US1662434A - palmer - Google Patents

Description

M. W. PALMER CONTROL MECHANISM Filed Jan. 4, 1927 March 13, 1928.

2 Sheets-Sheet 1 INVEN TOR. WM.

BY M ATTORNEYS.

March 13, 1928.

M. W. PALMER coNTRoL MECHANISM Filed Jan. 4, 1927Y 2 Sheeis-Sheet 2 I N V EN TOR.

A TTORNEYS.

Patented Mar. 13, 1928.

UNITED STATES MERVYN w. immuun, or NEW YORK, N. Y.,

AASSIGNOB. TO PARAQMOUNT FAMOUS LASKY CORPORATION, OF NEW YORK,'N. Y., A CORPORATION OF NEW YORK.

CONTROL MECHANISM.

. Application iled- January 4, 1927. Sferial No. 159,010.

My invention broadly relates to automatic electric control devices and has for one of its objects the provision of automatically operating controlling mechanism whereby the voltage in a line may be maintained within very close limits, or, stating it 1n another way, automatically operating controlling mechanism governed bythe resistance in the circuit being controlled and arranged so as to maintain theresistance in the line within certain predetermined limits. While my improved apparatus is capable of numerous applications such as electric furnace installations, automatic electric elevator operation, search-lights, arc-lights :for

medical uses, projection machines and spotlights, it will, for the sake of clarity, be described with specific reference to spot-lights. .In a spot-light, as is well known, current is passed between spaced electrodes, and in f the carbon arc, that is to say arcs employing carbon electrodes, the carbon itself is the source of light, while in the high intensity arc the carbon acts as a holder for the real source of light, which is a small body of luminous gas. In both types' of arc, however, it is necessary to effect a'periodic adjustment of the electrodes in order that the arc voltage may be maintained within pre- 3o determined limits, or, stating it another way, the resistance across the electrodes must be maintained substantially constant,`

for best` results.

With the spot-lights employed in moving picture studio and theatre work, vit is customary to adjust/the electrodes b hand, the adjustment being made at the Wi of an foperator whose judgment must be relied upon. In studio work where a great many 40 spot-lights may be in use at the one time, it is customary to employ one operator for each machine, which of course imposes a heavy operating expense uponeach machine, and inasmuch as the human element in such cases must be relied upon, results are not always what may be desired. j

To avoid the annoyance and expense incident to the old method as just outlined of effecting the proper adjustment of the arc, I provide means applicable tofcarbon arcs as well as high intensity-arcs wholly auto` matic in its operation and controlled by the arc voltage whereby a variation in this voltage beyond certain prescribed limits will effeet a restoration of the electrodes to a predetermined relation and lre-establishment of the proper'arc voltage.

More specifically 1n invention contemplates the provision oi a reversible electric motor mechanically and electrically connected' to the electrodes to be "controlled, whereby upon an increase or -decrease in the arc voltage the motor will be energized to effect rotation of the same in the proper direction to in turn move the electrodes in the proper direction to restore or re-establish normal operating conditions.

In the accompanying drawing illustrating the application of ymy invention to a spotlight of the carbon arc`type, as well as high intensity arcs, X

Fig. 1 is a wiring diagram of my invention;

Fig. 2 is a part sectional elevational view of the apparatus which may be employed in the commercial use of the invention;

Fig. 3 is asection through Fig. 2 taken on the line 3 3 thereof;

Fig. 4 is a section through Fig. 2 taken on the line 414; v

Fig. 5 shows my invention high intensity arc;

F F ig. 6 is a section on the line 6-,6 of

Fig. 7 is a wiring diagram modified as to the diagram of Fig. 1; and

F ig.,8 is a Wiring diagram of a still further modification.

Referring to the drawings in detail and first of all to Figs. 2, 3 and 4, l desi ates a lamphouse which may be of usua con struction. Mounted within the lamphousc on suitable guides 2 is a carriage 3 carrying the electrodes 4 and 5. The electrode 4 is carried in a holder and the electrode 5 in a holder 7,1 the holders 6 and 7 in turn beapplied to a ing threaded upon a lrod 8 mounted for rotation but held against Ilongitudinal movev.ment in the'carriage. The threaded ortion 9 oi the rod 8 which receives the ho der 6 is threadedoppositelyto the portion 10 carrying the holder 7, so that rotation of the rod 8 will effect movement of the holders Cin opposed directions.

Mounted on the under side of the lamphouse is a platform, shelf or other sintlilo ' holding t able support 11 'fon a reversible electric motor 12, the armature shaft of whlch isA designated 13.. i

The armature shaft 13 carries a worm 14 meshing with a worm wheel 15 carried on a stub shaft 16. The shaft 16 1s connected lby a universal joint 17 to a stub shaft or rod 18 having telescopic connection to a rod 19 connected by a universal joint 20 to the threaded rod 8 carrying the electrodes.

The worm Wheel 15 is free onv the shaft r16, but a driving connectiornv is normally maintained between these two members by a clutch. This clutchisfillustrated in Fig. 4, and `from this Vfigure it will be seen that the lower side of the worm wheel 15 is'pro- The jointed connections above described .and the clutch mechanism just referred to provide .a `drive from the motor 12, to the rod 8, and rotation of this rod will, it is obvious, adjust the electrodes 4 and 5 relatively and in a direction depending uponthe direction of rotation of the motor.

In operation of the spot-light it is desirable to adjust the electrodes longitudinalv ly of the lamphouse, that is, to vary. thev distance between the` electrods and the lens 26. This adjustment is eiected by sliding the carriage 3 along the guides 2, by means j of a rod 27 provided for that'purpose; this l adjustment eingveffected without disturbthe drive between the motor 12 and4 8,' due tothe universal joints above' described, while the telescopic connection be tween he rods 18 and1-9 permits of this adjustment without varying the position of the arc vertically. y 'f n j Referring to the wiring diagram bt Fig. 1, it will be seen that the armature 28 of the motor 12 is connected across two branchl circuits designated 29 and '30, the circuit 29 being provided with fixed resistance 31 while the circuit 30 is provided with variable resistance 32. The electrodes 4 and 5 of the -arc are in the branch circuit 29.

The field of the motor is designated 33 'and as illustrated .is connected across the velectrodes 4 and 5.

The `operation vof my improved control `mechanism so Ifar as its electrical features areconcerned and so far as itsautomatic operatlon 1s concernedjis as follows, assuming that the electrodes 4 and 5 are in contact with eachother and that current is flowing through the branch circuits 29 and 30. Owing to. the arrangement of the resistances 3l and 32, there Will be a diiierence in potential across the terminals of the motor 12 to cause the armature 28 thereof to be energized and hence the` motor to be rotated. The rotating of this armature 28 through 4the mechanism described in connection with Figs.,2, 3 and 4 will cause the rod 8 to rotate in the proper direction to effect a separation of the electrodes 4 and 5. When these electrodes have separated a predetermined distance, the increase in resistance, due to the separation' of the electrodes 4 and 5, will establish a balance between the branch circuits 29 and 30. In other words, there will be no dii'erence in potential at the terminals of the motor 12 with the result that the motor armature 28 will come to rest. As soon as thekelectrodes 4 and 5, or rather the positive electrode 4, has burned away or disintegrated due to the arcwacross these electrodes suiciently to, so to speak, upset the balance between the branch circuits 29 and 30, a difference in potential across the terminals of the motor 12 will again occur, with the result that the arma ture, will be rotated, but this time in the opposite direction, so as to move the electrodes 4, and 5 toward each other until a balance has been reached again. Consequently, it will-rbe seen that no hand manipulation of the electrodes 4 and `5 is necessary in order to maintainthevoltage across the electrodes 4 and 5 within predetermined limits, with the result that the spotlight will be operated at a substantially constant voltage.

It will .be understood that-the variable resistance 32 isonly necessary for the initial setting of the device, no manipulation of this resistance being necessary aiter the devlce has once been adjusted, the entire operation of my improved apparatus being automatic.

AIt will beL understood also that if the switch (not shown) controlling the supplying of power to the electrodes 4 and 5 be opened when the electrodes are out of contact, al closing of this switch will cause current to iiow through the motor 12 in a directionto cause the motor to move the electrodesv 41 and 5 toward each other. Inasmuch as under these conditions the arc has not `been struck, it will be obvious that the 'motor will continue to so rotate until the electrodes engage eachother or make contact. When the electrodes contact, themotor vwill reverse in direction, separating th'e electrodes 4'and 5, to strike an arc and will continue to rotate in a direction to separate the electrodes until the latter have beenflseparated the correct distance asdetermined by the initial setting of the the medium of an electric motor.

machine. Thereafter conditions, so far as operation is concerned, are as has been described above.

As I have mentioned above, a spot-light has been illustrated and described in detail for illustrative purposes only, inasmuch as my invention has many applications, some.

of which have been enumerated above. For example, I have mentioned lan electric furnace as one possible application of my invention, and it Will be obvious to those skilled in this art that in such a case my invention may be employed to control the resistance and hence the voltage of the electric circuit of the furnace by inserting in this circuit a pair of contacts in which the contact pressure may be controlled by the motor 12. In other Words, in such a Case it is merely necessary to substitute such contacts for the electrodes 4 and 5 shown in Fig. 1, the resistance of the circuit instead of varying with the change in distance between the electrodes 4 and 5, varying with or being varied by the pressure of the 'two contacts upon each other.

As above pointed out, my invention is adapted for application to high intensity arcs, and such an application has been illus trated in Figs. 5 and 6.

Referring to these two figures of the drawing, 34 and 35 designate, respectively, the positive and negative electrodes of a high intensity arc. The positive electrode 34 is rotated continuously as is customary through In the present case, this motor is designated 36 and corresponds to the motor 12 of the embodiment of my invention already described. Also, as is customary, the positive electrode 34 is fed forward, that is to say, in a direction toward the negative electrode 35. The negative electrode 35, as distinguished from the positive electrode, is stationary so far as rotation is concerned but is adapted to be adjusted relatively to the positive electrode 34 by the electric motor 36, as will be described presently in detail. In other words, as applied to high intensity arcs, my invention provides means for maintaining the proper arc voltage at all times as in the case of the carbon arc already described.

The positive electrode-34 is mounted on a suitable stand 37 to whichV is secured a bracket or other support 38 carrying the electric motor 36. The negative electrode is mounted in a suitable head 39 supported by an arm 40 carried by the member 37. This part of the apparatus is conventional and will not be described in any great detail for this reason.

The armature shaft of the motor 36 is designated 41 and is provided with a VWO1-m42 shown clearly in Fig. 6, this Worm meshing with a Worm Wheel 43, the latter being mounted on a sleeve 44 which surrounds a ing clutched under ordinary conditions to the worm wheel 43 by teeth 46. The shaft 45 carries a gear 47 rigidly secured to the shaft and meshing with a gear 48 carried on a short shaft 49 shown in Fig. 6. The upper end of this shaft is provided with a bevelled gear 50 meshing with a bevelled gear 51 which in turn meshes with a bevelled gear 52 carried at the lower end of a flexible or jointed shaft 53. This shaft is provided with a universal joint 54 and has a telescopic connection with a shaft 55 which in turn is provided with a universal joint 56 and is connected by this universal joint to a shaft 57 provided With worms 58 and 59, these worms meshing with Worin gears 6() and 6l, respectively, actuation of these worm gears effecting movement of the negative electrode 45 longitudinally. We have, therefore, a driving connection from the motor 36, that is to say, from the armature shaft 41, to the negative electrode 35 whereby rotation of the motor Will eect adjustment of the electrode. The drive for the positive electrode .34 which, as above (noted, is constantly rotated and fed forward intermittently, comprises a gear v62 on the upper end of the shaft 45 meshing with bevelled gear on the end ofla drive shaft 64. The opposite end of this drive shaft is provided with a gear 65 meshing with a bevelled gear 66, the latter driving a bevelled Gear 67 on the lower end of a shaft 68. This shaft is connected by a universal joint 69 to a shaft 70, the latter being connected by a universal joint 71 to a shaft 72 on the upper end of which is a bevelled gear 73 meshing With a gear 74 connected to the positive electrode 34 so that rotation of the gear 74 through the gear train just described by means of the motor 36 Will cause the positive electrode 34 to be rotated.' The feed for the electrode 34 is the conventional form and hence will not be described in detail.

The operation of this device is similar to that described in connection with the carbon arc illustrated in Fig. 2, the Wiring diagram for the motor 36 being arranged the same as shown inl Fig. 1. In other words, assuming that the switch (not shown) supplying current tothe motor 36 is opened vertically extending shaft45, the sleeve bewhen the electrodes 34 and 35 are in the position shown in Fig. 5, closure of this switch will effect rotation of the motor in a direction to feed the electrodes, particularly the electrode 35, in a direction to bring Ythese two electrodes in contact, whereupon,

due to the drop in resistance on account of the contact of the two electrodes, the motor will be reversed automatically, the arc will trodes independently of the motor 36, the` sleeve 44 is pushed upwardly against the'` action ofthe spring 75 so as to disengage the teeth 46 from the face of the worm gear' 43.

i This sleeve is keyed or otherwise rigidly secured to lthe shaft 45 and the shaft may be rotated so as to cause the electrodes to be adjusted. y, A

The wiring.l diagram of Fig. 7 is a modification of the diagram of Fig. 1. Referring to this iigu're of the drawing, the motor 12, the position of which corresponds to the motor 12of Fig. l, is an alternating current 'motor and has its rotor This motor is provided with two field windings 7 6 and 77 of diiferent resistances, each iield when energized alone producing rotation of the motor in a different direction. It will be obvious from an inspection of this diagram that one or the other of these field windings will be energized when'` an unbalanced condition exists in the circuit. due to improper spacing of the electrodes' 4 and 5, and depending upon which field is energized, the motor will be caused to rotate in a corresponding direction, thereby actuating the electrodes 4 and 5 in a vdirection to restore balanced conditions again.

`While the two specific embodiments of my i invention as above described are suitable for 35. o

certain lclasses of arcs, that is to say, arc lights used forcertain classes of work. it may be desirable or necessary in some instances to use a larger motor than I have found necessary to use lin the forms illustrated. In such event I propose to employ two motors, one of which may be avery powerful motor, relativelyspeaking, and adapted to actuate the necessary mechanism for effecting the desired electrical conditions. The other motor in this embodiment of my invention may be termed a pilot or control motor, and las it will have practically no work to do except the mere opening and closing of a switch, this pilot or control motor may be of very low capacity, the throwing of the switch by the pilot motor controlling the circuit of the heavy motor to cause the same to operate. Inasmuch as the particular switch mechanism and othermechanical features of this embodiment ofv my invention are of minor importance. I have deemed it sutlicient to merely illustrate this feature-of my invention by way of a diagram, which is the diagram of Fig..8.

Referring to the wiring diagram of Fig. 8, it will be seen that the electric motor 12, lwhich is provided with twofield windings 7 6 and 77, respectively, is vmechanically connected to a reversing switch 78, this reversshort-circuited.. v

ing switch controlling the circuit if) a reversible electric motor 79. This motor,

as above pointed out, may be of any neces-Y sary size but is intended'for heavy duty, and it is to be understood will Vbe mechanically connected to the device or devices to be controlled, such as the electrodes 4 and 5, which have been illustrated in this diagram merely for clarity of description and illustration. The reversing switch 78 is adapted to make contact with either contact 80 or 81,'as the case may be, depending upon conditions across the electrodes or other devicesv being controlled. In short, this diagram is intended to illustrate an application of my invention to an insta-llation wherein the devices 4 and 5, which are to be controlled, are adapted to be actuated bythe reversible motor 79, and as above pointed out, inasmuch as the devices represented by the electrodes 4 and 5 might be of such a nature as to require a heavy-duty motor for their actuation,'I have provided the heavy-duty motor 79, which is controlled by the relatively light-duty motor 12. The only work to be performed by the motor 12, as -will be apparent, is actuation of the reversing switch 78. Here, then, I have provided an apparatus wherein lthe direction of rotation of the motor 12 is controlled by the resistance across the members 4 and 5, the

direction of rotation of the pilot or control have provided means for maintainingl the voltage in a line within4 close limits, and` while my invention is capable of many applications, I have illustrated and 'described the samev in connection with a carbon arc spot-light and in connection with a high intensity arc. It will be seen also thatI have provide several embodiments of my invention, so far as theelectrical side thereof is concerned, thel diagram of- Fig. 1 showing al motor with but one field winding but with the armature winding so arranged that the direction of rotation of the motor is selected by the resistance across the electrodes 4 and 5. In other words, speaking now of a carbon arc spot-lighthwhen the electrodes are burned awayso that the resistance across the electrodes is increased to a point where there is a voltage drop across the electrodes belill) lll) trodes to strike vthe arc and continuing this separation of the electrodes until the voltage across the'same is brought within the predetermined limit.

It will be seen also that in Fig. 7 I have varied this arrangement, in that the motor is provided with two field windings, the excita# tion of one field causing the motor to rotate in one direction, while the excitation of the other field causes the motor to rotate in the opposte direction, the excitation of these fields being selected by the resistances across the electrodes 4 and 5. In other words. this f embodiment of the invention will operate to maintain the voltage across the electrodes 4 :md5 within the predetermined limits, as in the case of the diagram of Fig. 1.

It will be seen also that in Fig. 8 I am able to obtain the same results electrically and mechanically, and while in this figure I have modified the wiring diagram of Fig. 7, in that I have added the motor 79 thereto (the motor 12 merely controlling the circuit to this motor), it is to be understood that the' motor 79 could be added to the diagram of v Fig. 1, if desired. n

The armature and field connections in theY diagram of Fig. 1 obviously may be interchanged, if desired.

It will be obvious that many changes may be made lin the construction illustrated in the accompanying drawing as above described, wlthout eparting from the spirit of the invention, and accordingl my invention is not to be limited to t e precise form here shown and described.

What I claim is:

1. In combination, a pair of co-operating electrodes, two branch circuits, said electrodes being in series with one of said circuits, a reversible electric motor having its armature connected across said branch circuits, a field for said motor connected across said electrodes, and means for mechanically connecting said electrodes to said motor, whereby a variation in the voltage of the current flowing in the circuit containing the electrodes will effect rotation of the motor larmature to actuate the electrodes and reelectrodes inserted in series with one 0 saidv branch circuits, an electric motor mechanically connected to said electrodes for effecting relative adjustment thereof, said motor comprising an armature connected across said branch circuits and' a field connected across said electrodes, whereby the voltage across said electrodes will be maintained within predetermined limits.

3. In combination, two branch circuits, an arc light comprising a pair of electrodes inserted in one of said circuits, an electric motor comprising an armature ymechanically connected to said electrodes and adjustably connected across said branch circuits for determining the operating position of the electrodes, and a field for said motor connected across said electrodes.

4. In combination, a pair of branch circuits, an arc light comprising two electrodes inserted in series with onevof said circuits, an electric motor mechanically connected to said electrodes for adjust-ing the same automatically the armature of said motor being adj ustablyconnected across said branch circuits for determinin the o erating position of the electrodes, an the eld for said motor being connected across said electrodes.

This specification signed this 3rd day of January, 1927.

MERVYN W. PALMER.

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