Abstract:
A self-extinguishing-type of fluid-blast circuit-interrupter is provided, of the single-break type, utilizing a plurality of pressure-generating chambers disposed in series relation, and compartmentalizing the extinguishing chambers so as to act transversely on series portions of the singly-drawn arc. 
     The two pressure-generating chambers are disposed opposite to the fluid-flow transmitting passages, so that there occurs a desirable reduction in temperature of the pressurized fluid prior to its subsequent injection into the arcing region.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     Applicant is not aware of any related patent applications pertinent to the present invention. 
     BRIEF SUMMARY OF THE INVENTION 
     According to the present invention, there is provided an arc-extinguishing unit comprising a stationary contact and a cooperable rod-shaped movable contact separable to establish an arc within a plurality of multiple, series, arcing chambers, with each arcing chamber communicating circuitously with a related pressure-generating chamber, the pressure within which being raised by a portion of the arc which is drawn. 
     The fluid-flow conditions are such as to force a transverse, or perpendicular flow of fluid against segmental portions of the established arc for rapid arc interruption. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a vertical sectional view taken through a fluid-blast circuit-interrupter embodying the principles of the present invention, the contact structure being illustrated in the closed-circuit position; and, 
     FIG. 2 is a view similar to that of FIG. 1, but showing the arcing conditions during the opening operation of the circuit-interrupter, with the direction of fluid-transmission flow therein being indicated. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings, and more particularly to FIG. 1 thereof, the reference numeral 1 generally designates a fluid-flow type of circuit-interrupter of the self-pressure-generating type, in which an arc-extinguishing grid, or unit structure 2 is supported from the lower end of an upper terminal-bushing 3, for example, and the arc-extinguishing grid structure 2 being disposed within a suitable surrounding enclosure 4, such as a tank, for example, a portion of the wall of which being designated by the reference numeral 4a. 
     FIG. 1 illustrates the device 1 in the closed-circuit position in which a rod-shaped movable contact 5 cooperates with an upper-disposed relatively stationary contact structure 6. 
     Adjacent to the relatively-stationary contact structure 6 is a laterally-disposed pressure-generating chamber 7, which communicates, by a remote, or somewhat distant passageway 8, that leads through an opening 8a to a generally-horizontally-extending first extinction flow passageway 9. 
     Disposed below the first extinction flow passageway 9 is, preferably, a second, lower-disposed, pressure-generating chamber 10, which again communicates somewhat remotely, by an intercommunicating flow passageway 11, to a second, lower-disposed, generally-horizontally-extending arc-extinguishing flow passage 12. 
     FIG. 1 illustrates the interrupting device 1 in the closed-circuit position; and FIG. 2 illustrates the same device 1 during the opening operation, in which segmental portions 13a, 13b, 13c and 13d of the arc 13 react upon the plurality of pressure-generating chambers 7, 10 to produce the desired fluid flow. The fluid 14 is, preferably, a suitable arc-extinguishing gas, such as sulfur-hexafluoride (SF 6 ) gas, for example. The remarkable arc-extinguishing characteristics of this gas are set forth in U.S. Pat. No. 2,757,261, issued July 31, 1956 to Harry J. Lingal et al. 
     It is desirable to have the entering extinguishing fluid flow within the horizontal passageway 9 be of a relatively-cool temperature, so as to be highly effective in causing diffusion and extinction of the established arc 13 as it approaches its cyclical zero value. As is well known, in an alternating-current circuit, the alternating-current arc diameter 13 fluctuates in accordance with its instantaneous current value; and, appropriately, as the arcing current 13 approaches its zero value, propitious conditions then occur at this time for a proper arc-extinguishing action to occur. It is then at this time that the transversely-flowing fluid 14 under pressure within the passageway 9, caused by the pressure generation within the pressure-generating chamber 7, causes a highly-effective transverse extinguishing fluid-flow action to occur through the arc portion 13b and out of the vent opening 15 to the surrounding ambient 16 externally of the arc-extinguishing grid structure 2. 
     During the existence of severe alternating-current circuit conditions, that is, for example, during high-amperage currents, the utilization of a second, lower-disposed, additional arc-extinguishing flow passageway 12, together with its concomitant pressure-generating chamber 10, causes an additional, second, desirable highly-effective fluid-flow action to take place to thereby assist and to augment the upper-disposed transversely-extending fluid-flow 9. 
     Thus, the instant invention contemplates, preferably, the use of two generally-horizontally-extending, transversely-directed fluid-flow passageways 9 and 12 to collectively act together upon different series portions 13b and 13d of the drawn arc 13. 
     In more detail, it will be observed, with reference to FIG. 1, that there are provided a plurality of vertically-spaced, horizontally-extending, insulating plate members 23-26 having apertures provided therein 18-21 to accommodate the vertical opening and closing movements of the movable rod-shaped contact 5. As shown more clearly in FIG. 2 of the drawings, the establishment of arcing 13 results in a plurality of series arc portions 13a, 13b, 13c and 13d, which are subjected to transverse, zig-zag flows of arc-extinguishing fluid in the manner indicated by the arrows 27-30. 
     Also, it will be noted that, as previously mentioned, the two pressure-generating chambers 7, 10 are so arranged and isolated, in a compartmentalized fashion, from the adjacent transverse flow passageways 9, 12 as to force the two flows 28, 30 in a circuitous fashion prior to the subsequent injection of the thus-cooled fluid 14 into the arc portions 13b, 13d. 
     A distinct effort is made in the instant disclosed construction to isolate the pressure-generating chambers 7, 10 from the remote point of fluid-ejection 9, 12. This is more clearly illustrated in FIG. 2, with particular reference being directed to the fluid-flow direction-arrows 27-30. 
     As shown in FIG. 2, a vertically extending plate-portion 33 constituting a partition means 34 is disposed laterally of the relatively stationary contact structure 6 and ensures that the gas blast flowing from the first pressure-generating chamber 7 traverses a circuitous path. 
     In addition, fluid flow 17, emanating from the second pressure-generating chamber 10, acts transversely upon a portion 13d of the arc column 13 to thereby assist in the overall arc-extinguishing action. 
     Upon arc interruption, the movable contact rod 5 moves downwardly to its fully-open-circuit position, externally of the arcing grid structure 2, and the surrounding ambient fluid 14 may then recirculate back into the interior of the arc-extinguishing grid structure 2 for the next interrupting operation of the circuit-breaker 1. 
     During the closing operation, the movable contact rod 5 moves upwardly through the second and first transversely-extending arcing passageways 12 and 9, and ultimately makes closed, contacting engagement with the upper-disposed, relatively-stationary contact fingers 6a of the stationary contact structure 6. 
     Although there has been illustrated and described a specific structure, it is to be clearly understood that the same was merely for the purpose of illustration, and that changes and modifications may readily be made therein by those skilled in the art, without departing from the spirit and scope of the invention.