US1573179A - Electric switch - Google Patents

Description

Feb. 16 192e.- 1,573,179

J. N. MAHONEY ELECTRI C SWITCH Filed July 28. 1921 2 Sheets-Sheet 1 2 Sheets-Sheet 2 J 4 f 4 4 4 a. WW/ "34m/ll mw m Feb. 16 1926.

J. N. MAHONEY ELECTRIC SWITCH Filed July 28 Patented Feb." l16, 1926.

-` UNITED STATES PATENT oEFlcE.

JOSEPH N. MAHONEY, OF BROOKLYN, NEW YORK, AAASSIGNOR, BY MESNE ASSIGTN- MENTS, TO CONDIT. ELECTRICAL MANUFACTURING CORPORATION, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS. Y i

Y ELECTRIC SWITCH.v

Application led July 28, 1921. Serial No. 488,150.

To all 'whom z't may concern.'

yBe it known that I, J osEPH N. MAHONEY, a citizen of the United States, residing at Brooklyn. in the county. of Kings and State of New York. have invented an Improvement in Electric Switches, of which the following lis a specification.

This invention relates to electric switches adapted to interrupt current of considerable magnitude.

When a circuit is interrupted under load in oil a considerable amount of energy is liberated suddenly, which is made manifest irr severalA ways, one of which is the rapid and usually large increase in gaseous pressure within the switch. The sudden liberation of a large amount of energy results in severe strains to the switch and, in the usual type of switch, may result in its rupture.

An object of this invention is to dissipate gradually energy liberated upon circuit interruption as by utilizing saidI energy to set. in motion relativelyv massive bodies, as bodies of oil in the switch, whereby the energy will be absorbed, by said moving bodies, and circulate'the oil and subsequentlv bring the oil to rest gradually whereby to dissipate the energy oi movement therein and at such a moderaterate that the energy dissipation may be accomplished without undue strain on the switch.

A- further object is to provide a switch having an outer spill receptacle and an -inner oil-receptacle and both adapted to contain oil to substantially the same level; and means arranged to effect the circulation of oil between there'ceptacles; and means arranged automatically to maintain the oil level in said inner receptacle.

A further objectis to effect the introduction of oil to the inner receptacle by the movement of the inner oil receptacle due to circuit interruption.

A further object of the invention is a ynovel method of supporting the inner oil receptacle yieldingly in position.

The switch embodying the invention may comprisea rigidly supported outer or spill receptacle and an inner oil receptacle movably disposed within and spaced from the side wall of said spill receptacle and supported yieldingly in position by a helicalspring disposed on the bottom of the spill receptacle and upon which said inner oil receptacle rests. The inner oil receptacle may be formedlwith a neck which comprises a guide or positioning means for, and is disposed within said helical s ring; and an inwardly-opening Vcheck va ve may .be disposed in the neck and arranged normally to close the neck. Both receptacles are adapted to be filled with oil substantially to the same level.l Upon the interruption of a suiciently heavy current, the inner oil receptacle will be moved downwardlyngainst the spring 'by the resulting increase' of gaseous pressure within the switch, and due to the elevated level in the outer receptacle, and also due to the downward movement of theinner receptacle, the valve will" open to establish communication between the two receptacles and oil will flow into the inner receptacle to restore the oil level therein; and

oil may flow also over the top of and into said inner receptacle from said spill receptacle.

A further object Yof the invention istgenerally to improve the construction and operation of an electric switch.

The broad idea of an inner and an outer receptacle with a valve in the inner receptacle to admit a flow of oil from the outer to the inner receptacle is disclosed in a copending application of George A. Burnham, Serial No. 454,427, filed March 22, 1921; and the broad idea of an oil receptacle supported upon a helical spring is disclosed in another 'copending ap lication of George A. Burnham, Serial o. 463,773, filed April 23, 1921, both applications being assigned to S. B. Condit. A

Fig. 1 is a longitudinal sectional elevation of an oil immersed electric switch embodying the invention.

Fig. 2 is a detail similar to Fig. 1 but with the inner oil receptacle in a depressed position and the valve open to establish fluid communication between the inner and spill receptacles.

Fig. 3 is a detail of a modiied valve and illustrating-'the method of opening it positively. y

Fig. 4 is a detail of theinner oil receptacle illustrating a modiied form of neck.

, type of switch.

Fig. 5 is a detail of the switch frame removed from the oil receptacles and looking upwardly into said frame.

Fig. 6 is a sectional detail along line 6 6 of Fig. 5.

i Fig.l 7 is a sectional elevation of a modlfied form of switch embodyingvthe invention.

Fig. 8 is a detail along line 8 8 of Fi Fig. 9 is a detail along line 9-19 of Fig. 10 is a detail along line 10-10 of Fi 8. n

is here shown the invention is applled to the so-called removable-unit type of oil switch but is not limited to this speciiic The switch includes the switch frame 10 comprising a cover for the spill and inner receptacles hereinafter to be described; the stationary switch-members 11 and movable switch member 12 supported by said frame; and the base 13; and the rods 14 which connect said fra-me and base rigidly', and the frame 10 may be removed by first removing the nuts 14a of sald rods 14. A preferably cylindrical outer or spill re ceptacle, V15 having a more or less semi- -spherical bottom 15n is supported on sald base 13; 'and said base is shaped to receive and form a cradle for said receptacle. "Said spill receptacle is here shown as rigidly supported although 'it may be supported otherwise. Said receptacle ektends upwardly above said base within sald rods and may be received within an outer peripheral lip l0* of lsaidframe; and said frame may be drawn down or seated against the top edge of said spill receptacle. A vent pipe 16 having the usual ballies 16a therein, see Fig. 6, may be secured in lthe top of said frame to establish communication between the expansion chamber A under said frame and above the surface of the oil in the spill receptacle and the inner'receptacle hereinafter to be described. and the atmosphere.

A preferably cylindrical movable inner oil receptacle 18 having the more or less semispherical bottom 18a is disposed within said spill receptacle and is spaced from theside wall thereof by suitable means, as the spacers 19, which may be secured to the inner face of the side wall of the spill receptacle and extended toward the inner receptacle to guide it for vertical movement.

Said frame 10 is formed with a plurality of internal lugs 20 spaced apart to provide Y a plurality of passages 21 therebetween; and said inner receptacle is adapted to be held yieldingly in contact with said lugs by resilient, means hereinafter to be described; and said passages 21 will serve to establish equal gaseous pressures in said inner and spill receptacles and also serve to admit or facilitate the transfer of oil from one to the other receptacle.

The bottom 18' of said inner receptacle 18 may be provided with a neck 25, here shown as integrally formed with the bottom of the receptacle, although it may be otherwise formed, as-indicated at Fig. 4, for instance, wherein the neck 25L is a separable member and is held in place in an aperture in the bottom 18n of the receptacle by the {iange 25" l.

and check nuti26. A oppet valve 27 1s disposed in said neck and is arranged to open mwardly, as shown, and normal y maintain closed the -uid passage throu h the neck and open toadmit ow of oi from said spill into said inner oil receptacle when there is an elevated head of oil in said s ill receptacle and pressure conditions wit in the switch are' favorable for such flow of oil.

A relatively stiff open helical spring 30 extends between the bottom 15 of the spill receptacle and the bottom 18 of the inner receptacle and loosely encircles said neck and serves as a cradle to support said inner receptacle yieldingly in place; and said neck may serve to maintain said spring in position'.

Said spring is adapted preferably to press said inner oil receptacle yieldingly against the lugs 20 of the switch frame with considerable force `whereby to load the receptacle and cause it to be unresponsive to a small and inconsequential pressure rise within the switch but to respond and move downwardly in response to a larger and possibly dangerous pressure rise.

Bothouter and inner receptacles are adapted to be filled with oil to approximately the same level, as indicated in F ig. 1. When the switch is opened under load a relatively high gaseous pressure may be crcated in the expansion chamber A of the switch and the inner receptacle 18 will be forced downward against, and compress,

said spring 30, thereby to increase the volume of the expansion space and reduce the pressure rise and relieve the inner receptacle supporting-Structure from shock.

Oil will be expelled upwardly from the inner receptacle by the circuit-interrupting are into the switch frame and thereby absorb a certain amount of the energy liberated by the arc; and the oil will strike against said frame and have its velocity reduced, thereby to dissipate its energy of movement and thence will fall downward, a portion going back into the inner receptacle and the remainder passing through the passages 21 into the` spill receptacle; and the oil level in the spill receptacle will be raised over that in the inner receptacle. The setting into motion of the inner receptacle will absorb a substantial amount of energy and said receptacle will act asia pistpn to press against the body of oil in the spill receptacle and set the oil therein in motion, resulting in a further absorption of energy. The level of oil 1n the spill rece tacle may be such that oil may flow over t e top of and into the inner receptacle from the spill receptacle thereby restoring, at least partially, 011 expelled froml the inner receptacle on circuit interruption. When the oil level in the spill receptacle is sufficiently greater than the oil level inthe inner receptacle, said valve 27 will be forced open and oil will flow from the spill receptacle through said neck into the bottom of the spill, receptacle, thereby to restore the oil level therein; and said valve may be loaded or unloaded, by obvious means, not shown, to govern the operation of the valve and the rateof flow of oil therethrough., Inasmuel" as the gaseous ressure upon the oil in both receptacles 1s the same, vby reason of the communicating passages 21, the transfer of oil through the neck may take place when there is a re1- ative difference4 in oil level and regardless of the existence of an abnormal gaseous pressure Awithin the switch. Furthermore, the inner receptacle will act to some extent as a piston and operateA forcibly to open said valve 27 by reason of the inertia of the lmass of oil in the spill receptacle and force oil into the inner receptacle. `It will be noted that the switch is so arranged that substantial all of the oil is set in motion and means 1s provided for the circulation of oil from the outer to the inner receptacle whereby to present fresh and cool oil to the action of the circuit-interrupting arc. The skin friction ofthe wall fof the inner receptacle in contact with the oil in the spill receptacle assist-s in absorbing energy; and the t body of oil in the spill receptacle operates as a hydraulic shock-absorber to absorb energy from the moving inner receptacle and assist in gradually bringing it to rest and rendering its return movement more gradual. It will be noted further that by varying the extent of opening of said valve and the area of the passage between the spill receptacle into the inner receptacle, the-.movement of the inner receptae e may be governed by varying the resistance offered to the circulation of oil through said valve and over the top of the inner receptacle. A

In Fig. 3 the stem 27 of the valve 27 is somewhat longer than the sternv of the valve illustrated in Figs. 1 and 2 and said stem is adapted to be moved against the bottom of the spill receptacle by the downward movement of the inner receptacle whereby to effect the positivel opening of the valve.

Said inner receptacle, preferably, is not attached to said helical spring but merely rests removably upon it; and said receptacle, preferably, is not secured permanently in position but may be withdrawn upwardly from the spill receptacle.

Fig. 7 villustrates a. modified form of structure wherein the movement of thel inner oil receptacle el'ects the Imovement of the oil or other energy-absorbing fluid in the spill receptacle and in which fluid communication between the two receptacles is suppressed.

In Fig. 7 the yieldingly-'slupported inner oil receptacle 40 is imperf'orate at the bottom and the upper portion ot' its side wall is movably received within the'annular wall 41 of the switch frame and may be. a relatively tight sliding fit therein so that the friction between the frame and receptacle may be substantial, whereby to absorb and dissipate energy of movement of the receptacle, although it will not be ygreat enough tov restrain the receptacle from movement. A packing ring 42 may be inserted in a groove in said wall 41 to engage the receptacle and prevent fluid communication between said outer and inner receptacles. A separator ring 43 is disposed between the outer and inner receptacles beneath the'oil level in the outer receptacle and is arranged to separate the oil spaces above and ,/b/elow it in the outer receptacle; and said ring may be integral with the outer receptacle, if desired. A packing ring 44 may becarried 'by said ring and enga-ge the side wall of said inner receptacle to prevent fluid leakage along the side wall around said separator ring. although permitting movement of the inner receptacle. controlled by the downwardly-opening check-valves 46, and a fluid passage 47 gov` erned by the adjustable valve stem 48 may be formed through said vring to provide for fluid communication with the fluid spaces above and below said ring. With the arrangement herein illustrated there is no means for fluid communication between the outer and inner receptacles and, consequently, the outer leceptacle may contain a fluid other than oil, as Water, for instance.

The form of struc-ture illustrated in Fig. 7 functions substantially like the structure illustrated in Fig. 1 with the distinction that there is no transfer of fluid from the outer to the inner receptacle by reason of the fluid tight seal between the inner recep-U tacle and switch frame and the absence of the valve. 'hen the inner receptacle is moved downward upon its spring, due to pressure resulting from circuit interruption, fluid is forced upwardly through the passages 47 in the ring -43 into the space above said' ring and compresses the airor other gas above the fluid level therein and energy is thereby absorbed. Vhen the pres- `sure within the inner receptacle due to circuit interruption has been relieved, or partially relieved, the innerl receptacle will be moved upward by the action of its supporting spring and also by the pressure of the compressed gas in the outer receptacle, and

Fluid passages 45` fluidwill flow downward through the pas'- sages 45 in said ring 43, whereby to restore the inner receptacle to its normal position. It is apparent that the invention may beapplied to other embodiments without departing from the spirit thereof.

I claim: 4 1. An electric switch having a fixed spill receptacle, a movable inner oil receptacle,

and means to support said inner receptacle 'yieldingly from the bottom of said spill receptacle.

2,. An electric switch having a fixed spill receptacle, resilient means disposed within `said receptacle at the bottom thereof, and

an inner oil receptacle supported movably upon. said resilient means.

3. An electric switch having a fixed spill receptacle, resilient means disposed within said receptacle at the bottom thereof, and an inner oil receptacle supported removably upon said resilient means.

4. An electric switch having a fixed spill receptacle, a helical spring disposed within said receptacle ,upon the bottom thereof,

Vand an inner oil receptacle supported yieldingly upon said spring.

5. An electric switch having a spill receptacle, a helical spring disposed within said receptacle upon the bottom thereof, and

.an inner oil receptacle supported yieldingly upon said vspring having a neck disposed Within said spring.

6. An electric switch having a spill reccptacle, a helical spring disposed within said receptacle upon the bottom thereof, and

g A 9. An electric switch having a fixed spill receptacle, a movable oil receptacle disposed within said spill receptacle having a valvecontrolled fiuid passage in its bottom, and means disposed about siad passage arranged to support said inner receptacle yieldingly.

10. An electric switch having a spill re-A ceptacle, an oil receptacle disposed within said spill receptacle having its bottom formed with a neck, and a valve in said neck. i

11. An electric switch having a fixed spill receptacle, a movable oil receptacle disposed within said spill receptacle having its bottom formed with a neck, and a valve in said neck.

, ceptacle.

12. An electric switch having a fixed spill receptacle, a movable oil rece tacle disposed within said spill receptacle aving' its bottom formed with a neck, a valve in said neck, and means to support said inner receptacle yieldingly.

13. An electric switch having a fixed spill receptacle, a movable oil receptacle disposed within said spill receptacle having its bottom formed with a neck, a 'valve in said neck, and means to support said inner receptacle yieldingly comprising a helical spring disposed within said spill receptacle upon the bottom thereof upon which said inner oil receptacle is supported.

14.. An electric switch having a spill receptacle, a^ helical spring disposedwithin said receptacle ,upon the bottom thereof, a movable oil receptacle disposed within said spill receptacle upon said spring, the bottom of'sai-:l inner oil receptacle having a neck disposed within said helical spring, and a valve in said neck.

15. An electric switch having a spill receptacle, a helical spring disposed within said receptacle'upon the bottom thereof, a

spill receptacle upon said spring, the bottom of' said inner-oil receptacle having a neck disposed within said helical sprin and a valve in said neck arranged to open 1nto said inner oil receptacle.

16. An electric switch having a fixed spill receptacle adapted to contain oil, a downwardly movable oil receptacle disposed within said spill receptacle, switch members disposed within said inner oil receptacle, said inner oil receptacle having a downwardlydirected passage through its bottom, and an inwardly-opening check valve arranged normally toclose said passage. Y

17. An electric switch having a fixed spill receptacle adapted to contain oil, a movable oil receptacle disposed within said spill receptacle, and means governed by the movement of said inner oil receptacle'to control the-admission of oil to said inner oil re- 18. An electric switch having a fixed spill receptacle adapted to contain oil, a movable oil receptacle disposed within said spill re! ceptacle, and means governed by the movement of said inner oil receptacle to control the admission of oil to said inner oil receptacle from said spill receptacle.

19. An electric switch having a fixed spill receptacle adapted to contain oil, a movable oil receptacle disposed-within said spill re-v ceptacle having a fluid passage through its wall and a valve in said passage arranged positivelyto'be controlled by the movement `of said inner oil receptacle.

' movable oil receptacle disposed within said y 20. An electric switch having a fixed spill receptacle and a movable inner receptacle both adapted to contain oil to substantially the same level, means to support said vinner rece tacle yieldingly in position and means to e ect the circu ation of oil between said receptacles.` v Y 21. An electric switch having a fixed spill receptacle and a yieldingly-supported movable inner receptacle both adapted to contain oil to substantially the same level, and means arranged to effect then transfer of oil from the spill receptacle over the top of and into the inner receptacle.

22. An electric switch having a fixed vspill receptacle and a yieldingly-supported movable inner receptacle, both receptacles adapted to contain oil, a switch frame comprismg a cover for both receptacles having a vent passage kthrough it and means to subject said receptacles to the same gaseous pressure, said means including a passage arranged in communication with both receptables and over the oil level therein.

23. An electric switch having a spill receptacle, a yieldingly-supported movable inner receptacle, both receptacles adapted to contain oil, a switch-frame comprising a cover Vfor both receptacles, said inner receptacle the movement of said receptacle comprising comprising a piston movable to force oil from said spill receptacle into said inner receptacle.

24. An electric switch havinga spill receptacle, a ieldingly-supported movable innerl receptac e, both receptacles adapted vto contain oil, a switch-frame comprising a cover for both receptacles, means to establish fluid communication between said receptacles, said inner receptacle comprisin a yiston movable to e'ect the circulation o oi between said two receptacles.

25. An electric switch having a movable oil receptacle, resilient means arranged to support said receptacle yieldingly, and hydraulic means to governA the movement of said receptacle. Y

26. An 'electric switch having a. movable oil receptacle and hydraulic means to govern 28. An electric switch including an oil' receptacle having its bottom formed with a neck, and a poppet valve disposed in said neck normallyto close the upper end thereof and having a stem extended downwardly 'within and outwardly beyond said neck.

29. An electric switch having a receptacle adapted tc contain oil, a movable oil receptacle, and means governed by the movement of said movable oil receptacle to control the transfer cf oil between said receptacles.

30. An electric switchhaving a receptacle adapted to contain oil, a movable oil receptacle, and means governed by the movement of said movable oil receptacle to control the transfer of oil from said first receptacle to said movable receptacle.

.131. An electric switch having a movable oil receptacle, resilient means arranged to support said. receptacle yieldingly, and hydraulic means including said receptacle as an operative element arranged to govern the movement of said receptac e.

32. An electric switch including separable switch-members and two fluid-containing receptacles, .one of which surrounds said switch-members and is movable with respect to theV other receptacle and is constructed to move and'displace fluid in said other receptacle upon circuit interruption.

In testimony whereof, I have signed my name to this specication.

JOSEPH N. MAHONEY.

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