US488899A - Non-sparking electric switch - Google Patents

Description

(N0 Model.)

G. E. PAINTER. NON SPARKING ELECTRIG SWITCH.

No. 488,899. Patented Dec. 27, 1892.

Zin 0/ UNITED STATES PATENT OFFICE.

GWYNNE E. PAINTER, OF BALTIMORE, MARYLAND.

NON-SPARKING ELECTRIC SWITCH.

SPECIFICATION forming part of Letters Patent No. 488,899, dated December 27, 1892.

Application filed March 11, 1892. Serial No. 424,540. (No model.)

To all whom it may concern.-

Be it known that I, GWYNNE E. PAINTER, a citizen of the United States, residing at Baltimore, in the State of Maryland, have invented certain new and useful Improvements in Non-Sparking Electric Switches, of which the following is a description, reference being had to the accompanying drawings, and to the letters and figures of reference marked thereon.

My invention relates to electric switches and particularly to that class of switches used upon incandescent circuits.

The object of my invention is to prevent the destructive sparking at the contacts occurring upon the making and breaking of the circuit. Broadly speaking, I accomplish this end by adding a contact to those usuallyemployed which makes circuit before the main contacts come into use and breaks it after they have gone out of use so that the sparking,inevitable in all circuit-breaking switches, is confined to the added, or, supplemental, contact. This is preferably a thrust contact and not a rubbing or dragging one. The reason for this is that where rubbing contacts are used the sparking roughens the contact surfaces and an unnecessarily strong effort is required to work the switch because of the friction caused thereby.

I have illustrated and described my invention in combination with an electromagnetic two-pole switch intended to be used upon chandeliers and in places not easily accessible. The device is more appropriately applicable to such a switch, as its perfect operation depends upon the eiiiciency of the electromagnets which are the actuating power, and they will not work well, sometimes not at all, if the contacts are roughened by sparking and the friction between them consequently much increased.

In the drawings-Figure 1 is an end view of a switch such as described above, with some of its parts broken away. Fig. 2 isasectional View taken on the line oc-w of Fig. 1. Fig. 3 is an enlarged detail of the device shown in Fig. 1. Fig. 4is a detail modification. Fig. 5. is a view in diagram showing the circuit connections.

As seen in Figs. 1 and 2, a plurality of electro-magnets M, M, are mounted upon a suitable base X, in any convenient manner, and this base is not more particularly described as it forms no part of the present invention. A rocking lever L, is pivoted above the magnets M, and armatures A, A, are fixed to it in proximity to the poles of said magnets.

In the end view in Fig. 1, one pair of the magnets M, is shown and the armature on one end of the lever under the influence thereof. Fig. 2 being in section, only one of each pair of magnets is shown.

The rocking lever L, is provided with insulating blocks I, 1, which extend beyond the ends of said lever and are securely attached thereto. Upon these blocks, or inserted into them, are conducting blocks 0, O, which are placed at the upper edge of one and at the lower edge of the other of the blocks 1, I, so that in one position of the lever both pairs of the contacts E, E, will be in contact therewith and in the other out of contact, so that the circuit will be broken on both sides, that is, both positive and negative, at one movement of the lever. One of the contacts E, in Fig. 1,is broken away to show the application of my anti-sparking device which is fixed to a bracket B, and to which one of the spring contacts E is attached. The bracket B, is fixed in any suitable manner to the base X, that supports the electro-magnets M, M, and extends upwardly and has an offset 0, at the top. This offset is wide enough to project beneath the contact block I, and it is bored to receive a pin P, which passing therethrough makes a thrust contact with a conductor 0, leading down from the block I, and terminating in a flat head h.

At the outer extremity of the offset 0, is fixedaspring S, which is long enough to reach to and beneath the pin P, to which it is fixed. The spring S, presses the pin P,upward with a constant pressure and its proximity to the conductor 0, may be adjusted by the screw to, so that the moment of its contact with the said conductor is accurately determined. The pin P, does not touch the head of the conductor leading from the contact block 0, except when it is depressed, but must do so before contact is made between the spring contacts E, and the block 0, as otherwise the sparking would take place between the wrong contacts and the device be useless. The range of throw of the supplemental contact or pin P, must be great enough to establish contact before theregular circuit contacts E, on one side of the circuit and maintain it after these main contacts have broken circuit. This can easily be adjusted by means of the screw to.

In Fig. 1, I have indicated the contact surface of the spring contact E, by a dotted line 1, and a comparison willshow that the distance between the said line and the block 0, is less than the throw remaining to the pin P, which is only limited by the spring S, coming into contact with the set screw it. This is also shown in Fig. 3, where neither the contact E, nor the pin P, have completed contact. By a comparison it will be seen that the contact E, represented by the line 1, will not reach the block 0, until after the pin P, contacts with the head h, of the conductor 0. It is of course obvious that the contact E will leave the block 0, before the pin P, breaks contact with the head 71, of conductor 0.

The result of the operation described will be that whatever sparking takes place will be between the pin P, and the head of the conductor c, and the contactsurfaces of the blocks 0, C, and contacts E, E, will remain smooth and offer the least resistance to the operation of the lever Ii, actuated by the electro-magnets M.

Referring now again to Fig. 2, it will be seen that the metallic block upon the insulating block I, is wider than the one upon the block I, and that the contacts E, will therefore complete one side of the circuit before the contacts E do the other. This is, of course, necessaryin order that circuit may be completed and current flow through the supplemental contacts before it does through the contacts E. The pin P, may make contact either simultaneously with the contacts E, or at any time after and before the contacts E. In single pole switches'the supplemental contact would make contact before the single main contact or contacts. The pin P, and conductor 0, with its head 71, could be made removable at small expense and the life of the switch much prolonged.

In Fig. 4 I have shown a modification of my device the principal difference being in using a spiral spring instead of a flat one. Here a short bracket 2', is fixed to the largerbracket B. The bracket t, supports a spring .9, and also serves to guide one end of the pin P.

As shown in Fig. 5 upon a partial depression of the lever L the circuit will be from source through conductor 1, to bracket B, thence through spring S, pin P, thereon, through the head h, of pin 0, to the opposite supplemental contact, bracket, and conductor 2, to translating devices. A further depression of the lever L, will bring the contacts E, upon the block O,and the circuit willbe com pleted through the main contacts.

In the diagram I have shown the supplemental contacts making circuit through the head h, of a single pin 0, but itwill be understood that the operation would be the same if two pins were used, one for each contact and the circuit completed through the block C. One pair of the magnets M,are shown as being operated by a battery Z), through conductors 3, 4, the circuit being controlled by a switch 1). A similar circuit maybe provided to operate the opposite pair of magnets.

It will be understood that the relative area of contact surface of the main and supplemental contacts must be properly proportioned with respect to the current carried as, if the area of the supplemental device be too small, it would be ineffectual.

Many modifications of the details of myinvention might easily be made withoutdeparting from the spirit thereof, and I do not, therefore, confine myself to the precise construction shown.

Having described my invention, what I claim and desire to secure by Letters Patent 1s:-

1. The combination in an electric switch of a rocking lever, means foroperating the same, a contact bar upon each end of thelever, main circuit terminals completing circuit through said bars and a supplemental contact completing circuit in advance of the main terminals.

2. The combination in an electric switch of a rocking lever, means for operating the same, a contact bar upon each end of the lever, main circuit terminals completing circuit through said bars, and two or more supplemental contacts completing circuits in advance of the main terminals.

3. The combination in an electric switch of a rocking lever, means for operating the same, a contact bar upon each end of the lever, brackets supporting the main terminals of the circuit in proximity to said bars, and supplemental contacts upon two or more of the bracke ts completing circuit before the main terminals.

at. The combination in an electric switch of a rocking lever, means for operating the same, a contact bar upon each end of the lever, main circuit terminals completing circuit through said bars and supplemental spring contacts making a thrust contact with the bars and completing circuit through them in advance of the main terminals.

In testimony whereof I hereto affix my signature in presence of two witnesses.

GlVYNNE E. PAINTER.

Witnesses:

G. ALLEN MUELLEN, ALICE O. ILGENFRITZ.

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