US2831988A - Means for excitation and commutation of electrostatic machines - Google Patents

Description

April 22, 1958 Original Filed Oct. 28', 1954 R. MOREL MEANS FOR EXCITATION AND COMMUTATION OF ELECTROSTATIC MACHINES 3 Sheets-Sheet 1 I I. WM

INVENTOR ROGER MOREL ATTORNEY Apnl 22, 1958 R. MOREL MEANS FOR EXCITATION AND COMMUTATION 0F ELECTROSTATIC MACHINES Original Filed Oct. 28, 1954 3 Sheets-Sheet 2 RADIOACTIVE MATERIAL I INVENTOR ROGER MOREL ATFGRNEY R. MQREL MEANS FOR EXCITATION AND COMMUTATION April 22, 1958 OF ELECTROSTATIC MACHINES Original Filed Oct. 28, 1954 ATTORNEY a United States MEANS FOR EXCITATIQN AND COTATION OF ELECTRUSTATIC MACHINES Roger Morel, Grenoble, France, assignor to Societe Anonyme de Machines Electrostatiques, Grenoble, France, a corporation of France 39 Claims. (Cl. 310-6) This invention relates to electrostatic machines and more especially to electrostatic machines in which a conveyor of the electric chargesis moved between a posi- 7 tion .at which the charges are deposited on the conveyor and a position at which'the charges are removed from the conveyor and delivered to a load terminal. The invention in one/aspect particularly relates to the problem of commutation in such'electrostatic machines, that is, to the transfer of charges to and the removal of charges from the conveyor. In another aspect the invention relates to the problem of excitation of electrostatic generators of the character referred to, which may also involve the problem of commutation.

In machines having conductive conveyors commutation by means of brushes carried by the conveyor or by a member supporting the inductor members and engaging contacts on the other of the two relatively moving parts involves mechanical friction and wear of the brushes and contacts, which result in a certain amount of deleterious dust within the machine. While eliminating the action of friction, as described in the French Patent 1,028,596, commutation through spark gaps maintained between the two relatively moving elements, one connected to the conveyor and the otherto an .electrode of the machine, involves a certain amount of erosion developing dust and roughening of the spark gap elements takes places with spark discharge. Moreover, while machines with conductive conveyors utilizing friction contact may be self-exciting and self-starting, in machines in which commutation is accomplished by means of sparks, self-starting under some conditions may be prevented or may become unreliable.

111 machines having conveyors of insulating material in which the conveyor is moved through a field maintained between an inductor member and an ionizer, no

contacts being made, the charges may be deposited on the conveyor or removed therefrom only upon the development of ions in the space between the ionizer and the insulating conveyor. This ionization may be and conventionally is accomplished by developing and maintaining a predetermineddifierence of potential between the inductor and the ionizer.

This difference of potential may be quite large, of the order of 10 to kV., for example, in certain machines. It requires substantial auxiliary apparatus for the purposes of maintaining an excitation field between the exmay be unduly large relative to the main generator, but

for main electrostatic generators which are of relatively large size such a system of excitation .may be utilized with properbelection of the type of auxiliary exciter generator. When the auxiliaryexciter generator is of the type utilizing a conveyor of insulating material the atent problem arises of initiating its own excitation and the development of ions in the space between its excitation ionizer and its corresponding inductor member.

Such individual generators or assemblies of generators having insulating conveyors are not self-starting unless means are provided for developing ions in the space between the ionizer and the conveyor as above mentioned.- The electric circuit between two generators one of which excites the other ordinarily includes four gaps which can only be bridged according as the ionizers play their part, that is to say, according as they make the ambient dielectric medium, usually a gas, conductive. This functioning of the ionizers may be accomplished if the difference of potential between the ionizer and corresponding inductor member above referred to suificient to initiate the ionization has been developed. In electro-static generators with insulating conveyors the charges built up on the conveyor ordinarily are not maintained for a greatlength of time depending upon the insulation of the conductive parts, the spacing of the conductive parts in the dielectric medium and other conditions. In order to start the excitation, therefore, in an individual generator or in two electrostatic generators connected for excitation of one by the other, it is necessary that the transfer of the ions to the insulating conveyor be initiated by supplementary means to replace the temporarily inactive ionizers.

The present invention has for an important object improvement of the conditions for development of the requisite ionized zones in the ambient gas with respect to the conveyor.

It is a further object of the invention to provide for initial ionization of the ambient gas adjacent the field to be developed between the exciter inductor member for ionizing the ambient gas in an. electrostatic machine permanently or for along period, especially in a machine having an insulating conveyor, in. order to make such'a machine self-starting.

It is anotherimportant object of the invention to provide for initiating and maintaining the excitation of both of two generators one of which may be the exciter of the other.

It is a feature of the invention in one aspect that means are provided for ionizing the space between the ionizing element or ionizer and theconveyor movable between the ionizing element and an inductor member without requiring that the relatively large difference of potential above referred to between the ionizer and the inductor member initially shall be produced to secure excitation of the electrostatic generator. In order to accomplish this purpose in accordance with the invention a body or element of radioactive material is disposed in spaced relation to and adjacent the active surface of the conveyor. Ordinarily this radioactive body or element will be disposed, adjacent the ionizer and in some cases adjacent each ionizer utilized in the electrostatic machine. In

some cases, however, the radioactive body or element i may be substituted for the ionizer and may function with, respect to the inductor member and the conveyor movable between the radioactive body and the inductor member in the same manner as the usual ionizer.

By providing such a radioactive body or element disradioactive body may be provided in a machine without the usual ionizers, which machine would be connectedto the electrostatic generator so as initially to excite this generator and would only serve for starting this generator which, after being started, would be excited by the normal means of producing excitation, for example by an auxiliary exciter generator, or by the operation of two mutually exciting generators as above referred to. t V

In the case of a machine in which reliance for .commu tation is placed upon the permanent ionization by a radioactive body,. all of the usual ionizers being eliminated, it may be preferable to connect across the radioactive body and the usual exciter inductor associated therewith a difference of potential relatively. small with respect to the excitation potential. .Such. small potential difference may be of the degree of to 500 volts. This potential will act to resist the recombination of the ions above referred to as well as to control the polarity of the machine by controlling the polarity of the ions conducted across the ionized space to'the conveyor. Such a potential may be supplied by a battery or by means producing a rectified potential from an alternating potential or it may be supplied by an electrostatic friction generator.

In the case of mutually exciting generators as above referred to, if the electric charges capable of being conveyed by virtue of the radioactive rays andthen by virtue of an auxiliary field developed between an inductor member and an ionizer are sufiicient and greater than the charges lost in the machine during starting by leakage in the insulating materials by corona discharge or in the i load circuit, a diiference of potential will develop and will increase until the usual ionizers take over the operation and the permanent conditionsof operation for which the machine is designed are established. The conduction across the ambient space secured by the radioactive body then is no longer necessary and may be negligible with respect to the conduction developed due to the ionization of the gas by the electric field established between the inductor member and the ionizer under the potential difference maintained therebetween.

In the second aspect of the invention two generators, each provided with an insulating conveyor, which are required to excite each other, may be separate or they may be grouped together in accordance with constructions hereinafter referred to, but each of these conveyors preferably are provided with at least two ionizers, that is, one charging ionizer and one discharge ionizer. One of the generators generates positive charges and the other negative charges. These two generatorsand the equivalent construction which utilizes a single conveyor with which the four ionizers and the associated inductor members cooperate constitute a 4-pole assembly or machine. If the assembly or machine comprises more than 4 poles, in principle it would still be sufi'icient to provide a total of two charging bodies of radioactive material and two discharge bodies of radioactive material cooperating with the respective ionizers.

The radioactive material advantageously may be deposited on a thin blade or plate which may be electrically connected to the adjacent ionizer and this blade and the radioactive material carried thereby both may be enclosed in an envelope for the purpose of avoiding detachment and dispersion .of the radioactive material and to facilitate handling of the thusassembledbody. .The envelope may be of metal or may be of a plastic or other provided for purposes of the invention is' a function of. the desired speed of development of the self-starting action. Such amount also is dependent upon the conditions ofthe insulation of the machine, of the electrical capacitance of its members and, in the case where the radioactive sourceis intended to provide commutation permanently or over a long period, it is dependent upon the desired amount of charge to be delivered to the load circuit. The electric charges conveyed through the machine have a tendency to disappear according as the potentials increase where the insulation is not perfect, thus interfering with the starting. The production of high potentials, therefore, requires somewhat larger amounts of radioactive material than for lower potentials.

The radioactive value of 'the radioactive body may be generally between and 1000 micro-curies. If, as in the case with polonium, the period is relatively short, such an amount of radioactive material must be provided so that its efficiency after a certain time remains sufiicient to secure ionization of the space'adjacent the radioactive body and between this body and the conveyor. By suitably determining the amount of the radioactive material having regard to its half life, periodic'replacement of the radioactive body may provide a practical means for substantially continuous effective self-starting of the electrostatic machine.

In view of the hazard as well as the cost involved in the use of radioactive materials, it is necessary to operate with a-minimum of material for the radioactive body and the question of insulation becomes paramount.

The presence of humidity in the gaseous space is, therethe risks of ingestion and inhalation, in industrial plants handling these materials for manufacture of the electrostatic machines, the necessary precautions for safety may be taken without difficulty.

The objects and features of the invention above referred to and others will be further understood from/the description to follow of several embodiments of the invention. It is to be understood that the invention is not intended tobe limited to these embodiments either as to the methods of carrying out the invention or as to the particular constructions and arrangements shown in the drawings in which- Fig. l is a schematic section taken transversely of the axes of rotation of two electrostatic generators having rotatable conveyors of insulating material, these generators being mutually exciting and being started by radioactivity.

Fig. 2 is a longitudinal section of a single conveyor of insulating material associated with the ionizers and with the common inductor members of two electrostatic generators utilizing radioactive elements for starting.

Fig. 3 is a schematic transverse section of two electrostatic generators utilizing a single rotatable conveyor of insulating material rotatable in succession into the ionizing zones provided by the radioactive elements of the two generators.

Fig. 4 is a schematic transverse section of an electrostatic machine in which commutation is permanently secured by radioactive bodies without utilizing'the usual ionizers.

Fig. 5 is a schematic transverse section similar to that of Fig. 4 in which the radioactive body associated with the discharge terminal is replaced by a conductive brush.

Figs. 6 and 7 respectively are transverse sections showing, by way of example, dispositions of'the radioactive body or element in relation to the usual ionizer.

Fig. 8 is a longitudinal section of a blade provided porting member.

Fig. 9 is a schematic section of an electrostatic generator having conductive conveyors and utilizing radio-v active elements for starting. 1

Fig; 10 shows diagrammatically two mutually exciting generators utilizing conveyors of insulating material and provided with conventional ionizers without associated radioactive elements.

In Fig. 1 generator 1 is provided with a continuous cylindrical conveyor 3 of insulating material rotatable on the axis of the cylinder. Within the cylinder 3 is disposed the usual ionizer 5 connected to ground. This ionizer in this embodiment is a thin blade set edgewise to the surface of the conveyor and extending lengthwise along the surface of the conveyor. Also within the cylinder .3 and connected to ground is disposed a radioactive body or element 7. Opposite to the ionizer 5 and the radioactive body 7, which are disposed adjacent to each other and electrically connected together in this embodiment, is disposed an exciter inductor member 9 which, for purposes of explanation, is assumed initially to be at a plus potential.

The inductor member 9 when brought to a suitable potential acts to develop an electric field with respect to the ionizer 5, develops a field in the space between the insulating cylinder 3 and the ionizer 5 and negative ions are conducted across this space and are deposited upon the inner surface of conveyor 3. This action may occur when the field developed between the inductor member 9 and the ionizer 5 becomes of sufiicient strength. In order, however, to start the movement of ions across the space between the ionizer 5 and the conveyor when the potential of the inductor 9 is insufficient, the radioher'einabove described. Upon rotation of the cylinder 3 in the direction of-the arrow in Fig. 1, the negative ions are carried on the inner surface of the cylinder 3 to the position adjacent the discharge electrodes of the electrostatic generator 1.

These discharge electrodes in the embodiment of Fig. 1 comprise an ionizer 11 with which is associated a radioactive element 13 electrically connected to the ionizer 11, this ionizer and radioactive element being disposed adjacent the inner surface of cylinder 3 so that the negative ions carried upon this inner surface are collected by the ionizer, the space between the ionizer and the inner surface of the insulating cylinder 3 initially being made conductive by virtue of the radioactive element 13.

Because of the build-up of the potential of the charges carried on the inner surface of the cylinder 3 in its rotation from the position adjacent theionizer 5 to position adjacent ionizer 11, these charges are transferred across the conductive space to the ionizer 11 which, as shown in Fig. 1, is connected to the discharge terminal 15 of the generator 1 in the embodiment of Fig. 1. Screen inductor member 17 also is disposed at the opposite side of the conveyor from the ionizer 11 and is connected thereto so as to be maintained at the discharge potential of the generator at the terminal 15. This screen cooperates with the ionizer 11 in the same manner as the screen disclosed in the French Patent 1,051,430, January 15, l954,in the discharge of the charges collected by the ionizer 11 to th load terminal 15.

It will be understood in accordance with the inventive concept, as set forth hereinabove, that the radioactive bodies or elements 7, 13 initially provide for the move ment of ions between the radioactive elements and the wall of the conveyor 3 to make the space between the usual ionizing elements 5, 11 and the conveyor conductive. lVhen by suitable means the exciter inductor 9 is brought to a predetermined potential andthe full electric field between this inductor member and the ionizer 5 is produced, then the machine may act as a generator in the normal manner and the charges carried by the-conveyor delivered to terminal 15. When such a normal operating condition is secured, the function of the radioactive elements 7, 13 has been accomplished and the ionizers 5,111 may take over the function of maintaining the, ionization of the space between these ionizers and the surface of the conveyor. It, therefore, would be possible to remove the radioactive bodies 7, 13, or otherwise to make them inactive by any suitable means. As a practical matter, however, depending upon the conditions under which the machine operates, these radioactive bodies may remain in place and continue to function in parallel with the respective ionizers 5 and 11.

The potential necessary to be provided on the inductor member 9 for normal excitation may be small relative to the potential to be developed at the terminal 15 of the generator but must be high enough to develop an intense field at the ionizer 5. With the arrangement shown in Fig. 1, however, the amount of current which it is necessary to supply to the inductor member 9 is negligible, the amount of charge delivered to the terminal 15 being determined by the field and the build-up of the potential as the result of the rotation of the cylinder 3. The amount of charge necessary to be supplied by the emission of ions between radioactive elements 7, 13 and the conveyor 3 may be relatively small, as generally explained above, initially to secure the conductivity of the space between the ionizers S, 11 and the inner surface of the conveyor 3:. I

When, as about to be explained, the load terminal 15 in Fig. 1 attains sufiicient negative potential, the exciter inductor member 19 of the generator 21 which is connected to the terminal 15 of the generator 1 is excited correspondingly at this negative potential. This exciter member 19 develops with respect to the ionizer 23 of the generator 21 an electric field, this ionizer 23 being connected to ground as well as to the associated radioactive element 25. The inductor member 19, the ionizer 23 and the radioactive element 25 function in the same manner as the inductor member 9, the ionizer 5 and the radioactive element 7 of the generator 1 to ionize the space between the ionizer 23 and the inner surface of the cylinder 27 of the generator 21, so as to deposit positive ions on this inner surface which are conveyed thereby in the rotation of the cylinder 27 in the direction of the arrow. These positive charges thus conveyed are delivered to the ionizer 29 connected to the load terminal 31 of the generator 21.

The radioactive element 33 cooperates with the ionizer 29 initially to make conductive space between the ionizer 29 and the conveyor 27 in the same manner as the radioactive element 13 of the generator 1. The screen inductor 35 functions similarly to screen 17 of generator 1. Thus, a plus potential is built up at the terminal 31 and when this potential becomes suflicient it serves for excitation of the inductor member 9 which, as shown in Fig. 1, is connected with the terminal 31. As above indicated the amount of the charge required to be delivered to the inductor member 9 by the generator 21 as well as the potential required to be generated at the terminal 31 for charging the inductor member 9 may be merely sufficient to secure the excitation in the generator 1 for developing the requisite high potential at the terminal 15 r of this generator.

It will be understood, however, with respect to the inductor member 19 that initially the negative potential supplied by the generator 1 to inductor member 19 may be insufficient to bring into normal action the ionizer 23. As the potential developed at terminal 15 and supplied to the inductor 19, however, increases, the radioactive element 25 meanwhile supplies positive ions which are deposited on the inner surface of the rotatable conveyor 27. These charges are carried by the conveyor 27 and are delivered to the ionizer 29 even though the potential of the charges with respect to the inductor member 35 maybe insufficient to discharge these charges across the space between the conveyor 27 andthe ionizer:29 because the potential of the inductormember 35 is not yet suflicient. The radioactiveelement 33, however, supplies. sutficient ions to provide the, requisite conductivity of the space so that the charges carried on the conveyor 27 may be delivered to the terminal 31 and ally reinforce each other until the ionizers take overtheir ordinary functions.-

In Fig. 2is shown in longitudinal section a rotor 40 of H section "having aqcentrally disposed web 41 which may be provided with a bore 42 for mounting on the shaft of an electrostatic generating machine comprising twoelectrostatic generators which may be connected electrically for mutual excitation similarly to the arrangement described in connection with. Fig. 1. -In the embodiment of Fig. 2 the inductorfmember 43 at plus potential takes the place of both the inductor members 9 and 35 of Fig. l and exten'dsgenerally parallel to the axis of the rotor 40 in spaced relation to the circumferential surface of the rotor and parallel ther'eto. Similarly the inductor member 45 takes the place of the inductormembers 17and 19 of Fig. land is disposed in spaced rela-'-- tion to the circumferential surface. f 10t0 1fi4 0 and paral-' lel to its axis. e

In the embodiment of Fig. 2 the blade 41 disposed in edgewise relation. to the inner surfaceiof'the rotor 40 at the left-hand'portion of "this rotor and opposite to 2 enemas l0 ment or these blades may be made radioactive by any other suitable construction as hereinabove suggested.

It will be understood from the description just given and by comparison with Fig. 1: that the circuit arrangement shown in Fig. 1 which connects the output or screen inductonmember 17 and the associated ionizer 11 to the exciter inductor member 19 associated with the input or charge ionizer 23 and which connects also the output or screen inductor and its associated ionizer 2? to the exciter inductor member-9 associated with the input or charge ionizer 5 is carried out in the embodiment of Fig. 2. The connection between the inductor members 17, 19 of Fig. 1 is provided by the continuous inductor member 45 of Fig; 2. The connection between the inductor members 35, 9 of Fig. 1 is provided by the continuous inductor member 43 of Fig. 2. The connections of the input or charge ionizers 5, 23 to ground correspond with the connections of the ionizers 4'7, 53 to ground in Fig. 2.

have a form as disclosed in the co-pending application of Roger Morel, Serial No. 492,494, filed March 7, 1955, the two conveyors being disposed at opposite ends of the shaft of the motor so as to berotatable on'a common axis with the m0tO1'. I

Adjacent the outer surface of the conveyor 101 two exciter inductors "105'are disposed at opposite ends of the the. inductor member 43f takes theplace of both the i ionizer 5 and the radioactive element 7 of Fig. 1. 'The Y blade 47 may be made radioactive by suitable means, I

such .as those described hereinabove. Ifdesired, one

part of the length of this blade 47, for example the p i may be coni'i'pport radio- 49. constituting left-hand portion 48, as shown in Fig. '2 stituted by radioactive material or. ma active material, 1 the right-hand. portion theusual ionizing element. H

. Similarly the blades 51 in FigLZdisposed opposite to the inductor member 45,1na y "comprisejtwo portionscor responding to the ionizer 1'1. and"tl1e' radioactive element 13 of Fig. 1. As-shown in Fig." Zthe blade 51 maybe electrically. connected with the inductor imernber 45.1 It will be understood that byyirtue of the 'continuousextent of the inductor memben-td over the length of the rotor diameter and are electrically connected together. At the opposite side of the conveyor wall from the inductors 105 exciter ionizers 1117 are disposed that are electrically connected together and, 'if desired, may be connected to ground. Disposed in circumferentially spaced relation about the axis from the inductors 165 and adjacent the outer surface of the conveyor 101, screen inductor members 109 are disposed that are electrically connected togetherandare connected to the. respective collector ionizers 111 that are disposed at the opposite side of the conveyor wall from the screen inductors 10 in opposed relation thereto."'. It. will be understood. that the fields developed between the exciter-inductor members 105 and tors 109.

40, the right-hand portibnfof this inductor member may i function as does the inductor member vf1!) .of Fig.- l.

Similarly the blade53 disposed adjaeent thejnner surface of the rotor 40 at the right handjpoifltion thereofcooperates with the inductor member;45;as do,the iomzer 23 and the radioactive eIementQZS in Fig. 1 withithe 'inductor member 19, the blade 53. being connected to ground. Charges delivered to theinner surface of the Y the respectiveionizers 107 may produce ions to be carried on the inner. surfaceiof the conveyor 101 and collectedby the respective collector ionizers 111. These charges may be delivered to the respective screen induc- Thecharges alsoare delivered through the connection 112 to the exciter inductors 113 of the machine at the right hand of Fig. 10, these exciter inductors 113 being disposed at the ends" of diameter: and adjacent the outer surface of the conveyor M3; ionizers 115 are disposed at the inner surface of the conveyor 103 in opposed relarotor 40 at this right hand portion areiconveyed thereby and discharged to the blade 55disposed "adjacent the inner surface of the rotor opposite ;.to the right -.hand. portion of the inductor member 43,- the-.bladef5 5jbeing electrically'connected to the inductor fmemberaifi The tion to inductors 113 and arei electrically connected to- 'getherand may be connected to ground. In circumferenj'tiallyspaced relation to'the inductor members 113 screen 'induc'tor members 117 are supported adjacent the outer surface of conveyor 103. Charges developed on the inner surface of the conveyor 193' are collected by collector blade 55 thus-functions as do the'ioniz'er'29 andlthe radio-f active element'33 of Fig. 1 .with respect-to then'nductor member 35. The left handportion of' the condudtitteinductor member 43 'beingiielectrically fconnecteds to the right hand portion thereof functions as does the inductor member 9 of Fig. 1. i

51 53, 55 may be formedwithgtwo 'part s, onepattb'ing}. the usual ionizer and the other pjarttheradioactive eleionizers 119 that areconnected to the. respective screen inductor members 117 and'are delivered to these screen inductor members and are also delivered through the conductor 121 to the exciterinductor members of the machine at the left ofFig- 10. l

Thus, it will beunderstood thatthe machine at the left in 'Fig 10 ;serves to excite the right hand machine and I, l o I, 1;. ;that the machine attheright'inFig. 10 serves to excite As described in connection with blade47, the blades the. lefthandlmachine'. As shown in Fig. 10, the two col- "lector ionizers 111 and the corresponding screen inductor i I may be connected through the conductor 123 to the output terminal 127 and the two collector ionizers 119 in screen inductor members 117 connected thereto may be connected through inductor 125 to outputterminal 129 if itis desiredjto use the charges in an outside circuit.

The arrangement. and interconnections between the electrostatic machines shown in Figs. 1, 2 and are typical of how two machineswhich, for example, may be driven by a common motor maybe operated for mutual excitation in accordance with the second aspect of the inven tion'. It will be understood that in two electrostatic generators thus connected for mutual excitation, if desired, radioactive bodies may be'utilized in the manner hereinabove described for facilitating the initial development of ions in the dielectric medium or ambient gas in which the conveyors and ionizers operate, or other starting means may be used. I

In Fig. 3 is shown in transverse section a combined set 60 of two electrostatic generators in which the induotcr members are disposed in spaced relation circumferentially about the axis of a single cylindrical conveyor of insulated material rotatable on its axis. In the embodiment of Fig. 3 the inductor member 61- is intended to be maintained at plus potential similarly to the inductor member 9 of Fig. 1. The cylindrical conveyor 63 rotates in the direction of the arrow and conveys negative charges delivered thereon from the ionizer 65 connected to ground to the position at which these charges may be delivered to the ionizer 67 connected to the inductor member 69. By suitable means the ionizer 65 is made radioactive and ions may be conducted across the space between the ionizer 65 and the inner surface of the conveyor 63. These negative charges similarly may be conducted. across the space from ,conveyor 63 to the ionizer 67 which also is made radioactive by suitable means. If the charges developed and conducted across the ambient spacesunder the action of the radioactive ionizers 65, to are greater than those lost due to leakage, the potential of the charges will increase and the potential also of the ionizer 67 and of the inductor member 69 will be increased. I

The ionizer 67 and the inductor member 69 are connected to terminal 71 at negative potential and this terminal is connected with "the inductor member 73 disposed opposite the ionizer 75.v Thus, positive charges may be deposited upon the inner surfaceof the conveyor 63 at the radioactive ionizer 75 and in therotaticn of the conveyor in the direction of the arrow they are conveyedto the position adjacent the radioactive collector.

ionizer 77. This ionizer 77 is connected tothe screen inductor member 79 and to the terminal 31 which also is connected to the inductor member 61.

assnoss initially are deposited by virtue of the function of the radioactive'materialcarried by the ionizers to make con-v ductiv'e the spaces between these ionizers and the inner surface of the conveyor. 1

In Fig. 4is shown an arrangement for determining and maintaining the polarity of an electrostatic machine utilizing radioactive elements for initiating the excitationof the machine and the conveying of charges to the conveyor. This means also functions to prevent recombina ticns of the ions produced by'the radioactive materialof these elements. In Fig. 4 the combined ionizer andradioactive element 85 is connected to :groundand is disposed. adjacent the inner surface of the cylindrical conveyor 37 of insulating material and at the opposite sideof this conveyor: from the exciter inductor member 89. A source of electrical potential, such as a battery 90, may be connected between ground, and the inductor member $9 to determine and maintain the potential, of member 89 and the polarity of the machine. The charges deposited on the conveyor by the radioactive element 85 are carried on the inner's'urface of the conveyor rotating for .example, in the direction of the arrow and are delivered to the radioactive ionizing element 91 electrically connected to the screen electrode 93 and connected to the output terminal 95 of the machine. Because of the continuous action of the radioactive material of the elements 85 and 91, the commutation of the machine is assurcd with a predeterminedpolarity and recombination of the ions produced bythe radioactive material at the same time substantially is prevented.

Theamount of charge which may be delivered to the:

c'asiesit may be advantageousto provide a regulating tie-- vice, such as a corona'regulator or aspark discharge,

which will make possible the absorption of charges that are not utilized. v i Increase of the potential applied to the {exciter inductor 89' increases the amount of charge delivered at the load terminal 95': A point is rapidly reached, however, where all of the'char'geslwhich are developed by the radioactive element are carried by the conveyor and The ionizers 75 and 77 are made radioactive by any 1 suitable means and charges, therefore, may be conducted across the space between these ionizers and the inner surface of the conveyor 63, so that these. charges .at positive potential are delivered to inductor'mernber '79, the terminal 81 and theinductor member 61. The two'- sections of the electrostatic machine of Fig. .3, therefore, constitute two generators which are interconnected so that the potentials of the inductor. members and'the" corresponding ionizers gradually are builtup and each generator excites the other. by virtue of the radioactive character of the ionizers which, when the desired potentials are. attained, then function in the normal manner as ionizers.

It will be understood that the machine of Fig. 3 uti lizes the rotatable cylindrical conveyor 63 alternately to carry negative charges and positive charges on the same surface of the conveyor. In the movement between the l in . spaced relation to-the inner surface thereof. The radio- Such excitation isinitiated saturationo f charges thereon occurs.

t Within thescopefoftheinvention as shown in Fig. 5 the combined ionizer and radioactive element 91 of Fig. 4 may be'replaced by a collector brush 97 rubbing on the innerjsurfaee of the conveyor 87 for collecting the charges conveyed by the conveyor 87 and delivering them'to the load terminal 95 and to the inductor 93 similarly to Fig. 4. I

Fig. 6 shows" ;atransverse section of a portion of a cylindricalfconveycr 103 rotatable on thc'axis of the cylinder between. inductor MS, as in Fig. 1, and both an ionizer1 1G7 and a 'radioactive element 169. In the embodiment ofFig. 6'theionizer N57 is provided by a wire stretched parallel to the axis of the cylinder in active element Hi9 which is generally rectangular in section in "6has its length parallel to the axis of the cylinder and inspaced'relation'inwardly with respect The ionizer in? and the radioactive element Th9 are supported by suitable means, not showinfonan insulating'stator member 11.1. It will be'undferstood that {the action of the radioactive element ionizer 65 and the ionizer 67 negative charges are carried by the conveyor and delivered to the terminal 71. In P the movement between theionizer and the ionizer 77' positive charges are conveyed and delivered tothe'terf I minal 81. In each section of the machine the charges initiating conductivity of the space between the ionizer and the inner surface of titer-conveyor M23 may take place, asabove described'in connection with Fig. 1, "for exarnple and that thereafter the ionizer 107 may take over and maintain ionization of the space 'so that the ch'arges may pass across the sp'acc between this ionizer and 1' the circumference of the conveyor, the inductor member-105 cooperating with the ionizer 107 to provide the electric field:

In the embodiment of Fig. 6 a shield 113 is provided which may be supported by the stator111. This shield its length parallel to the cylinderof the rotor 103 and beneath and extending about the radioactive element 109. This shield, as shown in Fig. 6, may havethe edges of the channel rounded toavoid concentration of the elec: tric field, thereon. The channelmay be of such material aswillabsorb and arrest radiations from theradioactive element-109which are directed toward the stator 111 and which may attack the insulating material of this stator. tive spaces within the generator, including spaces .occupied by the gaseous dielectric material in which the electrostatic generator operates, which spaces must not be conductive but which must retain their dielectric characteristics. Preferably the ionizer 107and the radioactive element 109 are connected together and are connected to the shield 113 so as to be in the same potential.

' In Fig. 7 is shown a modification of the arrangement of the ionizer and of the radioactive element generally described in connection with Fig. l in which the ionizer 115 is provided by a blade supported on its edge 1 on the insulating stator 111 in a groove 116 formed at .the periphery of this stator parallel to, the axis of the insulatingconveyor 1113, the blade 115 being set edgewise also to the inner surface of the conveyor 103. Also in the groove 116 formed in the stator 111 is disposed the radioactive element 117 which may be supported on the bottom of the groove and extending parallel to the blade 115 throughout such part of the length of this blade and of the inductor member 119 as will provide the requisite conductivity of the space adjacent the ionizer 115 to initiatethe charges onthe inner surface of the conveyor 103 as above described.

Fig. 8 shows somewhat diagrammatically a plate or ,blade 121 which is embedded at its edges in a supporting member 123 of insulating material and bears on this member adjacent a window 125 formed in the member 123. At the upper surface 127 of plate 121 radioactive .material is applied as a coating or in other suitable manner to secure the ionization of the space adjacent thejplate 121. The assembly of the plate made radioactive as described and the supporting member 123 may be'disposed in proper relation to the active surface of an insulating conveyor in the position, for example, of the element 117 of Fig. 7. I

Within the scope of the invention of conductive material. Such an electrostatic generator is shown by way of example in Fig. 9 and may comprise an exciter inductor member 131 intended to be; maintained" at a positive potential, for example. Upon a conductive conveyor 135 when in face to face relation to the inductormember '131 negative charges will tend to be induced and these charges may be supplied-from ground through an ionizing element 137 when the space between this ionizing element 1 and the conveyor 135,

ative charges upon the conveyor 135 rotating inthe direction of the-arrow about. the axis ofthe cylindrical inductor and conveyor members are carried to the posi-.

The space between doubt the collector ionizer 141. this ionizer 141 and the conductive member electrically connected to the conveyor 135 moved to the position of conveyor- 143 of Fig. 9 is ionized and. made conductive by the radioactive element 14-5. The negative charges 1 thus collected by the ionizer 141 are delivered to the These radiations also might make conduci may be in the form of a shallow channel disposed with load terminal 147 as well as to the screen inductor 149.

Correspoudingly the conveyor 143 during the movement of the conveyor135, having been moved from the position shown in face to face relation to the inductor 149 to the position in face to face relation? to the inductor 131, also will become charged with negative charges conducted thereto across the space between the ionizer'137 and the conveyor 143, this space being made conductive by the radio-active element 139. The conveyor 143 upon further rotation will carry these charges to the position of the conveyor 143 in Fig. 9 and deliver them to the load terminal 147 through the ionized space between the ionizer 141 and the conveyor 143 as above described for the conveyor 135. In both positions'of the conveyors the radioactive elements 139 and 145 respectively develop conductivity of the ambient gas spaces for flow of the ions and the charges across the spaces to carry out the functions which have been described.

The invention is not limited to the particular embodiments described and disclosed in connection with the drawings and may utilize conveyors and inductor members as well as ionizers and radioactive elements of various forms while providing the function afforded by the radioactive material associated with a conventional ionizer or functioning as an ionizer itself to secure conductivity of the space and particularly of the ambient gas between 'the ionizer and the conveyor in an electrostatic machine. e

.It will be understood, moreover, from the above description and the drawings that the electrostatic machineof the invention provides a circuit which includes the conveyor and a predetermined path of movement of the are provided in accordance with the second aspect of the invention between-the output or screen inductor member a radioactive elementor radioactive elements may be utilized in connection with an electrostatic generator having a conveyor.

and the outputlor collector ionizer connected theretoaud the exciter inductor member of the other machine. This system circuit may be closed through the two machine circuits in series by providing the connection between inductors and ionizers of the respective machine in the manner disclosed in connection with Figs. 1, 2, 3 and '10.

Although the conveyors disclosed in the drawings are in the form of cylinders with the ionizers and radio active elements disposed at the inner sideof the cylindrical walls, the inductor members being disposed at the outer side of these cylinders, the ionizers and radioactive elements may be disposed outwardly of the cylinders and the inductor members disposed inwardly thereof.

In accordance with the invention the radioactive element and a member of the machine with respect to which the radioactive element makes the ambient gas space conductive may be supported for relative movement,-

either the element or'the member or bothbeing movable.

Moreover, conveyors in the form of discs or of belts relatively movable with respect to inductor members at one side or face of the disc or belt and ionizers and radio- 1 active elements at the other side or face of the disc or belt mayfunction for electrostatic generation, ionization and conductivity of .a spaceadjacent the ionizer being secured in the manner described hereinabove.

In the above description .and in the drawings, where reference is made to ground or ground is shown conventionally, it will be understood that this term and the symbol therefor may represent the earth or a conductive,

body at what may be termed a reference potential to which connection is made, this body being of sufficient capacity totake up or to supply the required charge for operation of the electrostatic machine.

All such variations andothers which may be made within the skill of the art are intended to be within the scope of the invention.

This application is a continuation of the application of Roger Morel, Serial No. 465,395, filed October 28, 1954, now abandoned, and a continuation in part of the application of Roger Morel, Serial No. 492,494, filed March 7, 1955. 1

I claim:

1. An electrostatic machine comprising a conveyor movable in a predetermined path and capable of conveying electric charges thereon along said path, and a radioactive element disposed adjacent and in spaced relation to said conveyor at a given position along said path and capable of ionizing the space between said element and said conveyor for making said space conductive to charges to be conducted across said space between said element and said conveyor.

2. An electrostatic machine comprising a conveyor movable in a predetermined path and having a surface of substantial extent parallel to the direction of movement of said conveyor along said path, an ionizing element disposed adjacent and in spaced relation to said surface of said conveyor at a given position along said path, an inductor member disposed adjacent and in spaced relation to said conveyor in opposed relation to said ionizing element and capable of being excited at a potential to develop an electric field between saidionizi-ng element and said inductor member adjacent said surface of said conveyor, and a radioactive element disposed adjacent said given position and adjacent and in. spaced relation to said surface of said conveyor and capable of ionizing the space between said ionizing elementand said conveyor for making said space conductive to charges to be conducted across said spacebetween said ionizing element and said conveyor. I e

3. An electrostatic machine as defined in claim 2 which comprises means disposed adjacent said conveyor at a position spaced along said-path from said given position for collecting therefrom charges conveyed by said conveyor, and means operatively connected to said collect-I ing means and capable of generating electric charges from said conveyed charges, said generating means being operatively connected to said inductor member for conducting said generated charges to said'inductor member toexcite said inductor member.

4. An electrostatic machine as defined'inclaim 1 in which said conveyor is of insulating material.

-5. An: electrostatic machine as defined in claim 1 in which'said conveyor is of conductive material.

6. Electrostatic generating apparatus comprising two electrostatic generators each having a conveyor movable:

in a predetermined path, at least a selected one of said generators having a radioactive element disposed adjacent and in spaced relation to its conveyor at a given position along its path and capable of ionizingthe space between said element and said conveyor for making said space conductive to charges to be conducted across said space between said element and said conveyor, said selected generator having an inductor member disposed adjacent and in spaced relation'to said. conveyor thereof andin opposed spaced relation to said radioactive element to provide an electric field between said inductor memher and said element when said inductor member is excited at. a, predetermined potential and means for col-- lecting from the conveyor of the other generator charges in a predetermined path, each of said generators having a radioactive element disposediadjacent and inspac'ed l6 relation to its conveyor at a given position along its path andcapableof ionizing the space between said element and said conveyor for making said space conductive to charges to be conducted across said space between'said radioactive element and said conveyor, said generators each providing an inductor member disposed adjacent and in spaced relation to its conveyor and in opposed spaced relation to its radioactive element to develop an electric field between said radioactive element and said inductor member when said inductor member is excited at a predetermined potential, and means for collecting the charge conveyed by each of said conveyors and connected to the inductor member of the other generator for delivering said charge to said inductor member of said other generator for developing at the respective inductor members said predetermined potentials.

8. Electrostatic generating apparatus comprising two conveyors movable respectively in predetermining paths, said conveyors each having a surface of substantial extent parallel to the direction of movement thereof along its path, inductor members respectively disposed adjacent and in spaced relation to said conveyors at a given position along the respective paths, ionizing elements disposed adjacent and in spaced relation to said surfaces of the respective conveyors respectively adjacent said given positions and in field producing relation to the respective inductor members upon development of a predetermined potential difference between said inductor members and the respective ionizing elements, radioactive elements disposed adjacent and in spaced relation to said surfaces of the respective conveyors and adjacent the respective ionizing elements associated with said conveyors, said radioactive elements respectively being capable of ionizing the spaces between said ionizing elements and said conveyors for making said Spaces conductive to charges to be conducted across said spaces between the ionizing elements and the respective conveyors, and charge collecting means disposed in spaced relation to the respective inductor membears associated with said'conveyors along the respective J paths of movement of said conveyors for collecting charges from the respective conveyors, said collecting means'each being connected to the inductor member associated with the other conveyor.

9. Electrostatic generating apparatus as defined in claim 7, in which said collecting means comprises radioactive elements disposed adjacent and in spaced relation to the respective conveyors at positions respectively spaced along said path from said given position and capable of ionizing the spaces between said collecting radioactive elements and the respective conveyors for making said spaces conductive" to charges to be conducted across said spaces between said elements and the respective conveyors.

10. An electrostatic machine which comprises a hollow cylindrical conveyor of insulating material rotatable'on the axis of the cylinder, an inductor member disposed determined potential diiference between said inductor member and said radioactive element. v

12. An electrostatic machine which comprises a hollow cylindrical conveyor of insulating material rotatable on the axis of the cylinder, an exciterinductor member disposed adjacent and in spaced relation to a given peripheral surface of said hollow cylindrical conveyor, an exciter radioactive element disposed adjacent and in spaced relation to the other peripheral surface of said hollow cylindrical conveyor for ionizing the space between said exciter 17 radioactive element and said other surface of said conveyor in a zone adjacentsaid exciter inductor member, and a collector radioactive element disposed in spaced relation to said exciter radioactive element circumferentially of the cylinder of said conveyor about said axis of rotation and adjacent and in spaced relation to said other peripheral surface of said conveyor for ionizing the space between said collector radioactive element and said conveyor.

13. An electrostatic machine as defined in claim 12 which comprises a screen inductor member disposed adjacent and in spaced relation to said given peripheral surface of said conveyor in a zone adjacent said collector radioactive element, said screen inductor member cooperating with said collector radioactive element for effecting collecting by said collector radioactive element of charges carried by said conveyor at said other peripheral-surface thereof in the rotation of said conveyor from said zone adjacent said exciter inductor member to said zone adjacent said collector radioactive element.

14. An electrostatic machine as defined in claim which comprises an ionizing element disposed adjacent and in spaced relation to said other surface of said conveyor and adjacent said radioactive element and cooperatmg with said inductor member for developing an electric field between said inductor member and said ionizing element.

15. An electrostatic machine as defined in claim 10 which comprises a brush disposed in spaced relation to said radioactive element circumferentially of the cylinder of said conveyor about said axis of rotation, said brush engagmg said other surface of said conveyor for collecting from said conveyor charges carried by said conveyor at said other surface thereof in the rotation of said conveyor from said zone adjacent said inductor member to the zone adjacent said brush.

16. An electrostatic machine which comprises a hollow cylindrical conveyor of insulating material rotatable on the axis of the cylinder, two exciter inductor members of opposite polarity disposed in spaced relation to each other circumferentially about said axis of said cylindrical conveyor and adjacent and in spaced relation to a given peripheral surface of said cylindrical conveyor, exciter radioactive elements each disposed adjacent and in spaced relation to the other peripheral surface of said hollow cylindrical conveyor and respectively opposite to said exciter inductormembers, and collector radioactive ele-- ments disposed adjacent and in spaced relation to said other peripheral surface of said conveyor in the respective:

spaces between and circumferentially spaced from thesaid exciter radioactive elements, said collector radio'- active elements respectively being electrically connected to the respective exciter inductor members that are at the polarities of the charges collected by the respective col-- lector radioactive elements.

17. An electrostatic machine as defined in claim 1 which comprises a shield disposed adjacent said radioactive element at the side thereof away from said conveyor, said shield being capable of intercepting radiation of said radioactive element in said direction away from. said conveyor.

18. An electrostatic machine as defined in claim 1 in which said radioactive element comprises a supporting element, and a coating of'ra-dioactive material" on said supporting clement.

19. An electrostatic machine as defined in claim 1 which comprises a supporting member providing an opening therein open toward said conveyor, said radioactive: element being supported by said supporting memher adjacent said opening for radiation toward said conveyor through said opening.

20. An electrostatic machine as defined in claim 19 in which said supporting member is capable of inter-- cepting radiation from said radioactive element and has v 1a a portion thereof disposed at the'side of said radioactive element away from said conveyor.

21. An electrostatic machine comprising a conveyor movable in a predetermined path and capable of conveying electric charges thereon along said path, and a radioactive element disposed in a circuit which includes said conveyor and said path and said radioactive element and a space ionized by said radioactive element and made conductive for conducting charges across said space through said circuit.

22. An electrostatic machine comprising a conveyor movable in a predetermined path and having a surface of substantial extent parallel to the direction of movement of said conveyor along said path, ionizing elements dis posed adjacent and in spaced relation to said surface of said conveyor respectively at positions that are in spaced relation to each other along said path of movement of said conveyor, inductor members disposed adjacent and in spaced relation to said conveyor and in spaced relation to each other along said path respectively in opposed relation to said ionizing elements, said inductor members being capable of being excited at potentials to develop electric fields respectively between said ionizing elements and said inductor members adjacent said surface of said conveyor, and radioactive elements respectively disposed adjacent and in spaced relation to said surface of said conveyor and adjacent the respective ionizing elements for ionizing the spaces between said ionizing elements and said conveyor for making said spaces conductive to charges to be conducted across said spaces between the respective ionizing elements and said conveyor.

23. 'An electrostatic machine comprising a conveyor, an ionizing element, an inductor member, said ionizing element and said inductor member being disposed in opposed spaced relation to each other, said inductormemher being capable of being excited at a potential to develop an electric field between said ionizing element and said inductor member, said conveyor and said ionizing element being supported for movement of one relative to the other in a predetermined path extending transversely of said electric field, said conveyor in said relative movement becoming disposed in said field in spaced relatidn to said ionizing element and to said inductor member, charge collecting means disposed adjacent said path and spaced along said path from said ionizing element in the direction of movement of said conveyor relative to said ionizing element, said charge collecting means and said conveyor being supported for movement of one relative to the other along said path in said movement of said conveyor and said ionizing element relative to each other, said charge collecting means being disposed in relation to said conveyor for collecting from said conveyor charges conveyed by said conveyor from said ionizing element to said charge collecting means, and means operatively connected to said charge collecting means and capable of generating electric charges from said conveyed charges, said generating means being operatively connected to said inductor member for conducting said generated charges to said inductor member to excite said inductor member.

24. An electrostatic machine comprising a conveyor movable in a predetermined path and capable of conveying electric charges thereon along said path, an ionizing element disposed adjacent and spaced from said conveyor transversely of said path at a given position along said path, an inductor member disposed adjacent and spaced from said conveyor transversely of said path in opposed relation to said ionizing element in said given position, said inductor member being capable of being excited at a potential to develop an electric field between said ionizing element and said inductor member, means disposed adjacent said conveyor at a position spaced along said path from said given position in the direction of movement of said conveyor for collecting from said conveyor charges conveyed by said conveyor, and means $5 operatively connected to said collecting means and capable 19 of generating electric charg'es'from said conveyed charges, said generating means being operatively connectedto said inductor member for conducting said generated charges to said inductor member to excite said inductor member.

25. An electrostatic machine as defined in'claim 24 in which said conveyor is of insulating material.

26. Electrostatic generating apparatus comprising two electrostatic generators each having a conveyor, said conveyors respectively being movable in predetermined paths and capable of conveying electric charges thereon along the respective paths, at least a selected one of said generators having an ionizing element disposed adjacent and spaced from its conveyor transversely of said path at a given position along its path of movement, said selected generator having an inductor member disposed adjacent said path of movement of said conveyor and in opposed spaced relation to said ionizing element transversely of said path to provide an electric field between said inductor member and said'element when said inductor member is excited at a predetermined potential, means for developing on said conveyor of said other generator charges to be conveyed thereby, and means for I collecting from said conveyor of the other generator the charges conveyed thereby, said collecting means being connected to said inductor member of said selected generator for delivering said collected charges from said other generator to said inductor member of said selected generator to excite said inductor member.

27. Electrostatic generating apparatus comprising two electrostatic generators each having a conveyor, said conveyors respectively being movable in predetermined paths and capable of conveying electric charges thereon along the respective paths, each of said conveyors having an ionizing element disposed adjacent and spaced from its conveyor transversely of its path at a given position along its path of movement, said generators each providing an inductor member disposed adjacent the path of movement of its conveyor and in opposed spaced relation to its ionizing element transversely of said path to develop an electric field between said ionizing element and said inductor member when said inductor member is excited at a predetermined potential, and means for collecting thecharge conveyed by each of said conveyors and connected to the inductor member of the other generator for delivering said collected charge to said inductor member of said other generator for developing at the a respective inductor members said predetermined potentials.

28. Electrostatic generating apparatus comprisingtwo conveyors movable respectively in predetermined paths,

said conveyors each having a surface of substantial extent I parallel to the direction of movement thereof along its path, inductor members respectively disposed adjacent and spaced from said conveyors transversely of the respective paths at a given position along the respective paths, ionizing elements disposed adjacent and spaced from said surfaces of the respective conveyors respective ly adjacent said given positions and in field producing relation to the respective inductor, members upon development of a predetermined potential difference between said inductor members and the respective ionizing elements, and charge collecting means disposed in spaced relation to the respective inductor members associated with said conveyors along the respective paths of movement of said conveyors for collecting charges from the respective conveyors, said collecting means each being; w

connected to the inductor member associated with the other conveyor for delivering the respective charges to said inductor members.

29. Electrostatic generating apparatus as defined in claim 28 in which said charge collecting means associated with at least a selected one of said conveyors comprises an ionizing element disposed adjacent and spaced from said surface of said selected conveyor transversely of the path of movement of selected conveyor.

30. Electrostatic generating apparatus as defined in claim 28 which comprises screen inductor members respectively disposed in opposed relation transversely of the respective paths of movement tothe respective charge collecting means associated with the respective conveyors and connected respectively to said charge collecting means.

elements opposed thereto, said screen inductor members and the ionizing elements connected thereto being respectively connected to said inductor members associated with the other conveyor that are disposed respectively at said given positions along the respective paths of movement of said conveyors. V

32. Electrostatic generating apparatus comprising two conveyors movable respectively in predetermined paths,

said conveyors each having a surface of substantial extent parallel to the direction of movement thereof along its path, charging ionizing elements disposed adjacent and spaced from said surface of each conveyor, said charging ionizing elements associated with each conveyor being disposed in spaced relation to each other in the direction parallel to the direction of movement of said conveyor along its path, said charging ionizing elements being electrically connected together, exciter inductor members disposed adjacent and in spaced relation to each conveyor in opposed relation transversely of said path respectively to said charging ionizing elements associated with said conveyor, said exciter inductor members associated with each conveyor being electrically connected together, collector ionizing elements disposed adjacent and spaced from said surface of each conveyor, said collector ionizing elements associated with each conveyor being disposed in spaced relation to each other in the direction parallel to said path of movement of said conveyor and respectively between charging ionizing elements associated with said conveyor, said collector ionizing elements associated with each conveyor being electrically connected-together, said collector ionizing elements associated with a given conveyor being electrically connected to the exciter inductor members associated with the other conveyor.

33. Electrostatic generating apparatus as defined in claim 32 which comprises screen inductor members respectively disposed in opposed relation to and electrically connected to the collector ionizing elements associated with each conveyor.

34. Electrostatic generating apparatus which comprises a hollow conveyor of insulating material providing outer and inner coaxial cylindrical surfaces and rotatable on the axis of the cylinders, a pair of ionizing elements disposed adjacent and spaced from a selected one of said cylindrical surfaces of said hollow conveyor, said ionizing elements being disposed in spaced relation to each other in a direction parallel to said axis, an inductor member disposed adjacent and spaced from the other cylindrical surface of said hollow conveyor in opposed relation to "each of said ionizing elements, a second pair of ionizing elements disposed adjacent and spaced from said selected cylindrical surface of said hollow conveyor, said ionizing elements of said second pair being in spaced relation to each other in the direction parallel to the axis, said second pair of ionizing elements being spaced from said first pair peripherally about said axis, an inductor member disposed adjacent and spaced from said other cylindrical =surface of said hollow conveyor in opposed relation to each of said ionizing elements of said second pair, the

21 two ionizing elements that respectively are in said first pair and in said second pair and are disposed in spaced relation to each other along said axis respectively being connected to the inductor members respectively opposed thereto, the other two ionizing elements that respectively are in said first pair and in said second pair each being connected to a reference potential, said inductor members respectively disposed in opposed relation tothe two ionizing elements of the same pair being electrically connected together. i

35. Electrostatic generating apparatus which comprises a hollow conveyor of insulating material providing outer and inner coaxialcylindrical surfaces and rotatable on the axis of the cylinders, a pair of inductor members disposed adjacent and spaced from a given one of said cylindrical surfaces of said hollow conveyor and in spaced relation to each other peripherally about said axis, said inductor members each extending along said given surface in the direction parallel to the axisof said cylinder, a pair of ionizing elements disposed in opposed relation to each inductor member and adjacent and spaced from the other cylindrical surface of said hollow conveyor, said ionizing elements in each pair being disposed in spaced relation to each other ina direction parallel to said axis, the two ionizing elements that respectively are in said first pair and in said second pair and are disposed respectively toward opposite axially spaced ends of said inductor members respectively being connected to the inductor members respectively opposed thereto, said inductor members being at different potentials, the other ionizing element of each pair being connected to a reference potential that is intermediate the potentials of said inductor members.

36. Electrostatic generating. apparatus as defined in claim 35 whichcomprises a wall of insulating material disposed within said hollow conveyor and extending transversely of the axis of the cylinders and between the two axially spaced ionizers of each of said pairs.

37. Electrostatic generating apparatus which comprises a hollow conveyor of insulating material providing outer and inner coaxial cylindrical surfaces and rotatable on the axis of the cylinders, two exciter inductor members of opposite polarity disposed in spaced relation to each other circumferentially about said axis of said cylinders and adjacent and spaced from a given peripheral cylindrical surface of said conveyor, charging ionizing elements disposed adjacent and spacedfrom the other cylindricalperipheral surface of said hollow conveyor and respectively in opposed relation to said exciter inductor members, and collector ionizing elements disposed adjacent and spaced from said other cylindrical peripheral surface of said conveyor in the respective spaces between andcircumferentially spaced from said charging ionizing elements, said collector ionizing elements respectively being electrically connected to the respective exciter inductor members that are at the polarities of the charges collected by the respective collector ionizing elements.

38. An electrostatic machine comprising a conveyor,

, an input electrode, an inductor member, said input electrode and said inductor member being disposed in opposed relation to each other, said inductor member being capable of being excited at a potential to develop an electric field between said input electrode and said inductor member, said conveyor and said input electrode being supported for movement of one relative to the other in a predetermined path extending transversely of said electric field, charge collecting means disposed adjacent said path and spaced along said path from said input electrode in the direction of movement of said conveyor relative to said input electrode, said charge collecting means and said conveyor being supported for movement of one relative to the other along said path in said movement of said conveyor and said input electrode relative to each other, said charge collecting means being disposed in relation to said conveyor for collecting from said conveyor charges conveyed by said conveyor from said input electrode to said charge collecting means, means operatively connected to said charge collecting means and capable of converting charges collected by said collecting means to charges for exciting said inductor member, and means connected to said converting means and to said inductor member for delivering said converted charges to said inductor member.

39. An electrostatic machine comprising a conveyor of insulating material, an ionizing element, an inductor member, said ionizing element and said inductor member being disposed in opposed spaced relation to each other, said inductor member being capable of being excited at a potential to develop an electric field between said ionizing element and said inductor member, said conveyor and said ionizing element being supported for movement of one relative to the other in a predetermined path extending transversely of said electric field, said conveyor in said relative movement becoming disposed in said field in spaced relation to said ionizing element and to said inductor member, charge collecting means disposed adjacent said path and spaced along said path from said ionizing element in the direction of movement of said conveyor relative to said ionizing element, said charge collecting means and said conveyor being supported for movement of one'relative to the other along said path in said movement of said conveyor and said ionizing element relative to each other, said charge collecting means being disposed in relation to said conveyor for collecting from said conveyor charges conveyed by said conveyor from said ionizing element to said charge collecting means, means operatively connected to said charge collecting means and capable of converting charges collected by said collecting means and having a given polarity at a given potential to charges of opposite polarity at a selected potential, and means connected to said converting means and to said inductor member for delivering said charges of opposite polarity and selected potential to said inductor member for exciting said inductor member.

No references cited.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,831,988 April 22, 1958 Roger More].

It is hereby certified that error appears in the-printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected belo Y Column 16, line 18, for "predetermining" read =-predetermined-==,

Signed and sealed this 7th day of October 1958.

(SEAL) Attest:

KARL H AXLINE ROBERT C. WATSON Attesting Ofiicer Commissioner of Patents UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION v Patent No. 2,831,988 April 22, 1958 Roger Morel It is herebfi certified that error appears in the-printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 16, line 18, for "predetermining" read --=predetermined-=- Signed and sealed this 7th day of October 1958u (SEAL) Attest:

Attesting Officer Commissioner of Patents

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