US996392A - Arc-lamp. - Google Patents

Description

J. H. ALLEN.-

ARG LAMP.

APYLIOATION FILED m1111116, 190e.

996,392-, lPatented June 27, 1911.

v 4 2 SHEETS-SHEET 1.

LH. ALLEN.

ARG LAMP. APPLICATION FILED Mums, 1906.

Patented June 27, 1911.

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mem'frg J .An/141my UNITED srArEs Parana" OFFICE.

JOSEPH H. ALLEN, OEGHICAGO, ILLINOIS, AsSIGNOPaIBY MESNE ASSIGNMENTS, To GENERAL'ELEOTRIC COMPANY, A CORPORATION OE. NEW YORK.

ARC-LAMP.

`To all whom it may concern:

Be it known that I, JOSEPH II. ALLEN, citizen of the` UnitedI States, residing at Chicago, i-n the county of Cook and State of Illinois, have invented a certain'new and useful Improvement in Arc-Lamps, of which the following is az full, clear, concise, and exact description.

My invention relates to an electric arc lamp, and has for its object to protect the carbon-lifting magnet from abnormal currents which would burn out the'y coils thereof. Considerable difficulty has been experienced heretofore in arc lamps due to such burning out of t-he feed magnet coils, which is often ycaused by the clutch member, after being raised by the magnet core to lift the upper carbon and establish an arc, allowing-the upper carbon .to slip down into engagement with the lowerl carbon, thereby'greatly decreasing the resistance of t-he circuit and permitting an abnormally heavy current to flow through the lifting magnet.

My invention contemplates the provision.

of a .thennostatict'rod expansible upon the 4passage of an abnormal current through the lifting magnet, adapted to short circuit said magnet,.and permit the armature and clutch to drop into position to separate the carbons when the lifting magnet is again energized. I preferably employ a thermostatic rod connected in series with the feed or lifting magnet, said rod, upon the passage of an abnormally heavy current in the circuit,

'expanding to close a pair of contacts conabout the liftingv trolling a short circuit magnet, which thereupon releases its core or armature and allows the .clutch member to fall int-o position to grasp the upper carbon and reestablish the arc when thelifting magnet is again energized. l The contacts referred to also close at the same time a short circuit about thethermostatic rod, and as soon 'as lthe rod Vcools and contracts, it separates the contacts referred'to and opens vvthe short circuits, whereupon the lifting magnet is energized and separates the carbons to reestablish the arc.

f A feature of-imy'invention consists in the provision` of means `adapted to avoid any ".:possibil-itybf the thermostatic rod closing itsshort circuit in case said rod should be-` Specification of Letters Patent. Patented June 2'?, 1911, Application filed March 16, 1906.

Serial No. 306,363.

perature in the lamp. To this end I employ a thermostat independent of the circuit of the lamp, which permits the first thermostat to respond to an abnormally heavy current in the lamp and close the short circuit, but which prevents the said first mentioned thermostat, whenv it responds to an abnormally high temperature closing said short circuit.

I will describe my invention more particularly by reference to the accompanying drawings, wherein- Figure l is a front elevation of a lamp equipped with a protecting device for the lift-ing magnet embodying my invention; Fig. 2 is a longitudinal sectional view of the protective device; Fig. 3 is a plan view thereof; Fig. I is a plan of t-he lamp, from view of a modified form of' protective device embodying my invention and provided with means for prevent-ing the thermostatic rod from operating its contacts to short circuit the lifting magnet when the temperature o f the lamp is abnormally raised; Fig. 5 is a sectional view on line 5 5 of Fig. 4,; and Fig. 6 is a `simplified circuit diagram ofthe lamp shown in Fig. 1. y

Similar letters of reference designate like parts throughout the several views;

The lifting magnet a of the arc lamp show'n in Fig.l 1 is provided .with the usual armature or core for operating the clutch b to separate the two carbons of the lamp. thermostatic rod c of metal is included serially in the circuitof the magnet a, and 1s secured at one end to a post c mounted upon an insulating base c2, the other end of said rod being connected to the lower end of a spring arm c3, said post and sprlng arm having suitable terminals upon-the under side of the block c2. The rod c when expanded, due to the passage of an abornal current in its circuit, is` adapted tomove the spring arm c3 into engagementwith a contact post c4- and thereby close a short circuit about the lifting magnet a, said contacts c3 c4 when closed also completing a short circuit around the rod c.

Referring to Fig. 6, the circuit of the lamp and its protective device will be readily apparent. rIhe normal circuit extends from the positive terminal of the lamp by way of conductor 1 to the spring arm c3, thence to rod c and post 0, through the lifting magnet a to the upper carbon of the lamp, and thence by w'ay of the lower carbon and conductor 2 to the negative terminal of the lamp. When no current is passed through the lamp, the carbons are in contact, as shown, butl when the circuit above referred to is completed, the lmagnet a is energized and draws up its core or armature, which operates the clutch Z) shown in Fig. 1, to separate the carbons and establish an arc. Now, it for any reason the clutch should accidentally release the upper carbon while the core is attracted and allow the upper car bon to fall into engagement with the lower carbon, the arc would no longer be present and the resistance of the circuit greatly decreased, whereupon the abnormally heavy current would flow through the circuit 1, 2 and, if permitted to ilow for any length of time would burn out the coils of the magnet a, The thermostatic rod c, being in the circuit, is heated and expanded by this adnormally heavy current, and moves the spring arm c3 into engagement with the contact post c", which is connected by conductor 3 with conductor 1, between the magnet a and the upper carbon, thereby short circuiting the magnet a, which allows its core t0- gether with the clutch, to fall into position to lift the upper carbon when the magnet a shall again .become energized. rllhe contacts c3 c4 when closed also short circuit the rod c by way of conductor, and rod c is allowed to cool. When cooled, the rod contracts and separates the contacts c3 c4, breaking the short circuit referred to and permitting current to flow through the magnet a, which draws up its core and separates the carbons to reestablish the arc. The rod c isv preferably adjustably secured to the post c', so that the distance between the contacts c3 c4 may be varied as desired, the rod c oit course being rigidly secured to the spring arm 0,3. Such adjustment may be secured in the manner most fully shown in Figs. 2 and 3 in which the rod c passes through or is otherwise secured to a set screw 05, said set screw being adjustable in the post c.

1n order to prevent any possibility of an abnormally high temperature of the lamp caused by theheat of the arc, from heating and expanding the thermostatic rod and closing the contacts ce c4, may employ the type of protective device shown in Figs. 4: and 5, which is provided with means vfor rendering the rod c ineiifectively responsive to such an abnormally high temperature.

I provide a rocking lever d connected at one side d of its pivot with one end of the thermostatic rod c, the other end of said rod being connected with a spring member e. A

second thermostatic rod 7 is connected at ceases one end with the lever d at the other side d2 of its pivot, being insulated therefrom by a suitable bushing, and 'the other end of said rod f is connected with the spring member e. The lever (Z is provided with a suitable ter minal underneath its supporting base, which would be connected with conductor 1 in the manner of spring .arm c3 shown in Fig. 6, and the spring member c is provided with a similar terminal connected with conductor 1 in the manner of supporting'post c of Fig. 6. An extension d4 of the lever d, which preferably lies parallel with the rods c, f, is provided with a normally-open contact d5 with which it is adapted to engage when the lever d is rocked by the expansion of the rod c, these contacts Z4 Z5 corresponding to the contacts c3 c4 shown in Fig. 6.

When an abnormally heavy current passes through the rod c and the magnet a, the rod c is heated and expands, rocking the lever d t0 closethe contacts Z4 d5. Since no current passes through the rod f, it will not be expanded and will cooperate with the spring member e to permit the rocking lever ci to close contacts Zt d5. In case, however, an abnormally high temperature is present in the lamp, both rods c f will be expanded and will move the spring member c to the left without, however, affecting the lever d.

ll claim 1. In an electric arc lamp, the combination with an arc-controlling magnet, of a circuit therefor, a thermostatic rod in said circuit adapted to respond to an abnormal current therein, a rocking lever connected at one side of its ivot with one end of said rod, a spring memer to which the other end of said rod is connected, a short circuit about said magnet closed by said lever when rocked bythe expansion of said rod, and a thermostatic rod connecting said lever at the other side of its pivot with said spring member to prevent the closure of said short circuit when the lamp temperature is abnormally raised.

2. In an electric arc lamp, the combination with an arc-controlling magnet, of a circuit therefor, a thermostatic rod in said circuit responsive to an abnormal current therein, 'a rocking lever connected at one side of its pivot with one end of said rod, a spring lever to which the other end of said rod is connected, an extension of said arm,

a normally-open contact adapted to be en-y gaged by said arm when said lever is rocked by the expansion of said rod, a short circuit about said magnetclosed by said extension and its contact, and a thermostatic rod insulated from said lever and connecting the -same at the other'side of its pivot with said spring member, both of said rods expanding upon an abnormal increase in the lamp temperature to prevent rocking of said lever.

3. ln an electric arc lamp, the combination with an arc-controllingimag net, of a tem perature of the lamp to prevent the opcircuit therefor', a rocking lever adapted eratlon of said lever. -10 when operated to close a short circuit about In .Witness whereof, I hereunto subscribe said magnet, and a pair of thermostatic y name this 13th' day of March A.'D.,1906. rods, one of said rods being included in said JOSEPH H. ALLEN. circuit to respond t0 abnormal currents and Witnesses:

operate said lever, both of said rods ojoerat-v RAY. -T. ALLOWAY,

ing in response to` any abnormally high BERT. S. YORK.

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