upon initial circuit opening movement of said contact structure.

5. An electric circuit interrupter comprising a pair of fixed contacts, a contact relatively movable with respect thereto arranged to bridge said contacts in the closed circuit position, electromagnetic means for projecting an arc-extinguishing fluid into the path of the are formed upon circuit opening movement of said movable contact, and means for electrically connecting said electromagnetic means across said flxed contacts so that said electromagnetic means is short circuited and deenergized in the closed circuit position, said electromagnetic means being automatically energized from the circuit to be interrupted 5 when said movable contact is disengaged with respect to one of said contacts and being automatically de-energized when the are formed between said movable contact and the other of said flxed contacts is interrupted by said arc-ex- 10 tinguishing fluid.

6. An electric circuit interrupter comprising relatively movable contact structure, a fluid impeller for projecting an arc-extinguishing fluid into the path of the arc formed upon circuit open- 15 ing movement of said contact structure, and a motor for actuating said impeller electrically connected with respect to said contact structure so as to be short circuited thereby in the closed circuit position and to be automatically energized from the circuit to be interrupted upon initial circuit opening movement or said contact structure.

7. An electric circuit interrupter comprising relatively movable contact structure, electromagnetic means for projecting an arc-extinguishing fluid into the path of the are formed upon circuit opening movement of said contact structure, and means for electrically connecting said electromagnetic means with respect to said circuit so that said electromagnetic means is deeenergized in the normal closed-circuit position of said contact structure and is automatically energized from the circuit to be interrupted in response to a circuit-opening operation for causing separation of said contact structure.

JACQUES MARIE SAINT GERMAIN.