US1617314A - Series-operated studio arc lamps - Google Patents

Description

Feb. 8, 1 927. 1,617,314

T. HALL SERIES OPERATED STUDIO ARC LAMPS Filed May 20. 1920 INVENTOR 7 z700/? HALL A1". QRNEY Patented Feb. 8, 1927.

UNITED STATES PATENT OFFICE.

THEODORE HALL, OF BROOKLYN, NEW YORK, ASSIGNOR TO THE SPERRY GYROSGOPE COMPANY, OF BROOKLYN, NEW YORK, A CORPORATION OF NEW YORK.

SERIES-OPERATED STUDIO ARC LAMPS.

Application filed May 20,

This invention relates to are lamps, and more specifically to automatically controlled arc lamps adapted to be connected to operate in series for bank lighting. In my copending application, Serial No. 377 ,743, filed April 30, 1920, for projector lamps, I described in detail an automatically controlled arc lamp adapted for use in motion picture projection. An object of the present inven- 1 tion is to devise a method of operating such or similar lamps in series for use in motion picture producing studies, or for other purposes. An important advantage of so connecting the lamps is that where several lamps are required and the voltage available is in excess of a multiple of the value required to operate one of the lamps, as for instance, where the voltage available is 110 and each lamp requires 50 v., by connecting two lamps in series, a rheostat capable of effecting a drop of 10 v. at the normal current employed will sufiice to care for both lamps, whereas otherwise a separate rheostat capable of effecting a drop of 60 v. is

required for each lamp.

The principal object of the invention, is to devise a method of operating the lamps whereby an enormous saving in energy which would otherwise be dissipated in heat is'etfected.

A further object is to greatly reduce the weight and bulk of the lamp units by this reduction in the amount of resistance necessary.

Referring to the drawings wherein I have shown what I now consider to be the preferred form of my invention:

Fig. 1 is a side elevation of an automatically controlled arc lamp.

Fig. 2 is a wiring diagram showing a plurality of lamps arranged in accordance with my invention. Q

In Fig. 1 the lamp is shown as comprising two portions 1 and 2 secured together as b 5 means of screws 3, but insulated from eac other by means of insulation 4. The portion 1 is shown as supporting a carriage 5 slidably mounted-on a guide rod 6 and having threaded engagement at 7 with a rotatable rod 8. Guide rod .6 is preferably also rotatable and is provided with a keyway 9. A gear 10 slidably mounted on rod 6 may have a projection, not shown, engaging in keyway 9. The said gear meshes with a gear 11 1920. Serial No. 382,817.

fixed on an electrode holder 12 rotatably carried by carriage 5. The positive electrode 13 may be gripped by said holder adjacent its rear end, and may project through a guide 14 near its burning end 15. Fixed on rods 6 and 8 are ratchets 16, 17 adapted to be actuated by pawls 18, 19 secured to a carriage 20 which is in turn connected by a link 21 to a motor 22 for reciprocation up and down.

Preferably motor 22 runs continuously during the operation of the lamp. and pawl 18 is in constant engagement with ratchet 16, so that rotation of rod 6, gear 10, and gear 11 will efiect continuous rotation of electrode 13. Pawl 19, however, is preferably normally disengaged from ratchet 17, so that it normally reclprocates without actuating ratchet 17. Energization of a magnet 23 is adapted to throw pawl 19 into engagement with ratchet '17. This will effect rotation of rod 8 to advance the carriage 5 and electrode 13. Energization of magnet 23 is effected through the third electrode 39 in response to the position of the end 15 of electrode 13.

Portion 2 of the lamp may be provided with a carriage 24 slidably mounted on a guide rod 25 and in threaded engagement with rod 28. The rear end of the negative electrode 26 may be gripped by said carriage 24.- while the forward end protrudes through a guide 27. Rod 28 may be provided with an elongated pinion 29 meshing with a gear 30 on the same shaft 31 as bevel gear 32 which in turn meshes with bevel gear 33 on shaft 34. The said shaft is divided and insulated at 35 so as not to act as a short circuit between the two portions of the lamp. The opposite end of this shaft is provided with a ratchet 36 adapted to be actuated by pawls 37 fixed on the rec1pr0- catory carriage 20. The said pawls are normally disengaged from ratchet 36, but are brought into engagement therewith by a yariation up or down of the current passlng through electromagnet 38 so as to rotate rods 34 and 28 to move electrode 26 toward or away from electrode 13.

The apparatus thus far descrlbed is disclosed in great detail in my aforesaid copending application.

In order to effect a rapid striking of the arc I have shown rod 28 as having long hearing portions ermitting longitudinal sliding ofsaid rod t rough its bearings 41, while the lower end 42 of the rod constitutes the core of a solenoid 43 fixed to the lamp. A spring 44 engaging a stop 45 at one end and at the other a plate 46 against which the end of the core 42 bears rotatably, normally presses rod 28 upwardly and this in turn maintains electrode 26 in contact with electrode 13. Solenoid 43 may be in series with the are so as to be energized throughout the period that the current is flowing. As soon as the current is turned on and flows from one electrode to the other by reason of their physical contact, the core 42 will be attracted y solenoid 43 to draw rod 28, carriage 24, and electrode 26 downwardly to the position shown, thus striking the arc.

As shown in the Wiring diagram in Flg. 2, several of such lampsA, B, and C-may be connected in series for operation. he

current entering through supply line 45.

flows through coils 38,43, electrode 13, across the arc 46, through electrode 26 of lamp A, conductor 48, and through the similar elements of the other lamps B and O successively and back through line 49.

As stated, the positive and negative electrodes of the lamps are normally in contact so that a complete circuit through the electrodes is established as soon as the current is turned on and energization of all of the solenoids 43 is efiected and the are im- 'med'iately drawn in all of the lamps. The

the lengths of the several arcs 46.

' motor 22 for continuously actuating the rethe other in response to the resistance in the circuit will thus adjust the length of arc in lam A so as to maintaina constant amperage 1n the entire circuit and consequently across all of the arcs. The magnets 38 controlling the feeding of the negative electrode of lamps B and C are, on the other hand, connected in shunt with their respective lamps. Thus the strength of these magnets will becontrolled in accordance with the length of arc in their respective lamps, andbeing adjusted. to a redetermined neu tral point, will control t e feeding of their negative electrodes toward or away from the positive whenever the arc len h tends to vary. In this way, coil 38 of amp A will 1113111173111 constant amperage across all of the arcs and an arc length in lamp A in accordance with the voltage in the supply lines 45, 49.

To regulate the arc length in lamp A then I may provide means for re ulating the *voltage of the. lamp circuit. 0 viously such means may be either manually or automatically operated. The means here shown comprises a rheostat 50 interposed in the supply line. The arm 51 of this rheos'tat may be connected to a gear 52 for actuation. A pinion 53 meshing with said gear may be provided on the shaft 54 of a motor 55. The field 56 of said motor may be connected across the supply lines as shown, while the 1 armature 57 thereof may be connected through conductors 58, 59 to the blades 60, 61 of a reversin switch 62. The switch is shown in neutral position so that no current will be supplied to the armature 57. The rear arm 63 of the switch may constitute the armature of an electromagnet 64 shunted across the supply lines 45, 49 between the rheostat and the lamps. An adjustable tension spring 65 may be provided to oppose the action of magnet 64'upon armature 63. Turning of screw 66 in fixed member 67 will regulate the tension of spring 65 so as to hold the switch inthe centralized position shown when the voltage is of a predetermined value. An increase or decrease in the voltage will. result in the turning of the switch onits axis 68 to throw switch blades 60, 61 into engagement'with contacts 69, 70 on the one hand, or 71, 72 onthe other. Thus on the one hand current will flow from the positive side through conductor 73, contact 69, switch blade 60, conductor 58, armature 57, conductor 59, switch. blade 61, contact 70, conductor 74 to the negative side and the motor will turn in one direction to actuate arm 51 of rheostat 50 to throw in more resistance, while on the other hand the current would flow through conductor 73, contact 72, blade 61, conductor 59, arma ture 57, conductor-58, blade 60, contact 71, and conductor 74 to the negative side to turn the motor in the opposite direction to decrease the resistance. In this way the voltage supplied to the lamps may be maintained substantially constant and this. in turn will maintain a substantially constant arc length in lamp A.

The third electrode 39 is shown as connected' through conductor 75 and electromagnet 23 to line 48, so that as the crate: end 15 of the positive electrode tends to recede by reason of consumption, the flame 76 will touch said third electrode, completing a circuit through electrode 13. The magnet 23 will thus be connected to shunt with the arc and will effect the feeding of the positive electrode as pointed out. i

It should be noted that while I have shown three lamps to illustrate my invention, it'is obvious that two lamps instead of three may he used; the lamp C being omitted and conductor 48 of lamp B being connected directly to supply line 49. On the other hand, it is equally obvious that several additional lamps may be added to the series. It should also be noted that although separate striking solenoids 43 are shown for the lamps the. lamps would operate successfully without such solenoids as shown in my prior application 377,743. Of course in such event no one of the lamps would draw an arc until all drew the arc. This would cause no difiiculty provided the lamp having the shunt coil 38 should strike before the lamp having the series coil 38. Such action may of course, be insured by making the normal .rate of feed of the first mentioned lamp.

somewhat faster than the rate of feed second mentioned lamp.

In accordance with the provisions of the patent'statutes, I have herein described the principle of operation of my invention, to-

of the gether with the apparatus, which I now. consider to represent the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative and that the invention can be carried out by other means. Also, while it is designed to use the various features and elements in the com bination and relations described, some of these may be altered and others omitted without interfering with the more general resultsoutlined, and the invention extends to such use.

Having described my invention, what I claim and desire to secure by Letters Patent lsz 1. In combination, a plurality of seriesconnected arc lamps, means for automatically regulating the voltage supplied to said lamps, means controlled by a coil shunted across each lamp for effecting the feeding of one of the electrodes thereof, means controlled by a coil in series with said lamps for effecting the feeding of the other of the elec trodes of one of the lamps, means controlled by separate coils shunted across each of the other of the lamps for eflecting the feeding of the other of the electrodes of said other lamps, and means whereby said secondnamed means are controlled by the position.

of the arc flame.

2. In combination, a plurality of serieslating means for controlling the arc length of said one of the lamps.

4. In combination, a plurality of seriesconnected arc lamps, means responsive to the position of one of the electrodes in each lamp for effecting the feeding of such electrodes, electromagnetic means controlled by the current in all of the lamps adapted to control the arc length'in one of the lamps, electromagnetic means in shunt with the others of said lamps for controlIin the arc lengths thereof, and means for maintaining constant the voltage in said lamps.

5. In combination, a plurality of arc lamps connected in series, means whereby variations in the amperage of the circuit are taken up by one of the lamps to maintain constant the amperage in all of the lamps, and means for maintaining constant the arc length of said one lamp.

6. In combination, a plurality of arc lamps connected in series, voltage controlled means for feeding an electrode in one of said lamps, means for feeding an electrode in another of said lamps and a voltage regulator and a current cont-rolled element for controlling said second mentioned feeding means.

7. In combination, a plurality of arc lamps connected in series, a current responsive coil in series with the are on one of said lamps, means controlled thereby for effecting the feed of said lamp and thereby regulating the current supplied to all of said lamps, a voltage coil on each of the other of said lamps, and means controlled thereby for effecting the feeding thereof in accordance with the arc length.

In testimony whereof I have aflixed my signature.

THEODORE HALL.

Images