US2598546A

US2598546A - Electric switch

Info

Publication number: US2598546A
Application number: US52335A
Authority: US
Inventors: Houst Frantisek
Original assignee: Czechoslovak Metal & Engineeri
Current assignee: Czechoslovak Metal & Engineeri; Czechoslovak Metal & Engineering Works
Priority date: 1947-10-09
Filing date: 1948-10-01
Publication date: 1952-05-27
Anticipated expiration: 1969-05-27

Description

y 1952 F. HOUST ELECTRIC SWITCH Filed Oct. 1, 1948 J INVENYPR. Franrisk Houst AT TOR N EY Patented May 27, 1952 .iFrantiseki Houst, -Brunn, Czechoslovakia, :assignor of one-half to Czechoslovak .Metal & Engi- Tneering .Wonks, .National fiorporation, .Prague,

Czechoslovakia Application October 1, l94-8,=Serial"No. 52,335 In 1Czechoslovakia October 9, 1 947 .Thiszinventionzrelates to electric-circuit break- :ers :and, more particularly, to novel means for :quenching :the are :formed when the circuit breakerisnopened under load.

-Inrsuchrcircuit breakers arranged to interrupt 1 heavy currentsor :high voltage circuits, provision must be made to quench the resulting are formed between the relatively movable circuit controlling contacts. .Numerous Wayshavealready been suglgestedrto break up and to cool-the electricarcs thus shortening their duration. This can be achievedeither in a: gaseous medium such as air orrin azliquidsuch "as oil.

In .order to obtain the are quenching effect, electromagnetic forces-actingupon the arcand/or .vthe ,pressureao'fv highlycompressed air and/ or the vpressurelof .the products resulting frm-the decomposition of the .medium surrounding the arc are .utilized.

.Most of l the arrangements .hitherto used have the drawback-that the are is continually passing ithrough the :same .place, thus influencing the cooling medium and its surroundings by increasing their temperature. To overcome ,this .drawbacktconstructional embodiments have been suggested.Wherein-the-fiow of .the quenching medium is directed against movable cellstarrangedin the :shape of a turbine runner wheel .for example,

vwherebythe are is brought .into contact witha steadily renewed, cool and electrically stable medium. .lnsuchcasa.however, therequirement .o'fa high velocity of alternation of thecells must be..f.ulfille.d,.involving a high velocity. of the runnenwheelwhichin turn involveslcertain difiirelativelyllowangular velocitywhich .is only ,a

fraction of that of thearc proper. These results are tefiectedby successively opening and. closing the entrances to the quenchingeells, surrounding .the. contacts, .by. means of a,-rotating--arc :dls-

.tributing.tube or timing tubefunctioningiin the same manner, as a -sli'de valve.

The number of orifices in :the timing vtu'be differs by '-1..from :the number :of :quenching cells. ..Thus, if; arcertain' cell a.-is.coneni:or,i.in :other words, -,,one.::ori'fice..:of zthevtiming avtubeiis saligne'd 12 Claims. (Cl..-20.0--148 $2 withan orifice of a cooling celLthenin aplace :an'gula-rly remote by 180 'the inverse .situation will arise, namely a :pantition of the timing tube :will :block the entrance to another cell orifice. By :su'itably :selecting the width of the-orifices :and :of the partitions, both in the timing tube aandgin the cells, .theeffect may be achievedthat only one celltis open While :several f adjacent cells 'arezpartly closed and :the remaining cells totally closed, so that the g s will escape merely atone =side,-lthe are being thusdriven into that opening Where there .is l a top :speed namely 1 into ,the fully open :cell. :As the timing =tube continues to re- :tate, the succeeding inletprifices of the cooling cells :are :successively fully opened. Due the -diiference-jof '--1 between-the numbers-of orifices :the itiming 'tube and in the quenching cells, thezdirectioniof progressof =fu1l Opening ofsuc- :cessive quenching :cell orifices is opposite to the direction (of rotation of the timingtube. .E'urv.thermore, the speed of opening of successive uenching cell :orifices "is such .that the orifices throughout an angle of are successively 'opened -duringrotationof the-timing tube through an {angle asubtending an arc vequal in length to half the sum of the "widths ,of one orifice ,and ione partition. Therefore, the arc travels .around the: circumference of the timing tube at av speed which is a highmultiple of that of the tubemo- :tion. Thespeed of-thearc on the circumference .of the .tubelis proportional .t0 the linear speed of a non-rotatable mobile contact and to .the pitch of a thread interconnecting the contact and .the tube. .A further angular displacementby the average width of a celland partitionbrings about the :initial state, .the .arc ,thus penetrating .all ,cells ,throughout .,the circumference. It will be apparent that during asrnall ,.angular displacement of the tube the .arc travels completely aroundthe circumference of the timing tube.

iObviously, the general arrangement may be chosen in such manner Without in any way dew parting fromthe "scope of the present invention that the timing 'tube-remains-stationary while the cellsare-rotated. It='isalso possibleif desired, to arrange said orifices on :the circumference at tlifierent levels varying their size 'or width in ssuch manner as to increase -t-he disintegrating effect and-thereby: the coolingefiect 'uponitheare.

JI'he 'object of :the present invention is :il'lus- -ttrated merely byrwayxof;example-in the accompanying drawing showing one constructionalqem- :bodiment :of :myxnew quenching arrangement of iem diment 'lnby mo :means. exhaustive rat the possibilities of carrying into efiect the basic idea of my invention.

In the drawing:

Fig. l is a longitudinal sectional view through a circuit breaker embodying my invention,

Fig. 2 is a somewhat diagrammatic transverse sectional view, substantially on the line :Lz:cz of Fig. 1, illustrating the orifices and their interrelation, and

Fig. 3 is a transverse sectional view on the line J23$3 Of Fig. 1.

Referring to Fig. 1 the illustrated embodiment of the invention circuit breaker includes a carrier or mounting plate I for stationary contacts 2 engageable by a non-rotatable longitudinally movable contact 3. Such carrier I is mounted within an outer casing 16. Surrounding and concentric with the movable contact 3 is a control or timing tube 4 serving at the same time for admission to the interior of the circuit breaker casing. Said tube 4 is guided at its upper end by said carrier l and at its lower end rests firmly in a bearing I! carried by the stationary support 9 mounted in the outer casing [5. Thus said tube 4 is secured against any other than a turning movement. The movable contact 3 is provided with a thread 5 having a large pitch and engaging a thread on the inner side of tube 4 or of the support I! connected therewith so that any sliding movement of contact 3 effects rotation of tube 4. Blast air is introduced into tube 4 through orifices 6 provided atthe circumference thereof. The partitions between said orifices 6 are arranged to reduce air losses to a minimum. The top part of the tube 4 is provided throughout its circumference with slots 1 against which the quenching cells 18 are arranged as referred to above and or shown in Fig. 2. These quenching cells I8 are surrounded by fins 8 which are made either of metal or of insulating material. The hot gases, if required may pass through additional metallic cooling fins l9 before leaving the casing 18 as indicated by the arrow in Fig. 1. In the support 9 carrying the bearing ll of tube 4 stationary electrical contacts I!) engage the longitudinally displaceable contact 3 to provide for current flow between the electric terminals II and I2 when

contacts

2 and 3 are engaged. Longitudinal movement of contact 3 is efiected through an electrically insulated lever [3, but it will be understood that contact 3 may be operated by air pressure, or other means, in a known manner.

' The main cooling air enters through an inlet pipe l4 into an inner casing l5 within the outer casing IS. A timing tube of the same design and with the same arrangement of cells may, however, be used also in oil circuit breakers. In the case of gas-generating circuit breakers where no blast air is introduced since the arc itself generates gases from the surrounding medium, it is preferable to reduce as far as possible the gap between the movable contact 3 and the timing tube 4 wherein the gases are generated, thus insuring a maximum gas generation.

In the circuit breaker described above the arc while being broken is brought into cells with a fresh ionized medium. Thus its voltage always rises rapidly after its entrance into the cell. While the arc burns inside the cell its voltage drops as the medium is being ionized.

The alternation of the medium as described before manifests itself in the course of the-arc voltage curve which regularly rises and falls in dependence on the turning movement of the control tube.

The alternating increase and decrease of the electric strength of the insulating medium and consequently of the voltage of the electric arc efiects oscillations of the electric circuit into which the arc is switched through the influence of the capacity and self-induction included therein. Such oscillations occur also in any switch during breaking. In the circuit breaker according to my invention this effect is increased and the frequency of the oscillations may be controlled by changing the rate of rotation of the control or timing tube. A further increase of the oscillations of the electric circuit may be achieved by connecting a capacity or self inductance in series or in parallel with the circuit breaker. Thereby both voltage and current of the arc will be favorably infiuenced and conditions will be created for extinguishing the are as a more rapid passage of the current through the zero value is attained.

While a specific embodiment of my invention has been shown and described in detail to illustrate the application of the principles thereto, it should be understood that the invention may be otherwise embodied without departing from such principles.

What I claim as my invention is:

1. In an electric circuit breaker having a fixed contact, a substantially non-rotatable movable contact cooperable with said fixed contact, and means for moving said movable contact to open and close the circuit breaker, arc quenching means comprising, in combination, a plurality of arc cooling cells arranged adjacent the junction of the contacts and having alternating arc entry orifices and cell separating partitions conjointly forming the circumference of a circle; valve means mounted for movement relative to the cell orifices and having orifice means and closing partition means successively alignable with adjacent cell orifices to open and close the same; and means operable by the movable contact to move said valve means relatively to the orifices to suecessively Open adjacent orifices and successively close the same to direct the are successively into adjacent orifices.

2. In an electric circuit breaker having a fixed contact, a substantially non-rotatable movable contact cooperable with said fixed contact, and means for movin said movable contact to open and close the circuit breaker, arc quenching means comprising, in combination, a plurality of arc cooling cells arranged adjacent the junction of the contacts and having alternating arc entry orifices and cell separating partitions conjointly forming the circumference of a circle substantially concentric with the direction of movement of the movable contact; rotatable valve means mounted for movement relative to the cell orifices and having orifice means and closing partition means successively alignable with adjacent cell orifices to open and close the same; and means operable by the movable contact to rotate said valve means relatively to the orifices to successively open adjacent orifices and successively close the same to direct the are successively into adjacent orifices.

.,.1nem ber'having circumferentially arranged ports.

5. Arc quenching means as claimed in claim 2 in which said valve means comprises a cylindrical member having uniformly spaced circumferentially arranged ports in the plane of the orifices, the number of ports differing from the number of orifices.

6. Arc quenching means as claimed in claim 2 in which said valve means comprises a cylindrical member having uniformly spaced circumferentially arranged ports in the plane of the orifices, the number of ports differing by one from the number of orifices.

'7. Arc quenching means as claimed in claim 2 in which said valve means comprises a cylindrical member having uniformly spaced circumferentially arranged ports in the plane of the orifices, the number of ports differing by one from the number of orifices, and the circumferential spacing of said ports being greater than the circumferential widths of said ports.

8. Arc quenching means as claimed in claim 2 in which said valve means comprises a cylindrical member having uniformly spaced circumferentially arranged ports in the plane of the orifices, the number of ports differing by one from the number of orifices, and the circumferential spacing of said ports being greater than the circumferential widths of said ports and the circumferential widths of the orifices.

9. Arc quenching means as claimed in claim 2 in which said valve means comprises a cylindrical member having uniformly spaced circumferentially arranged ports arranged at different levels throughout the circumference of said member, the number of ports difiering by one from the number or orifices, and the circumferential spacing of said ports being greater than the circumferential widths of said ports and the circumferential widths of the orifices.

10. Are quenching means as claimed in claim 2 in which said valve means comprises a cylindrical member having circumferentially arranged ports; and including a high pitch threaded engagement between the movable contact and said member to effect rotation of said member upon longitudinal motion of the movable contact.

11. Are quenching means as claimed in claim 2 in which said valve means comprises a cylindrical member having circumferentially arranged ports; and including means for admitting air to the interior of said member.

12. Arc quenching means as claimed in claim 2 in which said valve means comprises a cylindrical member having circumferentially arranged ports; and including a high pitch threaded engagement between the movable contact and said member to effect rotation of said member upon longitudinal motion of the movable contact; and means for admitting air to the interior of said member.

FR-ANTIEK HoU'r.

No references cited.