US950000A - Arc-lamp. - Google Patents

Description

R. HEWSON.

ARC LAMP.

APPLICATION FILED JUNE 5, 190a.

Patented Feb. 22, 1910.

2 SHEETS-SHEET 1.

WITNESSES. INIZENTUR 35 fi JZUBERT HEWS'LZZSZ'.

A T T3? R. HEWSON.

ABC LAMP,

APPLICATION FILED JUNE 5, 1908.

Patented Feb. 22, 1910.

0 2 SHEETSSHBET 2v 0 lll l l l lllllh m e m x I U 4 1 l I YJTNEESEE': JNYENTUH HUBERT HEWSDAZ.

' BY @W I ATTY Annual 5 Gamma no m'm-umocuwmwnswumw. n c

UNITED STATES PATENT OFFICE.

ROBERT HEWSON, OF LYNN, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION 01? NEW YORK.

ARC-LAMP.

Specification of Letters Patent.

To all whom it may concern:

Be it known that I, ROBERT HnwsoN, a citlzen of the Domlnlon of Canada, residing at Lynn, county of Essex, State of Massachusetts, have invented certain new and useful Improvements in Arc-Lamps, of which the following is a specification.

My invention has reference to improve ments in arc lamps of the kind in which for the establishment of the arc and also at intervals during the feeding operation the two electrodes are forcibly brought together and are then separated by gravity to the arcing distance. In these lamps are ordinarily employed cathodes, which, in consuming, yield the gases or vapors which maintain the arc, while the anode is, as a rule, although not always, of a piece of metal of good conductivity of heat and electricity which, theoretically speaking, is not at all consumed, but which has proved in practice to become consumed at a slow rate whereby its arcing end becomes irregularly disfigured. terial which becomes fused at the arcing end, formingthere a. little pool from which the arc springs. In these lamps the inconvenience has been experienced that when the cathode, which is usually the lower electrode, is forcibly brought into contact with the anode, the two electrodes become wedged together, due sometimes to the irregularities of their end surfaces and sometimes to looseness of their mountings or guides, so that they become displaced laterally with reference to each other, and thus wedge together. If this happens the cathode, which in such lamps is arranged to separate from anode by gravity merely, is held locked to the same by the wedging action and cannot separate and the are cannot be formed, and the unduly great amount of current which is thus allowed to pass through the lamp is liable to injure the parts. Sometimes it also happens that the anode freezes to the cathode pool superficially, and the establishment of the are may be prevented for this reason also.

My invention is designed to overcome these difiiculties, and it consists in a weight bearing upon the cathode carrier, or to any part moving with the cathode, in such manner that when the cathode is forcibly thrown upward toward the anode, the weight will.

move with it, and will by its inertia move The cathode is usually made of a ma- 0 farther than the cathode itself, which is arrested by contact with the anode. This weight, dropping down to its original position, will act as a driver upon the cathode carrier, and forcibly separate the electrodes even if they have been rather tightly wedged or have frozen together. All this will more fully appear from the following detailed description with reference to the accompanying drawing, in which Figure 1 represents an elevation of the operating mechanism of an electric arc lamp of the kind to which my invention applies, with its circuit connections, the electrodes being shown separated; and Fig. 2 repre sents the same lamp mechanism in the condition when the electrodes have justcome into contact, the circuit connections being omitted.

Like numerals of reference indicate like parts throughout the drawing.

In the drawing 1 and 2 represent respectively a positive and a negative electrode of a luminous arc lamp. The positive electrode is shown in the form of a non-consuming copper rod having wing- like extensions 3 and 4, which pass through slots 5 in the walls of the fume-box 6. In these slots the wings of the electrode may be held in a fixed position, but, as here shown, the wings rest upon pins 7 projecting into the slots and thus normally support the wings a short distance below the upper ends of the slots, so

that the electrode 1 may rise a short distance by the impact of the electrode 2 and is then free to fall down this short distance when the electrode 2 drops away. A platform 8 supports the fume-box and from the upper side of the platform extends the chimney 9, it being understood that the platform has a wide opening registering with the upper end of the fume-box 6 and with the lower end of the chimney. In the drawing the chimney is shown as broken off. The negative electrode 2 is shown as supported and operated in a wellknown manner. A tube 10 passes vertically through the platform and through a guide tube 10 and carries at its lower end an arm 11 which terminates in a socket 12 in which the negative electrode is clamped. The tube 10 is guided at its upper end by means of a rod 13 which projects downward from a bracket 14 supported by a standard 15 which is mounted on a secondary platform 16 insulated from the main Patented Feb. 22, 1910.

platform 8. 17 and 18 are the lifting and holding clutches, of any usual construction. The function of the lifting clutch is to engage the supporting tube of the lower electrode and move it vertically until this electrode has come into forcible engagementwith the upper electrode. The function of the holding clutch is to cooperate with the support for the lower electrode so as to permit this electrode to drop a predetermined distance away from the upper electrode after the two electrodes have been brought into engagement by means of the lifting clutch. The lifting clutch is operated by a suitable regulating magnet having an armature 19 and an energizing coil 20, and this magnet is in turn controlled, so as to become energized after the two electrodes have come into engagement, and thus permit the separation of the electrodes for the establishment of the arc. The core of the eleciromagnet has attached to its yoke a stem 21 provided with a shoulder or collar 22, upon which the end of the pawl arm 23 of the lifting clutch 1T rests. ll' llGH the magnet is energized, the core is drawn upward, the lifting clutch is brought into operative engagement with the tubular portion of the carrier of the lower electrode and is then carried vertically upward until the lower electrode is brought into engagement with the upper electrode. The holding clutch 18 is illustrated as being of the usual floating tyne. normally locked to the tubular support of the lower electrode by means of the elongated spring Eat, the upper end of which is hooked to a portion of the bracket 14 and the lower end to the pawl 25 of the clutch 18. Normally, this clutch rests upon the fixed stop 26, rising from the auxiliary platform 16. \V hen the lifting movement begins, the holding clutch travels with the electrode carrying tube 10 until it comes into engagement with a second fixed stop 27, which is arranged at some distance above the stop 26. The stop 27 arrests the movement of the holding clutch, which, how ever, permits the electrode supporting tube to continue its upward movement, since by the engagement of this clutch with the stop 27 the clutch releases the tube 10. lVhen the electromagnet is deenergized, the lower electrode and its supporting tube begin to drop, butthe holding clutch immediately again grips the tube 10 and is carried downward with it until it again strikes the stop At this time both the clutch and electrode are brought to rest. A dashpot controls the speed of descent of the lower electrode; the movable member 28 of this dashpot being connected to the stem 21, while the stationary member 29 is fixed to the platform 8.

In Fig. 1 the parts are shown in the normal running position, which is also the position when the current is turned 05 from the lamp. In addition to the main regulating magnet there are two auxiliary magnets 30 and 31, the first having a coil which is in series with the electrodes and the other a coil which is in series with the coil of the main magnet. To the respective cores of the auxiliary magnets are attached contacts 32 and 33, which, when they engage, place a shunt about the coil of the electromagnet 31 and connect the coil of the main magnet across the line in series with a resistance When both magnets 30 and 31 are deenergized, the contacts and 33 engage, while during the substantial deenergization of magnet 81 and the energization of magnet 30 the contacts are out of engagement. llhen current is thrown on, the contacts 32 and being in engagement, a circuit is established through the main electromagnet, while the electromagnet 31 remains deenergized. The lower electrode 2 is therefore aised in the manner described, until it engages with the upper electrode. Current now flows from the electrodes in series with the coil to electromagnet 30, and this magnet, being energized, lifts the contact out of engagement with contact 33, thereby connecting the coil of magnet 31 in series with the coil of the main magnet. The current through the main magnet is now so diminished that its armature drops, freeing the tube 10, which now also drops, carrying with it the lower electrode. As the arc lengthens, magnet 30 becomes weaker and magnet 31 stronger, until a point is reached when the contacts 32 and are brought together; whereupon the main magnet is again operatively energized and the lower electrode is lifted as before.

The lamp so far described is essentially the same as that shown in an application filed by Richard Fleming on December 28, 1905, Serial No. 293,590, or the one shown in an application filed by Cromwell A. ll. llalvorson, J r. on March 7, 1907, Serial No. 361,051; and l have here described this lamp only as exemplifying the character of lamp to which my invention applies, namely; as one in which one of the electrodes is brought into forcible contact with the upper electrode and is then allowed to drop away from the same for the establishment of the arc. As has heretofore been pointed out, in such lamps the electrodes sometimes wedge together or freeze together, and my invention is designed to insure the establishment of the are if such wedging or freezing occurs. For this purpose I use a weight 35, which rests upon the lower electrode carrier, and in the case here particularly shown it rests upon the arm 11, being for this purpose shaped like the link of a chain, as is clearly shown, the opening of the link being wide enough to slip over the boss 36 which is sometimes made in one piece with the arm 11, and to which the electrode l l i) 2, and when the contact is made, the lower electrode is suddenly arrested; but the weight 35, which by that time has attained a considerable momentum, continues to rise upwardly and may rise, as shown in Fig. 2, throughout the whole length of the loop or link openin At that moment the electrode carrying tube 10 is released from the clutch l7 and has now tendency to drop down so as to establish the are between the electrodes. If it should happen, as it frequently does, that the electrodes are wedged together or are frozen together, the weight will nevertheless fall down from the position shown in Fig. 2 to the position shown in Fig. 1, and will strike the lower electrode carrier a heavy blow that will free the lower electrode from the upper and will allow it to descend by gravity for the establishment of the arc. The weight 35 may take any desirable shape and may be mounted on any part of the structure that moves with the lower electrode. The weight should be made heavy enough to surely free the lower electrode from the upper, but it need not be made heavier than this.

The invention is applicable to all kinds of arc lamps in which the arc is established by two movements of at least one of the electrodes, viz. a contacting and a separating movement, irrespective of the character of the electrodes.

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

1. In an arc lamp, a means for separating the wedged or frozen electrodes, consisting of a free weight impacting one of the electrode carriers in the direction of its arcstrilring movement.

2. In an arc lamp, the combination of an arc-striking electrode having two opposite movements, with a weight thrown by one of the movements and starting by its fall the reverse movement.

In an arc lamp, the combination of a stationary and of an arc-striking electrode having two movements, with a free weight thrown upward by one movement of the electrode and aiding by its fall the other movement.

4:. In an arc lamp, in which one electrode is positively moved in contact with the other stationary electrode and is then released for gravitational arcstriking movement, a free weight moved upwardly by the contact movement of the electrode and released to assist by its weight the arc-striking movement.

5. In an arc lamp, the combination of a stationary electrode and a movable electrode, the latter being positively actuated to contact with the former and then released for gravitational arc-striking movement, with a free weight adapted to be thrown upward by and beyond the contact movement and which by its descent starts the arc-striking movement.

6. In an arc lamp, the combination of a stationary electrode, a movable electrode, means for positively actuating the latter to move in contact with the stationary electrode, means for releasing the movable electrode from the actuating mechanism for gravitational arc-striking movement, and a weight arranged to reinforce the gravitational movement.

7. In an arc lamp, the combination of two electrodes in vertical alinement, means for lifting the lower electrode into engagement with the upper electrode and then releasing it from the lifting mechanism, and a weight resting upon the lower electrode carrier and guided for free vertical movement above the same.

In witness whereof, I have hereunto set my hand this 27th day of May, 1908.

ROBERT I-IEWVSON.

IVitnesses BENJAMIN F. REAGIN, IVALTER L. BALLARD.

Images