US2153401A - Electric switch - Google Patents

Description

April 4, 1939- J. F. TRITLE 2,153,401

I ELECTRIC SWTCH Filed Sept. 29, 1937 za 24 4a 2a /0 Patented Apr. 4, 1939 UNITED STATES ELECTRIC SWITCH John F. Tritle, Erie, Pa., assignor to General Electric Company, a corporation of New York Application September 29, 1937, Serial No. 166,277 y 7 Claims.

open circuit positions. Snap operating means are provided by a projection on the operating memlber near its pivot with a spring member near the projection 'and a link member between thev projection and spring member whereby a snap acting toggle is formed.

Another feature of my invention is the simple and effective mounting of the movable contact on the operating member. 'I'his consists of a spring between the operating member and the support which holds the movable contact arm on the operating member, and a projection forming a pivot for the Contact arm when it engages the stationary contact.

Magnetic arc blow-out means is provided by means of a permanent magnet in the form of a straight bar which is mounted adjacent the xed contact so as to extend in a direction perpendicular to the plane of movement of the movable contact. This bar magnet is made of a material having a high coercive force and the magnet operates to effectively extinguish the arc while being extremely simple and compact.

This straight bar type ae-extinguishing magnet is of especial advantagwhere a plurality of switches are used. In accordance with my invention these switches are mounted in side by side relation with their stationary contacts in alignment and an arc-extinguishing magnet is provided consisting of a single bar extending adjacent the xed contacts.

This magnetic arc blowout means is claimed in my copending divisional application, Serial No. 216,790, filed June 30, 1938.

For a more complete understanding of my invention reference should be had to the accompanying drawing of which Fig. l is a plan View of a group of switches embodying my invention; Fig. 2 is a side view of the device shown in Fig. l; Fig. 3 is a sectional view along the line 3-3 of Fig. 1; Fig. 4 is a sectional view along the line 55 4-4 of Fig. 1, but showing the switch in the closed 3, the operating member I is made of a suitable electrically insulating material which preferably is a molded composition. It is provided 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 III is provided with a second projection I3 which, as viewed in Fig. 3, extends downward from a point adjacent the pivot shaft I2. This projection I3 engages the supporting base I4 when the operating member is in the open circuit position. On its lower end, the projection I3 is provided with a groove or recess I5 which forms la bearing for one end of the link member I6, the other end of which rests in a bearing seat I1 formed for it on the end of a cantilever spring I8. The other end of the spring is secured to the base I4 by means of a bolt I9. The link I6 and the projection I3 thus constitute a toggle, the movable pivot point Ibetween them moving from one side to the other of a line joining the center of the shaft I2 with the bearing II so as to thereby give the member I0 a snap action and hold the member I 0 in either the open position as shown in Fig. 3 or the closed position shown in Fig. 4.

The movable contact.20 of the switch is secured to the end of an electrically conducting strip 2| having near its center a loop or recess 22 formed by bending it. This loop 22 forms a bearing for a projection 23 on the operating member I 0. The strip 2I is secured in place by means of a pin 24 extending loosely through an aperture provided for it in the strip on the side of the loop 22 opposite the contact 20, and also loosely through an aperture provided for it in the operating member I0. A head 25 is provided on the pin which head engages the strip 2| and furthermore forms a seat for one end of a helical spring 26, the other end of which surrounds the head 21 of the bolt I9. A flexible conductor 28 connects the strip 2l with a short terminal strip 29 which is clamped to the base lIII by the bolt I9, the lower end of the spring 26 resting on this strip 29. In addition to its other functions the bolt I9, 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 '3U o! the switch is mounted on a block 3l of electrical conducting material such as brass or copper in position to be engaged by the movable contact 20, this block lbeing in turn secured to a terminal conductor or str-ap 32. Preferably as shown, the block 3l 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 de- 'vice lor the arc formed, between the contacts 2li and 30.

The magnetic bar 34 is made oi 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 Patent No. 1,947,274, issued February 13, 1934, to William E. Ruder and Patent No. 2,027,994, issued January 14, 1936 to Tokushichi Mishina. I have found that very effective 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 movable contact.

to the arc drawn between the contacts or as shownv at right angles to the plane of movement o1' the In the assembly of a plurality of switches asl disclosed, the various blocks 3l forming the supports for I the stationary contacts are formed integrally with and in suitable spaced relation to the supporting strap 32. Barriers or arc 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.y An additionalk arc chute member 3B is provided at each end of this assembly, the rod 34 being long enough to extend through these two outer members. A rectangular pole piecel 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 3B 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 l2. As shown, the base I4 is cut away to leave a rectangular opening 4I for this assembly of the One cured 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 bserved that the supporting strip 2| for the movable contact is held in place by the helical spring 20 and furthermore when the movable contact engages the stationary contact `the spring 26 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 outer end of the member I0, 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 I8 is constructed to apply a greater force to the member III tending to close it than the force applied in the opposite direction by the spring 2B.

It will be understood that the member I0 is forcibly moved by means of the handle Ii in both the opening and closing directions through an angle sufficient to bring the pivot point I5 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 by the spring I8.

(The pivot movement of the strip about the projection 23` is furthermore somewhat greater than the movement of the member III required to reverse the force supplied by the spring I3 and consequently the contacts are separated by the snap action thereafter produced by the spring I8.

It will be observed that a second'projection 43 is provided on the member I0 adjacent the pin 24 but on the side of the pin opposite from the projection 23. This projection provides a pivot for the strip 2| in the event that the stationary contact is provided above the movable Contact as shown in Fig. 5, whereby a wiping action is obtained.

It will be understood that for less severe circuit controlling conditions the permanent blowout magnet may be omitted, and also when practicable an electromagnetic blow-out coil connected in the switch circuit may be used instead oi' the permanent magnet.

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 modiilcations may be made, and I there,- fore 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. A switch comprising an operating member, a support, means pivotally mounting said member on said support for pivotal movement between `open and closed circuit positions, a handie on said member, a switch contact, a conducting strip supporting said contact, a projection on said operating member forming a bearing for said strip, a spring between said operating member and said support for holding said strip on said operating member, a stationary contact secured to said support in position to be engaged by said movable contact when said operating member is .moved to its closed circuit position, said strip moving on said projection as a pivot against the force applied by said spring to provide a wiping action upon engagement of said contacts.

2. A switch comprising an operating member made of insulating material, a support, means pivotally mounting said operating member on said support in substantially parallel relation therewith for pivotal movement between open and closed circuitpositions, a handle on said operating member, a switch contact, a conducting strip supporting said contact, said Vstrip being provided with an intermediate recess forming a bearing, a projection on said operating member engaging said bearing, a helical compression spring mounted between said operating 76 member and said support, a pin extending` through said`strip and said operating member having a head forming a seat for one end o said helical spring, a member secured to said support having a head forming a seat for the other end of said spring, a second conducting strip secured by said member to said support, a flexible conductor connecting said strips, a stationary contact secured to said support in position to be engaged by said movable contact when said operating member is moved to its closed circuit position. 3. A switch comprising an operating membe made of insulating material, a support, means pivotally mounting said member on said support, a handle on said member, a projection on said member adjacent said pivot, a cantilever spring member adjacent the end of said projection, a link member interposed between said projection and said spring so as to form therewith a snap acting toggle for moving said member between its open and closed'circuit positions with a snap action, a switch contact, a conducting strip supporting said contact, a second spring mounted between said member and said support for holding said strip on said operating member, said second spring being weaker than said rst spring, a second conducting strip, a flexible conductor connecting said strips, conducting means forming a terminal for securing said second spring and said second strip to said support, and a stationary contact secured to said support in position to be engaged by said movable contact when said operating member is moved to its closed circuit position.

4. A switch comprising an operating member, a support, means pivotally mounting said member on said support for pivotal movement between open and closed circuit positions, a handle on said member, a projection on said member adjacent said pivot, a spring member adjacent said projection, a member interposed between said projection and said spring member and forming therewith a snap acting toggle for moving said member between its open and closed circuit positions with a snap action, a switch contact, a conducting strip supporting said contact, a projection on said operating member forming a bearing for said strip, a second spring between said operating member and said support for holding said strip on said operating member, a stationary contact secured to said support in position to be engaged by said movable contact when said operating member is moved to its closed circuit position, said strip moving on said projection as a pivot against the force applied by said second spring to provide a wiping action upon engagement of said contacts.

5. A switch comprising an operating member, a support, means pivotally mounting said member on said support, for pivotal movement between open and closed circuit positions, a handle on said member, a projection on said member adjacent said pivot arranged to engage said support when said member is in its open circuit position, a spring member adjacent the endv of said projection, a link member interposed between said projection and said spring and forming therewith a snap acting toggle for moving said member between its open and closed circuit positions with a snap action, a switch contact, a conducting spring supporting said contact, said strip being provided with a recess forming a bearing, a projection on said operating member engaging said bearing, a second spring between said operating member and said support for holding said strip on said perating member, a stationary contact secured to said support in position to be engaged by said movable contact when said operating member is moved to its closed circuit position, said conducting strip moving on said projection as a pivot upon engagement of said contacts to provide a wiping action.

6. A switch comprising an operating member made of insulating material, a support, means pivotally mounting said member on said support, a handle on said member, a projection on said member adjacent said pivot, a spring member adjacent the end of said projection, a link member interposed between said projection and said spring so as to form therewith a snap acting toggle for moving said member between its open and closed circuit positions with a snap action, a switch contact, a conducting strip supporting said contact, a projection on said member forming a bearing for said strip, a spring mounted between said member and said support for holding said strip on said member, a second conducting strip, a flexible conductor connecting said strips, electrically conducting means forming a terminal for securing said spring member and said second strip to said support, a stationary contact secured to said support in position to be engaged by said movable contact when said operating member is moved to its closed circuit position, said conducting strip moving on said projection as a pivot upon engagement of said contacts to provide a wiping action.

7. A switch comprising an operating member made of insulating material, a support, means pivotally mounting said operating member on said support in substantially parallel relation therewith for pivotal movement between open and closed circuit positions, a handle on said operating member, a projection on said operating member adjacent said pivot arranged to engage said support when said operating member is in its open circuit position, a spring member having one end adjacent the end of said projection, a bolt extending through said support securing the other end of said spring to said support, a link member interposed between said adjacent ends of said projection and said spring and forming therewith a snap acting toggle for moving said operating member between its open and closed circuit positions with a snap action, a switch contact, a conducting strip supporting said contact, said strip being provided with an intermediate recess forming a bearing, a projection on said operating member engaging said bearing, a helical compression spring mounted between said operating member and said support, a pin extending through said strip and said operating member having a head forming a seat for one end of said helical spring, said bolt having a head forming a seat for the other end of said spring, a second conducting strip secured by said bolt to said support, a flexible conductor connecting said strips, a stationary contact secured to said support in position to be engaged by said movable contact when said operating member is moved to its closed circuit position.

JOI-IN F. TRITLE.

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