US 2449439 A
Description (OCR text may contain errors)
:inventor Seept. 14, 1 948. L. M. wlTTLlNGr-:R
MERCURY INTERRUPTER Filed Nov. 1, 194s Patented Sept. 14, 1948 INTERRUPTEB Leonard M. Wittlinger, Linden, Mich., acsignor to VGeneral Motors Corporation, Detroit, Mich., a corporation of Delaware Application November 1, 1946, Serial No. 707,159
1 Claim. 1
This invention relates to circuit interrupters and more particularly to mercury type interrupters which operate automatically when connected to a source of direct current power to Y make and break the circuit to provide pulsating current therein. This general type of interrupter is disclosed in United States Patent #2,107,742, issued to Samuel Ruben. In that type, one of the electrodes having an accurately deiined area and formed of certain material, as an illustration carbon was placed'in contact with a mercury pool, which was in turn connected to an electrode of opposite polarity. When these two electrodes were connected to a suitable source of direct current, the intensity of said curzoo-113) in which rapid cooling of 'the same will be obtained.
It is a still further object of my invention to provide a mercury interrupter operating at a mentwas concentrated at the surface area of the current had stopped, the mercury vapor recondensed into liquid mercury, completing a conductive circuit again, and the current immediately began to ow. This action, of. course, is repeated, and an interrupter of pulsating action resulted.
In the type of interrupter as shown by the Ruben patent, the carbon electrode is shown as the lower one, the mercury pool being supported so that the carbon electrode projects up into the same. A similar type of interrupter is shown by the Bain Patent #2,273,921, in which a smaller carbon disc is shown in the bottom of a sealed receptacle, supported in a circular ceramic disc. A conductive electrode is swedged or otherwise permanently connected to the small carbon member, and a pool of mercury is supported above the same. However, mounting the carbon disc in a confined and restricted area. has raised certain objections. In the first place, the fact that it is so closely conned prevents the carbon disc from cooling with any great degree of rapidity, and thus reduces the frequency at which the interrupter may operate. In some instances, mercury has been able to seep into pockets below the carbon electrode, causing gaseous pressures therein.
It is, therefore, an object of my invention to provide a new and novel mounting for the heating or vaporizing electrode of a mercury type interrupter.
It is a still further object of my invention to provide a mounting for the vaporizin'g electrodel high rate of frequency.
With these and other objects in view, which will become apparent as the specification proceeds, my invention will be best understood by reference to the following specification and claim, and the illustrations in the accompanying drawing, in which the drawing is a vertical sectional view through an interrupter embody ing my invention.
Referring more specicaliy thereto, there is shown an outer envelope 2 formed of glass or other suitable insulating material in one end of which there is secured an electrode 4, which projects into the interior of the envelope and carriesy at its upper extremity a conductive plate 6. An external line 8 is permanently connected to the electrode 4. A similar external line I0 is connected to an upper electrode I2, likewise permanently supported in the envelope housing, and projecting into the interior and toward the iirst electrode. On the interior surface of the envelope there is integrally secured a cylindrical sleeve I4, concentric with the electrodes, and totally enclosing the upper one. The sleeve extends down to a greater distance than the upper electrode l2, and rigidly supports at its lower end bysuitable means circular disc I6, formed of a ceramic or other insulating material. v This disc I6 hasa small central aperture I8 on its upper face, and a larger aperture 20 on its lower face, concentric with the rst aperture, and Joining the same at approximately the mid-sec tion of the thickness of the disc. Mounted within the larger lower aperture is a disc 22, which may be formed of carbon or similar material, which is maintained in that position by suitable packing or cementing means 24 around its perimeter. The interior of the receptacle is substantially lled with mercury, which is divided into two portions 26 in the outer receptacle and 28 within the cylindrical portion. the level of the mercury within the center cylinder being slightly higher than that within the outer member. The glass sleeve I4 provides insulating means between the two pools of mercury.
the disc 22 is so designed that there will be a sumclent concentration ot current at this point to heat and vaporize the mercury in contact therewith', causing the before described vaporization oi the same to interrupt the current. The lower surface of the carbon disc being so much greater in area. where it is in contact with the mercury in bath 26 does not have its temperature raised appreciably, and no interrupter action occurs on this face. As soon as the current is broken at the upper surface, the mercury vapor recondenses, and the circuit is again reformed to permit current flow.
However, by having my carbon disc suspended out in the center of the enclosure, the heat can be conducted therefrom rapidly, and I nd that my interrupter is capable of operation at a much higher frequency than those heretofore designed. In like manner, there is no opportunity for any occluded mercury vapor behind the carbon disc to interfere with proper action of the interrupter.
The fact that the lower electrode 6 has substantial area and is mounted in proximity to the lower or cooling surface of the carbon disc also assists in cooling the latter.
In a current interrupter. a casing formed of insulating material, a pair of electrodes mounted in spaced relation in said casing, baille means of nonconducting material in said casing between the electrodes dividing said interior into a pair of chambers, a conductive pool of mercury in each chamber, said baille having an aperber.
LEONARD M. WI'ITLINGER.
REFERENCES CITED The following references are of record in the le of this patent:
UNITED STATES PATENTS Name Date Brian Dec. 24, 1940 Number