US478276A - Half to frank a - Google Patents

Description

(No Model.) 2 Sheets-Sheet 2.

W. P. EAYRS.

RHEOSTAT.

L K E I El .2" 9 1G .fi itest: 17221672207".-

f7 /VMM 6. M02

Unrrnn STATES PATENT OFFICE.

IVINSLOIV P. EAYRS, OF NASHUA, NEIV HAMPSHIRE, ASSIGNOR OF ONE- HALF TO FRANK A. MCKEAN, OF SAME PLACE.

RH EO STAT.

SPECIFICATION forming part of Letters Patent No. 478,276, dated July 5, 1892.

Application filed August 3, 1891.

To all whom it may concern:

Be it known that I, WnvsLow P. Earns, of Nashua, in the county of Hillsborough and State of New Hampshire, have invented a new and useful Improvement in Reduction- Switches; and I do hereby declare that the following is a full and exact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon,making a part of this specification.

In the drawings, Figure 1 is a perspective View of a convenient embodiment of my invention. Fig. 2 is a perspective view showing the two parts thereof separately, and Fig. 3 is a diagram illustrating the electrical connections and mode of operation.

Like letters of reference are used to denote like parts in all of the figures.

O is a turret carrying two resistances R and R, shown for convenience of illustration in the form of coils, and is itself rotatable on an axis vertical to the fixed frame D. The base D carries four binding-posts, with their respective contact-pieces M M and N N, M and M being connected with the main line and N and N being respectively connected with the ends of the house-line S S, including the light or lights to be controlled, (indicated by T in the diagram.)

On the disk C, as shown in Fig. 2, are placed two contact-strips E and E, adapted and intended to be always in contact with the contact-pieces M and M, respectively, and connected permanently with the respective contact-points L and L by the heavy wires O and O. The contact-strips E and E are also connected, respectively with the resistance devices R and R. On the same disk, in corresponding positions and respectively opposite the coutact-strips E and E, are placed the two sets of cont-act-pointsF GH and F G H, F, G, and H being connected with the resistance R each at a diiterent pointand F, G, and H being similarly connected with the resistance R, each one of two corresponding points, as F and F, being connected with the same point in its respective resistance, so that the resistance between the contact-strip E- and the contact-pointFshall be substantially equal to the resistance between the contact- Serial No. 401,454. (No model.)

strip E and the contact-point F and so that the resistance between the contact-stripE and the contact-point G shall be higher than that between the same contact-strip and the contact-point F, the effect of this construction being to make the respective resistances between the contact-strips and each pair of corresponding resistance-points substantially equal to each other and higher between the contact-strips E E and each successive pair of corresponding contact-points Normally the course of the current is through contactpiece M, contact-strip E, wire 0, contact-point L, contact-piece N, house-line S S, contactpiece N, contact-pointL,wire O, and contactstrip E to contact-piece M without resistance. If the turret is rotated sufficiently to place contact-pointF on contact-piece N and contact-point F on contact -piece N, the course of the current will then be through contact-piece M, contact-strip E, resistance R, contact-point F, contact-piece N, house-line contact-piece N, contact F, resistance R, contact-stri p E, and contact-piece M, the obvious effect being to throw a previously-determined resistance into both legs of the circuit and to reduce proportionately the candle-power of the light or lights included therein. In the same manner if the contact-point Gin the base of the turret be placed on the contactpiece N another path will be established for the current, a higher resistance thrown into both legs of the circuit, and the candle-power of the light or lights therein reduced proportionately.

Any desired number of pairs of contactpoints can be placed on the disk C and connected with ditferentpointsin the resistances R and R, so that the reduction of candlepower in the light or lights controlled by the device can he graduated in any way or to any extent that may be desired.

The obvious advantages of the reduction device herein described are its simplicity of construction, certainty of operation, non-liability to derangement by wearor ordinary accidents, and the fact that it can be applied and used economically to control a singlelight, as well as to control a group.

It will be understood that I do not confine myself to the particular construction and arrangement shown and described, but that the construction and arrangement may be varied without departing from the principle of my invention.

I claim as my invention- 1. In a device for regulating electric lights, two resistances and contacts therefor, two sets thereof being connected, respectively, with said resistances, corresponding contacts in each set being connected with their respective resistances at similar points, said resistances being respectively always in contact with the legs of a main circuit and said corresponding contacts being movable and adapted to be brought in pairs successively in contact with the legs of a local circuit, substantially as shown and described.

'* 2. In a device for regulating electric lights, the combination of a base carrying contactpieces connected, respectively, with the legs of a main and a local circuit, a support movable upon said base, two resistances carried by said support, two sets of contact-points also carried by said support, each set being connected with one of said resistances, each contact-point therein with a difierent point in the resistance and corresponding points in each set with similar points in each resistance, and contact-strips upon said support adapted to keep said resistances respectively always in contact through contact-pieces on the base with the legs of one of said circuits, said contact-points being adapted to be ance and corresponding points in each set with similar points in each resistance, an (1 contact-strips upon said turret adapted to keep said resistances respectively always in contact through contact-pieces on the base with the legs of one of said circuits, said contactpoints being adapted to be brought by the rotation of said turret successively and in pairs respectively in contact through contactpieces on the base with the legs of the other of said circuits, substantially as shown and described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

WINSLOW P. EAYRS. \Vitnesses:

EDWARD A. GREELEY, IRA F. HARRIS.

Images