US1851532A - Luminous electrical discharge device - Google Patents

Description

March 29, 1932- R. E. VOLLRATH LUMINOUS ELECTRICAL DISCHARGE DEVICE Filed July 22,

INVENTOR.

A TTORNEY.

Patented Mar. 29, 1932 PATENT2 OFFICE RICHARD E. VOLLRATH, OF PASADENA, CALIFORNIA LuMINoUs ELECTRICAL DISCHARGE DEviCE Application filed. July 22,

now in extensive use, the gas pressure 1n the j l tube is usually adjusted to give a uniform steady glow which fills 'the tube.

I have found that electr-ical dischargesA through gases, that are confined in a transparent container, may be altered in a striking Z3 manner, when such container is lled with 4 granules or dielectric and insulating material such as glass or quartz. L x The invention is illustrated in the accompanying drawings, wherein Fig. l shows a luminous tubular discharge ,device in side elevation, in which my invention is embodied. y

Fig. 2. illustrates the same in vertical longitudinal section. 20 Fig. 3 shows a .cross-sectional' detail through the same,-the section being-taken on the line,3-- 3 of Fig. 2.

Fi g. 4 illustrates the invention in a slightly modified form of tube'. v

Fig. 5 shows v a cross-sectional detail through the same as viewed on the line 5 5' of Fi g. 4.

Fig. 6 illustrates another embodiment of the invention.

Fig. v7 shows a cross-sectional detail through the same as viewed on the line 7-7 of Fig. 6, and Fig. 8 illustrates another shape of tube in which my invention is embodied. `Referring particularly to Figs., 1, 2 Aand 3 the numeral 10 designates a transparent container, which in the present instance lhas the form of a cylindrical glass tube, provided on the interior thereof, near each of its opposite ends, with electrodes 11 and 12 and suit-l d uated, then filled with a gas at reduced pressure and finally sealed,-the teat 17 indi- 1930. serial N6. 469,787.

able lead wires 13 and 14 whose inner ends are connected to said electrodes. These lead- Wires are sealed into the tubes vacuum-tight and serve to connect the electrodes with a current-supply through a suitable transformer 15.

The tube 1() is practically filled with dielectric or insulating material in the form of granules 16.

'lhese granules or particles with which the tube is filled maybe composed of quartz, glass, or any insulating material which is not destroyed under the influence of the' electrcal discharge, and they may be of any geometrical shape With either smo-oth or irregular surfaces. If glass or some other insulating ceramic material is employed, it may have the form of beads or of fragments obtained by crushing larger pieces of the' material. v

Colored granules maybe employed if desired to produce different effects.

One of the most advantageous materials, from a cost pointG of view, is pure quartz sand, known .as Ottawa sand, which may be obtained in a`variety of sizes with almost .spherical grains. The rounded form ofthese grains is of some advantage because it al' lows the sand to readily flow into bent tubes during the process of manufacture vand this particular quartz sand has low absorptive f lpower for gases. This is important. in case lthe gas to be employed is one of the rare gases of atmosphere, such as neon, whose luminous properties are extremely sensitive to any gaseous impurities which might escape from inadequately-outgassed granulesduring the operation of the tube. l

The tube containing'the granules is evaceating the vpoint at which these operations take place.

All of these operations are well known to those familiar with the manufacture of discharge tubes and therefore form no part of the present invention. v

The kind of gas employed may also be Ivaried, asit is known that neon gas willproduce a different colored effect `from that which helium gas will produce so that vari- .ous colored effects may be produced accordcharge-tube and follows an extremely crooked or zig-zag path through the spaces bctween the granules lying near this wall surface or in contact with it substantially as shown by zig-zag lines in Fig. 1.

I have found thatthis discharge takes place most readily when the electrodes 11 and 12 are in close contact with the surface along which the discharge is to take place, and for this reason I have arranged the electrodes in close contact with the wall of the tube, as clearly shown in the drawings.

A most curious and striking property of the discharge is that it does not follow the same channels persistently, but frequently shifts from one set or group of channels to another, thus giving the luminous veins the appearance of moving vabout verratically. The effect produced is therefore likened to a. rapid sequence of brilliant lightning flashes within the tube and presents the appearance of motion which is most effective in ,advertising displays in attracting attention.

The effect is thus produced `without resorting to the use of any switching or mechanical devices to produce the appearance of motion.

A ylighter construction of discharge-tube may be gained by means of they structure shown in Figs. 4 and 5, wherein, 18 designates an outer transparent glass tube in which there is formed orlocated an inner central tube 19.

,',Ihe same electrodes 11 and 12 may be used at opposite ends ofthe tube, and a lead wire 13l may enter the tubeV atxonevend and be attached to the electrode/11". Atthe opposite end, the' tube 18 may have a lateral nipple 2() through which a lead wire 14 to the other electrode 12 may be passed.

The filler 16 will then be confined in the space between the outer andinner tubes so that the. inner tube will displace the heavier` quartz filler and therefore structure. Y

The manner of forming the inner and outer tubes is'of no importance.

There is a tendency with this straight wall type of inner tube for some of the discharge produce a lighter tn run along the outer wall 'of the inner tube where it cannot be readily seen, owing to the interposition of the granules between the tubes, and I find that the effect is prevented by providing an inner tube 21, of an irregularl shape with a series of annular enlargements 22 as shown in Figs. 6 and 7. In this form the path along the central tube is long, due to the enlargements, and therefore the: discharge will follow the shorter path along the inner wall of the container. The distance between the inner and outer tube of Figs. 4 and 5 may be made so small as to permit the interposition of onlyone layer of granules. In thisjcase, discharges along the inner tube are equally as visible as those along the inner wall of the container. t

-In Fig. 8, the structures are substantially the same as those in Figs. 1 and 2`witli the eX- ception that the tube 23 is of a semi-circular shane.

Having described my invention, I claim,-

1. An electric discharge device comprising a sealed transparent container having a gas therein. electrodes having terminals. within the container and a granular filler in the gasfilled container the granules of which form numerous channels-between the electrodes .for

the passage of the discharge between the electrodes. n

2. An electric discharge device comprising a transparent outer container with gas therein. van inner displacing element in said con-A tainer, electrodes having terminals exposed infthe space between said outer container and the said inner element and a filler of granular insulating material in said space between said electrodes. "f'

3. An electric discharge device comprising a ,transparent container having gas therein, spaced electrodes in the container and in contact with the inner wall thereof and a granular filler in the container between said electrodes said filler forming: numerous channels for the passage of discharge between the electrodes and producing the effect of moving luminous veins in the container.

4.- An electric discharge device comprisingv a transparent outer tube with a gas therein, an inner tube spaced from the outer tube, a gran-, ula'r filler in said space between the outer and inner tubes and spaced electrodes in the outer tube. i

5. An electric discharge device comprising a transparent outer tube with a gas therein,

an inner tube spaced from the outer tube, said innertube having enlargements at spaced intervals, spaced electrodes in the space between the outer and inner tubes and a granular -filler in said space between said electrodes.

In testimony whereof Iv affix inv signature.

RICHARD E. VOILRATH.

Images