US638703A - Electric-arc lamp. - Google Patents

Description

No. 638,703. Patented Dec. I2, |899. W. J. COCHRAN.

ELECTRIC ARC LAMP.

(Application led Jan. 23, 1899.)

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NITED STATES PATENT OFFICE.

'WALTER J. COCHRAN, OF LE ROY, NEV YORK, ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, TO DAVID J. BISSELL, OF SAME PLACE.

ELECTRIC-ARC LAM P.

srncrrrenrrolv forming part of Laers Patent No. 638,703, dated December 12, 1899'.

Application filed January 23, 1899. Serial No. 703,191. (No model.)

Be it known that I, VALTER J. COCHRAN, a citizen of the United States, residing in the village of Le Roy, county of Genesee, and State of New York, have invented a new and useful Electric-Arc Lamp, which may be used with any kind of current, of which the following is a specification.

My invention relates to improvements in electricearc lamps, and more particularly to improvements in an arc-lamp designed to prevent the casting of a shadow.

The objects of my invention are to provide for such a lamp means of a simple and effective construction to automatically produce and maintain an arc of the desired length and in the desired position with the least possible friction of the operating parts, with the use of a small number of parts to be controlled by the current and by the employment of a current of less strength than is usually necessary for a lamp of this character, to provide for maintaining the arc at all times in a fixed position when the lamp is burning, to make a lamp compact in all its parts, and to secure a greater convenience in the operation of cleaning and trimming.

In the accompanying drawings, Figure l is a vertical section, partly in elevation, of a lamp with my improvements attached thereto; Fig. 2, a rear view in elevation of part of lamp, showing coil-s upporting brackets; Fig. 3, a detail top plan of one of the clutches; Fig. 4, a detail plan of cover-plate, and Fig. 5 a section of one of arms supporting the cover on line o: a: of Fig. 4.

My invention is herein illustrated and described as applied to and adapted for use with an alternating inclosed arc-lamp.

Referring to the drawings, a is the handle of the lamp, by means of which it is supported. The handle is swiveled at its lower ends to stud-bolts l), which pass through a plate c and are rounded at their lo wer ends to receive nuts d. Rubber washers e are clamped between a shoulder of the bolt and the plate and between the nut cl and the plate, respectively, by metal washers f, and the handle thus effectively insulated from the plate and its connected parts.

Secured to or preferably integral with the plate c are the radial arms g g and t 7L, adaptied to support the cover t'. Arms g are provided at their outer ends with spring-catches consisting of stiff outwardly-bent vertical springs j, each having a tooth or ledge 7a, on which a flange or bead of the cover at the upper end thereof is adapted to be supported. lVhen the parts are in position, the ledge 7s engages with the llange 19 on the cover. On 6o the ends of arms 7L and under side thereof are cut-away portions Z, which lit over the rixn ofthe cover and by their shoulders hold the same steady. The covert' isV made of lead,

so as to deaden the vibrations thereof, and thus prevent the vibration of the lamp itself. Integral with the plate c are the lugs m at front and rear of the lamp having arms n. Between the rear arm and corresponding standard o of a bracket p is clamped by screw 7o connections the iron core q of a choke-coil r. The core is also screwed to the arm of the front lug. The core is a horseshoe-core and is separated at the point of support between the bracket and the rear plate-lug. The bracket p is provided with legs s, to which is secured by countersunkscrews a circular plate or disk t, made of porcelain or othersuitable insulating material. Formed on the bracket are the split sleevese,havingclamping-screws, 8o by which the screws are clamped to and support the metal tubes tu, which are insulated from said sleeves by mica or other suitable insulating material. The tubes ru extend from under the plates c and their lower ends converge. These tubes are adapted to contain the carbons and their holders. The carbonsxare placed in the tubes and are adapted to be fed down therein by gravity. Over the upper end of cach carbon is fitted a metal 9o slotted sleeve y, between which and a metal plug e', driven in the sleeve, are clamped spring-brushes l, which are bent or curved near their upper ends, and thereby make clectrical contact with the tubes. The tubes cX- tend onlya short distance below the bracket p, and from the tubes the carbons extend to and through the plate t, converging a short distance below the plate and forming the are. The carbons may converge at any suitable roo angle, that shown in the drawings being about sixty-'live degrees.

The under surface of plate t is made concave at the center in order to form a reflecting-surface 2 for the arc, the plate being made of or faced with suitable material for this purpose. The concavity 2 forms a corresponding convexity in the upper surface of the plate.

A small glass globe 3, hinged to the bottom of plate t and provided with a headed screw to fasten it to the plate, is adapted to inclose the arc. A larger hinged globe l, provided with aspring-catch and secured to the plate, incloses the smaller globe. In practice the inner globe may be dispensed with, as it will be found that the outer globe can make the arc-space suiiiciently air-tight.

Mounted on bracket p is a workin g magnet 5. Vithin the magnet is a sliding armature or core G. A pistou-rod 7 is secured to said armature and at its upper end is provided with a piston-head S, adapted to work in a dash-pot 9. The dash-pot is pivoted to a small yoke 10, which in turn .is pivoted by right-angle arms to another yoke 11, that is riveted or screwed to the plate c. To the lower end of the piston-rod is secured a horizon tal arm 12, ol fiber or other suitable insulating material, and to each end of this arm is pivoted a link 13. The lower end of each link is pivotally connected to the jaw 14E, embracing the carbon, and this jaw is also pivoted to a jaw 15, said jaws together forming a clutch adapted to engage the carbon. When the clutches are at rest and the carbon-points down together and out of operation, the jaws 14 will rest evenly on the ledge 1G of the conveX portion of the plate t.

The circuit is made through binding-post 17, working magnet 5, through one of the Wirings of choke-coil 7', then through the carbons and tubes to binding-post 18.

The connection is made to any one of the several coils of the choke-coil in accordance with the pressure required to accord with the voltage of the current in producing an arc of the desired length.

The operation of the invention is as follows: The carbons and other parts of the lamp are shown in working position. The clutches being drawn up by the armature, the inner jaws of clutches will engage and support the carbons. The normal length of the arc is determined by the strength of the current and the strength of the current is determined by the resistance of the choke-coil. The relative location of the working magnet, armature, and clutches is such that when the current is of normal strength the carbons will be held in the proper position to maintain'the normal length of the arc. When the ends of the carbons in burning are consumed and separated, the resistance of the lengthened arc will break or diminish the current, lessening the attraction between the working magnet and the armature and causing the latter, with the arm 12, to descend and the clutches to strike the plate t, whereupon the grip of the inner jaws 14E of the clutches upon the carbons will be relaxed and the carbons will feed down and approach each other. Instantly the full strength of the current will be established and the armature will be attracted upwardly to its normal position, picking up the carbons by means of the pivoted clutches, and thus striking the proper arc. The piston attached to the armature and moving in the dash-pot 8 will check the movement of the armature and prevent itfrom being retracted too far by the renewed attraction of the magnet. It will be seen that the pick-up device set forth will lift the carbons in the direction of their axes. This mode of separating the carbons to strike the arc will afford the least possible resistance to the working of the current. Since the clutches are attached directly to the carbons, which, together with the armature, slide freely in their bearings, there will be very little weight an d practically no friction to oppose the movement of the ad justed parts, and hence but a slight current is required for such movement. The action of the clutches is almost instantaneous, and all sputtering is thus obviated.

When the lamp is not in use and the circuit not made, the ends of the carbons will rest against each other, and the jaws 11i of the clutches will rest on the ledge 1G.

The ashes from the carbons will fall into the globe 3 and can be readily removed therefrom when the globe is unhooked. The burned carbons can be readily removed and replaced by new ones, no set-screws or clamps being required for their support and adjustment, the slotted holder g/ having the action of a spring-holder for centering the carbon and electrically connecting carbon and tube.

The insulating carbon-guiding plate tenables the insulation usually employed between the parts in electrical circuit and the supporting-frame to be dispensed with, while the construction and location of the plate enable the reflecting-surface to be readily formed thereon.

By making the cover of lead the vibrations of the cover and lamp are neutralized.

rlhe cover may be easily removed from the spring-catches and may be supported when removed by chains or other suitable means.

It is obvious that numerous changes in the details of construction may be made without departing from the principle of my invention.

lVhat I claim is* 1. In an arc-lamp, diagonally-converging tubes liked to the frame of the lamp, gravityfed carbons sliding in said tubes, in combination with an arc-maintaining and pick-up device comprising an armature, pivoted clutches directly engaging said carbons, and gripping the carbons on the attracted movement of the armature, and laterally-yielding connections between said armature and clutches, whereby the carbons are picked up in the direction of their axes and at the same time separated, substantially as described.

IOO

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2. In an arc-lamp, diagonally-converging carbons, a magnet and armature or core sliding in said magnet, and limited in its attracted movement solely by the resistance of the arc and strength of the current, in combination with pick-up clutches, said clutches provided with means to grip and lift said carbons, and laterally-yielding connections between said armature and clutches, whereby the carbons Will be lifted in the directions of their axes and at the same time separated, substantially as described.

3. In an arc-lamp, diagonally-converging carbons, fixed holding-tubes for said carbons, a pair ot' pivotally-connected jaws embracing each of said carbons, a link pivoted to one of said jaws of each pair, a bar to which the opposite ends of said links are pivoted in combination with electrical means forautomatically controlling the opening and closing ot said jaws, and means With which said jaws are adapted to contact to relax the same, substantially as described.

4. In an arcelamp, in combination with gravity-fed diagonally-converging carbons, Xed holding-tubes for said carbons, a verticallymoving armature and means to attract the same, a piston attached to said armature, a dash-pot in which said piston moves, clutches consisting of pivoted jaws, means to pivotally connect said arma-ture and a jaw of each clutch, said clutches adapted to grip the carbons for holding them in arcing position and to. release them. to permit their feed, said carbons adjustable in the directions ot' their axes and means to govern the release of the clutches, substantially as described.

5. The combination With the converging carbons of a clutching device consisting of a top cross-bar, between the carbons and above the convergence of the same, a link hung to each end of said bar, an nnerclutch-jaw pivoted to each of said links, an outer clutchjaw pivoted to the inner one, said inner and outer jaws embracing a carbon, an armature to which said top cross-bar is secured, said inner janT adapted to grip the carbon in the upward movement of the bar, substantially as described.

l/VALTER J. COCHRAN.

Witnesses:

FRANK W. RUBY, FREDK. G. AircnrsoN.

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