US2816197A - Switch - Google Patents

Description

Dec. 10, 1957 R. H. SAVAGE 2,816,197

SWITCH Filed Dec. 12. 1955 in V2 7') to: Robert H Savage,

His Attorney.

ni fidstates Patent SWITCH Robert H. Savage, Scotia, N. Y., assignor to General Electric Company, a corporation of New York Application December 12, 1955, Serial No. 552,636

2 Claims. (Cl. filth-150) My invention relates to switches and more particularly to switches for circuit interruption which are immersed in a fluid.

It is desirable to provide a switch which reduces arcing and eliminates current leakage between the contacts when an electrical circuit is interrupted. Previous switches employed contact members which were submerged in oil of high dielectric strength. Such an oil did not eliminate arcing but it limited the degree to which the arcing took place. While water has excellent arc suppressing properties, the use of this fluid in a switch poses the problems of electrolysis with metallic contacts and current leakage between the contacts. The invention of the persent application provides an improved fluid type switch which employs a water medium to reduce arcing and to eliminate current leakage between contacts.

Accordingly, it is an object of my invention to provide an improved fluid type switch.

It is another object of the invention to provide an improved fluid type switch in which the switch casing is filled partailly with water.

It isanother object of the invention to provide an improvf... fluid type switch which has a carbon contact member and a non-corrosive metallic contact member.

It is a further object of the invention to provide an improved fluid type switch in which a single contact member is submerged during circuit interruption to eliminate current leakage.

-'In carrying out my invention in one form, a casing which is filled partially with Water has a contact member below water level and a second contact member adapted to be inserted into and withdrawn from the water to make and break contact with the first member to provide a fluid type switch.

These and various other objects, features and advantages of the invention will be better understood from the following description taken in connection with the accompanying drawing in which the single figure of the drawing is a partial sectional view of a fluid type switch which embodies my invention.

In the single figure of the drawing, a switch is shown which comprises a generally cylindrical casing 11 of electrically insulating material with a bottom plate 12 and a removable cover 13. A stationary contact element 14 is mounted preferably within switch 10 by means of an angle contact support 15 which extends through casing 11 and is adapted to be connected in an electric circuit. An insulator 16 on the exterior surface of casing 11 extends through this casing to insulate element 14 therefrom. A contact member 17 of a conductive, non- 2,816,197 Patented Dec. 10, 1957 corrosive metal, such as-silver, is positioned oncontact support 14. Casing 11 is filled partially with water to a level 18 to submerge completely contact element 14 within the fluid. Above water level 18, an air space 19 extends to removable cover 13 of casing 11. Cover 13, which fits tightly over the edges of casing 11, has a central aperture 20 therein to provide an opening for a second movable contact element 21 with a contact support 22 and a carbon contact member 23. If it is desired, an insulator (not shown) for support 22 can be provided on the exterior surface of cover 13 to eliminate the electrically insulating material of casing 11. Contact element 21 is positioned normally above water level 18 during circuit interruption and is adapted to move within casing 11 to make and break contact with contact element 14. Support 22, which can be connected in an electric circuit, is actuated by any suitable mechanism (not shown) to move contact element 21. While one contact element is shown to be stationary, both elements can be movable within the casing. I have found that either the metallic or the carbon contact member can be submerged in the liquid. However, when a unidirectional current is employed, the carbon member should be the anode.

In the operation of switch 10, contact members 17 and 23 engage each other below water level within casing 11 during current flow through the electric circuit. When it is desired to interrupt this circuit, an actuating mechanism (not shown) withdraws contact element 21 from the water to a position above water level. The are which forms during separation of members 17 and 23 is quenched by the water while removal of member 23 from the water eliminates leakage currents between the contacts. I have also discovered that the use of a carbon contact member and a noncorrosive metallic contact member eliminates electrolysis which would occur if a pair of metallic contacts were employed in a fluid, such as water.

As will be apparent to those skilled in the art, the objects of my invention are attained by providing a carbon contact member and a non-corrosive, metallic contact member within a casing which is filled partially with water to produce a novel fluid type switch.

While other modifications of this invention and variations of apparatus which may be employed within the scope of the invention have not been described, the invention is intended to include all such as may be embraced within the following claims.

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

1. An electrical switch comprising in combination, a hollow casing, a stationary silver contact element mounted within said casing and adapted to be connected in an electric circuit, said silver element insulated from said casing, water filling partially said casing to cover said silver contact element, a second carbon contact element positioned normally above water level within said casing during circuit interruption and adapted to move within said casing to make and break contact with said first contact element, said second carbon contact element insulated from said casing and adapted to be connected in an electrical circuit.

2. A unidirectional current switch comprising a hollow casing of electrically insulating material, a stationary contact element mounted within the casing, said element comprising a contact support adapted to be connected inan electric circuit, a silver contact member on said support as a cathode in said electrical circuit, water filling partially said casing to cover said silver contact element, and a second contact element positioned normally above Water level Within said casing during circuit interruption and adapted to move within said casing to make and break contact with said first contact element, said second contact element comprising a contact support adapted to be connected in an electrical circuit, and a carbon contact member on said contact support as the anode in said electrical circuit.

References Cited in the file of this patent UNITED STATES PATENTS Bacon Mar. 15, Kelman Mar. 3, Taylor July 10, Bennett et al. Oct. 21, Rankin Mar. 31, Hilliard May 5, Mahoney Dec. 22, Hilliard Dec. 4, Day Dec. 16, lanes et a1 Oct. 7,

Images