US1785068A - Electric switch - Google Patents

Description

Dec. 16, 1930. T. A. BOTH 1,785,068

' ELECTRIC SWITCH Filed Dec. 8, 1926 Patented Dec. 16, 1930 UNITED STATES PATENT OFFICE TON J'ES A. BOTH. OF STRATFORD, CONNECTICUT, ASSIGNOR TO THE CONNECTICUT ELEC- TRIC MANUFACTURING COMPANY, OF BRIDGEPORT, CONNECTICUT, A CORPORATION 1 OF CONNECTICUT ELECTRIC SWITCH Application filed December 8, 1926. Serial No. 153,287.

This invention relates to electrical switches, particularly to a switch of the snap acting type, and has for an object to provide an 1mproved structure, especially for mounting the movable switch'contact, which will be much simpler in construction andmay be manufactured at a less cost and which will be much less likely to break down and form a short or ground than will the structures now generally employed.

With the foregoing and other objects in view, I have devised a switch construction some of the preferred forms of which are illustrated in the accompanying drawing forming a part of this specification. In this drawlng,

Fig. 1 is a vertical section through the body of a switch showing the switch mechanism in side elevation, and with portions broken away y to more clearly show the construction.

Fig. 2 is a transverse section substantially on. line 22 of Fig. 1 omitting the insulating body.

Fig. 3 is a side elevation of the movable switch contact and the mounting therefor on an enlarged scale, a portion being broken away to show the means for attaching the contact.

Fig. 4 is a front elevation thereof looking from the right of Fig. 3.

Fig. 5 is a detail section substantially on line 55 of Fig. 3.

Fig. 6 is a view similar to Fig. 3 showing a slightly difl'erent construction and means for mounting the contact.

Fig. 7 is an elevation looking from the right of Fig. 6.

Fig. 8 is a detail section substantially on line 88 of Fig. 6. 1

Fig. 9 is a side elevation of the movable switch contact. and its support, showing anthrough the tact taken substantially on line 12-12 of- Fig. 14.

Fig. 13 is a section thereof substantially on line 13-13 of Fig. 12, and

Fig. 14 is a front elevation and a section of the contact line 14-14 of Fig. 12.

Referring to Figs. land 2 the switch mechanism is mountedin the usual body 15 made of insulatingv material, such as porcelain. which carries the stationary contacts 16 and 17 to which the leads, not shown, from the house wiring system may be connected by the binding screws 18. The switch mechanism proper is mounted on a yoke 19 to which the body 15 is connected and by which the device is mounted in the wall outlet box in the usual manner. The yoke has spaced side members 20 extending into the chamber in the body and forming a frame or mounting for the movable elements of the switch. These side members each has a notch or shoulder 21 in which the movable switch contact supporting member 22 is mounted for rocking movement. In the present construction this member comprises a flat plate having an opening 23 therethrough arranged with the edges 24 on one side of this opening resting in the notches 21. Pivotally mounted at 25 is a rocking lever 26 which has a projecting handle 27 either of metal or insulating material extending usual opening in the cover plate for operation of the switch. This lever includes a. plate 28 having stop shoulders 29 at the opposite ends thereof to engage the inner wall of the yoke to limit the movements of the lever in opposite directions, and this plate has a notch 30 in which is seated one end of a compression spring 31, the other end of the spring engaging 9. lug 32 on the opposite edge of the opening 23 in the support 22. It will be apparent that as the lever is swung up and down on its pivot the connection with the of the mounting substantially on spring by the notch 30 will swing that end of "the spring back and forth through the plane of the plate 22. During the movement from the lateral positions to the plane of this plate the sprlng is compressed, and as soon as the spring passes through the plane of the plate the force of-the compressed spring will swing the plate in the opposite direction about the pivot edges 24 and shift the position of the switch contact member 33 carried by this plate, and will thus shift it to and from eng azigement with the stationary contacts 16 and l 7 At the present time the common practice is to make the switch contact supporting plate 22 of metal, and the switch contact member corresponding to the member 33 is secured to this support by suitable rivets. It will be apparent that the switch contact must be insulated from this support, and the usual prac' tice is to use insulating discs or washers on the opposite sides of the plate and between the plate and the contacts, and also to use in sulating washers about the rivets where they pass through the contact. It will be obvious that under this arrangement the insulation for the rivets is covered up where it is out of sight and is difiicult to inspect, and besides the space between the metal support and the contact is not great. Therefore, considerable difiiculty is experienced by the insulation breaking down forming shorts or grounds. Furthermore, such a construction is expensive to assemble.

I have overcome these difficulties in the present construction by forming the movablecontact support 22 of a plate of suitable insulating material and so forming the switch contact 33 that it is directly connected and mounted on this support. By this arrangement there is no danger of the insulation breaking down forming shorts or grounds to the switch mounting, and the connection is open where it may be easily inspected. Furthermore, the structure is greatly simplified so that it may be manufactured and assembled I have found that the article known in the trade as laminated bakelite is very satisfactory for this support, the term -bakelite being used to indicate any of the phenolic condensation products of the type of which the true bakelite is only a specific example. This article is composed of several sheets of fabric, usually cotton or linen, covered on both sides with the phenolic condensation product which is then pressed together under high pressure and with the application of heat. When cool the article is very hard and tough, and I have found that the wearing of the edges 24 in the notches or shoulders 21 is no more, and is in fact less. than where metal is used. In the dwrawings I have shown several specific ways of mounting the movable switch contact 33 on the insulating plate or support 22.

In'Figs. 3, 4 and 5 the contact 33 is composed of a pair of spring metal plates 34 whiclr'extend transversely of the plate 22 and have. lugs 35 which are bent laterally to engage the opposite sides of the insulating plate 22 and receive one end thereof between them. The. elements are then secured to the plate by means of a rivet 36 passed through these lugs and the plate.

In Fig. 6 to 8 the switch contact member comprises two spring metal plates 37, and

the support 38 corresponding to the supporting member of Fig. 1 to 5 is provided with spaced openings 39. The contact plates 37 each have a palr of lugs 40 which are passed through these openings and merely bent over against the opposite surface of the support as indicated. It will be obvious that this is a very simple construction which may-be easily manufactured and assembled and which will rigidly mount the contact on the support.

In the form' shown in Figs. 9 to 11 the switch contact comprises a pair of metal plates 41 which at their central portion have lugs on the opposite sides thereof bent laterally transversely of the plane of the plates. The lugs 42 on the inner plate are somewhat shorter and closer together than the lugs 43 'on the outer plate so that they may be nested together, as shown in Fig. 11. The end of the insulating support 44 is seated between the lugs and has openings 45 therethrough into which the free ends of the lugs 43 are bent to securely fasten the contact to the support.

In Figs. 12 to 14 the insulating support 46 corresponding to the insulating supports of the other forms has adjacent one edge an oblong opening 47 which is contracted at its opposite ends to form inclined side edges 48. The switch contact member comprises two spring plates 49 which are of a width at their centers to pass through the opening 47 and are provided on the opposite edges thereof with notches 50. These plates are bowed somewhat and arranged with the concave sides together as shown in Fig. 13, so that their central portions tend to separate. These plates are inserted in the opening 47 by pressing the central portions together, then when in proper position they are released and the central portions will separate under the resiliency of the members to the position of Figs. 13 and 14, which will cause the inclined side edges 48 to seat in the notches 50 in the contact plates. This will secure the plates to the support, but they may be easily removed by reversing this process, that is, by pressing the central portions together to remove the notches 50 from the inclined wall 48 and then sliding the contacts from the opening.

invention is not limited to this particular shape of the support, as it will be obvious it may be made in different shapes depending on the type of switch mechanism which is to be employed. Whilein Figs. 4, 7,10 and 14, I have shown a single switch contact mounted on this support it will be obvious:

that a similar switch contact may be secured to the opposite end of this support for use in a double pole switch. In Fig. 10 I have shown the support 44 as provided with a separate set of openings45 for mounting this second switch contact, and, of course, the same feature may be used for any of the other supports. I wish to particularly emphasize the fact that the rocking and movable support for the switch contact member is of itself composed of insulating material and that the switch contact member is directly secured to and mounted on this support, doing away with the necessity of providing separate insulating elements as is required for the constructions now generally employed for insulating the contact member from the metal support, and also removing the liability of a short or ground from the switch contact to this support.

Having thus set forth the nature of my invention, what I claim is:

1. In an electric switch, a flat support comprising a plate composed of insulating material mounted to rock in a mounting about an edge of the plate as a pivot in a direction transverse the plane of the plate and having a transverse opening, a switch contact member mounted directly on said support to move therewith in a plane substantially normal to the plane of the plate, means extending into said opening to secure the contact directly to said support, and means for rocking the support. v

2. In an electric switch, a frame having shoulders, a flat support composed of insulating material having edges engaging said shoulders for rocking movement in said frame about said edges as a pivot and in a direction transversely of the plane of the support, said support being provided with a transverse opening, a switch contact member directly connected to said support to move therewith in a plane substantially normal to the plane of the support, means in said opening to secure the contact to the support, and means for rocking said support.

3. In an electric switch, a frame, a contact support comprising a flat plate composed of insulating material mounted for rocking movements in said frame in a direction transversely of the plane of the plate and provided with a transverse opening, a switch contact member mounted on said support to move therewith and extending from the plate in a plane substantially normal thereto, means in said opening to secure the contact to the plate, and means for rocking the support.

4. In "an electric-switch, a movable contact support comprising a'flat plate of insulating material mounted to rock about an edge thereofin: a direction transverse the plane iiof thei'plate,fia switch contact'member comprising a spring plate having lugs passing through the. plate: and folded. against-the plate to'secure the contact thereto, and means for shifting the plate to operate the switch;

' 5. In anelectric switch, a movable contact support comprising a plate of insulatingmaterial provided with an opening therein, a switch contact member comprising asubstantially flatmember extending from opposite sides of theplate in a plane substantially normal to the plane of the plate and having a lug passing through said opening and folded over on the opposite side to secure said member to the plate, and means for shifting the plate to operate the switch. I

6. In an electric switch, a movable contact support comprising a plate of insulating material havin an opening therein, a switch the plate and having a pair of spaced openings, a switch contact member extending transversely of the plane of the plate and having lugs extending through said openings and folded over against the surface of the plate to secure the member thereto, and

means for moving the plate to operate they switch.

8. In an electric switch, a movable support comprising a plate of insulating material having a pair of spaced openings, a switch contact member comprising a pair of metal plates arranged side by side and extending transversely of the support, said plates eac having lugs extending through said openings and folded over against the surface of the support to secure the plates thereto, and.v

means formoving the support to operate the switch.

9. In an electric switch, a frame having spaced side members provided with notches,

a movable switch contact support comprisinga plate of insulating material having an opening therethrough and with the edges at one side of the opening seated in the notches to form rocking pivots for the plate, said plate being also provided with a second opening, a switch contact member extending transversely of said plate and having securmg means integral therewith to enter said second opening and engage the plate to secure the contact member thereto, and means transverse for moving the plate to operate the switch.

10. In an electric switch, a frame, a contact support comprising a flat plate composed of insulating material mounted forrocking movement in said frame in a direction transversely of the plane of the plate and provided with a transverse opening, a switch contact member mounted on said support to move therewith and extending from the plate in a plane substantially normal thereto, means integral with said contact member extending into said opening to secure the contact to the plate, and means for rocking the support.

In testimony whereof I affix my signature.

TONJES A. BOTH.

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