US522332A - Mohn van vleck - Google Patents

Description

Patented July 3,1894.

.l.| v W I J. VAN VL K'. ELEGTRIGA SWITCH.

I l I I i m i i g I um I i i X E I g I sf b a B) MW. W

- 7 26,4 ATTORNEY.

UNITED STATES PATENT OFFICE.

JOHN VAN VLEOK, OF NEW YORK, N. Y.

ELECTRIC SWITCH.

SPECIFICATION forming part of Letters Patent No. 522,332, dated July 3, 1894;

Application filed May28,1894. Serial No. 512,595. (NomodelJ To all whom it may concern..- i I Be it known that, I, JOHN VAN VLECK, of

the city, county, andState of New York, have invented a new and useful Improvement in- -Sw1tches for Electric-Lighting Circuits, of

which the following is a specification.

My invention is an improvement in switches designed for use in connection with the threewire system ofdistribution, so arranged that circuit through the "neutral cond uctor is broken after and made before it is established through the positive orjnegative conductors.

hereinafter be more particularly pointed out.

In the accompanyingdrawings Figure 1 is a plan view of my switch. Fig. 2 is a side elevation with the coverin section. Figs. 3

I and 4 show two forms of contact fingers. Fig.

5 illustrates diagrammatically the ordinary arrangement of lamps on a three-wire system. Similar letters of reference indicate" like parts.

The form of switch to which my invention is applied is one which is well known and in common use. Hence only a brief description of its parts is necessary.

porcelain or other insulating material.

At the center of the "base A is secured a metal rod, B, which is surrounded by a sleeve, 0, of porcelain made in the shape here shown that is, it is six-sided; Three sides, a, b, c, are covered with plates of conducting material. The remaining sides are uncovered. The post B is turned by the handle E against the action of the coiled spring F. On this post is a pin, G, which enters a re'ce'ssin the upper portion of the sleeve-O.

Supported upon the base A are three pairs of metallic supports, H H, I I and J J, each provided with'an opening, as at K, for the reception of the circuit wires, and withscrews, as L, for clamping said wires in said openings.

In Fig. 1 the neutralwire dis shown clamped in the support 11 and H. The wire eis clamped in the supportsJ and J and the wire f in the supportsI and I. From each support extends a contact finger'bearing upon the periphery i of the sleeve 0. Thus, from the support J there extends a metal contact finger, M, and from the support'J', a metal contact finger, M. The finger M is therefore above the finger M, and is separated therefrom,

Fromthe support I extends a finger, N, which is above the finger N extending from the support-I, and from the support H extends a finger, 0, above the finger O extending from the support II. It follows, therefore, that when all of the several fingers rest upon the metal plates 0. b c of the sleeve 0, circuit is made through the switch, and the current passes from J to J by way of the fingers M M and plate a, from I to Iby way of the fingers N N and plate 0 and from H to H by way of the fingers O O and plate I). This is the arrangement of the switch when the current is turned on. 7

In order to turn the current ofi, the handle E is turned to the right of thedrawings, Fig. 1, so rotating the post B and movingthe pin G in its recess to bear against the sleeve 0, seas to carry said sleeve with it in its rotation. Then, as the sleeve 0 is rotated, the metal plates 01. b 0 move from beneath the tingerswhich rest upon them, and the fingers fall upon the intermediate portions of the sleeve 0, which, as already stated, present a I surface of insulating material. Therefore cir- A is the base, circular in form and made of i M, N N'and O O.

jcuit is broken between each pair of fingers M The difference between the construction above detailed and that already known resides in the fact that in the old form of switch the sleeve 0 has but four sides with but two plates of metal thereuntoapplied, and there are but 'two pairs of supports and contact fingers instead of three pairs of supports and contact fingers, as inmy aforesaid construction. It will therefore be apparent that my switch as above described is especially designed for a'three-wire system of distribution.

Now, what I propose to accomplish by my invention is to prevent a'current of any kind I from passing by wire e to wire f, and vice Fig. 5, I show seven lamps in parallel between the wires d and e and d and f. But suppose that the conditions of the circuit were such that, while seven lamps existed between (Z and e, but one lamp, 9, existed between cand f. Then, instead of the current which feeds the seven lamps between at and 6 coming back by way of the neutral wire (1, all of it, if the switch at 72- in said wire were open, would pass through the lamp g, probably destroying the filament or doing other injury. It is clear that this could not happen if the circuits in e and f were broken before interruption was made in the wire (1. Conversely it is clear that the same consequences would happen if the circuit was closed through c and f before it was closed through d. What I do, therefore, is to arrange the switch, the construction of which I have before detailed, in such a way that circuit is made through the neutral wire cl before it is made through the wires 6, f and broken in (Z after it is broken in the wires (2, f. This is done in the following manner: The fingers M M and N N are all alike-that is, all of the same length and general construction. Because they are of the same length and operate at the same time, circuit is made and broken in the wires cand f simultaneously. The fingers O and 0, however, are diiferently made, and the preferable construction for each of them is shown in Fig. 4. Each finger is slit lengthwise, as shown at P, and thus is composed of two parts, one of which, Q, is longer than any one of the fin gers M M, N N, and the other part, B, is shorter than any one of the fingers M M N N. I have indicated this in Fig. 4G by drawing on the side of said figure aline, 11 7', which represents the length of any one of the fingers M M or N N in comparison with the lengths of the parts R Q of the finger 0'.

Now considering the parts as they appear in Fig. 1, it will be obvious that as the sleeve 0 is turned to the right by the handle E, the fingers M M, N N and the parts R of the fingers O 0' will all leave the contact plates before the parts Q of the fingers O 0; this simply because the parts Q are longer than the other fingers. Therefore, although circuit is broken through the wires f and 6, it remains closed through the neutral wire at until after the part Q of the fingers O 0' pass from the contact plate I); therefore, in breaking the circuit through the whole system, it is obvious that I interrupt the circuit in the wires 2 and f before I do so in the wire d. Now considering the fingers as all resting on the uninsulated intermediate sides of the sleeve 0, and that the handle E be turned still to the right for the purpose now of making the circuit through the system. Plainly the short contact R of the fingers O 0 will pass from the uninsulated portion of the sleeve 0 and meet the plate a before the longer portion, Q, of the fingers O O and before the longer fingers M M, N N. Therefore circuit will be established through the neutral wire cl before it is establishedthrough the Wires 6 and f.

It will be seen that these results are accomplished without changing the ordinary and well-known operation of the type of switch here illustrated, and therefore involve no complication of the device whatever, while greatly increasing its value. In Fig. 1 I have shown the fingers as made of laminated plates of metal, and it will be understood, therefore, that each plate of the three here shown as composing one finger O or O is formed in the manner shown in Fig. 4.

As a modification in the construction of the fingers O and O I may make them as represented in Fig. 3, each finger being then composed of three plates of metal, lm, of which m is similar in length to the part R of the form of finger shown in Fig. 4 and 7c and Z to the part Q, of the aforesaid form of finger. The curved face of the end of the finger meets the curved side of the sleeve 0, as shown in Fig. 1. Obviously the same results already detailed will be produced by a finger of this shape, the part m first meeting the plate on the sleeve 0 in making contact, and the parts kl leaving that plate last when contact is broken. The apparatus is provided with the ordinary form of cover, as shown at S, Fig. 2.

I claim- 1. In combination with a three-wire distributing system, three pairs of contact fingers respectively connected to the terminals of each conductor, a rotary support, and three circuit-closin g plates on the periphery thereof with each of said plates each pair of fingers makes contact; the fingers connected with the neutral conductor of the system being of such length relatively to the fingers connected with the other two conductors as that when said contact plates are moved by the rotation of said support into contact with said fingers, circuit shall be closed through said neutral conductor before it is closed through the remaining conductors, substantially as described.

2. In combination with a three-wire distributing system,three pairs of contact fingers respectively connected to the terminals of each conductor, a rotary support, and three circuit-closin g plates on the periphery thereof with each of said plates each pair of fingers makes contact; the fingers connected with the neutral conductor of the system being of such length relatively to the fingers connected with the other two conductors as that when said contact plates are moved by the rotation of said support out of contact with said fingers circuit shall be broken through said neutral conductor after it is broken through the remaining conductors, substantially as described.

3. The combination in aswitch for electriclighting circuits of a base A, a rotary support, 0, thereon, having contact plates, at b c, 011 its periphery, and three pairs of independently-supported fingers, M M, N N, O

IIO

0, each pair of said fingers being arranged to bear upon one of said contact plates; the fingers O 0 being of diiferent length from the fingers M M and N N.

4. The combination in a switch for electriclighting circuits of a base A, a rotary support, 0, having contact plates, or b c, on its periphery, and three pairs of independentlysupported fingers, M M, N N, O 0, each pair of said fingers being arranged to bear upon one of said contact plates; the fingers O 0 having a portion greater in length than the fingers M M, N N. v

' 5. The combination in a switch for electriclighting circuits of a base A, a rotary support, 0, having contact p1ates,a b c, on its periphery, and three pairs of independentlysupported fingers, M M, N N, O 0, each pair of said fingers being arranged to bear upon one of said contact plates; the fingers O O 20 having a portion less in length than the fingers M M, N N, substantially as described.

JOHN VAN VLECK.

Witnesses:

M. Boson, H. R. MOLLER.

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