US574117A - Henry a - Google Patents

Description

(Nomaden l H. A. SEYMOUR.

ELECTRIC ARG LA MP. y N0. 574,117. -5 Patented Deo. 29, 1896.

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UNITED STATES PATENT OFFICE.

HENRY A. SEYMOUR, OF IVASHINGTON, DISTRICT OF COLUMBIA.

ELECTRIC-ARC LAlVl P.

SPECIFICATION forming part of Letters Patent No. 574,117, dated December 29, 1896.

Application filed .Tune 30, 1896.

T0 tif/ZZ whom, it ntcty concern:

3e it known that I, HENRY A. SEYMOUR, of W'ashington ,in the District of Col u mbia, have invented certain new and useful Improvements in Arc-Lam ps; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to malte and use the same.

My invention relates to an improvement in arc-lamps, and especially to that type of lamps which are operated by alternating currents.

IIeretofore many attempts have been made to produce an arc-lamp for operation with an alternating` current, and while a measure of success has been attained with lamps constructed to burn a short arc no one has as yet succeeded in providing an alternatingcurrent lamp capable of establishing and maintaining a long arc within an arc-inclosi ng globe. It is absolutely essen tial to the establishment of an arc between the two electrodes of an alternating-current lamp that their adjacent ends be first heated to such a degree as will result in the formation of a bridge of conducting carbonaceous vapor across the gap or space between them when separated. Without some provision for heating the adjacent ends of the electrodes when currentis passed through an alternating-current arclamp they will chatter violently for a considerable length of time before it is even possible to establish and maintain a short arc, and this is due to the fact that as a rapidly-alternating current is sent through the cold electrodes the current falls to zero so rapidly that the carbons cannot be maintained separated for a sufficient length of time to insure their being heated to such a degree as will insurethe maintenance of an arc between them. Hence the slight arc formed between the cold carbons is rapidly established and broken, resulting in a rapid and violent chattering of the carbons and regulating mechanism,which continues until the ends of the carbons have become sufficiently heated to insure the production of a conducting bridge of carbon vapor across the gap or space between them, and then, and not until then, is a persisting are established.

The operation of alternating-current arc- Serial No. 597,612. (No model.)

lamps as heretofore constructed has been attended by a constant hissing of the arc and buzzing of the regulating mechanisim'whieh has proved so annoying and objectionable as to have very largely restricted their use.

Attempts have been made to overcome the difficulties above set forth b v so constructing the regulating mechanism that it would operate to very slowly separate the feeding carbon from the non-feeding carbon and thus insure the establishment of a persisting arc between them; but lamps so constructed proved inefficient and defective in their operation fortwo reasons. First, the application of means to the regulating mechanism for retarding the initial separating movement of the feeding carbon operated to deprive the regulating mechanism of that delicate and sensitive action which is essential to the proper regulating and feed of the carbon and to the maintenance of a persisting are, and, second, by imposing upon the regulating mechanism the duty of separating the carbons and establishing and drawing a long are, it rendered it impossible to maintain such a relation between the core and solenoid or armature and helix of the regulating mechanism as would insure its prompt and sensitive action in regulating and feeding the carbon.

The object of my invention is to provide an arc-lamp of such construction that the function of slowly separating the carbons and gradually drawing the arc to any desired length shall be performed by mechanism associated with and acting upon the lower or non-feeding carbon, while all the functions necessary to the regulation and feeding of the carbons shall be performed by mechanism associated with and acting upon the feeding carbon.

A further Objectis to provide means for preventing the rapid vibration of the carbons or of the regulating mechanism when the lamp is in operation. A further object is to provide an improved construction and arrangement of parts for supportingan arc-inclosing globe.

Vith these ends in View the invention consists in certain features of construction and combinations of parts, as will be hereinafter described, and pointed out in the claims.

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.ln the accompanying t'lrawings7 Figure il a view7 partly in vertical section and partly in side elevation, of an arc-lamp embodying my invention; and Figs, 2 and f3 are detailed views of the dash-pot.

A represents the lamp-floor, Y[from which is suspended the supperting-bracket 13, which is insulated l'rom the lloor and is strengthened and stitlened by means ot the short bracketarin e and ring b, said parts being either east in a single piece or made separate and l'astened together in any desired manner.

C is a solenoid supported in the lower end of bracket B. To the core D ol the solenoid is attached a carbei'i-holding socket c, which is insulated trom the core at d. A spiral spring E serves to uphold the core and the lower carbon li". Helix is composed of conductor ot" comparatively low resistance which is connected at one end to socket c by the flexible conductor g, while its opposite end is electrically connected atfwith bracket i3. To the under side of the solenoid is secured a dash-pet ll, which is illustrated in detail in Figs. 2 and il. Piston-rod g oi' the dash-petis connected to core D. Piston ll' is provided with an adjustable screw-valve ll?, by means of which the speed of the piston throughout its downward stroke may be retarded to any desired extent. in order to insure a prompt and quick upward movement oi' the core and lower carbon, piston ll is provided with any desired number of passages 7L', through which extend the stems 7L?, which are secu red at their lower ends to an annular ring-valve H3, which seats over and closes the passages 7l. Each one ot the stems hf is encircled by a spiral spring h3, which is seated at one end on the top ot' the piston. and at its opposite end against a collar or head on the upper end of the stem. ly this construction ol dash-pot the movement of the lower carbon may be retarded and made very slow and gradual throughout the entire downward movement, while its upward movement will be quick and prompt.

l is a shunt-solenoid, its helix 'i being coinposed ot' line wire of comparatively high resistance and electrically connected at its epposite ends with opposite binding-posts J J' ot' the lamp. This solenoid is supported above the floor b v brackets l" or in any othei' desired manner.

I' is a hollow core having a diamagnetic tube l2, secured te its lower end. A spider l:E is attached to the lower end el tube l2, and toits outer rim are adjustably secured the lower ends ol spiral springs l", which are secured at. their upper ends to the lower head et' the solenoid. The drawings illustrate only two springs7 while tour or more may be employed and arranged at equal distances apart around the tube il. A tubular carbon rod or holder K, passes down through the hollow core and tube and through the floor ot the lamp, it being encircled by an annular ring valve K', which 'is seated. upon the lamp-floor and snugly lits the carbon-rod. and serves to prevent the passage oi gases into the casing containing the regulating mechanism.

L a ring-clamp surrounc'liug` the carbonholder and resting upon the ring-valve l\"'. This clamp is provided with a groove 7u, into which projects the linger 7i" ol' the lilter A stop lo liinil'sthe upward movement ol' the ring-clamp.

lllithin the hollow carbon rod or holder is a piston l, which is suspended by a red attaehed at its upper end to the top ot' the casing, whereby the carlmn-red and piston serve as a daslrpot to steady the action ot' the npper carbon. To the carbon-rod is altzuhcd. by a ball-and-socket joint ZVJ a cover ill, which is constructed with a socket p1, in which the feeding carbon F secured by a set-screw in. Aresinelosing globe N connected to cover .M by means el setscrews n, which hear against the beveled surface/n on the globe and thereby Ytorce its ends into snug engagement with the cover. instead of employing the l'aslcn ing devices shown any suitable means may be used lor securingl the globe to the cover, so as to torni practically an air-tight joint be4 tween them. The cover is provided with a satetywalve n@ to n'cvent an excess ot' pres* sure within theglobe. The bottom ol the areinclosing globe is provided with a cover()1 having an opening o formed therein, through which the lower carbon li" passes and. within which it snugly lits.

Outer globe l" is ln'ovided at its upper end with an outwardly-flaring llange jp, which seats against the inclined face ot a bearing p, `termed en the under side ot the lloor olI the lamp or connected thercwil h. l`he globe is secured in placebymeans ol the set. .s rows pi and is rendered tight by the metall stripp" litting snugly against the bearing Vp. Het screws p2 by their engagement with the inv clined surface en the `l'lange p operate to l'oree the latter into snug Contact with the `inclined seat p. Casing (u) may be made el a single casting or may he nri vided with suitable doers or covered openings and is secured to the lam p-lloor by screws q.

The operation ot the lamp is as lollows: Yllhen no current is passing through the lamp, its cai-bons are very slightly separated, the upper carbon, together with the are-inclosing globe, being uphold by the springs ll, which serve to lit't the hollow core and litter and cause t-he ring-clamp to grip the carbon-rod and support it in its raised position. lllhen current is passed through the lamp, it first ilows through the helix ol the shuntssolenoid and energizes the latter sul'liciently te cause it to pull down thc hollow cere and upper carbon and to bring the two carbons into con tact. immediately the carbons are brought into contact practically the entire current will l'low from. binding-post J' through the lamp-licor A, carbon-holder l, carhonsl solenoid. C, bracket ,I3 te the binding-post- J', '.llie passage ol the and from thence to line.

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current through the lamp will operate to weaken the shunt-magnet and permit the springs 71;4 to lift the upper carbon and thereby establish an arc between the two carbons; but this are will be very short, owing to the fact that the stop k3 will so limit the upward movement of the upper carbon that it will be separated but a very slight distance from the lower carbon. At the same time the passa-ge of the current through the carbons, when brought into contact,will energize solenoid C and cause it to pull down its core and lower carbon supported by it; but the downward movement of the lower carbon is so retarded by the dash-pot II as tocause it to separate very slowly and gradually from the upper carbon, and hence it continues to descend until it has drawn an are of any desired length. The very slight initial separation ofthe carbons, due to the upward movement of the feeding carbon, operates to insure such a resistance to the passage of the current as will result in the rapid heating of the ends of the carbons without interrupting the circuit and extinguishing the arc, and the slow and gradual descent of the lower carbon will insure the drawing of an are of any desired length without extinguishing it.

Instead of operating in the manner above described the parts may be so adjusted that the carbons will be in contact when no currentis passin through the lamp. Now on the passage of current through the lamp the lower carbon will be drawn down very slowly,with the result that an exceedingly minute arc will be iirst established between them, which arc will sufiice to heat their adjacent ends and insure the maintenance of the arc,which will gradually be elongated until it has been slowly drawn to any desired length. An arc of normal length having been thus established between the two car-bons, it will continue to burn, and as it grows longer its resistance will increase,with the result that an increased amount of current will flow through the shuntsolenoid, and so strengthen it until it will pull down its core and cause the upper carbon to feed through the ring-clamp, and thus maintain a normal length of are.

Owingto the fact that the pull of the shuntmagnet varies with and is at all times dependent upon the resistance of the are, the regulating mechanism is so constructed and adj Listed that not until an arc of normal or predetermined length has been established by the downward movement of the lower carbon will such an equilibrium of forces be established between the shunt-magnet and the opposing springs as will insure that delicate and sensitive automatic adjustment and feed of the upper carbon which is necessary to the maintenance of a persisting arc of uniform length and brilliancy.

In order to prevent the rapid vibration of the upper carbon and the fluctuation of the arc and light produced by it, a dash-pot formed of a piston working in the hollow carbon-rod is employed to slightly retard and check the upward-and-downward movement of the feeding carbon, and still permit of a sufficiently prompt and sensitive action of the regulating mechanism to insure a steady and uniform light.

As an additional means for steadying the arc and for preventing any vibrations of the feeding carbon and regulating mechanism, the shunt-magnet is provided with a closed diamagnetic conductor I, which preferably consists of a closed tube of copper which may be located either inside oroutside of the linewire helix. On the passage of an alternating current througha solenoid the rapid rise and fall of the current will induce eXtra currents in the coils of the helix, which, acting on the core, will cause it to vibrate and impart very slight and rapid iiuctuations tothe arc. To obviate this trouble, a closed diamagnetic conductor I is placed either inside or outside of the helix and serves to suppress such eXtra current and thus shield and protect the core against theinlfluences of such rapid magnetic impulses, and enable a steady and reliable arc to be maintained.

In the event the arc should be extinguished from any cause the lower solenoid will be dc-nergized, with the result that the lower carbon will be instantly raised by the spiral spring D and brought into contact with the upper carbon, the dash-pot being constructed to permit of the quick upward movement of its piston, thus instantly re-stablishing the arc between them.

By mounting the are-inclosin g globe in the manner shown the escape of gases from the globe and the ingress of outerairthereto may be prevented by means of a cover which will permit of greater freedom of action to the carbon passing through it than is possible when the carbon is fed through the top of the globe for the following reason.

It has been practically demonstrated that the speeic gravity of the gases generated within an arc-inclosing globe is slightly less than that of the outer air, and hence the tendency of such gases is to rise and escape through the opening formed between the carbon and the walls of the hole in the cover through which the carbon is fed. Hence in lamps as heretofore constructed it has been found-necessary to form a tightjoint around the upper and feeding carbon to prevent the escape of gases and ingress of outer air,and the means resorted to forproducing such tight joint have been found to more or less interfere with the adjustment and feed of the carbon. By inverting the globe and providing its upper end with a tight imperforate cover, which will prevent the rise and escape of gases from the globe and also the fall of the outer air into its upper end, the gases generated therein will be confined within the globe and form a seal around the are, which will be preserved by a cover applied to the lower end of the globe and having a hole TOO IOS

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l'orined therein ol' such size that the lower carbon may freely slide therein.

By connecting both the upper carbon and the arc-inelosing globe to the carbon rod or holder by a ball-and-socket joint and causing` the lower carbon to serve as a guide for the lower end of the globe and upper carbon the two carbons are retained in alinement and ample lateral movement in all directions is afforded the globe to provide for any irregularities that may exist on the surface of the lower carbon.

To trim the lamp, the set-screws p2 are loosened and the outer globe P is lowered and suspended from bracket B by means of the sliding` connection S, connected at one end with the metal strip 2f; and engaging the bracket at its forward. end.

IVhile the lamp iis especiallyv adapted for use with an alternating` current on constantpotential circuits, it is evident that it may be used with a straight current and also maybe used on'constant-eurrent circuits.

IIaring fully described my invention, what I claim as new, and desire to secure by Letters Iatent, is-

ll. In an are-lamp, the combination with its earbons and means `for retaining them slightly separated when no cu rreut is passingv through the lamp, of means .for automatically bringing` the earbons into Contact and means for separating; them very slightly when current is sent through the lamp and means for slowly and gradually separating'thenon-fecding car bon from the feeding; carbon and thereby slowly drawing; the arc to any desired length, substantially as set forth.

2. In an arc-lamp, the combination with the lower and non'leeding carbon, oi' means for slowly and gradually separating' it from the upper and 'feeding carbon and thereby drawinf;` an arc ot' any desired length, of means for permitting of the quick upward movement of the lowercarbon when the are is extinguished, substantially as set forth.

El. In an arelamp, the combination with its cai-bons, of an arcinelosinib l globe constructed and arranged to be Ied downward with the` upper carbon, and provided with a cover at its lower end within which the lower carbon snugly lits, substantially as set t'orth.

l. In an are-lamp the combination with the carbon-holder and the upper and. lower earbons, of an arc-inelosing globe connected with and suspended from the carbon-holder, said globe being provided at its lower end with a cover in which the lower carbon snugly fits, substantially as set forth.

5. In an are-lampthe combination with the carbon-holder, and lower and non-feeding carbon, oi' an arc-inclosingl globe and feeding carbon, suspended from the carbondlolder by a universal joint, said globe being provided with a cover on its lowerend having au open ing in it through which the lower carbon passes, substantially as set i'orth.

(i. In an arcslamp the continuation wilh the carbon-holder, lamp-floor and annular valve encircling the carbon-holder and seati ng upon the lamp-'iloor, oi' a ring-clamp located over and adapted to rest upon said annular vulve, substi'intially as set `forth.

7. In an arcdamp the combination with its cai-bons of an are-inelosingl globe suspended from `its upper end, whereby its lower end is adapted to move laterally in any f lreetion, the lower end o'l the globebeinfl provided with a cover having' an opening through whit-h the lower carbon passes, substantially as set lorth.

In testimony whereof I have signed this specification in the presence ol. two subst-rib ing` witnesses.

.HENRY A. SIC'YIUlIh.

Witnesses G. Nor'jrxeiftiin, G. F. DowNrNo.

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