US781937A - Electric-arc lamp. - Google Patents

Description

No. 781,937. PATENTED FEB. 7, 1905. A. G. DAVIS & J. B. HUBBELL.

ELECTRIC ARC LAMP.

APPLICATION rum) JULY 7, 1904 bell,

. Inventors: JIlbert G. Davis,

John E. I-I?b y l 4 8 P 6 N J 1v 9!. l J 34 O M 8 !||.-|rr E 3 x 4 .Q P.

n ll Witnesses.

UNITED STATES Patented February '7, 1905.

PATENT OEEIcE.

ALBERT Gr. DAVIS AND JOHN E. HUBBELL, OF SGHENEG'UADY, NEIV YORK, ASSIGNORS TO GENERAL ELECTRIC COMPANY, A CORPO- RATION OF NEW YORK.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 781,937, dated February '7, 1905.

Application filed July 7,1904. Serial No. 215,569.

T0 rtZl whom, it may concern.-

Be it known that we, ALBERT Gr. DAVIS and JOHN E. HUEBELL, citizens of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Arc-Lamps, of which the following is a specification.

hen electrodes for arc-lamps are constructed out of many materials which may be advantageously employed for the purpose, there is a tendency to the formation on one or both of the electrodes of the lamp of a film, layer, or coating of material which is a nonconductor or poor conductor of electricity, at least when cold.

Our present invention has for its purpose the provision of suitable means for preventing this layer or film of material from injuriously affecting the operation of the. lamp in which the electrodes are employed.

In carrying out our invention we have provided means for puncturing the non-conducting film or layer and penetrating through to the good conducting material forming the body of the electrode.

It has been heretofore discovered that with suitable negative electrodes giving a flaming or luminous are positive metallic non-consuming electrodes may advantageously be employed. In the present application we have shown our invention embodied in an arc-lamp employing a non-consuming positive electrode, though our invention in all of its aspects is not limited to use with such an electrode or, indeed, to use with any particular form of lamp mechanism.

The various features of novelty which characterize our invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding, however, of our invention reference maybe had to the accompanying drawings and description, in which we have illustrated and described embodiments of our invention.

Of the drawings, Figure 1 is a view, partly in elevation and partly in diagram, showing one embodiment of our invention. Fig. 2 is a similar view, with parts in section, showing a different form of our invention. Fig. 3 is a view, partly in section with parts broken away, taken at right angles to Fig. 1, showing a portion only of the mechanism shown in Fig. 1; and Fig. A shows another form of puncturing device.

Referring to the construction shown in Figs. 1 and 3, the mechanism there shown is substantially like that shown in an application for Letters Patent on improvements in arclamps, Serial No. 181,332, filed jointly by Richard Fleming and Cromwell A. B. Halvorson, Jr., November 16, 1903, except as the same has been modified by the addition of our present invention. In this construction 1 represents-a platform, from the under side of which extends a tubular member 2, formed, preferably, of some metal, such as copper, which is a good conductor both of heat and electricity. A pair of bowed members 3have clamped between their ends the ends of the positive electrode of the lamp, which is in the form'of an arc-shaped bar 4, made of some material, such as wrought-copper, which is a good conductor both of heat and electricity. The bowed members 3 are pivoted to the member 2 to turn about an axis extending transversely to the axis of the member 2. Slots are formed in the wall of the mcmberQ, through which the bar 4. passes. A puncturing device or member 5 is carried by the bar at at one side of its center. The member 5 may be formed of some material like musketsteel, which when heated is tempered by cool ing slowly in air, orof other suitable material. The member 5 may be removably secured to the bar A by dovctailing, as shown. Preferably a driving lit between the tenon of the member 5 and the walls of the slot in the bar 4 is employed. A sharpened projection 5 extends from the member 5. \V hen the bar :h is in the position shown in Fig. 3, the projection 5 is in line with the axis of the member 2. A projection 6 from one of the bowed members 3 is pivotally connected by links 7 to a U-shaped armature 8, located above the platform 1. To the under side of the U-shaped armature 8 is secured one member 9 ofa dashpot. The other member 10 of the dash-pot is carried by the platform 1. The dash-pot employed is arranged to prevent a rapid downward movement of the armature 8 without retarding its upward movement. The apcrtured end of the pawl member 11 of a clutch 12 is loosely sleeved to the stem 9, connecting the armature 8 and dash-pot member 9. The yoke of the clutch 12 surrounds a tubular member 13, which slides upon a post 14. The post 14 is secured at its upper end to a cross-head 15, supported by a post 16, which is carried by the platform 1 and extends par. allel to the post 14. The lower end of the tubular member 13 carries an arm 17, which in turn holds the negative consuming electrode 18 of the lamp in line with the axis of the tubular member 2. A guide carried by the member 13 engages the post 16 to prevent angular displacement of the member 13. The yoke member of a clutch 19 surrounds the member 13 below the clutch 12. The pawl 20 of the clutch 19 is formed with an enlarged opening in it, through which the post 16 passes, the post serving as a guide to prevent angular movement of the clutch 19. The movement of the pawl 20 is limited by stops 21 and 22, carried by the post 16 above and below the pawl 20, respectively. A projection from the stop 21 forms a rest for the yoke member of the clutch 12 when the mechanism is in the position shown in Fig. 1. A helical spring 23, one end of which is secured to a bracket and the other end to the free end of the pawl 20, forms a means for normally holding the pawl in the position in which it locks the clutch 19 to the member 13.

Current is supplied to the lamp at the terminals and 31. The terminal 31, which is the negative terminal of the lamp, is connected to the electrode 18 by conductor 32. A conductor 33 leads from the terminal 30 to one terminal of the winding of a cut-out 34.

, The other terminal of the winding of the cutout 34 is connected, through a screw 35 and conductor 36 and members 3, to the are-shaped bar 4, which forms the positive electrode of the lamp. \Vith the lamp as actually constructed connection is ordinarily made directly to the walls of the member 2 and the bowed members 3 are connected to the member 2 by a flexible conductor 37, as shown in Fig. 3. The cut-out member 34 is provided with a pivoted armature 38, carrying a contact 39. \/V hen the winding of the cut-out 34 is not operatively energized, the contact 39 is in engagement with the contact 40. hen, however, the winding of the cut-out 34 is operatively energized, the armature 38 is tilted and the conductors 39 and 40 are separated.

A conductor 41 connects the terminal 30 to regulating"resistance 42. The contact 39 is connected by conductor 43 with one terminal of the winding 44, which cooperates with the U-shaped armature 8. The other terminal of the winding 44 is connected to the terminal 31. One terminal of the potential coil 45 is connected to the conductor 41 by a conductor The other terminal of the potential coil 45 is connected to the conductor 43 by a conductor 47. The core of the potential coil 45 carries an insulated contact member 48. The movable armature of the potential coil carries an insulated contact 49. The contact member 49 is connected with the conductor 33 by a conductor 50. A conductor 51 connects the contact member 48 to the lower terminal of the cut-out member 34.

The out-of-service condition of the lamp mechanism is shown in Fig. 1. On connecting the terminals 30 and 31 to a suitable source current will begin to flow from the terminal 31 and terminal 30 through a circuit including the winding 44, conductor 43, contacts 39 and 40, and conductor 41. This will cause the armature 8 to be raised. As the armature 8 moves upward the clutch 12 will engage the member 13 and the electrode 18 will be moved toward the bar 4. At the same time the bar 4 will be moved by the links 7 from the position shown in Fig. 1 to the position shown in Fig. 3, where the point 5 of the puncturing device is substantially in line of the axis of the member 2. As the puncturing device moves in line with the axis of the member 2 the upper end of the electrode 18 is moved somewhat violently into contact with the tip of the puncturing device. hen the electrode 18 is formed out of titanium carbid, for instance, the body of the electrode is a fairly-good conductor of electricity, regardless of its temperature. After such an electrode has been used for some time in an arc-lamp, however, the tip of the electrode becomes covered with a layer or coating composed largely of titanium oxid. This film or coating isa poor conductor of electricity when cold. At the same time a deposit composed largely of titanium oxid is usually formed upon the portion of the upper electrode of the lamp adjacent the are. This deposit is also a poor conductor of electricity, particularly when cold. \Vith many other materials from which an electrode giving an efficient luminous arc may be formed the same or similar tendencies to the formation of a film oreoating of non-conducting material on the electrode-tip or on adjacent objects, or both, is experienced. With the use of the puncturing device 5, provided with a sharpened edge or point 5 however, good contact will always be established between the body of the electrode 18 and the electrode 4, as the engagement between the electrode 18 and the point 0 is such as to force the metal of the contact-- the contact 40. This conductor includes a 1 point 5 into intimate engagement with the I3 body of the electrode 18, regardless of any film or coating of poorly-conducting material which may have been produced on either electrode 18 or the puncturing-point 5. The downward movement of the electrode 18 is limited by the engagement of the pawl 20 and the stop 22. After the arc is established in the manner hereinbefore described it is ordi narily maintained until from the increase in arc length, caused by the consumption of the electrode 18 or other cause, the potential voltage of the arc is increased beyond a predetermined amount. When this occurs, the winding of the potential coil 15 is energized sulficiently to move the contact 19 into engagement with the contact 48. This throws a lowresistance shun t, comprising the conductor 50, contact 49, contact 48, and conductor 51, about the winding of the cut-out 3 1. Under these conditions the contact 39 drops into engagement with the contact 40 and the feeding operation of the lamp is repeated. The clutch 19 moves upward with the tubular member 13, by reason of the action of the spring 23, until the pawl 20 engages the under side of the stop 21, after which further upward movement of the member 13 takes place without corresponding movement of the clutch 19. In each feeding operation of the lamp the member 13 is pulled through the yoke of the clutch 19 a distance equal to the amount consumed since the previous feeding operation. hen the windings 1 1 are deenergized, the member 13 and electrode 18 move downward a distance equal to the amount of play of the pawl 20 between the'stops 21 and 22. It will thus be seen that in the ordinary operation of the lamp the arc struck after each feeding operation is of constant length.

Instead of the form of puncturing device shown in Figs. 1 and 2 we may use the form shown in Fig. 4. In this form of our invention the puncturing portion 5 is in the form of an elongated edge, as shown, rather than in the form of a conical point. This form of puncturing device facilitates the transfer of the upper end of the are from its startingplaee on the puncturing device 5' to the body of the bar 1 and lessens the time during which the arc extends from the device 5, thus lengthening the life of the puncturingdevice.

In the form of our invention shown in Fig. 2 the negative electrodes 60 may be similar to the electrode 18, heretofore described; but it is not moved in the feeding operation of the lamp. The positive electrode of the lamp, however, is different. It comprises a somewhat massive tubular shell member 61, formed of some material, such as wrought-copper, which is a good conductor both of heat and electricity. A metallic bar 62 is slidingly mounted in the bore of the member 61. The lower end of the bar 62 carries a detachable puncturing member 63, having a sharpened point which is preferably formed of the same suitable material as the member 5. The upper end of the bar 62 is provided with a shoulder 6 1. A washer surrounds the bar 62 above the upper end of the member 61 and below the shoulder 64:. The washer 65 is connected to the armature 66 of a solenoid 67, which is carried by the member 61 through a bracket 68. A spring-pressed pawl 69 hooks over the upper end of the bar 62 and locks it to the member 61 when the lamp mechanism is in the condition shown in Fig. 2. When the coil 67 is energized, however, the washer 65 moves upward and engages a cam-surface 70 of the pawl 69 to force it out of engagement with the bar 62. The upward movement of the washer 65 is continued until the puncturing device 63 is moved from the exposed position shown in full lines in Fig. 2 to position shown in dotted lines in Fig. 2. The member 61 passes through the opening in a washer-clutch 75. One end of the washerclutch is connected to a U-shaped armature 76 by a connecting-rod 7 7. A number of ratchet-teeth 78 are shown as formed on the bar 77. The pivoted armature 79, cooperating with an electromagnet 80, is used to engage the teeth 78 and prevent downward movement of the connecting-rod 77 when the. electromagnet 80 is deenergized. \Vhen the electromagnet 80 is operatively energized, however, the armature 79 is moved away from the position in which it engages the teeth 78. Conductors 81 and 82 supply current to the lamp. A conductor 83 connects conductor 81 to the lower negative electrode 60 of the lamp. The conductor 83 may contain a suitable regulating resistance 84. One terminal of the winding 85, which cooperates with the U-shaped armature 7 6, is connected to the conductor 82. The other terminal of the winding 85 is connected to one terminal of the coil 67. The other terminal of the coil 67 is connected to the tubular member 61 by a conductor 86. The member 61 and bar 62 are in good electrical contact through their physical engagement with each other. One terminal of the electromagnet 80 is connected to the line 86 by conductor 87. The other terminal of the electromagnet 80 is connected to the electrode 60 by conductor 88. The out of-service condition of this form of our invention is that shown in Fig. 2. When the conductors 81 and 82 are connected to a suitable source, current will begin to flow through a circuit in cluding conductor 83, conductor 88, winding of the electromagnet 80, conductor 87, coil67, and winding 85. This current will be suflicient to operatively energize the coil 80, whereupon the armature 79 will be attracted and will release the bar 77. This will allow the member 61 and parts secured to it to move toward the electrode 60. The weight of the parts are such that the tip of the puncturing device 63 will engage the upper end of the electrode 60 with some violence. This will be sufficient to puncture any film or layer of non-conducting material which may cover the end of the electrode or the puncturing device and insure good electrical contact between the bar 61 and electrode60. As soon as contact is established between the electrodes 60 and bar 62 current will begin to flow through a circuit comprising conductor 83,.

electrode 60, bar 62, member 61, conductor 86, coil 67, and winding 85. Passage of this current will be suflicient to opcratively energize the coil 67 and winding 85. The coil 67 and parts moved thereby are constructed to operate more rapidly than the winding 85 and parts composed by it, in consequence of which the bar 62 is first drawn up in the member 61, after which the member 61 is moved upward by the action of the winding 85 of the armature 76. As the bar 62 is moved out of con- 'tlietavith the electrode 60 an arc will be drawn between them which will be immediately transferred from the device 63 to the end of the member 61. To avoid any trouble from the cementing together of the bar 69. and member 61 by material deposited on their lower ends from the are, the bore of the member 61 may be enlarged at the lower end, as shown.

It will be obvious to all those skilled in the art that many changes may be made in the forms in which our invention is shown as embodied without departing from the spirit of our invention, and it is not intended that the claims hereinafter made shall be limited by the construction shown more than is made necessary by the state of the art.

W'hat we claim as new, and desire to secure by Letters Patent of the United States, is

1. In an arclamp,an electrode, a second electrode, a film-puncturing device carried thereby,and means for causing said film-puncturing device to engage the first-mentioned electrode in the feeding operation of the lamp.

2. In an arc-lamp, a non -consuming electrode,a consuming electrode,afilm-puncturing device carried by the non-consuming electrode, means for causing said puncturing device to engage the consuming electrode in the feeding operation of the lamp.and means for moving said film-puncturing device out of the arc path after an arc is started between the electrode.

3. In combination, an electrode the arcing end of which becomes covered with a non-conducting film or layer in the operation of the lamp, and means for puncturing the layer and starting an are from said electrode.

1. In an arc-lamp, a consuming electrode,a non-consuming electrode,a puncturing device carried thereby,and means for causing a somew hat-violent engagement between the consuming electrode and the puncturing device.

5. In combination, a pair of cooperating electrodes,and means for puncturing a film or coating of poorly-conducting material which may have been formed on one or both of said electrodes to facilitate the passage of an are between said electrodes.

6. In an arc-lamp,a pair of co '3perating electrodes,and means for puncturing a iilm or coating of poorly-eonducting material, which may have been formed on one or both of said electrodes, to facilitate the passage of an are between said electrodes, said means comprising a sharp device carried by one of said electrodes, and mechanism for bringing about a somewhat-violent engagement between said device and the other of said electrodes.

In witness whereof we have hereunto set our hands this 6th day of July, 1904-.

ALBERT G. DAVIS. JOHN E. HUBBELL. \Vitnesses:

BENJAMIN B. HULL, HELEN On'rom').

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