US1894339A - Electric switch - Google Patents

Description

Jan. 17, 1933. ug- 1N 1,894,339

ELECTRIC SWITCH Original Filed June 1, 1928 Fig.4

OOOOOOOOO OOOOOOO y INVENIOR Arfhur 0 Ava/m TTORNEY ARTHUR 0. AUSTIN, F NEAR BARBERTON, OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS,

Patented Jan. 17, 1933 UNITED STATES PATENT OFFIC TO THE OHIO BRASS COMPANY, OF MANSFIELD, OHIO, A CORPORATION OF NEW JERSEY ELECTRIC SWITCH Application filed June 1, 1928, Serial No. 282,215. Renewed February 10, 1931.

This invention relates to high potential oil break switches and has for one of its objects the provision of an oil break switch which shall be simple and economical to manufacture and which shall be efficient in operation. A further object is to provide an oil break switch in which the insulator bushings for the conductor leads will also serve as insulation for the switch operating members. Other objects and advantages will appear from the following description.

The invention is exemplified in the combination and arrangement of parts shown in the accompanying drawing and described in the following specification, and it is more particularly pointed out in the appended claims.

In the drawing:

Fig. 1 is an elevation with parts in section showing one embodiment of the present invention.

Fig. 2 is a fragmentary bottom plan view of a part of the switch operating mechanism.

Fig. 3 is a fragmentary elevation of the connection between the conductor terminal and the switch operating mechanism.

Fig. 4 is a fragmentary top plan view substantially on line 4- -4 of Fig. 1.

Fig. is a horizontal section on line 5-5 of Fi .1.

igh voltage circuit breakers are a source of considerable expense and trouble on large high voltage systems. In order to lower the cost of manufacture and to obtain improved operation of circuit breakers, I have devised a new type of circuit breaker which has advantages over the ordinary types for many cases.

In the form of the invention shown in the drawing, the high voltage leads 10 and 11 enter through bushings 12 and 13. The contactarms 14 and 15 are attached to the lower end of the rods 16 and 17 respectively running through the bushings. The conductor rods 16 and 17 are free to rotate in the bushings as they simply pass through the tubu-' lar openings formed by the metal tubes 18 in the bushing which is common construction in many types.

The rotating conductors 16 and 17 are provided with weather caps 19 so that water will be prevented entering the bushings. The rotating members 16 and 17 are provided with arms 20 which are connected by links 21 to an arm 22 mounted on the top of rotating insulator stacks 23 and 24. The link mechanism connecting the rotating rods 16 and 17 is such that the rotation of the insulator stacks 23 and 24 will cause the rods to rotate.

The insulator stacks are provided with shafts 25 and 26 which, in turn, have shives 27 and 28 connected by cables or chains 29 and 30 to a drive pulley 31. The operation of the drive pulley rotates the insulator stacks which, in turn, rotate the operating rods 16 and 17 so that the arms 14 and 15 may be made to advance or recede with respect to each other.

The insulator stacks are comparatively inexpensive and easily installed compared to the usual operating rods placed beneath the oil. Since the operating mechanism is entirely outside of the oil circuit breaker case, the deterioration of the oil does not affect the insulation or performance of these members. By using bushings which have internal screens or internal current transformers 32, it is possible to provide very efficient insulation for all conditions.

If the oil level allows an insulating zone between the surface of the oil and the switch cover, it is possible to prevent any direct leakage at normal frequency over the surface of the bushing, even though the oil may have a very low resistance. This insulating zone being screened internally by the current transformer 32 which acts as a flux control, as explained in my prior Patent 1,699,342 will not have a static discharge over the surface and may be used effectively to prevent a coating or carbonized path over the surface of the bushing due to the flow of current through oil or deposit on the bushing. With this arrangement, much of the conducting material in the oil will settle to the bottom of the tank, permitting an improvement in the insulating value of the oil.

In the ordinary construction, where a meta1 sleeve projects down below the surface of the oil and materially reduces the path, conducting material in the oil tends to build up and bridge the insulating surface.

The present type of construction also lends itself to installations where it is desired to eliminate an air space at the top above the surface of the oil so as to prevent explosions. Where the entire case is filled with oil, an expansion of the oil due to a rise in temperature or due to an opening of a heavy arc might set up a pressure which would rupture the tank or container. This difficulty has been provided for in my previous application Number 7 22,204 filed June 25, 1924, in which an expansion chamber 40 is provided with an opening below the surface of the oil. This expansion chamber may run entirely around the case or be of any suitable form such that the flow of the oil due to the compression of the air or glands 41 in the expansion chamber, will not be affected by the inertia of the oil. 7

, With this class of construction the length of the bushings may be greatly reduced. This permits of a smaller tank, all of which tends to reduce the cost of the circuit breaker.

It is evident that various forms of contact members may be used and absorbing baffles may be attached to the bushings or to the tank to break up large pockets of hot gas. The contact members may be provided with an expansion chamber as in common practice 7 in some bushings or with a multiplicity of contacts operating in multiple or in series so as to provide a long eflective resistance in the path of the are quickly and so as to break up large pockets of hot gas in order that the heat generated may be readily absorbed by the oil without danger of causing an arc to ground.

The contact arms may be attached to conducting rods which have considerable torsional resilience so that when the switch is in closed position, there will be a considerable torsional displacement in the contact members or in the springs forming the contact arms or between the contact arms and the conducting rods. When the parts are placed under stress by the closing action of the switch, a slight additional movement on the part of the operating insulator stacks or rods through the bushings will permit of one contact member sliding past the other and a ql ick opening of the switch resulting from the stored energy in the conductor rods due to their torsional displacement. It is evident that this release may be afiected magnetically either by the current flowing through the bushing or at any point in the conducting mechanism, or by an external circuit operating through a current transformer incorporated in the bushing or in the circuit outside of the bushing.

I claim:

1. The combination with a housing, of a pair of bushing insulators extendingthrough the wall of said housing, conductor rods extending through said insulators, laterally extending contact arms connected with said respective conductor rods within said housing and arranged to contact with each other to form electrical connection between said conductor rods, and means for simultaneously rotating said conductor rods to move said contact arms together from opposite directions. 7 Y

2. A high potential switch comprising a housing, a bushing insulator extending through the wall of said housing, an operating rodextending through said bushing insulator and rotatably mounted therein, a

switch contact connected with said rod'withinsaid housing, and insulated means connected' with said rod outside of said housing for rotating said rod, there being resilient yielding connection between said rotating means and said switch contact. r

3. A high potential switch comprising a housing, a bushing insulator extending through the wall of said housing, a switch contact disposed within said housing, an operating rod rotatably mounted in said bushing insulator and secured to said switch contact, an operating arm connected with said rod outside of said housing, said arm having a socket'for receiving theend of said rod provided with an imperit'orate cover for the end of said rod and having a flange over.- lapping the opening through which said rod projects from said insulator to exclude water from said insulator, and a conductor electrigally connected with the outer end of said ro 4. In a high potential switch comprising an oil containing housing, a pair of bushing insulators extending through thewall of said housing, operating rods rotatably mounted in said bushing insulators respectively, switch contacts carried by said operating rod and movable into and out of contact with each other when said rods ar rotated, and insulated operating means for rotating said rods disposed outside of said housing.

5. A high potential switch comprising an oil containing housing, a pair of bushing insulators extending through'the wall of said housing and fixed thereto, combined operating rods and conductor leads extending through said bushingiinsulators and rotatably mounted therein, contact arms secured to the inner ends of. said combined rods and leads and arranged to engage each other, and operating means for rotating said rods to bring said contact arms into engagement when moved together from opposite directions, the connection between said contact arms and operating mechanism having sufficient resiliency to permit said connection to be placed under resilient stress and to permit said contact arms to pass each other when the connection is so stressed to effect quick disconnection of said arms.

6. A high potential switch comprising an oil containing housing, a pair of bushing insulators extending through the top of said housing and fixed thereto, operating rods extending through said bushing insulators and rotatable therein, contact arms secured to said rods within said housing and arranged to engage each other at a point below the surface level of the oil within said housing, insulated means outside of said housing for rotating said rods to effect contact of said arms, the connection between said arms and operating means having suflicient resiliency to permit said arms to pass when placed under stress by said rotating means and thus to effect quick separation of said arms.

7. A high potential switch comprising an oil containing housing, a pair of bushings extending through the top of said housing and fixed thereto, a rod extending through said bushings and rotatable therein, said contacts secured to the inner ends of said rods respectively, operating arms secured to the outer ends of said rods respectively, rotatable shafts having insulating sections connected with said operating arms, and means for rotating said shafts to move said arms and 0p erate said switch contacts through the rotation of said rods.

8. An electric switch comprising a housing, a bushing insulator extending through the wall of said housing and having its longitudinal axis in fixed position relative to said housing, a contact member supported by said bushing insulator, operating means for said contact member arranged to rotate said contact member about the axis of said insulator, and a yielding connection between said operating means and contact member arranged to be placed under stress by said operating means to effect quick movement of said contact member by the energy stored in said connection when under stress.

9. A switch comprising a pair of contact members, means for moving one of said contact members into contact with the other to close said switch, yielding means for exerting further force on said contact in the direction of its closing movement, said yielding means being placed under stress by said force, one of said contacts being arranged to yield to the other to permit said contacts to pass and open said switch by relative movement in the same direction as the closing movement and by quick action under the stress in said yielding means.

10. In an electric switch, a rotatable operating member, a switch blade extending laterally from the axis of said member and having a contact portion spaced from the axis of said member, resilient connection between said contact portion and operating member, a cooperating contact, means for holding said operating member in a position to place said resilient connection under stress when said contact portion and cooperating contact are in engagement and when said switch is closed, said yielding connection being arranged to permit said contact portion to pass said cooperating contact when additional stress is placed upon said resilient connection by said operating member.

11. In a quick acting electric switch, a pair of rotatable operating members, switch blades extending laterally from the axes of said operating members respectively and having contact portions arranged to engage each other at a point between the axes of rotation of said operating members, there being yielding connection between said operating members and the respective contact portions of said blades, said yielding connections being placed under stress when said switch is closed and said blades are in operating engagement, said yielding connections being arranged to permit said blades to pass each other when additional stress is placed upon said yielding connections by said operating members.

12. In an electric switch, a rotatable operating rod, a bushing through which said rod extends, an operating arm secured to the end of said rod above said bushing, said operating arm having an imperforate weather shed covering the upper end of said bushing.

In testimony whereof I have signed my name to this specification this 26th day of May A. D. 1928.

ARTHUR O. AUSTIN.

Images