US508656A

US508656A - Electric-arc lamp

Info

Publication number: US508656A
Authority: US
Publication date: 1893-11-14
Anticipated expiration: 1910-11-14

Description

(No Model.) v

E- THOMSON. ELEOTRIO ARC LAMP.

No. 508,656. Patented Nov. 14, 1893.

Flill numms'h In! lllllilllillllll l l|ll% UNITED STATES PATENT OFFICE.

ELlI-lU THOMSON, OF SWAMPSCOTT, MAssACHUsETTs, ASSIGNOR TO THE THOMSON-HOUSTON ELECTRIC COMPANY, OF CONNECTICUT.

ELECTRI -ARC LAM P.

SPECIFICATION forming part of Letters Patent No. 508,656, dated November 14, 1893.

Application filed February 4. 1892. Serial No. 4203M. (N model.)

nected in multiple between constant potential mains from burning or injury due to excessive current caused by an abnormal arc. The invention consists in certain mechanism whereby the descent of the carbon or the feeding action of the carbon to a predetermined point, as when the carbons are fully consumed operates a switch which opens the circuit of the feeding magnet.

In the accompanying drawings Figure l is an elevation of a portion of an arc lamp embodying my invention, with circuit connections. Figs. 2, 3, 4, 5, and 6 show modifications. Fig. 7 is a detail of the feeding actuator.

The feeding magnet K is in derived circuit around the are E, E as shown in Fig. 1, said circuit being completed through a switch W which during the normal operation of the lamp is closed; The lamp may be a ribbon feed lamp in which a ribbon V suspends or holds up the upper carbon and its holder H and guiding frame, said ribbon going around a drum D which is gradually rotated by the action of an endless screw mechanism shown at S, said endless screw mechanism being actuated by the derived circuit magnet or feeding magnet on the presence of a slight increase from the normal electro motive force of the are. For this purpose the magnet K operates a pawl k and ratchet wheel M, Fig. 7 and this wheel actuates the worm and worm wheel feed, as shown in Fig. 1. The feeding mechanism is no part of the present invention as it is disclosed in my Patent No. 458,025 of August 18, 1891. The switch W is held closed during the normal feeding of the carbon, by engagement of the periphery of the drum D with the switch lever L. When, however, the carbon holder has descended to its lowest limit, a depression in the drum periphery comes opposite the engaging tooth on the switch lever and said tooth drops into the depression, opening the switch W and the circuit of the shunt magnet.

Fig. 2 is a diagram, showing a modified but typical arrangement, K being the feeding magnet and D the drum upon which the ribbon V Fig. 1 is wound and which rotates as the ribbon V and upper carbon are fed during the action of the lamp. An ordinary gearing and detent pawl are indicated as constituting the feeding mechanism. The small depression e arriving opposite the projection on the lever L will allow said lever to move under the action of its elasticity or spring to open the switch WV and at all other points the drum will hold said lever down and keep the switch W closed. This action of opening the switch is sudden as the projection is made with an edge which slips quickly into the depression, also made with a sharp edge. In order to enable the projection to freely pass out of the depression at e on the restoration of the parts as by the rotation of the drum D backward during resetting of the carbon after consumption, said projection is made in the form of a small hinged pawl P with a spring, as shown, which enables it to be set over or to pass by the edge of the drum and slip upon the periphery of the drum out of the depression c. This is a minor detail and the result may be accomplished in other ways.

Fig. 3 shows the switchW operated by the depression e in an ordinary carbon rod marked V, the lever L which controls the switch having a projection which drops into the depression at e on the rod V arriving at a predetermined position of descent.

In Figs. 4, 5, and 6 the switch opening lever pressed upward by the spring Z has on it a projection at l which as the drum D rotates during the descent of the carbon and the downward motion of the ribbon V finally slips into the cavity or depression e in the drum, the part Z being shown as just ready to drop into the depression, or just passing over the edge thereof, at which time the switch WV is opened and remains open so long as the parts remain in position. The downward tendency of the ribbon V acts against a coiled spring ltending to rotate the drum in the opposite direction. The tendency of the ribbon V to rotate the drum is so far in excess owing to the weight of the carbon holder and the carbon itself and its guides that the descent of 5 Vwinds up or coils up the spring T. On the insertion of carbons by raising the holder II the spring '1" reasserts itself and turns the drum D so as to keep the ribbon Vtense,and to prevent the projection on the leverL from to stopping such backward movement by engaging with the sharp edge of depression e, said depression has an offset inclined portion U and the lever L is pressed slightly laterally as indicated in the figure by the dotted lines and is then forced out of the depression (2 on the inclined surface. Thus the drum D may rotate backward so as to coil up the ribbon V without hinderance from the pin Zwhen dropped into the depression 6.

While I have indicated the switch as breaking only the circuit of the shunt magnet, it may be used to break the circuit of the entire lamp by arranging the connectors as indicated in dotted lines X Yin Fig. 3, the connectors a, 0, being inthat case omitted.

What I claim as new, and desire to secure by Letters Patent, is-

1. The combination with the rotary support for the carbon holder, having a depression, of 0 a circuit controller engaging with such support and means for impelling the engaging part of such controller into said depression.

2. In an arc lamp, the combination with the carbon holder, of a rotary support therefor having a depression, containing on one side an inclined surface, and a circuit controller having a projection engaging with said depression, substantially as described.

3. In an arc lamp, the combination with the carbon holder, of a rotary support therefor having a depression containing an inclined surface leading off to one side, and a circuit controller having a projection engaging with said depression, substantially as described.

4. In an arc lamp, the combination with the carbon holder, of a spring actuated drum, a ribbon wound on the drum and attached to the carbon holder, and a circuit closer adapted to be operated by said drum, substantially as described.

5. In an arc lamp, the combination with the carbon holder, of a rotary support therefor, and a circuit controller adapted to be operated by said rotary support, substantially as described.

ELIHU THOMSON.

Witnesses:

JOHN W. GIBBONEY, BENJAMIN B. HULL.