US2283013A - Spark gap device - Google Patents

Description

May 12, 1942. F.' E. Nul- L SPARK' GAP DEVICE Filed Apg. 3l. 1940 4 Sheetvs-Sheet l wmf'fff A M MVM ATTORNEYS May 12, 1942. F. E. NULL sPARK GAP DEVICE 4 Sheets-Sheet 2 Filed Aug. 3l, 1940 INVENTOR BY. WV

ATTORNE May l2, 1942. A F. E. NULL l 2,283,013

SPARK GAP DEVICE 'Filed Aug. 31, 1940 4 sheets-sheet s May 12, 1942.A E, NULL 2,283,013'

SPARK' GAP DEVICE Filed Aug. s1, 41940 4 sheets-sheet 4 l J I ATTORNEYS4 Patented May 12, 1942 UNITED lSTATE.

s PATENT oFFlcE 20 Claims.

This invention relates to an improved spark gap device for generating Ylight and has for an object to provide a structure which will produce a long substantially straight ultra-violet spark.

Another object of the invention is to provide a construction which will preserve the high einciency of the long high voltage spark while maintaining a line spark.

A further object of the invention is to provide a sparking device with means for reflecting light in such a way as to pass from an enclosing housing to a point exterior thereof through a narrow window.

A further object is to vprovide a sparking device including a housing and a window through which the light from the sparking device is projected, with the construction of the window such that it may be interchanged to allow at one time the light to be focused through the window and at another time the light to be utilized within the housing.

A more detailed object of the invention is to provide in a spark gap device a window and a metal rod adjacent the window positioned to prevent the puncture of the window when Abombarded by ions from the sparking device.

An additional object is to provide a. sparking device within a housing and, with means for separation of the housing by a series of insulating baffles so that the irradiated substance A will not short-circuit the path o f the spark.

In producing sparks, it has been difcult heretofore to produce a long intense high voltage spark that will travel in a substantially straight line. The luminosity of a spark is greater than any other known source of light and when the spark ismaintained in a substantially straight line certain desirable results will be secured. In the present invention means have been provided through the use of alined electrodesspaced a short distance apart for maintaining the spark substantially in a straight line. Also, as shown in the accompanying drawings, a substantially sound-proof housing is providedwith a quartz or glass window through which light is emitted when it is desired to use the same exteriorly of the housing. While in the accompanying drawings, a comparatively large number of spark terminals are presented, it will be evident that two or more electrodes or terminals may be used with high voltage, as, for instance, 100,000 volts, without objectionable action on the terminals or electrodes and without noise.

In the accompanying drawings- Fig. 1 is a longitudinal vertical Sectional view through aA spark gap device disclosing an embodiment of the invention;

Fig. 2 is a detail fragmentary sectional view through one of the terminal supporting members shown in Fig. 1; Fig. 3 is a sectional view through Fig. 2 approximately on the line 3 3;

Fig. 4 is a sectional view through Fig. 1 approximately on the line 4 4;

Fig. 5 is a diagram of the wiring lshown in connection with'the structure shown in Fig. 1;

Fig. 6 is a view similar Yto Fig. l but showing a modified structure;

Fig. 7 is a sectional view through Fig. 6V approximately on the line 1 1;

Fig. 8 is a sectional view through Fig. 6 approximately on the line 8 8;

Fig. 9 is an enlarged fragmentaryview showing a part of the center of the structure shown in Fig. v6 and illustrating how articles to be treated are supported near ,the spark, the same being taken on a section through Fig. 10 on the line 9 9; Y

Fig. 1 0 is a front view of the structure shown in Fig. 9 with certain parts broken away.V

Referring to the accompanying drawings by numerals, in Yparticular Fig. 5, a circuit is disclosed wherein there is provided a transformer I to transform line current to a high voltage current, as,Y for instance, a voltage of 100,000 volts or more. In the secondary circuit -of the transformer there is provided a reactance bar 2 and a condenser 3. Across the condenser 3 there is provided a sparking device 4, which is shown in detail in Figs. 1 and 4. If the sparking device 4 consists of only two terminals spaced apart there will be merely one spark passing from one terminal to the other.V However, the sparking device 4 is of special construction as illustrated especially in Fig. 1.y In this device there is provided a housing 5, which is formed with inner and outer walls 6 and 1 and between these walls a packing 8 of sound-insulating material is placed. The inner and outer walls maybe of metal, if desired, and the packing 8 may be wool or any other sound-deadening material.

The wires I' and I" Vshown in Fig. 5 are the wires I and I shown in Fig. 1, whereby it will be seen that current is impressed on the plate 9 which is electrically connected with one side of the condenser 3.` Wire I" is connected with lead-in wire I0, which is surrounded by a heavy insulating covering Il. Wire I0 Vis electrically connected with the inner'wall I2 of the condenser 3. A number o f layers I ci paper or similar material are arranged between the inner and outer walls of the condenser. Condenser oil I4 may be inserted throughthe filling neck I5 at any time. This oil passes through the various perforations I8 and maintains the layers of paper I3 Well oiled so that the condenser will stand the high voltage impressed thereon. One terminal of the condenser is grounded on the plate 9 and the metallic casing I1, while the other terminal of the condenser is connected to one of the electrodes I8 by a metal braided cable I9 which is secured by a bolt 28 or otherwise to a bracket 2I electrically connected with the inner tube or casing I2. It will, therefore, be seen that whenever a suflicient charge is impressed on the condenser 3, a spark will jump from one electrode I8 to the other and eventually pass along a flexible and preferably braided cable 22 to the casing I1 to which the cable 22 is bolted or otherwise rigidly secured. If the spark jumped freely through the air from the cable I9 tothe cable 22, it would be exceedingly irregular and zigzag. By providing a number of terminals I8 in a straight line, the spark will pass from one electrode or terminal to the other and thereby produce a long, continuous and substantially straight spark with high voltage. As shown in Figs. 2 andv 3, each of the terminals or electrodes I8 consists of a round terminal member I8 which maybe tungsten, molybdenum, or other desirable metal conducting material. Each of the members I8 is preferably formed with a groove 23 around which is looped a strand of wire 24 which is thenrtwisted into a cable 25 and this cable is inserted into a vitreous support 26, which may be glass,`porcelain, or other material. Cement-21 is used to rrnly hold the cable 25 in the support 26. This cable is somewhat flexible but ordinarily will remain straight as indicated in Figs. 1 and 2. The support 28 has one end positioned in a bore or aperture V28 formedV in an insulating support 29 which may be of anydesired material. Each of the supports 26 is held rigidly in place by a-set screw 38, as shown in Fig. 3. The support 29 may be of any. desired insulating material-which will withstand an appreciable amount of heat. The support 29 isk provided with slots 3| and 32 and small plates 33 and 34 are fitted therein. Each of these plates'is rotatably mounted in a Support. The plate 33 is rotatably mounted in an insulating support 35 which is secured by a set screw or otherwise to the housing I1, while plate 34 has an extension 34 rotatably mounted in a tubular member 36 secured to a pipe 31. Pipe 31, in addition, has the frame 38 of a mirror 39 bolted or otherwise rigidly secured thereto. The upper part 38 of frame 38 is bolted or otherwise rigidly secured to posts 48 and 4I which, in turn, are bolted or V otherwise rigidly secured to the inner casingv I1, whereby the lmirror 319 is rigidly supported. As shown in Fig. 4, the mirror 39 is formed and positioned to kfocus light from the electrodes I8 at point 42V which is exterior of the window 43. Window 43 is provided with a frame 44 which may be felt or other yielding and nonsound-producing material. A sliding frame 45 of metal or other desirable material slidingly nts into the casing44 and is provided with spaced window panes 46 and 41. These window panes may be Aglass though preferably they are quartz andare supported on a lining 45' of felt or lother non-sound-producing material and are spaced apart on'both sides and ,on top and bottom by felt linings 48. This window is comparatively narrow and, consequently, even if expensive quartz is used, the expense will not be prohibitive because of the fact that the window is very narrow though comparatively long. This window allows the ultra-violet rays to pass through the same but will prevent sound from passing, and, consequently, the device, as far as the workmen are concerned, is substantially noiseless.

Each time a spark is produced, which may be once each second or many times a second, there will be produced ions at the various electrodes. In order to reduce the ions and to maintain the respective electrodes I8, there is provided means for blowing the ions out through the opening 49,

' as shown in Fig. 1. In the structure shown in Fig. 1, all the electrodes I8 are in line and, consequently, one discharge opening E0 connected with the pipe 31 is sufcient to provide a blast ofI gas or air to blow the ions away. This gas or air may be constant or it may function between the sparkings of the device.

Where thel device is operating rapidly there will naturally be .af certain amount of overlapping of the actions of the gas'and the sparking at the Variousv terminals. Gas or air from any suitable source, -undersome appreciable pressure, is -led in through the pipeY 5I and then through a flexible hose 52 tothe pipe-31. This iexible hose is desired because sometimes. the .support 29 is swung one way-or the other to properly line up the respective `electrodes I8 with the mir-ror and the window 43. As ,theY cables I9 and 22 are flexible and somewhat extensible, this swinging movement which is usually very small may be readilyaccomplished without adjusting any of the parts.

Under some circumstances, as hereinafter fully described, it is desirable to provide a jet of air or gas for each of the electrodes I8 and when this is` the case the upstanding pipe 53 is used. This pipe has an outlet nozzle 54 adjacent each terminal I8. The lower end of the pipe 53 is carried by a pipe 55 which is pivotally mounted at 56 on an insulating plate 51, which plate may be readily secured vto an insulating sleeve 58. When the pipe 53 is in use, lthe tube or hose 52 is disconnected from the end 31', as shown in Fig. 1 and is'connected to a tubular extension 55'. When this occurs 'the discharge nozzle 50 becomes inoperative and air or gas will pass out the respective nozzles 54. As shown in Fig. 4, the pipe 55 is swung to one side and is out of the way when the nozzle 50 is in use. However, when the respective nozzles 54 are to be used, they are swung around to a point near the electrodes I 8.V As shown in Fig. 4, an insulating plate 59 is pivotally mounted at 69 and when swung to the-position shown in Fig.,4 it is out of the way and is non-functioning. However, under some circumstances, it is swung over toward the electrodes I8, as illustrated in Fig. 8. This is done when the'various nozzles 54 are -being used as shown in Fig. 8 by having'this insulating protecting plate arranged as shown in Fig. 8. The ions blown away from the yspark electrodes cannot fog or dirty the mirror` 39. Y

When the pipe-53 and associate partsare used, preferablyvthe modified form 'of window and associate parts shown in Fig. 6 to 10 inclusive, is used. When the structure shown in Fig. lis used, the article to be irradiated is placed exteriorly of the window at or near the point 42. However, sometimes -it is desired to treat substances very near the spark and when this is the case the sliding part of the Window 43 is removed and a new sliding part consisting generally of members 6I and62 is substituted. These are rectangular tubular members, member 6I being open at both ends while member 62 is closed at both ends except for either one large opening 63 as shown in Fig. 6, or a `number of smaller openings 64 as shown in Fig. 10. Themember 62 is preferably formed of insulating material, as well as member 6I, the openingV 63 being rectangular. A support 65 of any desired kind is provided for supporting one or more articles to be treated by the spark. It will befobserved that the spark cannot pass through the window because of the wall 62', which is of insulating material. In this form of the invention, the pipe 53 with its nozzles 54 isvused and the ions are blown at right angles to the spark so that they will pass out through the opening 66, as shown in Fig. 8. By reason of this path ofV movement of the ions, the insulating plate 59 is swung over to the position shown in Fig. `8 to prevent fogging of the mirror 39. The mirror 39, under these circumstances, is idle as'the ultra-violet rays act directly on the material supported by the member 65. By sliding the member 62 toward or from the spark more or less intensity of action may be secured.

As shown in Figs. 9 and 10, the same arrangement as shown in Fig. 8 is disclosed except that the quartz plate 61 has insulating division members 68 secured thereto and pans or other supports 69 mounted thereon. Olive oil or other material to be treated with ultra-violet rays is arranged in the pans 69, which pans may be glass or other desired material. As the parts are close to the supporting electrodes I8, there isl some danger of the spark penetrating the quartz panel 61. To reduce this to a minimum, metal bars or rods 1U are cemented or otherwise secured to the quartz panel 61 in line with the respective insulating shelves 68. The ions will bombard these metal rods 10 and, consequently, will not injuriously affect the quartz panel 61.

It will be noted thatby using a series of insulated electrodes, the spark path is anchored in place without reduction in the eiciency of the light production- The electrodes I8 may be made of tungsten or molybdenum and, consequently, being made of this material will wear but lit-v tle and can readily be replaced in the apparatus at any time. The double-walled metallic housing not only acts as a sound-proof structure but is used as an electrostatic shield. It will be noted that as soon as the condenser 3 discharges the voltage across the various electrodes or terminals I8 immediately drops to zero because of the action of the reactance choke coil 2, which is in series with the condenser and source of voltagev In a small fraction of the interval required for the condenser to recharge and the voltage across its`terminals to rise to a sufcient value to discharge across the various electrodes I8 again, the gas or air blast will function and drive most of the ions produced by the former spark away from the gaps so that they will not materially lower the voltage required to cause the spark to discharge. when it is desired to have the maximum intensity of light strike the specimens being treated, the number of discharges per second can be greatly increased by lowering the action of the choke 2 that is used in series with the spark 4, as shown in Fig. 5. When an adjustment of this kind is used, a separate nozzle 54 for each electrode I8 is preferably used so as to maintain a uniform` action for the device.

With the arrangement described,

I' Any'source of high voltage may be used to produce the spark. vIn'other words, the ener-V gizing circuit may use AKC. or DrC. or intermittent current. If-'A.`C. voltageis available lat lth'e usual 110v or 220 volts, a transformer is used to step the voltage up tothe 100,000 volts required to charge the condenser :for the high voltage spark. The use of a Vtransformer is obviated when D. C. high voltage sources are available.

In order to prevent the housing from becoming too greatly heated, there is provided an inlet pipe 1I and an outlet pipe 12 connected with an encircling chamber 13. This permits cold water or other cooling element to flow around the inner casing or housing and maintain the temperature at a desired point.

I claim:

1. A spark gap device for producing a long high voltage spark'with the spark in a substantially straight line, consisting of a row of spaced electrodes arranged in a line, a condenser, means connecting the terminals of said condenser to the two end electrodes respectively of said row of electrodes, a source of high 'voltage supply, and means connecting said high voltage supply to said condenser.

2.' In a device of the character described, a row of anchored insulated electrodes with short gaps therebetween, andmeans for impressing a high voltage current on the end electrodes of said row for producing a long high voltage spark extending across all of said gaps so as to generate ultraviolet light.

3. In a light source, means for producing a long high voltage spark, afrow of 'insulated electrodes positioned to anchor said spark and cause the same to move in a straight line.

.. 4. In a light source, means for producing a long high voltage spark, a` row of electrodes for anchoring said spark, 'an electrostatic shield and sound-proofing housing surrounding said electrodes and spark provided with a quartz window, and a mirror for-'reflecting the light from said spark through said window and focusing the light beyond 'the window. v' f l `5. In a light source, means Yfor producing a long spark, a housing functioning as an electrostatic shield,'means forV supporting articles to be irradiated by said spark, a quartz window between said spark and said articles, and insulating baflles positioned between the respective articles to prevent saidlong spark from being short-circuited while exerting full value on said articles.

6. In alight source, means for producing a long spark, a housing enclosing said means having a quartz window positioned near said long spark, a plurality of shielding metal members secured to said window on the side nearest said long spark so that ions in the pre-breakdown current will bombard the metal members and thereby shield the quartz window, and means for supporting articles to be treated near saidv window on the opposite side to said metal members,

7. In a device of the character described, an insulating board having a plurality of aligned holes, a hollow support of refractory material tted in each of said holes and extending therefrom, a twisted wire cable extending into each Aof said hollow supports, cement for securing said cables in place, a spark terminal carried by each ized by means for directing a blast of gaseous matter across said electrodes immediately after each sparking operation.

9. A device as set forth in claim2, characterized by means extending-to near each of said electrodes for individually blowing the ions away from the vicinity of the electrodes immediately at the completion of each spark.

10. A light; source comprising a row of spaced metal electrodes arranged in alignment, means for insulating said electrodes from each other, a condenser having opposite sides connected electrically with the respective electrodes on opposite ends of said row and a source of current charging said' condenser whereby when said source of current is functioning sparks will be formed between said electrodes so as to present a long straight-line spark- 11. In a source of light, means for producing a straight long spark zone comprising a row of double-end electrodes arranged in axial alignment and spaced apart a distance less than they are long, and meansfor supplying current intermittently at high voltage to said row of electrodes.

12. In a light source, a plurality of spaced metal electrodes arranged in a row, a condenser having its opposite sides connected to said row at opposite ends, means for charging said condenser, and means acting as an electrostatic shield and sound-proofing structure enclosing said electrodes. Y

13. In a light source, means for producing sparks in a row, a housing for said means provided with a window, and a mirror for directing light from said row through said Window.

14.111 a light source, means for` producing sparks in a row, a sound-proof housing for said means, said Vhousing having a window, and means for directing uid between said sparks to deionize the gaps between sparks.

15. In a light source, means including a row of spaced metallic guides for producing a row of sparks, means for directing jets ofgas between said metallic guides to de-ionize the gaps between sparks, means for charging said guides with electric current, and a mirror for reflecting light from said spark in a certain direction.

16. In a device of the character described, a row of spaced spark guides, means for producing a spark between the respective guides simultaneously, a housing enclosing said guides, said housing being provided with a window and a vent opening, a'mirror positioned to reflect light from said spark through said window, and means for Y directing gaseous matter past said spark guides toward said vent to prevent fogging of said mirror.

17. In a device ofthe character described, a

Vsparking structure, means for producing sparks at said sparkingstructure, a sound-proof housing for said sparking structure provided with a vent and a window, said Window including a plurality of parallel transparent quartz plates and yieldingsound-absorbing material for holding said plates in position, a mirror for directing light from said sparking structure through said window and means for directing a de-ionizing gaseous material past said sparking structure toward said vent for preventing fogging of said mirror.

18. In a device of the character described, a sparking device including a condenser, a supporting board, a plurality of tubular supports carried by said board, an electrode carried by each of said tubular supports, means for connecting one side of said condenser to the electrode at one end, and means for connecting the other side of said ,condenser with the electrode on the opposite end, whereby when the device is :functioning there will be produced a line of sparks.

19. In a device of the character described, a sparking device comprising a support of insulating material, a plurality of spaced electrodes carried by'said support, each of said electrodes including a conductor bar, a supporting metal cable, a hollow vitreous post into which one end of the cable extends and means for removably securing said post to [said support, the conducting bars of the respective electrodes being parallel to one edge of said support and in spaced axial alignment, a condenser, electric conducting means for connecting one side of the condenser with an electrode at one end of said support, and electric conducting meansconnecting the opposite side of the condenser with the electrode at the opposite end ofsaid support.

20. In a device ofthe character described, a sparking device and asound-proof housing for said device, said housing including a double` walled enclosure provided with sound-proong material between the walls, a Vent at the top of the housing, and a Window in the side of the housing, said window comprising a frame, a plurality of parallel transparent plates arranged in said frame, and yielding means carried by said frame for yieldingly supporting said transparent plates.

FAY E. NULL.

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