US288826A - Electric-arc lamp - Google Patents

Description

2 Sheets-Sheet 1.

(No Model.)

J. T. MCCONNELL.

ELECTRIC ARC LAMP.

No. 288,826. Patented Nov. 20, 1888.

JAW- 951mm Q m. wnhinitm O. C

(No Model.) 2 Sheets-Sheet 2.

J. T. MO OONNELL. ELECTRIC ARC LAMP.

No. 288,826. Patented Nov. 20, 1883.

I I r E 2 "I ll M i v I 1 h 1 i II T v I 'l I F E I I v! LIV c I JV w: f7W,

UNITED STATES PATENT OEEicE.

JOSEPH T. MCCONNELL, OF PITTSBURG, PENFSYLVANIA.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 288,826, dated November 20, 1883.

Application filed July 14,1883.

To all whom, it may concern:

Be it known that I, JosErH T. McGoNNELL, of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Electric-Arc Lamps and I do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same, reference beinghad to the accompanying drawings, which form apart of this specification.

The object of this invention is to provide electricarc lamps with a device which shall operate to cut out the electrodes when the arc becomes so long as to endanger any of the parts, especially the coil of wire in derivation around the electrodes, when the feeding mechanism sticks or in any way becomes irregular in its action and fails to perform its functions properly, when a portion of either electrode disrupts from the body thereof, when either electrode falls from its support, or, in, fact whenever from any cause the circuit through the electrodes of the lamp assumes such a condition as to abnormally absorb the general current, and thus reduce the power of other lamps in the same circuit and tend to destroy its own mechanism; and, further, my object is to effect the relighting of any such faulty lamp the instant its electrodes shall come together, and to effect this instantaneously with unerring certainty.

It is only where two or more lamps are operated in series that the want is felt of any automatic device having the foregoing general character. My aim is to accomplish all the required operations incident to relighting after cutting out by means entirely mechanical, and thereby avoid all the uncertainties of electrical action, dispensing with the necessity of accurately proportioning the parts, and avoid ing the uncertain results of oxidation or bad contacts, and to at the same time effect a reliable and instantaneous relighting of the lamp the moment the electrodes come in contact.

To these ends my invention consists, briefly, in providing a normally-open path of low resistauce around the electrodes and placing therein two points of closure, one of which shall be made by the abnormal movement of (No model.)

the armature of either the usual regulatinghelix or the derivation-helix of high resistance, and the other of which shall be made by the lower electrode and broken by the pressure of the upper electrode thereon. The consequence will be that the by-path established will be mechanically ruptured by the very fact of contact of the electrodes, so that practically there is at any moment only a single path open to the main current.

The invention further consists in the ar rangement and combination of devices for the above and other ends, as hereinafter fully described and claimed.

The invention may be put in practice in a great variety of ways; but I will confine my description to the illustration of one simple form. All the working parts of a form of regulating mechanism are shown in the drawings; but the present invention concerns only so much as relates to the automatic switching of circuits, the remaining parts being shown merely to make clear the relative positions of the mechanisms of the lamp.

Figure l of the drawings is a partly sectional elevation of the upper portion of an arc-lamp, and Fig. 2 a similar but reduced view of the lower portion. In these views the position adopted for illustration is that of normal arc, the operative lever of the mag net system standing in position of normal equilibrium. Fig. 3 is a detail of the cuttingo .it device applied to the armature of the main electro-magnet, showing the position assumed to effect the cutting out of the electrodes.

A is the top plate, and B the bottom plate, the two rigidly connected together by suitable standards or parts. (Not shown in the drawings.) To the plate A are screwed, 011 the respective sides of the center, the main helices O of low resistance in the electrode-circuit, and the high-resistanee helices D in a derived circuit between the positive and negative terminals of the lamp. A bracket, E, attached to the plate A, serves as a pivotal support for a horizontal lever, F, whose ends are respectively connected to the suction-cores a and yoke b of helices O by means of the post 0, Fig. 3, and to the suction-cores (Z and yoke e of helices D in a similar manner. A vibrating lever, f, has one end pivoted to a fixed support, and rests upon a curved surface on le 2 wa es ver F, the other end of the lever f being connected to the standard g, which projects upwardly from the box 71/, which surrounds the toothed carbon-rod G. In the box it is journaled a small pinion engaging the rackteeth on rod G, and on the shaft of this pinion, outside the box 71, is an escape-wheel, t. On standard 9 is pivoted the escapement-anchor it, having the pendulum-bobs Z. A gravitating detent, m, is pivoted on an extension, 02, of box h, and normally engages the wheel t, as shown. By this means the energizing of helices 0 draws up cores a and yoke b and elevates that end of lever F, thus lifting the lever f, and with it box h and its pinion,which, being-locked by detent m after the first movement, lifts with it rod G and establishes the arc. Regulation is accomplished by the action of the derivation-helices D, which, when the arc. tends to become too long, predominate in attraction, and, through the cores (Z and yoke e, pull up that end of lever F and cause the other end of said lever to descend, thus lowering the rod G. The continued attraction of helices D in this manner eventually brings the toe o of detent on against a stop, 1), and momentarily withdraws the detent from wheel t, upon which the weight of the rod G acts as motor and tends to turn it, its speed being then regulated by the momentum-es capement k Z. Thus the proper length of are is maintained.

As the foregoing construction is the subject of a separate joint application to be filed, I will not herein go into details. In such a lamp my invention is applied in the following manner: The helices O are preferably wound on metallic spools, one or both of whose heads (1 are connected directly to the positive binding-post or terminal, as shown, the spools being well insulated from the plate A. The post a is insulated from yoke b, but fitted so that the yoke 12 has a slight vertical play, in order that the initial movement of the cores to and yoke 12 shall not affect the post 0. A metallic plate or washer, r, is attached to the insulated portion of post 0, so as to be under yoke b. IVhen the yoke b is in unattracted position, as in Fig. 3, it rests in contact with the plate 9", as shown. Plate r has a vertical pin, 8, depending from it, and against the pin 8 bears a contact-brush, z, fixed on an insulated post, a, set in plate B of the lamp, so that in all positions of the post a there will be contact between pin 8 and brush it. From the latter an insulated wire, o, passes down along or through one of the side rods of the lamp.

The lower crossbar, H, at the bottom of the lamp, forms, as usual, the support for the lower carbon, I but the carbon-holder K, instead of being fixed, as in all non-focusing lamps, is arranged so as to have vertical play. The metallic socket M receives and guides the stem y of the metallic carbon-holder K, and is insulated from the cross-bar II, as shown, being connected by screws to the insulated washer z, whence an insulated conductor, 1;, passes directly up to the negative binding-post or terminal of the lamp. The wire 1; terminates at the insulated screw N, which screws a spring, P, which extends under the stem y. An insulating-pin, a, in the lower end of stem 3 bears always upon the spring P, and the tension of the latter is such as to steadily hold up the stem y, carbon-holder K, and carbon I, except when the upper carbon, T, is resting on the carbon I. There is then. the additional weight of the carbon T and its rod G bearing 011 the spring P, and it yields. Then the spring P is supporting only the negative carbon I, holder K, and stem 0 it makes contact at c with z, and such position of contact is the position always maintained while the electrodes are separated. The instant, however, that the electrodes come together the contact at c is forcibly opened by the additional weight of carbon T and rod G. hen the lamp is illactive, having no current, the short circuit through c is open, and the normal circuit is then from the positive terminal through helices O, thence by brush (1 to rod G, to carbon T, carbon I, holder K, socket M, washer 2, wire 12, to the negative bindingpost. Helices O are energized, and the first attraction breaks the connection between plate 0' and yoke I), and its further attraction lifts rod G and carbon T and establishes the are. This action lifts the extra weight off carbon I, and spring Pmoves upwardly and makes the contact at 0,- but no circuit exists, because there is a break at another point-namely, at r b. The circuit through the carbons remains as the only one of low resistance for the current to take. Now, if from any cause whatever this circuit should fail or the arc become too long, either the failure or weakening of attraction for cores a and yoke b or the predominant attraction for cores d and yoke 6 causes the lowering of the cores (4 and yoke b, and the contact at 1' b is made. This establishes ashort circuit then from positive bindingpost to q, to a a, to Z, to r s, to t, to a, to o, thencebywireoto spring P, through a to wire 1;, thence to negative terminal, affording a short circuit around the main helices O and the electrodes. As the helices O are cut out through the failure at the are, the contact at r b will remain and reliably maintain the short circuit as long as the carbons are held from contact. Should the defect become self-remedied and the positive carbon T feed down into contact with carbon I, thus bringing the lamp into normal condition again, the instant the weight of carbon T and rod G bears on carbon I the contact at c is broken and the current is transferred into helices O, which instantly attract the cores a and yoke I), thus also breaking the contact at 1- I). In practical operation these two breaks at c and 1- 6 occur at the same time, and my experience has demonstrated that no spark is produced at either point. The instantaneous attraction of cores a and yoke 2) effects the establishment of the are, since the current has no choice of circuits, for the whole current IOC Lil

(leaving helices D out of consideration) must pass through helices O. In this establishing of the arc, both at the first lighting or any relighting, the movement of the parts must be sufficient to allow for the slight rise of the negative carbon due to the elasticity of the spring I; but this play, as well as that of the parts r I), need be but very small, owing to the absence of any tendency to form a spark at the rupture of contact at c or 1' I). The relighting of the lamp is therefore removed out of the uncertain realm of divided electric circuits and relative resistances, and is effected with the absolute precision of mechanical laws. The short circuit established by r I) must unfailingly be broken at the very instant it should be, and at that instant only-namely, when by the de scent of the positive carbon the lamp is restored to an operative condition. In the absence of such restoration the short circuit remains; but I wish it to be understood that the presence of any resistance in said short circuit has no influence whatever on the making and breaking of said circuit or its maintenance, since at no time has the current a choice of circuits. There is but one circuit open at a time. hen one opens the other closes, and vice versa.

IVhile I have shown and described a particular assemblage of devices for the purpose of bringing my invention into practical effect, I by no means confine the scope thereof to any single assemblage or combination, as the mere construction and arrangement of devices may be greatly varied.

I11 the present application, and in applica tion filed July 30, 1883, by myself and Thos. J. McTighe,certain details are shown common to both forms of lamps. I therefore herein disclaim as of this application whatever is shown and describedin said application of myself and Thos. J. McTighe, and not herein specifically claimed.

I claim as my invention 1. In an electric-arc lamp having a feeding magnet in the electrode-circuit, a short circuit around the electrodes, having two breaking-points in series, one adapted to be closed by the weakening of the feeding-magnet or the abnormal strengthening of a higlrresistance derivation-magnet, and the other adapted to be opened by the pressure of one electrode upon the other and closed by their separation, substantially as described.

2. In an electric-arc lamp, a short circuit around the electrodes, providedwithItwobreaking-points in series adapted to be opened at substantially the same instant, as set forth, whereby the formation of a spark is prevented upon opening said circuit.

3. In an electric-arc lamp, the combination, with the lower electrode, of a vertically-movable holder adapted to yield slightly when the upper electrode bears upon the lower, substantially as described.

4. In an electric-are lamp, the combination of a movable lower or negative carbon-holder, a short circuit around the electrodes, and a switch in said circuit adapted to open to the pressure of the upper carbon and to automatically close upon the relief of such pressure, substantially as described.

5. In an electric-arc lamp, the combination, with the lower or negative electrode, a holder therefor adapted to a limited range of motion, and a spring adapted to normally support said electrode and holder and at the same time close a switch, but to yield to any additional weight and at the same time open said switch, sub stantially as described.

6. In an electric-are lamp having a helix in the electrode-circuit, an armature for said helix, and a movable device on said armature, said armature and movable device constituting aswitch in a short circuit around the electrodes and said helix, one of said parts being adapted to open the switch by the electromagnetic attraction exerted upon the passage of current in said helix, substantially as described.

7 In an electric-arc lamp having a helix in the electrode-circuit, an armature, a movable device on said armature, said armature and movable device constituting a switch in a short circuit around the electrodes and said helix, and adapted to close upon the abnormal weakening or failure of current in said helix, a movable lower electrode, and a switch in said short circuit adapted to remain normally closed while an arc exists, and to open upon the impact of the electrodes, substantially as described.

8. In an electric-arc lamp, a main actuating magnet, O, in the electrode-circuit, a lever, F, adapted to communicate the energy of the helix to the electrode, an armature, a b, for said helix, and an insulated post, 0, connecting said armature with the lever, said armature having a slight play, in combination with a short circuit around the said helix, and electrodes passing from the armature to the said insulated post, substantially as described, whereby when current is absent from the helix the short circuit is closed between the armature and post, and when the helix is energized the short circuit is ruptured by the attraction first exerted on the armature.

9. In an electric-arc lamp, the combination of magnet G, lever F, armature a b, insulated post 0, having plate '2', and suitable connec tions, said magnet 0 being in direct circuit with the electrodes, and said armature a b and plater constituting a movable switch in a short circuit around the said magnet and electrodes, substantially as described.

In testimony that I claim the foregoing as my own I have hereto affixed mysignature in presence of two witnesses.

JOSEPH T. McCOXXELL.

\Vitnesses:

T. J. McTrcnn, Tnoams J. Pxr'rnnsox.

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