US414792A - Cut-out for incandescent lamps - Google Patents

Description

NITED STATES PATENT OFFICE.

TURNER D. BOTTOME, OF NEYV YORK, N. -Y., ASSIGNOR TO JOHN B. TIBBITS, OF HOOSICK, NEll YORK.

CUT-OUT FOR INCANDESCENT LAMPS.

SPECIFICATION forming part of Letters Patent No. 414,792, dated November 12, 1889.

Application filed Tune 25, 1889. Serial No. 315,566. (No model.)

To all whom it may concern.-

Be it known that I, TURNER D. BOTTOME, a citizen of the United States, and a resident of New York, in the county of New York and State of New York, have invented certain new and useful Improvements in a Cut-Out for Incandescent Lamps, of which the following is a specification.

This invention relates to an automatic method of cutting out ruptured incandescent electric lamps from alternating-series circuits.

The objects of the invention are to produce a simple, cheap, and effective device for keeping a series incandescent lamp circuit 5 closed when a lamp on such a circuit becomes burned out or ruptured.

I obtain my objects by the mechanism ill ustrated in the accompanying drawings, which form a part of this specification;

Figure 1 illustrates a lamp complete in working order with the cut-out.

Fig. 2 is a diagram of the cut-out. P and N represent the lamp or filament F terminals. 0 and d are the connections with the filament F and the terminal wiresP and N of the lamp L. f A and B are loops, 0f copper or other metallic wire, bent into the shape of the filament F, and are placed normally and preferably in a position just inside of the filament F, Figs. 1 and 4. The distance between each other and from the filament is about one-sixteenth to one-eighth of an inch; but I do not limit myself to any particular distance of sep aration. In the drawings the distance shown may be slightly exaggerated, in order to more clearly show the relative positions of the filament and cut-out loops. As seen from the diagram, A connects with the terminal P at a point shown at 2', while B is similarly connected at j to N.

Fig. 3 shows a filament F combined with the cut-out loops A and B, but out in half, with the ends or edges presented to view.

Fig. 4 is a lamp complete that has been out out.

Therupture of the filament is shown at g, and the fusing-points of the loops A and B are shown fused together at h.

The operation of the cut-out may be explained as follows: The electric circuit normally is through the terminals P and N and through the filament F. A andB simply act as terminals adjunctive to P and N. The filament on becoming ruptured causes an arc to be formed at such rupture. The distance may not be over one one-thousandth of an inch at first, but it quickly becomes greater. and increases in lengthsay to one-fourth of an inch-but the terminal or cut-out loops A and B are only one-sixteenth of an inch apart or so, and a similar distance from the filament, or a total of three-sixteenths, more or less. A and B are both at all points in the same close proximity to the filament F and to themselves, so that when the distance between the points of the arcing filament exceeds the total distance between the loops A and B and the filament F the are on the filament transfers itself onto the loops A and B,

and the heat of the arc quickly fuses the metallic wires and the molten beads of metal soon come into contact and thereby close the electric circuit at that point.

I am aware that it is generally known that a spark or that a current of electricity will not jump nor form an arc in a vacuum; but such facts hold good only witha perfect vacuum. The commercial vacuum of an ordinary incandescent lamp forms a better conductor by far for electricity than air does, which fact is easily proved from the performance of an ordinary Geissler tube.

Another example is the frequent destruction of an ordinary one-hundred-bolt sixteencandle-power lamp by the current jumping across the terminals inside the lamp, forming an are, which instantly melts down the platinum conducting-wires. This action often happens when the platinum wires are nearly, if not quite, fully one-half an inch apart. This action more commonly happens when the filament in the lamp is nearly used up or disinte- IOO ing a long jump with a low clectro-motive force is the case of an ordinary electric-arc lamp, which may be started up, not by first touching the carbon pencils together, as commonly the practice, but by holding a candle or alcohol flame between the separated carbon terminals. In a short time the current will pass, forming a full are. This isdue to the presence of minute particles of carbon, or even vapor, which is detached by the heat of the flame placed between the carbons. In my case the carbon filament, or a filament composed of a metal and carbon-such. as tungsten and carbon-on being ruptured is volatilized, the vapor occupying the vacuum in the inclosed lamp. The presence of this good conducting vapor, together with the close proximity of the cut-out loops A and B to each other and to the filament F, makes the action quite certain above alluded tonamely, the jumping of a low potential current causing the are from the ruptured filament to transfer to the metallic conductors A and B,

which eventually become fused together,

thereby closing the circuit.

I do not limit myself to any particular form of filament to which to apply the cut-out, because it can be placed and operated with any style or shape filaments, the only necessary condition of success being to follow the lines of the filament closely and to keep the distances uniformly close.

I do not limit myself to simply applying the cut-out to lamps containing only one filament, because it is equally applicable to lamps containing several filaments.

I am aware that cut-outs have been devised and used in which the terminals of the lamp were placed closely together, but sepa 'ated by a thin stratum of either some high-resistance conducting mass or by a non-conductor, such as mica. In either case the operation of the cutout depends on an are being formed which eventually cuts out the lamp by the terminals becoming fused together. In the first case the circuit cannot be broken, because it takes the path of the high-resistance body, which soon fails to be a high resistance and causes the lamp to be short-circuited or cut out. other case the potential of the current must become of such an electro-motive force as to enable the current to puncture the nonconducting medium and form an arc.

IVhat I claim as new and original is as follows:

1. An alternatingcurrent cut-out consisting of two metallic loops electrically connected to the terminal wires of a filament and placed in close proximity to each other and the filamentalong its entire length, each loop corresponding in shape to the said filament, substantially as shown and described.

2. An alternating-current cut-out consisting in an incandescent-lamp filament and two metallic loops of the same shape as the filament, one loop being electrically connected to one and the other loop to the other terminal of the filament, and all placed closely together, as shown, and for the purpose d escribed.

Signed at NewYork, in the county of New York and State of New York, this 15th day of Hay, A. D. 1889.

TURNER l). BO'PJOME.

Witnesses:

EMIL REINER, Louis H. Zocnna.

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