US1535835A - Electric switch - Google Patents

Description

J. D. HILLIA'RD ELECTRIC SWITCH Filed Nov. 2o, 1922 z sheets-sheet 1 Inventor vdsk-nrw D. Hilliawc;

if His Attorhe5- April 28, 1925.

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Illlll//llllllll J. D. HILLIARD 1,535'835 ELECTRIC A SWITCH Filed Nov. 20, 1922 2 Sheets-Sheet 2 Fi .2..

l: E 'O' Inventor xiZDMilliavci b5 His Attorvwe.

Patented Apr. 28, 1925.

vUNITED STATES PATENT OFFICE. I

JOHN D. HILLIARD, OF SCHENECTADY, NEW YORK, ASSIGNOR GENERAL ELECTIt-IC COMPANY, A CORPORATION OF NEW YORK.

lEmaocrnrc SWITCH.

Application led November 20, 1922. Serial No. 601,956.

To all whom 'it may concern:

Be it known that I, JOHN D. HILLIARD, a citizen of the United States, residing at Schenectady, in the county of Schenectady, v 5

State of New York, have invented certain new and useful Improvements in Electric Switches, of which the following is a speciication.

My invention relates to electric switches, and especially to means for accelerating the openingof such'switches, and for preventing their accidental closure by pressure generated within the switch tank upon separation of the switch contacts.

My invention is particularly useful in connection with switches operated under high pressure by an operating 'rod movable in- 'wardly through the tank wall -to separate the switch contacts. lIn the operation of such switches, difficulty has been encoun` tered by reason of piston action of the operating rod tending to force it outwardly and thus to accidentally close the contacts immediately after they have opened.

It is, therefore, a principal object of my invention to provide an improved means for utilizing the internal pressure of the switch to hold the switch open until the arc incident to separation of the contacts has been extinguished and normal pressure within lthe tank has been restored.

It is a further object to provide means by which the pressure within the switch tank below the oil line may be utilized to accelerate the opening movement of the switch.v

Other objects and advantages will appear as my invention is considered in connection with the accompanying drawings in which Fig. 1 illustrates my invention as appliedv to a single pole switch, and in which Fig. 2 shows it as applied to a modified form of switch.

Referring now to Fig. 1, there is shown a supporting frame 1, attached to the support 2, andl forming a part of the tank cover 3 which is provided with` apertures for receiving the insulating bushings 4 and the contact operating rod 5. The tank 6 is provided with an insulating lining 7 and is adapted .to contain an insulating liquid 8. The bushings 4 are designed to support the stationary electrodes 9 and are held in place by the clamping rings 10. The contact operating rod 5 which enters thetank 6 through a packed'busliing 11 is adapted to support a movable bridging contact 12 which engages -the stationary contact members 9 to operate the switch.

'.lhe operating means not shown but which may be of any suita le type, such as that shown in Letters Patent No. 942,491 to Emmet & Hewlett, dated December 7, 1909 for example) is connected to the link l 13, motion being transmitted to the operating rod 14 through the toggle 15-16 and the operating lever 14.

A cylinder 17 is attached to the tank 6, registering apertures in each being provided to form a communicating passage 18 which 1s protected by an insulating bushing 19. A hydraulically packed piston 20 is adapted to operate in the cylinder 17 its downward movement being limited by the stud 21. A rod 22 is pivoted at 23 to one end of the bell crank lever 24 and is guided in the piston casing by the spider 25.

Fig. 2 shows a switch of the explosion chamber type, the frame, tank and operating mechanism of which is similar to that .shown vin Fig. 1. An explosion chamber casing 26 is attached to the stationary contact stud 27 an extension of which forms a guide 28' for a piston 29 adapted to move inside the explosion chamber casing 26. rlfhe piston is adapted to support contact lingers 30 which engage in the closed position of the switch shown with a movable contact stud 31. Electrical connection between the explosion chamber casing 26 and the piston 29 ismaintained by a flexible lead 32. The inner side walls of the piston and the bottom of the explosion chamber casing are protected by an insulating lining 33. The movable contact stud enters the explosion chamber through the insulating bushing 34.

A rocker arm is pivoted to the explosion chamber 26 at 37 and is actuated by the pin 38 in the piston 29, transmitting motion of the piston 29 to a connecting member 39 which may be made in the form of a rod of insulating material or of metal rods connected to an insulator 39.. The connecting member 39 is adapted to engage a pin 23 in the bell crank 24 to complete the connection between the piston 29 and the' follows; The 4link 13 is moved to the left,

by 'any suitable operating means, to break the toggle 1.5-16 and permit downward movement ofy the operating rod which disengages the movable electrode 12 from thev contact fingers 9. Simultaneously with the downward movement of the operating rod 5,

the rod 22 is raisedV parting contact with the piston 20. Upon separation of the switch contacts an .arc is drawn inv the liquid which vaporizes ordisassociates a part of the liquid ambient, the arc stream Vthereby suddenly generating a pressure within the` switch tank. This pressure is transmitted through the liquid to the piston 20 which is forced against the end of the rod 22 thereby serving to accelerate the opening movement of thel switch, the movable contacts of which are cooperatively associated with the rod 22 through bell crank lever 24, the toggle 15--16, the-operating lever 14 and the operating rod 5. Pressure will exist within the ytank until the arc is ruptured and during thisl time reclosure of the switch due to piston action on the operating rod 5 will be prevented by reason of the force exerted on the toggle m'ember '16 through the retarding rod 22.

After the arc has been ruptured, normal pressure in the tank will be restored 'by` leakage and the switch may be reclosed, the piston 20 being returned to the position shown by downward movement of the rod 22.

Operation under load from the closed position o'f'the switch shown in Fig. 2 is as follows: Manual or automatic tripping of the operating means permits the breaking of the toggle 15-16, the bell crank 24 moving in a counterclockwise direction. The operating rod 5 will fall to cause disengagement of the movable electrodes 31 from the contact lingers 30.l An arc is drawn in the liquid which will cause the vaporization and dissociation of part of the liquid ambient the arc stream. A pressure will be suddenly generated in the liquid in the explosion chamber which will produce upward movement of the piston 29 and the contact fingers 30 to accelerate the relative movement between the Contact fingers 30 and the movable contact 31. lfVhen the current to be interrupted is of sufficient magnitude the pressure will be generated quickly enough so the upward movement of the piston wil cause the connecting member 39 to overtake the pin 23 in the lll crank 24 inv its downward'movement, thereby pro-v ducing further 'acceleration of the movable contacts 31.- In any case, however, pressure will be exerted upon the piston 29 until-the arc has been extinguished so that reclosure of the contacts is therebyprevented.

My invention may bev embodied in other forms than that shown and described, and I therefore do not Awish to be lrestricted to the precise construction shown, but intend to cover by the appended claims changes invention.

What I claim Aas new and desire to secure electrodes, and a device responsive to presl sure within vsaid -tank to prevent reclosure of said electrodes, said -electrodes being movable independently of said device.

4and modifications within the scope of my 2.'A switching apparatus comprising la tank, contacts separable withinl said tank to break a circuit wherebyan arc is Jformed, means for operating said electrodes,and a device operated by pressurerwithin said'tank sol to assist in separating said .electrodes and -I- prevent their reclosure, said electrodes being movable independently of said device.

3. In a switching apparatus, a tank containinga liquid, electrodes separable within said liquid to break a circuit whereby an arc is formed and pressure is created with- '.in 'said tank, means for operatingsaid electrodes, a device responsive to pressure within said tank to assistl in separatingsaid electrodes and prevent their reclosure, and a lost motion connection betwen said operating means and said device.

4. In a switching appara-tus,atank containing a liquid, electrodes separable within said liquid tobreak a circuit whereby an arc is formed and pressure is created within said tank, means for operating said electrodes, a receptacle in communication -Wit-h said tank, and a pistonwithinsaid receptacle responsive to pressure Within said tank to assist `in opening said electrodes and prevent their reclosure, said electrodes being movable independently of said' piston.

5. In a switching apparatus, a tank containing a liquid, electrodes separable within said liquid to break a circuit whereby an arc is formed andA pressure is created within said tank, means for operating -said electrodes, a casing in communication with said tank beneath the surface of said liquid, a piston within said casing responsive to pressure within said tank to assist in opening saidelectrodes and preventl their reclosure, and a lost motion connection between said piston and said operating means whereby said electrodes, maybe operated independently of said piston.

6. In a switching apparatus, a tank conand Vmeans for transmitting a thrust from taining an insulating llquid, electrodes relsaid piston to said operating means, said atively movable in said liquid to'make and latter means permitting -the operation of 10 break a circuit, means for operating said said contacts independently of said piston.

5 electrodes, a oylinder having a piston there- In witness whereof, I have hereunto setv in and having' a Huid connection with said my hand this 17th day of November, 1922. tank below the level of the liquid therein JOHN D. HILLIARD.

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