US559863A - Electric-arc lamp - Google Patents

Description

(No Model.) 4 Sheets-Sheet 1".

S. E. NUTTING. ELECTRIC ARG LAMP,

No. 559,863. Patented May 12, 1896.

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S. E. NUTTING. BLBGTRIG ARG LAMP.

No. 559,863. `Patented May 12, 1896.

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ELECTRIC ARG LAMP.

No. 559,863. Patented May 12, 1896.

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Patented Ma 2, 1896.

midi/M52? .PHUTD-UTHUWASHIN GTDNJT C UNITED STATES PATENT OFFICE.

SAMUEL E. NUTTING, OF OI'IIOAGO, ILLINOIS.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 559,863, dated May 12, 1896.

Application filed October 18, 1898. Renewed October 14, 1895. Serial No. 565,672. (No model.)

To @ZZ whom, it' nza/y concern.-

Be it known that I, SAMUEL E. NUTTING, a citizen of the United States, residing at Ohicago, Illinois, have invented certain new and useful Improvements in Electric-Arc Lamps, of which the following is a specification.

The object of my improvements has more especial reference to the perfecting of arelamps in which a constant-potential circuit is employed; and my invention consists in ihe features and details of construction hereinafter described and claimed.

In the drawings, Figure l is a front elevation of myimproved arc-lamp Fig. 2, a front elevation of a vertical section of the lower portion of the lamp; Fig. 3, a front elevation of the upper portion of the lamp with the casing removed and a portion broken away; Fig. 4, a front elevation of the devices employed for regulating the amount of current that shall pass through the shunting-circuit, hereinafter described; Fig. 5, a front elevation of a vertical section of a portion of the upper end of the lamp-frame with some of the parts in place, taken in line 5 of Fig. G Fig. a plan view taken in line G of Fig. 5, viewed from below; Fig. 7, a section taken in line 7 of Fig. G, and Fig. S a diagrammatic view showing the circuits.

In the description of my arc-lamp I shall describe particularly only those things which are intended to be the subject of claims and give but a general description as to the other parts, as for the purposes of this case I deem it unnecessary to describe minutely all of the parts represented in the drawings. In describing an arc-lamp in which a constant-potential circuit is employed, embodying my improvements I shall begin with th ebottom portion of the lamp and proceed to the other parts in their order.

I inclose the arc-drawing magnet Ain a tube or case A. The arc-drawing magnet is coiled around a spool or thimble CL, which is provided with an enlarged head at its bottom ct. At the lower end of the case is arranged a dash-pot A2, provided with a piston a?, resting on the coiled spring A3, which tends to lift the piston, with its piston-rod ai, to the highest limit allowed. rIhe core of the magnet I3 terminates in a carbon-holder l), in which the lower carbon is held in place. I arrange on the core a cap I5', which surrounds the top of the case A and serves as a cover to prevent dust and other foreign substances from getting in. Vhenever the current from any cause becomes weakened-as,for instance, from the presence of too great an arc, owing to the too slow feeding of the upper carbon-the coiled spring lifts the piston in the dash-pot until it comes against a wire or contactpiece Z1', adapted to form a portion of a shunt-circuit around the arc, as hereinafter described.

In order to feed the upper carbon, I arrange in a case at the top of the lamp a carbonholding rod C, provided with teeth, as shown in Fig. I arrange in proper position with reference to it a disk of softenable substance O. This disk is mounted on a shaft or spindle, which carries a gear c, whose teeth engage with the teeth 011 the carbon-holding rod, so as to gear them together, by which I mean a connection causing them to move in unison. A heating-pin c extends into the disk a desired distance, so as to hold the disk from rotating under the stress of the weight of the upper-carbon holder and carbon until it has been heated enough to melt or soften the substance of the disk, so as to melt its way through the same. This pin is heated by the wire D of a shunt-circuit, a portion of which is coiled around the same a sufiicient number of tim es to insure its becoming heated by the passage of the current. The wire of the shunt-circuit after leaving the pin passes into a spring E, which in the normal operation of the lamp 'is held out by a sliding rod e, on which the heating-pin is mounted. This in the normal operation of the lamp causes the spring E to contact or rest against a spring E, which thus forms part of the circuit. The wire passes from the spring E through a number of turns F, which form the principal resistance. At different points wires f lead from the turns to contact-points f. These contact-points are arranged so as to be brought into contact one at a time with a contact-arm Gr, mounted on a bent or coiled tube G, filled with a fluid sensitive to changes in the temperature, so as to contract or expand with them. As the bent tube is contracted or expanded it moves into contact with one or an- IOO other ot the contact-points f', and as one or another is brought into contact with it a greater or a less number of turns in the wire of the shunt-circuit has to be traversed by the current before it can pass from one terminal to the other.` Oii course it will be understood that in setting the lamp the contact-arm G will be arranged in contact with the particular contact-point f that will insure the desired amount of current through the shuntcircuit, and so that a greater or a less amount of current will be caused to pass through the shunt-circuit as the temperature may rise or fall, thus insuring a constant feed of the upper carbon through the maintenance of the requisite amount oi heat in the heating-pin to cause it to melt through the disk with a constant rate of speed whether the temperature be high or low. Then for any reason the upper-carbon holder and carbon are prevented from descending-as, for instance, through accident or the intervention of foreign matter between the teeth of the carbonrod and the gear-the heating-pin continuing to melt the softenable substance will be moved through the same by the pressure of the spring E against the end of the sliding red on which it is mounted. This will go on until the spring E has moved away from the spring E', as shown in Fig. G, when the shunt-circuit will be opened and the current cease to heat the pin in the disk. This protects the pin from becoming overheated, as well as waste of the softenable substance forming the disk. Vhen the upper carbon fails for any reason to descend with its proper and normal movement, the current becomes weakened through the lengthening of the are. This weakens the action of the electromagnet and permits the coiled spring A3 in the dash-pot to gradually move the piston a2, carrying the lower carbon upward. Before the piston reaches the upper end of the dash-pot, at which time the lower carbon could be carried no higher, it comes in contact, as already said, with the contactpiece Z1. This causes a portion of the circuit to pass through the wire II to the contactpoint f', which is in the shunt-circuit, with the least resistance, though it need not necessarily be the contact-point of least resistance; but it must be one of. less resistance than the maximum. This has the same effect as if the contact-arm G were brought against the same contact-point, causing a greater amount of current to pass through the shuntcircuit, and thus causes the heating of the pin in the disk to a greater extent, so that the disk will be more rapidly melted and the upper carbon more freely fed downward. This again shortens the arc and causes an increase ot current in the electromagnet until the n ormal condition has been restored, when the piston a2 has been moved out of contact with the contact-piece b and the lamp operated as before the difficulty had occurred.

lVhat I regard as new, and desire to secure by Letters Patent, is-

1. In constant-potential arc-la1nps,the combination of an arc-drawing magnet, a shuntcircuit around the are, and means operated by the magnet for varying the resistance of the shunt-circuit around the are, substantially as described.

2. In constant-potential arc-lamps,the combination of an arc-drawing magnet, a shuntcircuit around the are, a contact-piece adapted to form a part of the shunt-circuit, and a part connected with the negative side of the main circuit which moves against the contact-piece and brings it into the shunt-circuit as the arc becomes lengthened and before it breaks, whereby the resistance oit' the shunt-circuit is reduced and the feeding of the upper carbon accelerated, substantially as described.

3. In constant-potential are-lamps,the combination of an upper-carbon holder, a disk of softenable substance geared with the carbonholder, a shunt-circuit around the are closed during the descent of the carbon-holder, and means engaging such circuit and the disk for opening the circuit when the upper-carbon holder ceases to descend, substantially as described.

4. In constant-potential arc-lamps,the coinbination of an upper-carbon helder, a disk of softenablc substance geared to the carbonholder, a pin electrically heated engaging the disk, a sliding rod on which the pin is mounted, a spring forming a portion of a shunt-circuit around the arc closed during the descent of the carbon-holder and adapted to bear against the end of the sliding rod and force the pin through the disk when the descent ol' the carbon-holder ceases until the circuit of which the spring forms a part is opened, substantially as described.

5. In constant-potential arc-la1nps,lhe combination of an upper-carbon holder, a disk of softenable substance geared tothe carbonholder, a pin electrically heated engaging the disk, a shunt-circuit around the arc having a portion of its wire wound around the pin for heating it, a sliding rod on which the pin is mounted, a spring forming a portion of a circuit closed during the descent of the carbon.- holder and adapted to bear against the end of the sliding rod and force the pin through the disk when the descent of the carbon-holder ceases until the circuit of which the spring forms a part is opened, substantially as described.

SAMUEL NUTr ING IVitnesses:

SAMUEL E. I-IIBBEN, THOMAS F. SHERIDAN.

IOO

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