US1091641A - Arc-lamp. - Google Patents

Description

J. T. H. DEMPSTER.

ARC LAMP. v APPLIOATION FILED NOV.16, 1903. 1,091,641 Patented Mar. 3 1, 1914.

2 SHEETS-SHEET 1.

INVENTQF-i. John T HDempst'n q ah M 1:1

J. T. H. DBMPSTER. ARC LAMP.

APPLICATION FILED NOV. 16, 1903. 1 091 641 Patented Mar. 31, 1914.

2 SHEETS-SHEET 2.

MTNESSES: v lm/ DR 4 1%? bJoHnTHUempsfen {MAM/Y UNTTEDF STATESPATEN '1 ()FFICE, 30m: '1. 1'1- nnmre'rnn, orsciinmicmny, NEW YORK, nssrcmon TO GENERAL nmcrmc (mumm A conronnrion or NEW YORK.

Also-LAMP.

To all who-m may concern:

Be it known that I, JOHN T. H. DEMP- s'rnn a citizen of the United States, residing at chenectady. county of Schenectady, State of New York, have invented certain new and useful Improvements in Arc- Lamps, of which the following is a specification.

The object of my present invention is to improve the construction and operation of arc lamps.

More particularly my invention relates to are lamps in which the major portion of the illumination comes from the arc itself as distinguished from those lamps in which the major, portion of the illumination comes from electrodes heated to incandescence. In

I such lamps it has been found that one of the electrodes can advantageously be so constructed and arranged that it will not consume during the normal operation of the lamp, and my present invention contemplates a certain novel construction and arrangement of such a non-consuming elec trode.

My present invention also contemplates a novel electrode feed mechanism. This mechanism I have hereinafter illustrated and described as employed in a lamp provided with my novel form of non-consuming electrode, but it is not necessarily in all respects limited to such conjoint use.

These features of novelty, together with others which characterize my present invention, are pointed out wi 11 particularity in the claims annexed to and forming a part of this specification.

For the better understanding of my in: vention reference may be had to the annexed .drawings in which I have illustrated one embodiment of my invention.

Of the drawings, Figure 1 is a sectional elevation of an arc lamp; Fig. 2 is an-elevation showing part of the mechanism of the lamp; Fig. 3 is a similar View taken at right angles to Fig. 2; Fig. 4 shows a de tail of the feed mechanism; Fig. 5 shows the bottom of the lamp casing and the method of supporting the globe; Fig. dis a diagram illustrating the circuits of the lamp, and Fig. 7 is' a perspective View 'of the manually operated cross-head-for disengaging the clutch.

Referring to't-he drawings, 1 represents the lamp cap or top, on the upper side of Specification of Letters Patent. Application filed November 16, 1903i Serial No. 81,299;

which suitable supporting means are placed. Binding posts 3 and 3' of ordinary construction are also carried by the cap 1'. A tubular member 45 is securedto the under side of the cap 1' by screws 4:. At the lower end Patented Mar.31,1914f.

of the member 4 a disk-like platform 5 is carried. Posts 6 depending from platform 5 carry at their lower ends another disklike latform 7. Some distance beneath the plat mm 7 an annular member 8 is carried by means of the screws 9 which are threaded into the under side of the latform 7. A tubular member 8 extends ownward'from the inner periphery of the annular member 8 for a purpose to be hereinafter set forth.

A circular plate 10, of some material, such as copper, which is a good conductor of heat and electricity, is located in the space between the platform 7 and the annular member 8. This plate is separated-and insulated from the platform 7 and annulai; member 8 by means of the tubular spacing members 11 which surround the bolts or screws 9. From the under side of the member 10 a cylindrical rod or pencil 13 extends forming one of the electrodes of the lamp.

The rod or pencil 13 is made out of some material which is a good conductor both of heat and electricity, such as copper, and is secured to the Plate 10 in any suitable manner, as by means of a threaded extension of the rod or pencil which is screwed into a threaded opening formed for the purpose in the plate 10. The electrode 13 passes centrally through the annular member 8 projecting below the annular member about as far as does the tubular member 8. A jacket or layer let of mica, or similar material, surrounds the upper portion of the rod or pencil 13 extending down to within a short distance of the lower end of the pcncil. Another bushing or tube section 15 of substantially the same length as the rodor pencil, and preferably formed out of porcelain, surrounds the mica jacket and inclosed pencil. It will be observed that the lower end of the pencil 13 is separated from the insulating jacket by an annular' space 15.

The lower electrode 16 of the lamp, which may be formed of, or contain, magnetite or titanium carbid, or other materialgiving a flaming or luminous arc, is held in a socket, 17 carried by a cross head 18. The cross head 18 is secured to the lower end of a pawl. and carries v is limited by i pair of rods 19 which pass through apertures formed for the purpose'in platform 7, annular member 8 and plate 10. Suit able bushings 20 which may be formed out of porcelain or other insulating material serve to insulate the rods 19 from the plate 10. cross head 18 unites the upper ends of the rods 19. The cross head 18' is secured to the lower end of a rack bar 21. The upperend of this bar isgadapted .to enter the tubular member 4 with which it cooperates; to form a regulating dashpot. A shaft 22', journaled in bearings 23-. carried by the posts 6, carries a which meshes with the teeth on the rack 21. The shaft also carries a ratchet wheel 2-1 somewhat larger than the gear wheel 24:.

A pair of magnet coils 26 are supported by a post or member 27 formed of magnetic material to which their cores 28 are connected by screws 29. The post 27 has an oiiset portion 28 at its lower end. which rests against the upper surface of platform 7. Screws 29 passing through the offset portion of 28 secure it to the member 7. The armature 30 7; A spring 33, having one end secured to a lag formed for the purpose on the post 27 and the other end secured to a similar lug formed for the purpose on the armature 30 below its support 31, normally holds the armature in the position shown in Fig. 2. The outward movement of the armature 30 a stop 34 which may consist of a projectionor extension of one of the cores 28 which passes through a slot or channel formed for the purpose in the armature 30 and is formed with a bend at its outer end,

spring pawl 35, the outer end of which normally engages the ratchet wheel 25, is secured to the upper end of the armature 30. A. member 36 loosely pivoted to the armature 30 above the pawl 35 has near its free end a slot indicated in dotted lines in Fig. 2, and the tooth of the pawl passes through that slot;-it also has an oll'set portion 87 at its outer end. The'pawl 35 and member are so arranged .that when outer end 37 of the member 36 is depressed, it engages the it out of engagement with the teeth of the ratchet wheel 25. he teeth on ratchet wheel 25 and pawl 35 are so arranged that when themagnctcoils 26 are energized and the arnmture ill is attracted the wheel 25 will be minted in the direclion indicated --by the arrow in Fig. 2. /Vhcn the magnet coils 9,6 are dciinerg'izwl the armature 30 will return to the position shown in 2. A dog secured to the under side oi the platform :7 nm'mally prevents a. rotation of the ratchet wheel 25 in the direction opposite to that indicated by the arrow in Fig. 2.

spur gear wheel 24 A spring contact member 39, secured in any suitable manner to the under side of platform 5, is n'ormally in engagement with one'en'd of a contact screw 40 passing through a-member 41, also secured to the under side of platform An arm or member 42 projecting from the arn'iature 30 is adapted to engage the lower end of the member 39 and move it out of engagement with the end of the screw 40 for a purpose to be hereinafter set forth when the arl'nature 30 approaches the end of the core 28' under the action of the coils426.

A magnet coil 48 having its axis vertical is carried on the upper side of the platform 7. The armature 44 which coiiperates with this magnet coil is pivoted at one end to a post or member 45 carried on the upper side of platform 7. A helical spring 46, having one end secured to a. lug formed for the purpose on the upper side of the armature 4i and the other end secured to the lower end of a bolt 47' which is adjustably secured to the platform 5, normally holds the ar1nature in the position shown in Fig. l. The upward movement of the free end of the armature 44 is limited by its engagement with a screw 48 carried by an arm 49, which is secured to a block 50, carried in turn by an arm 51, which is clamped to two of the posts 6. A spring arm 52 is carried from the under side of block 50. The arm 52, by reason of its resiliency, normally bears against an adjustable contact member 53 carried by the arm 49. The outer end of the spring arm 52 is extended so that it will be engaged by the outer end of the armature 44 in its downward movement occurrhig whenit 1s attracted by the coil 43. The movement given to the arm 52 by this downwardmovement of the armature 4-4,- will cause the contact to lie-broken between the arm and the contact. member 53. A. red falpivotally connected to the upper side of the armature l4, and having its upper end guided by the platform 5 through an aperture in which it passes, carries a pair of adjustable collars, 55 and 55. l Vhen the armature 4.4- is at tractcd by the coil 43 and the rod 54. is moved dowi'nvard, the collar 55 will engage with dog 38, move it out of engagement with the ratchet wheel 25, and at the same time the collar 55 will engage the offset end 37 of the pivoted member 36 and through it more the pawl 35 out of engagement with the ratchet wheel 25. thus freeing the ratchet wheel 25 from its engagement with the dog 38 and pawl 35 for a purpose to be hereinafter determined.

A rod 56 extends upward from the plat form 7. The yoke member 5'? of a clutch surrounds this'rod. The voice member 57 has apawl 5d pivoted to it. The inner end or the pawl 15 sharpened and normally on gages the rod 56, as is clearly shown in Fig.

'ing mechanism out the lamp.

3, by reasonof the. fact that the outer end overbalances the inner end. A rod 59 extends upward from the cross head 18 adjacent the rod 56 passing through an aperture formed for the purpose in the outer end of pawl 58. Collars and. (51 are adjust-ably secured to the rod 59 at opposite sides of the pawl 58. When the cross head 18' and thereby the rod 59 is moved upward, the clutch 57 ollers no resistanceto the movement of the rod 59, the rod 59 passing loosely through the aperture in one end of the pawl until the underside of he pawl 58 is engaged by the collar 61, at r which the upward movement of the cross head 18' carries the clutch 57 with it. The downward movement of the cross head 18, and consequently of the electrode 16, is limited, however. by the engagement oi the collar (.10 with the upper side of the pawl 58; this engagement causes. the pawl 58 to grip the rod 56 more firmly.

In order that the clutch 57 may be released from its engagement with the rod 56 and the cross head 18' be lowered Whenever it heeomes desirable to do so, I have provided a cross head "2 of insulating materiel which slides upon the run 56. This cross. heed mounted upon the upper end of an tu'icrating XOll 63. The lower end of this rod passes through apertures formed for the purpose in platform 7, annular memher 8 and plate 10 and is )rovidcd at its 7 lower end with button 6 by which it can be grasped. .A catch normally holds the cross head 62 elevated in the position shown in Fig. 3. Upon pulling this cross head'doun upon the yoke 51' the locking' engagement. between the clutch and the rod'fili will be broken and the cross head 20 and parts connected thereto can then be lowered.

1 cylindrical casing 66, which may be formed out of sheet metal. extends between the platforms and "4' iuclosing the operat- 7 Another cylindrical casing: 67', of somewhat greater diameter than the casing 66, extends from the annular member 8 upward somewhat above the platform '5. casing 67 is turned in to form a flange 6'7 which is removably clamped against the under side of the annular member 8 by screws 68. The casings 66 and 67 are cured together by means of one or more pipeuir conduit'membel's 69, which extend between apertures formed in the casings 66 and .57. Air for ventilating the interior mechanism of the lamp passes through the bores of these tubular members 69.

The (liiierence in the diameters of the cusings (36 and (37 results in the formation of an annular space or chimney through which the heated gases or vapors from the are be- W961i the electrodes 13 and 16 can escape The lower end of the outerfrom the lamp. As is clearly shown in. Fig. l, the outer edge 1 of cap or top 1 is turned down so as to form hood which prevents moisture or dirt from entering the annular space between the casings 66 and 67.

Lugs 70 which depend from the under side of the annular member 8 are formed with threaded apertures through which screws 70. pass. These screws detachably secure in place a globe 71 which is formed of transparent or translucent material. such as glass. Spaces 2 exist between the top of the globe 71 and the annular member 8 through which the air ncl'zessary for the proper operation of the are may enter. The products of combustion from the are, mixed with a certain amount of air which enters through the spaces 72, pass upward through the tubular "passage formed by the flange 8 into the space between the platform 7 and the annular member 8, and thence through the annular space between the casings (S6 and 67, finally leaving the lamp through the space between the outer edge of the casing 67 and the cap or top 1.

Brackets 73 secured to the under side of. the cap or top 1 hold a resistance coil 7-1. A bushing 75 carried by one of the posts (3 has a sliding electrical contact with the rack bar 2l'and through it With the electrode 16.

For a proper understanding of the circuit connections of the lamp reference should be had. to the diagram shown in Fig.

6. Referring to the diagram, a conductor 76 extends from the binding post to the lower electrode 16 of the lamp. One terminal oi the coils 26, which are in series with one another, is connected to the line 76, at

the point 7TH The other terminal of the coils 26 is connectcd to the contact member 39. One terminal of the resistance conductor 74 is connected to the line 76 at the point 78. The other terminal of the resistance conductor 74 is connected to the plate 49 by a conductor 79. A conductor 80 couuccte, the plate 4-1 with line 7) the point 81. A conductor connects the binding; post 3"With one terminal of the ma uet L3. A. conductor 84 connects theplate o2 with the line 82 at the point 85. The other terminal of the coil 43 is connected to the plate l0 by a conductor 86.

The movable parts of the lamp mechanism are shown in the drawings and diagram in the jiositions they occupy when the lamp is out of circuit. When the binding posts 3 and 3 are connected in a propel opera ing circuit, currentnvill flow from the binding post 3 through the conductor 82, conductor Sl, plate 52, contact member 53, plate 49, line 79 to the po nt fill; thence the current will divide. one branch flowing through the resistance couductm: 74 to the line 76, and thence to terminal 2-3, and the other through the conductor 80, plate 41,

was

'As soon as the armature 'lh windings same time the contact screw 40, late 39, windings of the coils 26 through tlih line 76 to the terminal 3. The passage of 'current t-hrough the windings 26 will energize them and cause them to attract the armature 30, hen the armature 30 is attracted the pawl 35 will engage the ratchet wheel 25 and rotate it in the direction shown by the arrow in Fig. 2. Near the inner limit of the movement of the armature 80 the arm 42 will engage the plate 39 and move it away from the contact screw 40. This will break the circuit through the electr0-magnets 26, which will be denergized and allow the armature 80 to return to its original position. The movement of the wheel 25 in the opposite direction to that indicated by the arrow in Fig. 2 will be prevented at this time by the dog or pawl 38.

30 moves outward the plate 3.) will by its resiliency again move into contact with the screw 4-0, thus re'energizing the magnet coils 26. The armature 30 will again be attracted and the wheel 25 given a further movement in the direction indicated by the arrow in Fig. 2. The rotation of the ratchet wheel 25 causes a corresl'ionding rotation .of the spur-gear wheel 7 24 in a direction which elevates the rack bar 21, and consequently the electrode 16. This intermittentenmgization of the magnet coils 26 and s'tcpdw-stcp rctation of the ratchet wheel 25 is continued until the elecagainst the electrode 13. current will begin to flow from the terminal 3 through the conductor 82, windings of the electro-magncts 4-3, con ductor 86, plate 10, electrode 13, electrode 16, conductor 76 to the terminal :3. The passage of current through the windings of the clcclro-nmgnet 4- will cause it to attract the armature ll. 'hcn the armatm'e at is attracted the downward movement of its free end moves the contact plate 52 away from the contact member 53,- This bl'OflhS the circuit which includes the resistance conductor Tel, and the one which includes 01', the magnets 36. At the downward ngovcn'icnt ol' the rod 5 will cause the collar to move the dog 38 out of engagement wilh the ratchet whccl. In 'a similar manner-the collar 55 will engage the cxlcnsion 237 of the arm :36 and thcrcby move the vpawl 3? out 01" cugagcmcnt with the wheel 2.7, thus 'lrceing the Wheel 3., which will bcgin lo rolalc un dcr the weight oi" the bar 21 and parts carricd lhcrcby, in a dircclion opposilc to that l indicalcd by the arrow in Fig. As the l electrodes '13 and It; scparalc an arc is l drawn bctwccn thcm the rod 51 begins l to descend the collar til will movc away from the pawl 58 which will lhcrcby clamp l the rod 56 between it and the yolcc member 57. Allcr a movement ol' the rod :"lfitequal i to the play of the pawl 58 between the coltrode lo. strikes \Vhcn this occurs lars and 61, the collar 60 will strike against the upper end of the pawl'58- As this engagement operates to more firmly force the inner end of the pawl 58 into engagement with the rod 59, the downward movement of the rod 59, and thereby of the electrode 16, is checked. It will thus be readily seen that the separation of the electrodes 13 and 16 occurring after their contact is always equal to the play of the pawl 58 between the collars and 61, and in consequence the are struck after each feedin operation with any given adjustment of the collars 60 and 6] is always of a constant length. llhen the How of the current through the windings of the clectro-magnet 43 is interrupted in any ture 44 will be moved upward by the spring 46, allowing the spring contact 52 to engage the contact member 53. If after or at the time at which this occurs the terminals 3 and. 3 are connected in a suitable circuit the electromagnets 26 will be energized and deenergized in the manner hcreinbefore described until the electrodes 13 and 16 again engage. As the rod 55) moves up, the collar (51 will engage the under side of the carry it and the yoke member 57 upward a distance equal to the dill'erence between the distance separating the ends of the electrodes 13 and 16 at the beginning of the feeding operation and the player the pawl 58 through the collars 60 and (31. .When currentbcgins to flow again through the windings ot' the electro-magnct 43 the armature 44 will again be attracted and the electrodc 16 will again separate from the cleclrode 1:3 drawing an arc of a predetermincd length. i i

ll. hasbeen trodc 16 can be employed in character which wastes away so slowly that a .lccding operation of the lamp is not required durim the normal period of operalion. lien, however, it becomes necessary or desirable to employ a, lamp in. which the electrode may be led at intervals as it wastes away. it is only necessary to employ means for slim-t-(.'i1'cuiting or otherwise decnergizing the windings of the electro-magnet 43 whenever a feeding operation is neccssanv.

Most of the products 'ofcombustion from the are between the electrodes 13 and 16 are carricd "up by the draft created by the heat of the arc through the tubular member 8' into the space between the platform 7 and the annular member 8, and thence through the annular space bctwccn the caslugs (to and (l? and the lamp when they are discharged into the at mospherc through the space between the end of the casing (57 and the cap. The casing :=li(ll members (ill and (37 may be regarded as harming a (llllll)l(\--\\'2lll((l vcrlical annular manner the armapawl 58 and found that a consuming eleclamps of this upper end of the i casing.- The space or chamber between the walls this casing forms achimney pas sage through which the are products are carried by natural drafts. The member 7 forms a horizontal partition which prevents the are products from passing'into the space in which the electrodemoving mechanism is located. e

More or less of the products of the arc may, condense upon the interior parts of the lamp. In order to remove this condensed deposit the screws 68 may be loosened and the casing 66and 67 removed from the lamp, whereupon the various parts of the lamp may be -readily cleaned.

I have found that where the positive electrode is formed out of any conducting material,v stich as copper or the like, in order to revent a rapid destruction of the electrode y oxidization or otherwise, it is necessary that the electrode be so arranged that it will not be heated to too high a temperature by the arc.

In the'lamp h'ereinbefore described and illustrated I have formed-the positive electrode 13 out of a copper pencil or rod con- 'nected to a plate also made of copper or other material which is agood conductor of heat. In consequence of this the heat generated at the arc end of the pencil is rapidly conducted along the lcngthof the pencil to the plate 10. As the plate 10 has avery considerable heat-radiating or dissipating capacity the heat which is thus conducted away from the pencil 13 to the plate 10 is rapidly dissipated. This insures the temperature of the pencil 13 being maintained at a much lower point than would be the case if the plate 10, which is both a good conductor and a good radiator of heat, were not employed; The heatgdissipating-capacity of the electrode should not, however, be ,;.:'jncrcased beyond certain limits, at least with many substances which may be employed in the consuming negative electrode, as they give off fumes which will condense m large amounts upon the positivcelectirodc if it is too cool. These fumesare in many cases more or less non-conducting and when condensed on the electrode interfere in various ways with the proper operation of the lamp. It willof course be understood that the pen- ('il 1? and plate 10 connected thereto is only one form of non-consuming electrode having a proper heat-dissipating capacity and that this feature of my invention can be embodied in other forms.

of the pencil which is but poorly conducting The annular space 15 formed at the lower,

endof the positive electrode between the pencil 13 and insulating jacket 15 is of advantage as it prevents the formation of a slag which might otherwise be created and which might cause the agglomeration of the end of the pencil and jacket along. with some of the material condensed from the arc.

While I have hereinbefore described and illustrated in detail one embodiment of my invention, it is not intended that my invention shall be limited to this particular embodiment'as it will be apparent to any one skilled in the art that many changes may be made in the form of my invention without departing from its spirit.

What I claim as new and desire'to secure by Letters Patent of the United States, is,

1. In an arc lamp, a movable electrode, a feeding mechanism therefor comprising a member moving with said electrode, a stationary rod or post, a clutch includin a yoke surrounding said rod or post, an a pawl normally engaging, said rod and ex tending between stops carried by said member whereby a predetermined movement of the'member in one direction causes a corresponding movement of the clutch relative to the post and the clutch serves to limit the movement of the member in the 'oppositedirection, and manually actuated means for. moving said clutch relative to said rod in the direction opposite to that in which the clutch is moved by saidmember.

2.. In an arc lamp, an electrode feeding mechanism comprising a rod or bar, an arc length limiting clutch mounted thereon and normally free to/move in one direction only, and means for engaging said clutch to move it in the oposite direction.

3. In a are lamp, a rod or bar. a clutch comprising a yoke surrounding said rod or bar','"hnd a pawl pivoted to the yoke, means for engaging one end of the pawl. to release the clutch from the rod to move it in one; direction, and means fur engaging the yoke to move the clutch in the opposite direction.

4. In an arc lamp, an arc length limiting clutch, a member upon which it ismonntcd. a connection between the clutch and the feed mechanism of the lamp whereby the movement of the feed mechanism in one direction will move the clutch with it. while a predetermined movement of the feed mechanism in the otherdirection will cause the clutch to engage the supporting member and limit the movement of the feed mechanism in said opposite direction, and means for rendering the engagement between the clutch and the supporting member inoperative.

5. In an arc lamp, a pair of electrodes, a feeding mechanism therefor comprising a movable rack bar, an electrode moving with said rack bar, a second electrode, a gear wheel engaging saidrack bar to move it and the Winding of which is in series with said the action of gravity,- an intermittently actu- 111g means are rendeied inoperative. arted electromagnet for rotating saidgear In witness whereof, I have hereunto set wheel, means connecting said electromagnet my hand this 7th day of November, 1903.

JOHN T. H, DEMPSTER.

thereby move the electrodes together against novement of the raelgbar after said connect-- l0 electrode and said gear Wheel, means actu- I ated by the passage of current between the W1tnesses: electrodes for rendering said connectlng Ii means inoperative, and means limiting the HELEN ORFORD.

BENJAMIN B. HULL, i

Images