US2030449A - Mercury switch - Google Patents

Description

Feb. 1 1936. c. HATAY 2,030,449

MERCURY SWITCH Filed April 26, 1952 INVENTOgf BY ATTORNEY Patented Feb. 11, 1936 PATENT OFFICE MERCURY SWITCH Charles Hatay, Berlin-Charlottenburg, Germany,

assignor to General Electric Company, a corporation of New York Application April 26, 1932, Serial No. 607,647 In Germany May 5, 1931 2 Claims. (Cl. 200-152) The present invention relates to mercury switches generally and more particularly the invention relates to such devices in which the make and break of the electrical contact is controlled by a member movable with respect to the other members of the device.

In devices of this type now known in the art the make and break of the electrical contact in the device is controlled by a member adapted for rotational movement. which is immersed in and raises the level of the mercury in the envelope when revolved and which is actuated by means external to the envelope of the device. Difliculty has been experienced in making the container of such devices gas tight at that part where the revolving member enters the container. This tightness, however, is essential to the successful operation of the device due to the rapid oxidation of the body of mercury which occurs when the charge of inert gas such as hydrogen, or nitrogen escapes and air takes its place.

The object of the present invention is to provide a gas tight mercury switch in which elec-' trical contact between a solid metal electrode and a mercury electrode is made and broken quickly and positively by means of a member movable with respect to the other members of said switch. Another object of the invention is to control the movements of said movable member by means external to said envelope and acting on the part of said member external to the container of the device. Further objects and advantages attaching to the device and to its use and operation will be apparent to those skilled in the art from the following particular description and from the appended claims.

In accordance with this object the invention comprises a lever extending from the interior of said switch to the exterior thereof fused through a flexible part of the wall of the container.- This flexible part of the container is an accordion like, corrugated, part commonly known in the art as a sylphon bellows and extends into the interior of the envelope of the device.

In the drawing accompanying and forming part of this specification two embodiments of my invention are shown in which Fig. i is a side elevational view of one embodiment of my invention and Fig. 2 is a similar view of another embodiment of my invention.

Like numbers denote like parts in both the figures.

Referring to Fig. l of the drawing the new and novel switch comprises a container I having a of lever 4 remains the same as in Fig. 1.

lever 4 which is fused at 3 to part 2 extends from 5 the exterior of said container I to the interior thereof and to a point above said mercury pool 6 as shown. Said lever 4 has a solid metal electrode 5, such as, an iron, copper, nickel, tungsten, or chrome iron electrode, for example, attached 10 thereto at the end thereof. Leads and 8 arefused into said container I and extend into the interior thereof. Said lead 8 is in contact with said mercury pool 6 and said lead 1 is in contact with said electrode 5. 15

A suflicient force exerted on lever 4 in the direction of the arrow brings electrode 5 into contact with mercury electrode 6, point '3 acting as the fulcrum for lever 4, and current flows through the switch. The flexibility of part 2 permits the 20 movement of lever 4 in this manner. The contact between electrode 5 and mercury electrode 6 is broken simply by releasing lever 4 which is brought back to its original position by resilient part 2. 25

The embodiment shown in Fig. 2 is in all respects similar to that shown in Fig. 1 except that the magnitude of the movement of contact 5 is increased though the magnitude of the movement of lever 4 remains the same as in the embodiment 30 discussed above. The cup I I containing the mercury electrode 6 is located near the center of container I as shown and electrode 5 is attached to a resilient, conducting member 9 sealed into the end of said container I opposite that end in 35 which lever 4 is sealed and said member 9' is electrically connected to said lead 1. End part III of lever"4 is adapted to press on said member 9 at a part of said member 9 near the end thereof which is sealed into said container I, which struc- 40 ture increases the magnitude of the movement of electrode 5 while the magnitude of movement When suflicient force is exerted on the external end of said lever 4 in the direction indicated by the 45 arrow, electrode 5 is brought into contact with and immersed in mercury electrode 6 and current flows through the device over leads I and 8. Releasing lever 4 allows'resilient member 9 to return to its normal position in which position 50 electrode 5 is out of contact with mercury electrode 6 which interrupts the flow of current through the device.

The device is successfully operated as a vacuum switch, or as a gas filled switch containing an I55 inert gas such as hydrogen, or nitrogen, as desired.

The make and break of electrical contact is more positive and takes place with greater speed in the case where the contact is between a solid metal electrode and a mercury electrode than where contact is between two solid metal electrodes, due to the fact that thelevel of the mercury electrode 6 rises when the solid metal electrode 5, made of nickel, for example, is immersed in the mercury electrode 6 and the surface of the mercury electrode 6 is first depressed at that part in contact with the solid metal electrode and then rises quickly to a greater height than the general, raised level thereof due to the capillary attraction between the merciu'y and the metal when the surface tension of the mercury is over come by the force exerted on said solid metal electrode 5. This gives a quick and positive make of electric contact between the mercury and the metal as a large area of the metal is quickly covered by the mercury. When the electrode 5 is withdrawn from the mercury electrode 6 the level of said pool recedes in the reverse manner to give a quick break of electrical contact between said electrodes. Faster and more positive makes and breaks of electrical contact are attainable when the diameter of electrode 5, consisting of chrome iron, or nickel, for example, closely approaches the diameter of the cup I due to the increased area of electrode covered by mercury electrode 6 in a shorter time and thus only a slight movement of lever 4 is then necessary to make and break the electrical contact between said electrode 5 and said mercury electrode 6 owing to the increased magnitude of movement of the level of the mercury electrode 6 when metal electrode 5 is immersed therein.

While I have shown and described and have pointed out in the annexed claims certain novel 0 features of the invention, it will be understood that various omissions, substitutions and changes in the forms and details of the, device illustrated and in its use and operation may be made by those skilled in the art without departing from the broad spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A switch comprising a tubular container having a cup-shaped enlargement at right angles to the longitudinal axis thereof, a solid metal electrode and a fluid electrode in said container, one end wall of said container being flexible, a lever fused into said flexible wall, a flexible resilient strip of conducting material fused into the opposite end wall of said container and extending toward said flexible wall,said lever and said strip overlapping for the greater part of their length in said container, said solid metal electrode being mounted on the end of said strip, said fluid electrode being in said cup-shaped enlargement, said lever on successive movements thereof making and breaking the electrical contact between said electrodes.

2. A switch comprising a tubular container having a cup-shaped enlargement at right angles to the longitudinal axis thereof, a solid metal electrode and a fluid electrode in said container, one end of said container being a. re-entrant tube having flexible walls, a lever fused into said flexible end, a flexible resilient strip of conducting material fused into the opposite end of said container and extending toward said flexible end, said lever and said strip overlapping for the greater part of their length in said container,

said solid metal electrode being mounted on the j CHARLES HATAY.

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