US1757915A - Circuit interrupter - Google Patents

Description

J. B. M NEILL CIRCUIT INTERRUPTER Filed Feb. 21'. 192'! May 6, 1930.

INVENTOR John 5. Mac/V91 [I A'IFTORNEY WITNESSES: #ZV/wr/Guu Patented May 6, 1930 UNITED STATES PATENT OFFICE JOHN B. MACNEILL, OF WILKINSBU'RG, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA CIRCUIT INTERRUPTER Application filed February 21, 1927. Serial No. 169,801. 1

My invention relates to oil-immersed circuit interrupters and particularly to venting devices therefor.

One object of my invention is to provide a circuit interrupter of the oil-immersed type that shall have a vent operated directly by the actuating mechanism of the circuit interrupter.

Another object of my invention is to provide a circuit interrupter of the oil-immersed type that shall have a spring-biased venting device that may be operated either by the actuating mechanism of the circuit interrupter or by excessive gas pressure within the tank.

A further object of my invention is to provide a circuit interrupter with an adjustable, tensioned venting device that may be operate-d by excess gas pressures within the tank, at any predetermined pressure.

During the operation of oil-immersed circuit interrupters, a large amount of gas is generated, which gas must be liberated or vented. In the preferred form of my invention, a vent is disposed in the cover of the circuit interrupter and in direct engagement with the operating mechanism, so that the circuit interrupter is open to ventilation when its contact members are either in their full open position or in their full closed position, but which is closed when the contact members are in an intermediate position. The intermediate position corresponds to the position of the contact members when the arc is interrupted.

In the accompanying drawings:

The single figure is a view, partially in elevation and partially in section, of a circuit interrupter embodying my invention.

My invention comprises, in general, a circuit interrupter 1 having a venting means 2 that is actuated in accordance with the position of portions of the circuit-interrupteroperating mechanism 3.

The venting means 2 comprises a housing 4 that is secured, by suitable bolts 5, to a cover 6. Within the housing 4 is disposed a coil spring 8 that bears downwardly against a plunger 9.. for maintaining the latter normally in its downward or lower position. A projection 11 on the housing 4 engages a circumferential groove 13 in the plunger 9 to limit the upward and downward plunger movement. The groove 13 functions also, in combination with a port 14, and a port 19, as an air duct or passageway, under conditions hereinafter described.

The interior of the plunger 9 is preferably hollow, as indicated at 15, and is connected by ports 16 and 17 with ports 18 and 19 respectively, in the housing 4.

A set screw 21 is disposed in the lower end of the plunger 9 for engagement with a boss 22, constituting a part of an arm 23 that is rigidly fastened to a rotatable movable shaft 24 by a cap member 25, clamping bolts 26 and 27 and a key 28.

The rotatable shaft 24 extends externally of the cover 6 and has rigidly attached thereto, on its outer end, a crank arm 29 that is operated by an actuating element (not shown) through a pull rod 31 cooperating with a pin 32.

A link 33 is hingedly connected to the arm 23 by a pin 34, the other end of the link being pivotally supported upon a rocker bar 35 by a pin 36. The rocker bar 35 is supported, near its center, by a pin 37 which is mounted in a support 38, that projects inwardly from the cover The opposite end of the rocker bar 35 1s hlngedly connected, by a pin 39, to the center of an operating arm 41, one end of 'which is hingedly attached, by a pin 42, to a movable support 43, and the other end of whiclg supports a member 44 by means of a pin The member 44 is employed to operate conducting contact-bridging members (not shown) through lift-rods 46, which depend therefrom. The conducting contact-bridging members, the contact elements and the lift rods are immersed in oil (not shown) that is disposed within a tank 47 suspended from the cover 6.

Assuming the circuit interrupter to be in its closed position, as shown in the drawing, upon the release of the latching mechanism (not shown) the pull rod 31 is depressed, thereby imparting a'clockwise turning movement to the shaft 24 and the arm 23. The movement of the arm 23 causes the lever mechanism within the circuit interrupter 1 to move the member 44 downwardly, thereby causing the contact members (not shown) to separate. When this movement is started, the interior of the tank 47 is in communication with the atmosphere through the ports 16, 18 the space 15, the ports 17 19 as well as through the ports 14 and 19 and the groove 13. However, as soon as the boss 22 engages the set screw 21', the plunger 9 is moved up'- wardly against the compressive force of the spring 8, thereby causing the relative positions of the several ports to so shift as to interrupt communication between the interior of the tank and the atmosphere. The plunger 9 may move ahead, and independently, of

.the boss 22 if the pressure within the inter plunger 9 andthe tank 4L7. The groove 13 remains in communication with the port 19 and consequently communication between the interior 15 of the plunger 9 and the atmosphere is completed" through the port 17, the groove 13' and the port 19.-

It willthus be seen that the interior of the circuit interrupter 1 is in communication with the atmosphere at the beginning and at the completion of the circuit-opening operation but that it is shutoff from the air at the time when the arc is extinguished. This prevents the throwing, of oil from the circuit interrupter at the moment of maximum excitation thereof, alth'ough permitting the ventilation of the circuit interrupter before the forming and after the quenching of the electrical arc.

During. the closing, movement of the actuating. mechanism (not shown), the pull rod 31 isdrawn upwardly, thereby depressing the arm 23 and the boss 22, during which operation, the spring. 8 expands and forces the plunger 9 downwardly until the upper shoulder formed by the groove 13 engages the projection 11, whereupon the parts are in the relative positions shown in the drawing. The foregoing cycle of operations may be continuedindefinitely. V

It will thus be seen that I haveprovided a circuit interrupter tank that is in communication with the atmosphere before and after the quenching of an electrical arc, but that is closedto' the atmosphere at the time of maximum gas generation in order that oil may not be splashed from thetank.

By reason of the venting of the tank immediately after the quenching of the are, excessive pressures within the circuit interrupter are relieved and the gases generated are permitted to escape into the atmosphere.

I do not wish to be restricted to the specific connections or arrangement of parts herein set forth, as various modifications thereof maybe efl'ected without departing from the spirit and scope of my invention. I desire, therefore, that only such limitations shall be imposedas are indicated in the appended claims.

I claim as my invention:

1. In a circuit interrupter, an operating mechanism, a tank and a normally open venting device mounted in the walls of said tank and a cam on the said operating mechanism for operatingthe said venting device.

2. In a circuit interrupter, an operating mechanism, a tank and a venting device thereon normally open tothe atmosphere and means actuated by said operating mechanism for closing said venting device only while the circuit interrupter is moving between its-open and closed positions.

3. In a circuit interrupter, an operating mechanism, a tank, a venting device normally open to the atmosphere associated therewith and means operated by the operating mecha nism during its travel for closing said venting device.-

4. In a circuit interrupter, a tank, operating mechanism mounted therein, a venting device associated therewith, the venting device having a plurality of passageways for comcomplete and interrupt certain of the pass sageways during the travel of said operating mechanism.

5. In a circuit interrupter, a tank, operating mechanism mounted therein, a venting device associated therewith, the venting device having. passageways communicating between the interior of the tank and the atmosphere when in either of its extreme positions, the passageways being obstructed when the venting device is in an intermediate position, and means constituting a portion of the operating mechanism for actuating the venting device during the travel of the actuating mechanism.

6. In a circuit interrupter, a plurality of contact members, a tank, a venting device for said tank that is normally in communication with the atmosphere andmechanical means for closing said venting device in accordance with the positions of said contact members.

7. In a circuit interrupter, an operating mechanism, a venting device, and a tank normally in communication with the atmosphere through the said venting device that is closed either by the pressure of the gases'within the tank or by the operating mechanism when the circuit interrupter is operated.

8. In a circuit interrupter, a tank, operating mechanism mounted therein, a venting device associated therewith, a variable biasing spring co-operating with the said venting device adapted to permit the escape of the gases therefrom at a predetermined pressure, and an arm on the operating mechanism adapted to actuate the venting device when the pressure within the tank has not reached the said predetermined amount.

9. In a circuit-interrupting device, a plurality of contact members, a tank, a venting structure for the tank normally in open position, and mechanically operated means for closing the venting device during the separation of the contact members.

10. The combination, in a circuit interrupter having separable contact members immersed in a liquid contained in a tank, of a venting device cooperating with the tank normally in open position, and mechanically 0perated means for closing the venting device during the separation of the contact members.

11. The combination, in a circuit interrupter having separable contact members immersed in a liquid contained in a tank and an operating mechanism therefor, of a venting device on the tank that is actuated to closed position by the operating mechanism during the separation of the said contact members.

12. In combination with a venting device for a chamber including a plunger, a variable biasing member and a plurality of orifices, of an operating arm having a cam member thereon adapted to cooperate with the plunger to cause its operation.

In testimony whereof, I have hereunto subscribed my name this 11th day of February,

JOHN B. MAoNEILL.

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