US1942678A - Circuit interrupter - Google Patents

Description

Fig. 11 is a view, in elevation. of an insulating enlarged in Figs. 3 and 4. The insulating member 11 Patented Jan. 9, 1934 1,942,678 cmcm'r m'rnaamnn Walter M. Austin, Pittsburgh, Pa., assignor to Westinghouse Electric & Manufacturing Company, a corporation 0! Pennsylvania Application May 20, 1930. serial No. 453,921

19 Claims.

My invention relates to circuit interrupters and particularly to arc-extinguishing devices therefor.

One object of my invention is to provide a circuit interrupter with an arc-extinguishing device that shall conduct current laterally therethrough when a circuit is completed thereby.

Another object of my invention is to provide a circuit interrupter with a deionizing device that shall establish a plurality of arcs in series with the conducting members thereof when the circuit is being opened, thereby eliminating the arctransferring means heretofore employed with deionizing structures.

A further object of my invention is to provide a deionizing device for an arc with a winding that shall effect a gyrating movement to the arc and be compressed upon itself to effect a direct longitudinal path for the current therethrough to render the winding ineffective for producing a magnetic field when the circuit interrupter is in closed-circuit position.

My invention will best be understood by referring to the following specification in conjunction with the accompanying drawings, wherein:

Figure 1 is a fragmentary view, partly in section and partly in elevation, of an arc-extingishing device embodying my invention shown in open-circuit position,

Fig. 2 is a view, in front elevation, of the structure shown in Fig. 1,

Fig. 3 is an enlarged plan view of an insulating guide and spacing member shown in Fig. 1,

Fig. 4 is a sectional view of the structure illustrated in Fig. 3, taken along the line IV- -IV thereof,

Fig. 5 is a sectional view of the movable current-carrying portion shown in Fig. 6, taken along the line V-V thereof,

Fig. 6 Ba plan view of the structure shown in Fig. 5,

Fig. 7 is a plan view of a winding shown in Fig. 1,

of Fig. 7 and partly in elevation, of the winding shown in Figs. 7 and 8, having the'turns thereof expanded,

Fig. 10 is a plan view of one of the spaced conducting members employed in my invention,

guide and actuating member for the conducting plates shown in Fig. 10, and

Fig. 12 is a transverse sectional view of the insulating guide and actuating member shown in Fig. 11, taken along the line xn xn thereof.

Fig. 13 is a diagrammatic view showing the direction of current flow and the magnetic flux set up thereby.

My invention comprises, in general, a base 1 upon which an arc-establishing and deionizing device 2 is supported by bolts 3 and is connected in an electrical circuit by means of a terminal stud 4 and nuts 5. The arc-deionizing device 2 has a movable-portion 6 connected by a lead 6a to the aforesaid circuit, portion 8 being pivoted 7 on an actuating arm 'I, which is, itself, pivoted on a supporting frame 8 and actuated to closed and to open-circuit position by a toggle system 9 and an actuating mechanism (not shown).

In a patent of Joseph Slepian, No. 1,784,760,

issued December 9, 1930, and assigned to the assignee of the present invention a deionizing device is disclosed wherein an arc is established between a pair of separable contact members and transferred into a. deionizing device where it is expaths for the arcs, over which, they are moved bythe magnetomotive force produced by a plurality of windings that are in series relation to the arcs.

In practicing my invention, I eliminate the usual separable contact members and the transfer means that moves the are from the contact members into the deionizing plates, by utilizing the spaced conducting plates of the deionizing device as the main current-carrying members.

To complete a circuit with my deionizing device,

the spaced conducting plates thereof are moved into intimate contacting relation, and a helical winding, for producing a radial field, is collapsed, in order that the current through the circuit interrupter may pass longitudinally through the plates and the winding.

The arc-establishing-and-deionizing device 2 comprises a magnetic cup-shaped member 10 having retaining lugs 11 and a centrally-extending portion 12, the latter constituting a return path for the flux passing upwardly along the wall 13 of the member. Fitting within the cylin- .-drical wall 13, a cylindrical insulating guide and spacing member 14 is disposed that is shown 14' is provided with a flange that constitutes a hollow base 15 that conforms, in size and shape, to a conducting terminal member 16 over which it snugly fits and serves as an insulating cover.

The movable portion 6 of my arc-establishingand-deionizing device comprises a conducting plate 17 having four lugs 18 thereon that constitute the supporting members for the movable member 6. A magnetic member 19, of cup-shape. is supported upon, and brazed or otherwise fastened centrally to, the conducting member 17 and is of such dimensions that it may slide freely over the centrally extending portion 12 of the magnetic member 10,

A winding 21, in the form of a helix, is riveted, or otherwise secured, at one end, to the plate 17. The winding 21 is illustrated in Figs. 7, 8 and 9 as being constructed from flat strap material in order that it may be compressed until the coils are in close contact, as shown in Fig. 8. The other end of the winding 21 is riveted to an adjacent conducting plate or washer 22 of a group that substantially conforms to the inside and outside dimensions and contour of the winding 21, except that the plates or washers are provided, on their interior and exterior edges, with teeth to be hereinafter described.

A tubular insulating guide and actuating member 23 surrounds the cup-shaped member 19 and is supported by means of an insulating block 24 and a rivet 25.

Referring to Figs. 1 and 5, it will be noted that a plurality of the conducting washers 22 are disposed between the winding 21 and the contact member 16 in spaced relation to each other, which corresponds to the open-circuit position of my circuit interrupter. Each of the washers 22 is provided with interiorly-projecting lugs or teeth 26 and with exteriorly-extending lugs or teeth 27. Th number and position of the lugs vary on each of the washers, depending upon their relative positions in the group of washers 22.

The insulating member 14 is provided with a plurality of slots 28 disposed in uniform, or other predetermined, relation, in the periphery of the inner surface of the member. The slots 28, so vary in length, that the bottoms thereof are in uniform, staggered relation to each other along the surface of the member 14. The diametrically oppositely disposed slots 28 are of the same length, in order to support its respective washers 22 resting on the bottom of the slots at two diametrically opposite points and thereby prevent the washers from becoming tilted. The outwardly extending lugs 27 engage certain of the slots 28, and it will be seen that, as the washers 22 are moved within the insulating member 14, the lugs 2'7 thereof will come into engagement with the bottoms of their associated slots 28, and the washers 22 will be supported in spaced relation to each other when the tubular actuating member 23 is in its outward open position.

A plurality of slots or grooves 31 and 32, of various lengths, are disposed on the outer surface of the insulating guide and actuating member 23. The lengths of the slots or grooves 31 and '32 are such that the-oppositely disposed slots are equal in length and the bottoms of each pair are in staggered relation to those of the other pair, as indicated in Fig. 12. The inwardly projecting lugs 26 of the washers 22 are disposed in the slots or grooves 31 and 32, and the number and positioning of the lugs 26 is such that, as the member 23 is moved outwardly, the outermost plate will be moved first, followed by a second,

a third, etc. in progressive order. The plates will thus be equally spaced by the slots or grooves 31 and 32 because of the uniformly increased lengths of successive slots. Afterthe member 23 has moved to its outermost position, the conducting washers 22 will be retained against downward movement by the engagement of the lugs 26 with the bottoms of'the slots 31 and 32 and will be prevented from moving upwardly by engagement of the lugs 27 with the bottoms of the slots 28. In such an arrangement, the conducting washers 22 are spacedapart a predetermined distance and are held in fixed positions with relation to each other and with relation to the supporting structure.

The winding 21 is made of hard-drawn copper or from an alloy of copper, the properties of which are such that the winding is resilient. That is to say, the winding 21 will function as a spring and may be completely compressed to have the turns thereof abut solidly against each other and, after the release of the force producing the compression, to have the turns return to their normal positions. The resilience of the material, taken in conjunction with the cross section thereof, should be such that an application of pressure to the winding 21 should first cause the conducting washers 22 to be moved into contact engagement with each other before the winding begins to collapse, and, during the opening movement of the switch structure, the winding should first expand before the plates begin to separate. The reason for this relation between the compression of the windings and the movement of the plates will be explained hereinafter.

It is well known in the art that copper, which is the accepted commercial material for conducting currents produces an oxide which is a very poor conductor. It is apparent that such oxides on the surface of the winding 21 and the washers 22 would defeat the purpose of the present invention by resisting the flow of current longitudinally through the abutting surfaces of the members. The surfaces of the winding 21 and the conducting washers 22 are, therefore, coated with silver or a similar material, the oxide of which is conducting and affords, at all times, a good conductive contact between adjacent contacting surfaces of the washers 22 and the winding 21.

The conducting washers 22 and the movable terminal member 17 are provided with radial slots 29 that interrupt the continuous currentconducting path in which current would be induced by the magnetic flux should uninterrupted washers be employed.

When my circuit interrupter is employed in an alternating-current circuit, it is apparent that the return path 12 for the flux provided by the winding 21, will pass through the center of the washers 22. If the washers were continuous, they would function as short-circuiting secondaries and would reduce the effective flux produced by the winding 21 which would thereby reduce the radial magnetomotive force that moves the arcs over the surfaces of the plates. are provided in the members 1'7, 19 and 22, only a few turns in the winding 21 are required to produce a suflicient magnetomotive force for moving the arcs.

In assembling my self contained arc-establishing-and-deionizing device, the contact member 16 is first mounted on the base 1 by means of the bolts 3 and the nuts 5. The movable unit 6 is then assembled, as shown in Fig. 5, and

the insulating member 14 is then placed over the When slots 29 member 6, the slots 28 thereof engaging the extensions 27 of the conducting members 22. The

' magnetic cup-shaped member is then placed over the member 14, the lugs 18 extending through apertures 32 provided in the bottom of the member 10. The unit thus assembled is mounted on the contact member 16 by means of the bolts 33 that extend through the flanges 11 of the magnetic member 10 and through the insulating member 14, thereby effecting a solid pressure-resisting structure. The actuating arm 7 is then attached to the lugs 18 of the movable member 'G'by bolts 34 The operation of my extinguishing device w now be described. Assuming the circuit interrupter to be in the open-circuit position shown in Fig. 1, upon the actuation of the toggle system 9, the actuating arm 7 is moved toward the base i, carrying the plate 17, the winding 21 and the conducting washers 22 along therewith. The winding 21 is of such resiliency, as pointed out above,'.thatq the conducting plates 22 will be moved into intimate engagement with each'other and with the contact member 16 in order to complete a current path therethrough and through the winding 21 before the winding is compressed.

The object of this construction is to retain the winding 21 in energizable position when current begins to flow therethrough and through the several conducting members, in order that, in the presence of a short-circuit condition that would cause the immediate, separation of the conducting members, the radial magnetic field will be effective to immediately move the arcs as they are drawn. The same result will also be effected when the circuit interrupter is actuated to open position in the presence of normal current fiowing therethrough. That is to say, the winding will be first opened to create a magnetic field before the arcs are drawn.

When the circuit interrupter is closed, the breaking of the toggle system 9 by a tripping mechanism (not shown), will cause the circuit interrupter to move to open-circuit position. The actuating arm '7 is moved by means of the springs 30, and, for the reasons referred to above, the winding 21 first extends to permit current to flow along the helical path thereof in order to build up a radial magnetic field. Thereafter, the internally projecting lugs 26 are engaged by the bottoms of the slots 31, in sequence, and moved until the outwardly extending lugs 27 engage the bottoms of the slots 28 in the insulating member 14. In this operation, arcs will be established between the washers 22 that will be moved rapidly over the adjacent surfaces of the plates by the radial magnetic field set up by the coil 21, as illustrated diagrammatically in Fig. 13, until the arc is extinguished, when the current thereof passes through the zero point of its alternating cycle. Reinitiation of the are, thereafter, will be prevented because of the rapid deionization of the space adjacentto each of the plates, in a manner outlined in the above noted application.

It will thus be seen that I have provided a self-contained arc-establishing-and-deionizing means that eliminates the usual separable conordinarily be produced thereby during normal current flow. By employing materials that are non-oxidizing, or. which acquire a conductive oxide, I obtain a path of low resistance for the current when the members are pressed into firm engagement with each other.

While I have described the operation of my circuit interrupter when interrupting an alternating-current circuit, it is to be understoodthat it is equally effective for interrupting direct-current circuits when thevoltage to be interrupted is in a predetermined relation to the number of arcs established between the plates.

In the above-mentioned Patent 1,784,760 of Joseph Slepian, it was demonstrated that, after arc extinguishment, the rapid deionization 'of the space adjacent to one side of each plate would produce such dielectric properties in the spaces between the plates that the spaces would withstand approximately 300 R. M. S. volts. When the spaced plates are employed to interrupt a direct-current circuit, the arc will be extinguished and prevented from restriking when the voltage gradient across the plate is such that the volts per space will be below approximately30 volts. Suillcient plates should be provided to maintain the voltage gradient below the above mentioned values in order to afford an ample factor-of safety and insure that the arc will not be reinitiated after extinguishment.

While I have described and illustrated a single embodiment of my invention, it is to be understood by those skilled in the art that many changes, omissions and additions and substitutions may be made therein without departing from the spirit and scope of my invention.

I claim as my invention:

1. A circuit interrupter including a plurality of relatively movable series-related conducting members, means for completing a circuit by moving said members into intimate engagement, means for separating the members, anda guide member having slots of different lengths for releasably retaining the members in separated positions.

2. Circuit-interrupting means including aplurality of disc-type conducting members, means for causing a plurality of arcs betwen said members in series relation to each other and to the members, a coil having adjacent turns movable into contacting relation for moving said arcs rapidly in the spaces between said members, and

means confining each terminal of each of said arc to an annularpath.

3. Circuit-interrupting means including a plurality of members movable into contacting relation to complete a circuit, a winding having adjacent turns movable into contacting relation in series with saidmembers, said members being movable by means of said winding.

4. Circuit-interrupting means including a plu rality of disc-type conducting members movable into superposed contacting relation with each 0th r to complete a circuit, means for separating said members to thereby draw an arc'between their superposed faces, means for producing a substantially radial magnetic field in the space between said members. and means confining both terminals of said are to move in an annular path.

5. Circuit-interrupting means including a plu rality of annular conducting members movable into superposed contacting relation with. each other to complete a circuit, means for separating said members to thereby draw an arc between their superposed faces, means for producinga substantially radial magnetic field in the space between said members, and said, plurality of conducting members providing annular paths on which both terminals or the are are movable by said magnetic field.

6. Circuit-interrupting means including a helix of conducting material, three or more disc-type conducting members movable into superposed contacting relation with each other to complete a circuit, said disc-type members being substantially normal to, and symmetrical about, the axis oi said helix, and means for separating said members to' thereby draw a plurality of arcs between their superposed laces.

7. Circuit-interrupting means including a helix of conducting material, three or more annular conducting members movable into superposed contacting relation with each other to complete a circuit, said annular members being substantially normal to, and symmetrical about, the axis of said helix. and means for separating said members to thereby draw a plurality of arcs between their superposed faces, and means confining movement of said plurality oi arcs to an annular path.

8. Circuit-interrupting means including a helix of conducting material, a plurality of disc-type conducting members movable into superposed contacting relation with each other to complete a circuit, said disc-type members being substantially normal to, and symmetrical about, the axis oi. said helix, and means for separating said members to thereby draw an are between their superposed iaces, and means for moving said helix, said movement of said helix first moving said conducting members into contact with each other and then moving its own turns into contacting relation with each other in closing said circuit interrupting means.

9. In a circuit interrupter, more than three conducting members, said conducting members having open spaces therebetween when the circuit interrupter is in open position, each of said spaces providing an annular path for share. and

. insulating means outside of said spaces between the conducting members providing a closure for each of said spaces around at least the major pa t of the periphery thereof.

10. In a circuit interrupter, more than three conducting members, said conducting members having open spaces therebetween when the circuit interrupter is in open position, each of said spaces providing an annular path for an arc, and means 01' insulating material defining the inner and outer edges of said annular paths around the major portion oi their perimeters, said means of insulating material lying entirely outside of the spaces between said conducting members.

11. In a circuit interrupter, more than three conducting members, said conducting members having open spaces therebetween when the circuit interrupter is in open position, each of said spaces providing an annular path for an are, means of insulating material defining the inner and outer edges of said annular paths around the major portion of their perimeters, said means of insulating material lying entirely outside of the spaces between said conducting members, and said means of insulating material having recesses therein engaged by said conducting members.

12. In a circuit interrupter, more than three conducting members, said conducting members having open spaces therebetween when the circuit interrupter is in open position, each of said spacesprovidinganannularpathioranarc, insulating means outside of said spaces between the conducting member's providing a-closure for eachoisaidspacesaroundatlesstthemajor part of the periphery thereof, and said conducting members being movable 'relative to said mans oiinsulatingmaterialtoeloseupthe spaces between the conducting members.

13. In a circuit interrupter, a plurality of plates or conducting material having spaces therebetween when the circuit interrupter h in open position and providing a recurrent path for the arc, aligned openings through said plates, means defining the major portion at the inner edge oi said recurrent path comprising an inner member of insulating material extending thrown said aligned openings, and means defining the major portion of the outer edge 0! said recurrent path comprising an outer member of insulating material surrounding the outer edges of said plates.

14. In a circuit interrupter, a plurality of plates or conducting material having spaces therebetween when the circuit interrupter is in Open position and providing a recurrent path for the are, aligned openings through said plates, means defining the major portion 01 the inner edge or said recurrent path comprising an inner member oi insulating material extending through, said aligned openings, means defining the major portion of the outer edge 0! said recurrent path comprising an outer member of insulating material surrounding the outer edges of said plates, and said plates of conducting material being movablebetween said inner and outer members of insulating material into contacting relation.

15. In a circuit interrupter, a plurality 01' plates of conducting material having spaces therebetween when the circuit interrupter is in open position and providing a recurrent path for the arc, aligned openings through said plates, means defining the major portion of the inner edge of said recurrent path comprising an inner member of insulating material extending through said 190 aligned openings, means defining the major portion of the outer edge of said recurrent path comprising an outer member of insulating material surrounding the outer edges of said plates, and a coil wound between said inner and outer members oi insulating material tor causing a substantially radial magnetic field in the spaces between said plates.

16. In a circuit interrupter, a plurality of plates of conducting material having spaces therebetween when the circuit interrupter is in open position and providing a recurrent path for the are, aligned openings through said plates, means defining the major portion of the inner edge of said recurrent path comprising an inner member of insulating material extending through said aligned openings, means defining the major portion of the outer edge oi said recurrent path comprising an outer member oi insulating material surrounding the outer edges of said 40. plates, and a coil wound between said inner and outer members of insulating material for causing a substantially radial magnetic field in the spaces between said plates.

17. In a circuit interrupter, a plurality of plates oi conducting material for causing a plurality of short arcs therebetween, a pair of members of insulating material engaging said plates, said members of insulating material being movable relative to each other, said movement causing said coil being collapsible upon the movement of said pair of members of insulating material.

19. In a circuit interrupter, a plurality of plates of conducting material for causing a plurality of short arcs therebetween, a pair of members of insulating material engaging said plates, said members of insulating material being movable relative to each other, and one of said insulating members having means for successively engaging said plates and moving them to open and close spaces therebetween.

WALTER M. AUSTIN.

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