US2153402A - Electric switch - Google Patents

Description

April 4, 1939. .1. F. TRITLE 2,153,402

ELECTRIC SWITCH Original Filed Sept. 29, 1937 ifgl.

31 E'lliillllllunnmmmz 1W top 3;: a John Trible,

b m y Hi Abborney.

Patented Apr. 4, lh h IEILEGTEIIG SWfiliilliil John L il ritle, Erie, Pa, assignor to General Electric @ompan York a corporation at New (Original applicationSeptembc-zr 29, 1937, Serial No. 166,277. Divided and this application June til, 19%, Serial No. 2l6,79ll

7 Claims.

My invention relates to switches for controlling electric circuits and has for its object a simple and reliable arc extinguishing means for switches.

More particularly, my invention has for its object a switch provided with magnetic means for extinguishing the arc formed between the contacts of the switch.

This application is a division of my copending application, Serial No. 166,277, filed September w 29, 1937, for Electric switch.

In carrying out my invention, I provide mag netic arc extinguishing means comprising a permanent magnet in the form of a straight bar which is mounted adjacent the fixed contact in 15 position to effectivelyextinguish an arc formed between the contacts. of a material having a high coercive force. It operates to extinguish elfectively the arc while being extremely simple and compact in construe- 2a tion.

This bar type arc-extinguishing magnet is of especial advantage where a plurality of switches are used. In accordance with my invention these switches may be mounted in side by side relation 25 with an arc-extinguishing magnet consisting of a single bar extending adjacent the fixed contacts.

For a, more complete understanding of my invention reference should be had to the accomg panying drawing of which Fig. 1 is a plan view of a group of switches embodying my invention; Fig. 2 is a side view of the device shown in Fig, 1; Fig. 3 is a sectional view along the line 33 of Fig. 1, while Fig. 4 is a sectional view along the line 4-4 35 of Fig. 1, but showing the switch in the closed circuit position.

Referring to the drawing, I have shown my invention as applied to a group of manually oper-. ated switches which are identical in construc- 40 tion, four switches being shown, each being provided with an operating member l9. As shown in Fig. 3, the operating member ID is made of a suitable electrically insulating material which preferably is a molded composition. It is pro- 45 vided with a projection or handle II which may be grasped to turn it about a pivot shaft I2 on which the member is mounted.

The member I is provided with a second projectlon I3 which, as. viewed in Fig. 3, extends 50 downward from a point adjacent the pivot shaft l2. This projection l3 engages the supporting base I4 when the operating member is in the open circuit position. On its lower end, the projection I 3 is provided with a groove or recess which 55 forms a bearing for one end of the link member This bar magnet is made (Cl. Zliil llll) iii, the other end of which rests in a bearing seat ll formed for it on the end of a cantilever spring it. The other end or" the spring is secured to the base idby means or a bolt 0 Ihe link it and the projection 63 thus constitute a toggle, the 5 movable pivot point l5 between them moving from one side to the other of a line joining the center of the shaft 02 with the bearing ll so as to thereby give the member iii a snap action and hold the member ill in eitherthe open position in as shown in Fig. 3 or the closed position shown in Fig. i.

The movable contact 2b of the switch is secured to the end of an electrically conducting strip 2i having near its center a loop or recess 22 formed 35 by bending it. This loop 22 forms a bearing for a projection 23 on the operating member 6 ii. The strip 2i is secured in place by means of a pin 26 extending loosely through an aperture provided for it in the strip on the side of the loop 22 oppogs site the contact 2t, and also loosely through an aperture provided for it in the operating member MB. A head is provided on the pin, which head engages the strip 25 and furthermore forms a seat for one end of a helical spring 25, the other 25 end of which surrounds the head 2'l of the bolt l9. A flexible conductor 28 connects the strip M with a short terminal strip 29 which is clamped to the base M by the bolt l9, the lower end of the spring 26 resting on this strip 29. In addition to 30 its other functions the bolt l9, which is preferably made of a suitable electrically conducting material such as steel or copper, serves as a terminal for the switch to which an electrical connection may be made.

The stationary contact 30 of the switch is mounted on a block 3| of electrical conducting and non-magnetic material such as brass or copper in position to be engaged by the movable contact 29, this block being in turn secured to a terminal conductor or strap 32. Preferably as shown, the block 3| is formed integrally with the strap 32. The block 3| is furthermore provided with an aperture 33 for a rod or bar 34 made of a suitable magnetizable material and serving as a magnetic blow-out device for the are formed between the contacts 20 and 39.

The magnetic bar 34 is made of a material having a high coercive force preferably an alloy consisting mainly of aluminum, nickel and iron, preferably aluminum 12%, nickel 25%, the balance being mainly iron, such as described and claimed in United States Patent No. 1,947,274, issued February 13, 1934, to William E. Finder and United States Patent No. 2,027,994, issued January 14, 1936 to Tokushichi Mishina. I have found that very eflective blow-out action is obtained with a magnetized rod or bar of this material arranged as shown in the drawing near the stationary contact, but on the side of the stationary contact opposite from the movable contact, and having its axis extending at right angles to me are drawn between the contacts or as shown at right angles to the plane of movement of the movable contact.

In the assembly of a plurality of switches as disclosed, the various blocks 31 forming the supports for stationary contacts are formed integrally with the supporting strap 32 and in suitable spaced relation with each other. Barriers or are chute members 35 made of a suitable electrically insulating material, such as building lumber, are put in place between adjacent blocks and then the magnetized rod 34 is inserted in the blocks and through suitable apertures provided for it in the arc chute members 35. An additional arc chute member 36 is provided at each end of this assembly, the rod 34 being long enough to extend through these two outer memhere. A rectangular pole piece member 31 made of a suitable non-magnetizable magnetic material, such as magnet core iron, is secured against each end of the bar 34 by screws 38 which also secure the arc chute members 33. This assembly is secured to the insulating base i4 by means of bolts 39 and 40 extending through the ends of the strip 32. As shown, the base I4 is cut away to leave a rectangular opening 4i for this assembly of the contacts, arc chutes and magnetized bar. One or both of the bolts 39 and 40 may be used as a common terminal for the switch, or terminals on the members 3i may be provided.

As shown, the operating members in are mounted on a common pivot bar l2 which is secured by means of one or more brackets 42 to the base I4 in suitably spaced relation thereto.

Obviously more than four switches can be secured together in a group and I have in fact disclosed for purposes of illustration one end only of an assembly of several groups of these switches.

In the operation, of the switch it will be observed that the supporting strip 2i for the movable contact is held in place by the helical spring 28 and furthermore when the movable contact engages the stationary contact the spring 28 yields to provide for pivot movement of the strip on the projection 23 in a clockwise direction as seen in Fig. 3, the strip coming to rest against the cuter end of the member H), as shown in Fig. 4. This movement of the movable contact provides for a wiping action on the stationary contact whereby a good electrical engagement between the contacts is assured. To further provide for this wiping action the cantilever spring 13 is constructed to apply a greater force to the member ID tending to close it than the force applied in the opposite direction by the spring 26.

It will be understood that the member Ill is forcibly moved by means of the handle II in both the opening and closing directions through an angle sufllcient to bring the pivot point l5 to the other side of the toggle straightened position whereby the force exerted by the spring i8 is reversed and the opening or closing movement of the switch is completed'bythe spring i8.

The pivot movement of the strip about the projection 23 is furthermore somewhat greater than the movement of the member ID required to reverse the force supplied by the spring l8 and consequently the contacts are separated by the snap action thereafter produced by the spring i8.

While I have shown a particular embodiment of my invention, it will be understood, of course, that I'do not wish to be limited thereto since many modifications may be made, and I therefore contemplate by the appended claims to cover any such modifications as fall "within the true spirit and scope of my invention.

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

1. The combination with a switch provided with cooperating movable and stationary contacts, said movable contact being mounted for movement in a predetermined plane, of a substantially straight bar shaped permanent arc extinguishing magnet adjacent said stationary contact extending in a direction substantially at right angles to saidplane of movement, said magnet being made of a material having a high coercive force consisting mainly of aluminum, nickel, and iron.

2. The combination with a plurality of switches each provided with a stationary contact and a cooperating movable contact, of a substantially straight permanent magnet mounted adjacent said stationary contacts in position eifectively to extinguish arcs formed between said cooperating stationary and movable contacts.

3. The combination with a plurality of switches each provided with a plurality of pairs of cooperating movable and stationary contacts, said stationary contacts being arranged substantially in alignment with each other and said movable contacts being mounted for movement in substantially parallel planes, of a continuous arc extinguishing permanent magnet extending adjacent said stationary contacts in a direction substantially at right angles to said planes of movement, and a common support made of electrically conducting non-magnetic material for said stationary contact and said permanent magnet.

4. The combination with a plurality of switches each provided with cooperating movable and stationary contacts, said stationary contacts being arranged substantially in alignment with each other and said movable contacts being mounted for movement in substantially parallel planes, of a continuous bar are extinguishing permanent magnet adjacent said stationary contacts, said magnet being made of a material having a high coercive force consisting mainly of aluminum, nickel and iron and a common support made of electrically conducting non-magnetic material for said stationary contacts and said permanent magnet.

5. An electric switch comprising a plurality of stationary contacts, a support for said contacts made of electrically conducting non-magnetic material, a substantially straight permanent magnet mounted on said support, and a plurality of movable contacts cooperating with said stationary contacts and mounted for movement in planes substantially at right angles to said permanent magnet.

6. An electric switch comprising a plurality of stationary contacts, a support for said contacts made of electrically conducting material, said support being provided with an aperture, a substantially straight permanent magnet extending through said aperture, and a plurality of movable contacts cooperating with said stationary contacts and mounted for movement in planes substantially at right angles to said permanent magnet.

7. An electric switch comprising a plurality of blocks made of electrically conducting material, means securing said blocks together in spaced relation with each other, a stationary contact secured to each of said blocks, said contacts being in alignment with each other, each of said blocks being provided with an aperture closely adjacent its contact and said apertures being in alignment with each other, a plurality of arc barriers between said blocks, said arc barriers being provided with an aperture, a permanent magnet extending through the apertures in said blocks and through the apertures in said are barriers so as to holdthe arc barriers in' a predetermined relation with said blocks, and a plurality of movable contacts cooperating with said stationary contacts and mounted for movement in planes substantially perpendicular to 10

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