US583957A - Electrostatic influence-machine - Google Patents

Description

N0 Model.) 3 Sheets-Sheet l.

, E. THOMSON.

ELECTROSTATIC INFLUENCE MACHINE.

No. 583,957. Patented June 8,1897.

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- (No Model.) 3 Sheets-Sheet 2.

E. THOMSON.

ELEOTROSTATIG INFLUENCE MACHINE.

Patented June 8, 1897.

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(No Model.) 3 Sheets-Sheet 3.

E. THOMSON. ELII'GTRQSTATIG INFLUENCE MACHINE.

No. 583,967 Patented June 8,1897.

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ELIIIU THOMSON, OF S\VAMPSCOTT, MASSACHUSETTS, ASSIGNOR TO THE GENERAL ELECTRIC COMPANY, OF NEW YORK.

ELECTROSTATIC INFLUENCE-MACHINE.

SPECIFICATION forming part of Letters Patent No. 583,957, dated June 8, 1897.

Application filed January 5, 1897. Serial No. 618,030. (No model.)

To aZZ whom it may concernthe fluid included in the casing by means,- Be it knownthat I, ELIHUTHOMSON, a citisuch as an incandescent wire of platinum, zen of the United States, residing at Swampwithin the casing itself. scott, in the county of Essex, State of Massa- In the drawings annexed, Figure l is asec- 55 chnsetts, have invented certain new and usetion of a machine embodying my invention. ful Improvements in Electrostatic Influence- Fig. 2 is a side elevation of one of the plates Machines, (Case No. 503,) of which the folof its excitingportion. Fig. 3shows one form lowing is a specification. of working generating-plate. Fig. at is an- My present invention relates to improveother form. Figs. 5 and 6 are respectively 60 1o ments in' static generating-machines, which a vertical section and a horizontal section, are capable of producinghigl1potential elccpartly in elevation, of a modified form of tric discharges or currents by electrostatic machine. Figs. 7 to 10 are details of the colinduction. Some of such machines are the lectors. Fig. llillustrates the commutating well-known Holtz or Toepler-Holtz or \Vimsarrangement for reversing the connections 65 hurst machines. In my invention I employ to the work circuit in case the machine is the principles upon which such devices are giving currents in the wrong direction or of founded to construct a novel machine espewrong polarity in its discharge, for the purcially adapted to givea considerable outputof pose of saving disconnection of the termihigh-potential current or discharges. nals, since the reversal may be made while 70 2o Briefly my invention consists in associating the machine is in action. Fig. 12 shows the in the same apparatus two machines, one of reversing arrangement separate and also which is purely an eXciter for the other, which shows how it is used as a variable spark-gap latter is purely the producer of useful disdevice. charges. Fig. 1 is a plan view, partly in section, of a 7 5 By my invention there is less liability to machine provided with an outer surrounding back discharges producingreversal of polaricase K K, which may be made of thin wood ties, and the machine therefore keeps "its poor which maybe made of a frame with panels larity more constantly. of glass or rubber. This case, however, may

My invention also has for one of its objects be dispensed with if atmospheric conditions 80 to provide a convenient means for reversing permit, as when the surrounding air is very the direction of current in machines of the dry. Running through the center of the easgeneral class described. Such machines are ing is a shaft carried in suitable bearings or liable to sudden reversals undersome condiuprights B B and carrying a pulley p on one tions of use, while for some classes of work, end. The shaft serves to revolve and sus 85 such as exciting Crookes tubes, the discharges tain a number of plates 1 to 5, of glass, hard are preferably in the same direction. For rubber, or otherinsulating material. Oppothe purposes pointed out I so arrange the resite one side of the plate, the face of which versing-switch that it may be used not only is seen in Fig. 2, is mounted an equalizer e e, for its ordinary functions, but also for adsustained in a fixed position from the journal 90 j usting the spark-gap distance where Leyden B, or in a position which is capable of adj ustjars or condensers are employed in conjuncment angularly around the axis. The equaltion with the machines. izer may be of metal or wood or other mate- My invention consists also in feeding into rial, but in the latter case a metal strip or the casing of the machine a suitable neutral wire runs along to make it conducting, and 5 gas, preferably deoxidized air, at a temperaat each extremity opposite the plate a numture sufficientl y high to prevent precipitation ber of metallic points are carried, which serve of moisture. I by this means prevent the the purpose of the ordinary connectors in formation of ozone and maintain the insulastatic machines, thereby equalizing the tion of the apparatus. charges on opposite ends of the diameter of the I co It is within my invention to maintain the revolving plate 1. The particular disposition temperature and simultaneously to deozonize of the points may be as is usual in such machines-that is, directed toward the revolving plate; but I prefer the constructions which are pointed out in Figs. '7 to 10. These will be further described and their advantages stated.

In Fig. 2 the equalizer combs or collectors c e are connected together electrically and mounted opposite the surface of the revolving plate at diametrically opposite positions and at an angle with other combs or collectors c 0, also diametrically spaced, which may be termed the sector-charging collectors. These are preferably mounted on a stationary plate, so as to keep the sector-chargers c c entirely insulated from the surrounding portions of the machine. These sector-chargers are connected electrically with the sectors or static inductors of the machine, which sectors or static inductors are mounted on stationary plates of insulating material placed opposite the revolving-plates. The sectorcarrying plate for the revolving plate 1 is shown in the plane or position 1 adjacent to plate 1 in Figs. 1 and 2. The sector-carrying plates clear the shaft of the machine and may be made in sections, though I prefer to have them entire, as shown. They may be made of glass or hard rubber, as usual, and on the side of the plate 1 away from plate 1 is mounted a pair of sectors s s, (seen in dotted lines in Fig. 2,) cmbracing the area from one set of collectors or combs to the other. These are made in' the usual way by pasting shellacked paper against the side of the plate 1, allowing a space around them for insuring insulation. They may also be made partly or entirely of tin-foil, a wire or metallic connection being made to the sector-charging combs c. The latter may in fact be mounted upon rods 7' r, insulated by being carried in the sector-carryin g plates themselves and connected to the sectors of the machine from the rods '7' r. In like manner a similar plate '7 is inserted between revolving plates 2 and 3, another, 8, between the plates at and 5, while the sets of collectors with their rows of points are placed opposite the sectors on the other sides of the revolving plate. hese are the true collectors of the machine and are in two sets, as shown at fff. They are carried on rods T T, Fig. 2, running through the sector carrying and insulating plates 1, 7, and S and ending in the insulated terminals T T of the machine, one of which at any time will be positive and. the other negative. One of the set of revolving plates is the eXciter-plate or" the machine, and carries upon its surface either tin-foil patches or buttons Z) b of metal. These correspond to the usual carriers of the plates of the Toepler-lloltz machine. The other plates are as in Fig. 3, having collectors ffopposite one face and the sectors .9 .9, carried on an insulating-plate 7, 011 the other side, the sectors being connected to the rods 0' 7' and seetoncharging collectors c 0. Both the sets of combs or collectors e e and sector-chargers c c are provided with light metallic brushes, which are made of tin-foil or wire and touch the carriers or buttons 1) Z) as they pass during the revolution of the plate 1. The direction of revolution is as shown in Fig. 2 by the arrow. It is well known that in such a structure as Fig. 2, which is in reality a singleplate Toepler-lloltz machine with the prime conductors or collectors left oft, the slightest difference of potential existing between any two buttons or carriers 1) l) or portions of the revolving plate will, on the revolution of such plate, cause a charge to be produced in the sectors or upon the sector-surfaces s s by inductive actions of an accumulative nature, and that this effect is enhanced by the presence of the equalizer c e, the result being that the parts shown in Fig. 2 would give rise to a high electric charge of opposite name in the two sectors .9 s. It is unnecessary to go into the theory of the actions, except to say that a button or carrier 1), arriving at a contact position with the sectoreharger c, would,by the light metallic brushes carried on the latler, communicate its slight charge to the corresponding sector s, which, diffusing from the sector .9, would act inductively on the revolving plate opposite the equalizer and force off through the equalizer or button which was near or in contact a like charge, thus leaving the plate slightly charged with opposite polarity, as well as the button I) leaving the equalizer. This button arriving at the opposite sector charged with opposite polarity and making contact therewith causes a like distribution of opposite polarity in the opposite sector,which again acting inductively through the equalizer teeth or comb corresponding to it forces ot'l' electricity of like name, which neutralizes that given to the other end of the equalizer and leaves the plate or the carriers thereon more strongly electrified on again arriving at the first named sector charger. This enhances the difference of charge and again multiplies itself with each revolution of the plate until the whole plate and the points of the collectors take part in the process by virtue of a sufliciently high potential having been accumulated in the sectors. I leave out any collectors between the sector-chargers and the equalizers, since it is not desired to make the plate 1 contribute any part of the output of the machine, but merely to cause it to work in the most effective way as a sector-charging disk or exciter for the rest of the machine. lly connecting the other sectors of the machine exciting a battery of plates (which may be a considerable number and may be represented by plates 2, 3, 4, and 5) to the sector-charger a c in the same way that the sectors on the plate 1 are connected a static inductional field is provided for each revolving plate and sustained by the exciting-plate 1, but opposite the sectors which are thus charged and which act on the re volving plates 2, 3, 1, and 5 are found the main collectors fff, positive and negative, respectively, on opposite sides of the machine, and which when the plates revolve take up from such plates under the inductive inlluence of the charged sectors on the stationary insulating-plates charges which are communicated to the terminals T T of the apparatus. Since the polarities of the sectors are maintained positive and negative, respectively, the collectors take up positive and negative charges and charge the terminals, so that the output of the machine depends upon the number and capacity of the revolving plates provided with collectors, while the electromotive force or potential of the machine depends upon the perfection of the insulation of the sectors throughout and to the effectiveness of the exciter-plate l in setting up a high difference of potential between the sectors of opposite polarity. Since the sectors s s, Fig. 3, which act upon the working plates 2, 3, 4, and 5 of the machine have only to act upon the collectors, they may be made to cover but a small angle around the axis, as shown in dotted lines, Fig. 3, and in consequence of this fact it is easily possible to multiply the number of sectors around the axis and the collectors which correspond to them, so as to increase the output of the machine in proportion to the number of sectors around the axis. Thus in Fig. at the sectors are doubled in number, and those of like polarity are at opposite ends of a diameter, while the sectors at right angles to them are of opposite polarity. In such case the collectors are grouped in the same way-that is, the two opposite collectors horizontal in the figure are of the same polarity and attached to a terminal of the machine, while the vertical ones are of the opposite polarity and are connected together and to the other terminal. The i11- duetive charges during the revolution of the plates are thus multiplied by two and the out put of the apparatus doubled.

The advantage of the improvement described is manifest. It permits the charge in the sectors which act upon the working collectors to be maintained without reference to the condition of closed or open circuit between the terminals of the machine, while the exciting end or portion of the machine, not having any working collectors, the excitation thereby given cannot respond to conditions of the working circuit. The apparatus is therefore not so liable to reversal as other forms of machines in which the working 001- lectors are used throughout. At the same time, since the sector-charging operation is performed for the whole machine by the electrical activity of only a part thereof which is reserved for excitation, the work obtainable from the revolving plates is increased and the insulation of the parts improved. In the case of glass it is of course preferred to varnish it.

For dividing and separating the excitcr portion of the machine more effectually from the working portion, especially from the working conductors, a septum or diaphragm D of in sulating material is employed, mounted, preferably, between that portion which is the ex citing portion and the working portion of the machine, Fig. 1. If the distance between these portions be increased, the diaphragm D might be left out; and, in fact, there is no limitation in my invention to the placing of the exciting portion on the same shaft with the generating or working portion, as they could be run separately and electrically connected and the same result obtained as in the construction shown. It is to be understood also that wherever insulating material is needed to thoroughly separate the portions of the ma chine which are to be maintained at high differences of potential it is provided in the usual way by rubber pillars, bushings, or the like.

In the modified form of my invention shown in Figs. 5 and 6 I employ for the exciting porion of the machine a complete lVimshurst machine, one of the plates of which is mounted on the main shaft, carried between the bearings B B, as before, and the other plate, revolved by a pulley p in the opposite direction to the other plate of the machine, is carried on a rotating sleeve surrou nding the said shaft. The usual crossed equalizers are opposite the plate, and there are tin-foil surfaces on the plates, with metallic brushes on the equalizer, making contact, as more clearly seen in Fig. 5. In this case the main collectors c c of the machine are retained, but are not connected with the workin g circuit or terminals of the machine. These collectors are connected only to the sectors of the plates 7 and 8 and take the place of the sector-chargers c c of Figs. 1 and 2. It is not necessary to describe in detail the lVimshurst machine, as this is well known in the art. My invention utilizes this construction as a sec tor exciter, exciting the main machine solely by connecting to its terminals 0 e sectors to be charged and kept charged, which provide the static inductive field for the rest of the machine, which may include as many revolving plates and sectors as desired. It is well known that the Wimshurst type of static machine works best and reaches its highest excitation when it is arranged with its terminals disconnected, or on open circuit. Hence itis well adapted to sustain the charges on the sectors, they being insulated and contributing only a static field effect. The construc tion may have two or a larger number of sectors, like those shown in Figs. 3 and 4:, on the working part of the machine, its construction being identical with that shown in the prior figures.

It has been usual hitherto to construct the collectors of static machines with rows of points projecting toward the revolving plates. These points being sharp are very apt in case of slight displacement of the plates to rub on them, blunting the points, at the same time scratching the surfaces of the revolving plates and in some caseslessening the safety of the machine. 1 depart from this construction radically by making the collectors so that the points are turned in the direc- IIO tion of revolution of the plates and located nearly in the same plane. This detracts in no way from their effectiveness as collectors, but prevents the possibility of contact and consequent damage. Thus in Figs. 7 and 8 the construction of the collector sectorchargers c c, Fig. 2, and the equalizer-combs e c is shown. A bar of metal or wood (seen in side elevation in Fig. 7 and in plan in Fig. 8) is provided with aset of pins or metal points projecting therefrom in the direction of revolution of the plate adjacent to which the collector is supported. If the support be, made of wood it suffices to insert ordinary pins through it and connect the pins at any point,as under the heads, by a fine wire,which is led along a groove in the top of the piece and brought into connection with a metallic rod upon which the perforated end is placed. The connecting-wire is marked it. Many variations from this construction are of course possible, the chief object of which is cheapness and freedom from the disadvantages of scratching and injury just pointed out.

lVhere the collectors are to act as contactmakers for the buttons or carriers 1) h, Fig. 2, they are provided in addition with a light metallic brush M, which is directed toward the revolving plate and touches the metallic surfaces carried as they pass. The brush M is also connected electrically with the rest of the collector.

For the main working collectors of my machine the simple construction of Figs. 9 and 10 is SlllIlClGlll]. Here the row of points is as before, but without a brush, since they simply act as static collectors and not contactmakers, and, as before, the points are turned in the direction of revolution and at a slight distance from the revolving plate, the position of which is shown in dotted lines in the lower part of Fig. 10. By arranging the collector-points, as I have shown, in planes parallel to those of the revolving plates another advantage is secured in that a single collector inserted between two revolving plates serves equally for both, and at the same time on account of its flatness the two revolving plates so served may be brought very close together, and far closer than could be the case in other constructions.

I find it an advantage to provide means for quickly reversing the connections of a static machine when it is used on work (such as exciting a Crookes tube) where the polarity must be maintained in a single direction or where, after connection has been made, it is desirable to reverse the connections without disturbin g anything other than the properly-provided movable portions of the apparatus. I also find it desirable to be able to make this change of connections and at the same time adjust the sparking-distance or sparlcgap, as it is sometimes called, between the terminals of the work-circuit external to the machine. This is particularly the case when Leyden jars are used as condensers on the terminals. I also find it desirable to be able in the operation of the machine to provide the case inclosing it with an artificial atmosphere without oxygen, so as to obviate the formation of ozone within the case, cxcludin g moisture and preventing loss of insulation and attackby ozone of the various portions of the machine which are corrodible by oxygen. To accomplish these ends,arrangements similar to those shown in Fig. 11 are adopted. At C C are condenser-jars mounted on the terminals of the machine in the ordinary way, whereby a condensenspark is obtained. C011- nections are made to a Crookes tube T by a wire to one terminal, which should be kept the anode, as a, and by another wire Z) to the terminal K, to be kept the cathode. These wires terminate in stationary insulated balls or pillars projecting outwardly from the center of the framework and seen at II II, Fig. 12, one above the other, and spaced apart a suiiicient distance to exceed the total striking distance of the machine. Sliding rods R R, with insulated handles constituting the terminals, may slide toward and from each other in the usual way and are also arranged to swing up and down through an arc of a circle around the pillars P P which constitute the stationary terminals. Assuming that the rods are in the position shown in Fig. 12 in full lines and that the red It is positive, with the red It negative, the positive discharge will be communicated to the insulated ball or piece II and the negative to II through a sparkgap, which may be made as small as desired down to actual contact or as large as possible within the capacity of the machine. This of course is accomplished by sliding the rods in and out toward the stationary balls H H, carried on the insulated pillars I P, suitably supported in turn upon the frame of the machine. If the direction thus given be incorrect for the purposes in view, or if the machine itself reverses its polarity, or if it be desired purposely to reverse the direction of the current through the working circuit including the tube T, and at the same time to adjust the spark-gap to any desired length, all that is necessary to do is to reverse the positions of the rods It R and bring them to the positions shown in Fig. 11 in dotted lines R R when that terminal which was positive and presented to II now is presented to II and the other or negative at the same time to H, reversing or comm utating the connections. This of course can be done without actual contact, and the distance through which the discharge must leap may be adjusted as desired.

I find that a useful addition to the machine is a small stove or furnace, (indicated at F,) connected with a rather long pipe to the interior of the casing of the static machine, Fig. 11, and in which casing openings exist for the escape of displaced or expelled gases, as by a pipe or chimney N in the figure. The furnace F is preferably fed with pure carbon fuel from which moisture and hydrocarbons have been driven. Strongly-carbonized charcoal from hard wood, especiallyif it has been kept dry, and better yet if it has been washed in hydrochloric acid and the acid thoroughly removed, may be used as fuel. The gases leaving such fuel F to pass up in the casing of the machine are chiefly carbonic acid and nitrogen,with scarcely any moisture present. The machine therefore works in this atmosphere with no free oxygen to become ozonized, and is therefore protected from ozone re tained within its inclosing case, while the slight warmth of the gases rising brings the temperature of the machine within the case to a number of degrees higher than that of the atmosphere, in this way raising the dew-point of the contained gases and keeping the machine entirely dry within the casing.

At N in Figs. 1 and 6 I have shown a fine wire of platinum or other suitable material maintained at incandescence by any suitable means, such as a battery or other source of electromotive force 0, the wire acting not only to raise the temperature within the easing, but also to reduce to oxygen any ozone that may be formed therein.

That I claim as new, and desire to secure by Letters Patent of the United States, is

1. In an electrostatic generator, a charging eXciter-plate provided with an equalizer and a pair of sector-charging collectors connected to the sectors of the charging-plate and the sectors of the working plates of the machine, the exciter having no connection with the working circuit.

2. An electrostatic generator comprising a working portion having a number of plates feeding the working circuit, and a separate exciting part having a comparatively small number of plates and corresponding sectorcharging collectors arranged to furnish and maintain a charge for the working part of the machine, the exciting part of the machine having no connection with the working circuit.

3. In an electrostatic generating-machine, collectors having their points turn ed in the direction of revolution of the plates of the machine opposite which they are placed.

4. In an electrostatic generator, a single row of'collector-points mounted between two adjacent revolving plates and turned in the direction of revolution of the plates.

5. In an electrostatic generator, fixed terminals for the working circuit, and a pair of movable terminals so mounted that either movable terminal may approach or recede from either one of the work-circuit terminals, and thus act either to reverse the current, or adjust the spark-gap distance, or both.

6. In an electrostatic generator, a pair of movable terminals mounted for both rotary and reciprocating movement, and a pair of fixed terminals for the working circuit, arranged in a line transverse to that joining the axes of rotation of the movable terminals.

7 An electrostatic generator inclosed in a casing, in combination with means for feeding inert gases to the casing, and therebypreventing the formation of ozone.

8. An electrostatic generator inclosed in a casing, in combination with means for feedin g inert gases to the casing at a temperature above that of the surrounding air, and thereby preventing the formation of ozone and condensation of moisture within the casing.

S). The combination with an electrostatic generator inclosed in a casin g, of a body within the casin g maintained at incandescence and acting to reduce to simple oxygen any ozone that may be formed.

10. The combination with an electrostatic generator inclosed in a casing, of a platinum wire within the casing maintained at incandescence by a suitable source of electromotive force, as described and for the purpose set forth.

In witness whereof I have hereunto set my hand this 31st day of December, 1896.

ELIIIU THOMSON.

Witnesses:

JOHN W. GIBBoNEY, HENRY O. WEsrENoARP.

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