US593697A - Electric-arc lamp - Google Patents

Description

2 Sheets-Sheet 1.

(No Model.)

0. C. STIRLING. ELECTRIC ARC LAMP.

Patented Nov. 16,1897.

a a? a 9 y w fir y y n. J/ n Em i LE EEEEE (No Model.) 2 Sheets-Sheet 2.

U. G. STIRLING. ELECTRIC ARC LAMP.

No. 593,697. Patented NovLlG, 1897.

Nil-ED Stars arnnr Orrrcn.

CLARENCE C. STIRLING, OF HARTFORD, CONNECTICUT, ASSIGNOR TO EDMUND HUDSON, OF TEMPLETON, MASSACHUSETTS.

ELECTRIC-ARC LAM P.

SPECIFICATION forming part of Letters Patent No. 593,697, dated November 16, 1897. Application filed February 6, 1897. Serial No. 622,264 (No model.)

To aZZ whom it may concern.-

Be it known that I, CLARENCE O. STIRLING, of Hartford, county of Hartford, State of Connecticut, have invented an Improvement in Electric-Arc Lamps, of which the following description, in connection with the accompanying drawings, is a specification, like letters and figures on the drawings representing like parts.

This invention relates to electric-arc lamps of that class in which the rays of light therefrom are reflected upwardly and in which the arc is maintained in a fixed or predetermined position.

The invention has for its objects, first, to improve the construction of the carbon-feeding mechanism, whereby the carbons are antomatically fed toward each other to maintain the arc in a fixed or predetermined position 5 second, to provide an improved form or construction of actuator for said carbon-feeding mechanism, and, third, to improve certain details in the general construction of the lamp.

The invention consists in embodying in an arc-lamp certain feeding mechanism for the carbons, comprising ahollow shaft and a rod which enters and moves telescopically therein, said hollow shaft being externally screwthreaded and receiving upon it the lower carbon support, which rises and falls as said hollow screw-shaft is turned in one or the other direction, and said hollow screw-shaft being also internally screw-threaded and receiving within it the aforesaid rod, which is externally screw-threaded, and as said hollow screw-shaft is turned said rod will be moved up and down according to the direction of movement of said hollow screw-shaft, and the screw-threads are so arranged that as said hollow screw-shaft is turned in one direction the lower-carbon support thereon will be raised and the screw-threaded rod will be lowered, and vice versa, and said rod is connected with the upper-carbon support, and consequently said upper-carbon support will move with said rod. The pitch of the screw-threads vary, so that the carbons will move toward each other at different rates of speed, which is proportioned to the consumption of the respective carbons, so that the arc can be maintained in a fixed or predetermined position.

The invention also consists in an actuator for the carbon-feeding mechanism consisting of a motor, comprising a field-magnet which is included in circuit in series with the carbons, and a rotary armature which is included in a normally open branch circuit, and a circuit-closer or switch is provided for said branch circuit, which is operated by a device controlled by the field-magnet of the motor, which device is responsive to variations produced by the varying resistance of the arc-as, for instance, a supplemental armature may be provided for'said field-magnet which is connected with said switch or circuit-closer, and said supplemental armature has a retractor which is overcome by the attractive force of the field-magnet when but little resistance is produced by the are, but when said resistance is increased to a considerable extent said retractor will overcome the attractive force of said field-magnet, re-

tracting the armature, and thereby causing the switch or circuit-closer to close said normally open branch circuit.

The rotary armature of the motor is connected with the carbon-feeding mechanism, and when the switch or circuit-closer of the branch circuit is open said rotary armature Will remain at rest, but when said switch or circuit-closer is operated and the branch circuit closed said rotary armature will revolve and operate the carbon-feeding mechanism.

Figure 1 is a side elevation of an electricarc lamp embodying this invention. Fig. 2 is a front elevation of the same, parts thereof being broken away for clearness. Figs. 3 and 4 are details to be referred to, and Fig. 5 is a diagram of the electric circuit as arranged'in my improved arc-lamp.

A and B represent, respectively, the lower and the upper carbons. The lower carbon is placed in a socket formed in a holder a and securely held in place by means of a thumb-screw a. The holder a is formed with a shank a which projects down through a bushing a and a spiral spring a encircles said shank a the lower end of which rests upon a shoulder formed in the bushing and the upper end bears against said holder, and the action of said spring is to thrust the lower carbonholder an upward. The bushing a is mounted in a similar bushing a of insulating material which is fixed in the center of a disk Z). The disk Z) is mounted to slide vertically upon a guide post or bar 0, and is formed with a depending sleeve Z), which embraces said post 0 and is insulated therefrom by means of a lining b of anysuitable insulatingmaterial.

The disk Z) is also formed with a depending boss Z), which is internally screw-threaded to engage the externally-screw-threaded shaft (Z, which latter is revolved in the manner and by the means to be hereinafter described, and acts as a feeding serew to move vertically the disk Z) and lower carbon carried thereby. The post 0 is fixed at its lower extremity in a base 0, in which base is also journaled the lower extremity of the feeding or screw shaft (Z. The screw-shaft (Z has mounted loosely thereon at or near its lower end aworm-gear 0, upon which is mounted a pawl (Z that e11- gages a ratchet-wheel (Z fixed to said screwshaft (Z, and said worm-gear c is engaged by a worm f, fixed to a shaft 1), which is herein shown as the shaft of the rotaryarmature of an electric motor. The shaft D is caused to rotate at certain times, as will be hereinafter described, and through the medium of said worm f and worm-gear c the screw-shaft (Z will be rotated in a direction to feed the disk Z) and parts borne by it upward a short (listanee and until said shaft D ceases to revolve.

The upper carbon B is placed in a holderg and is secured therein by means of a thumbscrew g. The holder 9 is formed upon or secured to a cross-piece to one end of which is secured a depending guide-rod g and the post 0 is made hollow to receive within it said guide-rod which slides up and down telescopically. The upper end of said cross-piece has secured to it one end of a threaded rod g", the threads formed thereon having one half the pitch of the threads formed upon the exterior of the screw shaft (Z. The screwshaft (Z is made hollow and interiorly screwthreaded to receive within it said threaded rod 9, which is moved up and down by the turning of said hollow screw-shaft (Z. It will thus be seen that when the screw-shaft (Z is rotated, either by the rotation of the shaft D or otherwise, the upper carbon B will be fed downward at half the rate of speed at which the lower carbon is fed upward, which relation is in proportion to the consumption of the respective carbons and results in maintaining the are in a fixed position.

A short shaft Zl is-journaled in the base 0, which has fixed thereon a pinion h, that meshes with a pinion 7L2, fixed to the screwshaft (Z, and said short shaft 71. projects down through the base 0, and its lower projecting end is squared to receive a wrench or other implement by means of which to revolve the shaft (Z by hand, and so facilitate the adjustment or replenishing of the carbons A andB.

The supporting-rods 1' t" are secured at their lower ends to a disk of wood or other suitable non-conducting material, and said. disk is hollowed out upon its upper face to receive the base 0. The upper extremities of the supportingrods i '2' are united by a crosspiece 2, of wood or other non-conductingniaterial, and to said cross piece an eye 1'' is secured by means of which the lamp may be suspended.

Upon the disk Z) is mounted an are forming or striking magnetj, thearmature y" of which is attached to a lever f pivoted at one end to a post or upright support j, the free end of said lever being forked and disposed to rest upon the holder Ct. Circuit contact-sprin Z 7;- are secured to a block 7" of insulating material sccured to the disk Z).

the arc-forming magnet] and their free ends straddle and slide along upon the rod 1 To the upper end of the rod 1? one wire of the main circuit is attached, the other wire of said circuit being attached to the upper end of the rod '1 To the lower end of the shank a of the carbonholder is attached a wire 7.1 which connects with the coils of the arc-forming mag net 7'.

The spring (1. tends to hold the lower carbon up against and in contact withthe upper carbon until the arc-forming magnet is energized, when its armature will be drawn downward, carrying with it the lower carbon and moving said lower carbon a distance sufficient to produce and establish the arc properly between the two carbons.

The motor which serves as the actuator for the feeding mechanism comprises a fieldmagnet G and a rotary armature 1'), and said field-magnet Gis included in the main circuit, in series with the carbons, and the rotary armature is included in a branch eir' cuit, and said rotary armature is secured to or mounted upon the shaft D, to which the worm is secured. Z are the two members of a circuit-closer which is provided for said branch circuit containing the rotary armature and which normally holds open the branch circuit and when operated closes it, and when said branch circuit is open said rotary armature is at rest but when said branch circuit is closed said rotary armature revolves.

It is desired to operate the circuit-closer by a device responsive to variations in the cui= rent produced by changes in the resistance of the arc, and as a device of this character I provide the field-magnet G of the motor with a supplemental armature Z, which is pivoted. at 50, and which is connected by a link 51.wit-h one of the members of said circult-closer. The field-magnet G is included in the main circuit in series with the carbons, and the coils of said iield-nmgnet are connected by means of a wire Z- with a bracket 'm, which is in contact with the base 0. The wire Z' is also connected with the commutatorbrush a of the motor. The opposite end of the coil of the lield nagnet G is connected by a wire Z to a binding-post 0, which sup- The contact-springs 7. are connected by a wire 7& with the coils of ported upon the frame of the field-magnet G and insulated therefrom. The post 0 is also connected by a wire 0 with the fixed member Z of the circuit-closer, and said wire 0 is part of the branch circuit, in which is included the rotary armature D of the motor. A wire 0 connects the movable member Z of the circuitcloser with the commutator-brush n of the motor, and the said wire 0 also forms a part of the branch circuit within which the rotary armature of the motor is located. A wire 13 connects the post 0 with the rod 1;.

The circuit of the lamp is as follows: Starting at the connection at the upper end of the rod 72 the current passes down through the rod 1" to the brushes 7t through the wire It to the arc-forming magnet, and thence through the wire 70 to the lower and upper carbons, and down the rods 9 and g and shaft d and rod 0 into the base 0, and from the base 0 through the wire Z to the field-magnet G,

thence to the post 0, and then by wire p to the rod 1 and to the line.

The passing of the current through the field-magnet G causes the same to magnetically attract and move the supplemental armature Z in a direction to move the member Z of the branch circuit-closer, so as to open the branch circuit, and during the operation of the lamp this switch or circuit-closer is held normally open until the resistance due to the consumption of the carbons and strengthening of the arc is such that the strength of the field-magnet is reduced to such an extent that the member Z of the circuit-closer, which serves as a retractile spring for the supplemental armature, will overcome the strength of the field-magnet and will cause said armature Z to retract and close the branch circuit. The rotary armature of the motor will then be caused to rotate, and through the medium of the worm f and worm-gear e the shaft d will be revolved and the disk b, carrying the lower carbon, willbe fed upwardly, while the upper carbon will be fed downwardly sim ultaneously at half the rate of speed at which the lower carbon is fed upwardly. Then the resistance is reduced at the are, which will occur when the carbons approach each other, the strength of the field-magnet G will increase to a sufficient extent to attract the armature t open the branch circuit, and thus stop rotation of the armature, and consequently the feeding of the carbons. This condition exists until the resistance is again increased, due to the consumption of the carbons and lengthening of the arc, when the operation will be repeated.

Upon the rods 2' and c" is mounted a reflector-disk 0', which is placed in the inverted position shown, and supported between nuts 8, fitted to the threaded portions of the rods 2' and 2". The bottom of the disk r is arranged so as to come below the arc and to reflect the rays of light therefrom upwardly against a ceiling from which the lamp may be suspended, and the light is reflected downwardly from the ceiling and diffused uniformly about a room or the like, so as to give the best illuminating effects. The disk 1" is formed with a centrally-located opening r through the bottom thereof, which is lined with a bushing r of asbestos or other suitable heat and electrical insulating material, through which the lower carbon projects to the upper side of the disk r. Openings 1" r are also provided, which permit of the passage freely therethrough of the shaft 01 and post 0.

It will be seen that the field-magnet G not only serves its purpose as the field-magnet of the motor, but also acts as a relay to control the movements of the supplemental armature Z movement of which to and from the field magnet opens and closes the circuitcloser.

The rotary armature of the motor is in multiple with the field-magnet, and the voltage it will receive will depend upon the length of the winding .upon the field and upon the amount of current passing in that winding.

I claim- 1. In an electric-arc lamp, an actuator for the carbon-feeding mechanism consisting of a motor comprising a field-magnet in series with the carbons having two pairs of poles, a rotary armature between the poles of one pair, a normally open branch circuit therefor, a circuit-closer for said branch circuit, a supplemental armature for operating said circuit-closer, located opposite the poles of the other pair responsive to variations produced by the varying resistance of the arc, substantially as described.

2. In an electric-arc lamp, feeding mechanism for the carbons comprising a feedingscrew for each carbon, one of which is made hollow and internally screw-threaded to receive the other, means for turning said hollow screw-shaft by hand, and an actuator c011- sisting of a motor comprising a field-magnet, and a rotary armature, the latter being operatively connected with said hollow screwshaft, substantially as described.

3. In an electric-arc lamp, the combination with actuating mechanism, of feeding mechanism for the carbons comprising a hollow shaft externally and internally screw-threaded, the internal threads having one-half the pitch of the external threads, said shaft receiving upon it the lower-carbon support,and receiving within it a screw-threaded rod which is connected with the upper-carbon support, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

CLARENCE C. STIRLING.

Witnesses:

CLAYTON P. CHAMBERLTN, FRANK B. SMITH.

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